oe 3 . vay stage SESea nah Bigaes Se ry Honea _ UNIVERSITY OF ILLINOIS LIBRARY BOOK CLASS VOLUME | Tae tae GIOS toc. 27) me fi F ‘ ‘a - ; £ ¥ rs H « oy Ve. i, “q i - ; p 3 s t ; 4 } - - ¥ s a ’ : ‘ ; ‘ ' OE 2 7 y 4 A REFERENCE HANDBOOK OF THE MEDICAL SCIENCES ~ SCIENTIFIC AND PRACTICAL MEDICINE AND ALLIED SCIENCE Beveov Van lOUS. WRITE RS A NEW EDITION, COMPLETELY REVISED AND REWRITTEN EDITED BY ALBERT H. BUCK, M.D New Yor« Crry VOLUME II. ILLUSTRATED BY NUMEROUS CHROMOLITHOGRAPHS AND SEVEN HUNDRED AND SIXTY-FIVE HALF-TONE AND WOOD ENGRAVINGS NEW YORK WILLIAM WOOD AND COMPANY MDCCCCI ’ Te ee | Pe ba ee, aye re > é _ . - on - La hes 7. ve > fl? ho -~ Ny - on * bun = * a. ty -_s 7 2 Ds ‘PY we ay) - 7“ Pegs r ety Geen Z . ; i 2, P y ed < ® iis ee x v~ aa ,/ + MG ‘> iB ae » 7 ' “ J ; \ - a - ae 2. “y AD es & ° £ A a 2 e > 4 . itty VL Hee bo ae oe / \ /\4 1 c ’ oT ——~ : : eF . 6 | ba ( COPYRIGHT, 1901, — By WILLIAM WOOD AND COMPANY } % : & - . . Phd 82-94 LAFAYETTE PLACE, NEW YORK , SAS aM « ; é - u v4 * ‘ > . 7 Ws met) ten ay ie ant ip Aare Z : 2 7 ) feet New York, N. Y. T. MITCHELL PRUDDEN, M.D., LL.D........ New VORK NGL Ye Professor of Pathology, and Director of the Labora- tories of Histology, Pathology, Bacteriology, and Clinical Microscopy, Medical Department of Colum- bia University. MARY PUTNAM-JACOBI, M.D....NEw York, N. Y. Visiting Physician, St. Mark’s Hospital. LHOPOLD (POUTZHL, At Der. sea New York, N. Y. JOSEPH RANSOHOFF, M.D CINCINNATI, OHIO. Professor of Anatomy and Clinical Surgery, Medical College of Ohio; Surgeon to the Cincinnati, Good Samaritan, and Jewish Hospitals. IRVING OC. ROSSE, M.D., F.R.G.S..... WASHINGTON, D.C Lately Professor of Diseases of the Nervous System, Medical Department, Georgetown University. HENRY) HeRUsb YM Dao. canes New York, N. Y. Professor of Materia Medica and Pharmacology, in the University and Bellevue Hospital Medical College, and in the New York College of Pharmacy. OTTO" H, SCHULTZE, MD rans: Instructor in Gross Pathology, Cornell University Med- ical College in New York City; Professor of Pathol- ogy, Medical Department, University of Vermont; formerly, Coroner’s Physician of New York County. R. Jak SCOTT, A.D WuitE Puarns, N. Y. Attending Physician, Bellevue Hospital, Out-Patient Department. NICHOLAS SENN, M.D., LL.D....... CricaGgo, Inu. Professor of Surgery, Rush Medical College; Attend- ing Surgeon, Presbyterian Hospital; Surgeon-in- Chief, St. Joseph’s Hospital. JOHN V. SHOEMAKER, M.D., LL.D DELPHIA, PA. Professor of Materia Medica, Pharmacology, Thera- peutics, and Clinical Medicine, and Clinical Profes- sor of Diseases of the Skin, The Medico-Chirurgical College of Philadelphia; Physician to the Medico- Chirurgical Hospital. sees ew eee LIST OF CONTRIBUTORS TO VOLUME IL. BEAUMONT SMALL, M.D........ OrTTawa, CANADA. Attending Physician, St. Luke’s General Hospital, Ottawa; Consulting Physician, The Children’s Hos- pital; Late Examiner in Materia Medica, College of Physicians and Surgeons, Ontario. Demo LON SMITH, M.D.. i ic..0.s Boston, Mass. Assistant Physician, Department for Skin and Venereal Diseases, Boston Dispensary. PHO Ne on SOLOMON: Mabon oss. > LOUISVILLE, Ky. Professor of Materia Medica and Therapeutics and of Clinical Medicine, Medical Department, Kentucky University ; Pathologist, Louisville City Hospital. M. ALLEN STARR, Pu.D., M.D...New York, N. Y. Professor of Diseases of the Mindand Nervous System, Medical Department, Columbia University ; Consult- ing Physician, Presbyterian, St. Vincent’s, and St. Mary’s Hospitals, and the New York Eye and Ear Infirmary. Hew SteENSULAND, M.D..........: Syracuse, N, Y. Lecturer on Pathology, College of Medicine, Syracuse University ; Pathologist to St. Joseph’s Hospital, the Hospital of the Good Shepherd, and the Hospital for Women and Children. ENOCH VINE STODDARD, M.D....... ROCHESTER, N. Y . Emeritus Professor of Materia Medica and Therapeu- tics, University of Buffalo; Consulting Physician, Rochester City Hospital; Late Commissioner of Health, Rochester, N. Y. EMMANUEL J. STOUT, M.D....Patapepnta, Pa. Instructor in Dermatology, Jefferson Medical College; Associate Physician, Northern Dispensary, Depart- ment of Skin Diseases. HENRY LING TAYLOR, M.D....NeEw York, N. Y. Assistant Orthopedic Surgeon, Hospital for Ruptured and Crippled; Consulting Orthopedic Surgeon, New York State Epileptic Colony, Sonyea, N. Y WILLIAM H. THOMSON, M.D....NEw Yorks, N. Y. Visiting Physician, Roosevelt Hospital. LOUIS McLANE TIFFANY, M.D...Bautrworg, Mp. Professor of Surgery, Medical Department, University of Maryland. ae ELIZABETH WALKER, M.D....NEw York, ms Clinical Assistant, Hospital for the Relief of the Rup- tured and Crippled. BRN RYSA BauW AR DP rel ieee ss sects: Lincoun, NEB. Professor of Zoology, University of Nebraska; Zoolo- gist of the State Board of Agriculture. MOSES C. WHITE, M.D.*...... New Haven, Conn. Formerly Professor of Pathology, Medical Department, Yale University. BOY ADE WHITMAN MoDers. cae: New York, N. Y. Chief of Clinic and Instructor in Orthopedic Surgery, Medical Department, Columbia University. JAMES T. WHITTAKER, M.D.*..Crnctnnati, Onto. Formerly Professor of the Theory and Practice of Med- icine, Medical College of Ohio, Cincinnati. BURG. WILDER, Mibrasonscceeet se IrHaca, N. Y. Professor of Neurology, Vertebrate Zoology, and Phys- iology, Cornell University. LIGHTNER WITMER, M.D...... PHILADELPHIA, Pa, Assistant Professor of Psychology, University of Penn- sylvania; Psychologist tothe Pennsylvania Training School for Feeble-Minded Children. JOHN McGRAW WOODBURY, M.D., M.R.C.S..... New York, N. Y. Instructor in Orthopedic Surgery, Cornell University Medical College in New York City. * Died while the volume was in course of preparation. A REFERENCE .HANDBOOK OF THE MEDICAL SCIENCES. BLASTODERM.—Blastoderm is a term of somewhat varied signification according to the animal to which it is applied, and, indeed, according to the stage of de- velopment. The blastoderm of vertebrates is different from the so-called blastoderm of many invertebrates. : The term is applied especially to meroblastic ova, but is also used in reference to the mam- malian ovum; it designates the layer or layers of cells which partially or completely cover the yolk and directly participate in the formation of the embryo. The blastoderm may be defined as the stratum of cells resulting from segmenta- tion of the ovum, and not belong- ing to the yolk. We cannot en- % SIONS SoHE Oo sy eeaes of the blastoderm throughout the animal kingdom; let it suffice to point out that the structures so called are by no means always homologous. ‘Thus, in insects, segmentation is partial and produces a single layer of cells (Fig. 499), which gradually spreads over the yolk and apparently represents only the ectoderm. In vertebrates, however, the blasto- derm is more complex, and consists, in: most forms, of several layers of cells, or rather at first of a thick stratum of cells not separated into distinct layers until later stages. The typical vertebrate blasto- Fic. 499.—Section of Egg of Oniscus Murarius. (After Bobretzky.) [eT ekotsZs2 SER SL SO oo aseaeeony dues YES =m Beppe ‘Fic. 500.—Ovum of a Flounder in Transverse Vertical Section, Semidiagrammatic. 7z, Vitelline membrane; kw, segment- ing zone (Keimwall); Bl, blastoderm; s.c., segmentation cavity ; s.g., subgerminal plate; gl, oil globule of yolk. -derm can, perhaps, be best seen in the eggs of bony fishes. The disposition has been very care- fully studied by Dr. C. O. Whitman, to whom I am Vou. IT.-—1 ter into a detailed comparison, Blastoderm, Blastoderm., indebted for the accompanying semi-diagrammatic figure (Fig. 500) of the ovum and blastoderm of a flounder. The ovum is surrounded by a vitelline membrane, ¢, Fig. 501.—Kgg of Axolotl after Segmentation. Transverse section. Bl, Primitive or ectodermal blastoderm ; 8.c., segmentation cavity ; kw, (Keimwall) germinal wall; Yolk.segmented yolk. (After Bellonci.) FiG, 502.—Ovum of Rabbit ; ninety-four hours after coitus. He, External cell layer; i.m., inner mass of cells; Z, zona pellucida. resents an optical section, the lower half a surface view.) Beneden.) (The upper half rep- (After Van 1 Blastoderm, Blastoderm. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. from which it has slightly withdrawn, notably at the upper pole, where lies the thick cap of cells constituting the blastoderm, 67, in the stage represented the outer layer of cells is just becoming marked off as a distinct pellucida; He, ectoderm ; i.m., inner mass. layer, the ectoderm; underneath the blastoderm is the well-marked segmentation cavity, s.c.,; everywhere at the edge of the blastoderm lies the segmenting zone, kw., a ring of granular protoplasm with rapidly dividing nuclei; the cells resulting from these divisions are added to the edge of the blastoderm, which thus enlarges by peripheral additions as well as by the proliferation of its: component cells. The segmenting zone is prolonged in- ward, forming the floor of the segmentation cavity, or, as it is named, the subgerminal plate, s.g. This plate grows in from the periphery toward the centre; it con- tains nuclei and thins out from the edge of the blasto- derm inward. The segmenting zone, kw., is essentially the homologue of the germinal wall of the amniota, which has been described under Avea, but it is sharply bounded against the yolk, and in that respect differs from the wall in the chick, because in the latter the germinal wall merges gradually into the yolk. In the ovum of elasmobranchs (sharks, etc.), we find, at the so-called close of segmentation, that the blastoderm is a lenticular mass of cells, a little thickened at one point where the primitive streak arises later, and resting at its edge upon the very large yolk, which forms an en- circling zone of segmentation around the blastoderm; between the mass of cells and the yolk there is a cavity commonly described as the segmentation cavity. If this designation be correct, then the comparison with the teleost ovum is direct and evident. It is possible, how- ever, that the space under the blastoderm is not the true segmentation cavity, but the entodermic cavity, as Fic. 504.—Diagram of a Segmented Mammalian Ovum. Bl, Blasto- derm; s.¢., secondary cavity of the yolk; Yolk, layer of cells, rep- resenting the remnant of segmented yolk. maintained by Balfour; in other words, that the disposi- tion of parts is the same as in the birds, which we pro- ceed to describe. The birds and reptiles being very closely related, we find very close resemblances between the blastoderms in the two classes. The actual homologies of the parts have been worked out as yet only in the birds, but there eannot be much doubt that essentially the same features exist in the blastoderm of reptiles. Duval has recently shown that in birds the primitive blastoderm represents only the ectoderm, as is the case also with the amphibia; 2 (After Van Beneden.) it is separated from the underlying yolk by a distinct cavity; in birds this cavity is very small, and is overlaid by a single row of cells, the ectodermal or primitive blastoderm; the cavity is very soon obliterated by the development of cells below it, and these cells, together with the outer layer first formed, con- stitute the secondary blastoderm, which, there- fore, contains, first, the young ectoderm, and, second, a deeper-lying stratum of cells, shown by their subsequent history to be the meso- derm united with part of the entoderm; in other words, at this stage the mesoderm and entoderm are not distinct. Underneath this compound blastoderm appears a second cavity, which is not what it has been often called—the true segmentation cavity— but is entodermic, being bounded by the true entoderm above and the yolk below; the yolk, it must be remem- bered, is modified entoderm. In birds (and probably reptiles) the thick blastoderm of the teleost is represented Fig. 505.—Sections through Three Successive Stages, Ovum of the Mole, to show the changes in the inner mass,i.m. z and 2 designate the zone pellucida; Hc, subzonal cell layer, usually called ectoderm, but probably entoderm; hy, portion of the inner mass, which enters into the composition of the entoderm of later stages. (After Heape.) by only a few cells; the secondary blastoderm is another structure, consisting of two layers, and developed later. The similarity between the eggs of ganoids and of amphibians permits us to consider these two classes to- gether. At first sight the segmented ovum of an am- phibian seems very unlike that of the mesoblastic verte- brates, but if we begin by the study of parts obviously identical, I believe that we can determine the homologies of all the parts. Fig. 501 represents a transverse section of an ovum of an axolotl; the membranes of the ovum are not represented. The parts can be readily compared with those in the teleost. The blastoderm, Bi, is very large in proportion. to the whole ovum, and is composed of several layers of cells, all of which belong to the ecto- derm, and at this stage are found to be multiplying with extreme rapidity; the yolk is segmented, and accord- ingly consists of large cells. At the edge of the yolk, kw, is the zone in which cells are being added to the blasto- derm, and which is therefore the homologue of the germinal wall. The segmentation cavity, 8.c., is very large; the yolk cells bounding it inferiorly may, perhaps, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. be homologous with the nucleated subgerminal plate of teleosts. The segmentation cavity is ultimately obliter- ated, and a secondary blastoderm, including the three germ layers, is developed, as described in the article Fetus, Development of. Underneath the secondary blasto- derm arises a second distinct, or true entodermic cavity (Fig. 506). The relations are strictly comparable, there- fore, to those in the birds. The mammalia, according to the description hitherto given, offer no homology in the blastoderm stage with other vertebrates. The formation of the blastoderm is described under Segmentation. The result of segmen- tation is the so-called blastodermic vesicle, a hollow sac formed by a single layer of cells (Fig. 502, Ec.) lying close against the zona pellucida; at one pole, where the embryo is subsequently formed, lies a lenticular mass of cells, 7.m. Now, the exact relations of this cell mass have never been thoroughly studied by any one with the view of elucidating the homologies of the parts, all in- vestigators having apparently come to a tacit agreement to neglect this problem. Van Beneden, to be sure, at- tempted an interpretation by calling the outer vesicle the ectoderm, and the inner mass the invaginated entoderm, thus defining the whole as a modified gastrula. It has since been definitely settled that Van Beneden was in error in this. Our knowledge of the changes that take place in the inner cell mass is based almost wholly upon the study of various rodents (rabbits, guinea-pigs, and mice), all of whom pass, during their early development, through phases which obviously represent great modifica- tions of the normal mammalian ontogeny. In the rabbit the cells where the inner mass lies soon form three layers (Fig. 503). These are not, however, the three germ layers; for, as Rauber has shown, the two outer layers form the ectoderm, and the third inner layer forms the entoderm ; the mesoderm arises later. Here, then, we reach a definite point of comparison. The whole of this mass of cells performs the role of the secondary blastoderm in the chick, teleost, and frog; I therefore conclude that it is the mammalian blastoderm. The second point to be made is that the so-called cavity of the blastodermic vesicle is probably not the segmentation cavity, but the secondary yolk cavity, which later fuses with the notochordal canal (see Notochord) to form the definitive archenteron. Hence comes the third point, that the cellular vesicle represents not the ectoderm, as has hitherto been universally assumed, but the yolk sac hollowed out. For convenience of comparison with Figs. 500 and 502, the accompanying diagram (Fig. 504) of a mammalian - ovum after segmentation is given. According to the identification of homologies I have here hypothetically advanced, the blastoderm, Al, must include both ecto- derm above and entoderm within. If we imagine the yolk of the axolotl, Fig. 501, very much reduced, so as to form only a single layer of cells, we should have the mammalian condition, Fig. 504. It appears to me that the invagination of the inner cell mass is a general phenomenon in the development of placental mammals, and that the remarkable inversion of the germ layers in the guinea-pig is only a persistence of thisearly invagination. Itis a law which, asI pointed out several years ago, holds throughout the animal king- dom, that the result of segmentation is to produce two sets of cells: one of small-sized cells, belonging to the ectoderm, the other of larger cells, belonging to the en- toderm. In mammals also segmentation produces the two kinds of cells, but the smaller ones (ectoderm) form most of the inner cell mass which Van Beneden errone- ously called entoderm. It seems to me clear that this first invagination has nothing to do with a gastrula in- vagination. The inner cell mass gradually flattens out again in most cases, but in some mammals it remains permanently turned in (guinea-pig, arvicola, etc.). The process of the flattening out of the inner cell mass is shown in Fig. 505, which represents sections. In the mole the inner mass is nearly globular, A, and quite small in proportion to the whole vesicle. It soon becomes lens- Blastoderm, Blastoderm, shaped, B, and next separated into three layers, C, the outermost of which disappears; the middle layer becomes the ectoderm of the embryo; the innermost, part of the entoderm. These changes are discussed in the article Fetus. For the present it must be said that we have no: clear notions as to the passage of the segmented mam- malian ovum into the embryo, because we do not know yet either the history of the segmentation cavity nor the origin of the entodermic cavity. Concuiusions.—The blastoderm of (probably all) verte- brates passes through two stages: the primary blastoderm consists of ectoderm only, which is separated, except at its edges, from the yolk by the segmentation cavity; the secondary blastoderm is constituted by portions of the three primary germ layers, which overlie a second cavity Ys Fic. 506.—Egg of Axolotl, Longitudinal Section. (After Bellonci.) Bl, Primitive blastoderm; Pr, accumulation of cells, showing the commencement of the secondary blastoderm; this accumulation corresponds to the primitive streak of birds; bl, blastopore and commencement of the entodermic cavity. belonging to the entoderm and lying behind and separated from the segmentation cavity; the secondary blastoderm is the commencement of the embryo. The history of the changes in the secondary blasto- derm is given under Fetus. We will note here only the nature of the first step, which is an accumulation of cells, appearing at the posterior end of the blastoderm, and which is known in the higher vertebrates by the name of the primitive streak. It is almost the first step toward the addition of inner layers to the ectoderm or primary blastoderm, and it remains recognizable for a consider- able period at the hind region of the blastoderm or germ- inal area. Charles Sedgwick Minot. LITERATURE. a The general works of K6lliker and Balfour. Balfour and Leighton: A Renewed Study on the Germinal Layers of the Chick. Quart. Journ. of Microsc. Sci., 1883. Bellonci, G.: Blastoporo e Linea primitiva dei Vertebrati. Accad. Lineei, Roma, 3d ser., t. xix. (2 Marzo, 1884). Beneden, Ed. Van: La formation des feuillets chez le lapin. Arch. Biologie, i., 1880. Braun : Die Entwickelung des Wellenpapageies. Semper’s Arbeiten, v. Dansky u. Kostenitsch: Ueber die Entwickelung der Keimblatter. Mém. Acad. St. Petersburg, xxvii., article 13, 1880. Disse, J.: Die Entwickelung des mittleren Keimblattes in Hiihnerei. Arch. mikrosk. Anat., xv., 68. Duval, Matthias: De laformation du blastoderme dans l’ceuf d’oiseau, Ann. Sci. Nat. Zool., xviii., 1884, article 1, pp. 208, pl. i-y. Goette, Alex. : Entwickelungsgeschichte der Unke. Heape, Walter: Development of the Mole. Quart. Journ. of Microsc. Sci., 1883. (Reprinted in Sedgwick’s Studies, ii., 29.) Hensen, Victor: Beobachtungen ueber die Befruchtung und Entwicke- lung des Kaninchens und Meerschweinchens. Zeitschr. Anat. En- twickelungsges., 1875-76. Hertwig, Oskar: Die Entwickelung des mittleren Keimblattes der Wirhelthiere Jenaische Zeitschr. Nat. Wiss., 1881, 1882. His, W.: Untersuchungen ueber die erste Anlage des Wirkelthierleibes, Leipsic, 1868. His, W.: Neue Untersuchungen ueber die Bildung des Huhnerembryo. Arch. fiir anat. Physiol., Anat. Abth., 1877, 112-187, Taf. v.-vi. Hubrecht, A. A. W.: The Development of the Germinal Layers in Sorex ee Quart. Journ. of Microsc. Sci., xxxi 62, pl. XXXVi.-xlii. Mem.. 3 Blastopore, Misgharonianne REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Kupffer, O. : Sitzber. Akad. Miinchen, 1882. ; ing of a tube passing through the primitive streak, or xe : ay be ae erste pe ttees o 3 Kaninchens. Sitzber. | the thick mass of cells at the posterior end of the blasto- aturforsch. Ges., Leipsic, 1875. ts Robinson, A.: Observations upon the Development of the Segmenta- | Germ (or later embryo). Now, if from any cause the tion Cayity, etc., in Mammals. Quart. Journ. of Microse. Sci. | walls of the tube grew together, the lumen would dis- xxxiii., 869-455, pl. xxiii.-xxvii. Salensky, W.: Embryology of Accipenser (Russian). Sarazin, C. F.: Reifung und Furchung des Reptilieneier. Semper’s Arbeiten, 1883, p. 159. Schafer, E. A.: Description of a Mammalian Ovum in an Early Con- dition of Development. Proc. Roy. Soc. London, 1876. Scott and Osborn: On Some Points in the Early Development of the Common Newt. Quart. Journ. of Microsc. Sci., xix. Scott, W. B.: Embryology of Petromyzon. Strahl, Hugo: Beitrige zur Entwickelungsges. von Lacerta Agilis. Arch. f, anat. Physiol., Anat. Abth., 1882. (Cf. also 1883, 1884.) BLASTOPORE.—In the lower vertebrates, notably in the Elasmobranchiata, Ganoidea, Dipnoe, and Amphibia, there appears during the formation of the entodermic cavity a small opening at the posterior edge of the blas- toderm. This opening leads directly into the entodermic cavity, and is known as the blastopore. It persists dur- ing early embryonic life. This opening is best seen ina longitudinal section (Fig. 507). The blastoporic opening leads into a descending canal, which directly communi- cates with the posterior, or caudal, end of the entodermic space, which lies between the yolk, Vz, and the dorsal | F1G. 507.—Longitudinal Section of an Ovum of the Sturgeon After the entoderm, Ent. The appearances of the ova of the | Germ; nt, entoderm: Bl, blastopore + At, diverticulum of the lamprey, or of any amphibian, at a corresponding stage, digestive tract; Vi, yolk. (After Salensky.) are closely similar to those of Fig. 507. The blastopore is also found in reptiles, birds, and | appear, and the primitive streak would become a solid mammals, but the recognition of its occurrence in these | mass of cells. This is the condition we actually find in forms was long hindered by the fact that it doesnot exist | the mammals (Fig. 508, A). Now, since the primitive at first asa canal. The blastopore is the external open- | streak really is morphologically the thick wall of the Ec: 6 oI) PE PSTSO Woltot ce 4) Roe 0 YOON BA Oar eto a A DY XO ON O} DOS Aol 4 Oo] 6 of\t % sb Way) c) Say ad a pees IIS Soh COC RIGO re oe Peel fafa RESTS Zola Kola PS Taes LOA QO Stas Ole SOK REP COO OO NOR COA S oro toler ROTA oa aveHia BAO} wees SIV SM SOS LIAN INI SHANA LD IR IES ASTD Hats SOS ROLO) En. KOSS Fe eH alates SI BERS He EIOES Mala) ty Bea olelo/ ee Fas SESBETS Sela ites Se ANG Oy cae ane Rr aracua aN Opl> IEG) NG 0 f AO fern nga GORGE Oe DoE RG Oe SE SEA ote oS § ANG e090 EH ee an et LO REES Wie : C Um Seay ie OG Osco oad Joa EZIOXS Sone : ‘ QAvcOo. See anne Pr Colo EHP ePROS U ob 4 HES F1G. 508.—Formation of the Blastopore in Lacerta Muralis. (After Weldon.) A, B, C, longitudinal sections of three successive stages in the development of the blastoderm, made after its removal from the yolk; D, transverse section of the posterior part of a blastopore a little younger than C. Ece,ectoderm; Hn, entoderm; Pr, primitive streak; bl, blastopore ; Ch, notochord ; mes, mesoderm; Som, somatopleure ; Spl, splanchnopleure. ; REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blastopore. Blepharospasm, blastopore, the homologies are not altered by the tem- porary disappearance of the canal, especially as the canal reappears as such in later stages, at first as a pit upon the external surface (Fig. 508, B, 07); this pit soon be- comes a complete perforation (Fig. 508, C, 0/7). It is a remarkable but very common phenomenon in vertebrate development to encounter tubular organs existing temporarily as solid cell masses in the embryo. This occurs with most glands, the Wolffian duct, the vagina of man, the urethra in the penis, the nares, the meatus auditorius externus, the posterior part of the medullary canal in the axolotl, the intestines of teleosts, etc. There is, therefore, nothing specially remarkable in the temporary absence of the blastoporic lumen, and the want of an opening is not a valid argument against the homology of the amniote blastopore with that of the amphibia and similar forms. (For the relation of blastopore to the nervous system, see Newrenteric Canal.) The blastopore usually disappears by closure, and a new posterior opening, the true or permanent anus, is formed. Miss Johnson states that in the Triton the anus is the persistent blastopore, an observation of great theo- retical importance. Charles Sedgwick Minot. LITERATURE. The literature of the blastopore is very extensive. The following list cites only a few of the most important articles; those by Balfourand Bellonci may be signalized as of especial value. Balfour, F. M.: Comparative Embryology, vol. ii., chap. xi. Bellonci, Guiseppe: Blastoporo e Linea primitiva dei Vertebrati. Me- moire Accad. Lineei, Roma, ser. 3, vol. xix. His, W.: Ueber die Bildung der Haifisch-embryonen. Zeitschr. f. anat. Entw-ges., ii. Kupffer, C.: Die Gastrulation an den mesoblastischen Eiern der Wir- belthiere und die Bedeutung des Primitiy-streifen. Arch. f. anat. Physiol., Anat. Abth., 1882. : ts A.: Primitiy-streifen und Neurula der Wirbelthiere, Leipsic, ‘ Scott and Osborne: On the Early Development of the Common Newt. Quart. Journ. of Microsc. Sci., xix. Strahl, H.: Ueber die Entwickelung des Canalis myelentericus und der Allantois der Eidechse. Arch. f. anat. Physiol., Anat. Abth., 1882. Weldon, W. F. R.: Note on the Early Development of Lacerta Muralis. ate J oB8L) of Microsc. Sci. (Reprinted from Sedgwick’s Studies, At Decks 5 BLENNOSTASINE is a compound of unstated formula derived from one of the cinchona alkaloids. It is seda- tive to the central nervous system and has given much relief in hay fever, coryza, laryngitis, etc. It is not ap- plied locally, but is given by the mouth in doses of gr. i. to iv. frequently repeated. W. A. Bastedo. BLEPHAROSPASM. — DerrnitTion. —Spasmodic con- traction of the orbicularis palpebrarum muscle, tonic or clonic in character, evidenced by occlusion of the palpe- bral fissure when the entire muscle is affected, or by fibrillary contraction of a limited portion. It occurs generally as a symptomatic affection, al- though it can exist as a disease by itself. Its causes may be divided into three groups: first, affections of the eye and ear; second, affections of the nervous system; third, general diseases. The first group includes foreign bodies in the conjunctiva or cornea, in- flammations of the conjunctiva, cornea, iris and ciliary body, sympathetic irritation, ectropion, entropion, trich- iasis, heterophoria, ametropia, foreign bodies in the ex- ternal auditory canal, and otitis media. The second group comprises affections of the facial and trigeminal nerves, hysteria, and chorea. The third group includes as causes, chlorosis, perni- cious anzemia, malaria, rheumatism, and influenza. Symptoms.—It occurs in the form of a tonic or of a clonic spasm. In the tonic form the palpebral fissure is tightly closed, great force often being required to open it. It is an excessive action of the normal reflex mechan- ism, often persisting as a troublesome affliction in excess of its cause. It may be intermittent in character, com- ing on suddenly, and frequently placing the patient in great danger, when it is binocular; or continuous, some- times to sucha degree as to cause a temporary amaurosis. The latter condition is usually observed in children of three or four years of age, after relief from a very pro- tracted blepharospasm. They are unable to see large objects, and orientation is practically impossible. The pupillary reflex will be found active, strong light pain- ful, and ophthalmoscopic examination negative. The amaurosis is believed to be cortical in nature (Leber, Uthoff), owing to the absence of peripheral stimula- tion. Samelsohn has considered it to be analogous to the suppression of the image in alternating strabis- mus. Others believe it to be due to the disturbance of the intra-ocular circulation by the prolonged press- ure of the eyelids, in support of which belief they cite individual cases which have exhibited choroidal and re- tinal changes. In clonic blepharospasm there are intermittent con- tractions of the entire muscle, manifested by constant opening and closing of the palpebral fissure, or by con- tractions of a limited number of fibres, as evidenced by a slight twitching of the lids, more often of the lower lid. While the spasm may be intermittent at the outset, its continuance engenders its becoming constant and _ per- manent, and frequently the spasmodic impulse extends to neighboring muscles, CausEs.—Tonic spasm is particularly induced by foreign bodies in the conjunctiva and cornea, and by abrasions or inflammations of the conjunctiva and cornea, the phlyctenular variety particularly giving rise to it. This form of inflammation, which is seen in strumous children, is frequently accompanied by nasal disease, which may cause a persistence of the spasm long after the conjunctival and corneal disease has disappeared. The intense photophobia, and the cedema of the lids, particularly of the upper, caused by the compression of the veins of the lids by the firmly contracted muscle, render the examination of the eye extremely difficult. Fissures of the commissures and spastic ectropion or en- tropion are induced. It is believed that the blepharo- spasm in keratitis is due to direct irritation of the corneal nerves; Iwanoff having found that the cellular infiltra- tion extended along the course of the corneal nerves. It is, however, in part voluntarily induced by the patient for the purpose of relieving the photophobia. The forcible separation of the lids is often accompanied by pain, suffi- cient in some cases to induce epileptiform convulsions, and by sneezing, reflex in character, caused by the hyper- wsthesia of the retina to light. The violence cf the spasm is by no means in direct proportion to the severity of the disease of the eye, slight corneal abrasions ora small for- eign body frequently inducing the most violent tonic spasm. Iritis and cyclitis are occasionally accompanied by blepharospasm. Donders speaks of it occurring as a sympathetic neurosis in cases of irido-cyclitis. Rampol- di reports cases that were caused by the presence of for- eign bodies in the external auditory canal, Ziem a case following syringing of the cavity of the tympanum, and Berger cases accompanying suppuration of the sinuses adjacent to the orbit. Clonic blepharospasm is frequently observed in young children on their commencement of school life, either as a decided complete contraction of the muscle, or in the form of fibrillary twitchings, often difficult to discover on close inspection, though extremely annoying. In the first instance it is often a manifestation of commencing chorea, the children presenting a marked anemia. The fibrillary form is generally due to uncorrected errors of refraction. Adults presenting heterophoria and ametro- pia, particularly hypermetropic astigmatism, are prone to this variety. Affections of the facial nerve through traumatism or cerebral lesions may give rise to blepharospasm, though it is more often a reflex phenomenon due to a local or distal irritation of one of the branches of the trigeminus. Supra- and infra-orbital neuralgia, caries of the teeth or maxille, ulcerations of the tongue, mouth, and palate, and chronic affections of the lachrymal canal may be : 5 Blindness. Blindness, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. cited as causes of such irritation. Saemisch has men- tioned cases which were caused by the imprisonment of sensitive nerve filaments in cicatrices. In neuralgia of the different branches of the fifth nerve sensitive points can be found, pressure upon which will often arrest the spasm. ‘These spots may be situated at the point of exit of the nerves from their foramina, or may be located some distance from the affected muscle, as at the back of the neck, over the spines of the vertebre. Romberg found that pressure upon the facial nerve at its exit from the stylo-mastoid foramen would arrest the spasm in some cases. The patient often discovers where these pressure points are situated, and will avail himself of this knowledge to obtain relief. Pressure upon certain parts of the body has been known to bring on blepharo- spasm, as in the case reported by Zehender, in which pressure in the region of the first cervical vertebra in- duced it. Cases like this one are undoubtedly of hys- terical origin. Indeed, not a few cases of blepharospasm are of hysterical nature. The spasm may be caused primarily, in these subjects, by traumatism, by a carious tooth, or by a foreign body in the conjunctiva, cornea, auditory canal, etc. Its continuation after removal of the cause and disappearance of all irritation would indi- cate its hysterical character. It is usually binocular, tonic in character, and rarely preceded by clonic move- ments. Its disappearance is as sudden as its invasion, and its duration varies greatly. Dr. Charles Laségue cites a case of monocular hysterical blepharospasm, caused by traumatism, which lasted four months, while the immediate effects of the traumatism lasted but twenty- four hours. A constant twitching of the upper lids re- peated about twice a second is characteristic of hysteria, and is believed by Knies to be due, like nystagmus, to a weakening of the motor cortical innervation of the mus- cles. Anesthesia of the palpebral skin may be noticed as an accompanying symptom, as shown by Gilles de la Tourette. In anzemic and nervous children blepharo- spasm occurs as the commencement of general chorea. The habit-chorea (Weir Mitchell), which commences in childhood, ceases after a few months or years, although it occasionally goes on to middle life. When it com- mences in middle life it is generally permanent. It is more common in females, following some impairment of the general health, fright, injury or overwork, and in boys, as the result of masturbation. Imitation can bring it on and observation increases it. Refractive errors, follicular conjunctivitis, and blepharitis are also found as frequent causes. It is oftenassociated with symptoms of hysteria in young women, making it difficult to de- termine to which disease the spasm properly belongs. Anzemic women occasionally present a clonic monocular spasm, due to the general debility induced by uterine and ovarian disease. Proenosis.—The prognosis in blepharospasm is un- certain except where it is due to hysteria, traumatism, conjunctival or corneal disease. Prolonged contraction may involve serious consequences to the eye, through the pressure of the lids causing definite lesions of the choroid or retina. TREATMENT.—The treatment of blepharospasm re- solves itself into treatment of its causative conditions. A careful search should be made for foreign bodies in the conjunctiva, cornea, nose, andear. If conjunctivitis and keratitis, particularly of the phlyctenular variety, are present, they should be carefully treated. Cocaine, while often of value in relieving blepharospasm and rendering the examination of the eye easier, should be avoided in cases in which there are corneal ulcerations; holocain should be used instead, in one-per-cent. solu- tion. The dilatation of the pupil with consequent in- crease of the photophobia, owing to the hyperesthesia of the retina and the softening of the corneal epithelium following the use of the cocaine, are avoided by the sub- stitution of the holocain, the latter being primarily an anesthetic and secondarily an antiseptic. In cases in which the spasm persists after the conjunctival and cor- neal disease has been cured, forcible opening of the pal- 6 pebral fissure, during chloroformization, with canthotomy if necessary, and the dropping of iced water on the ex- posed eyeball at half-hour intervals, will usually suffice to produce a cure. These children should not be allowed to remain in the dark, nor should dark glasses be given. Fissures of the canthi may be touched with a crystal of sulphate of copper or with nitrate of silver, and the ac- companying nasal disease, when present, should be treated. In cases in which eserin is seemingly indicated it may be found that the spasm is increased by its use, eserin having been known to cause violent blepharospasm. De Wecker recommends its use as a curative agent, be- lieving that it diminishes the tendency to reflex trans- missions. Errors of refraction must be corrected under atropinization, and muscular errors should be carefully remedied. In cases due to irritation of some branch of the fifth nerve, careful search must be made for pressure points. Hypodermic injections of morphine, in doses of from gr. 7 to 4, may be made at these points. Conium, in the form of the fluid extract, may be given in doses of ten drops, from three to six times daily, until the physiological effects of the drug are shown. The extract of conium may at the same time be used externally in the form of an ointment. Gelsemium may be found of bene- fit in the cases of true tic doloureux. Galvanism, used after the method of Remak, the negative pole being ap- plied over the muscle and the positive over the fifth cervical vertebra, is sometimes efficacious. The careful examination of the mouth and teeth by a competent dentist should always be insisted on, the patient often being unaware of the presence of dental or buccal trouble. Other remedies having failed, and pressure upon sensitive points having been found to give relief, division of the offending nerve may be prac- tised. This operation was first performed by von Graefe in a case following the lodgment of a foreign body in the folds of the conjunctiva. The nerve divided was the supra-orbital, and success followed the operation. The supra- and infra-orbital nerves should be divided at their exit from their respective foramina, the temporal branch of the malar in the temporal fossa, and the in- ferior dental in the mouth. The nerve should be com- pletely cut through; in fact, some authorities think that a better result is obtainable by the excision of 1 to 2 cm. of the nerve. The relief given by section of the nerves is not always permanent, the spasm after a short period returning and being accompanied by the development of new pressure points. This is particularly true in senile blepharospasm. Excision of a portion of the nerve is productive of more lasting relief, although it gives rise to a prolonged anzesthesia of the region supplied by the nerve. Stretching of the nerves has been advocated by Panas. Dieffenbach practised subcutaneous division of the orbicularis muscle, but without much success. Treatment of hysterical blepharospasm is decidedly unsatisfactory. Tonics, sea bathing, the use of the ap- pliance devised by Mathewson and used with success by Strawbridge, and the application of the Charcot magnet with suggestion, may be tried. The device of Mathew- son consists of a rubber band fastened to the upper lid below, and to the forehead above. The constant traction eventually overcomes the resistance offered by the muscle. Arsenic given internally, or hypodermically, as suggested by Weir Mitchell, appears to be the most efficacious remedy in the cases of habit-chorea. C. Cole Bradley. BLINDNESS.—(Lat., Cecitas; Ger., Blindheit; Fr., Aveuglement.) Amaurosis is sometimes used synony- mously with blindness, and in selected cases—the cause of which is obscure, or is located in the nervous apparatus —this is admissible, with the same limitations that apply to blindness. Blindness is a misleading term, being a symptom only, and should not be used in scientific language (except in a generic sense) without a qualify- ing phrase which describes the condition upon which it depends—as blindness from optic-nerve atrophy. PrUussifivesgerisn: « SS ENOLWAY, . 060s ve ssices.0 Veer OL: Detachment of retina ....... Rbehanttia nicicsiustes ocecee 4.140 CH etre SS at eB ie oe a atantencc Rn ontelcor 8.97 Idiopathic optic-nerve atrophy.........+.++6+ Facardpape 7.751 Tumors of the eye and its surroundings.......... Sonus: Popes MERC ITCRA LG Mavis alreivsveiscle lic mie’s.¢ cceis | 4.9 0/0 00,0 dns eoteaiieen? (8,506 0.— Acquired blindness—(b) Injuries. Direct injury of the eye...............006 piateretalen eres 4.034 Unsuccessful operations ......... ol olesaefoteiovels: eoaial b's orale cieveie 1.938 ALICE OF NCA foo vs es wes seOcin ed ateebeyondeeor. tt Traumatic sympathetic ophthalmia...... Ss SENAO IO SOES 4.509 D.— Acquired blindness—(c) The eye disease being in consequence of disease of the body. Diseases of the eye from syphilis..............- Heche AT Gonorrhoeal CONJUNCTIVITIS... 6... 6. eee eee eee SOO ES OLE .910 Scrofulous diseases of the eye.........-.. eel stetaate ineces .039 Trido-choroiditis with meningitis . Atrophy of optic nerve, cerebral. SOL ir Sa sphagoo podon poppers ne Mrs ad “of neuritis following hama- TEMMeSIS eect esean iver 22000 cs ae eo ‘* “after vomiting, not blood..... 07 Atrophy from hemorrhage from piles. ...--...eeseesee., -039 . after facial erysipelas .-.<..s.ccecsercces Soon PAE MEENTICL INSAMIGV ctivrcinies sisiviiercioitie.c(s\se'a vee 0151s meaetle .039 Bs Bees ODLIGD SY aiecs trace sete 5) sreveislere Suicisie Ccerasee as 158 * Sem CLUBONLOLV ns actiiee sire teeeretets caine Seousd. eifty Retinitis nephritica.......... ...... Santncoedencanonoton -ale;s" Diseases of the eye from typhus ...-.....- aatioue eisv ican oe We os Sipe MCASIES. 46 < Y rs usually sought ss for. \d Z pe ant 4 Hematoporphy- lm Sr oe rin (Cs2Hs6NiO¢) of) ny z= 7 De is obtained by the < rare pats of +f action of strong Cee) 7] sulphuric acid on ie “ hematin. It is Pee Ok I oe characterized by the absence of iron. Hemochromogen is obtained by decomposing hemo- globin with acids or alkalies in the absence of oxygen. It crystallizes and has a characteristic spectrum. Hematoidin (C:6HisN2Os). This name was applied by Virchow to a crystalline substance found in old blood clots, formed, without doubt, from the hemoglobin of the clotted blood. It has been shown to be identical with one of the bile pigments—bilirubin. It shows no definite absorption band in its spectrum, but causes a general absorption of the ultra - violet, violet, and blue rays. Bile and Urinary Pig- ments. —Heemoglobin is con- sidered to be the parent sub- stance of the urinary as well as of the bile pigments. “Laky Buioop” is the term applied to the blood when the hemoglobin has escaped from the corpuscles and becomes dissolved in the plasma. ‘Normal blood with the hemoglobin enclosed in the corpuscles is opaque even in a very thin layer, whereas laky blood in thin layers is transparent. A sufficient disturbance of equilibrium or osmotic re- lations between the corpuscles and surrounding medium will cause this escape of the hemoglobin. Blood may be made laky by the addition of distilled water, acids, alkalies, heat, ether, chloroform, bile or bile salts, by 29 Fig. 528.—Hzemin Crystals Magnified. (Preyer.) Fig. 524.—Heematoidin Crystals. Blood. Blood, alternate freezing and thawing, by the serum from the blood of another animal, electricity, and numerous other methods. Isorontc SOLUTIONS, as applied to the blood, refer to liquids containing soluble substances with an attraction for water, in quantities sufficient to prevent the imbibi- tion of water by the red corpuscles. The liquid must be concentrated enough to prevent the absorption of water by the corpuscle. ds, and later a complete | reunion of the two a ll ul Dorp gus en ae Fig. 534.—Small Vein in Mesendane Lew to his classification cocytes sending off a process clear of there are three main granules (a and b). (After Craig.) types: 1. A small, colorless and immobile leucocyte, evidently correspond- ing to the lymphocyte of other writers. 2. The second type consists of five forms of leucocytes, all of which are characterized by the power of displacing a larger or smaller amount of their substance and possess a greater or less degree of mobility. They differ in respect to their granularity. 8. Two forms, one very granular, immo- bile, and deformed; the other showing beginning signs of disintegration. The above types represent the periods of development and decay; the second type representing the active life of the corpuscle. In determining the effect of temperature upon the leucocytes of the human blood, Maurel found that at about 25° C. (77° F.) movements as evidenced by dis- placement of their cellular substance were generally manifested. Between 25° and 16° C. these displace- ments were very feeble, and at 16° they ceased. If this temperature, however, was of short duration and gradu- ally raised the movements would return. At 14° C. (57° F.) life disappeared from the corpuscles completely. ‘He concludes that a temperature of at least 25° is re- quired to cause , Satisfactory move- ments in the cells and that the above temperature is es- sential for the oc- currence of diape- desis. Between 25° and 82° C. the displacement of substance is very slight. From 32° to 389° C. the movements are very marked. From 39° C. (102° F.) to 48° C. (109° F.) the maximum degree of activity occurs. Above 44° ©. (111° F.) the life of the corpuscle is very quickly menaced, and at 45° C. (118° F.) the leucocyte takes on a spherical form and dies in a short time. The temperature as usually taken (axilla, etc.) is supposed to be one to two degrees lower than the internal temperature (liver, etc.), so that from | the above figures, the greatest activity of the leucocytes in the human body takes place at the normal and during a febrile state of medium intensity. In animals of dif- Blood Capillary. i] i] a bee a e Fig. 535.—Diagrammatic Representation of the Manner in Which a Leucocyte Traverses the Wall of a Capillary Blood-Vessel. (After Craig.) a, Leucocyte before penetrating ; b, leucocyte sending off process and gran- ules beginning to withdraw to farther end of cell; ¢, leucocyte partly through wall, granules at upper end of cell; d granules passing through the wall; e, granules ar- ranged in the portion of the leucocyte far- thest from vessel; f, leucocyte, after pene- tration, resuming its original condition; g, leucocyte swept from wall, showing reten- tion of the clear penetrating process. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ferent species in which the temperature is normally different from that of man, the variations in the ac- tivity of the leucocytes are correlated with the tempera- ‘ture of that species of animal. In addition to studying the power of resistance ex- hibited by the leucocytes with respect to extremes of temperature, Maurel has also investigated their power of resistance against certain physical and chemical agents and drugs. As with temperature, the leucocytes of dif- ferent species will react differently toward the agents just mentioned. He found that while human leucocytes are sensitive to cocaine and very much so to atropine, those of the rabbit were only one-third as sensitive to cocaine and not at all to atropine. The leucocytes of the frog. will absorb certain pathogenic bacteria with im- punity, while those of the rabbit and man will not absorb them, but are rapidly killed. Horbaczewski has called attention to the fact that uric acid originates chiefly from the nuclein of disin- tegrated leucocytes, and the greater the number of leu- cocytes in the blood the greater is the destruction of the same, and hence the elimination of uric acid is corre- spondingly increased. Observations on the elimination of uric acid harmonize with this theory. In leukemia, where there is an abnormally large number of leucocytes, the elimination of uric acid is greatly increased. Those drugs which increase the number of leucocytes also ia- crease, in general, the elimination of uric acid. Origin of Leucocytes.—It is evident that leucocytes are formed largely in lymph glands, from the fact that the lymph leaving such glands is much richer in cor- puscles than the lymph coming to the glands. The fact that lymph coming to the glands contains leucocytes indicates that, although some of them may get into the lymph by diapedesis, other parts are also concerned in their production, ¢.g., diffuse adenoid tissue, or special collections of it such as the tonsils, Peyer’s patches, and the solitary follicles in the intestine, and the splenic cor- puscles. To a small extent the white corpuscles may multiply in the blood by karyokinesis. The latter method may perhaps occur more generally in the so- called cold-blooded animals than in mammals. The fate of the leucocytes is much less easy to ascer- tain than that of the red corpuscles from the fact that the former contain no such pigment as hemoglobin or other substance that would assist in following the path of their destruction. It is not improbable that some of the leucocytes undergo disintegration in the blood itself and that their constituents aid in maintaining a proper proteid equilibrium. It has been shown by the work of Miss Claypole and of Berry that many of the leucocytes are undoubtedly destroyed in the spleen, and it is not at all unlikely that other localities are also involved in this process. That they are constantly breaking down is certain, for they are constantly being produced. Bioop PLATELETS OR PLAQuUES.—The Blutpldttchen (Bizzozero) or heematoblasts (Hayem) are small, circular, sometimes irregular bodies appearing nearly homogene- ous in structure and varying in size (0.5 to 5.5 microns). They average about 3 microns in diameter and are al- ways smaller than the red corpuscles. Hayem’s view that they. are heematoblasts or precursors of the red cor- puscles is now considered erroneous. Their number in the blood has been variously estimated from 180,000 to over 600,000 per cubic millimetre. Taking 400,000 as the average number, they would be forty times as numerous as the leucocytes and about one-twelfth as numerous as the red corpuscles. Although there has been a great amount of histological research upon the platelets, very little is known of their function or chemical composition. It is generally believed that they are not independent cells. In drawn blood they disin- tegrate almost immediately; this fact prevented their discovery foralong time after the blood had been studied microscopically. To study them, the blood must be drawn at once into some fixing solution (osmic acid, etc.). They can be seen, however, in capillary blood- vessels which have just been removed from animals, in Vou. II.—3 Blood, Blood, which the blood is still fluid and the constituents there- fore still alive. They have not been found in lymph. According to Léwit they consist chiefly of a globulin and play an important part in fibrin formation (coagu- lation). Lilienfeld from a chemical standpoint considers that they consist of nucleo-proteid, a substance like that obtained from the nuclei of leucocytes. From this ground, some take the view that the platelets are de- au? ere Sa waa er a 1minute ~* bie ‘& Anns. 10 mins. AN Fig. 536.—Figures of a Leucocyte Undergoing Division (Amphibia). (After Claypole.) rived from the nuclei of the leucocytes, and that when the multinucleated forms go to pieces the fragments of the nuclei persist for a longer or shorter time in the blood as platelets and are eventually dissolved in the plasma. The special function of the platelets, beyond that of assisting in coagulation, still remains to be dis- covered. Frsprin.— When blood coagulates there separates from it an albuminous substance, which is nearly insoluble. This substance is fibrin, and remains in the clot. If co- agulation is prevented by whipping the blood, the fibrin adheres to the rods of the whip in the form of elastic threads or fibrin masses. These may be .washed free from the adhering corpuscles by using a stream of water. While wet the fibrin has a white, stringy appearance, later drying into an irregular mass. The threads which compose fibrin, as seen in a microscopic preparation of blood, interlace with one another and form a fine net- work, which entangles the blood corpuscles in its meshes. These have a strong tendency to retract, and explain why a clot shrinks and squeezes out the serum from its interior. Fibrin exists in the lymph as well as in the blood. 33 Blood, Blood, The blood of mammals and of amphibia, as shown by Gage, exhibit an interesting difference in regard to the fineness of the constituent threads. In the frog (Necturus and Cryptobranchus) the threads are relatively very much finer than those in mammals, requiring careful observa- A AVES TAK, \ CA, ar a x] ae FIG. 537.—Fibrin Network from the Blood of the Frog. a, Granular mass of fibrin; gf, isolated granules of fibrin; (After Renaut.) = SS; = = EoD fe let , de- formed leucocyte. tion with a one-twelfth-inch oil-immersion objective. OUH> CO 1 ag 3 Fig. 540.—-1, Bausch and Lomb, 7 inch, No. 1 cover slip; 2, Bausch and Lomb, extra thin slide; 3, blood sticker, two views—a, point in sheath for carrying instrument in pocket; ), point in place ready for use; 4, clamp forceps, two views—side view, showing close apposition of tip of limbs; front view, showing proper extent of grasp of cover slip (1); 5, open forceps, two views—side view, Instruments made by F. Arnold & Son, instrument makers, Baltimore, Md.) front view. (Note: therein mentioned. They are, however, accurate for reference for all blood changes in those diseases. For fuil instruction upon the following not included in this article the reader is referred to other articles in this HANDBOOK, such as those on Anwmia, Leucocytosis, Blood Stains (Medico-Legal Consideration), Histological Tech- nique, Malaria, Typhoid Fever, etc. ] I. FresH-BLooD SPECIMEN. In preparing the blood for microscopic examination, however so careful the technique employed, the oper- ator is subjecting one of the most delicate tissues of the body to very rough and unnatural surroundings. When one realizes the exquisite smoothness of the in- tima of the blood-vessels, the wonderfully regulated temperature of the body, the delicate structure of the red cell, the even more delicate structure of the plate which without most careful preservation is entirely de- stroyed a few seconds after exposure to the air—when one realizes all these factors against observation of the 38 . blood as it appears in the circulation, it is a surprise that any technique is delicate enough. This realization at the same time emphasizes the importance of observing every precaution which experience has shown to be necessary in the preparation of the blood specimen which shall be, outside of the body, as nearly as possible repre- sentative of the blood as it appears in the circulation. The object then of apparatus and technique is to pro- duce surroundings as nearly like those normal to the blood in circulation as possible. To accomplish this we must observe the following: (1) Absolute cleanliness and freedom from moisture; (2) avoid chilling the blood; (8) avoid exposure to air; (4) avoid rough treatment of the drops and consequently of the constituents thereof— the corpuscles. The Cover Slip.—Absolute Cleanliness. The cover slip should be the thinnest made and square in shape (Bausch and Lomb, No. 1, gin. (see Fig. 540, 1). The thicker cover slips are often too thick for the focus of the one-twelfth immersion lens, and not infre- quently specimens from inter- esting cases at a distance from the laboratory and received by mail cannot be examined accu- rately owing to this annoying condition. It is a good rule for those engaged in blood work not to have the thicker cover slips under any circum- stance. The Slide.—For the same rea- son the thin slide should be em- ployed (see Fig. 540, 2). Two jars, one containing thick slides for urine work, and thin for blood work, will be found a convenient arrangement. These cover slips and _ slides should be kept in fifty per cent. alcohol. When to be used they should be rubbed with a bit of clean silk, or some fabric free from lint specks. They should be rubbed quite free of any cloudiness or dust and then dried. This last can be done either by pouring a little ether over the glass and rubbing again or by heating gently over aflame. The cleaned slip and slide should now be laid upon a sheet of clean paper. The following instruments, as first recommended by W. 8. Thayer of the Johns Hopkins University, will be found es- sential : The clamp forceps are so made that the extreme tips of the limbs meet before any other portion, and this enables one to take a small but firm grasp of the cover slip (see Fig. 540, 4, 0). The clamp, moreover, enables the operator to give his whole attention to following the technique, as given below, without being diverted by keeping a grasp on the cover slips. By placing the cover slip in the clamp forceps it can be kept free from dust and moisture from the fingers and will be ready for use. The lobe of the ear is by far the best locality for puncture. For the following reasons: (1) Less sensi- tive; (2) the act of puncture and the blood are not seen by the patient, important with nervous people and chil- dren; (8) pressure, if necessary, is more readily exerted and produces better results; (4) the skin in this locality is softer and cleaner; (5) there is less likelihood of sub- sequent infection. The lobe of the ear is then gently wiped (not rubbed, as this produces hyperemia) with a silk rag moistened in alcohol and the skin is then dried with ether. If ether is REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood, Blood, not to be had, it is better either to dilute the alcohol three or four times or to use distilled water. Alcohol if left on the skin hardens the blood and so injures the speci- men. The Sticker.—The sticker is now employed (see Fig. 540, 3). This is extremely sharp and is diamond shaped on cross section; the object being to produce a similarly shaped wound, and therefore one which will the more readily bleed. A surgical needle may be used, but an ordinary needle or pin is very unsatisfactory. If, how- ever, one or the other of the latter is all that can be ob- tained, it should be boiled. When cleanliness is observed, it is only necessary to dip the end of the sticker into alco- hol before and after making the puncture. The most dependent portion of the lobe of the ear is now punctured by a stabbing motion, the sticker being held as in illustration (Fig. 541). The first drop is wiped away, the second allowed to flow, if possible, without pressure being made upon the skin. If pressure be neces- sary it should be exerted far away from point of punc- ture, so that this artificial means shall not alter the char- acter of the drop taken for examination. Avoid Chilling the Blood. It must be remembered that the blood is being submitted to a lower temperature than normal in this proceeding, and in order to avoid chilling the blood it is a good plan to warm the slide and cover slip over a spirit lamp, or to have another person briskly rub the slide with a bit of silk. The clamp forceps holding the cover slip (see Fig. 540, Fig. 541.—Method of Making Puncture for Fresh and Dried Speci- mens of Blood. Shows position of hands and wrist just as puncture is about to be made 4) are now brought toward the ear, and the under sur- face of the cover slip—and therefore that free from dust —is made to touch the apex of the drop of blood, not the skin of the ear (Fig. 542). The cover slip is at once carried to the warmed slide and gently lowered. Avoid Rough Treatment. The cover slip should not be dropped on the slide. One side of the cover slip should be rested on the slide and gently lowered until the limb of the forceps touches the slide. The forceps are then opened and by a quick jerk drawn away (see Fig. 548). Avoid Exposure to Air. It must be remembered also that the air isa destructive medium to the blood, and the time occupied for these steps must be as brief as possible. The cover settles and the good blood specimen spreads equally in all directions, being for the most part circular with fine spicules at the periphery of the circle. The drop should not be so large as to reach the margin of the cover slip when on the slide. This technique may be summarized as follows: 1. Apparatus. Thin slide, square thin cover slip, sticker and clamp forceps. Alcohol, ether, spirit lamp, silk cloth. 2. Absolutely clean point of puncture and apparatus. Fig. 542.—Method of Taking Drop of Blood for Fresh and Dried Specimens of Blood. Shows how to hold forceps and ear, how to steady hands, and the extent of grasp of cover slip by clamp forceps. 83. Seize cover slip in clamp forceps and place near at hand. 4. Light puncture of the most dependent portion of lobe of ear. 5. Warm slide and cover slip gently over spirit lamp; or have another person rub slide briskly with silk cloth. 6. Wipe away drop from point of puncture. (If press- ure is required, exert it faraway from point of puncture.) 7. Touch apex of drop with under sur- face and centre of cover slip. 8. Place cover slip promptly but gently on slide. Fig. 543.—Correct Position of Hand in Holding Clamp Forceps. Cover slip resting on slide. The illustration represents the position just before the forceps are opened and jerked away. Characteristics of a Good Fresh- Blood Specimen.—Gross : 1. Blood does not reach margin of cover slip. 2. Is of 39 Blood, Blood. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. a circular shape with fine spiculated appearance at periphery. 3. Is thinner in the centre than at margin of specimen. (See Plate XIII., Fig. 1.) Microscopic: 1. Corpuscles each lying separate with some little space between—not in rouleaux. 2. Majority of corpuscles stationary. 8. Each corpuscle circular— not erenated. (See Plate XIII., Fig. 6.) Poikilocytosis is of course pathologic and cannot be avoided; crenation is not, however, and is usually due to faulty technique. (See Plate XIII., Figs. 3 and 5.) Characteristics of a Poor Fresh-Biood Specimen, and Such as Condemn It for Examination.—Gross: 1. Blood thick and oozing out from under cover slip indicates that too much blood has been taken. 2. Irregular shape indicates either that too much blood has been taken, or that dust has been on the slip or slide, or that the blood has been chilled. 3. Thick at one point and partially spread at another indicates dust or moisture. 4. Lump of blood—no spreading—indicates general uncleanliness. Microscopic: 1. Structureless masses. 2. Abundance of rouleaux. 38. Much crenation. 4. Corpuscles closely placed, giving tiled-floor appearance. 5. Corpuscles rapidly floating about specimen. 6. Corpuscles ragged and mutilated. 7. White corpuscles broken into granular collections. (See Plate XIII., Figs. 3 and 5 W nat can be Learned from Fresh Specimens of Blood.— When the precautions laid down in the foregoing have been observed, the following objects may be distinguished: 1. The Red Blood “Corpuscles—non- nucleated in the normal. Size—7u. (Note: « = micron = s34,, 0ofaninch. Itis well to become familiar with the size of the red cell, and to use it as a unit of measurement when speaking of oth- er bodies, as twice, thrice, etc., the size of the red cell.) Shape—biconcave discs. Color—pale yellow. Character—elastic. Tend to form rouleaux. Become crenated. May contain bright round spots termed “artifacts.” The adjective artifactitious, or simply factitious, might be applied to the last three conditions, as they are the re- sult of manipulation. 2. Microcytes or Macrocytes. \ 3. Poikilocytes. eee ‘ajjq_ § Normoblasts. 4. Nucleated Red Cells. } Gigantoblasts. 5. Lake-like Areas with irregular shape and mar- [ gin in the red cells, due to deficiency of hemoglobin, | | Conditions due to faulty technique. “BIULBUB UT termed by Maragliano “degeneration areas, * called also vacuoles. 6. Shadow Corpuscles, described first by Norris, are seen in the blood of anzemia from toxicagents and burns. These are red cells deprived of hemoglobin. They can be arti- ficially produced by adding water to the blood specimen. ells. 7. Small Mononuclear or Small Lymphocytes. 8. Large Mononuclear or Large Lymphocytes. 9. Transitional Mononuclear or Transitional Lympho- cytes. 10. Polynuclear Leucocytes. 11. Eosinophiles. 12. Myelocytes in leukeemia. detected in the fresh specimen. ) An approximate idea of an increase in the white cells as a whole, and one or other variety of these individually, can be had from the fresh specimen. More than four or five white cells in a well-spread field with a one-twelfth im- mersion lens may be taken to indicate a leucocytosis. In lymphatic leukeemia the increase in the small mononuclear leucocytes is readily appreciated; so also the presence of the cells normally found in the bone marrow, as the myelo- cytes, can be detected in the fresh specimen in cases of spleno-medullary leukemia. In inflammatory ieucocyto- sis the increase in the polynuclear leucocytes can be noted, The increase in the eosinophiles, so important a diagnostic sign in trichinosis, etc., can-also be detected. (The Mastcells cannot be 40 13. The Plate * and the Plaque—non-nucleated. Size—One-seventh the size of the red cell (1). Shape—irregular. . Color—colorless. Not visible normally. By placing a drop of Hayem’s or Pacini’s solution + over the point of puncture (the finger must be used for this purpose) and allowing the blood to mingle with this preservative fluid the plates may be seen. The cover slip is applied to the drop in the same way as when ° taking a fresh specimen. We have no systematic work upon the significance of the presence of these bodies. The writer has noted them in great numbers (without the use of a preservative fluid) in the blood of pneumonia cases, in a case of grave anemia secondary to malaria, and in a case of Hodgkin’s disease. The work of Osler, Bizzozero, Schimmelbusch, Welch, and Eberth has been more to prove that these bodies are separate corpuscular elements than to explain their as- sociation with disease. An exception to this statement should be made in favor of- Welch’s work, which goes to show that these bodies are the active agents in the formation of the white thrombus; but even this has not, as yet, been of any clinical value. 14. Fibrin does not, normally, appear for some time in a well-taken fresh specimen. Its presence shortly after taking the specimen is therefore of pathological signifi- cance. We have not been able as yet, however, to at- tach any diagnostic value to this condition. 15. Blood Dust (hemokoniosis, literally, blood full of dust, of Miiller) can be seen as floating particles about one-twentieth or one-thirtieth the size of the red cell. No satisfactory explanation of the significance of these particles has as yet been given. 16. The Tertian and Quartan Malarial Parasite in all its stages of development, and many of the stages of the Astivo-autumnal Malarial Parasite, may be seen with the one-twelfth oil-immersion lens. 17. The Filaria Sanguinis Hominis may be seen with the 7 or 9 Leitz lens. 18. Spirochaéte of Relapsing Fever may be seen with the 7 or 9 Leitz lens. All this information is to be had by the simple pro-. cedure of taking, in the way described, a specimen of blood. All these points will be found grouped in the table at the end of this article. Having ascertained, then, from the fresh specimen that there is a decrease in the number of red cells, or an in- crease in the number of white cells, it becomes necessary to determine this decrease and increase definitely, for which purpose additional instruments are required. II. BLoop-CoRPuscLE CoUNTING. History.—It is only of late years that the methods of enumerating the blood corpuscles have been simplified so as to be clinically applicable, the complicated apparatus heretofore used having had place in works on physiology only. It is therefore of value to trace the development of our present simple apparatus from its complicated be- ginnings. When we look over all the methods employed to accomplish this last, we find that investigators have endeavored to construct apparatus along three separate lines, as follows: 1. Actual enumeration. 2. Centrifug- alizing and estimating cells according to amount of sedi- ment. 95. Color changes and opacity due to decrease in number of cells. This will therefore be, not a history of blood counting in chronological order, but rather the record of the devel- opment of apparatus along these three lines. * The term plate is here used to refer to the corpuscles; plaque to the aggregation of these plates. Platelet, a term synonymous with plate, is best discarded. + Hayem’s Solution. Pacini’s Solution. Bichloride of mereury.... 0.5 | Bichloride of mercury...... 2. Sodium sulphate ......... 5. | Sodium chloride........... 4, Sodium chloride.......... 15") GY Cerin dis ons ohse oe 26. Distilled water........... OL! Distilled waterwnescie ese 226. ' ha $e : ae-* rs ~ Cs CY EXPLANATION OF . w . 4 TF 0 > 4, ee. G ~~ a a 7 tf . « 7 . * . o . oF 2 a tS 4 = ~ = ~ “ = 4 Ae fatd ie ais . * = PLATE EXPLANATION OF PLATE XIII. (DRAWN By Dr. E. DUNNING.) Fic. 1.—Gross appearance of well-taken fresh-blood specimen. - | gee p, 89: Characteristics of a Good Fresh-Blood Speci- men. Fie. 6.—Microscopic appearance of well-taken fresh-blood speci- men. Fie. 3.—Microscopic appearance of poorly taken fresh-blood specimen. See p. 40: Characteristics of a Poor Fresh-Blood Spect- Fie. 5.—Microscopic appearance of poorly taken fresh-blood men. specimen. Fig. 2.—Microscopic appearance of the Thoma-Zeiss count- ing stage with normal biood diluted with Toison solution. Red cells unstained ; white cells stained blue. This is with the low-power objective (8 Leitz) which takes in all sixteen \ See p. 45. squares (see Fig. 555, p. 44), but does not magnify the cell as much as the higher power (see Plate XIII., Fig. 4), and which therefore greatly increases the task of counting. J Fic. 4.—Same as Fig. 2, Plate XIII, except that the blood is } that of leukeemia (120,000 leucocytes to the cubic millimetre), | and the objective is of high power (7 or 9 Leitz). This } See p. 45. takes in only one-sixteenth of the entire field, but it renders | the corpuscles much more readily distinguishable. REFERENCE HANDBOOK OF THE PLATE XIll MEDICAL SCIENCES Fla. 3. Kies. FIG. 6, HUMAN BLOOD REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. .1. ActuaL ENUMERATION OF BLoop CoRPUSCLES.— Vierordt was among the first actually to enumerate the red blood cells; and though his apparatus was most Blood, Blood, divided into fractions of a cubic millimetre, as seen in the illustration. The microscope is adjusted so as to mag- nify the corpuscles as they lie in the artificial capillary (see Fig. 546), and their number ascertained for a fractional part of this capillary as marked on the glass plate. According to the fraction of a cubic millimetre which that portion selected to count represents, the number counted is multiplied. Suppose one counts the corpuscles in Fig. 544.—Potain’s Mixer. crude and his method most complicated, yet his results have been abundantly confirmed by subsequent observers working with varied styles of apparatus. Vierordt’s fig- ures were, 5,174,000 red blood cells per cubic millimetre. Vierordt diluted with a fixed quantity of sugar solution a cubic millimetre of blood and then spread this upon a slide. By means, of a micrometer he counted every cor- puscle. For one enumeration it took an entire week. The result of this work was to establish the following: (1) A known quantity of blood must be taken, that quantity being the amount contained in a cubic milli- metre. (2) A known dilution. (3) A cubic millimetre of normal blood contains 5,174,000 red cells. At this time, Kélliker, after declaring that “owing to the difficulty of the subject” the most careful estimates can “only be described as approximate,” adds: “One method only can be successful, consisting in the direct enumeration of the globules in accurately determined quantities of blood.” Welker adds the next improve- ments (1) in using a stage micrometer, and (2) in counting the corpuscles in a fraction of a large dilution and multi- plying the result of this count by the figures required to make the whole cubic millimetre. Potain’s mélangeur or mixer afforded the first means of accurately diluting the blood. This was nothing else in principle, but of cruder make, than the mixer now em- ployed in the Thoma and Zeiss blood-counting apparatus. Fig. 544 shows this mixer. Potain’s mixer was divided precisely as is the Thoma- Zeiss mixer, into a dilated and a capillary portion, the capillary portion being exactly z+, part of the whole. The dilated portion of the Potain mixer contained the lit- (} = 500/e5i Fig. 545.—Malassez’ Artificial Capillary. tle glass ball, as in the Thoma-Zeiss apparatus. Malassez combined this suction capillary pipette with an artificial capillary in the following manner: Blood is drawn up by suction into the Potain mixer to the 1 mark, and a diluting fluid, called the “artificial serum,” consisting of —gum arabic specific gravity 1.020, one volume; sodium sulphate and sodium chloride, equal parts and each of specific gravity 1.020, two volumes—to the 100 mark, making dilution of 1 in 100. The pointed end of the mixer is then fastened to a rubber tubing connected with the artificial capillary, as seen in Fig. 545. The artificial capillary is set in a plate of glass which is too Of acubic millimetre; then 400 times that number multiplied by the amount of dilution represents the number of corpus- cles in a cubic millimetre. This method offered many difficulties: 1. Complicated artificial serum for dilution. 2. Introduction of blood without air into artificial tube difficult. 8. Difficult to clean apparatus. Hayem and Nachet devised an instrument (Héma- timétre) by which the blood and serum are obtained in Fig. 546.—Artificial Capillary as It Appears Under the Microscope. x 180 diameters. (From Ranvier.) two separate pipettes and then mixed in a glass receiver. A drop of this mixture is then placed upan a glass slide arranged as follows: A. circular well, similar to that employed in the Thoma and Zeiss apparatus, is con- structed with the accurate measurement of 1 em. in diameter and 0.2 mm. in depth. An eyepiece mi- crometer ruled in a large square and divided into sixteen little squares is then attached. One side of the large square measures exactly + mm.* (see Fig. 547). By counting the cells in the square and mul- tiplying this count by the fraction of a cubic millimetre which this Square repre- sents, and the number of volumes of the diluting fluid, the number of cells inacubic millimetre is ascertained. This oa ~ S409) ° q°c oO ®) Oo oo OP [exe O ° Fig. 547.—Appearance of Corpuscles with Hayem and Nachet’s Instrument. * One-fifth millimetre in depth by one-fifth millimetre on two sides pe square Ste the block of blood one-fifth (0.2) cubic millimetre— X5X5= 125. 41 Blood, Blood, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. is complicated, but, as will be seen later, it has contributed certain points toward the simple apparatus used to-day. In The Lancet for December 1, 1877, Gowers de- scribes an instrument which he calls the hemacytometer, and which more nearly approaches perfection than any already described; it therefore marks what may be con- sidered the border line between the ancient and modern Hane : ( i i Fic. 548.—Gowers’ Hzemacytometer. (From Kirkes’ ** Handbook of Physiology,” twelfth edition.) history of blood-counting by the actual enumeration method. Gowers’ instrument (see Fig. 548) consists of: A, Small pipette (with rubber mouthpiece for suction) which, when filled (with diluting fluid) to the mark on its stem, contains exactly 995 c.mm._ 5B, Another pipette marked to hold 5c.mm. (of blood). D, Glass jar for mix- ing (blood and diluting fluid). E, Stirrer (to stir blood and diluting fluid in glass jar). C, Brass plate with a cell + (0.2) mm. in depth and with the floor divided into 5 (0.1) mm. squares and a cover glass held in place by springs. A standard saline solution of sodium sulphate of specific gravity 1.025is employed; 995 c.mm. of solution is mixed with 5c.mm. of blood with the pipettes. These are mixed in the glass jar. A drop is placed in the cell in the brass plate and the cover slip held down by the springs. The cells are then counted in ten squares, and the calculation for 1 c.mm. of which this is a fraction made. As we review these descrip- tions of appara- tus we see that the effort of the inventors has been to over- come certain obstacles, 7.é.: (1) Reduction of the corpuscles to a countable number. Vie- rordt accom- plished this by dilution and by fixing the area to be counted to the cubic milli- metre. (2) Obtaining the blood so as to prevent clot, and to dilute accurately. Welker showed the value of accurate dilution. Potain’s mélangeur best accomplished this. 90000 lore) eo) fore) O08 Fig. 549.—Appearance of Corpuscles Under Mi- croscope with Gowers’ Instrument. 42 (3) Spreading the blood over an area thin enough to see each corpuscle. Malassez accomplished this with a long narrow tube; Hayem and Nachet with a cell whose depth was a fraction of a cubic millimetre. (4) Mapping out the area so that the eye could navi- gate upon it. Hayem and Nachet accomplished this with an eye-piece micrometer. Gowers, without an eye- piece micrometer, but with a marked-out slide. All these methods depend (as K6lliker has pointed out) upon the following priniciples: (1) A known quantity of blood for estimation (1 c.mm.); (2) a known dilution of a known quantity of blood; (8) a known fraction of a , cubic millimetre to be counted. Upon these principles and with the information obtained from the foregoing inventors, Thoma and Zeiss have con- structed their apparatus. This combines the mélangeur _ of Potain and the mapped-out cell of Gowers. Principle of the Thoma-Zeiss Mixer.—The mixer con- sists of a capillary portion and a dilated or bulb-like por- tion. The capillary portion enables one to procure a fixed quantity of blood that is free from clotting, if promptly taken; and the bulb portion enables one to pro- wbowl L00 N | R N Bowl, NN 4 nelle IN iN J fe | WN Fig. 550.—The Mixer of Thoma and Zeiss Corpuscle-Counting Appara- tus. Shows principle of dilution by comparison of pipette (a neces- sary instrument in dealing with a coagulable fiuid like blood) with an Cea receiver (in which a non-coagulable fluid could be di- luted). cure a fixed dilution. The principle of this mixer is best understood by reference to the diagram shown herewith (Fig. 550). Suppose the fluid to be diluted were wine or some non- coagulable fluid. Then we should pour the wine into the receiver, as shown in the diagram, up to the mark 1, and the diluting fluid up to the mark 100. This would be 1 to 100. Were we to pour the wine up to the .5 mark only (or +of 1), and the diluting fluid up to 100, ° we should have half as much wine as before to the same amount of diluting fluid, or in the proportion of 1 to 200. Half the fluid to be diluted with the same amount of diluting fluid has the same result as doubling the amount of the latter. Now blood cannot be poured in this way. An instru- ment must therefore be devised by which the blood can be taken free from clotting. Our receiver, therefore, is converted into a capillary tube and our pouring is re- placed by suction. That portion of the receiver marked off as 1 is converted into the pipette, and that portion of the receiver marked off as 100 is converted into the bowl. We now have an instrument by which a definite REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. quantity of blood can be drawn up together with a definite quantity of diluting fluid. This instrument, when full, represents 101 of blood and diluting fluid, or 1 of blood to 100 of diluting fluid. If the blood be drawn to the .5 or 4 mark and the diluting fluid to the 100 mark we have 1 to 200. The Thoma and Zeiss apparatus is usually provided with two mixers similar in all respects except that one is larger than the other: one for counting the white cells, the larger one; and one for counting the red cells, the smaller one. That for counting the red cells is all that is necessary, and, as will be seen later, is preferable to two separate proceedings. The diluting fluids, at first so complicated, have been much simplified. The object has been to obtain a medium as nearly as possible like that in which the corpuscles nor- mally float. Diluting Fiuids: (1) Normal, better named _ physio- logical, sait solution.* (2) Acetic acid 1 in 300 destroys the red cells and accentuates the nuclei of the white, and is therefore valuable in counting the white cells alone. (3) By using a basic stain together with the preserva- tive salts the results obtained separately by the other fluids are combined. The most satisfactory of these is the Toison solution. Formula. + ( Oo -CHIOTIGe2..s-.., 2.1162). 1.000 gm. | } DOUMIMMEStULD NATE. ace cnse tiers 8.000 gm. Pe CREE ae aie kent ors oie sie 30.000 c.c. [ UAV CEUWENRS nc is Sea one Pena Ss 160.000 e.e. + ESS 9 NG Fed (2 AR ge 0.025 gm. In the preparation of this solution it is advisable first to mix the sodium chloride and sodium sulphate thoroughly, and then to add these to the glycerin and water—the methyl] violet being added last. The brackets in the above formula show these steps in the preparation. Principle of the Counting Well.—Having thus an ap- paratus for taking a fixed quantity of blood with a fixed ae uy rey ei i 1 ¢.mm. FiG. 551.— A Cube Representative of the Amount of Blood from Which Corpusecle Enumeration is Made. The block represents 1 ¢.mm. quantity of diluting fluid, we must next have a means of counting the corpuscles. For this a glass slide is con- * Normal in chemistry indicates a solution containing the sum of the atomic weight of the salt employed in grams to 1,000 c.c. of dis- tilled water. As this is not the case with so-called normal salt solution, the term is misapplied. Physiological salt solution is, roughly, NaCl 3 j. to the O j. distilled water. + This solution must be kept in the dark and must be filtered from time to time as it losesits color and develops a fungus growth which seriously plugs the pipette. This solution preserves the red cells and by means of the methyl violet stains the white cells a iight purple, making the latter readily distinguishable and enabling 9ne to make the count of both red and white cells in one process. Blood, Blood, structed, with a well in the centre of the following known dimensions. It must be remembered that each of the various parts of this apparatus described has been con- structed to overcome an obstacle. The mixer overcame 0.1 1¢.mm. FIG. 552. the clotting and diluted the drop, thus reducing the num- ber of corpuscles to a countable figure. The well which we are about to describe, (1) reduces the cubic millimetre to a depth through which it is possible to see each corpuscle separately (a cubic millimetre of blood and fluid to the dilution of two hundred times would be so thick and con- tain so many corpuscles that the task would be beyond 0.100 mm. Fig. 553.—Full-Face View of Counting Stage. Dunning.) (German quadrat-square) = smallest square which measures z4, of a square millimetre (25 16 = 400).] (Drawn by Dr. E. (0.100 mm. = depth- 75 of a millimetre; 445 q.mm. human skill); (2) maps out that area so that the eye can find, as it were, the longitude and latitude of any point in the sea of corpuscles. What fraction of a cubic millimetre offers the depth and contains that number of corpuscles appreciable by the human eye? This fraction is found to be one-tenth of a cubic millimetre in 1 to 100 or 1 to 200 dilution of blood. The illustration (Fig. 551) represents a millimetre cube. Tf this consisted of blood, the depth would be too great for the human eye to penetrate and would contain so many corpuscles as to be beyond human skill to enumer- ate. We therefore retain two dimensions of the cube, but take only one-tenth of the depth. This layer of blood is therefore one-tenth of a cubic millimetre in a 1 to 100 or 1 to 200 dilution (see Fig. 552). The counting stage, to fulfil these requirements, must be constructed asfollows: The bottom of the well upon which the corpuscles rest must be laid off with a square whose dimensions are 1 mm. each way, and the well must be one-tenth ofa millimetre in depth. The illustra- tion (Fig. 553) shows the full face view of the counting stage. In the centre is seen the bottom of the well with a square laid off measuring 1 mm. each way. The second illustration (Fig. 554) shows the profile of this stage with the cover slip in place. The measure- ment from the under surface of the cover slip to the bot- tom of the well is exactly 0.1 mm. When, therefore, a drop of the diluted blood is placed 42 Blood, Blood, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. in this well and the cover slip isin place, those corpuscles which we see contained within the square, the dimen- sions of which are 1 mm. each way and 0.1 mm. in depth, are the contents of a cube of diluted blood measuring zo of a cubic millimetre. (Norr.—These microscopic dimensions, but for the present simple method of construction, would render this instrument in the making a very costly and delicate affair. In the manufacture of this counting well a glass slide similar in length and breadth, but a little thicker Fic. 554.—Profile View of Counting Stage. ing.) (Drawn by Dr. E. Dunn- than that employed for general microscopic work, is used. Upon a round block of glass the millimetre square is cut or pressed. This block of glass is cemented to the centre of the glass slide and forms the bottom of the counting well. Another piece of glass, like a thick cover glass but with @ rownd hole cut in the centre, is cemented upon the slide, so that the block of glass already in place oc- cupies, but does not exactly fit, the hole. The difference in measurement, from above down, between the upper surface of the round block of glass and the upper surface of the glass with the hole through it is just 0.1 mm. 1 mm. 1mm. Fig. 555.—Subdivisions of Counting Field of Thoma and Zeiss Ap- paratus. [1 sq.min.—y5 sq.mm.—q4y (25 X 16) sq.mm.] Thus the well with a millimetre square marked at the bottom and 0.1 mm. in depth is formed. The fact that the block of glass does not completely fill the hole in the outer piece of glass explains why there is left about it a groove into which the blood flows, if more than is re- quired exactly to cover the block of glass is blown into the well. This seems an objection, as currents are thus produced allowing many corpuscles to flow out of the mapped area. There seems no good reason for the pres- -ence of this groove except possibly that it obviates the additional expense of making the block of glass exactly fit the hole.) Principle of the Ruling of the Counting Well.—We now turn to the marking out of a millimetre square which is to render it navigable. Here, as before, an obstacle is to be overcome, viz., the inability of the human eye to keep its bearings when viewing several thousands of corpuscles. The first subdivision of this area (as first done by Nachet and Hayem on the eye-piece and by Gowers on the stage) +4 ~ is into 16 squares. But even this does not overcome the difficulty, and it is necessary still further to subdivide each one of these into 25 squares (Fig. 555). It now be- comes necessary to establish some boundary mark for Fie. 556.—Shows Method of Drawing Blood into Mixer. Diluting fluid near at hand. these 16 large squares, each consisting of 25 small squares. This is done by bounding each of the 16 squares on two sides with double lines. Now we can readily count the corpuscles in one of the large squares which is bounded on two sides by the double lines, and realize that this repre- sents 7; of the field; or in one of the small squares, and realize that this represents 3: of de, or (16X25 = 400), zt> of the whole millimetre square. On the glass slide (Fig. 553) will be no- ticed the figures 0.100 mm., refer- ring to the depth, which is 74 of a . 1 mm.; also go q-mm., referring to the smallest squares, each one of which measures £50 sq.mm., (x); of 5=o0) (Fig. ore os 5. Once these ma- thematical facts are Clearly under- stood, one may countin many dif- ferent ways. One small square may be counted, and the result multi- plied by 400; or 25 small squares, and the result 1G. 557.—Thoma and Zeiss Corpuscle-Count- multiplied by 16 ing Apparatus. Drawing diluting fluid into plea by 16, mixer. The blood has already been drawn The best method, in. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood, Blood, however, will be given in the following description of the use of the apparatus. Now that we understand the principle of the apparatus, let us proceed to its use: In order to obtain the blood the ear is punctured as for a fresh specimen, and the tip of the capillary tube inserted énto the drop and retained there while gentle suction is exerted, and the blood drawn either to the 1 mark, or the .) or 4 mark, as shown in Fig. 556. The latter is pref- erable, for the following reasons: (1) Less blood. (2) Difficult to stop sharp at the 1 mark without the blood passing on into the bowl and necessitating cleaning the instrument and beginning again. In using the .5 mark, if the blood pass the mark it may be soaked off the tip of the pipette with linen or blotting paper until the column stands opposite the .6 mark—cleaning, etc., not being necessary. : As promptly as possible, to avoid clotting, the pipette is submerged into the diluting fluid; and then, but not till then, suction is again made until the fluid stands opposite the 101 mark (Fig. 557). Suction must be gentle through- out, and especially so as the fluid is approaching the 101 mark, as it readily pops into the rubber tubing. The tip of the pipette must always be tmmersed in the fluid being sucked up, whether it be biood or diluting fluid, other- wise air enters the pipette and destroys the specimen. Directly the diluting fluid has reached the 100 mark the finger is placed on the tip of the pipette and the whole shaken in order that the corpuscles may, by the aid of the small glass ball in the bulb portion of the mixer, be thoroughly mixed with the diluting fluid (Fig. 558). As the pipette contains the diluting fluid and no corpus- cles, this must be emptied; and to be certain that this is done the bulb of the mixer is emptied one-third by blowing the fluid out. The diluting fluid should be allowed to act upon the blood in the mixer for five or ten minutes before the drop for counting is taken from the mixer. The counting stage is now employed. This stage and the cover sip must be free from dust particles. The latter (the cover slip), grasped with the clamp forceps, is placed conveniently at hand. A thick cover slip with accurately level surfaces, to prevent bending, is provided with the apparatus; but as this interferes with the use of the high-power lens, it is an objection. An ordinary cover slip may be used, if care is taken not to press down upon it with the objective. From the mixer a drop is blown on to the central raised table of the counting well FIG. 558.—Position of Hands in Shaking Mixer. (Fig. 559). The drop should not (1) flow into the well, (2) or contain air bubbles, (3) or particles of dirt. The cover slip is lowered until the fluid touches it, then the forceps are opened and withdrawn with a jerk as in lay- ing the cover slips for fresh specimen (see Fig. 5438). There should be no air bubbles, which may be avoided by observing the foregoing precautions. By holding the slide up to the light on a@ level with the eye and making pressure with the point of the forceps upon the cover slip, a series of varicolored concentric rings will be seen about the point of the forceps where it touches the glass. These are the Newton’s rings, which are seen only when two pieces of glass are in perfect ap- F1G. 559.—Blowing Drop from Mixer on to Stage. position, 7.e., when there are no dust particles, etc., be- tween them. The presence of these rings is therefore an evidence that the glasses are perfectly clean. Two to three minutes are now allowed for the corpuscles to sink through the depth of one-tenth of a millimetre and rest on the mapped-out bottom of the well. By at once observing the slide under the microscope this sinking process may be seen. Weare now ready to count; the lowest-power lens of the Leitz or Zeiss microscope may be used. This takes in its field of vision the whole counting area, but magnifies the corpuscles so slightly that the strain upon the eye is great (see Plate XIII., Fig. 2). The 7 or 9 objective of the Leitz takes in only 54; of the counting area, but does not strain the eye, and is therefore preferable, as with lit- tle practice the stage may be gradually moved until the whole area has been examined (see Plate XIII., Fig. 4), As the proportion of white corpuscles to red is about 1 to 700, there will be in a given area much fewer white corpuscles than red; and in the one-tenth of a cubic milli- metre there will be about 38 white cells to about 2,100 red cells. The task, therefore, of picking out three white cells in an entire field will be a simple one; while it is more practicable to count only a fraction of the field containing 2,100 red cells, and then compute the total by multiply- ing the number counted by the fraction adopted (see Plate XIII., Figs. 2-4). The following are the steps to be taken in counting the red and the white cells: Counting White Cells.—(1) Count cells contained in entire field, 7.e., 16 squares = ;4) of a cubie millimetre; (2) multiply by 10 to make the 1 c.mm.; (8) multiply by 100 or 200, according as the dilution has been made. Counting Red Cells.—(1) Count 4 squares, each consist- ing of 25 of the smaller squares: 4 squares out of 16 = yj or tof the whole 7; of a cubic millimetre; (2) this number multiplied by 4 gives the number contained in the #5 of a cubic millimetre; (8) multiply by 10 and by 100 or 200 as before. Now it must be remembered that every time we count a fresh drop from the mixer we decrease the range of error; so (remembering to shake the mixer well each time, as the corpuscles settle rapidly in the bulb) suppose in counting the white cells we take from the mixer 5 separate drops and count each upon the counting stage. Anaverage of the result, obtained by dividing by 5, gives us the num- ber of white cells contained in ;45 of a cubic millimetre. This average multiplied by 10 and 100 or 200, as before, will be a more accurate figure than that arrived at by counting one drop only. Suppose in estimating the red cells we take from the 45 Blood, Blood, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. mixer and count 2 separate drops, counting in the first drop the four corner squares (Squares Nos. 1, 4, 18, and 16 in Fig. 555), ¢.e., 34 of the whole field; then in the sec- ond drop the same four corner squares, 7.é., 74 also—our two counts combined will represent 8; or 4 of the field; this multiplied by 2 represents the whole field, 7@.e., 5 of a cubic millimetre. This multiplied by 10 and by 100 or o- ee ee It rh orn Pat pee asta hm pam | : op FIG. o6U.— Routes to be Taken in Counting Entire Field and One- Sixteenth of Entire Field. 200, according to dilution, gives the number of red cells in a cubic millimetre of undiluted blood. These calcula- tions may be expressed as follows: White Cells : ame Fs: x 10 x (100 or 200) =2; a, b, c, d, and e being the counts of separate drops taken from mixer; 5 the average number; 10 for the 7 of a cubic millimetre; 100 or 200, amount of dilution; z the number of corpuscles in cubic millimetres of undiluted blood. (Separate drop.) (Separate drop.) Red Cells: ( Cee ame foo SEED) Y ao wa (4 of field) = (14 of field) = 44 of field < 10 x (100 or 200) =z, a, b, c, d, each the number of corpuscles in ; of field—therefore together equal to 5%; or +of field; plus second count obtained from another drop from mixer equals 4 of field; and multiplied by 2 equals whole field. One-sixteenth of the field can be readily counted by counting znside the double lines up and down, as in ploughing a field, and then counting along two sides 77 the double lines. The route for counting in this way is shown by the dotted lines in the upper right-hand corner of Fig. 560. For counting the entire field the dotted line in the whole field of Fig. 560 marks the route. This method will be found to save much time. In order to avoid recounting corpuscles on the line, and to decide to which square these corpuscles belong, the following rule will be found valuable. Count only those corpuscles on the left line of the column down which you are counting, and in the 7, square count only those corpus- cles which lie on the double-line boundary of the square. With practice a blood count can be made in from 15 to 20 minutes, unless the blood be from a case of marked leucocytosis or grave angemia in which one wishes an ex- tremely accurate count. Cleaning the Apparatus.—The Thoma and Zeiss appara- tus has received much condemnation from the difficulty ex- perienced in cleaning it. By strictly observing the follow- ing rules, this difficulty will be almost wholly overcome. (1) If by accident the blood is drawn into the bowl before being mixed with the diluting fluid, immediately 46 draw up distilled water and proceed to clean as given below. Do not use alcohol until all trace of blood has been removed. (2) Do not draw the blood into the pipette until the bottle holding the diluting fluid 7s at hand and the cork out of the bottle (see Fig. 556). (3) See that the diluting fluid contains no flakes or fungus growth; if these be present, filter the fluid be- fore using. (4) Dry the mixer by drawing ether up and blowing it out. (5) See that the rubber tube is free from saliva and food particles. It is well to do this from time to time, while using the apparatus, by detaching the tube from the mixer and blowing it out and then passing distilled water through it. Suppose these precautions to have been taken and the diluted specimen to be in the bowl and our count completed; we then proceed to clean the mixer, (6) Remove the rubber tube, blow out the saliva, etc., which may have collected (see (5), above). Attach the tube to the pipette end of the mixer and blow out the con- tents of the bowl (Fig. 561). (7) Replace the rubber tube on the large end of the mixer and draw distilled water into the bowl. Shake the mixer well and blow this water out by reversing the tube as recommended in (6), each time blowing the rub- ber tube free of saliva. (8) With the tube on the big end of the mixer draw up 95 per cent. alcohol. With tube on pipette end blow this out. This removes the stain. If the glass is not entirely freed from stain, repeat until desired result is obtained. (9) With the tube on the big end of mixer draw in ether, and then (without reversing tube) blow the ether out through the pipette. This shows that the whole apparatus is clear and ready for use next time. If epithelium or mucus from the mouth, etc., gets into the bowl, it is best removed by drawing undiluted hydro- chloric acid up and then introducing an especial make of wire which the writer has suggested to Messrs. Eimer & Amend to procure. It is known in commerce as “stiff brass wire, B. & S. (Brown & Sharp), No. 31 gauge,” and has the advantage of being very fine but very stiff, and can be run the whole length of the Tho- ma and Zeiss mixer. With this wire, and most decidedly with all other wires, one must be careful to have no kinks, as these may break, leaving the wire in the mixer—an awk- ward accident. In the Deutsche medicinische Woch- enschrift, July 29, 18/007 ee eno ee R. Friedlinder, of Wiesbaden, de- scribed an_ instru- ment, devised by himself, for count- ing leucocytes. He was led to the con- struction of this in- strument by a sense of inaccuracy while using the Thoma and Zeiss counter. His objections to the latter instrument were, first, too considerable a dilution and therefore too few white cells from which to estimate; second, the calculations nec- essary With the Thoma and Zeiss instrument are so exten- sive that a small variation in the number upon which these calculations are based means an error of many thousands. Fig. 561.—Cleaning Mixer. Rubber tube on pipette end of mixer. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood. Blood, Friedliinder confirmed these objections by obtaining dif- ferent results in a number of counts of blood taken from the same individual on a single occasion. In order to overcome these objections Friedliinder had Zeiss construct the following apparatus: A pipette similar to that employed in the Thoma and Zeiss apparatus—dilution 1 in 10 or 1 in 20; a counting chamber 0.222 mm. deep x 0.3 mm. square, with the floor divided into squares—16 & 16 = 256 squares in all. The double ruling is omitted; a mechanical stage is em- ployed. In order, by this method, to arrive at a figure expressive of the number of leucocytes in a cubic millimetre, the fol- lowing formula is employed: Ne 2 MxQ A = amount of dilution. Z = number of leucocytes found in these sections. M = number of sections observed. Q = the cubic area between the floor of the counting stage and the cover slip—?.e., 0.09 « 0.22 = 0.0198. Example: Suppose 192 squares to have been counted and 1,522 leucocytes found; dilution 1 to 20. 20 X 1,522 192 x 0.0198 (Note: There is a mistake in Friedliinder’s formula; 1,0198 should read as above, 0.0198.) As diluting fluid he employs one-per-cent. salt solution tinged with gentian violet to whic is added one-third- per-cent. aceticacid. Thus the red cells are destroyed by = 8,007 leucocytes in 1 c.mm. Fia. 562.—Hedin’s Hematocrit. ( From yon Jacksh’s ‘* Clinical Diag- uosis.”’) the acetic acid and the nuclei of the white cells intensified, and at the same time the cell is stained by the gentian violet. The writer has had no experience with this instrument. If the steps as laid down in describing the Thoma and Zeiss instrument are followed the resuits should be as accurate. Asa clinical instrument Friedliinder’s would seem to be objectionable if for accuracy it is necessary to count a thousand or more cells. Unless we can arrive at accurate Fic. 563.—The Daland Hzematocrit. results by simple methods an apparatus loses its clinical value. A number of counting chambers have been devised. These differ chiefly in respect of the size of their rulings; the larger ones being given the preference in order to minimize the possibility of error. The following are some of these: counting chamber of Zappert, counting chamber of Gabritschewsky, counting chamber of Miessen, 2. CORPUSCLE ENUMERATION BY MEANS OF THE CEN- TRIFUGE.—We now approach the task of corpuscle enu- ne sos) (From Simon’s ** Clinical Diagnosis.’’) meration from a different point of view. As the cor- puscles are particles floating in a fluid, we should be able to precipitate these and measure the precipitate. If, as is the case in anzemia, the corpuscles are few, our sedi- ment should be less than in the normal. The task, then, is to throw these corpuscles down. This is done by the use of the centrifuge. This machine was employed at first to obtain serum, and its use for the latter purpose suggested its application as a corpuscle enumerator. Principle.—W hen blood is placed in the tube of a cen- trifuge and the apparatus rotated, the corpuscles collect as a red mass at the distal end of the tube and the serum as a colorless, semitransparent liquid at the proximal end. By taking a fixed quantity of blood and subjecting it to a fixed number of revolutions for a fixed time, and by noting and marking the height of the column of cor- puscles in the tube filled with blood from healthy indi- viduals, 2 normal standard is determined. Deviations. from this standard may be taken to indicate an increase or a decrease in the number of red cells. By counting the blood corpuscles with the Thoma and Zeiss instrument at the same time that the blood is sub- jected to the centrifuge, markings to express this count may be made upon the glass tube containing the column of corpuscles. The instrument for this method of counting is known 47 Blood. Blood. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. , as the hematocrit (aia, blood; xpity¢, a separator or dis- cerner), blood separator. Hedin’s instrument was among the first devised for this purpose (Fig. 562). In using this instrument the blood is sucked into a capillary tube together with a 2.5 per cent. bichromate of potash solution or Miiller’s* fluid, to prevent clotting, ber. of revolutions which they make, and each instrument should be tested to ascertain how many times it is neces- sary to turn the large handle in order to throw down the corpuscles so completely that no further revolving influ- ences them. It is therefore impossible to give any general rule for the number of revolutions necessary beyond say- ing that about four thousand revolutions of the cross bar to the minute should be the basis upon which to cal- culate. By noting the number of revolutions made by the cross bar to every single revolution of the handle this calculation can be readily made for each machine. The test, however, as stated above, is the complete precipita- tion of the corpuscles. The capillary tube is then re- moved and the column of corpuscles noted, the count being according to the figures 2, 3, 4, 5, 6, etc., in mil- lions opposite which the top of the column is found to be. (See Fig. 564.) Dr. J. Metcalfe Polk, working in the clinical laboratory at the Cornell University Medical School, has at my sug- gestion carried out systematic observations upon the hematocrit, comparing it with the Thoma and Zeiss ae ad Ae —— Fic. 564.—Daland’s Hzematocrit. (magnified) containing blood. and the tube placed in the limb of the centrifuge. The wheel is then revolved for a fixed time at a fixed number of revolutions (fifty to seventy seconds with the instru- ment here represented), when the red corpuscles will be found arranged as a sediment at the distal extremity of the tube, with a layer of white cells next, and above the white cells, again, the diluting fluid and serum. This instrument has been simplified very much by Judson Daland working in von Jaksch’s clinic (Fig. 564). By comparing the cuts (Figs. 562, 563) it will be observed how much simpler the latter is, the principle in both, however, being the same. An instrument (as shown in Fig. 565) is now upon the market for the attachment of tubes for testing blood, urine, or milk. In using the Daland instrument no pres- ervation fluid (bichromate of potash or Miiller’s fluid) is employed, a questionable omission. The instrument is operated as follows: A large punc- ture is made in the lobe of the ear in the usual way. 2,900 | 3,700,000 | 4,215,000 Pauls 4,060 | 4,100,000 | 4,472,000 Ist min.|} 4,350 Spot of corpuscles in 1st min.| 4,060 mt 2,900 | 38,900,000 serum at 75. is 4,060 | 8,700,000 Ill...{Ist min.| 4,490 XVII...|Ist min.| 4,060 : 35 sec 1,500 | 4,900,000 | 4,748,000 0 ee 4,090 | 2,800,000 | 2,570,000 | Per self. Ist min.|} 3,580 Two specks of cor- 1st min.| 4,060 ed, ** 2, 4,950,000 puscles in serum; Pe 3,770 | 2,600,000 | 2,650,000 | Per Dr. Brown. edge at reading ——— point ragged. XVIII...}lst min.| 4,070 , Be ee — Pape oa 8,900 | 1,800,000 | 2,200,000 | Per self. IV...|Ist min.} 4,300 : a rea aa 4,200 | 4,500,000 | 4,960,000 lst min.} 4,060 tee eS reat us 3,770 | 2,000,000 | 2,350,000 | Per Dr. Brown. Ist min.| 3,770 Corpuseles not all —— 20 3,625 | 4,700,000 thrown down. Two XIX.../Ist min.) 4,060 spots in serum. Pst 4,060 | 4,400,000 | 4,900,000 V...{Ist min.} 3,200 Ist min.| 4,060 ; rd ia 3,480 V6 es 4,060 | 4,100,000 3 aa 8,200 | 5,300,000 | 4,852,000 = os XX.../Ist min.|} 4,060 Ist min.| 3,770 25 4,060 | 5,000,000 | 4,864,000 | Per Dr. Scott. 24“ | 3.770 Ue oe 3,770 lst min.| 4,060 4th * 3,770 | 5,200,000 20 aes 4,060 | 5,200,000 | 4,656,000 | Per self. ; 5 7h Le oF Pen aan TE, EO a ous cart 5,500,000 From the above tests Dr. Polk draws the following conclusions: In revolving handle of hematocrit the num- VI...}Ist min.) 4,350 : ber of revolutions per minute was counted by the watch. 2d 3,770 | 4,100,000 | 4,068,000 _ | There was no stop between the first and second minutes 1st min.| 4,060 Spot of corpuscles | aS indicated under the time column. The number of 2a “ | 8,770 | 4,200,000 from 48 to 45. revolutions above a certain number, say 3,900, means very VII...lIst min.| 4,060 Spot of corpuscles 44 little, as it is impossible to maintain a uniform number per 2a ‘* | 4,060 | 3,650,000 | 3,976,000, to 45. five seconds throughout the minute and a half or two ao Mau at minutes, as the case may be. If at any time the handle Bee ety neni boo is turned with extra violence for ten or twenty seconds 2 te ; in one specimen and not so in the second, although the VIL.../Ist min.| 4,060 number of revolutions will be the same per two minutes, a ee ps nO | 2.08% 000 the reading of the first specimen will be from 4° to 8° Ist min.) 3,770 From 31 to-34, cor- | lower than that of the second. By looking over and com- 2d “* | 3,900 | 3,400,000 puscles thin, Sn paring columns 38 and 4, the above point will be evident. column read at 34. | ‘Time in taking a blood count with the hematocrit, from IX.../Ist min.| 4,060 puncture of the finger to the reading, was on an average 2d “ | 3,900 | 8,000,000 | 2,900,000 two minutes and forty-five seconds, or in round numbers, ; Rains” under three minutes; two minutes being allowed for turn- Ist min.} 3,900 ; : A = A 2a “ | 3,770 | 8,200,000 ing the instrument. Time of a Thoma-Zeiss enumer- See aaa) con esr licrs ania: ation was over twenty-five minutes. .../lst min.| 4, s . ° ‘ ‘ 4p 24 | 3°800 | 6,000,000 | 4,928,000 | - from 62 to 63. Time from taking the drop of blood to getting it into hematocrit and starting the same was never over fif- Ist min.| 4,100 teen seconds. The patient was close to the instrument. 2d 3,625 5,200,000 ____| The hematocrit made so much noise that it could not be XI... /1st min.| 4,060 Corpuscles thin from used in the wards. ; 2d“ | 4,060 | 4,450,000 | 4,504,000) 42 to 4414. Our conclusion as to the value of the hematocrit con- Ist min.| 4.350 Gorpiseles'thin'trom |; COL with that of von J aksch and Bleitreu, namely, that 2d ‘* | 4,090 | 4,200,000 41 to 42. the instrument is extremely useful for routine blood Semi nial 20u — | work, but that in accuracy it does not equal the Thoma- ...{18St mm A ida ¢ . "| 4046 | 4,600,000 | 5,088,000 Zeiss apparatus. bh eats ee ES ———$—$—$____ Our rule is to employ the hematocrit in routine ex- Ist min.| 3,800 Corpuscles thin from | amination, and, should a case present grave anzemia, to ad RU el eet ____ | verify the count with the Thoma-Zeiss apparatus. XII...|Ist min.) 3.625 Case of marked jaun- 3. ENUMERATION OF BLoop CORPUSCLES BY THE 2d “ | 3,480 | 3,600,000 | 4,624,000) di Bee s eer a OpricaAL Metuop.—The third method by which the enu- SS counts made yi rat] 7 ; r > ist min.| 4,060 different people, | meration of the corpuscles is made may be termed the *"! 41150 | 3,700,000 | 4,350,000| aboutsame results. | Optical method. : ° —_—__|—_._—_ a The instruments used for this purpose depend for their XIV.../Ist min.) 4,080 principle upon a change in color or opacity of the blood 2d. 8,960 | 4,900,000 | 4,968,000 according to its numerical value in corpuscles. a egy The globulimeter of Mantegazza* is the earliest of these ist min yes 4.600.000 instruments. The instrument consists of.a receiver of : ah CS}: glass with parallel walls. Into this receiver the blood is ; placed, after being diluted with ninety-six times its vol- XYV...{Ist min.| 4,060 %e ‘A E ij jeanne 2a ‘* | 8,950 | 4,200,000 | 4,920,000 ume of a solution of sodium carbonate. A lighted candle | eee is placed on the other side of the receiver, and the flame 1st min.} 4,060 : : 72. = Fe o %q 3.900 | 4,700,000 be gs prtne klin. Woch., April 8, 1878 ; New York Med. Record, Octo Vou. II.—4 49 Blood, Blood. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. observed through the diluted blood. Blue glasses, one after another, are placed between the observer and the blood until the flame can no longer be detected. Each i! uk “= in EE ILE TRB: { : ‘ ae — t FIG. 566.—Oliver’s Haemocytometer. subsequent examination. Ylue glass represents 125,000*red cells. From one. to thirty glasses may be added, when by referring to the table the number of corpuscles will be ascertained. Knowing, as we now do, that the amount of hemoglobin may be far below the number of red cells, this instrument seems to be based upon a false principle. The opacity and color of the blood are separate conditions, and bear no constant relation to the number of the corpuscles. Dr. George Oliver, of London, devised an instrument which he used in the preparation of his Croonian Lec- tures “On the Study of the Blood and Circulation,” pub- lished in The Lancet, June 20, 1896. This instrument de- pends for its principle upon the opacity of the blood, and has nothing to do with the color or tints, so that the term tintometer, which has been applied to it, is a wrong one, The hemocytometer of Oliver (Fig. 566) consists of the following parts: (1) A capillary tube, capacity 10 c.mm. (2) A glass receiver whose sides are flattened so that it measures less from before backward than from side to side. The tube isabout four inches in length, one inch in breadth, and about one-fourth of an inch from before backward. (3) Adropper. (4) A small candle, the size of a Christmas- treecandle. (5) Hayem’s solution (for formula, see p. 40). The principle of the instrument is that in an opaque fluid (like blood), contained in a flattened glass receiver with vertical striations, to which is gradually added a less opaque fluid (like Hayem’s solution), there develops, when such a receiver is placed between a candle flame and the eye, a point in the process of adding the less opaque fluid to the more opaque fluid at which the candle flame may be seen as a continuous bright line of light, which, before this point in dilution is reached, is not visible, and which after this point is passed no longer appears continuous, but as separate images of the candle flame. Moreover, the bright line of light consists of myriads of reflections of the candle flame produced by the vertical striations upon the glass receiver, which re- flections cannot be appreciated by the eye of the ob- server until the opacity of the blood has been overcome by the addition of the less opaque solution. The point at which this line appears is constant for normal blood, from which constancy a unit may be established to meas- ure blood rich or poor in corpuscles. The instrument is used as follows: The skin is punc- tured in the usual way and the capillary tube applied to the drop as in using the von Fleisch] hamoglobinometer 50 1, capillary tube; 2, graduated flattened receiver; 3, dropper; 4, candle and stand; 5, Bottle for Hayem’s solution; 6, bottles in which to place blood and solution for (see Fig. 578), the blood entering until the tube is entirely filled. There should, of course, be no air spaces in the column of blood. Excess of blood is wiped from off the sides of the tube, care being taken not to soak out the blood from the tube. This may be avoided either by not allowing the linen used to wipe away the ex- cess of blood to touch the ori- fice of the tube, or by hold- ing the finger over the upper end of the tube while wiping away the excess. The drop- per is now filled with Hay- em’s solution and the capil- lary emptied by allowing the solution to squirt through the tube, as shown in Fig. 567. This can be done by insert- ing the pointed end of the capillary tube into the mouth of the receiver and holding the dropper close to the blunt end of the capillary, then giving a quick pinch to the rubber end of the drop- per. This sends a strong stream through the capillary and empties it almost en- tirely. Repeating the process will certainly clean the cap- illary of blood. It is not necessary to attach the drop- per by a rubber connection, as shown in Oliver's illus- tration. This is difficult and takes time, and allows the blood to clot in the capillary. We may now either proceed at once to the estimation, or the mixture thus made may be put into a small bottle and estimated at any time within twelve hours. Thus several such mixtures may be made in the course of the morning’s round and placed in bottles properly labelled, the estimation being Fic. 567.—Oliver’s Heemocytometer. Washing blood with Hayem’s solution from capillary tube, by means of dropper, into flattened graduated receiver. made when the physician returns to his office. Or the specimens may be sent by mail, if the distance be not such as to require more than twelve hours in transpor- tation. These are distinct advantages over the Thoma- Zeiss instrument. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. If a candle flame ten feetaway be viewed in a perfectly dark room through the receiver held as shown in Fig. 568, the receiver containing blood and Hayem’s solution up to the 10 mark, for example, owing to the opacity of the mix- ture the flame will appear as a faint diffuse light. Ifnow we add little by little the Hayem’s solution, as the opacity becomes less the flame will become clearer, and will be caught by the vertical striations on the receiver, which act as minute mirrors to reflect the flame as a continuous line of light. When the mixture has reached that degree of opacity which allows of this phenomenon we read off the upper limit of the fluid in the receiver: 100 on the scale represents 5,000,000; 80, 4,000,000; y.e., 20 on the scale indicates 1,000,000 corpuscles. By moving the receiver slightly from side to side and from before backward, the line may be detected 1 at the sides a little before it extends across the receiver, a signal to the observer to add the solution cau- tiously drop by drop. Before the fluid has reached the height at which the line appears continuous the line is noticed to be blurred. As we add Fig. 568.—Oliver’s Heemovytometer. transverse bright line across flattened receiver. more fluid than is necessary to produce the continuous line, the line ceases to be a continuous one and becomes a series of minute but separate images of the candle flame. The point, therefore, at which the reading should be made is after the line ceases to be blurred and before separate images of the flame can be observed. The candle should be at least ten feet away and should be not larger than the ordinary Christmas-tree candle. The receiver should be held in the right hand and the thumb pressed well into the side of the nose so as to shut off all diffused light, as shown in Fig. 568. III. H#MoGLOBIN ESTIMATION. Apparatus and Technique.—The task of estimating the amount of hemoglobin has long been an unsatisfactory one, because all methods, excepting only the specific- gravity method, depend upon the comparison of colors, a subject upon which nearly all individuals differ, and upon the degree of opacity, which is supposed to vary with the amount of hemoglobin, a supposition by no means proven. The instruments group themselves into three classes, as follows: Based upon the | spit that Bizzozero’s chromocytometer) _} the Al amount of 2. Henoque’s heematoscope...... { °° | hemoglobin va- ries with the de- [ gree of opacity. 1. Gowers’ hemoglobinometer ) Based upon the 2. Von Fleischl’s “ supposition that 3. Von Fleischl’s the amount of and Meischer’s “ [ ‘*\ hemoglobin va- 4. Taylor’s z ses with the in- 5. Oliver’s tintometer “ | tensity of color. Watching for that degree of opacity at which candle flame will be seen as a ¢ Holding flattened receiver close to eye, between thumb and forefinger of left hand, while adding Hayem’s solution from dropper with right hand; 2, bottle holding Hay- em’s solution ; 3, candle ten feet away from observer and on a level with observer’s eye. Blood, Blood, Based upon the Gare ni that |} the amount of hemoglobin va- ries with the spe- cific gravity. i Hammerschlag’ s method } 2. Roy’s 1. Opactry Mernops.—TVhe Chromocytometer of Biz- zozero®* depends for its principle upon the supposition that the opacity of the blood varies with the amount of hemoglobin. The instrument may also be used to estimate the num- ber of red cells, but its value for this purpose is doubtful, for it is based in this application, as is Mantegazza’s in- strument, upon the false supposition that the opacity of the blood varies with the number of cells contained. When using it as a cytometer, instead of adding colored glasses as in Mantegazza’s instrument (see p. 49), Bizzo- zero introduces more and more blood until the opacity of the blood gives rise to partial obscuring of a candle flame. The thickness of the layer of blood producing this con- dition is then measured by comparison with standard observations, and the amount of hemoglobin estimated accordingly. The chromocytometer of Bizzozero is an instrument in- tended primarily for the estimation of he- moglobin. The name is misleading. The instrument is so called because the amount of hemo- globin is ascertained by two methods: (1) By observing the de- gree of opacity pro- duced by the hemo- globin unremorved from the corpuscle, and therefore the ac- tual corpuscular value of hemoglobin —in which applica- tion it is called a cytometer (Kitoc, a cell; wétpov, a measure). It does not number the corpuscles, as at first the name seems to imply. (2) By observing the color produced by the hemoglobin removed (dissolved) from the corpuscle and comparing this color with a standard colored glass— in which application it is called a chromometer (ypaxa, a color; “étpov, ameasure). Its application as a hemo- cytometer is a wrong one, as already stated. As a Cytometer (term understood as above described).— Principle: If a fixed quantity of blood be mixed with \ AK 177-77 ried Fig. 569.—Diagram Showing Construction of Bizzozero’s Chromocy- tometer. r, Well connecting with v, chamber formed by v’, which screws into v; 2 and 2’, glass windows. a fixed quantity of preserving fluid (saline solution), and the mixture placed in a receiver, and a candle flame viewed through the mixture in a dark room, then, accord- ing to the amount of hemoglobin and the amount of the mixture used, the flame of the candle will either be seen or will not be seen. By observing the amount of this * Atti della regia Accad. d. Se. di Torino, xiv., 1879. 51 Blood. Blood. mixture necessary, in normal cases, partially to obscure the candle, and calling this 100, we can, as more or less of such a mixture is required in diseased cases, ascertain the decrease or increase in the amount of hemoglobin. The instrument consists of a well which connects with a chamber closed at both ends with colorless glass. The chamber con- sists of two pieces of met- al, one screw- ing into the other. These are hollowed out so as to Lor men t.he chamber with- in (Fig. 569). By screwing or unscrewing one of these pieces the di- mensions of the chamber may be de- creased or in- creased. It Fig. 570.—Bizzozero’s Chromo- cytometer. Less diagrammat- ic than Fig. 569, showing side view. The outer screw unat- tached. Lettering same as in Fig. 569. m, Handle. (From ee von Jaksch’s ‘Clinical Diag- wili be seen nosis.’’) that if diluted blood “be placed in the well which connects with this chamber, the blood will flow into the chamber through this connection. But only just so much blood will flow into the chamber as is allowed by unscrewing the outer screw. When the outer portion of the instrument is screwed home (Fig. 571) no fluid at all enters the space between the screws—in other words, the chamber is then obliterated. Now by unscrewing or screwing the piece of metal which fits into the other piece and which, together with its fel- low, forms the chamber, we can increase or decrease the amount of fluid in the space between the screws. (1) Suppose now the two pieces of metal to be com- pletely screwed together, so that no space exists between them, the scale then stands at 0. (2) We fill the well (Figs. 569-571, 7) with 50 parts of normal saline solution to 1 part of blood; or, to be more accurate, by means of a pi- pette we mix 10 c.mm. of blood with 0.5 ¢.c. saline so- lution (0.75 gm. of NaCl in 100 ¢.c. water), which pre- serves the corpuscles. (3) A candle is placed in a dark room about four feet away from the observer. (4) The instrument is held by the left hand and close to the right eye, opposite the candle. (5) The two ends of the chamber, it will be re- Fic. 571.—Bizzozero’s Chro- mocytometer. Screws com- membered, have glass win- pletely screwed together, ob- -t ‘andle fis literating chamber. Well dows, so that the candle flame ary de clave a SE PN will be clearly seen. (6) With the right hand the pieces of the metal are slowly unscrew- ed, which allows the blood to flow from the well into the chamber. (7) As we introduce more and more fluid into the chamber, however, a de- gree of opacity must be reached at which the candle flame will be almost or wholly obscured. This is just what oc- curs. By observing the degree of unscrewing, so to speak, necessary to produce this opacity for normal blood, we obtain a unit with which diseased blood may be compared. By means of the table given below the amount of hemoglobin may then be ascertained. When the space between the glass windows is obliter- ated by screwing the outer portion home, the index on position one looks into the well. The round ring rep- resents the connection be- tween well and chamber. (From von Jaksch’s ** Clini- cal Diagnosis.”’) 52 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. the scale stands at 0. One complete rotation of the screw produces a space in the instrument measuring 0.5 mm. This is therefore the thickness of the contained solution of blood. One complete turn, however, renders the candle flame decidedly less visible. This complete rotation is therefore subdivided on the scale into 0.02 mm., 25 such subdivisions (0.02 * 25 = 0.5) constituting one complete revolution, and 50 such subdivisions (0.02 < 50 = 1.0) constituting 1.0 on the scale. From a number of observations (as stated by von Jaksch) upon the blood of healthy individuals, the outlines of the candle flame are distinctly seen through a layer of blood 44} mm. thick = 1.0, This, then, is the unit; z7crease of this number means decrease in amount of hemoglobin. For if we must in- crease the thickness of the stratum of blood in order to obscure the candle flame, it indicates that the fluid is poor in coloring matter, and that an excess is required to produce dimness of the candle flame. Scale Heemoglobin. Seale. Hemoglobin. 110 represents 100.0 170 represents 64.7 120 he 91.6 180 * 61.1 130 i 84.6 190 < 319 140 *~ 78.5 200 re 55.0 150 ve 73.3 210 sts 52.4 160 oc 68.7 220 " 50.0 If one has not this table at hand the reading can be readily interpreted by remembering that 110 = 100. Suppose, for example, the reading to be 160 on the scale; then: 100 :110 :: 160: ? 100 x 110 + 160 = 68.7 As a COhromometer (term understood as above de- scribed).—In addition to the parts of’ the instrument as already enumerated, there is a colored glass (see Fig. 572). This is introduced on one side of the instrument so that the colored glass and the glass windows of the instrument are side Gq D by side, as would be the C > case with a pair of opera glasses if one side were to consist of only the eyepiece, Ve 4 ) and that with a colored : 2 glass in it. In this use of the instrument, moreover, the hemoglobin is dissolved out with water in prepar- ing the blood for observa- tion. Principle: If a glass col- ored to correspond with a definite solution of hemoglobin be placed before a bright light (the sky) and beside a solution of hemoglobin to be tested, the color of the tinted glass and that of the solu- tion of hemoglobin will be found to differ. If, however, more or less of the solution be added, a point will be reached at which these colors correspond. By noting the amount of solution required to make these colors exactly correspond a scale may be made by which the amount of hemoglobin may be estimated. Given a tinted glass which corresponds in color with a known solution of hemoglobin. Given a known quan- tity of blood (10 c.mm.) with a known quantity of water (0.5 ¢.c.). If the blood to be tested contains much color- ing matter (hemoglobin), it will be necessary to add but little of the solution in order to make the colors cor- respond; if it contains little coloring matter, much will be required to make these colors correspond. These quantities are noted and compared with a scale, each quantity of fluid corresponding with a percentage of hemoglobin. By referring to Figs. 570 and 571, the working of the apparatus will be readily understood. The colored glass is not of the same intensity of color in every instrument, so that the glass must be tested for each instrument. Fi@. 572.—Bizzozero’s Chromocy- tometer. Frame holding tinted glass. Thisis placed by the side of the screw of the main appa- ratus. f, Tinted glass; 1, frame; ast, rod which passes through hole y in handle m of Fig. 570. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES Blood, Blood, The test is performed in the following way: Normal blood is tested, and is found to be, by the cytometer method, 110, and by the chromometer, say 180. One hun- dred and ten of the cytometer equals 100 hemo- globin. For this glass, then, 130 also equals 100. As in the case of the cytometer method, we construct a table from these relations. Suppose the reading with the chromometer to be 190. LOOM VSO R190 26? 100 x 1380 + 190 = 68.4. After a brief experience in using this instru- ment the author is inclined to commend it. Henocque’s Hematoscope.—This instrument also depends for its principle upon the supposition Tn addition to the apparatus already described, there is an enamelled plate, as seen in Fig. 575. This plate is placed behind the prismatic layer of that the amount of hemoglobin varies with the degree of opacity of the blood. In this instru- ment, in addition to the degree of opacity, the quantity of oxyhzmoglobin is ascertained by means of the spectroscope. This latter method places the instrument among the apparatus of an elaborately equipped laboratory and dimin- ishes its value for bedside work. Moreover, as von Jaksch states, there is a “difference of opin- ion as to when precisely the spectrum is formed,” making the conclusion drawn from the use of the in- strument “always somewhat arbitrary.” The instrument consists of two plates of glass, one placed above the other so as to enclose between them a prismatic space. The dimensions of this space are accu- rately stated and are the same for every instrument. * Thickuest > ef acehEs O31. Lerzoth BEATE: SOR IE oe y COV. Lev. Length, Seale -orem__ Lheichrest. oiel2 | C0 77n. G3 7i77. we wade ewe ----- -- ee Fic. 573.—Henocque’s Hzematoscope. Diagram showing dimensions of prismatic space formed by plates of glass. These plates of glass are in contact at one end, forming the apex of the prismatic space. The scale of measure- ment at this end is therefore 0. At the other end the glass plates are separated by a distance of 0.38 mm., forming the base of the prismatic space. By referring to the diagram (Fig. 573) and illus- trations (Figs. 574 and 575), this arrangement will be readily understood. The scale upon the glass is marked from 0 to 60, as observed in Fig. 574. There are two methods of using the instru- ment. (1) The first method is based upon the supposi- tion that varying opacity of the blood differs ac- cording to varying quantity of hemoglobin, so that by observing the former the latter may be estimated. To use the instrument upon this basis, punc- ture is made in the skin in the usual way and the drop brought to the orifice of the prismatic space, which, from its dimensions, will be ob- erved to be capillary. The blood on this ac- count passes readily into the space without being diluted, an advantage over the dilution methods. About six drops of blood are necessary to fill the space. Excess is wiped away. Fic. 574.—Henocque’s Hzematoscope Filled with Blood. Fig. 575,—Enamelled Plate Used with Henocque’s Hzematoscope. (From yon Jaksch’s ** Clinical Diagnosis.’’) blood, so that the figures 0, 10, 20, etc., correspond with the like figures on the glass plate of the hematoscope. At the apex end of the prism, and therefore at the thinnest portion of the layer of blood, the marking on this en- amelled plate will be visible ; but as the eye passes toward the thicker portion of the prism of blood a point will be reached at which the marking can no longer be seen. If the blood tested be rich in hemoglobin the opacity will be greater, and therefore the point in the series 15, 14, 13, 12, etc., at which this obscuring occurs will be higher, say 11 or 12, as seen in the illustration. If, on the other hand, the blood be poor in hemoglobin, the opacity will be correspondingly less, and we shall be able to see the figures 10, 9, 8, etc., in the series. “One hundred grams of normal blood contain 14 gm. of oxyhemoglobin. These figures, therefore, indicate the number of grams of oxyhemoglobin in 100 gm. of blood. For this use the author commends the instru- ment, (2) The second method is based upon the supposition that the richer the blood is in hemoglobin the thicker will be the layer necessary to detect through the spectro- scope the characteristic bands of oxyhemoglobin. By noting the thickness in normal blood at which the oxy- hemoglobin spectrum occurs, a scale may be made with which deviations from the normal may be measured. The apparatus, with the exception of the enamel plate, is used as before. The prism is fitted in front of a spectroscope and is turned until the oxyhzemoglobin bands appear, when this point is-noted on the scale. With normal blood the oxyhemoglobin spectrum is seen opposite 14 of the millimetre scale. Now for every millimetre on the scale the thickness of the prismatic space increases 0.005 mm. This can be demonstrated by multiplying 0.005 by 60, the 20 EGO 40 anata Ae attin Hemalescope d Menoegue Iie hk Nis es shle 3 WES Aa 746 (From yon Jaksch’s ‘* Clinical Diagnosis.’’) length of the scale; the result is 0.8 mm., the thickness of the prism at its base, ¢.e., at the 60 mm. end. As, therefore, for normal blood the spectrum appears at 14 on the millimetre scale, we determine the thickness of 538 Blood, Blood, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. blood required to produce this spectrum by multiplying 14mm. 0.005 mm. = 0.07 mm. This, then, is a unit; it is the thickness of normal blood required to produce the oxyhemoglobin spectrum. Suppose a specimen of blood produces the oxyhaemo- globin bands at 40 on the millimetre scale. The thick- ness of this specimen would be 40 mm. x 0.005 mm, = 0.2mm. Then: 7.€. ea a9 gm. of hemoglobin in 100 gm. of blood. An equation for any reading is the following: 7 f (y X 0.005) : 0.07 ::14 :@ in which y = reading on the scale. 0.005 = thickness of prism for each millimetre division on the scale. 0.07 = thickness of layer of normal blood by which oxyhemoglobin spectrum is produced—.e., at 14 on the scale (14 « 0.005 = 0.07). 14 = quantity of oxyhemoglobin in 100 gm. of normal blood. From these calculations one can make for himself a table which will at once give him the amount of the hemoglobin for any reading on the scale. Thus be- ginning with 5 on the millimetre scale, and substituting it for y in the equation, we get the following: (5 X 0.005) x 0.07 + 14 = 12.5. Therefore 5 mm. of the scale = 12.5 gm. hemoglobin in 100 gm. of blood. ; If we substitute in the same way 10, 15, 20, etc., the table becomes complete. The instrument has not been much used in this country, and, as already stated, except for the opacity method, it requires more apparatus than would be practicable at the bedside. The author has not had sufficient experience with this method to express an opinion upon its value. 2. Coton Mrtruops.—Before entering upon the de- scription of those hemoglobinometer instruments which depend for their principle upon the comparison of colors, it would be well to quote from Lovibond’s very interest- ing and valuable work on “ Measurements of Light and Color.” “Tt is almost impossible,” says Lovibond, “ without spe- cial arrangements to arrive at a reliable judgment between two colors which are very nearly, but not quite, alike, when these are placed openly side by side. The difficulty arises from the unequal incidence of light—sometimes of the direct light, frequently of the side lights, or from both combined. ‘The disturbing effect is so great that a slight change of position in either of the samples, or of the observer, generally reverses the first judgment. “The same causes account for the frequent differences of opinion between two persons judging the same color; in fact, the color sensations of our surroundings are. . . governed by the ever-varying conditions of light, sur- face, substance, texture, and chemical composition. . . .” The following are the experiments carried out by Prof. Lovibond: “Test Tubes containing colored liquids.—The first at- tempts were made with colored liquids in test tubes of equal diameters, and by these means some useful infor- mation was obtained. The liquids, however, svon changed color, requiring frequent renewals; and there was always a little uncertainty concerning their exact reproduction. Also a curious inequality of color relation was found to exist between the regular increase of strata thickness and their resulting color. This prevented liquids from being suitable as standards, because some liquids increase in color depth in direct proportion to increase of strata thick- ness. Some increase in color in a less but regular pro- portion to increase of strata thickness, whilst others increase in a less and irregular proportion. Another difficulty arose from the convex surfaces of the test tubes acting as a lens, and increasing the disturb- ance arising from unequal light incidence. The convex- ity was reduced by using larger tubes, and enclosing 54 them in a blackened case with narrow longitudinal aper- tures for looking through the middle of the tubes. The results, although useful, were too unsatisfactory for sys- tematic work. “ Colored glass was next tried, and long rectangular wedgesin glass of different colors, with gradually graded tapers, were ground and polished for standards, whilst correspondingly tapered vessels were made for the liquids to be measured. These were arranged to work, at the end of the instrument, up and down at right angles before two apertures, side by side, with a fixed centre line to read off the thickness of each before the aperture when a color match was made; but here also the difference of ratio between the thickness and color depth of the different colored glass and liquids proved fatal to the method. “ An incidental observation was made during these ex- periments concerning the difficulty of arriving at a final judgment with tapering colors, owing to one shade gradually blending into the next without a break of any kind to arrest the vision. The mental effort to arrive at a decision, under these conditions of gradual color-blend- ing, was troublesome and vexatiousin the extreme. Any person may realize this difficulty by attempting to fix a definite point by the vision in a graduated color line. I was enabled entirely to remove the difficulty by using separate glass slips for standards; the line of color de- cision made by each additional standard-glass slip used being a precise definition between the most minute shades. “The effect of these partial failures enabled me more clearly to define the conditions from which successful work might be expected, which are as follows: “Gauged Cells.—The cells for the liquids must have parallel transparent ends and be gauged to definite strata thickness. “ Optical Instrument.—The standard and sample must be viewed under equal conditions of illumination. “Suitable Light for Color Work.—Considerable differ- ences of view exist concerning the most suitable light for color work. Some authorities consider that daylight is too unreliable in composition, and that an artificial light, such as the electric arc, is best, as being always uniform. “Captain Abney’s work and apparatus at first sight go a long way toward establishing this view. Some valid reasons, however, in my opinion, exist in favor of daylight; as it isthe light to which normal vision is most accustomed, and it isavailable, without cost ata moment’s notice, during daylight hours, whereas artificial lights require to be worked in camera with somewhat expensive apparatus. Again, by far the largest proportion of artistic and commercial color work is carried on by day- light, so that measurements made by means of any other light must be transposed into terms of daylight vatues before reliable comparisons can bemade. Without doubt the vision can work longer and with less fatigue by day- light than by intense artificial light.” From the foregoing it will be seen that liquids and colored glasses have a distinctive color value, and that any method which employs blending colors, as the colored prism of the von Fleischl apparatus or the gradually diluted blood in the Gowers instrument, presents a wider field for error than that method which employs fixed and uniform colors for comparison. Also daylight is the most reliable. Gowers’ Hemoglobinometer.—This instrument is one of color comparison. Principle: Tf a colored fluid representing a very low percentage of hemoglobin be placed by the side of a so- lution of a fixed quantity of blood, to which water is added little by little, a point in the process of dilution will be reached at which the two colors correspond. By observing the amount of diluting fluid required to bring normal blood to a corresponding color with the fixed color, ascale may be made by which deviations from the normal may be detected. The parts of the instrument (Fig. 576) are (numbers correspond with those in cut): 1. A solution of picrocar- mine glycerin of the color of a one-per-cent. solution REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ‘ Blood, Blood. of normal blood, contained in a sealed tube. 2. An open tube graded from 10 to 120. 3. A pipette measur- ing 10and 20cm. 4. A dropper. To use the instrument: . Number | By Gowers’ instrument....... Tiatofotes 3: 3% per cubic By Thoma and Zeiss instrument........ millimetre. By Daland’s hemotocrit............++- By Oliver’s hemocytometer.......+.... Arucleated Normally, not present. Fad cells Normoblasts. : ‘ { Megaloblasts or gigantoblasts. Normally uniform. Polychromatophia = different intensity of stain in cells. 4 Staining .. AM@POIdeeete tse eens Pete ne : Hyaline. + Non-ameboid................; | Pigmented. etic: siete setters ate fs | Roger eaee cellular. oe echh aes Kull growno.-ce.c- Pig- Pigment motile... . Malarial } mented. ) ptm. [ UE terprer cet Ee cellular. < Flagellating...... os | Non-vacuolated.... | Pigment motile..... DPEOMENTING se pee ss ca te ete ches Sica ste Pigment: motile ......... Crescents .... 1 Flagellating........... ae : Pigment motile..... taste [ Round. bodies. i Flagellating .......5....- Hemoglobin : Normal, 85 to 95 per cent. By Gowers’ hemoglobinometer............ elestetets| st By von Fleischl’s hemoglobinometer.......... a ares By Oliver’stintometer... fouesiss ch cabic ae: Sarees ae By Roy’s specific-gravity method......... waereos a Colormindexe(mormial sel )iynetstantertlerceues tere Caterers tratciete White Blood Corpuscles : ( Normal 6,000 to 10,000. Number | By Gowers’ hemocytometer........... per cubic By Thoma-Zeiss heemocytometer....... millimetre. By Daland’s hematocrit............ sere By Friedliinder’s instrument........ ota Normal. Small mononuclear lymphocytes 20-30% Large mononuclear lymphocytes 3 aS Transitional lymphocytes....... 3 P 100 Polynuclear leucocytes....... .. 60-70 x Kosinophiles........... roe 2.4 MOOG Yass, WMastoeliay tases. eh sya ee 0.95 Myelocy tes. sg... << eevee DOt present, | Eosinophilic myelitis........ . Present (normal, 250,000 per cubic milli- Rlatesey act: metre). Absent. Plaques... ; Aer niet, Present. Fibrin..... i Afwents 67 Blood. Blood. Blood* { Present. Dust. ( Absent. Coagulation time (normal, two to three minutes). Gross test. Wright’s coagulometer tubes. Flame. Heat + Copper bar. | Sterilizer. Alcohol and ether 4a, equal parts. Formalin (10 per cent. in 95- [ per-cent. alcohol). Staining.. + Fixation Stain. Remarks. EBhrlich’s Eyepiece (Fig.598) supplies an important need. This instrument is so devised that accurate fields may be Fic. 598.—Ehrlich’s Eyepiece for Determining the Relative Values of White and Red Cells in a Dried 1, Screw for fastening eyepiece to microscope; 2, handle by means of which the square aperture (3) may be altered in size; 3, aperture reducible to definite relative sizes by obsery- Specimen of Blood. ing notches seen on upper margin of square. measured off on the dried specimen of blood and the rela- tive numerical values of white and red corpuscles thereby ascertained. The instrument is constructed like an eye- piece, and may be fastened to the microscope in place of the eyepiece. A handle projects from one side of the instrument, and when this is moved the square aperture noted on looking through the eye- piece is seen to increase and decrease equally on all sides according to the direction in which the handle is turned. On the uppermost side of the square (see Fig. 598) three notches will be noted. When the handle is placed so that the square is at its greatest size the dimensions of this square will be just sixteen times that of the square formed when the first notch is covered. The second notch indicates a square four times as large as when the first notch is covered; the third notch indicates a square nine times as large; and the largest square, as stated, is sixteen times as large as the smallest. Thus by counting all the red cells in the first or smallest square of a number of fields, and all the white cells in the fourth or largest square (which is sixteen times as large as the smallest) of a num- ber of fields, and multiplying the number of red cells by sixteen, we get the ratio of red to white cells in a dried specimen. ALKALINITY OF THE BLoop.—Engel’s (Berliner klin. Woch., 1897) modification of the Lowy-Zuntz method for estimating the degree of alkalinity of the blood places the apparatus among those ap- plicable for this purpose in bedside examinations. It consists of the following (Fig. 599): 1. A capillary pipette similar in construction to that used in the Thoma-Zeiss corpuscle-counting apparatus, but of somewhat larger size. The capillary portion is marked off into ten equal di- visions. The fifth mark indicates 0.025 c.em. and the tenth indicates 0.05 c.cm. tion is a mark that indicates 5 c.cm. 2, A receiver and a stirrer made of glass. 68 Above the bulb por- Fic. 599.—Engel’s Apparatus for Determining at the Bedside the Degree of Al- kalinity of the Blood. quantities of blood; 2, burette for acid solution; 3, litmus paper; 4, re- ceiver and stirrer for diluted blood while titrating. + REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. 3. A burette measuring 5 c.cm., and marked 1, 2, 3, 4, 5 in equal divisions. 4, Litmus paper. To Make the Test.—Blood from the ear (taken in the usual way) is drawn up to the 0.05 mark and distilled water to the 5.0 mark. These are mixed by carefully shaking the pipette, and then the mixer is blown out into the glass receiver. In the burette is placed a 7; normal tartaric acid solution. As stated elsewhere in this article, a normal solution in chemistry is the sum of the atomic weights of the chem- ical employed (in grams) in 1,000 c.c. of distilled water, The formula for tartaric acid is C,H.sO., and the sum of Cus Ones 8+ 6-+ 96 a eee Therefore 75 gm. of tartaric acid in 1,000 c.c. of water would represent a normal tartaric acid solu- tion. Aj;normal solution, however, is all that is re- quired, which would be: 1 gm. tartaric acid to 1 litre of distilled water. This solution is then al- lowed to drop from the burette into the receiver containing the diluted blood, which is stirred from time to time with the glass stirrer. Blue litmus is im- mersed from time to time, and directly this turns red, showing an acid reaction, the titration is at an end, and the amount of acid solution required to accom- plish this acid reaction (that is, the amount required to overcome the alkalies of the blood) is ascertained its atomic weights would be ra = 10, Seer eats Og soir OD, MSMHaGI AN ampere: atin 1, Capillary pipette for taking and mixing definite Blood, _ Blood. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. “***"OSvosIp SUTYSPOH °g *** -orrdoutsog "019 ‘ONOUTYOLLL ‘O ***** egjonuUATOd “Aoyetuuepul *_ **** O17 40070 ATI snoues 0[9 A Ul -OUdT] JO AIR] -[npow-ouslds (Zz) seers oneyqduls'T (1) “eIMeyne'y hi ex “SISOJADOONGT “yf SR uInjURjUL BIUt ~eyno[-opnoesd ‘vruiaeuy “9 pure **“STSOJBUIOITOOUIBH *G *** QSBOSTP S,UOSIPPV “F quosaid | yuasedd | yWeseid poonpel | peonpol aq Av | 9q ABI | 9q ABT oq Av | oq ABW 2 2 2 Pi [euLION |quasqy | TeuLION | [BULION | TeUIION | [eULION | JUOSqQY |‘JUasqyY |UeSqY |“WUeSqQY |[VULION | [BULION op *[BULION | *[BULION %68 lg sv Ysry se é [@ULION 2 2 [BULION | JUaSsqy |pasvesouy |poseoto9q| TRULION | [BULION | JUS Y | JUSqQY | JUOSqY | JUBSQY |[TPULION |posvotouy| ‘op [TVULION | TRULION wud 0} 000°0F 208 04 GS), posoq[@ | 04 000°@T é 2 é 2 [RULION | qUeSqy| [VULION |pesverouy] [VULION |poeseaideqd| JWesqy | JUesSqyY | JUeSqyY | JUESQY |AYUSIS |pesvetouy | “op [euIoN | [BULLION S]SIxo “UU BrULaeUue 04 000°0ST ssetun T 01 [| SB|pasvetoUurL pasealdep | pasRvaldep quasa.id | juaseid | Juasoid | yuvsord | MOTSe | A[JBveIs Apusys |AYUSTS 10 2 Z ps 2 posvarouy |\yuesaig | TRULION |poseveio9qd]| [BULION |paseotoeqd| JON | oq ABW | oq AVAL | 9q AB | 9q AL AIOA ‘op |1O[BUION| [BULION Ob eh. h BIUeVUe “ulUr") poust poseBaJ0UlL ssoyun 01 000°OL -ululIp | pasva.oep ATWSUS | 4 0} OJ, | JUeSeid | Juaseid | yUasetd yuUesaid | T 010g | ‘asBvetoOUT Anysys |AYOSI[s 10 é 2 2 2 [eULION | JUeSqY | [BULION |pasvetooq|10 [RUIION|pesvalouy | JON | oq AvP | 9q AVAL | oq AVP |*pataj[y) PoyeA ‘op |IO[BULION| [BVULION \ “mou 04 000°00T T 09 97 |pasreroul 2 2 é g JeuLION |qUeSAId | TRULION |pesvai0eqd| TRULION |posvosouy |JUeselg |JUeSeTd |JUeSaIq JUeSald |*patey{V| ATJBVALD ‘op psonpay | psonpeyy & bh Ob i hi -w#ue Jo mpeeas apRia qusts 0} Bur (WAR) aq AvuI quasald |[BULION | JUOSqY |[VUIION | TeULION | JUesSqy | [RULION | [vULION | [VUION | [BVULION | JUeSqyY | JUaSqyY | JUOSQY | JUBSQY |[PULON | [VULION |-Ploooy ‘[VULION ; asvoJ0Ul ly read S[[90 pod -nudjod seo. josaquina| psonpo.t o} 004 T 01 OOF|O7BIepoUur UL OSBaID |! TUL") 07 -1odoid Ut yeuou | Suro -ap 0} HOT}! 000‘000'F 408 01 GJ posvaroap moiy | 01 Q900'ET | UsIq |-todoid ut 0} é é 2 Aa Teulon | juesqy | [euON |pasvorouy| [eUION [410 [eULION]| JUESQy |yUaSoIg |JUESeT |JUISAId |palai1V | 0} O00'ZT | Alarea | Poonpery | 000‘000'S peonpel sjjeo = | ATpa yeu T 01 008 pod Ul W014) >" UU" 074 TeuLou -onpeld 943) 000°000'S #09 91 OG OF 94 OF uwlody vA0qe IN oy é Z é 2 jeuuoN | yUasqy]| TeuLION |peseeioed| TRULION |pesvorouT |yUesorg |JUeseId |yWOSeIg |yUOSeId |pale}/V | TRUION | GStH |‘peonper. | 000‘000'T ly ly yeuLtou poonpoel | *UIUI"d 07 2 [BULLION | JUaSq yy |1emMION | TeUMION | JUeSqY| TeULION | [eULION | [VULION | [eULION | 4UeSqyY |JUOSeIg |JUOSeIg |JUOSeTd |[PULION | TBULION MOT |%08 MOTI! 000'000'F %E01E | KGL 0109) 4819 | ZOE 0106 by 41 JoK $saq4000 | £Saq4000 | $8934900 | 5 Sa}4000 “umd | $saq4o -no| -nol -nol ney “uur : soynurm 0} |-OOneT (OOF OOT 41949 | QOT £49.49 | NOT Atodd | NOT At0A0 01 000‘0L “mUUL'D OF quasald | ¢ 01% | WeSC | 000'O0E [ATA UI [| JWASQY | ULE 07g JUL GL 01 09} UL g 01g |UT Og OF OZ] JUASqyY | JWASQY | yUeSqY | JUASQV |T 07 004 03.0009 i LS — = a . S z e = a S 5 aS ay 4 ulcer B = Sh Soe & 3 oga = S e = 8 +5 = = 7A o an So Ess B Pp 3 09 BS =} on° = S| BAB |: BR lee ee eee Baeeee ee eek megeles |) BS) eee) Baa) ch) 8 Bees & | oe) * : = g 43 25 | ge¢ | 888 | S*#2 E3"s| $2) 8 |eat| BF = ® 38 2 S fs g BE | EB | $22 | S72 |B & |PEBs 23 Shee ee e a Fi ; s re oe eee a *6 trio Pash cde Nea n B ‘ATAV |, SIL NI NMOHG GUY ASVASIC] HOV, AO SOLLSTUMLOVUVHY) AHL, (_&)) SOW], GUMUV]L AUV SHMALVAY AALLONLSIG] AH, “** erolaeue Alepuooeg “g soeeeeenouled ‘Tg eee nnnne STISOLOTYO ‘vy “sermaaue AIBUILId *Z 4OOT 01 06 000‘000'E seetesee* NOOT [VULION “| ‘doolq HHL HOAOUHL AGV] AX AVW HOTH AA AO SISONDVIC GHL ‘SSaSVaSIq AO ATAV], o> We} Blood. Blood-Letting. by noting the level at which the liquid stands in the burette. There is no one alkali in the blood which we can hold responsible for its alkaline reaction. It is therefore necessary to measure this alkalinity by taking a known alkali, say NaHO, as the unit. By ascertaining the amount of aj; normal tartaric acid solution required to neutralize a known quantity of blood, and then ascertain- ing the amount of sodium hydrate ‘neutralized by this amount of a; tartaric acid solution, we learn in terms of NaHO the amount of tartaric acid required to neu- tralize a known quantity of blood. Things which are ’ equal to the same are equal to one another. Thus by experiment we find that 0.5 c.cm. of 4 nor- mal tartaric acid solution neutralizes 0.05 c.cm. of blood; then 1,000 c.em. of 4; normal tartaric acid solution neu- tralizes 100 c.cm. of blood. Again, by experiment, we find that 75 gm. of tartaric acid neutralizes 40 gm. NaHO (28-+-1-+ 16 = 40). 1 gm. of tartaric acid neutralizes (as Ot 40) 588 mgm. of NaHO. Since 1,000 c.em. of 4 _ tartaric acid solution neutralizes 100 c.cm. of blood, 100'c.cm. of blood has an alkalinity of 5383 mgm. of NaHO. 0.5 c.em. of ~; normal tartaric acid solution neu- tralizes 0.05 c.cm. of blood. 1,000 c.cm. of -; normal tartaric acid solution neutralizes 100 c.cm. of plood. 75 gm. of tartaric acid solution neutralizes 40 gm. of NaHO. C,H.O. = se ee 5 neutralizes NaHO = 23 + 1+16 = 40. Then 1 gm. of tartaric acid solution neutralizes (75 40) 0.5383 NaHO. This is the quantity of tartaric acid in the 7A, normal solution (1 gm. in 1,000 c.c. of water). This, therefore, is the value in alkalinity—so to speak, in terms of NaHO —of the tartaric acid solution employed. Now on titration it is found that from 9 to 10 drops of such a solution are required to neutralize 0.05 c.cm. of blood. 10 drops equal 0.5 c.em., which equal 0.5 gm. 0.5 gm. equals 0.266 NaHO. - Therefore 10 drops equal an alkalinity of 0.266 NaHO. 1 drop = 0.0266 NaHO. It is perhaps better to bear in mind that 9 or 10 drops represent the normal, and to report examinations accord- ingly. For example, “6 drops required to neutralize,” “12 drops required to neutralize,” etc. It would also simplify the proceeding to use a solution of litmus in the blood solution instead of the papers. The Eyepiece Micrometer (Fig. 600) is of so simple con- struction and mechanism that its employment is to be recommended for more accurate clinical reports on the size of the blood corpuscles. The following explanation is taken from the Leitz ad- ‘vertisement of the instrument: Micrometric Measurements.—The scale of the eyepiece micrometer is divided into 7; mm. Each of these divi- sions represents, according to the objective used, a cer- tain absolute linear measure of the object, as shown in the following table: Absolute length of Absolute length of Number | bject represented Number object represented of by one division of ra) by one division of objective. the eyepiece- objective. the eyepiece- micrometer scale. micrometer scale. Millimetres. Millimetres. 1 0.054 ie 0.0026 2 028 8 0020 3 O15 9 0017 4 012 Immersion + 0022 5 0048 ia 3 ‘0018 6 os Dad .0014 When making micrometer measurements it is abso- lutely necessary accurately to maintain the tube length at 170mm. If this is neglected the measurements be- come unreliable or even worthless. 70 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. The above micrometer values are measured with eye- piece II.; in the other eyepieces they differ in an inap- preciable degree. Example: Let a scale of Hipparchia Janira, as seen with objective 6, cover 54 divisions of the scale longitu- dinally and 20 divisions transversely. Its actual length will then be 54 x 0.0084 = 0.184 mm., and its breadth 20 < 0.0034 = 0.068 mm. Suppose a valve of Pleuwr ostgma angulatum, meas- ured with objectives 4, 6, and 7, to cover 21, 74, and 98 divisions respectively; then the measurements of its length represent the following absolute dimensions: Objective 4: 21 X 0.012 = 0.252 mm. ¥ 6: 74 x 0.3004 = 0.252 “ vy 7: 98 x 0.0026 = 0.255 “ Tables of Magnifications.—The image seen in the micro- scope produces upon the eye the same effect as an object seen at the normal distance of distinct vision, 7.e., 10 inches. If, therefore, a rule be placed at the foot of the micro- Fic. 600.—The Eyepiece Micrometer. scope at a distance of 10 inches from the eye, it can be compared w ith the microscopical image of a scale di- vided into zjy mm. The quotient is the magnification of the obicuaye and the eyepiece combined. If, é.g., 92 mm. of the rule are found to cover 4% of the image of the micrometer scale, it follows that the magni ion is #2 = 130. The tables of magnification have been compiled in this manner and are sufficiently accurate for practical purposes. Thus, supposing the same specimen of Pleurosigma angulatum to be measured— (1) with objective 7 and eyepiece 0, (2) with objective 4 and eyepiece IL., and supposing the length of its image to be 67 mm. in the first and 22 mm. in the second case, then, since the actual size of the object is found by dividing the length of the image, as seen at a distance of 10 inches from the eye, by the magnification of the objective and eye- piece combined, the length of our specimen of Plewrosig- ma angulatum is: (1) 38%, = 0.248 mm. (2) 22 = 0.244 mm. In all these measurements a tube length of 170 mm. must be strictly adhered to. (Notrr.—As this article goes to press I learn that Jolles’s ferrometer has undergone such simplification as to place it among those instruments useful for clinical work. The eyepiece spectroscope is also a valuable addition to our clinical apparatus. Both of these instruments are as yet untested) but their simple construction and application commend ‘them to the clinician. ) BIBLIOGRAPHY. As space does not permit of a long list being intro- duced, the reader is referred to the very full bibliograph- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Kiood, Blood-Letting, ical note in von Jaksch’s “Clinical Diagnosis” and to the writings of the observers who are quoted throughout the article. Charles N. B. Camac. BLOOD-LETTING.—This title includes all methods of abstracting blood for therapeutic purposes, whether they are for a general or fora local effect. The terms venesection and phlebotomy are restricted to bleeding from the larger veins, for the purpose of influencing the system generally ; whilst leeching, wet-cupping, and ‘scarifieation are means of abstracting blood from the capillaries, the ‘effect of which is almost entirely local. General blood-letting, or venesection, is of very an- cient origin. References to it have been found in history prior to ‘the time of Hippocrates, and in the writings of this early authority it occupies an acknowledged posi- tion as a valuable therapeutic agent. During the many years that it has been employed it has been viewed with a varying degree of favor, and at times its advocates have employed it in all forms of disease and in a most extravagant manner. The seventeenth century and the early part of the present century mark the periods of its greatest use, during which excessive and repeated bleedings were constantly employed. The amounts of blood removed seem astounding at the present day. For a pleurisy 5,520 gm. were abstracted during a period of several days; in a case of pericarditis it was found necessary to abstract, on different occasions, 721, 720, 960, 1,200, and then 1,440 gm. before the patient wae relieved ; and, in a case of inflammatory rheumatism, twenty pounds of blood were taken during the progress of the attack. In the early part of the century, medical opin- ion went to the other extreme; the practice fell into dis- repute and was almost entirely abandoned. During the last twenty-five years its use has been revived. Many of the older practitioners who had never forsaken its use have been more outspoken in advocating its therapeutic powers. At medical gatherings, many papers have been read and numerous discussions have followed, in which venesection has been very generally supported. Its em- ployment has now assumed a more rational character. The advance in our knowledge of physiology and a closer clinical observation have made clearer what its effects are upon the system, and we now employ it with a definite object in view and restrict its use to a much more narrow sphere. Venesection exercises what may be termed a mechan- ical effect upon the circulation, as well as a general effect upon the system. When a certain proportion of the blood is removed the tension of the blood-vessels is at once lessened, the degree depending upon the amount withdrawn. The effect is but temporary, as that which is lost is rapidly renewed; but, if any disturbance of the circulation exists, it is sufficient to allow the equilibrium to be regained, the heart beating more easily and the blood flowing more freely through the vessels. The general effect upon the system is of the utmost importance. Accompanying the lowering of blood pressure and loss of blood cells, there is a diminished activity of the various functions. The heart’s action is quieter, respiration goes on more slowly, tissue changes are less active, and there is a lowering of body heat. This depression is but temporary. Ina few hours there begins a renewal of the blood, tissue changes are ac- celerated, the nervous system is improved by a stimula- tion of the nerve centres, and general bodily improve- ment is the result. At the International Medical Con- gress for 1900, in the discussion upon this subject, M. A. Robin stated, as the result of many years’ observation, he was satisfied that after moderate bleeding of 150 to 250 gm., polyuria is regularly observed, and the excretion of solids is increased. A greater amount of air is taken into the lungs, as much as sixty-one per cent., and the proportion of oxygen consumed by the tissues is corre- spondingly increased. When the bleedings are renewed the reaction is slower, and when they are frequently repeated, a state of anzmia ensues, with a tendency to degenerative changes. Inpicatrons.—The indications for bleeding may be summed up under three heads: (@) when there is exces- sive vascular tension; (2) when it is desired to obtain the benefit of its physiological action upon the various tissues and organs; (¢) when. it is believed that good may result from removing a definite amount of blood, and with it a certain proportion of toxic material, from the system. There is no difference of opinion as to the value of venesection in all conditions in which there is venous engorgement. It may be thought desirable to try the nitrites and allied drugs for the purpose of “bleeding into the arteries,” or to employ hydragogue cathartics or diuretics to unload the congested vessels; but if these measures fail, all are in favor of bleeding. The cause of the obstructed circulation may lie in the heart or in the pulmonary tissue. The effect of either of these causes is an overfilled and possibly a dilated right heart, distended veins, and more or less congestion of the various organs. In this condition the removal of blood from the venous system affords prompt relief. The laboring heart beats more freely, the arteries become filled, and the congested veins and organs return to the normal. The dyspneea disappears, the dusky hue of the skin fades, and the general condition of the patient is at once improved. Mitral disease, when compensation is failing, and a feeble heart that is suddenly overtaxed, are the two conditions that most frequently give rise to these distressing symptoms. In such cases, when the dilatation is extreme and the force of the heart very low, venesection must be prompt to be of service. Among these cases may be included many instances of cardiac failure that occur during the administration of a general anesthetic, when the dilated heart becomes suddenly overfilled and unable to empty its cavities. A sudden blow over the heart may suffice to cause a powerful con- traction, or the withdrawal of blood will relieve the pressure and allow regular contractions to be re-estab- lished. Of the pulmonary causes of venous congestion, emphysema is the most common, and in this condition marked benefit will follow the withdrawal of blood. Cases of bronchitis and those in which there isa tendency to pulmonary cedema afford favorable conditions for this treatment. Venesection is also of service when the arteries show a condition of increased tension, when the pulse is full and bounding, and when a condition of general plethora pre- vails. In these cases the relief afforded by the with- drawal of blood is also very marked, the reduced blood pressure relieving the congested organs and often pre- venting cerebral hemorrhage. In the convulsions of uremia, and especially in puerperal eclampsia, when there is the same arterial tension, the value of venesec- tion is unquestionable. The relief is immediate, and the severity of subsequent attacks is likely to be lessened. In puerperal states there should be no hesitation in re- sorting to it, if the arterial tension is abnormally high; and the fact that a free loss of blood has occurred dur- ing labor does not warrant the belief that venesection will be any less effective in relieving the tension. In these cases much of the benefit is due to the reduction of blood pressure, and much also may be explained by the favorable influence exerted on the tissue changes and by the increased oxidization. In addition, it is also suggested that the increased nutritive changes neutral- ize the poisons circulating in the blood and convert them into harmless products. It is difficult to determine to what extent the benefit should be ascribed to the actual removal of toxic mate- rial from the body (with the blood that is drawn off), yet we find that there are many eminent authorities who lay great stress upon this explanation. To increase the usefulness of the procedure in these toxic cases, it is recommended that the bleedings should be very free and that the blood lost should be replaced by normal saline solution, either administered subcutaneously or injected directly into the veins. The effect of venesection in lowering temperature and allaying the symptoms of inflammation would suggest 71 Blood-Letting. Blood Stains, the wisdom of employing it in the treatment of fevers and inflammatory diseases—a practice which was so much in vogue at the time when venesection was used empirically. This proposition, however, does not meet with favor. It is maintained that the relief afforded is but temporary, and that the tendency to fatty changes, present in pyrexia, is heightened by the repeated with- drawals of blood. The symptoms undoubtedly show marked improvement immediately after the operation, but the greater debility which results and the prolonged convalescence prevent its general acceptance. The only acute disease in which venesection receives much atten- tion is pneumonia. In addition to the benefits derived from the lessening of the plethora and the easing of the overworked heart, the lessening of the inflammatory process and the probable limiting of the extent of the consolidation must also be considered as results of some value. At all events numerous cases have been reported in which venesection has proved serviceable, and the subject is therefore worthy of every considera- tion. It is evident, however, that if any benefit is to be derived from this method of treatment it must be begun early before the pathological processes have made much advance. When it is resorted to at the outset, in a plethoric patient with stlenic symptoms, a full pulse, difficult respiration, pain, and fever, the operation acts most favorably, and there is every reason to believe that it renders the attack less severe. Frequently the vene- section is resorted to too late in the disease as a last re- sort, and although the distressing symptoms may be allayed for the moment, the ultimate result is rarely fa- vorable. METHOD OF PROCEDURE. —Formerly, blood was withdrawn from the veins of the arm, the external jugular, the veins beneath the tongue, the scrotal veins, and the veins of the leg; but at the present time a vein on the anterior sur- face of the forearm is the one chosen, unless some particular reason exists why another should be: selected. The veins in this region that become most promi- nent, when the circulation in them is arrested, are the median cephalic and the median basilic. The former is the proper one to select, as the median basilic is in close relation to the artery. The median cephalic is external to the tendon of ; the biceps and away from oe g any region of danger. It 2 will be found, however, that the size and promi- nence of the veins in front of the elbow vary great- ly, and generally the most marked one is selected re- gardless of its name or po- sition: SS (at sina res Fic. 601.—The Superficial Veins of the Forearm ; Skin Removed. a, Median cephalic; b, cephalic; c, brachial; e, basilic; f, median basilic; g, anterior ulna; d, me- dian nerve. tion strict antiseptic pre- cautions should be observed in the preparation of the site and in the selection of the knife and dressings. The arm is allowed to hang suspended and a firm bandage is applied above the elbow, sufficient force being employed to compress the superficial veins, and yet not enough to in- tercept the arterial flow. The vein is opened either longi- tudinally or in a direction slightly oblique to the axis of the 72 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. In performing the opera- vessel, the point of the blade being inserted directly into the vessel and withdrawn with a downward cutting mo- tion. Before one makes the incision he should place the thumb of the left hand below the point of opening, in order to secure the vessel firmly. Care must also be observed that the skin is tense and in its proper relation to the vessel, otherwise the incision through the skin may not coincide with the opening into the vein, and instead of a free flow of blood there will be only an exudation of blood into the cellular tissue. As soon as the blood flows freely, the pulse of the other arm and the patient’s face should be kept under observation to de- termine the effect on the cir- culation and to detect any symptoms of syncope. Twenty, thirty, or even forty ounces should be removed, according to the condition and temperament of the pa- tient. The quantity taken should always be sufficient to make a decided impression upon the circulation. Fre- quently the amount with- drawn does not exceed a few ounces. This is too small a quantity to afford any bene- fit to the patient, and as a further result venesection is discredited. When sufficient blood has been removed the flow is readily checked by applying a compress over the incision, removing the con- stricting band, and bandag- ing the arm, which bandage may be removed in twenty- four hours. It is often desirable to abstract blood from some promi- nent part for the purpose of relieving a local hy perzemia or congestion, as in many bruises and ecchymoses, in dis- ease about the eye, nose, ear, gums, etc., and in some forms of cellulitis. Such local blood-letting is also oc- casionally employed to lessen the congestion of deep organs by withdrawing blood from the surface of the body near to the affected part. In all cases the biood flows from the capillaries or superficial vessels, and the quantity is very slight in comparison with that which is abstracted in general blood-letting. 'To accomplish this end, leeches, scarification, and wet-cupping are the means employed. LeEecuinc.—This means of locally ab- stracting blood is still frequently employ- ed, but not to such an extent as formerly. When any large amount of blood is re- quired, a number of leeches must be used. A single leech will absorb from two to three drachms of blood, and this may be increased as much more by warm fomen- tations applied after the leech has dropped off. The leeches may be placed in a wine glass which should then be inverted over the desired spot. If the area is very lim- ited, or if-the blood is to be withdrawn from the nasal cavity, gums, or any cav- ity, a leech: glass should always be util- ized. The leech will bite more freely if removed from the water an hour or more before needed, and for the same reason the part should be thoroughly cleansed. | When a leech shows no inclination to bite, ae rubbing the skin with sweetened water 808 Gjace Will sometimes induce it to fasten upon pee se the spot. The peculiar bite of the leech Fig. 602.—Forearm with Liga- ture Applied. Finger at june- tion of median basilic and median cephalic veins. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. always leaves a permanent scar, and care must be ob- served in selecting a site which is not conspicuous. SCARIFICATION AND CuPPING.—By these means blood is abstracted through small superficial incisions into the skin, the flow being augmented by the cupping glass when that instrument is employed. The incisions may be made with an or- dinary knife or lancet, or by means of a scarificator. In the latter instrument the blades may be adjusted to any de- sired length so that the cutis vera of the part may be incised without pene- trating to the deeper tissues. The cup- ping glass may be one of those specially constructed for this purpose, or an or- dinary wine glass may be made to serve the same end. The cavity of the glass is heated over a spirit lamp, or by burning a small quantity of spirit in it, and then the glass is quickly invert- ed over the desired part and placed in such a way that the air will not enter. As the heated air cools its density is increased and suction force is ex- ercised upon the incised surface. The glass should be removed as soon as it ceases to act and a fresh one ap- plied. A cupping glass with a rubber bulb attached, on the principle of the ordinary breast pump, is also util- ized. Dry Cupprne.—Very. frequently cupping glasses are applied without an incision being made for the removal of blood. This is known ‘as “dry cupping.” The appli- cation of the glasses produces a rapid flow of blood to the part, and when repeated rapidly over a small area, the withdrawal of blood from organs lying below the surface is sufficient to relieve them if inflamed and con- gested. A single glass may be applied and quickly re- applied, but it is more satisfactory to employ a number of glasses and apply them at the same time. They are applied after the same manner as described for wet cup- ping. Dry cupping has the advantage of not making any incision and not causing any scar. The therapeutic action is somewhat different from that of wet cupping, as the counter-irrita- tion is much greater and more pro- longed. Junod’s boot isan instrument prepared on the same principle as that of the cupping-glass, its purpose being to withdraw blood from the body into one of the limbs, in order that relief may be afforded to congested organs without the permanent loss of any blood. It consists of a metallic vessel into which a limb may be placed and which closes so tightly that air cannot enter or escape, except by means of an exhausting syringe. As the air is with- drawn from the cavity, the blood flows into the vessels of the limb which be- comes greatly swollen and congested. This appliance has never met with much favor, as the constitutional effect is not very satisfactory and the local! action is often severe. Beaumont Small. BLOODROOT.—Saneuinaria. Red Puccoon. “The rhizome of Sanguinaria Canadensis L. (fam. Papaverace), collected in the autumn” (U.S. P.). Itis doubtful if this definition can be complied with, as the aerial portions die in early summer, and before fall all traces which would indicate the presence of the rhizome have disappeared. The plant is a low perennial, with a thick, fleshy, hori- zontal root-stock, from which one or two leaves anda single handsome white flower appear early in the spring, enclosed at the base by several sheathing scales. The leaves are kidney-shaped, variously lobed, and grow much larger and broader as the season goes on. The flower is about 3 cm. across (one and one-fourth inches), regular, perfect, spreading; sepals two, falling early: petals from six to twelve, rather narrow; stamens nu- Fic. 604.—The Scar- ificator. Fic. 605.—Cupping Glass, with Elas- tic Rubber Cap or Bulb. Blood-Letting. Blood Stains, merous, ovary and capsule one-celled, with two placente ; ovules (and seeds) numerous, with prominent caruncles. An opaque, orange-colored juice is found in all parts of the plant, especially in the rhizome, where it is very abundant and dark. Bloodroot is a native of North America, and is occasionally cultivated as an ornamental plant both here and in Europe. The dried rhizome is about 5 cm. (two inches) long, and 1 cm. in diameter, slightly flattened, indistinctly annulated, and evidently shrunken and wrinkled. It is reddish brown externally, variously bent and twisted, and now and then branched. It breaks with a short fracture, and displays a pink sur- face, finely dotted with dull red points; this surface becomes dark by exposure, and final- ly is uniformly brown- ish red. Odor slight, disagreeable. Taste bitter, acrid, nauseous, and persistent. Pow- der sternutatory. The principal con- stituent is the alkaloid sanguinarine (CaoHis NO,), discovered and named by Dana in 1829. When pure it is in white crystalline needles or tufts, insol- uble in water, but eas- ily dissolved by alco- hol, ether, oils, ete. ; it forms with the princi- pal acids beautiful , salts of brilliant orange or red color. The pow- der excites violent sneezing. Its _ taste, when dissolved, is that j=) of the rhizome inten- yee sified. _Chelerythrine ‘ (CoiHi7zNO,) exists in smaller amounts and yields yellow salts. Small amounts of at least two other alkaloids exist, with irritant resin, starch, citric and malic acids. Action.—The several alkaloids of bloodroot have very dissimilar actions when used separately, but that of sanguinarine is overpowering and determines that of the drug. It is amost powerful irritant, locally and system- ically. It was formerly used as a caustic for morbid growths, and has had many uses as a counter-irritant. It is powerfully irritant to the mucous membranes, and sialagogue. It is a powerful and even fatal emetic and cathartic. Systemically, it irritates both the spinal and cerebral centres, producing tetanic convulsions and in- toxication or violent delirium. It depresses muscular fibre, and this at length greatly depresses both the circu- lation and the respiration. These properties can be utilized, by small doses, in im- proving both appetite and digestion, and in producing expectorant effects, the latter either by internal adminis- tration, or by inhalation of very.weak preparations, or by application to the throat. It was formerly a much-used emetic in doses of gr. xv. to Ix., but this use is now considered barbarous. It is very little used at the pres- ent time, and then chiefly as an expectorant, in doses of 0.2 to 0.5 gm. (gr. iij. to viij). Its excretion is accom- panied by stimulation of intestinal and renal secretion and of peristalsis. It is also a stimulating emmenagogue. A fluid extract and a fifteen per cent. tincture, each con- taining a little acetic acid, are official HAH. H. Rusby. BLOOD STAINS.—In criminal trials the medical wit- ness is often called to determine whether stains found on weapons—as knives, clubs, or daggers—or upon the Fic. 606.—Bloodroot. 73 Blood Stains, Blood Stains, clothing of a suspected person, or upon the floor, walls, or ground where a homicide is supposed to have been committed, were caused by blood or by some other coloring matter. So also it is often equally important to determine whether stains acknowledged to be blood are the blood of a human being or that of one of the lower animals. The object of this article is to show how, and to what extent, these important questions may be an- swered. Such investigations have often served to con- vict the guilty, and in other cases triumphantly to acquit the innocent. The examination of blood stains éalls for the considera- tion of: (1) physical characteristics; (2) chemical reac- tions; (8) crystalline properties; (4) optical properties; and (5) microscopical appearances of blood corpuscles and other constituents of blood. 1. PuystcAL APPEARANCE OF BLoopD Srains.—The color of blood stains varies with the amount of serum and the absorbent properties of the object upon which the stain dries. Generally the more permeable the tissue or object stained, the brighter is the color after blood has dried upon it. Upon polished steel or other metal, blood dries in dark brown, shiny scales, however thin the blood may be. Upon silk or glass it assumes about the same color as upon polished metal. Upon varnished or very hard wood, blood stains have also a dark shining surface. Put upon soft porous wood, or any soft. tissue, as cotton cloth, the blood displays a dull brown color or a rose tint, yet even on cloth a thick clot, when dry, presents a brown but glistening surface. It sometimes happens that upon tissues or objects of a brown, maroon, or dark blue color, blood stains are quite invisible by full daylight, but they become con- spicuous by artificial light, especially if examined by light obliquely reflected. This is especially the case with dark-colored furniture, wallpaper, or any dark paint, on which blood stains easily seen by the light of a candle are quite invisible by daylight. Stains upon steel or other metallic instruments, if quickly dried by exposure to the air, are cracked and of a fine red color; but stains on similar instruments, kept in a damp situation, are of a dirty brown, tending toward a yellow rusty color, surrounded with an ochrey areola, yielding no color or albumen in water; even a solution of potash extracts only a small quantity of albumen. Upon glass, marble, plaster, flint, sandstone, and earth, blood stains preserve their ordinary characteristics; but upon wood containing tannin they form with the tannin an insoluble compound, and water in which such stains are macerated fails to yield characteristics of blood. In such cases the surface can sometimes be scraped off and tested free from the tannin. On felt and some kinds of cloth, blood forms shiny spots appearing like mucilage. In examining garments, searching for blood stains, a small magnifying glass is of great service in distinguishing small specks or drops of blood. 2. CHEMICAL REACTIONS.—(a@) Guaiacum Test for Blood. —If any red substance is suspected to be blood, place a drop on white paper; or if dry, moisten with water and then place it on the paper. Let fall upon the stain thus formed a drop of tincture of guaiacum. If the stain turns blue with no other treatment it is not blood; or if it contains blood it also contains starch, a salt of iron, or some other foreign substance. If it does not turn blue by the action of the guaiacum, drop upon it a watery solution of hydrogen dioxide, when, if it is blood, it will quickly assume a beautiful sapphire blue color. A par- ticle of blood scarcely visible to the naked eye may be detected by this test. If the blue color does not quickly appear by this test it is not blood. If the stain gives the blue color by this test it may be blood; and other tests may be applied to determine with certainty that it is. The white paper should be tested with guaiacum and dioxide before the stain is applied. (6) Action of Solvents and Other Reagents.—Stains upon cloth may be cut out and suspended in a test tube con- 74 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. taining distilled water. The bottom of the cloth should dip into the water, but the stain should not touch the sides of the tube. Under these circumstances the color- ing matter of blood will usually detach itself from the tissue and fall in reddish striz to the bottom of the tube. When a solution of blood is heated the color disappears, but vegetable colors in general are unchanged by heat. A solution of blood is made a little darker by the addition of a small quantity of ammonia, but the color is not de- stroyed. The red, pink, or scarlet infusion of fruit or flowers or roots and the juices of fruits are changed to green or violet by ammonia, and cochineal is changed to crimson. Hypochlorous acid quickly destroys all organic coloring matter except blood, which withstands the acid much longer. ‘Two minutes are sufficient to destroy most colors except that of blood. Stains of colcothar and grease and those of rust resist for a long time the action of hypochlorous acid, but disappear instantly on contact with chloride of tin, which does not act upon the color- ing matter of blood. Carbon mixed with the colored fluid cannot be readily discolored by any reagent. If the stains are upon weapons, from which it is im- possible to detach a superficial layer, they may be moist- ened with drops of water. If they are upon wood, plastered wall, or stone, we may scrape the surface and test the materialremoved. If upon the point of a dagger or other narrow blade, this material may be placed in a tall, narrow vessel. In general, if the material of the stain can be scraped off, the fine powder thus obtained may be treated with a minute portion of fluid in a test tube, watch glass, or on a concave slide or cover glass, such as is used with the microscope. The method of dealing with minute specks, when these are all that can be obtained from a stain, will be described further on. If the powder obtained is abundant and contains foreign matter, it may be placed in a small gauze bag and sus- pended in a test tube as described above. If the stains are spread in streaks on the surface of the instrument, a plate of glass may be adjusted on a perfect level, and a few drops of distilled water placed on the glass; then the instrument should be so arranged that the stain touches the water while the instrument does not touch the glass. After one or two hours the water will be colored by the stain; but whatever process we employ, it is important to avoid contact of the water with the steel or iron so as to form rust. In all cases only a small quantity of water should be used, and if the liquid contains much foreign matter it should be filtered before using reagents. 3. CRYSTALLINE PROPERTIES.—Crystals characteristic of blood were discovered by Teichmann, and great im- portance is attached to this test. To obtain hemin crys- tals, digest the stained tissues, or the powder obtained from the stain, ina one-fourth-per-cent. solution of com- mon salt for twenty-four hours, next allow the fluid to dry on a glass slide at a temperature of 80° or 100° F., and then apply a drop of glacial acetic acid, heating it over the flame ofalamp. As the fluid evaporates a great number of crystals appear, in the form of rhomboidal plates with angles of 55° and 125°, of yellow, red, or brown color, de- pending on the thickness of the crystalline plates. In the dog and in man they are long parallelograms. In the squirrel they are hexagonal plates; and in the guinea-pig they are in the form of tetrahedral crystals. The length of the crystals from human blood is from one and one- half to three times the breadth. They are generally very small, and if obtained from minute stains their obtuse angles are somewhat rounded, as are the crystals of uric acid found in the brick-dust sediments of urine. The microchemical examination of stains to produce hemic crystals, or crystals of hematin, or Teichmann crystals, when only minute stains are to be examined, is so important that we deem it desirable to give the fol- lowing directions, which we have translated from “ Précis de médecine légale,” by Ch. Vibbert: “The Teichmann crystals are so characteristic that when once seen they are ever afterward easily recognized. The operations for obtaining them are exceedingly simple. but require great care and patience. To avoid failure, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. persons but little accustomed to these minute investiga- tions should follow carefully the methods here described, especially if, as often happens, only minute portions of the suspected material are available for these researches. “(a) Solution of the Stain.—lf the stain is small and no speck or clot that may be removed can be seen, cut out the stain, following the edges of it, witha pair of scissors; place the stained piece of cloth on a glass slide, and put Fic. 607.—Hzemin Crystals. on it a few drops of water—just enough to moisten it, for it is better to get a solution somewhat concentrated. After macerating till the liquid is considerably colored, press Out the liquid with a scalpel or needle, and remove the cloth, leaving the colored fluid on the slide. Avoid spreading the liquid, but dry it slowly, so that it shall make a small, deeply colored spot on the glass: not en- tirely opaque but somewhat transparent, so that the preparation can be examined with the microscope. “Tf the stains are very small, several may be taken and macerated together to obtain sufficient coloring matter for the subsequent manipulations. If the stain is on wood, a thin layer of the wood may be removed by a sharp knife or lancet, and treated as directed for a fragment of cloth; only the maceration should be continued much longer. “Tf it is not possible to lift the stain from the object, a ring of wax may be formed around it, making an in- closure that will hold a little water, which is then ap- plied to absorb the stain. When the water has absorbed the coloring matter, it may be transferred to the slide by means of a pipette. “(b) Hvaporation of the Liquid.—We may allow the liquid to evaporate spontaneously, but the evaporation can ‘be hastened by the employment of heat, it being necessary, however, to heat the liquid very moderately, not exceeding a temperature of 60° C. (140° F.); for if the heat is sufficient to coagulate albumen, it prevents the extraction of the coloring matter, and of course no crystals will be obtained. We generally warm the slide over the flame of an alcohol lamp, being careful that the temperature does not exceed that which is not uncomfortable when the slide is laid upon the back of the hand. It is important to heat the liquid around the borders and not in the centre, so as to prevent its spread- ing over the slide, which would much interfere with sub- sequent operations. ; ‘ “(c) Action of Reagents.—To the evaporated residue a little common salt should be added. Too much is in- jurious. It is better to make a solution of 1 part of chloride of sodium to 500 or 1,000 parts of distilled water, and add one or two drops of this solution. Jt 7s more convenient to use this solution in the first place for dssolv- ing the stain, instead of using simple distilled water. It saves time and nothing is changed. Sometimes crystals Blood Stains, Blood Stains, can be obtained by treatment with acetic acid without the addition of salt, there being sufficient chloride of sodium in the blood; but it is better to add the salt than risk a failure in an important case. “At whatever stage the process the chloride of sodium has been added, the preparation must be thoroughly dried afterward before the acetic acid is applied. This acetic acid monohydrate is called glacial or crystallizable. It solidifies at the freezing point, or zero Centigrade, and does not again liquefy until the temperature is raised to 17°C. The addition of a small quantity of water trans- forms it into acid hydrate, which interferes with this re- action. “Place a drop of acetic acid monohydrate on the preparation and evaporate with heat, which may be in- creased and continued, though the evaporation will be more successful if the heat does not quite reach the boil- ing point. When there is only a small quantity of the suspected material, it is especially important to use all these precautions. The acid should be taken up with a tube drawn out to a fine point, so that only a very small drop may be added at a time; place the droplet in the centre of the red deposit on the slide, and allow it to spread a little, but not to spread beyond the limit of the stain; for this purpose the heat of the lamp should be ap- plied around the borders at various points, tipping the slide as may be necessary to retain the fluid on the red de- posit only; a red line is thus formed about the borders when the coloring matter becomes thickened, and the acid remains on the stain till evaporation is completed. It is on this border that the crystals are commonly formed, and they are to be looked for by aid of the microscope. “It is not common to find crystals after adding only a single drop of acid, but it is generally necessary to add drop after drop, evaporating each with the greatest care, examining the specimen from time to time where the red lines are formed one after the other as it is repeatedly treated with acid and dried. When this experiment is performed under favorable conditions, a multitude of distinct crystals are found. Often, however, we find only irregular masses of brown or dark coloring matter, and the remainder of the preparation filled with coagu- lated albumen and foreign bodies which have become mixed with the stain. If we have added solid particles of chloride of sodium to the coloring matter, we are apt to find crystals of this salt formed in cubes, in stars, or in small, colorless globules, and even lance-shaped crystals of acetate of sodium may be formed. All of these crys- tals, arranged together in beautiful forms, may often be found. “In such cases, we select a point where the coloring matter is collected in considerable quantity, and there apply another small drop of acid and let it evaporate as before. By repeating this operation we sometimes obtain a large collection of very small crystals mingled with other matter; but when we find crystals in the form of a cross or a star, it is very certain that they are chloro- hydrate of hxematin, and we may perfect the preparation by the addition of small drops of acetic acid. “Tf doubt still remains in regard to the nature of the crystals, the specimen should be examined by the aid of polarized light. The albuminous or saline substances allow the field to remain dark, but the crystals of hematin appear bright on a dark field. “By carefully following the precautions stated above, one can almost always obtain crystals of hematin, even with a very minute quantity of blood. The reaction is successful with very old stains. Many experts have ob- tained crystals of hematin from stains of blood ten, fifteen, and even forty years old. It sometimes happens, however, that it is impossible to obtain crystals when the stains are only a few months old. This is especially the case when the blood has been allowed to putrefy be- foredrying. Contact with perspiration, grease, or tannin also seems to interfere with the formation of crystals. “Two sources of error are to be noticed in connection with this test for blood. Crystals of murexide (purpurate of ammonia) have a form very similar to that of crystals 75 Blood Stains, Blood Stains, of hematin, but they are of a bright red, and they ac- quire a violet color by contact with a solution of potash; again, itis very difficult to imagine how it can be possible to obtain crystals of murexide by treating a stain with common salt and acetic acid. A mistake may easily occur with crystals formed with indigo. Cloth colored with this material will sometimes furnish a deposit of crystals which will not dissolve in acetic acid and which have a form very similar to that of crystals of hematin. Their color is blue, it is true, but when the color is very deep it can scarcely be distinguished from brown. Des- coust, by simply washing with water a piece of flannel of blue violet color, obtained crystals having almost ex- actly the form and reddish-yellow color of crystals of hematin. This isa more serious source of error than is generally admitted in books on legal medicine. “When a stain to be examined is found on clothing colored with indigo, it is important before examining the stain itself to examine pieces of the garment which are not stained, to see whether they will deposit crystals of indigo. The comparison between these crystals and those obtained from the stain may remove all uncertainty . if, for example, the crystals obtained from the stain are very numerous, while those obtained from the unstained cloth are very few and of a blue color. If the similarity of the two species of crystals is very close we may try the guaiacum test. The crystals of hematin will color the guaiacum blue, while those of the indigo will have no effect upon it. “When the crystals of hematin have been obtained they may be indefinitely preserved by adding a little glycerin and covering the preparation with thin glass. The expert should carefully preserve the preparation, to serve as a proof of the correctness of his conclusion.” 4, SPECTRUM ANALYSIS OF BLoop Starns.—One of the most important methods of distinguishing solutions of blood stains from those of other colored fluids is by the use of the spectroscope. The peculiar spectra produced by the passage of light through solutions of blood were noticed by Hoppe in 1862, and were suggested by him as a means of medico-legal research. Stokes, in 1864, and Sorby, Lethby, MacMunn, and others have added largely to our knowledge of this subject. The coloring matter of fresh blood is known as heemo- globin, and, according to Preyer, it contains nearly all the iron of the blood. By the action of reagents, such as acetic, tartaric, and citric acids, the bright red of fresh blood becomes changed to brownish red, known as heema- tin. This is a permanent chemical change. The same change of hemoglobin into hematin takes place when blood has been kept for a long time. ‘The fresh blood stain is bright red (hemoglobin); the old stain is brown (hematin). Hemoglobin and hematin are each capable of existing in two states of oxidation, each state produc- ing in the spectrum its own characteristic absorption bands. If a blood stain is kept in a damp place the hemoglobin is rapidly changed into hematin, or both hemoglobin and hematin may be decomposed. But if the stain is kept dry, it becomes in time of a brown color, This change is hastened if the stain is exposed to a strong light. This brown coloring matter is methemoglobin, which Sorby regards as peroxidized hemoglobin. This alteration is much more rapid in an atmosphere contain- ing coal gas, or a trace of sulphurous or any other weak acid. The change is also very rapid when a stained garment is worn next the skin, as the acid perspiration hastens the change. If the color of a blood stain be a bright red it is evident that it isrecent, but if it be brown it is not necessarily an old stain. When fresh blood, or a solution from a recent stain, is placed before the slit of a spectroscope, two dark absorption bands are seen be- tween the Fraunhofer lines D and E, the line near D be- ing darker, narrower, and more sharply defined than the other (Sp. 1-1, Fig. 609). Ifthe strength of the solution is increased the bands grow wider and the orange and blue are gradually obliterated. Ifthe strength of the solution is diminished the line near E first fades away and then the line near D also soon disappears. If the stain 76 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. has been changed to brown by the action of the air the coloring matter becomes peroxidized, and the solution then gives a single band between the positions of the two above described (Sp. 2-2, Fig. 609). The coloring mat- ter giving the single band is known as methemoglobin. Alkaline Hematin.—Make a saturated solution of car- bonate of potash in alcohol and pour a few drops of blood or solution from a recent stain into the solution. The color immediately changes, and when examined in the spectroscope a broad, lightly shaded band is seen covering Fraunhofer’s line D. Caustic potash and caus- tic soda in alcohol when added to blood give the same spectrum, but different from that produced by aqua ammonize or by carbonate of potash. It consists of three bands, one in the red, the other two like the bands produced by fresh blood. In the addition of a reducing agent the spectrum of reduced hematin appears, con- FIG. 608.—s 8, Solar spectrum; b b, human blood spectrum; d d, didymium spectrum; ¢ c, carmine spectrum; p p, potassium: permanganate, sisting of two bands similar to the bands of fresh blood, but removed farther from D toward the blue part of the spectrum, In Fig. 608 are shown at s-s the Fraunhofer lines of the solar spectrum. Below are shown the spectra of dif- ferent colored fluids: J-b, human blood; d-d, nitrate of didymium, of a faint pink color, in solution with lines similar to those of blood but easily distinguished from them; c-c, carmine solution, and p-p, tue spectrum of a solution of permanganate of potash with three dense lines and one very faint inthe red. All the spectra were pho- tographed on the same scale. All the fluids were illumi- nated by the electric light, and the right half of the spectra shows carbon and other lines produced by the flame of the carbon electrodes. Many more might be presented, but these specimens are given to illustrate the marked distinction, as shown by the spectroscope, be- ween blood and other colored fluids. Instruments for Spectrum Analysis of Blood Stains.—As the absorption bands produced by colored fluids are broad and not very sharply defined, an instrument of much less dispersive power than that used for colored flames is required. The microspectroscope made by R. and J. Beck, to be attached to the microscope instead of the objective, is very useful when the quantity of colored matter is considerable, as it allows the use of the mi- crometers in the eyepiece of the microscope to mark the Blood Stains, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood Stains. G VITALI HOHAA Om Oe OO It “eth aye panels Eevb HH | Meee ||| Ws) 2. aa ge ee aS ae = bee c- S BEE aes ess ip FP /ATPPertinenl FPPerFPPrl nnnnTno PO PPP Pom tn OP 700 1 | 2 k eee} 7 g a Fig. 609.—Spectometry of Blood. 17 Blood Stains. Blood Stains. position of absorption bands. When the quantity of coloring matter is small, ora mere speck of clot moistened on the slide is to be examined and tested, the objective, as low a power as practicable, is to be retained in the microscope and a microspectroscope inserted instead of the eyepiece. The Sorby-Browning microspectroscope in place of the eyepiece has been used for this purpose, but with this instrument it is very difficult to get the light from the clot centred in the slit of the spectroscope. The microspectroscope made by Zeiss, of Jena, is in- serted in the microscope in place of the ordinary eyepiece, and the direct vision prism can be turned to one side and by opening the slit the object on the stage of the micro- scope can be found and focussed; then when the prism is replaced the absorption bands are seen. It has also a side stage where a comparison specimen of blood or other fluid can be placed and its absorption bands compared with those of the object on the stage. It also has a micrometer scale illuminated by a side light by which the positions of the bands can be measured and records made, asillustrated in Fig. 609, M, 8. ‘With such a micro- spectroscope, under favorable circumstances, the absorp- tion bands can be seen in a single corpuscle of perfectly fresh blood, but not in a single corpuscle from a dried stain. But the bands can often be clearly seen in a speck of clot zi> or even 755 Of an inch in diameter when moistened with normal salt solution or with glycerin water. In the spectrum analysis of blood stains, careful comparison with known solutions of blood treated in the same manner may be made by placing the known solu- tion before the comparison prism, as in the Zeiss instru- ment, when any variation between the spectra placed side by side can be readily determined. For recording observations and results obtained it is im- portant to determine the wave length of the centre of every absorption band, noting the conditions and treat- ment of the stain by which it was obtained. To obtain wave lengths, each microspectroscope must have a micrometer of its own, with a scale of wave lengths carefully adjusted to the prisms and lenses used. Such tables and scales are shown in Fig. 609. Spectrum S-S shows the positions of the principal Fraunhofer lines of the solar spectrum. All the spectra in this figure or plate are drawn to the same scale, and the line D-D, from the top to the bottom of the page, is used as a start- ing point from which measurements are made and by which the position of the micrometer is adjusted. The didymium line, 6, in Sp. 10-10, is used in the same manner for fixing the position of the scale when artificial light is employed. The micrometer measurements may be reduced to wave lengths by means of an interpolation curve, shown at B, C, D, E, 6, F, G, constructed as follows: At the right hand is a scale of equal parts, numbered from 460 to 700. These numbers represent in millionths of a millimetre the length of all the waves of light which require to be considered in the analysis of blood stains. Across vertical lines, drawn through the Fraunhofer lines in the spectra 8 8, 8 8, horizontal lines are drawn from the scale at the right side of the plate at positions corresponding with the known wave lengths of the Fraunhofer lines. a = 718.5 C = 656.2 E = 526.9 F = 486.0 B= 68644 D= 5892 b = 517.2 G = 430.7 Through these points of intersection of the vertical and horizontal lines the curve B F is drawn. Then from points in this curve opposite to the numbers 460, 470 to 700, vertical lines are drawn, and these enable us to draw the scale W L, which serves to determine the wave length of any band measured by the micrometer M 8. The position of absorption bands thus determined may be recorded, and at any future time compared with the records of other observers. In Fig. 609, Sp. 1-1, at @ and }, are shown the ab- sorption bands of normal blood drawn in their relations to the Fraunhofer lines as seen in the Sp. S-S, and their true positions on the scale of wave lengths, W L. The band 2 is seen to be broader and paler than the band a. 78 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. In Sp. 8-8 are shown the absorption bands of an am- moniacal solution of carmine, where @ is shown to be paler than >, and also that > has a wave length 517 at its centre, while the band 4 in the spectrum of blood 1-1, 3, has the wave length 588.* The Sp. 9-9 shows the positions of the five bands in a solution of permanganate of potassa. In Sp. 5-5 the bands @ 6 ¢ are produced by a solution of alkanet, where the band a is almost exactly like a in tne blood spectrum 1-1, but 4 and c are different. If a little alum is added to the solution.of alkanet, the band d appears, while a } and ¢ remain unchanged; if alum is added to a solution of blood, both the bands disappear. At a, in Sp. 2-2, Fig. 609, is shown the band of reduced hemoglobin pro- duced when hydrosulphate of ammonia is added to a solution of normal blood. Other reducing agents produce the same effect. One of the best is made by dissolving equal parts of tartaric acid and double sulphate of iron and ammonia, and then adding a little aqua ammoniz. An ammoniacal solution of tartrate of protoxide of tin may be usedasareducing agent. It is prepared by add- ing tartaric acid to an aqueous solution of the protochlo- ride of tin, and neutralizing the solution with ammonia. The acid should be added in such quantity that after over-saturation by ammonia no precipitate is formed, but a clear solution remains. Sulphide of sodium is highly recommended by Preyer as a reducing agent. Dr. Beale recommends, as a de- oxidizing solution, protosulphate of iron, with sufficient tartaric acid added to prevent precipitation by alkalies. A small quantity of this solution, made slightly alkaline by ammonia or carbonate of soda, is to be added toa weak solution of blood in water. Ata, in Sp. 3-3, is shown the band peculiar to acid hematin, wave length 640. At a, in Sp. 44, is the band of alkaline hematin, wave length 605. At a, Sp. 6-6, is shown the absorption band of a solu- tion of fuchsin, wave length 548. Ata, Sp. 7-7, is the band produced by a solution of eosin, wave length 517. All absorption bands vary in intensity and in breadth as the strength of the solution varies, but the centre of the band remains stationary. At abe, in Sp. 10, are shown a series of beautiful bands produced by a solution of sulphate of didymium. This remarkable substance, of a faint pink hue, in solution almost as colorless as water, gives a broad ab- sorption band a, central ata wave length of 575 millionths of a mil'imetre, extending from 571.5 to 578. The line bis very sharply defined at wave length 523 of the same scale. This substance serves as an index to fix the posi- tion of the micrometer scale when using artificial light. Besides the substances mentioned above, some other red solutions give absorption bands somewhat similar to that of blood, but with careful manipulation and ap- propriate tests they may be certainly distinguished from blood. The coloring matter of the petals of the red variety of Cineraria, a variety of chlorophyll, gives two bands somewhat like that of blood, but the micrometer readily shows that they occupy different positions on the scaleof wave lengths. Add ammonia, and the blood bands remain unchanged, while those of the Cineraria solution are altered or completely destroyed. A solution of cochineal in alum: gives the bands a 3, Sp. 8-8, Fig. 609, differing little from those of fresh blood. Add ammonia, and in both solutions the bands become more intense. Now add excess of boric acid; in the solution of cochineal the bands shift toward the blue end of the spectrum, while in that of blood they remain unchanged. The other reds likely to be confounded by the un- practised eye with blood are lac-dye, alkanet, madder red, and munjeet, dissolved in each case in alum. But if the spectra be carefully examined side by side with blood, or their wave lengths determined on the scale * The scale of wave lengths are in millionths of a millimetre. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood Stains, Blood Stains, by their positions seen on the micrometer, it will be ap- parent that the bands produced by these bodies are not the same, either in position orin character. Further, none of them will stand the action of ammonia, while they are all bleached with sulphite of potash, which has no action on blood. In the examination of a mixture of magenta and blood, the magenta bands may entirely mask those produced by blood. The various blood spectra may, however, be easily obtained unmixed by adding to the solution a trace of sulphite of soda, which com- pletely removes the magenta coloring matter, but leaves the blood untouched. All the supposed fallacies disappear if we successively obtain the various blood spectra with the reagents al- ready described. Examination of a Recent, or Comparatively Recent, Blood Stain on a White Fabric.—(1) If you can detach a portion of the blood, do so; but if this is impossible, cut out a small piece of the stained fabric, and soak it for about ten minutes in a few drops of cold distilled water in a watch glass. Then squeeze the colored fluid out and set it aside for a short time, so that any insoluble matters may be deposited. Provide a glass cell about one-eighth of an inch in diameter and half an inch high, which may be made of a section of barometer tubing cemented to a slide with gutta-percha, with a diaphragm of tin foil between the slide and the end of the tube. With a fine drawn pipette introduce the red fluid into this cell, and place it on the stage of the microscope with an objective of low power, and illuminate with sunlight or other strong light, when, with the microspectroscope in place of the eyepiece, if the solution is blood the characteristic absorption bands will readily be seen. If there is a sufficient quantity of the solution, several tubes may be filled. If the tube contains any sediment, it may be laid to one side until the solution is clear. The ob- jective should be focussed near the top of the tube, a little below the surface of the fluid. If the blood is tolerably recent, the spectrum of oxidized hemoglobin with its two well-defined absorption bands in the green will be apparent, as shown in Fig. 609, Sp. 1-1. If such a spectrum is obtained, it is evident that it has been very little changed by exposure, and that it is probably of recent origin. If the spectrum contains two faint bands in the green, and an extra band in the red, it in- dicates that the stain has undergone a change. Now add a trace of ammonia to the solution in the tube, stir- ring it with a platinum wire, when you will obtain two bands in the green and none in the red. (2) To a second tube of the suspected solution add, first, a very little ammonia, and then a small quantity of Rochelle salt. With this no change will be produced in the spectrum, the ordinary bands being visible as before. Now add to the liquid in the cell a piece (about one- fortieth of an inch in diameter) of the double sulphate of protoxide of tron and ammonia ; stir the solution with the platinum wire, with as little exposure to the air as possible. Cover the cell with a piece of thin glass. The two bands seen previously will have disappeared, and will be replaced by a single intermediate band, fainter but broader than either of the other two, Sp. 2-2, Fig. 609. This is the spectrum of reduced hemoglobin The same effect will be produced by a trace of solution of sulphide of ammonium The specimen of hemoglobin thus reduced may be again and again oxidized by exposure to the air and vigorous stirring with the platinum wire It can be again deoxidized by further addition of the iron salt, or by sulphide of ammonium, if that was previously em- ployed for deoxidation This deoxidation and reoxidation of the hemoglobin is a very characteristic reaction, and serves to distin- guish blood from most other substances. If the solution of blood is merely covered with thin glass and kept for some time in the cell, the reduction of the hemoglobin will be effected spontaneously, and without the addition of any reagents. A question may arise here, whether this spectrum can possibly be due to iron. The question is at once an- swered by the fact that hydrosulphide of ammonium produces the same result, as also does the tin solution described on page 78, only that it acts more slowly than the iron salt. (3) Add to another portion of the suspected solution, in a cell, a minute fragment of cztrie acid, stirring it thoroughly with a platinum wire. The acid will change the hemoglobin into hematin. If previous to the addi- tion of citric acid the two bands of oxidized hemoglobin were visible in the green, they will disappear, and if the solution is tolerably strong a faint band will be visible in the red (Sp. 3-3, Fig. 609). Add now an excess of ammonia, by dipping the plantinum wire into the am- monia solution and stirring the moistened wire imme- diately into the liquid in the cell. The band in the red, if present, will now disappear, the original bands either not being restored at all or restored only to a slight ex- tent. This isa most important change to note, since it shows that the acid has effected a permanent change in the original coloring matter of the blood. Add now to the solution in the cell a very small particle of the double sulphate of iron and ammonia, and cover the liquid over immediately with thin glass. Remove the excess of liquid with blotting paper, and in order to ex- clude air it is advisable to fix the glass cover on the cell with gold size. Turn the cell over and over again, for a few minutes. In cold weather the process of oxida- tion is slow, and even a quarter of an hour may elapse before it is complete. By this means the hematin will be reduced, and two well-marked bands will be seen, the one nearest the red being the first to appear, and both being a little more distant from the red than the bands of fresh blood. If the solution be very turbid, the precipitate may be allowed to collect on the side by keeping the tube for a short time ina horizontal position. Preserve and mark the specimen for further examination if necessary. By exposing this solution of deoxidized hematin to the air, assisted by vigorous stirring, we may often succeed in bringing back again not only the oxidized hematin band, but also the bands of oxidized hemo- globin. (4) Lastly, add to some of the liquid under examination a small quantity of boric acid. If the solution be blood, no immediate change will be observed in the position of the bands. The above-mentioned method of examining blood stains of recent origin requires some modifications in special cases. Old Blood Stains or Blood Stains on Oolored Fabrics.— If blood stains are old, the coloring matter will probably be found to be scarcely at all acted on by cold water, Either citric acid or ammonia must then be used for dis- solving it. If the fabric be white, ammonia should be employed in preference to citricacid, but if it be colored, test, first of all, which of these two reagents has the less action on the dye-coloring matter, and then use that one, for the purpose of dissolving the blood, which acts less on the color of the cloth. To determine this, place a little of the fabric in two watch glasses and apply a solution of ammonia to one and a solution of citric acid to the. other In general, ammonia should be used in prefer- ence to citric acid. but in the case of red fabrics ammonia. will generally dissolve so much of the dye stuff that subsequent investigations with the colored solution are rendered much more troublesome and complicated. Hence, if the stain be found on scarlet cloth or other red material. citric acid should be used as the solvent. If the stain be found insoluble both in ammonia and in citric acid, then it should first of all be acted on with ammonia solution and a moderate heat afterward applied. Proceed then with the solutions in the manner already described, examining them with the spectroscope both before and after deoxidation with the iron salt. The age of a stain does not in general interfere with the spectroscope test, as Mr. Sorby has been able to discover: hematin with the spectroscope after forty-four years, and others have done the same after thirty years. 9 Blood Stains, Blood Stains, The presence of mordants on various materials may necessitate occasional alterations in our proceedings. More particularly will this be the case if the stained fabric has been afterward wetted and the blood by this means to a great extent removed. What blood remains on the cloth is then very likely to be incorporated with the mordant. Insuch cases a proc- ess such as the following should be adopted: Digest a portion of the stained cloth in dilute ammonia, and afterward squeeze out the liquid. Deoxidize the thick, turbid, unfiltered solution in the ordinary manner and examine it for the deoxidized hxematin bands, using con- centrated sunlight, or the lime-light if necessary. It is to be remembered that in the case we are suppos- ing the hematin is probably chemically combined with the mordant; hence filtration, or allowing the deposit to subside, is equivalent to removing most of the blood- coloring matter. The turbidity of the liquid must be overcome in such cases, not by removing the deposit, but by increasing the intensity of the transmitted light. Examination of Stained Fabrics that have been Washed after Staining, and the Treatment to be Adopted in the Examination of the Water that was used for Washing Them.—Hematin is a very insoluble body. Probably, therefore, after an article stained with blood has been washed in water, provided a sufficient time has elapsed for the change of the blood-coloring matter into hematin to be effected, enough will be left on the stained cloth to produce the spectra necessary for its identification. But it must be remembered that if the stain be perfectly re- cent, that is, before any of the hemoglobin is converted into hematin, the whole of the blood may then be washed out by rinsing in cold water, and no trace be afterward found on the stained material. Hot water will not effect this removal of the blood like cold water, owing to its further action. Hence, if in a criminal case there is proof that an article has been washed in cold water, evi- dence as to the absence of blood stains is of little value; while if, after staining, the article was washed in hot water, the probability is there will be no difficulty in satisfactorily proving the real character of the stain. In many cases, after a stained fabric has been washed, the blood stain will be found spread over a considerable surface. Under such circumstances a large piece must be cut out, and digested with a proportionately large quantity of ammonia, or of citric acid solution, the liquid being concentrated afterward by evaporation at a gentle heat. The water used for washing such materials may have to be examined. This can be done by concentrating the liquid, if necessary, and examining it in the usual man- ner If, however, it is found that there is any deposit in the water, it should be carefully collected, acted on with ammonia, and heat applied if the blood be insoluble in the cold solution. If the recently stained fabric, however, be washed with soap and water, hemoglobin will be rapidly con- verted by the action of the alkali into hematin. Soap and water, therefore, really sets the stain, and the proba- bility is that, after washing, there will be little difficulty in detecting it on the fabric itself by the ordinary means. It may be necessary sometimes to examine the soap and water to see if it contains blood. This may be done as follows: Agitate the soap and water with ether and allow the mixture to stand until the ether has completely sepa- rated. Remove the ether with a pipette, and again and again shake the liquid up with ether until the aqueous solution is perfectly clear and free from soap This liquid must then be concentrated, and examined as usual for blood Examination of Stains on Leather.—Blood stains on leather, or upon any body containing tannic acid, require special management on account of the precipitation of the coloring matter which is more or less certain to re- sult. Proceed as follows: (a) Cut off a fine shaving from the stained portion of the leather, so that there may be as much blood and as little leather as possible on the shaving. Bend this 80 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. shaving so that the side that is stained may be brought into contact with a little water placed in one of the ex- . perimental cells, while the leather side of the shaving is not wetted. In this manner solution of the blood will probably be effected, and enough coloring matter ob- tained for experiment. Mr. Sorby points out, however, that when a drop of blood falls on leather, the serum soaks into the leather, and leaves the blood corpuscles on the surface. If the leather be then washed, it would probably be impossible to obtain the blood spectra by the method just described. The following process, recommended by Mr. Sorby, has been found to work satisfactorily : (o) Digest, for a considerable time, a portion of the stained leather in a mixture of one part (by measure) of hydrochloric acid and fifty of water. This will effect a solution of the mixed compound of the blood-coloring matter and tannic acid. Pour off the acid liquid, but do not filter it. The solution may appear almost colorless, or of a slightly yellow tint. Add to this an excess of ammonia, when the color will become either a pale pur- ple or a neutral tint, the tint shade being considerably intensified on the addition of the ferrous salt and double tartrate, which are now to be added. The solution is then to be examined in an experimental cell, using a sufficiently intense light, such as the lime-light, or direct sunlight, to penetrate the turbid solution. Under these circumstances the spectrum of deoxidized hematin will be seen. If the liquid be too turbid to allow even a direct ray from the sun to be passed through it, allow the cell to remain for a few minutes in a horizontal posi- tion so that a little of the deposit may subside, although if this can possibly be avoided it is desirable to do so, because it will be found that the removal of the deposit at the same time destroys the intensity of the spectrum, proving that the greater part of the hematin under these a our exists as a compound insoluble in dilute acid. Before commencing the experiment with the stained portion of the leather, it is advisable to make out clearly how large a piece of the unstained leather may be treated . with a given quantity of the acid without producing too — dark a solution, and to take care afterward not to em- ploy a larger piece of the stained portion of the leather than is justified by these trial experiments. Blood Stains on Earth and on Clothes soiled with Earthy Matters.—The stained earth is to be carefully collected and digested in a considerable quantity of ammonia. This is to be poured off, concentrated by evaporation, and the spectroscopic experiments conducted as usual on the turbid solution, an intense light, such as the lime- light or direct sunlight, being used for the purpose, in the manner already described. A similar process should be adopted in examining stained fabrics soiled with earthy matters. This is important to note, inasmuch as the coloring matter in a solution of blood will be found to be completely carried down by earthy matter when shaken up with it. General Precautions to be Observed in Conducting Micro- spectroscopic Observations.—We now add a few words of general advice and a few precautions necessary to be observed in examining blood stains by the spectroscope. (1) If the fabric on which the blood stain occurs be colored, always examine the spectrum produced by the coloring matter alone, taken from unstained portions of the fabric. Further, it is well to put a little blood on an unstained portion, and to examine its spectra when dry, and thus fully determine, before commencing ex- periments on the stained portion, any possible interfer- ence in the blood spectra resulting from the presence of such coloring matter. (2) On no account decide that an observed spectrum from a suspected stain is due to blood unless it exactly coincides with bands produced by a known solution of blood of equal strength treated in a similar manner and examined side by side. It is advisable to have several tubes of the deoxidized hematin of different strengths for purposes of comparison These solution are best REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood Stains, Blood Stains, kept in hermetically sealed tubes, so as to have them at hand whenever they are needed. (3) In all cases examine the spectra both by daylight and by artificial light. We prefer artificial light for general work, but in every case it is advisable to try both means of illumination. Direct concentrated sun- light, or the lime-light, should be tried whenever the solution is thick and turbid. (4) Never be content with observing a single spectrum of blood. Remember, further, it is often impossible to obtain the unaltered blood spectrum. Hence never satisfy yourself that a stain is not blood until you have failed to obtain all the spectra produced by the appro- priate reagents. (5) If the liquid under examination be too strong, too much light will be cut off by the solution, and the absorption bands will be in this way obscured. If the solution be too weak, the bands will be too faint, and so likely to be overlooked. Practise in this matter to obtain the happy medium. Never (if possible) be satisfied with a single examination. ; (6) Use extremely minute quantities of the several re- agents. Hmatin produced by an acid is not very solu- ble in a strong solution of citrate of ammonia. If you add too much protosulphate of iron the precipitate pro- duced so obscures the field as to mask the absorption bands. (7) Adjust the width of the slit during the spectroscopic examination. Allabsorption bands are best defined when the slit is very narrow, while, if the bands are very faint, they will often be best seen at the very moment when the slit is being completely closed. (8) Remember that, with our present knowledge, the spectrum microscope affords no information whatsoever as to whether the blood is from man or beast, nor from what class of animals it is derived; nor, if it be human blood, does it enable us even to hazard a conjecture as to the locality of its origin. 9. Lastly, unless the stain is bright red—an appearance which can be noted only on white or nearly colorless fabrics—never venture an opinion as to the probable age of the stain. Of the certainty of this method of research, Mr. Sorby says (Medical Press and Circular, May 31, 1871): “I un- hesitatingly say we can distinguish blood (by the micro- spectroscope) from all other animal and vegetable color- ing matters.” 5. MicroscoricaL EXAMINATION OF BLooD STAINS.— Besides the fluid portion of blood, certain organized bodies are found, called corpuscles, consisting of two varieties, the white and the red. In the higher animals the red corpuscles are the smaller but the more numerous, while the white ‘corpuscles are rather larger and somewhat granular in structure and of a spherical form. The red corpuscles are circular, biconcave discs, of soft viscid matter, mostly soluble in water, but only very slowly dissolved by serum and the fluid part of the blood. The outer part of the red corpuscles is of firmer consistence than the interior, especially in the older corpuscles, but there is no special envelope or cell wall. By the action of water the coloring matter may be dissolved out, leav- ing the form of the corpuscle but little changed, except that it becomes nearly spherical. When blood is spread upon glass, or any hard non- porous substance, the corpuscles adhere and retain their diameters unchanged, but when blood dries in a clotted mass, the red corpuscles shrink and often assume a crenated or stellate form. If the stain to be examined is a mere film on a steel instrument or other smooth, hard substance, as glass or varnished wood, it may be laid on the stage of the microscope, and with a quarter or one-eighth inch objec- tive, with Beck’s patent illuminator above, the light of a lamp may be reflected down through the objective. In this manner the stain may be examined as an opaque object. By this method the writer has succeeded in recogniz- ing and measuring blood discs, magnified fourteen hun- dred diameters, on the blade of a knife which had lain in Vou. II.—6 the forest, covered with leaves, through two winters. Generally blood stains form a mass too thick to be ex- amined by this method, yet even then the corpuscles contracted to dimensions much below normal may be recognized as blood by this method of examination. If the stain is in the form of shining scales, or if it is on cloth, leather, or any porous substance, it may be picked off with a needle or pointed instrument, and the dust or particles of clot received upon a glass slide and moistened witha suitable fluid to separate the corpuscles and restore them to their normal dimensions. Fluids used in the microscopic examination of blood corpuscles should be such as will not destroy them, and such as will not increase or decrease their dimensions beyond their normal size. For this purpose a fluid should generally be used having the same specific gravity as blood serum, 1.028 or 1.029. Robin's fluid consists of distilled water, to which is added chloride of sodium, one per cent., and bichloride of mercury, one-half of one per cent. Roussin’s Fiuid.—Glycerin, three parts; sulphuric acid, one part; with water sufficient to reduce the specific gravity to 1.028. Hayem’s fluid consists of distilled water, with the ad- dition of sulphate of sodium, twoand one-half per cent. ; pure chloride of sodium, one-half per cent., and bichlo- ride of mercury, one-fourth per cent. Professor J. G. Richardson employed water with the addition of common salt, three-fourths of one per cent. Dr. Thad. 8. Up de Graff, who was very successful in distinguishing the blood of man from that of the lower animals, employed water with bichloride of mercury, one-half of one per cent. Many other microscopists use glycerin and water, mixed in such proportions as to give a specific gravity of 1.028. Each of the fluids described has some advantage over the others. The fluids containing bichloride of mercury are not likely to be infested with fungi when specimens are kept for a length of time. Glycerin water interferes less with other tests which may be applied after the microscopie examination is completed; but in this respect it has no advantage over Richardson’s salt solution. Filtered serum from the blood of a frog may be em- ployed in examining stains supposed to be from mam- malian blood. Albumen of egg is also sometimes used. In moistening blood stains with any fluid whatever it is to be remembered that the substance of the stain ab- sorbing the fluid renders it more dense than it was when prepared; therefore, if the fluid employed has no greater density than blood serum there is no opportunity for the blood corpuscles of the stain to enlarge beyond their ordinary dimensions in normal blood. As yet no fluid has been described which will cause dried blood cor- puscles to swell up toa greater diameter than the original fresh blood. When by the action of water the red cor- puscle becomes spherical, its diameter is diminished. When a blood stain is situated upon paper more of it remains on the surface than when the stain is upon cloth, and, after the paper is moistened, the film of blood can sometimes be detached from the surface in small scales or lumps. Mingled somewhat with filaments of the paper, and with molecular material, we find blood glo- bules more abundant than in stains upon cloth. The form of the globules is also better preserved, and they are often seen in nummular masses, as in fresh blood, and we recognize the central depression and dentate bor- ders characteristic of corpuscles of mammalian blood. These masses also preserve the color which distinguishes blood from all colored objects of vegetable or mineral origin. ‘ Stains upon wood have characteristics similar to those of stains upon paper. Stains upon woollen goods are somewhat more diffi- cult to determine than those on cotton, linen, paper, or wood. If we use the sulphate of soda solution for the ex- amination of fresh stains (not more than six days old) 81 Blood Stains, Blood Stains, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. upon iron or steel, the fibrin separates and leaves the corpuscles floating free in the liquid, and the clot shows the characteristic fibrillar arrangement. We find also the white corpuscles either isolated or entangled in the clot. The white corpuscles are no less characteristic than the red by their size, form, finely granular appear- ance, and nuclei, which appear near the centre, brought into view by the sulphate of soda solution. This solu- tion acts upon the white corpuscles almost as quickly as pure water, but causes them to swell less. The char- acteristics which distinguish white blood globules from pus should be noted whenever there is a possibility of finding the two together, which is not common in legal cases. If blood stains have been deposited on rusty iron or steel, or have remained long on such instruments even if not rusty, the glycerin solution is much to be pre- ferred in their examination, as it does not act upon the metal; while sulphate of soda or any of the acid solu- tions cause the deposit in the preparation of dark gran- ules formed of a salt of iron. The fine dust obtained by scratching a stain with a needle point or by crushing a large particle picked off from a shining clot, should be covered with a circle of thin glass, and a drop of one of the solutions described above should be allowed to run under the cover. If the stain is recent, it will be in a condition for examination in a few days, or in some cases in a few hours. If the stain is old, over six months, a much longer time is re- quired to soften it. If the object is only to recognize blood corpuscles when the dust-like particles have been softened, the fluid may be drawn away by touching one side of the cover glass with blotting paper, at the same time placing a drop of a staining fluid—as a watery solu- tion of eosin or iodine—on the opposite edge of the cover. Aftertwoor three minutes the colored fluid may be withdrawn in the same manner, and salt solution or glycerin water allowed to take its place, when the blood corpuscles, if any exist, will be easily distinguished, and may be measured by the use of the micrometer. Where a stain on paper, leather, or blades of grass is so thin that no particles of clot can be removed, Prof. F. B. Wyman, M.D., hardens the stain in formalin or in equal parts of alcohol and ether for five or ten minutes, then stains in a watery solution of eosin, dehydrates with al- cohol, clears in oil of bergamot, and mounts the paper, leather, or grass in Canada balsam as ordinary sections of tissue are mounted. The blood corpuscles of the stain are then clearly seen and can be measured. If the stains are not very recent, provision must be made to prevent evaporation of the fluid used to soften them. Takea glass slide witha circular excavation in the middle, called a “concave centre,” and moisten it around the edges of the cavity with glycerin. Thoroughly clean a glass cover an eighth of an inch or more larger than the excavation, lay it on white paper, moisten the centre with the glycerin solution (sp. gr., 1.028), drop- ping into the solution so placed the dust obtained from the stain, then invert the slide upon the thin glass cover in such a manner that the glycerined edges of the cavity on the slide may adhere to the margins of the cover; turn the slide face upward, and examine with the micro- scope. In the fine dust thus moistened, isolated red and white blood corpuscles will often be seen immediately. Tf not, lay the slide face downward on a suitable sup- port, and examine from day to day until the corpuscles become visible and cease to enlarge. They cannot ex- ceed their normal size when treated by this method. Prof. Joseph G. Richardson, M.D., made a minute dot of glycerin, about the size of this period (*), on a thin glass cover, and pushed into it a particle of suspected blood clot, the smallest that can be seen by the naked eye, one-thousandth or one-five-hundredth of an inch in diameter, receiving the cover on the concave slide as described above. By this method he obtained a strong solution of the coloring matter of blood, in which the absorption bands peculiar to blood could be seen, if blood was present in the stain; and by a little practice the 82 bands may be modified by the addition of sulphuret of sodium, as advised by Preyer and Sorby. By a similar method, using a little more material on a cover glass moistened with a very small drop of three- fourths-per-cent. salt solution, he was able to see, first, the absorption bands of blood with the microspectro- scope, then, turning the slide so as to drain off superflu- ous fluid, and using the microscope with a magnifying power of about two thousand diameters, he was able to see and measure both white and red blood corpuscles, so as to distinguish human blood from the blood of the ox, pig, horse, or sheep. In examining a slide prepared by either method above mentioned, if the material is blood, we first observe that the edges of the solid particles gradually become trans- lucent and the fluid around assumes a reddish-yellow color, showing that the coloring matter is soluble. In this condition of the preparation by use of the micro- spectroscope the characteristic absorption bands of blood will be seen. After a little time, if the amount of fluid applied be sufficient, the solid particles are softened, and, as they swell up, yellowish-white corpuscles with a slightly granular structure are seen; these are the well-known white blood corpuscles, which, with a magnifying pow- er of one thousand diameters or upward, may be dis- tinguished from other organized structures of either animal or vegetable origin. After longer maceration the characteristic red corpuscles of blood, with smooth and sharply defined edges, begin to appear, and after a time are found floating free in the fluid under the cover glass. If the stain is mammalian blood, some of the cor- puscles will be clearly seen as biconcave discs with a light centre and a dark edge or border. If any doubt remains in regard to the nature of these corpuscles, it may generally be resolved by the use of a higher magni- fying power. Grains of pollen may be generally distin- guished by a roughened edge, or by small points on the surface. Spores of fungi are often found mixed with blood stains, but in general the texture is different from that of blood. Occasionally the biconcave structure of red blood corpuscles can be distinguished, as a slight motion causes some of them to roll over as they move across the field. Unicellular alge, often seen in wet preparations, may be distinguished by the granules which they contain, having a greenish-brown or reddish color. These are grainsof chlorophyll. Spores of fungi growing in fluids have generally, if undisturbed, some systematic arrangement not found in the positions as- sumed by blood corpuscles. Erdmann records a case (Zettschrift fir analyt. Chemie, ii., 1862, and Gazette Hebdomadaire, quoted in Edinburgh Medical Journal, October, 1862, p. 370) which shows the importance of employing more than one kind of test in examining stains supposed to be blood. “The only trace of an assassination at Leipsic was a brownish stain found at the spot where the crime had been committed. Under the influence of rain, the stain had assumed the appearance of coagulated blood. An aqueous solution of this stain furnished a reddish fluid, which gave with tannin, with ferrocyanide of potassium, and with Millon’s solution,* the same chem- ical reaction as the aqueous extract of dried blood. Ex- amined under the microscope, the brown matter was found to contain some corpuscles very similar to those of blood. But Erdmann having failed to discover crystals of hemin, conceived doubts as to the value of the other characters, and repeated with great care the microscopical examination. He then discovered that the bodies supposed to be blood globules were the spores of alge called porphyridiwm cruentum, on account of the resemblance of its spores to blood corpuscles.” This blood-colored gelatinous alga, porphyridium cruentum, growing upon moist ground, is of doubtful * Millon’s solution is a strongly acid (nitric and nitrous) solution of proto- and pernitrate of mercury. made by dissolving metallic mercury in its weight of strong nitric acid with the aid of heat.—Micrographie Dictionary. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood Stains, Blood Stains, occurrence in the United States (Am. Quar. Mic. Journ., April, 1879). Thudichum, in “Tenth Report of Med. Officer to Privy Council,” 1867, p. 216, mentions a red, gelatinous mass, growing upon a human thigh-bone, which was macerating at St. Thomas’ Hospital. The glass vessel in which it was macerating was similarly covered. The microscope showed the red material to consist of minute cells in a gelatinous mass, with which larger green cells were interspersed. The water filtrated from them contained a number of minute bodies in sus- pension, It was red, and gave a spectrum very similar to that of blood. The plant in question is called by Thudichum red saprophytes. To avoid mistaking alge or other organized bodies for blood corpuscles, the guaiacum test, the heemin-crystal test, and the spectroscope should be used. The mammalian corpuscle, in its normal condition, is a delicate endosmometer, taking in or giving out fluid according to the relative density of the liquor sanguinis and contents of the corpuscle, allowing rapid variations within certain limits. Accordingly, .the corpuscles may be either swollen, puckered, or shrunk into a variety of figures, flat, tumid, like a shallow circular or oval cup, stellate, notched, granulated, mulberry-shaped, crescen- tic, angular, lanceolate, fusiform, or comma-shaped, or they may possess other figures defying description. In certain of the cervide the angular, crescentic, and lan- ceolate corpuscles are abundant. In connection with disease, deformed corpuscles are also found. The recognition of blood stains, and the probable de- termination of the animal from which they came, de- pend on the use of solvents of the same endosmotic power as the serum of normal blood, and on the micro- scopic examination and measurement of the corpuscles having thenormal form. Inthe blood of birds, fish, and reptiles having red blood discs of an oval or ellipsoidal form, it is sometimes possible, when they are standing on end or are distorted by drying, to see them as circular bodies. Time must therefore be allowed for the stains to be fully softened and the corpuscles to be isolated by the solvent before their origin can be decided. There are also some round corpuscles mingled with the elliptical, but they are too few in number to mislead a careful observer, Stains formed by menstrual blood contain uterine and vaginal mucus mingled with cells of epithelium. At the commencement of menstruation the linen is stained of a brown color, changing gradually to red. About the third day blood corpuscles are abundant, mingled with leucocytes and epithelium. The cessation of the courses is marked by the diminution of the red blood globules and the increase of leucocytes, rendering the flow more nearly purulent. Menstrual blood does not differ from any other blood, except that it is mingled with mucus and epithelium and an abnormal proportion of leucocytes, and that fibrin is almost entirely absent. The absence of fibrin is the most characteristic distinc- tion of menstrual blood. Blood Stains compared with Stains formed by Lochiat Discharges.—Medical experts are often called, especially in cases of infanticide, to distinguish between stains of blood and those formed by the lochiz. These stains are to be examined by the same methods as are available for stains of normal blood. In the lochial discharge, about six hours after delivery, we find about five leucocytes to one hundred red blood corpuscles. At the end of the first day only about one-third of the organized structures are red blood corpuscles. The leucocytes are nearly equal in number to the red corpuscles; pavement epi- thelium from the vagina is also abundant. Among the cells are some spheroidal or somewhat polyhedral by reciprocal pressure, united in groups similar to the deeper layers of epithelium of the vagina or neck of the uterus. The liquid, more or less viscous or odorous, which holds these elements in suspension, is studded with grayish granules. On the second day the leucocytes increase in number and the red globules diminish, and little by little the lochiz assume a russet tint, which on the third or fourth day passes into a grayish white or yellow. From the fifth to the seventh day, varying in different subjects, the red corpuscles almost entirely disappear, and the leucocytes become decidedly granular. Pavement epithelium is still found, but less abundantly than during the preceding days. The epithelial scales are generally imbricated, coming off in patches. The gray molecules become more adhesive and abundant, and the fat granules diminish innumber. Fibro-plastic, fusiform bodies with- out a nucleus, pale and transparent, are also found. This composition of the lochize continues without much change until the close of the flow. By these character- istics stains of lochial discharges can generally be dis- tinguished from normal blood. The blood of all animals contains certain organized structures called corpuscles. In all mammals except a few of the camel tribe the red corpuscles, which are the most numerous form, are circular biconcave discs of which there are in man from four to five million in each cubic millimetre of blood. Another form nearly spher- ical, called white corpuscles, of which there are about ten thousand to the cubic millimetre, havea nucleus and vary greatly in numbers in different stages of the digestive process and in different conditions of health. It is with the red corpuscles that we are principally concerned in the study of blood stains. In birds, fishes, and reptiles generally the red corpuscles are ellipsoidal and have a nucleus. By these differences Fig. 611.—Blood of a Snake. Fia. 610.—Blood of Lamprey Eel. of form it is easy, when using the microscope, to distin- guish between the blood of a mammal and that of all other animals with two or three rare exceptions. In the blood of some of the camelidze we find ellip- soidal corpuscles, but those can rarely if ever come into consideration in medico-legal cases. In the lamprey eel we find circular corpuscles with a nucleus; and these, again, are not likely to be mistaken for the blood of man or other mammal. On page 85 we give exact reproduc- tions of photographs of the blood corpuscles of man and of the principal domestic animals, magnified 2,560 di- ameters, with a scale in which each division represents half a micron or about one-fifty-thousandth (sg$59) of an inch. We thus see that when viewed by the high powers of the modern microscope wide differences are found be- tween the blood of man and that of such animals as the pig, horse, ox, sheep, and goat. In the blood of any single animal there are small and large corpuscles giving a considerable range between the smallest and largest in the same blood, while the general average of the corpuscles in man is greater than it is in any of the other animals whose blood is shown in the engravings. The accompanying table shows the range 83 Blood Stains, Blood Stains. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. and general average, measured in microns, for man, dog, pig, horse, sheep, and goat: TABLE SHOWING VARIOUS SIZES OF RED BLOOD CORPUSCLES (MEASURED IN MICRONS) IN MAN AND DOMESTIC ANIMALS. Microns. Man. | Dog. | Pig. Ox. | Sheep.| Goat. 9 9, 9. 8. 8. 8. ar 2 8. . 1 iis 5 5 Me 14 4 7 21 6 q. 45 10 ’ 6. 56 15 1 1 6. 26 13 1 0 6. 11 19 0 0 6. 16 44 29 0 5. 5 19 16 0 5. 1 13 20 3 5. 1 17 if 9 5. 10 34 30 4, 6 19 38 4, 4 8 Th 4, 4 il 26 2 4, 3 12 11 3. 5 3 94 3 7 63 3.8 ne 24 3.00 48 6 Number of corpuscles*..| 200 200 200 200 200 200 MAXIMUM Sitesi eiiaeetas 9.31 7.85 8.39 6.77 6.77 4.31 Minimatiny = ese eters 6.89 5.46 3.85 4.46 3.85 3.16 IMGaN i itetn ceceeten ees 8.01 6.87 6.07 5.44 4.75 3.69 * These numbers (two hundred in each column) include all between the number in the left hand column opposite to which they are placed, and the number next above. In any specimen of blood we find corpuscles of vary- ing size, but a remarkable uniformity in the average measurements of blood from animals of the same kind. Some discrepancies appear in the tables of measure- ments of blood as given by different authors. The tables found in most works on physiology or on medical juris- prudence were made when the instruments employed and micrometers used were by no means as perfect as the microscopes and micrometers now available. The fol- lowing table has been prepared with great care. The measurements, with two or three exceptions, were made by J. B. Treadwell, M.D., with a 34-inch objective, magnifying about twenty-five hundred diameters linear, and a glass micrometer placed in the eyepiece. The blood was spread upon glass and quickly dried. The reduction and arrangement of the results as given in the table were performed by the writer of this article. The standard of measurement was a micrometer ruled by Prof. W. A. Rogers, of Cambridge, Mass., and care- fully compared with the standards procured at great ex- pense by the United States Government. MEASUREMENTS OF MAMMALIAN BLOOD. x 85) 2 | 28) 28 | of |e8| 3/48 Source of 3¢ z ER | Se ES c= a3 Ea blood. Bq 2S | &e| 82 |ae es\sa S2| 8 |40| sh] Bb] “| SIs g B3| = a |e | ae 5 men, ages 23 to y 5.773| 7.697] '7.78217.84517.884|7.902 a9 Yeaieec ees + 11,000] 7.9414] Sal Sirol Stile coaleotalt oes 5 women, 18 to 55 o+ § | 6.350] 7.825] 7.787|7.878!7.90117.913 9 BOBS teas 1,000) 7.927) ) g/937| 81152} 8.02617.99317.96317.950 infants, at birth, » PRY y ; RS [mate, 2 fet ooo] 7.9804 | 2881 AR) TReIT em S187 8 : 6.929] 7.747] 7.828|7.891|7.965|7.988 Boy, 8 years old.. t 200 7.983 4 9.160 B28 8.191 8.079 8,000 e; e 7.005| 7.658] '7.662|'7.'768|'7.85217. Man, 70 years old. |} 200) 7.916}| $2581 x torl sus|sa8| 980 15 persons, as t 3.0001 7 038 J 4.233] 7.658] 7.662)7.768]7.852|7.913 above ......s.+5 ’ ‘ 10.160| 8.298] 8.191|8.079/8.046 7.983 Blood stains (hu- t 1.000! 7.910 ; 5.570) 7.700) 7.728 man) restored.. 8 : 9.687} 8.189! 8.010 84 MEASUREMENTS OF MAMMALIAN BLOOD.—Continued. b Bs| 8 d|Sal oo. é| 3 EE| = |e: /22| o£ |o8|eslBE wn | Sea lar | ae | do | oo |'o Source of o$| S§ | BR) ob] eo |as| aa) we blood. Se| % | B8| &y| ae leples| se a8] & | "2 | 22] Bie ee B'S s a | m + a c : 4.618] 6.138] 6.445]6.52316.673 SO COPS, cicero vias 2,500 6.918 | 8.931 7.352 7.305 7958/7198 Guinea-pig, male, | 5. ‘ -309)|7.249)7.393 Bene ae | 200) 7.4764} 8-559] 8.608) ‘esoly eaalyese Woodchuck, fe-1]| 999) 7.299 : 5.387 7.043) 7.112/7.215)7.279 WN hoon Gansson or ) ohet as 8.467 7.528 1.374 7,351|7.282 Muskrat, male ... ¢] 200) 7.2834] 9391] 7.535) TssBlcasly ep . 2 rabbits, 1 white, | 499] 6.365 j 4.618) 6.196] 6.227]6.294|6.349|6.354 1 mixed........ : 8.082] 6.596] 6.48516.409/6.383|6.377 2 hares, 1 male, 1 400! 5.764 { 4.618] 5.367) 5.377|5.604|5.733/5.756 female seet, al! 7.120} 6.080| 6.049]5.863/5.779]5.772 Gray squirrel, 1 5.926| 6.366| 6.627|6.77416.823|6.927 femble anlese 400] 6.876 | 7-221] P2881 9070117 06017 604 16.006 Red squirrel, fe- 4.926] 6.227] 6.381)/6.496|6.592 nial aan 6.607} | S53] Gssl| o:so7le to0|bsae Striped squirrel, | 200! 6.753 | 5.887| 6.573) 6.647|6.701|6.747 female wus .s -2102 1-3466 1-2080 1-3483 TUIKCY ccsmshiee cus tes 1-2045 1-3598 1-1894 1-3444 DUCK arene seenies cere 1-1937 1-3424 1-1955 1-3504 PIGEON eee cannes oe 1-1973 1-36438 1-1892 1-8804 GOOKE Mace sieene celstestiee 1-1836 1-3839 AJAY one eieele cine eieeialstets 1-2347 1-3470 WOO mr cctemaatemiestierase 1-2005 1-3369 SpPalLO Weeds tie cakienione 1-2140 1-3500 (Oh Usama qo Sade 1-1763 14076 Reptiles— Tortoise (land) ......... 1-1252 1-2216 1-1250 1-2200 Turtle (green) oa. sci os 1-1231 1-1882 Boa constrictor ......... 1-1440 1-2400 1-1245 1-2538 WAIDERAN cet swneemia tee 1-127 1-1800 NAZAT Parane ctemeaine eis 1-1555 1-27 Batrachians— LOG sonce te tee Risse Sts 5.0 1-1108 1-1821 1-1089 1-1801 TOAA sen aasauk canes sme 1-1043 1-2000 Triton Shocen. cake een es 1-848 1-1280 PTOLCUSS ae tien easel are 1-400 1-727 Amphiuma tridactylum..| 1-863 1-615 1-358 1-622 Fishes— ED TOUlie asvssate teweisiece elepsie es 1-1524 1-2460 Perchlicc. torknaesinetue: 1-2099 1-2824 DiIKGie paca sae een ches 1-2000 1-3555 WGlicseunechcbceaoteseter 1-1745 1-2842 TEAMPLC ck teiwrere 16/116 a so ie Circular. | 1-2134 INCI CIOUIS Jee cise sete wis ecole taste || Matreinied 1-6400 7 86 From these tables it is clearly shown that a careful microscopist would not be likely to mistake the blood of a goat, sheep, horse, ox, or pig for the blood of a human being; or that of any animal having blood corpuscles with an average diameter less than 3,55 of an inch or 0.0063 mm. (6.38 microns). Concerning the possibility of distinguishing the blood of a dog from that of man, medical experts are in nowise agreed, a few contending that they can distinguish a re- cent stain of the blood of a dog from the blood of man, and they have successfully accomplished the task when put to the crucial test of experiment. The late Col. J. J. Woodward, M.D., when testifying as an expert in the Hayden trial, at New Haven, Conn., in 1879, stated that he had measured twenty corpuscles from a young dog, forty from another, and fifty from a third, in which he found the averages of the corpuscles measured from each one of those dogs larger than the recognized average size of human blood corpuscles. In regard to these measurements Dr. Woodward stated in his cross-examination, by the state: “J looked to find big corpuscles and I knew that the group around them would be large.” The same expert has published measurements of the blood of other dogs so large that he inferred that there is no safety in attempting to state positively that a given stain is the blood of man and that it could not be the blood of a dog. L. Perier has shown that the blood of new-born in- fants often contains giant corpuscles similar to the large non-nucleated corpuscles of the human embryo, and states that until recently these have not been considered as true red corpuscles. He also states that these giant corpuscles have a ten- dency to collect together, and that in estimating average measurements it is important to examine all parts of the slide on which the blood is spread. LL. Perier also says that he finds in the blood of infants many globulins nearly spherical, only about half the diameter of ordinary blood discs. If these globulins are not included in the measurement it will be easy to obtain large averages for the blood of infants. Dr. R. U. Piper, of Chicago, finds that the blood cor- puscles of new-born infants retain much of the character of pre-natal blood, and give an average diameter larger than that of the blood of adults. He also finds the blood of young puppies giving a larger average diameter than that of the blood of adult dogs, but these facts do not disparage the value of the microscope as a means of dis- tinguishing the blood of man from that of full-grown dogs, especially if we can obtain for comparison authen- tic specimens of the blood of the particular man and dog with which a given blood stain is to be compared ina given case. Dr. Thad. 8. Up de Graff (in 7’he Microscope, October, 1883) states that the red blood corpuscle of the dog re- sists the action of water and ruptures less readily than does the red corpuscle of human blood, because, as he thinks, the cell wall or border is thicker in the blood of the dog than it is in human blood. By a careful study of the micrometric data from which the table of measurements by Dr. Treadwell was calcu- lated I find as a general rule, to which there are some exceptions, that the blood corpuscles of young animals have a greater range (as Perier and Hayem have stated) from the smallest to the largest corpuscle, and a slightly larger average diameter, than have those of adults. This is shown in the case of a male pig, two weeks old, in the first table giving the range of two hundred corpuscles for that and other animals. The same is apparently true of the blood of females as compared with the blood of males. My own measurements of human blood of in- fants and adults, both male and female, tend to the same conclusions. ; In the measurements given in this table the whole of the dark border was measured. The measurements were originally taken and recorded in parts of the American standard inch, which have been reduced to parts of a millimetre by reckoning 1 inch = 25.40098 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood Stains, Blood Stains, mm. The measurements in the table are given in mi- crons, 0.001 mm, To secure a fair average two hundred corpuscles were generally measured, and often this number was meas- ured from several animals of the same class. To show how large a number of corpuscles should be measured to obtain a fair average, the range of averages is given as computed by tens, twenties, fifties, and hundreds; also the range of averages of two hundreds as taken from the separate animals. J. G. Richardson, M.D., of Philadelphia, during the progress of the Centennial Exhibition at Philadelphia, measured one hundred corpuscles from each of fourteen men of different nationalities, using a one-twenty-fifth inch immersion objective and a cobweb micrometer eye- piece; the microscope thus arranged magnifying eighteen hundred diameters. He found the average diameter of the fourteen hundred corpuscles to be inch gs4sz or 7.879 microns. This is smaller than the measurement given in Dr. Treadwell’s table, viz., 7.8988 microns. While the general consensus of opinion among micros- copists is that the blood of man can be distinguished with great certainty from the blood of such domestic animals as the pig, ox, horse, sheep, and goat, but few experts would venture any very positive diagnosis in criminal cases between the blood of man and that of the dog; though a correct diagnosis has been often given in experimental cases. Over twenty years ago Dr. Wood- ward published his results in the measurement of the corpuscles of dogs, giving averages which could not be distinguished from the measurements of human blood. Professor Wormley, Dr. Richardson, and Dr. Treadwell opposed his conclusions and sought opportunity (which was never given) to examine Dr. Woodward’s specimens of dog’s blood. At the famous Hayden trial before the superior court in New Haven, Conn., in 1879, Dr. Wood- ward explained his method of obtaining a large average of the blood corpuscles of the dog. He stated that he took blood from young dogs, spread on slides, and, looking over a slide till he found a collection of large corpuscles which have a tendency to collect together, he made his measure- ments from that collection. As asample of his work, Dr. Woodward stated that on December 14, 1879, he measured 50 corpuscles from a pup four weeks old, a Newfound- land crossed with a setter, and found the average was 326- millionths of an inch, or 8.28 of a micron. December 12, 1879, he measured, selected in the same manner, 40 corpuscles from a Scotch terrier and got an average of 320-millionths of an inch, equal to 8.18 microns. From a Gordon setter full grown he measured 29 corpus- cles and obtained an average of 300-millionths of an inch, equal to 7.62 microns. Dr. Woodward, when testi- fying under oath, said: “I desire to put myself on record as distinctly denying that those measurements of the dog’s blood would represent what you would be likely habitually to get if, without picking out young dogs and without selecting a spot to measure appearing to have unusually large corpuscles, you were to measure dog’s blood. You would then habitually get smaller figures than I have given here. The average of the corpuscles of dogs would habitually be smaller than I have given here, but I have purposely selected for fixed measurements young dogs, for I knew they had bigger corpuscles, and, in the second place, in taking an old dog, I purposely selected a place on the slide where, to my trained eye, I saw there was a group of big corpuscles. My reason for doing this is to show that if you pick up a half-dozen corpuscles by chance, you may chance on these big things. But I have nowhere stated that the average for the dog is as large as for man; on the contrary, I would like to read my express statement from my printed utter- ance, that the general average for the dog, for a great number of measurements, will be less than for a great number of men.” Dr. Woodward appeared to contend that in examining blood stains you might chance to get a small speck of dried blood, from a dog, having princi- pally these large corpuscles. Thisargument throws doubt upon any attempt to distinguish between the blood of man and that of the dog unless a large number of cor- puscles have been measured. In Figs. 619 and 6201 give examples of the blood of man and the blood of a young female pug dog, both photographed by me on the same negative. They are magnified only 640 diameters in order to include a considerable number of corpuscles in the comparison. In this case no attempt was made to select a place where large corpuscles had collected. I should not attempt to distinguish with any degree of confidence in a criminal case between the blood of man and the blood of a dog. As a difficulty in distinguishing the blood of different animals by microscopic measurement, Dr. Robert Ryburn (Medico-Legal Journal, September, 1892, p. 165) says, the trouble in our investigation of this subject lies in the fact that the blood corpuscles are living organisms that are not possessed of outlines delineated with mathematical accuracy. Replying to this objection we refer to Pro- fessor Wormley’s statement (“ Microchemistry of Poi- sons,” p. 728): “ Ina series of ten spaces ruled on glass measured by three observers with different instruments the results did not differ more than s5_555 Of an inch; and that two independent series of measurements, with high Fig. 619.—Human Blood. 640. FIG. eo hed of Pug Dog. X 640. powers, of 20 designated blood corpuscles were abso- lutely identical for 16 corpuscles, and for the other 4 the greatest difference was only spj559 Of an inch.” Still further, Professor Wormley reports the measurement of 7 human blood corpuscles, with powers from 1,150 to 8,500 diameters, by different microscopes, and by draw- ing with the camera lucida. The range of averages of the different measurements Was gs5q inch to ys45 of an inch as measured by the camera lucida. The mean of the averages being zs, of an inch; the same 7 cor- puscles measured by Dr. Richardson, using a cobweb micrometer, gave a final average of zs4, of an inch, differ- ing from the former average by something less than gzp\595 of an inch. To further show the certainty of determin- ing the exact limits of the border of the corpuscle and that different experts are likely to obtain the same re- sults, [ would mention that on a slide of human blood, irregularly spread, and dried so that the corpuscles on one half of the slide appeared larger than the other half, Dr. Treadwell measured, with high powers, 75 corpuscles on one side, showing the larger, and 75 on the side show- ing the smaller corpuscles. The average of the 150 cor- puscles thus measured was y_¢;7 of aninch. The writer, using a power of 1,400 diameters and a cobweb microm- eter, measured 50 corpuscles on one part of the same slide and 50 on the opposite part of the slide, and found the average of the 100 to be 3,45 of an inch, differing by only gsz}a77 Of an inch from the results obtained by Dr. 87 Blood Stains. Blood Stains, Treadwell on the same slide. The above reported results remove, as I think, all objections attributed to the personal equation of the observer or the supposed indistinct or woolly appearance of the border of the blood corpuscle. Prof. Marshall D. Ewell, M.D., LL.D., an excellent microscopist, in the Medico- Legal Journal, September, 1892, gives a report of very careful work in micrometry of 4,000 red blood corpuscles. He gives 9.06 microns as the average of 100 corpuscles from a boy thirty-six hours old, and 8.65 microns for another 100, or 8.85 microns as the average for 200 corpuscles; also the mean of 300 corpuscles from two puppies two days old as 8.22 microns, and that of 800 from a puppy eight weeks old as 8.48 microns. This report sustains the views stated above, that young animals have larger corpuscles. Pro- fessor Ewell shows by measurements of his own blood, taken on six different days, variations from 9.05 to 8.2 23 microns (the general average being 8.08 microns). This shows that for the same individual, while in health, the average of 100 or more corpuscles remains substantially constant. Professor Ewell further says: “(1) There are such large discrepancies between the averages obtained from the measurement of the fresh blood corpuscles of animals of the same species, and between the measurements of the same objects by different observers, as to throw doubt upon the published results. “In the use of the micrometric test no confidence can be placed in the results, unless the errors of the microm- eter used, with reference to some authentic standard, are known. “There is no advantage in using very high powers in such investigations.” (By this statement he probably means that there is no advantage in using powers above a one-twelfth inch or a one-eighteenth inch objective as he has done. In this view of magnifying powers most microscopists at the present day are agreed; but when he claims that measuring ruled lines with a one-inch, three- fifth inch, and one-fifth inch objective is as good as with the higher powers, few experts would agree with him.) “Many diseases alter the size of the red corpuscles; especially is this so in microcythemia. Fasting dimin- ishes both the size and number of the corpuscles. So also in the case of various drugs.” In view of the foregoing, according to the views of Professor Ewell, ¢¢ 7s ¢mpossible in the present state of sci- ence to say of a given specimen of blood, fresh or dry, more than that tt ts, or ts not, the blood of a manmat. As the paper by Professor Ewell has been extensively quoted, and as Professor Ewell is now the most promi- nent opponent of medical experts on blood stains, the above conclusions will be further examined. In regard to the micrometric test Professor Ewell’s criticism does not apply to comparative measurements of blood of different animals where the expert, using always the same micrometer, bases his diagnosis on his own measurements alone. At present, however, it is easy for the expert to obtain micrometers made by skilful work- men and carefully rated by comparison with a reliable standard. Yet it isa remarkable fact that the measure- ments of human blood given by Gulliver, in 1875, zs57; Wormley in 1885, ys;5; Schmidt, in 1848, -3,,;; French Medico-Legal Society, in 1873, zs:,; Masson in 1885, 3287} Hans Schmidt, in 1887, ss; Woodward, in 1875, so03; Formad, 3555 — made at distant intervals and with- out comparison by a common standard—differ by only one-half of the difference between the blood of man and that of the pig. If Hans Schmidt did not measure the dark border of the blood corpuscle it would account for the small average which he obtained. Another source of difference in measurement is in the mode of obtaining and preparing the blood for measure- ment. Ifa string is tied around the finger or the circula- tion is impeded in any other manner, and the blood is obtained by pricking with a needle, and is then spread upon a slide, the corpuscles, deprived of a portion of serum, will measure less than if obtained from a cut with a lancet where the circulation is not obstructed. 88 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. So also, if the blood is drawn from the prick of a needle ina warm and dry atmosphere, the corpuscles begin to contract before they can be spread upon a slip of glass. None of these considerations enables us to reconcile all the discrepancies noticed by Professor Ewell in the writ- ings of different authors; but the great fact is shown, by the unanimous consent of all microscopists, so far as we can ascertain, that less than 3,500 (most writers say less than 3,300) corpuscles of human blood are required to measure an inch, when placed side by side; while more than 4,000 corpuscles of the pig are required to measure an inch, and for the horse, ox, cat, sheep, and goat still more are required. Hence all authors agree that there is a remarkable difference between the average diameter of the human blood corpuscle and that of any domestic ani- mal except the dog. Taking the pig as the representative of domestic ani- mals, because its corpuscles are larger than those of the ox, horse, cat, sheep, or goat, the following comparison between the blood of the pig and human blood is very significant : To determine the extent of the possibility of mistaking the blood of the pig, ox, horse, sheep, or goat for human blood, we will examine ‘the table of measurements made by J. B. Treadwell, M.D., using a one-twenty-fifth inch objective made by R. B. Tolles, and Jackson’s eyepiece micrometer, made by Tolles, ruled by Professor Rogers, and a stage micrometer ruled, tested, and rated by Pro- fessor Rogers. In this table the measurements of 3,000 corpuscles are given, 200 having been taken from each of fifteen differ- ent persons. The measurementsare given maximum and minimum by tens, by twenties, by fifties, by one hun- dreds, and by two liundreds. Six hundred corpuscles | from pigs were measured: 200 from a pig three weeks old, 200 from one of two months, and 200 from a pig three months old. As the corpuscles of the pig have a larger average than those of the ox, horse, sheep, or goat, we make our com- parison between the blood of man and the blood of these three young pigs: Microns. Microns. Man, smallest ten.......... 7.658 Largest teMniccieaspaes 8.298 Pig te ae ee teens 5.418 : oO heteee 6. Man, Ma twenty...... 7.662 4) twenty ..... 8.191 Pig, oe a A er 7.768 2 pas ans 25.08 6.466 Man, “ Hifty:wecmeece 7.768 fs TIty some 8.079 Pig, om ORs dehrdeowe 5.880 od La Are onc 6.246 Mans = hundred,.... 7.852 ‘hundred 8.046 Pig, * Se seats O28: mK 6.169 Microns Smallest: ten from WAN shies woo 0 nis ale ocsis’e1s essinvese ein eae 7.658 Largest ten from! the Pigs ss << oc cibreiee tee crsie civ eieretere termine 6.520 DifOTenCe sais o/1d/s/b cleave Meicie biel eleie le cfolore Stele neietere ire nee 1.138 This equals 0.000045 of an inch = gz4zz inch. Smallest twenty from Man. cc deecce cccke crlscisine Clee name 7.662 Largest twenty from the pigs... vivccies be selec sane 6.466 DIMOTONCE Ss ..5:05 cs,s:e orosserie 4.08's bala eaielreleqarstaicle nt 1.196 This equals 0.000047 of an inch = sy37z, inch. Smallest fifty from man... < i.eescs eee ce atin wereeeetnee 7.768 Largest fifty from) the Dig’. 5 scence ccsieccalelererasatetelsion terete 6.246 ) b) bi) 9-) 1 1e: eRe AACR Ne Sanrio ns aoa And sec 1.522 This equals 0.000060 of an inch = ggg inch. Smallest, hundred from MAN 5.1. cslssniciastes wie ne ele Largest hundred from the pig........cccceccserevsesceees 6.169 Difference. (cess lantasalhc a cate csc aelavasee Cee eee eae 1.683 This equals 0.000066 of an inch = zg}¢y inch. We thus see that where only 10 corpuscles are meas- ured in man, taking the smallest average of 10 consecu- tively measured, this average for an adult man is one- sixth larger than the largest average of 10 consecutive corpuscles measured from a young pig only three weeks old; while the average of the smallest 100 from man, taken consecutively, is about one- -fifth, 7g, larger than the largest 100 taken from the young pig. Professor Ewell says: “Drying the blood éorpuaanten in a clot multiplies the difficulty of identification. It has never been proven that dried corpuscles can be restored to their normal proportions.” I would eall attention again to the table on p. 84 of REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood Stains, Blood Stains, ee eeesesesesoseseseseseeeee the present volume, which gives the measurements of 3,000 corpuscles of fresh human. blood, including males and females, of all ages, from infants at birth to the man of seventy. The measurements are in microns. Number of orpeee Aver-|Max.| By | By | By | By | By individuals. puscles. | 28°: Min. | 10s. | 20s. | 50s. | 100s. | 200s. 15 persons as haw \| 4.233] 7.658] 7.662 7.768] 7.852) 7.913 stated, | ¢ 3000 [7.998 | 4760 81298) 81191] 8.079) 81046) 71983 Phu ..|{ 1000 F.10j i bis B0 5.880] 6.028] 6.069 : "757| 5. Byoung pigs.|} 600 |6.101}| 3-4| 8:49u] 6 absl Gavel Gciool Grtae Here we see that the average of 1,000 corpuscles re- stored and measured from stains of human blood is 7.910 microns, all probably being stains from the blood of adults; while the average from fifteen persons (three be- ing infants) is 7.988 microns. The maximum, where in- fants are included, in fresh blood is a little more widely separated from the minimum than in the restored stains from adults. So also the range, when taken by tens or by twenties, is a little less for restored blood than for fresh blood, for the same reason. No closer similarity of re- sults could have been expected had all the measurements been taken from fresh blood; one set including infants and the other being taken from adults alone. The fact that there is this difference, as given above, goes to show the great accuracy and perfect restoration of dried blood corpuscles to their normal dimensions. As a further confirmation of the possibility of restoring dried blood stains to a condition in which their dimen- sions can be properly compared with fresh blood cor. puscles, I copy by permission the following table from Professor Wormley’s “ Microchemistry of Poisons.” EXAMINATION OF OLD BLOOD STAINS. 7 Fresh Animal. Age of stain. Remarks. we (1) Human .| 2 months old..} Stain, unknown .| 1-3358 (2) Human .| 2% “ a foi UIA see or eae ale 1-3236 (8) Human .| 3 a i Stain cccaeeses ve 1-3334 (4) Human .| 19 iy es ClOL Ree ence vite 1-3290 (5) Elephant | 13 a ClOD Perea Metaerttee 1-2849 (6), Dog..... 4 a Sy Trace of stain, unknown ...... 1-3626 1-3561 (7) Rabbit ..| 18 s * Clots ae woke: 1-3683 1-3653 AB )i OX cictee,s.0 16 eS Me Siginner crates 1-4544 1-4219 COWOK . cns s,s 32 oe * ..| Stain, unknown .| 1-4495 1-4219 CLOOX es 1: AVG VOATS les «tel C1Ob sc cteisteraartiee ele 1-4535 1-4219 Miiyeputtato.. | 18 Months =* V1 Clot... cececsae. 1-4312 1-4351 (12) Goat ....| 17 a eames OAL Tce a ciccitrtaee 1-5897 1-6189 Kis)iIbex::.;.. 18 ne Seda OLOL sce pare vreanaes 1-6578 1-6445 “In the case of the human blood No. 1, two months old, the deposit was in the form of a thin stain on muslin, and its nature, other than that it was mammalian blood, was unknown at the time of examination. The cor- puscles were readily found, and two series of thirty cor- puscles were measured. In the human blood two and a half months old, fifty corpuscles ranging from 5753 to ry; of an inch were measured. “The blood stain of the dog, No. 6, was prepared by Dr. Frankenberg, and consisted of a single stain so mi- nute as to be barely visible to the naked eye; its nature at the time of the examination was unknown. In this instance only fifteen corpuscles were measured. In the ox blood four and a half years old, the corpuscles were rather readily obtained, and two closely concordant series of measurements were made.” Another table, quoted by Clark Bell, Esq., in his article on “Blood Stains” in the Medico-Legal Journal, September, 1892, p. 157, is worthy of careful study in this connection. It shows results of examinations of blood dried on knives, glass, wood, cloth, paper, and stone, with measurements corresponding very closely with measurements of fresh blood. I take great pleasure in acknowledging my obligations to Professor Ewell, from whose valuable articles on micrometric study of 4,000 red blood corpuscles, pub- lished in the Medico-Legal Journal for September, 1892, I have compiled the following table: S¢/_,/ ¢] 4/28/28 Source of blood. B3il=8| & 5/28/88 23/9 5 | SR| ed BE|8S| 3 | 2 | eal] ee zS/S8| a | & |e" |B ROBUSGINEN secttats sitecien ones 650 | 8.03 | 9.98 | 5.08 | 8.28 | 7.95 Boy thirty-six hours old...... 200 | 8.86 | 11.89 | 5.70 06 | 8.65 FAG TTI ee Agan sGnnORrCOOe 100 | 7.85 | 9.82) 6.%¢ 60 Purpura hzemorrhagi¢ca....... 200 | 8.25 | 10.87 | 8.45 | 8.28 | 8.25 2cases pseudo-leucocythzmia| 400 | 8.04 | 11.04) 6.56 | 8.55 | 8.42 Tuberculosis, anzemic........ 100 | 8.385 | 10.70} 5.35 950 PlumbismMesicn seiscees come cess 100 | 8.65 | 10.10} 5.18 GaStritls ores unica cvewicle tives 100 | 8.82 | 10.18} 6.22 | ... aoe 2 cases Syphilis.............6 200 | 8.11 | 9.382) 3.97 | 8.11 } 8.11 YYSINCIAGS ciceniactceneniteeectes TOOT 7.83. eS ULGrRG: OO bie eel sane Pernicious anzwemia........... 100 | 7.69 | 9.93 | 6.04 MENSITUBI DOOM ss cess neces LOO FT B80 5.76 Whole number measured. .| 2,350 | 8.14 | 11.89] 3.45 | 9.06 | 7.95 In regard to the alterations of blood in disease, it is to be noted that no disease causing smaller average sizes of the blood corpuscles of the lower animals can have any tendency to cause such blood to be mistaken for human. If it was sought to ascertain whether a given stain, with corpuscles less than 3-55 Or giz Of an inch, could have been obtained from a diseased human being, found by examination to have very small corpuscles, such a case would be judged by the facts discovered and possi- bly be indeterminable. If we take 3355 of an inch or 7.987 microns as the gen- erally accepted average diameter of human blood cor- puscles, and with it compare the average obtained by Professor Ewell from blood in disease, we find his largest average in plumbism, or lead poisoning, is 8.65 microns, or one-twelfth part larger than the normal average. Now, if we take the young pig, which, excepting the dog, is the domestic animal having the largest corpuscles, and to the normal average, 6.101 microns, add one-twelfth its diameter, or 0.508 micron, we shall obtain for a pos- sibly diseased pig an average diameter of 6.609 microns; which is smaller by 1.318 microns than that of the average human blood corpuscle. This difference when viewed in the microscope with a magnifying power of 2,500 diame- ters, the same power used in the photographs reproduced in Figs. 612 and 613, is equal to more than two and a half divisions of the scale in Fig. 6138. With only 1,000 diam- eters the difference would be greater than one division of the same scale. Certainly no microscopist of ordinary skill would be in any danger of confounding blood of such a diseased pig with human blood recovered from a stain. The only remaining possibility of mistaking stains from the blood of a pig, ox, horse, sheep, or goat for human blood, when fifty or one hundred corpuscles have been measured and found to average 7.9 microns, or even 7 mi- crons, is to suppose it possible that the expert has wickedly and purposely measured only the largest corpuscles and has not done honest work. Witha magnifying power of 1,000 diameters, a Jackson’s micrometer measures with great certainty spo, Of an inch. Professor Ewell’s filar mii- crometer, as he states, is graduated to zoptnay Of an inch, and is certainly reliable to s5}55 of an inch, equal to one of the divisions on the above scale. Hence no ex- pert can have any difficulty in recognizing with absolute certainty differences of 1.3 microns, equal 3455 of an inch. Professor Ewell says that “by selecting the corpuscles, it would be possible for a dishonest observer to make the average much larger or smaller than the above given [in his table] without the possibility of detection; a fact, the bearing of which upon the value of expert testimony upon this subject is so obvious as to need no comment.” I have never claimed, and shall not now claim, that it is 89 Blood-Vessels, Blood-Vessels, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. any more difficult fora witness to swear falsely in regard to blood stains than in regard to any other subject. But it would be quite possible on cross examination to ask the expert whether, in measuring the corpuscles obtained from a stain, he had measured all the well-defined cor- puscles in the field of the microscope, or whether he had selected the large corpuscles and rejected others which were smaller, In treating blood stains with solvents of fibrin, to liberate the corpuscles for measurement, it has been found in many cases that the corpuscles were smaller than in fresh blood unless maceration was long continued, old stains requiring several weeks before the corpuscles were in a condition to be measured. When a biconcave blood corpuscle is placed in water, the coloring matter (hamo- globin) is dissolved out, the corpuscle swells up, thickens at the edges, becomes transparent and spherical. In this condition the diameter of the corpuscle becomes less than normal. It thus happens in examining blood stains that ail corpuscles which have lost their color or have become spherical are by some experts rejected and not measured. Some corpuscles in fresh blood have much more coloring matter than others, and these corpuscles retain their color and form (as we think) much longer than paler cor- puscles. We are not aware that any fluid used or likely to be used for softening blood stains will cause the cor- puscles to become larger than normal. In this statement the most noted authors agree. If the corpuscles obtained from a stain do not recover their normal dimensions it is almost absolutely certain that their average measurement will be less than normal and never greater than normal. Thus, in the language of Professor Wormley, we may confidently say: “ Thus, then, while the blood of man might on account of contrac- tions in diameter of the blood corpuscles be confounded with that of some animal having smaller corpuscles, the reverse could never occur.” From this discussion I claim that it has been proved beyond any reasonable question: 1. That in favorable cases blood stains can be so treated that reliable measurements and credible diagnosis of their origin can b: given,as shown in the tables given anl in others which might be “jia) tissue referred to. Internal elas- | 2. That if error tic membrane } occurs on account of imperfect res- toration of the form and diameter of the corpuscles obtained from a stain, proved (by (a) the guaiacum test; by (0) the spectroscope; by (c) the production of heemin crystals) to be blood, the error, if any, will be to make human blood appear like that of one of UNO Spears elas inferior animals, tic snaioneney and never to mis- take the blood of the ox, pig, horse, sheep, or goat for human blood. 3. In general, when a stain has been proved to be blood by the above tests, it may be decided certainly whether it is or is Endothelium Subendothe- t Involuntary t muscle Elastic tissue Fib1 0-elastic t tissue Vasa vasorum 90 FG. 621.—Section of Human Radial Artery. not mammalian blood. So, also, a stain from the blood of the ox, pig, horse, sheep, and goat may be distin- guished from human blood, thus confirming the claim of an accused person in many cases that his clothes are not stained with human blood. This negative testi- mony is certainly quite as important in many cases as testimony inculpating a prisoner. Lastly, the expert can say, when the average of a suit- able number of corpuscles from a blood stain corresponds with the average of fresh human corpuscles, that the stain is surely not from the blood of the ox, pig, sheep, or goat. Such testimony by a skilled microscopist is of untold importance in saving the lives of the innocent, and often in overthrowing the plea of those who are guilty. Such testimony is quite as reliable and important to the wel- fare of society as that of the chemist who testifies to the presence or absence of poison that might have some re- semblance to the many recently discovered ptomains. The testimony of the expert might take the following form, as recommended by C. H. Vibbert, “Précis de médecine légale”: “This stain is not composed of the blood of such an animal [ox, sheep, horse, pig, or goat] as the accused claims. It is like the blood of man, or some animal hav- ing corpuscles very nearly the same size as those of man, as the dog or rabbit.” Or the declaration may take the reverse form, thus: “This stain is 20¢ composed of human blood; it might be the blood of a horse, ox, pig, sheep, or goat, as claimed by the accused.” Such declarations are justified, then, and then only, when the examination has been conducted with great care and the measurements have been made with reliable instruments. Moses C. White. BLOOD-VESSELS, HISTOLOGY OF.—TxHE ARTE- ries.—An artery consists of three coats, which, named from their relative position, are the inner, the middle, » and the outer. The structure and relative thickness of these coats vary in vessels of large, medium, and small calibre. A medium-sized ar- tery, such as the radial, shown in the accompany- ing illustration (Fig. 621), has been taken as the type and first de- scribed in detail, the structural pe- culiarities of the larger and smaller vessels being sub- sequently noticed. The znner coat, or tunica intima, is the thinnest coat of the artery and consists of three distinct structures: (@) an endothelial lin- ing; (0) a layer of subendothelial connective tissue, and (c) an internal elastic membrane. The _ endothelial lining consists of a single layer of flat endothelial 5 Adventitia cells, each containing a centrally situated nucleus of round or oval form. When examined in a transverse section of the vessel, in which the cells are seen in profile, the endothelial plates are incon- spicuous, the nu- cleus often being the only part of the cell readily made out. Examined from the surface, after staining with silver nitrate, the boundaries of the individual cells are clearly defined by the darkly tinted cement substance which unites the endothelial plates. In such _ prepara- tions the lining cells appear spin- dle-shaped or lan- ceolate in form, their long axes cor- responding with that of the blood- vessel. Careful ex- amination of the outlines of the cell shows these to be serrated or sinuous, contrasting with the more regular lines of apposition in epithelial tissue. The lining cells of blood-vessels were first described by KOlliker and others as epithelium; later, His applied to them the name endothelium as more appropriate for elements de- rived from meso- derm and closely related to serous surfaces. In prin- ciple, endothelial cells are modified connective-tissue elements. The subendothe- lial layer consists of bundles of white fibrous connective tissue interwoven with a delicate net- work of elastic * fibres, and meagrely distributed branch- ed connective-tissue corpuscles lying within the lymph spaces of the tissue. The internal elastic membrane appears in arteries of medium size as a structureless, glistening, corrugated band that stands out as the most conspicuous structure It constitutes the most external layer of the latter and forms a sharp line of demarcation between the narrow and faintly stained intima and the broad and While apparently a homo- geneous membrane in the smaller arteries, in vessels of large size the internal elastic membrane is represented by a number of delicate lamell of elastic tissue, which are of the intima. more deeply tinted REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood-Vessels, Blood-Vessels, Endothelium Subendothe- lial tissue Internal elas- tic membrane Involuntary muscle Elastic tissue External elas- tic membrane Fibro-elastic tissue media. ' Foxx: Mm Fic. 622.—Section of Human Aorta. pends. oblique course. pierced by apertures of varying size. ture in these cases has been appropriately named the Jenestrated membrane of Henle, in recognition of the an- Intima Media Adventitia The entire struc- atomist who called attention to its pe- cullar arrangement. The majority of the elastic fibres form- ing this reticulated network run longi- tudinally, but are intermingled with some oblique fibres as well as a limited number of branched connective-tissue corpuscles. The middle coat, or tunica media, is the thickest coat of the artery. It con- sists of circularly disposed lamellz of involuntary mus- cle intermingled with connective tis- sue in which elastic fibres are conspicu- ous. The individ- ual muscle cells are irregularly spindle- shaped, often with ragged outlines, and possess the characteristic rod- shaped nuclei. The muscle cells of the media are shorter and thicker than the slender and more elongated cor- responding ele- ments in other localities. The in- dividual cells, held together by inter- stitial cement sub- stance, are grouped into illy defined bundles, which are closely associated with small spiral bundles of white fibrous and elastic connective _ tissue, the whole forming the most compact coat of the artery. The elastic fibres are very numerous, and, in ordinary preparations being almost unstained, stand out in mark- ed contrast among the more deeply stained masses of in- voluntary muscle. The external coat, or tunica adventitia, is composed of closely felted bundles of white fibrous and elastic tissue arranged in fine wavy masses. have a longitudinal direction, while others pursue an Connective-tissue cells are present in considerable quantity. While looser in texture and ap- parently of less strength, the adventitia is nevertheless more resistant than either of the other coats, and is the tunic upon which the integrity of a ligature chiefly de- The walls of the arteries are nourished by a Many of these bundles 91 Blood-Vessels,. Blood-Vessels. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. special system of minute vessels, the vasa vasorum, which enter the adventitia and penetrate the media. The vasa vasorum do not spring from the vessels which they sup- ply, but are usually derived from neighboring arteries, the blood flowing through the larger vessels having as a rule no direct relation with that within the vasa vasorum. The differences distinguishing the coats of a large artery from those of a vessel of medium size consist, in general, of an increase in the thickness of the various tunics, as shown in the accompanying Fig. 622. The immediate lining of even the largest arteries con- sists of a single layer of endothelial cells; the subendo- thelial tissue, however, is greatly thickened not only relatively but also absolutely. The subendo- thelial bundles of white fibrous tissue are coarser, and the elastic tissue is present in greater amount and constitutes the fenes- trated elastic membrane of Henle. The me- dia likewise is thicker, the increase, however, being due not so much to the greater amount of involuntary mus- cle as to the addition of fibro-elas- tic tissue, which here bears a much greater proportion to the muscular tissue. This increase of fibro-elastic tissue is responsible for the diminu- tion of elasticity and the increased stiffness which characterize the walls of the larger arteries. The clastic tissue of the media in the latter vessels is often condensed. to form an eaternal elastic membrane, which defines the boundary be- tween the media and the adventitia. The adventitia is also thicker, but the increase in this tunic is proportionately less than that affecting the in- tima and media. The adventitia of small arteries, in relation to the other two coats, is thicker than that of the large arteries. The small arteries and arterioles, on the other hand, differ from the medium-sized vessels by a reduction in the thickness of their coats. The subendothelial tissue almost entirely disappears, while the involuntary muscle of the media is reduced to an attenuated layer of muscle cells, with little or no admixture of fibro-elastic connec- tive tissue. Theadventitia consists of a few longitudinal bundles of fibrous tissue, with often an absence of elastic fibres. The capillaries are microscopic vessels establishing communication between the arteries and the veins. In Adventitia Capillaries { Nuclei of ~ endothe- ‘lial plates Connec- tive-tissue cells F1G. 623.—Capillary Blood-Vessels from Mesentery of Dog. X 240. the tips of the fingers, the tips of the toes, the tip of the nose, the splenic pulp, and the erectile or cavernous tissue of the genital organs the arteries communicate directly with the veins. A capillary consists of a single layer of 92 nucleated endothelial cells united by a small amount of intervening cement substance. By reason of the char- acter of their thin walls, they are virtually protoplasmic tubes admirably adapted to facilitate the distribution of nutritive fluids to the tissues or, as in the pulmonary alveoli, to the interchange of gases. As the capillaries become larger a delicate tunica adventitia is superadded, which is formed of a delicate network of fine fibrils, composed of the processes of stellate cells lying di- rectly upon the vascu- } Fibro-elastic tissue Elastic tissue } Involuntary muscle j Internal elas- tic membrane | Subendothe- lial tissue Endothelium Fic. 624.—Section of Human Radial Vein. lar walls. Each of these stellate cells consists of a large elongated nucleus, invested by an extremely deli- cate layer of protoplasm. The protoplasm of which the cells are composed is always more abundantly and distinctly granular toward the centre and around the nucleus, whilst near the margin it is quite clear, and thins off to a delicate border. The capillaries by their union constitute the capillary plexuses, vetéa capil- laria, Which are more or less constant in the different organs. The forms presented in these plexuses depend to some extent upon the disposition of the elementary parts, and are also in some degree dependent upon the energy of the function. There are in many organs cer- tain tissues into which vessels never penetrate,—as the transversely striped muscular fibres, the nerve fibres, cells of all kinds, gland acini,—and which, therefore, accord- ing to their form, trace out definite courses for the capil- laries, so that they sometimes present elongated meshes, sometimes rounded, narrower, or wider reticulations. The mode in which the capillaries pass into the larger vessels is interesting. On the arterial side it is found that the capillaries, as they become wider, present more closely placed nuclei, and are then invested externally witha structureless tunica adventitia and solitary muscle cells, the whole structure exhibiting the aspect of ar- terioles. On the venous side the transitionary vessels are less characteristic for a greater length. The first thing that is superadded, on this side, to the capillary wall is an external, homogeneous nucleated layer, which.may be regarded asa sort of connective tissue—the tunica adven- titia,—forming a distinctly laminated structure, the vein- iol. Besides the finest capillaries, which, bowever, al- ways admit the passage of very flexible blood corpuscles, some observers have admitted the existence of still finer vessels, the so-called vasa serosa, Which no longer allow of the passage of blood, but only of its plasma. Hyrtl thinks that it is necessary to admit of the existence of vessels of this kind in the cornea. Among the structural peculiarities of certain arteries. may be mentioned the slight development, or even com- plete absence, of the subendothelial connective tissue in the celiac, the external iliac, the mesenteric, the renal, and the uterine arteries of young individuals. The aorta. possesses a marked development of the subendothelial. ~ REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood-Vessels, Blood-Vessels, connective tissue, as well as the presence of longitudinal muscle cells within the intima. Longitudinally disposed muscle is present in the media of the subclavian artery and in the adventitia of the iliac, the superior mesenteric, the splenic, the renal, and the dorsalis penis, as well as in the umbilical arteries of the foetus. Some arteries, notably the vessels within the cranial cavity and the vertebral canal, possess coats which are very thin in proportion to their calibre. In these vessels, however, it is the media and the adventitia that suffer reduction, the intima re- maining almost unaffected. A typical vein, as shown in the accompanying drawing, (Fig. 624) has thinner walls and a larger lumen than the corresponding artery; to this rule, however, the pulmo- nary veins are exceptions, since they are of the same ca- pacity as, or of less capacity than, the pulmonary arteries. The constitution of the coats of a vein is less constant than it is in an artery, variations in the arrangement, propor- tion, and amount of the component tissues being very frequently encountered. The inner coat, or tunica intima, consists of (a) endo- thelial cells, (6) subendothelial connective tissue, and (c) elastic fibres. The endothelium is composed of a single layer of cells held together by interstitial cement sub- stance. The cells are shorter and wider than the corre- sponding lanceolated elements of the artery. The sub- endothelial connective tissue is very scanty in the majority of veins and rudimentary or even entirely absent in the smaller ones. The elastic tissue often represented by a few longitudinal bundles is less developed and does not form a fenestrated membrane. The middle coat, or tunica media, is much thinner and looser than in the artery, chiefly on account of the ad- mixture of connective tissue associated with the circu- larly disposed involuntary muscle cells. The élastic fibres, so conspicuous in the media of the artery, are very few in the vein. The external coat, or tunica adventitia, is the thickest coat of the vein, reaching often twice or even three times the breadth of the media. It consists of wavy bundles of white fibrous tissue, usually following a cir- cular direction, among which a few longitudinal fibres may be found; the greater number of the latter fibres are of the elastic variety, Connective-tissue cells are present in considerable number. The walls of the vein are nourished by vasa vasorum similar to those supply- ing the arteries. Many veins, especially those of the lower extremities, are provided with valves; these are crescentic folds of the intima, which are brought into apposition by the dila- tation of the pockets formed between the attached portion of the valve and the wall of the vessel. The valve con- sists of an extension and thickening of the fibro-elastic tissue of the intima, covered on each side by endothelial cells. The free edge of the valve is thicker than the at- tached border. The variations in the structure of veins depend largely upon modifications of the muscular tissue. The involun- tary muscle is best developed in the media of veins of the inferior extremities; in the veins of the gravid uterus involuntary muscle occurs in.the adventitia as well as in the intima. Additional longitudinally disposed bundles of muscle are present in the inner part of the media in the mesenteric, the iliac, the femoral, and the umbilical veins. Involuntary muscle is sometimes encountered in the ad- ventitia, in the abdominal cava, the axillary, the hepatic, ths external iliac, the superior mesenteric, the renal, the splenic, the spermatic, and the azygos major veins. The presence of striated muscle in the pulmonary veins and cardiac ends of the vene cave is to be regarded as an extension of the striped muscular tissue of the auricular wall. Robert Formad. BLOOD-VESSELS, PATHOLOGICAL ANATOMY OF. —TueE CAPILLARIES.—The capillaries are less independ- ent structures than the arteries and veins, and the pathological changes in the capillary wall are generally intimately connected with lesions in the surrounding tissues. The important rdle played by the capillaries in the different forms of inflammation is discussed in the article on Inflammation. All tissue proliferation, whether inflammatory or non- inflammatory, is almost without exception associated with the new formation of capillary vessels by processes of budding of pre-existing capillary endothelium, and these changes are described in the article on Regeneration. Capillary new formation lies at the bottom of tumors composed of capillaries, the capillary angiomata and teliangiectasias of congenital or acquired origin; they form mostly flat tumors of the skin and subcutaneous ° tissue, of a bright red colorand a soft feel; the capillaries in them have thick cellular walls, and there is abundant evidence that new capillaries have beenformed. Similar changes occur in capillaries in other tumors (see 7umors). Long-continued congestion will result in dilatation of the capillaries, capillary ectasis or capillary aneurism; this is shown well in passive congestion of the lungs. Hyaline degeneration of the capillary walls is frequently observed in the brain, especially in paralytic dementia, but also in the kidney, the conjunctiva, the lymph glands, and in various tumors. Hyaline degeneration of the glomeruli is an important alteration in chronic nephritis, especially the interstitial form. Hyaline degeneration is a rather vague term and the exact origin of hyaline ma- terial is not understood. In certain tumors mucoid de- generation of the capillary walls sometimes takes place. Mallory in his study of colloid or hyaline changes in the brain shows that the material is always deposited in the vessels; in the larger vessels the middle coat is earliest and most affected. The hyaline material has a marked tendency to calcification, and in some cases the capillary network of the central cortex, the dentate nucleus, and the granular layer of the cerebellum undergoes hyaline change with calcification; this causes atrophy of the in- cluded nervous tissue and leads to the formation of sand- like deposits and of stone-like concretions. Fatty changes in the capillary epithelium* occur fre- quently, especially in the nervous system and in the various toxic and infectious states. The lesions in the capillaries that may underlie the tendency to spontaneous hemorrhage in the hereditary and acquired hemorrhagic diathesis have not yet been cleared up; in these condi- tions it is difficult to determine whether the hemorrhages result from diapedesis or from rhexis. The relations of the capillaries to thrombosis and embolism are described in the articles dealing with those subjects. Calcareous infiltration of the capillary walls occurs in the brain of old people; generally calcification is pre- ceded by hyaline degeneration. Calcification of the capil- laries also takes place in certain tumors, especially psam- moma. Amyloid degeneration is an important change in the capillary walls, observed always in the capillaries of the spleen, kidneys, liver, etc., in general amyloidosis. The amyloid material appears first in the delicate capillary sheath outside of the epithelium, which is soon crowded to one side and the lumen closed. Tur ARTERIES AND VEINS. ABNORMITIES.—Congenital abnormities of blood-ves- sels may concern width, thickness of wall, origin, and course. Deviations from the normal in these respects on the part of the smaller and medium-sized vessels are con- sidered to best advantage in connection with the normal anatomy of blood-vessels. The congenital defects and anomalies of the pulmonary artery and aorta are closely associated with defects and anomalies of the heart. Among the important irregu- larities of the primary vessels is transposition of the aorta and the pulmonary artery. This may occur in hearts that are not otherwise defective or in association with other developmental anomalies of the heart. Transposi- *The term “epithelium” is used in place of endothelium in this article.—L. H. 93 Blood-Vessels, Blood-Vessels, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tion of the ven cave and the pulmonary vein is also described. In nearly all cases of this kind the foramen ovale is open to a greater or less extent and generally the ductus arteriosus is pervious. In some cases the only communication between the two circulatory systems was through the widely open foramen ovale. Death occurs in early infancy. The septum between the aorta and pulmonary artery may be defective. In an instance of this kind that I ex- amined there was an oval defect about 1.5 cm. in its greatest diameter between the pulmonary artery and the aorta, so that the beginning of the aorta and pulmonary artery had a common trunk from which emerged, in the usual places, the right and left pulmonary arteries and the branches of the arch of the aorta. The ductus arteri- osus was patent and large, the aorta distal to the duct wider than that proximal to the duct. The foramen ovale was widely open. The large veins and the heart were normal. Instances of aortas with double arches are described by Hommel, Curnow, Malacarne, Zagorski, Welch, and Lee Shaw. According to Lee Shaw, Hommel, in 1737, was the first to record this anomaly. In his case the two divisions united after encircling the trachea, and passed downward on the left side of the vertebral column. Malacarne’s report, as described by Meckel and Quain, differs from all the others. Five valves guarded the aortic opening of the left ventricle and the arterial trunk immediately divided into two branches, which before uniting embraced the pulmonary artery, trachea, and cesophagus; from each division was given off in succes- sion a subclavian, an external, and an internal carotid artery. In Welch’s case, the posterior branch passed be- tween the trachea and cesophagus, and from each division arose a common carotid and a subclavian artery. On the posterior branch was found an aneurism from which the right common carotid took origin. Lee Shaw’s speci- men differs from all of those described except Mala- carne’s, in that the two divisions unite behind the cesopha- gus. It differs from all in that the right branch is the larger, the junction of the two branches is on the right side, and the descending aorta passes downward on the right side, to the upper border of the eighth dorsal verte- bra. This arrangement not cnly resembles the vascular ar- rangementin the reptile, butalso more closely follows the distribution in the bird than it does that in the mammal. Such anomalies of the aorta are probably due to the persistence and enlargement of fetal vessels which nor- mally become obliterated. From the embryonal aortic bulb two vessels arch backward, one on either side of the foregut, forming the first pair of vascular arches, and de- scend along the sides of the notochord as the primitive aorte. As the heart gradually moves away from the head, four more pairs of vessels develop, which connect the bulb with the descending trunks; making in all five pairs of arches, one for each branchial plate. Zimmer- man describes an additional pair between the fourth and fifth. “The bulb, primarily a single cavity from which, through two common trunks, one on each side, blood is sent to all the arches, is divided by a septum parallel to its long axis into two compartments: one becoming the pulmonary artery, situated anteriorly, and continuous with the fifth pair of arches, the other forming the sys- temic aorta, placed posteriorly, and communicating with the fourth pair, through which all the arches above re- ceive their blood supply. Notwithstanding this separa- tion near the heart, both pairs of arches, 7.e., the fourth and fifth, ultimately empty into the descending aorta which has been formed by the coalescence of the primitive aorte. “This symmetrical arrangement of the vascular system is soon destroyed by the obliteration of certain vessels. Even before the last arch is perfectly formed the connec- tions between the first pair and the descending aortze may be destroyed. However, the fourth and fifth arches, lying nearest the heart and soon exceeding the others in size, are the chief factors in this transformation. The 94 vascular arches on the left side continue to increase in size and in greater part become permanent. while those on the right gradually become obliterated, except where they furnish the supply to permanent arteries. “On the left side the fourth arch becomes the arch of the aorta and, in the fcetus, is constructed between the origin of the left subclavian and the junction of the ductus arteriosus, forming the isthmus, which soon after the closure of the duct attains the diameter of the ad- jacent trunk. The fifth, on this side, forms a part of the Fic. 625.—Stenosis of Aorta at Ductus Arteriosus. Cruveilbier.) (Modified from left pulmonary artery and the ductus arteriosus, which is occluded soon after birth but remains as a round cord. On the right side the fourth arch is permanent for a. short distance as the innominate and right subclavian arteries, as far as the origin of the vertebral, beyond which it diminishes in size and finally disappears. Only a small portion of the fifth persists on this side as the root of the right pulmonary artery; the distal portion becomes obliterated.” In Lee Shaw’s case, the fourth arch on the right side not only remained patulous, but exceeded the left in size. The fourth arch of the left side retained some of its fetal characteristics, because it was doubtless unnecessary for the isthmus to enlarge after occlusion of the ductus. arteriosus, as the blood current could easily pass through the right arch. Premature obliteration of the ductus arteriosus has. been described as causing an abnormal smallness of the pulmonary artery. The pulmonary artery may divide at a point lower than usual, or arise by two distinct. roots, instead of continuing into the aorta as the ductus. arteriosus; it may form the left subclavian artery. Sup- plementary or vicarious branches distributed to the lungs. may arise from the aorta as far down as the ceeliac axis. In narrowing or obliteration of the aorta after having given off the vessels to the head and upper extremities, the inferior parts of the body are supplied with blood from the pulmonary artery through the ductus arteriosus; REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood-Vessels, Blood-Vessels, the descending aorta is said to be given off from the pulmonary artery. Now if the degree of constriction of the aorta be but slight at the time of birth, the ductus arteriosus may become closed. Later in life great nar- rowing and even complete obliteration of the aorta may take place (Fig. 625). The theory usually offered in explanation of the patho- genesis of this condition was first broached by Skoda in 1855. The narrowing is made dependent upon the pres- ence in the walls of the aorta of embryonal connective tissue connected with the ductus arteriosus; the post- natal involutional changes then lead to varying degrees of stenosis of the lumen of the aorta. Aberrant vestiges of duct tissue may occur in the aortic walls. Throm- bosis of the aorta beginning in the ductus arteriosus may end in complete aortic obliteration (Rauchfuss),. Of 1138 cases of narrowing and closure of the aorta at or near the opening of the ductus arteriosus studied by Wadstein, atresia was present in 20. In 16.4 per cent. the maximum narrowing was above the duct, in 33.8 per cent. on a level with the duct, and in 44.8 per cent. below it.» The narrowing issometimes double. In about a third of the cases the aorta was sclerotic, and generally more so on the proximal side of the narrowing. The most important secondary changes are hypertrophy of the left ventricle and the formation of collateral cir- culation, the blood reaching the lower portion of the body through the intercostals and the abdominal aorta, through the superficial epigastric and long thoracic arteries and the deep epigastric, and through the anasto- moses of the intercostals with the ilio-lumbar and cir- cumflex iliac arteries. The ductus arteriosus isasarule completely obliterated within from one to two weeks post partum. The oblitera- tion is accomplished by contraction and endarterial prolif- eration. The resulting scar in the wall of the aorta often becomes calcified. Incomplete involution of the ductus arteriosus may become the occasion for thrombosis; the thrombus may project into the aorta and into the pul- monary artery and give rise to embolism (Klob). Transposition of the large veins occurs in connection with cardiac abnormities. There may be two ascending or two descending ven cave, in the first case due to failure of union of the canals of Cuvier; less than or more than four pulmonary veins, which may be inserted into the superior vena cava, into the left innominate vein, or into the ventricles. Either of the vense cave may be absent. An apparent reduplication of the inferior vena cava results from the union of the hepatic veins in one stem, which may empty into the vena cava above or be- low the diaphragm, or directly into the right auricle. The union of the iliac veins may take place higher than usual, the right and the left iliac vein continuing upward on each side of the aorta, sometimes as far up as the liver. Coronary Arteries.—Abnormities of the coronary ar- teries have been described by Hepburn, Turner, Brooks, and others. The most frequent deviation from the normal is an increase in number and irregularities in branching. Brooks describes the origin of a coronary artery in the right anterior sinus of Valsalva of the pulmonary artery ; this abnormal coronary anastomosed with the right coronary and acted as a vein owing to the greater press- ure in the aorta. In another, more complicated case, Brooks found an artery originating in the beginning of the pulmonary artery, anastomosing with the aortic coronaries and the left subclavian artery; it entered into intimate relations with a cirsoid mass at the base of the pulmonary artery. This vessel also acted as a vein, emptying its blood into the pulmonary artery. Aplasia or hypoplasia of an organ or part of the body is associated with absent or diminished development of the corresponding blood-vessels. Abnormal origin and course of arteries and veins are of greater surgical than clinical interest, because it is exceedingly rare to observe that such abnormities cause symptoms. The origin of the right subclavian artery to the left of the left sub- clavian artery and its coursing in front of or behind the cesophagus as it passes over to the right side may cause difficulties in swallowing, according to Eppinger. Dif- ferences in the size of the radial arteries and in the rela- tive depths of their situation frequently give rise to ap- parent differences in the pulse on the strength of which the existence of aortic aneurism may be erroneously diag- nosticated. Vascular Hypoplasia.—Congenital smallness of the en- tire cardio-vascular system is an interesting condition. Morgagni, Meckel, Rokitansky, and Virchow have drawn attention to this arrest of development, especially in chlo- rosis. The walls of the aorta are thin, the intima is the seat of wavy lines, and the lumen scarcely admits the little finger at a period when the aorta usually is twice or more as wide. The condition is frequently associated with arrested development of the reproductive organs and of the sexual characteristics of the body. Apparently the anomaly is probably more frequent in the female than in the male sex. It has been thought that a hypo- plasia of the entire mesoblast is present, including the blood-forming organs; hence the peculiar anemia which is thus explained according to Virchow’s theory. The explanation isno longer regarded as satisfactory. “That a disorder so common and for the most part so curable should depend upon a malformation so grave and so in- curable as this aortic and general vascular hypoplasia is on the face of it highly improbable ” (Clifford Allbutt). The developmental defects in the vessels in heemophilia are considered under the latter heading. RETROGRESSIVE CHANGES IN BLoop-VESsELSs.—Retro- gressive changes of blood-vessels pure and simple are not of so much importance as when associated with other processes in the condition known as angiosclerosis. Atrophy.—In chronic anemia and marasmus simple atrophy takes place in the walls of the blood-vessels, especially in the muscular coat. Atrophy of individual organs is followed by or associated with atrophy of the corresponding vessels. When an extremity is removed the arteries and the veins that nourished the part decrease in size by an atrophy that may be called adaptive; the EB 2 z 2 = FIG. 626.—Atrophy of Left Iliac Artery After Thigh Amputation. (Two-fifths natural size.) vessels become less and less until they carry no more blood than necessary for the nutrition of the remaining tissues (Fig. 626). In the beginning this adaptation is favored by contraction of the arteries and a little later by the development of new connective tissue in the in- tima, so that the lumen of the arteries is reduced in size. 95 Blood-Vessels, Bleod-Vessels,. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Fatty Changes.—Changes in the composition of the blood or disturbances of circulation may induce fatty changes in the walls of otherwise healthy blood-vessels, especially in the epithelial cells and the muscle cells of the arteries. Fatty changes are of common occurrence in arteriosclerosis. A vessel the seat of fatty change presents upon its surface opaque white or yellowish- white patches and irregular lines, running longitudinally or forming a network, sometimes striated, sometimes of a uniform color. The surface is no longer smooth but velvety. These appearances are due to fatty granules and drops of fat inand between the epithelial cells. The change occurs also in the endothelial cells of capillaries. Cells may accumulate around and in areas of fatty change, taking up the oily detritus, and proliferation of cells also occurs. Disintegration of the degenerated areas results in small defects (“fatty ulcers”) which may become the starting point of thrombosis or traumatic and dissecting aneurisms ; on supervention of trauma or severe strain the deeper layers of the intima are ruptured and the blood current makes its way between the layers of the arterial wall. According to Paget fatty degeneration of the media is responsible for many instances of cerebral apoplexy. Fatty changes in the media are Common in various in- toxications. Fatty changes are frequently followed by calcareous infiltration, the arterial wall becoming rigid and inelastic. Fatty changes occur most commonly in the aorta and the pulmonary artery, and then in the arterioles and capillaries, especially of the brain. In veins fatty changes in the intima form white spots, but the veins are notas frequently affected as the arteries. Amyloid Degeneration.—The vascular system is espe- cially prone to amyloid change, which takes its beginning in the media of the arterioles of parenchymatous organs. It also develops in the intima of the larger arteries in extensive widespread amyloid change, appearing as fine striz and points, which are difficult to recognize with the naked eye unless first subjected to the action of Lugol’s solution (see Amyloid Degeneration). Hyaline Degeneration.—Hyaline degeneration of the smallest arteries and veinsand of capillaries is frequently observed in the spleen, the lymph glands, the renal glomeruli, and elsewhere. The epithelium, at first intact, is finally destroyed and the lumen narrowed and occluded. In the larger vessels hyaline degeneration appears first in the intima, and it formsan early step in the complicated degeneration of arteriosclerosis. Hyaline material tends ‘to become calcified. A good example of a hyaline degen- eration of the muscular coat is seen in the pial arteries in tuberculous leptomeningitis. Calcareous Infiltration.—Calcareous particles in glisten- ing granules and as compact masses are frequently de- posited in hyaline and fatty areas; it probably does not occur as an isolated primary process, and is most fre- quent and most extensive in senile arteriosclerosis. Gazert found that in a normal aorta the amount of earthy material is .45 per cent.; in a sclerotic and calcified aorta the calcareous material equalled 8.79 per cent. of the dry residue. Metastatic calcification as a result of resorption in bone is said to involve especially the abdominal vessels, large calcareous plates forming which are separable from the surrounding tissues, In some instances trwe bone has formed in the walls of arteries the seat of petrification. Ossification means pre- liminary vascularization, absorption of pre-existing cal- careous material, and the formation of genuine bone. Von Schrotter and Falk describe with illustrations extensive ossification of arteries in senile gangrene; Cohn found true bone in the aortic valves and in the media of periph- eral vessels. Desquamation of the Epithelium.—In microscopic sec- tions the epithelium of the vessels, both arteries and veins, is found occasionally to have separated from the intima, the peculiar epithelial cells lying curied up in the lumen. This condition is not constant, and the peculiar 96 circumstances under which it occurs have not been estab- lished. The loosened epithelial cells have been mistaken for sarcomatous emboli. HYPERTROPHY AND HyPERPLASIA.—Hypertrophy and hyperplasia of arteries are observed in connection with various forms of tissue overgrowth, ¢.g., the uterus in pregnancy, large tumors, and the adaptive hypertrophy of one kidney in case of extensive disease or absence of the fellow kidney. Obstruction to the blood current and increased arterial tension, as in cases of hypertrophy of the heart and of chronic nephritis, produce more or less hypertrophy of the muscular coat of the arteries. The power of the arteries and veins to adapt themselves to . new conditions is best shown by the changes that take place in the development of collateral circulation. In- deed, this is one of the richest fields for the study of pathological adaptation. Vessels and vascular systems adjust themselves with wonderful precision to changes in pressure, in velocity, and in quantity of circulating blood. Readjustment is accomplished by virtue of the vaso-motor nervous mechanism and the physical proper- ties of the arterial walls, aided under special conditions by structural changes. The physiological prototype of collateral circulation is seen in the changes that occur in the fetal circulation after birth. The ease with which the important rearrangements to the conditions of extra- uterine life are accomplished indicates that the mechan- isms for adaptive changes on the part of the circulatory system are good; as in almost all pathological adapta- tions, the mechanisms are in better working order in the young than in the adult and the old. The extent of the changes incidental to the develop- ment of collateral circulation will depend naturally upon the location of the obstruction and upon the size and the number of the collateral branches. Formerly it was taught that the increased pressure above the obstruction was the cause of the development of collateral circula- tion; increased pressure is now regarded as a factor of little consequence. Nothnagel has shown that there is really no rise of pressure in the vessels above the obstruc- tion or ligature unless they stand in communication with branches below the obstruction. As advanced by von Recklinghausen, the increase in the extent of the capil- lary bed of the collateral branches, through which the blood flows into the capillaries of the obstructed vessel, results in increased rapidity of the current; and Thoma has demonstrated that increased rapidity of the current is followed by a widening of the lumen of the vessels, in- creased thickness of the wall, and growth in length. In this way the need of the tissues for blood is satisfied. The structural changes that take place in the walls of the collaterals may be regarded as the expression of a work- hypertrophy. And conversely, the gradual thickening of the intima of the occluded vessel as far back as the nearest collaterals is to be regarded as the result of diminished need of work. In obstruction to the portal circulation by cirrhosis of the liver the dilatation and hypertrophy of the veins through which collateral circulation is gradually estab- lished may become marked. In exceptional cases the cesophageal veins become enlarged to many times their normal size and afford so complete escape for the portal blood that the congestions and the ascites of cirrhosis fail to appear and the clinical picture of the disease is masked. . INFLAMMATION (ANGEDTIS, VASCULITIS).—Inflamma- tion may affect principally the adventitia, the media, or the intima (periarteritis and periphlebitis, mesarteritis and mesophlebitis, endarteritis and endophlebitis). On account of the structure of the venous wall, these dis- tinctions are not as marked in veins as in arteries. An- geiitis may assume various types, such as productive, suppurative, tuberculous, and syphilitic. Angeiitis may result from the extension of inflammatory processes in the neighborhood (consecutive angeiitis); it may be caused by wounds of arteries or veins and by other forms of trauma, such as tearing and crushing (traumatic arteritis and phlebitis); it develops as a result of infec- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood-Vessels, Blood-Vessels, tions (pyogenic, syphilitic, and tuberculous) and of in- toxications; in angeiosclerosis arteritis and phlebitis are observed as consecutive processes, secondary to nutritive and mechanical disturbances in the vessel wall. Arteritis and phlebitis sustain a double relation to throm- bosis inasmuch as thrombosis in an artery or a vein in- duces inflammation (thrombo-arteritis, thrombo-phlebitis) while angeiitis not uncommonly leads to thrombosis. The causes of infectious or toxic angeiitis may reach the part of the vascular wall first involved through either the vasa vasorum, the lymph stream, or the main blood stream within the lumen of the vessel, or they may come directly from without. It was the custom of pathologists in the early part of this century to look upon imbibition and reddening of the tunica intima as evidences of acute inflammation; in 1847 Virchow proved the incorrectness of this view. Because the same agent may produce more than one form of arteritis and phlebitis, and because the same form of angelitis may result from more than one cause, it be- comes rather difficult to make at once a comprehensive yet simpie classification of arteritis and phlebitis. When we omit from consideration periarteritis nodosa and the specifically tuberculous and syphilitic varieties, then the remaining forms belong to one of two large groups, the suppurative and destructive or the productive, the first characterized by disintegration and the formation of pus, the second by the production of new tissue. Suppurative Angetitis ; Suppurative Thrombo-Arteritis. —The form of disease of the arterial wall induced by thrombosis or by the lodgment of emboli is determined by the nature of the thrombus or embolus. In the case that pyogenic bacteria are present in their interior, puru- lent inflammation is set up in the walls of the artery, re- sulting in a more or less extensive and destructive pan- arteritis and periarteritis, the final outcome being an abscess. This is what occurs in the development of metastatic embolic abscesses in the lungs. At other times the destructive action of the bacteria in infected emboli may be more limited in its extent, thereby pro- ducing a local weakening of the arterial wall, at which point aneurismal bulging occurs and there results a so-called embolic or mycotic aneurism (Goodhart, Ep- pinger). Mycotic embolism, the result of embolic sup- purative arteritis, is observed most frequently in the cerebral arteries. Purulent thrombo-arteritis, with or without mycotic aneurism, is liable to result in hemor- rhage from the weakening and destruction of the vessel wall. Suppurative Thrombo-Philebitis.—This may result from the extension of a suppurative process about a vein to the adventitia, media, and intima, which is more fre- quently the case than thrombosis upon the basis of a primary mycotic endophlebitis. In either case the re- sulting thrombosis undergoes purulent or purulent and putrid softening under the influence of the microbes that gain entrance into it from the walls of the vein. Begin- ning with John Hunter, in 1798, who described inflam- mation of the inner walls of veins after blood-letting and in the uterine and femoral veins of women in the puer- peral period, it gradually became established clearly that pyemia commonly depends upon suppurative thrombo- phlebitis, the circulating blood being the medium of ' transference of infected particles from the thrombus to various parts of the body, the emboli on lodgment pro- ducing metastatic abscesses. Among veins that are liable to suppurative thrombo-phlebitis may be mentioned the umbilical veins in the new-born, infection taking place at the navel; the lateral and other sinuses of the dura mater in suppurative mastoiditis and middle-ear disease; the mesenteric veins in appendicitis and ulcerative processes in the intestines, the process giving rise by extension or embolism to suppurative pylephlebitis and abscesses of the liver; the subcutaneous veins in the vicinity of the foci of infection, etc. Suppuration originating in a diver- ticulum of the cesophagus has extended to the superior vena cava and given rise to suppurative thrombo-phlebitis in this vein. Vou, II.—7 Mycotic and Toxie Endangetitis.—Acute verrucose and ulcerative endangeiitis, similar to acute endocarditis, most frequently occurs in the aorta and the pulmonary artery and is usually associated with infective endocarditis of the semilunar valves. It has also been described in the larger and medium-sized branches of the aorta and the pulmonary artery. The lesions usually assume the form of warty eminences, composed of a cellular and vascular granulation tissue and capped by thrombotic deposits, There is more or less cellular infiltration into the tissues of the vessel wall near such warty outgrowths, and at times the process assumes more of an ulcerative and de- structive type. Osler has described an interesting in- stance of multiple mycotic aneurisms of the aorta the re- sult of infective endaortitis associated with acute infective endocarditis. Schmey has recorded the sudden develop- ment of aneurisms, one upon the radial artery and one upon the posterior tibial, in a boy of twelve with acute articular rheumatism, showing that in all probability the microbe or toxin of this disease may also cause this rare form of endarteritis. Such aneurisms, although not embolic, belong etiologically in the same general cate- gory as the embolic-mycotic aneurisms just referred to as caused by embolic destructive arteritis. Oliver de- monstrated B. anthracis in an ulcerative aortitis. It is now recognized that the acute and chronic forms of arteritis occur in various infectious diseases—ty phoid fever, smallpox, scarlet fever, measles, acute articular rheumatism, influenza, pneumonia, syphilis, tuberculosis, and leprosy. In the acute forms cellular infiltrations, gen- erally circumscribed, are found in the outer coats of the vessels together with more or less extensive proliferation of the subepithelial connective tissue of the intima. Nodular and more diffuse accumulations of lymphoid and epithelioid cells occur beneath the epithelium. These changes are explained as due to the circulation in the blood of the microbes and the toxins of the diseases men- tioned. When the endarterial changes result in destruc- tion of the living epithelium thrombosis takes place, and if it is in a larger vessel a typical verrucose endarteritis may be established. The endarteritic lesions are due to a direct implantation of micro-organisms upon the intima in the same way as infections of the endocardium take place; inasmuch as bacteria are often absent, it seems that endarteritis may be caused by toxins also. These changes occur probably more frequently in the veins than in the arteries. Arterial thrombosis in the diseases mentioned is often referable to infectious arteritis. It is quite evident that there might be more or less difficulty in distinguishing between toxic and infectious verrucose endarteritis and thrombo-arteritis pure and simple. The formation of a parietal thrombus upon a rough spot or thickening of the intima might induce small nodular outgrowths of new tissue. The presence of microbes in the thrombus would indicate that the acute and destructive changes in the walls of the vessels were primary. In many instances of multiple venous thrombosis it is not unlikely that an infectious or toxic endophlebitis is the primary change in the vessel wall. In typhoid fever, diphtheria, variola, influenza, and other infectious dis- eases there is found a nodular, sometimes a more diffuse, accumulation of lymphoid and epithelioid cells in the intima, even more frequently than in the arteries. Many of the large cells in such foci seem to have marked phagocytic properties (Mallory). The accumulated cells, as well as the epithelium, may undergo necrosis and become the starting-point of a thrombus. JInas- much as bacteria are often absent, it would seem that the vascular lesion may be caused by toxins—a toxic endangeitis. Lancereaux and others believe that there is a malarial aortitis which “occurs in the form of gelatinous plaques, situated generally in the ascending part of the arch of the aorta; the lesion is described as beginning in the ad- ventitia with cellular infiltrations which result in atrophy of the media and an adaptative thickening of the intima. Saccular aneurisms may result. It seems that there OT Blood-Vessels, Blood-Vessels, would be great difficulty in distinguishing between ma- ’ Jarial aortitis and nodular sclerosis from other causes. Experimentally aortitis has been produced by the in- jection of various microbes—B. typhosus, B. diphtherie, streptococcus, etc.—sometimes with and sometimes with- out previous traumatism to the artery by means of a probe inserted through the carotid. The French espe- cially have been interested in this work (Gilbert and Lion, Therése, Crocq, Pernice, Boinet and Romary). In some cases the lesions were vegetative, in others gelatinous plaques due to endarterial proliferation resulted. In- filtrations about the vasa vasis were often present. Nod- ular thickenings are described by Boinet and Romary as following the injection of toxins, of lead, urate of soda, and phloridzin, with or without preceding injury. In their later stages the lesions would be identical with nod- ular arteriosclerosis. Metastatic abscesses in the walls of arteries are rare. Virchow observed one in the beginning of the pulmonary artery; and Eppinger describes an abscess, the size of a walnut, in the posterior wall of the aorta just distal to the origin of the left subclavian artery. Andral de- scribes a case of multiple abscesses, of the size of hazel- nuts, in the wall of the aorta, but there is some doubt as to the real nature of this case. Spengler describes an abscess in the wall of the aorta just above the semilunar valves. Consecutive Huudative and Suppurative Angetitis.— While blood-vessels possess considerable resistance against the invasion of suppuration from without, so that in large abscesses it is not unusual to find the vessels wholly freed from the surrounding tissue and bathed in pus, yet periarterial and periphlebitic infiltration and proliferation are common consecutive lesions. This oc- curs in the vessels at the base of the heart in acute exuda- tive pericarditis, pleuritis, and mediastinitis; the adven- titia is then the seat of an cedematous, sero-purulent, and purulent infiltration. And suppurative and necrotic proc- esses around blood-vessels may extend not to the adven- titia only, but also to the media and the intima, causing necrosis of the epithelial lining and secondary thrombo- sis. In this way also may develop suppurative thrombo- arteritis and thrombo-phlebitis. The weakening of the wall of arteries caused by the purulent disintegration of the media sometimes results in another form of aneuris- mal dilatation—erosion aneurism produced by a kind of hernia of the inner coats at the point of least resistance. This result of consecutive peri- and mesarteritis is espe- cially frequent in the branches of the pulmonary artery that are exposed upon the floor and the trabecule of phthisical cavities. The aneurismal bulging takes place upon the side of the artery that is least supported by surrounding tissue, namely, that toward the lumen of the cavity. Frequently an obliterating thrombosis pre- vents the formation of aneurism and removes the dan- ger of hemorrhage under these conditions. Suppuration in a wound, or in an amputation stump, may destroy the granulation tissue formed by the intima in the process of definitive closure of an artery, cause purulent disintegra- tion of any thrombus present, and thus give rise to the much-dreaded secondary hemorrhage of the preaseptic times. Colin and Flexner describe instances of perforation of the inferior vena cava in amoebic abscess of the liver. On subsidence of acute inflammatory lesions of this nature, vascular granulation appears in the walls of the vessel, producing more or less extensive fibrous thicken- ing of the various coats with narrowing of the lumen; in case thrombosis has taken place, the substitution of the thrombus by connective tissue may cause occlusion of the vessel. Terminal fibrous changes of this kind do not differ histologically from the lesions of many primarily productive forms of angeiitis. Productive Angetitis.—Inflammation of blood-vessels resulting in the production of new tissue is a frequent form. In productive or obliterating endarteritis and en- dophlebitis there occurs a proliferation of the cellular elements of the intima, which leads to thickening of the 98 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. intima, eccentric narrowing of the lumen, and eventually to complete occlusion. This process is observed under a variety of conditions. The occlusion after birth of the ductus arteriosus and the umbilical vein and arteries is accomplished by the formation of connective tissue by the intima; as the pressure of the blood in these vessels fails, a degree of contraction ensues that favors the filling of the vasa vasorum; in the narrowed lumen a small thread-like thrombus may form which is finally substitut- ed by fibrous tissue. Similar changes occur in occlusion following ligature, and in the narrowing of the lumen of vessels the capillary bed of which has been restricted (amputations, indurative processes in the lungs, etc.). In these conditions there is usually atrophy of the media. A ligated vessel may be occluded by intimal proliferation without thrombosis taking place; in many cases a throm- bus forms, which is then replaced by granulation tissue. In the old and feeble, especially when the arteries are sclerotic, the intima may have lost its power of prolifer- ating and then there is danger of secondary hemorrhage. Productive Thrombo-Arteritis.—The presence in an ar- tery of a thrombus, whatever the cause of the thrombo- sis may have been, or of an embolus, is sooner or later followed by reactive changes on the part of the vessel wall, which result in the production of a vascular gran- ulation tissue, provided destructive infection does not. occur. The plug becomes infiltrated with leucocytic phagocytes and with fibroblasts. The amount of new tissue and the rapidity with which it is formed will de- pend more or less upon the age of the patient and upon the previous condition of the walls of the artery in ques- tion. The vessels of the aged, the walls of aneurisms and of sclerotic arteries are often so changed and degen- erated that but slight or no reactive proliferation takes. place under conditions that in young healthy arteries are followed by vigorous growth of new tissue. The ves- sels present in the new tissue result in part from in- growth of vascular sprouts from the vasa vasorum, in part from the epithelial cells of the intima. In case the lumen of the artery is but partially occluded, then the tissue replacing the thrombus or embolus gives rise to various forms of intimal thickening—flattened elevations, projecting ridges and bands, cord-like networks. Com- plete occlusion of the artery may be followed by cica- tricial obliteration of the lumen, or the new tissue may be so traversed by vascular spaces that the continuity of the lumen in some measure is restored. (For further de- tails concerning connective-tissue substitution of throm- bi, see article on Z’hrombosis. ) In the healing of wounds of arteries and veins a thrombus composed of blood plates and of fibrin first forms, which is subsequently replaced by new fibrous tissue. Productive Thrombo-Phlebitis.—Productive inflamma- tory changes occur in the walls of veins after thrombo- sis. The process pursues the same general course as thrombo-arteritis. It is observed especially in the peri- uterine veins, the veins of the lower extremities, the pel- vic veins, and the sinuses of the dura, which constitute those parts of the venous system that are most frequently the seat of thrombosis. The residues of connective-tissue replacement of a venous thrombus may be fibrous bands coursing across the lumen, the interior of the vein resem- bling that of a dural sinus, more diffuse intimal thicken- - ings, and great shrinking of the part of the vein involved with complete obliteration of the lumen. Such changes may occur also in the larger veins, such as the vene cavee.. I refer with more detail to occlusion of the superior vena cava in the section devoted to tumors of the vessels. Obliterating Endophlebitis of the Hepatic Veins.—An obliterating, proliferative phlebitis occurs in the main stems of the hepatic veins. This process has recently been studied by Chiari. In seven cases collected by Chiari there were periphlebitic proliferative processes or thrombosis followed by productive thrombo-phlebitis. Chiari describes three instances of an apparently primary obliterating phlebitis of the main stems of this vein, which on account of the resulting circulatory disturb- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ances became the cause of death. The endophlebitic process was situated in the proximal portions of the veins with peripheral extension in one case. The ten- dency to obliteration was marked, leading to mechani- cal obstruction and fateful secondary thrombosis. The Fig. 627.—Obliterating Endarteritis in Chronic Salpingitis. Hsema- toxylin and eosin. X 100. condition is undoubtedly a peculiar one, possibly of syphilitic origin; in one case it was associated with simi- lar changes in the coronary arteries. Consecutive Productive Angetitis.—Inflammation, acute and chronic, generally takes place in the walls of all arteries that lie in tissue the seat of inflammatory proc- esses. In this case cellular infiltration and proliferation extend into the vessel wall from without inward, and all the coats may in time become fibrous; the thickening of the intima caused by the proliferation of fibroblasts and the formation of new fibrous tissue is generally pro- nounced and complete obliteration of the lumen may take place. In many instances the formation of fibrous tissue in the intima of vessels in organs the seat of chronic fibrous processes is undoubtedly in some measure the result also of obliteration of portions of the capillary districts of the vessels (Thoma), the resulting narrowing of the lumen partaking of an adaptative nature—a local- ized form of secondary angeio-sclerosis. Changes of this general character are seen in chronic interstitial inflam- mations and fibrotic processes in the parenchymatous or- gans, as in interstitial nephritis, orchitis, etc. (Fig. 627). They are well marked in the specific granulomatous proc- esses, and the resulting arterial lesions need not always necessarily present any specific characteristics. The acute stages can be studied nicely in the pial arteries in tuberculous leptomeningitis. There is leucocytic infil- tration of the adventitia, extending into the media and intima; the wandering cells are seen making their way between the fibres of the media and through the fenestra- tions of the internal elastic coat, the nuclei being drawn out long so as to pass through narrow spaces; the elastic coat at times becomes broken through by the cells which may accumulate under the epithelium; simultaneously fibroblasts appear, especially in the subepithelial layers of the intima (see Tuberculous Arteritis) (Fig. 628). Simi- lar changes of a more chronic but non-specific character are seen also in the walls of arteries and veins in chronic tuberculous areas and cavities in the lungs. Great nar- rowing of the lumen and even closure may result from the newly formed fibrous tissue in the intima. Quite simi- lar changes occur in syphilitic lesions, and it is probable that an isolated, primary, histologically non-specific, productive endarteritis is often caused by syphilis. In productive endarteritis of whatever cause, fibrillar con- nective tissue interspersed with elastic elements is formed inthe intima. Attimesa distinct, new, elastic membrane develops; it is generally thinner than the original elastic Blood-Vessels, Blood-Vessels, layer, the general course of which it imitates, and it forms the inner boundary of the new, greatly narrowed lumen. But the process is not thereby brought to a standstill, as new fibrous tissue may again form and completely occlude the vessel. The fibrous perivascular changes that develop in con- nection with productive angeiitis of diffuse character lead to obliteration of the perivascular lymph spaces and se- rious obstruction of the lymph flow, which in some tis- sues, as for instance the brain, may produce grave dis- sete of the function and the structure of the special cells. Acute endarteritis may in time give rise to fibrous nod- ules upon the intima and to more diffuse thickening. Fenger describes an extensive polypoid fibrous endarteri- tis of the pulmonary artery associated with valvular en- docarditis. The polypoid outgrowths, which almost close the lumen, sprang from the deeper layers of the intima. Willigk described numerous, small pedunculated vege- tations. Eriksen noted large radiating scars, producing annular stricture, in the stem of the pulmonary artery, and Willigk found a stenosis of the right pulmonary ar- tery, the lumen being reduced to a diameter of 2 mm. Goebel describes a local endarteritis that gives rise to small elevations in the intima. The process involves only the intima. The resulting thickenings are based upon the elastic coat and are composed of a network of fibrille and elastic elements apparently splintered off from the elastic layer; the nodules are partly vascular. As they become polypoid, thrombosis may result and cause gangrene, which was the case in an instance of spontaneous gangrene in a child, one and a half years old, that forms the basis for his study. Goebel found similar nodules in medium-sized arteries in three of . twenty children examined for this process. The cause is obscure; possibly some form of traumatism may be the underlying condition. Syphilis was excluded. It may be added by way of suggestion that a local toxic or infectious endarteritic process might result in such ele- vations. Elastic Fibres in Endarterial Proliferations. — The newer methods of staining elastic fibres, elaborated by Tinzer and Unna and by Weigert, have resulted in the demonstration that they are pres- ent to a greater extent in the end- arteritic prolifer- ations than was formerly thought. Langhans be- lieved that the pre-existing elas- tic layer—the elastica interna— underwent hy per- trophy. Heubner found that in ar- teriosclerosis the inner layer of the elastica becomes granular, and that in the later stages of the disease four to eight or more elastic bands appeared in the thickening of the intima; in syph- ilis a new elastic membrane formed near the lumen in the quiescent stages; Heubner derived the new elastic elements from the epithelial cells. Wendeler pointed out that in syphilis each period of growth in the intima closes by the forma- tion of an elastic membrane. Dmetrieff shows that in ar- teriosclerosis the newly formed elastic fibres in the intima ‘t Hh Fig. 628.—Chronic Endarteritis in Chronic Tu- berculous Meningitis. a, Blood spaces. X 150 diameters. 99 Blood-Vessels, Blood-Vessels, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. have the same general course as the fibres of the media (see Fig. 629). Jores holds that elastic fibres are formed in two ways: the one is due to the splitting up of the internal elastic layer into several lamella, some of which may appear as quite independent bands. This process occurs especially in arteriosclerosis and probably to some extent under normal conditions. But the new formation of fine fibres is by far the most important. Jores favors the theory that these fibres are formed by the secretory activity of the young connective-tissue cells, although it cannot be said that the origin of elastic elements from chemical changes in the collogenous intercellular sub- stances has been wholly disproved. In intimal prolifer- ations Weigert’s elastic-fibre stain shows that the new fibres appear first as finer granular lines that surround the cells as a fine network. ‘The epithelial cells do not seem to play any part in this process, inasmuch as elastic fibres never appear between the -individual epithelial cells, but are always confined to the subepithelial layers. From observations on ligated vessels Jores found that new elastic fibres are formed more numerously in vessels subjected to the pressure of the circulating blood than in parts enclosed between two ligatures or in vessels the seat of thrombo-arteritis. Hence he regards the new formation of elastic fibres as distinctly compensatory in character. ‘The cells in intimal proliferations are gifted with greater powers to form elastic fibres, directly or in- directly, than the cells of the media. Malkoff and Gardner hold that the elastic fibres devel- op in the outer layers of the cell bodies. In typical endarteritis obliterans there is not much change in the elastic elements, which maintain the same relation in endarteritis obliterans as in productive throm- bo-arteritis. In arteriosclerosis, on the other hand, the intimal thickening occurs in layers separated by elastic fibres (Falta). Obliterating Endarteritis and Spontaneous Gangrene. —The occurrence of obliterating endarteritis in an inde- pendent, primary form has not been established upon a satisfactory basis. Its occurrence as a secondary process in indurative processes, in the organization of thrombi, and as the result of consecutive and specific arteritis is generally recognized since Friedliinder, in 1876, first called especial attention to endarteritis obliterans. Heubner interpreted endarteritis of the cerebral vessels as always a specific syphilitic lesion, but Baumgarten showed that not endarteritis obliterans is the specific form of syphilitic vascular disease, but gummous arteri- tis, in which the changes in the adventitia are equally if not more prominent than those in the intima. The endarteritis obliterans observed as the case of spontaneous gangrene in the middle-aged and the young is regarded by von Winiwarter, von Schroétter, Borchhardt, and others as a distinct and primary disease. This opinion is based largely upon the fact that premonitory symp toms, indicative of gradual occlusion of the arteries, may exist a long time before culminating in gangrene, the more prominent symptoms being pain, cyanosis, and coldness. Insome cases the complex of symptoms called by Charcot “intermittent claudication ” has been present. The arteries more frequently involved are those of the foot, leg, and forearm. The endarteritis, which is de- scribed as typical, with vascularization of the new tissue in the intima and reduplication of the elastic coat, begins in the peripheral branches. The adventitia may be greatly thickened, and in some cases the neighboring veins and nerves were found extensively involved in the perivascular sclerosis. In many cases thrombosis or pigmentation, the probable result of thrombosis, was present, and Thoma, who does not believe there is a special form of obliterating endarteritis, holds that the endarteritic changes in this form of gangrene result from the replacement by connective tissue of thrombi in scle- rotic vessels. Zoege von Manteuffel claims that the gradual occlusion is brought about by the deposition and organization of successive layers of parietal thrombi in primarily sclerotic arteries. Von Recklinghausen de- scribes hyaline thrombi in the smaller arteries of limbs the 100 seat of spontaneous gangrene. Haga regards endarteritis thrombotica as syphilitic. Hoegersted and Nemsen find that parietal thrombi in sclerotic arteries may result in occlusion and constriction of the vessels. Falta has de- scribed cases of gangrene in old people as due primarily to arteriosclerosis associated with an apparently inde- pendent productive process in theintima. Goebel attrib- uted spontaneous gangrene in a child, one and a half years old, to thrombosis at the bifurcation of the popli- teal artery produced on account of the presence of small globular elevations composed largely of elastic elements and caused by a local endarteritis of obscure origin. The conditions that may produce spontaneous gangrene not caused either by embolism and secondary thrombo- sis or by arteriosclerosis and thrombosis are consequently rather complicated. Undoubtedly many instances result from arterial thrombosis secondary to the endarterial in- flammatory changes that occur in various infectious dis- eases (see Gangrene). ANGIOSCLEROSIS. —Definition.—It is quite impossible to give a comprehensive definition of angiosclerosis, be- cause as at present used this term, and the more common term arteriosclerosis, undoubtedly include processes of different nature. Angiosclerosis is, to say the least, a complex process that appears under different conditions in varying stages and varying distribution. The general idea conveyed by the term is fibrous thickening and oth- er changes in the intima consequent upon changes of a degenerative nature in the media of arteries and veins. When the process affects arteries, and that is by far its more prominent, more important, and more frequent lo- calization, itis known as arteriosclerosis; and sclerotic changes in veins constitute phlebosclerosis. In cases of diffuse sclerotic changes in the vessels both arteries and veins are often involved, but the arterial changes are the more conspicuous both from the clinical and from the anatomical points of view. The term arteriosclerosis was introduced by Lobstein over fifty years ago; he regarded the process as the re- sult of nutritive disorders in the vessel wall incident to age and use. The word atheroma is used by some as almost synonymous with arteriosclerosis, but in reality atheroma is applicable only to certain late stages of the process, as it affects the aorta and its large branches. In the text-books of pathological anatomy of fifteen to twenty years ago arteriosclerosis is described generally under the heading endarteritis chronica deformans s. nodosa, and phlebosclerosis is mentioned sometimes as endophlebitis chronica deformans s. nodosa; these terms were introduced by Virchow; they are now rarely used. Other quite synonymous names are arteriocapillary fibrosis, introduced by Gull and Sutton, and arteriofibro- sis. Since Thoma’s epochal investigations, the terms arteriosclerosis, phlebosclerosis, and angiosclerosis are used quite universally. Atheroma should not be used as synonymous with arteriosclerosis. Pathogenesis and IHistogenesis.—Through the investiga- tions and theories of Thoma and his students, angioscle- rosis, in some of the phases of its genesis, has been placed upon the same basis as certain processes that oc- cur in the vessels, especially the arteries, under normal physiological conditions. The physiological paradigm of angiosclerosis is seen in the changes that take place in the aorta immediately after birth. At birth there is no connective tissue in the intima of the aorta. Immediately after birth the cir- culation in the umbilical arteries ceases; a part of the territory of the aorta is cut away, the aorta is now too large in comparison with the area it supplies with blood, and the circulation in it becomes slower. Under these circumstances connective tissue develops in the intima of that part of the aorta between the ductus arteriosus and the hypogastric arteries, and in this way its lumen is reduced to a size commensurate with the rate of blood current best suited to the needs of the tissues for nour- ishment. Later in life similar changes occur normally in the carotid, for instance, because from the eighth to the tenth year the growth in strength of this artery does REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. not keep pace with that of other vessels; hence it dilates, its lumen becomes so large that slowing of the circula- tion takes place, and new tissue develops in the intima until the current reaches the normal flow (Sack). Simi- lar changes take place in arteries after amputation and in arteries whose capillary area is destroyed by disease. The connective-tissue formation in these cases is there- fore spoken of as compensatory, calculated to reduce the lumens of the arteries to their proper size. From these and other observations the general theory is deduced that every slowing of the blood current in the arteries and veins of man that is not completely and at once remedied by a proportionate contraction of the me- dia, leads to a new growth of connective tissue in the intima, which narrows the lumen of the affected vessel, and thus restores the normal swiftness of the blood cur- rent more or less completely (Peabody). It may be said here that the compensating endarteritis is regarded as the result of mechanical and chemical changes that oc- cur in and about the cells of the intima of the part of the artery affected; it is not claimed that the compensat- ing proliferation is distinctly and purely teleological in its nature. In order to explain the new growth in the intima, Thoma has elaborated a rather complex theory according to which the irritation produced by the abnor- mal conditions upon the vaso-motor nerves connected with Vater-Pacini’s corpuscles in the adventitia, leads to functional disturbances and hyperemia of the vasa vasorum and eventually to new tissue in the intima. But intimal thickening occurs in vessels that have no vasa vasorum when the current is supposed to be slower than normal. The origin of the new tissue in the intima is traced partly to the epithelial cells (Baumgarten, Thoma), partly to the connective-tissue cells in the subepithelial layer. The latter are probably the more important fac- tors in the process. Ingrowth of connective tissue from the media and of vessels from the vasa vasorum is also mentioned as possible by some writers. The weakening of the wall and consecutive local or general dilatation that gives rise to compensatory thick- ening in the intima are regarded as the result of wear and tear, of strain, of heightened intravascular pressure, and of toxic and infectious influences. These factors may operate singly or in combination. The obliteration of capillary areas and the narrowing of smaller, peripheral vessels are also held to induce thickening in the intima of the larger vessels because of the relative abnormal wide- ness of their lumens under these circumstances, but here it is manifestly difficult to determine the primary events in the process. Thoma showed by physical tests upon the iliac arte- ries that weakening and dilatation of the arterial walls may occur in the early stages of arteriosclerosis without evident structural changes in the vascular tunics be- ing present. Other investigators describe structural changes, especially in the elastic elements, that surely give rise to loss of strength and elasticity in the arteries affected. : Weiszmann and Neumann, Zwingmann, and others described tears in the elastic lamelle and granular disin- tegration of the elastic fibres of the aorta in arterioscle- rosis. Manchot observed similar changes in the aorta in the wall of aneurisms. Eberhardt was inclined to at- tribute the changes described as artefacts due to the use of alcohol not wholly free from water in the staining method then employed, in which fuchsin was the prin- cipal ingredient. Eberhardt found, however, that the changes described occurred to a slightly greater extent in the elastic lamelle and fibrous network of the artifi- cially distended than in the non-distended carotid ar- tery. Hilbert found that tears or transverse ruptures of the internal elastic coat occur at all ages in the arteries near the heart (aorta and carotids); in youth they are rare in the external iliacs, but after the fourth decennium they are frequent here also. In the renal and similar arteries ruptures are rare at allages. Internally to the ruptures Blood-Vessels, Blood-Vessels, may be one or more layers of evidently modified or new elastic fibres. In theiliacs he noted amarked separation or splintering of. the internal elastic layer in aortic in- sufficiency. The ruptures that he describes are attrib- uted to momentary increase in the blood pressure under sudden physical exertion or mental excitement. They occur also in hypertrophy of the left ventricle and in cases of probable diminished resistance on account of nutritive disturbances. Sclerosis and aneurisms may result. By means of more improved technical methods, Dmitri- jeff has recently studied the changes in the elastic ele- ments of the arterial wall in arteriosclerosis. He finds that the principal change in the media is a granular dis integration of the elastic fibres, which begins first in the inner parts of the media in the network between the elastic lamelle. The granules appear in chains, and stain, some well, some poorly, with acid orcein. Later, changes appear in the lamelle, which stain irregularly and break up into irregular pieces. The chemical na- ture of the elastic elements changes in some way and they become basophilous; Unna’s modified elastin, elacin, is present. These are the earliest changes in the vessels and occur especially in advancing years; Dmitri- jeff found them also in the aorta of an eight-year-old child that died from scarlet fever. At the same time nodules or more diffuse thickenings appear in the intima, composed of fibrous tissue and new elastic elements ar- ranged either as lamelle or as networks of fine elastic fibres; this new formation easily undergoes degeneration (atheromatous changes), so that in arteriosclerosis there is degeneration of and new formation of elastic fibres. Foci of inflammation and proliferation in the adventitia and the media also lead to destruction of the elastic fibres in their vicinity. Peri-arterial and mesarterial inflamma- tory infiltrations about the vasa vasorum were regarded as of great importance by Késter, Huchard, and others. The etiology of such foci is probably to be sought in toxic and infectious influences. Martinand other French writers go so far as to advocate that the degenerative (atheromatous) changes in the large arteries are the result of sclerosis of the vasa vasorum. Malkoff, from the experimental study of the effects of crushing and stretching of the carotid artery, concludes that injuries of various kinds produce changes in the walls of the arteries that render the wall less resistant and dilatations are produced; but after a time the lumen may be narrowed again by a growth of connective tissue and elastic elements in the intima and also in the media; the lumen may become even narrower than before the injury. The experiments were not extended over a pe- riod of time sufficient to disclose the ultimate results. But in angiosclerosis the compensatory proliferation of new tissue in the intima is sooner or later followed by more pronounced degenerative changes. The new tissue is not able to maintain its integrity in the face of the constant strain of the intravascular pressure and of the inadequate facilities for nutrition. Hyaline and fatty changes take place in the deeper layers of the intimal thickening and in the inner layers of the media. Com- plete disintegration into fatty and granular débris mixed with cholesterin tablets and crystals of fatty acids give rise to smaller and larger foci of softening that have been termed atheromatous abscesses. By extension the overlying tissue may be destroyed, and defects arise in the intima—“atheromatous ulcers”—upon the rough surface of which fibrin may be deposited. Petrification often takes place in the degenerated tissue and calcare- ous plates and irregular masses form in the intima and inner layers of the media. True bony tissue has also been found to develop. It is to this degenerative stage of arteriosclerosis, which is seen best in the aorta and its larger branches, that the term atheroma is frequently applied. In advanced cases the sclerotic, degenerative, and petrifying changes are present in varying degrees and produce great deformity, unevenness, and changes in the normal color of the intima and irregular dilata- tions of the vessels. The relation of arteriosclerosis to 101 Blood-Vessels, Blood-Vessels. aneurism and of phlebosclerosis to varicosity of the veins is elaborated under these respective headings. Etiology.—The etiological relations of angiosclerosis are ill defined. So far it has not been possible to pro- duce experimentally sclerosis of vessels of animals com- parable to the human disease, except possibly the gelati- nous nodules in the aorta that French investigators describe after the introduction of bacteria and of toxic substances with or without preceding injury to the inti- ma; these nodules resemble the lesions of nodular arterio- sclerosis. Angiosclerosis is rarely observed in animals; it has been seen mostly in old cattle and in old horses. According to Edgren’s statistical study of arterioscle- rosis, syphilis, alcoholism, and old age are the predomi- nating factors in its production. Henschen, in his criti- cism of Edgren’s work, points out that the source of the material for such studies must be carefully scrutinized because conclusions based upon the presence of arterio- sclerosis in the inmates of institutions that harbor espe- cially syphilitics, alcoholics, or old people naturally will be one-sided and misleading. Such studies usually take no note of the form of arteriosclerosis present. Angiosclerosis occurs so commonly in advanced years that itis generally regarded as a sort of involutional change; this is true especially of the senile form of arte- riosclerosis. It is thought that the media gradually loses its elasticity; dilatation and the formation of more or less new tissue in the intima followed by degenera- tion take place. According to Thoma a moderate de- gree of thickening of the intimais frequent after the thirty-sixth year, especially in the peripheral arteries. The period of life at which a well-marked arterioscle- rosis appears and the extent that it may assume are de- pendent upon the natural, inborn resisting power of the muscular and elastic elements of the arterial wall and upon the amount of wear and tear to which the vessels are subjected. The tendency seen in certain families to the early development of arteriosclerosis is explained as due, at least in part, to an inherited weakness of the arterial walls. This theoretical conclusion has received as yet no confirmation in the form of demonstrable ana- tomical deviations from the normal in the structure of the arteries of such individuals. On the other hand, there are cases recorded in the literature of centenarians with smooth and normal vessels. Changes similar to arteriosclerosis have been described in the vessels of children and young persons. Von Schrot- ter enumerates several recorded instances; Young de- scribed sclerosis of the temporal artery in a child of fif- teen months; Meigs of the left coronary artery in a child of five months; Gee described aneurisms of the coro- nary arteries and atheromatous changes in the aorta in a child of seven years that died from dropsy and pneumo- nia following scarlet fever; and Chiari observed sclerosis of the aorta with typical histological changes in a boy of thirteen years, the disease being attributed to abuse of tobacco and alcohol. Seitz found seventeen cases of ar- teriosclerosis between ten and twenty-seven years of age out of one hundred and forty-eight cases of arteriosclero- sis examined post mortem. Durante has described an instance of calcification of the inner layers of the tunica media of the pulmonary artery and the aorta in a prem- aturely born infant that lived only a few days. He re- gards this as antexample of a congenital atheroma. The parental history of the infant was unknown; death re- sulted from peritonitis due to infection of the navel. It is of course doubtful whether the sclerotic changes in the vessels of children and young persons depend upon a general primary weakening and loss of elasticity and contractility of the media. Special toxic and infec- tious influences may be at work in such cases, the sclero- sis being the result of inflammatory and other lesions in the media. Statistics show that men are more frequently affected with angiosclerosis than women. Edgren’s statistics give twenty-one per cent. of arteriosclerosis in women and seventy-nine per cent. in men. Arteriosclerosis ap- parently develops later in life in women than in men. 102 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chronic intoxications and infections of various kinds are regarded generally as playing an important part in the etiology of angiosclerosis, but so far it has not been possible to make any etiological subdivisions of the dis- ease. Among the intoxications those due to alcohol, lead, and gout are of the first importance. Tobacco is regarded by clinicians as not entirely free from delete- rious action upon the arteries; Huchard thinks it exer- cises a special influence upon the coronary arteries. The precise mode of action of these substances can hardly be more definitely specified than that under the toxic influ- ences degenerative changes and weakening develop in the arterial wall, especially the media. Martinotti claims to have produced changes in the renal and cerebral arte- ries resembling arteriosclerosis by the injection of cam- phor, alcohol, and turpentine. Of the chronic infections syphilis is the most impor- tant. Edgren places syphilis first in the etiology of ar- teriosclerosis, which when due to syphilis tends to appear rather early in middle life. Arteriosclerosis upon a syphilitic basis does not appear to present any special features (see Syphilis of the Vessels, page 105). Infectious diseases in general appear to exercise a harmful influence upon the muscular and elastic parts of the walls of blood-vessels. Reference has already been made to the toxic and infectious forms of angeiitis and to the production of gelatinous plaques in the aorta by the injection into animals of bacteria and toxins. The closure of the vasa vasorum by inflammatory changes in the adventitia and the outer layers of the media would surely interfere with the proper nutrition of the inner layers of the wall. Thoma has shown that the strength of the arterial wall suffers in diseases of the most various kinds. The overfilling of the vascular system due to exces- sive eating and drinking and the increased pressure and strain upon the arteries in muscular work constitute another group of causes (Osler). According to Huchard and Edgren arteriosclerosis is inseparably connected with the pathogenesis of increased pressure. The rela- tion of angiosclerosis to the intravascular pressure is seen in the distribution of the disease in the vascular system. Arteriosclerosis sustains a double relation to renal dis- ease. An existing sclerosis of the renal and peripheral arteries may interfere with the nutrition of the renal parenchyma to a degree that parenchymatous degenera- tion and connective-tissue overgrowth result. On the other hand, a primary interstitial nephritis by raising arterial pressure may lead to connective-tissue growth in the intima. The Forms of Arteriosclerosis.—There is some confusion in the classification of arteriosclerosis. The various ana- tomical forms often are found connected by transitional stages. Thoma recognized two main forms, diffuse or secondary, nodularor primary. The former he regarded as due mainly to primary changes in the peripheral ves- sels and the capillaries and as consecutive to the increased peripheral resistance. The latter he regarded as the re- sult of primary changes of a degenerative nature in the media, and as localized especially in those regions where the pulse wave is high and strong. Councilman holds that the diffuse form is a distinct disease associated with widespread changes in the media, and he distinguished a third form, the senile arteriosclerosis, in which the le- sions are mainly degenerative, compensatory thickening in the intima being but little marked. Senile Artertosclerosis.—In this form the process is largely one of degeneration and calcification with but little thickening in the intima. It represents the general atrophy and degeneration of senility as they affect the arteries when even connective tissue has lost much of its power of proliferation. In this form the heart is not always hypertrophied; atrophy of internal organs may bemarked. The aorta and its larger branches are dilated irregularly, tortuous and elongated, the walls in general thinner than normal, stiff, and covered by calcareous plates or the seat of cavities containing grayish-yellow, grumous material—the detritus of degenerated, necrotic REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood-Vessels, Blood-Vessels, muscular and fibrous tissue. The cavities are sometimes called atheromatous abscesses; frequently the thin inter- nal membrane is ruptured and rough spots and areas arise (“atheromatous ulcers ”) in the tloor of which calci- fication may take place or thrombotic material accumu- late. In typical cases the aorta and other large vessels are changed into rigid calcareous tubes, the inner surface being rough, frequently fissured, and covered by fibrin- ous masses. The intima has lost its glistening appear- ance. The resulting deformities of the affected vessels certainly warrant the name arteritis deformans which Virchow applied to the disease. The relations of senile arteriosclerosis to thrombosis, senile gangrene, cerebral softening, and other consecutive changes in the body are discussed fully elsewhere. Diffuse Arteriosclerosis.—This is the more important form, and in it the lesions are widely distributed, embrac- ing all the arteries of the body. As pointed out by Councilman, contrary to the senile sclerosis, the sub- a of diffuse arteriosclerosis are generally in the prime of life. In twenty-seven cases of this disease studied by Coun- cilman, the youngest, a negro, gave his age as twenty- three; the oldest was sixty. Most of the cases ranged between forty and forty-five; fourteen were white and thirteen colored. The negro seems disposed to this dis- ease, In this disease there is a typical pathological picture. Most of the subjects who come to autopsy are strongly built, well-nourished, muscular individuals. As a rule, there is 110 oedema either of the face or of the lower ex- tremities. When cdema is present it comes on in the last few days or weeks of life. Heart hypertrophy is always present and may reach an extreme degree. In two of Councilman’s cases in which there were no valvular le- sions whatever, the heart in one weighed 850, and in the other 820 gm. The average weight was over 400 gm. The myocardium is firm and dark. Close examination often shows some degree of fibrous myocarditis, this de- pending on the degree of involvement of the coronary arteries in the general trouble. The heart hypertrophy may be confined to the left ventricle, but in most cases it is always associated with so much dilatation that the right ventricle also becomes hypertrophied. The dilata- tion may be so excessive as to affect the integrity of all the valves. Anatomical lesions of the valves are usually absent. There may be some extension of the aortic dis- ease to the aortic valves or to the aortic segment of the mitral valve, but the thickening so produced is not gen- erally sufficient to interfere with the functions of the valves. Thesupposed inflammatory changes in the myo- cardium described by Buhl and referred to by Thoma were not found by Councilman. The most marked changes are found in the aorta and the large arteries given off from this. The large arteries are more or less dilated, the dilatation in some cases starting in the aortic orifice and extending throughout the aorta and large arteries. This dilatation is seldom symmetrical through- out, but in addition to the general dilatation there may be here and there mere local dilatations. The branches of the arch are sometimes relatively more dilated than the aorta. There is elongation of the vessels as well. The aorta makes lateral curves and the normal curves of other arteries are greatly accentuated. In addition to the dilatation there is a general diffuse thickening of the arteries, which is often relatively greater in arteries the size of the radial than in the large vessels. In the large arteries the intima is roughened by projecting elevations, which are frequently distin- guished by differences in color and consistency. They may be of a pearly, transparent color and very hard, in both color and consistency similar to cartilage. They may be of an opaque, whitish-yellow color, and the centre soft and pultaceous. On incising such places a soft, white, mortar-like mass escapes. We may find irregular, ragged excavations, often covered with fibrin, showing that the softening has extended through the intima of the vessel during life. Similar areas of soften- ing and degeneration may be found in the diffusely thickened intima. There may be more or less calcifica- tion which is usually confined to the projecting eleva- tions, but this never reaches the same extent here as in the senile form. There are frequently longitudinal folds and puckering of the intima as though due to the contraction of the vessel after death. The two essen- tial alterations are various degenera- tive changes in the media and a growth of tissue in the intima. The degenerations in the media are shown in various ways. Sections of the fresh artery show some fatty degeneration, but this does not play the chief part. The most common change seems to be ne- crosis and hyaline degeneration (Figs. 629 and 630). The muscle cells lose their nuclei and the whole muscular coat is changed into a solid homogeneous mass. The elastic fibres between the muscle lamine are frequently broken up and disappear; these changes probably appear early in the process. In some sections of the dilated carotid, for instance, the media as such may not be recognized, the whole artery being changed into a dense, thick mass of sclerosed connective tissue. This atrophy of the me- dia is always best marked opposite the points of greatest thickening of the intima. The tissue composing the thickened intima consists of thick layers of dense con- nective tissue, which not only in consequence of the poor nutrition which it has, but also in consequence of the pressure to which it is subjected, is particularly prone to degenerative changes. The tendency to de- generative changes, however, is not so marked here as it is in the senile form. This diffuse arteriosclerosis that Councilman describes agrees best with the form which Thoma has described as secondary arteriosclerosis, and in which he considers FIG. 629.—Diffuse Arteriosclerosis. Renal ar- tery. Weigert’s elastic-fibre stain. I, Inti- ma With new elastic fibres; M, media, the seat of hyaline degeneration ; no elastic ele- ments; A, adventitia with increased num- ber of elastic fibres. > 150. Fic. 630.—Selerosis of Anterior Tibial Artery. Gangrene of foot from thrombosis. I, Fibrous intima; E, elastic lamina; M, media with hyaline degeneration and calcification ; A, adventitia; D, be- ginning degeneration in intimal thickening. Haematoxylin and eosin. X 100. ; that the changes in the large arteries are due to the resist- ance to the blood circulation that the diseased small ar- teries cause. Ina paper on the conditions of the vessels in Bright’s disease, which preceded his publication on the arteries, Thoma shows that there is an opposition to the passage of the blood, which is due primarily not to a narrowing of the calibre of the vessels by the thicken- 103 Blood-Vessels. Blood-Vessels,. BREGMANN’S TABLE SHOWING RELATIVE FREQUENCY OF ARTERIOSCLEROSIS IN DIFFERENT ARTERIES. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. THE Figures REPRESENT PERCENTAGES. Normal. Slight degree. Medium degree. Severe degree. distinction aden Brachial «,ccudaudecuses sieve 45 Carotid, internal....... 48 | Aorta, abdominal...... 16:| Wlnar .cicce pases 94 Tiiac, external... We eseess 42 5 | (Subclavian..meeasc vase AY Cerebral sas ven esate tees 15 | Tibial, anterior......... 92 Aorta, abdominal........ 36 Ulnar wires serceeninerecs 39 | Carotid, internal....... 13 | Subclavian........ Reese 4 Aorta, ascending......... 33 2| Tibial, anterior........ 37 | Aorta, ascending....... 18} Cerebralic .cgeeeeee te 87 Carotid, common......... P| SPlOHIG sancntree wosmente 46) JAXIDATY wesc swe cee 36)| ‘SUPCLAVIAN.« o.\ciccs rene 12 | Carotid, internal........ 87 Femoral, superficial...... 31 | Tibial,.anterior........ 45: | BPlONIC!: < feeeeiewrycer cas 29 | Tibial, anterior........ IL | "Radial. .85.0 cece AXMATY cto ccnb a eee 29 |: Bemoralieccace ace see 44 | Carotid, common....... Boi | POpPLILed ce aeaie ew aeleeeee 10'| Splenic 2) .jeste eee 82 Carotid, external......... Pe POPLLOBL pestrrectetren tate 44 i) Radial (seen cecm ncn 27 | Carotid, common....... 9 | PoplitealiGcssamecee meen 79 Poplitedloccuasceceie 21 | Aorta, ascending....... 41 | Popliteal cn sweeten eye a. I BUCTVOTEI iorereivlerots.eratesosstevecs 18 | Carotid, external........ 78 SpleniGiii-cedescccsseene ISs\ Brachial sesenmecsteceer 40 | Aorta, abdominal...... ZEW SDICMIC 28 cccre reir ecoteietale 7 | Axillary... .cemeeene 1 Radial Meas oetss. yeti 14 | Iliac, external......... 38 | Iliac, external......... 19 | Carotid, external....... 6 | Femoraly vc .aceseeeren 69 Carotid, internal......... NS He AM aryeeemeer cio eeeere 345) Cerebral: fa caccw cess SeELSs Redd Bl eee ra cara erkeecieteree 3 | Carotid, common........ 68 Gerebral st cane dances’ 13 | Carotid, common....... Bll | FOMOLAal ence x dco ninerts Le UUme etcterevopia elaccloteteters 3 | Aorta, ascending........ 67 Subclaviansncnecrecs cc 2 | SUDCIAVIAN. sac scons se 29 | Carotid, external....... IGS ARTA Vig cee cicet hele ate 1 | Aorta, abdominal....... 64 Tibial, anteriovsc.csuc.ce. 7 | Carotid, internal....... 2B Brachial cs, 150. disease; the lesions in the arteries and tissues form a pathological entity, and the primary lesion to which all the changes are due is a degeneration of the tissue of the media of both the large and the smaller arteries. 104 531.—Nodular Sclerosis of Aorta with Beginning Aneurism. Hzematoxylin and Weigert’s . The intima (1D) is thickened, contains parallel, wavy, elastic fibres, except at the point of the bulging; the media (M) is thinned, degenerated, the elastic ORDER OF FREQUENCY OF NODULAR AND DIFFUSE ARTERIOSCLERO- SIS IN DIFFERENT ARTERIES. (Bregmann.) 3 Nodular Form. Diffuse Form (in Thoma’s Sense). Abdominal aorta. Radial. Common carotid. Ulnar. Descending thoracic aorta. Anterior tibial. Internal carotid. Popliteal. Ascending aorta. Splenic. Arch of the aorta. 1 Superficial femoral. Cerebral. Axillary. Subclavian. External iliac. Common iliac. Brachial. Coeliac. Subelavian. Superior mesenteric. External carotid. Inferior mesenteric. Cerebral. Renal. Internal carotid. Coronary. Ascending aorta. Popliteal. Common carotid. External carotid. Abdominal aorta. Splenic. Axillary. Common femoral. External iliac. Posterior tibial. Superficial femoral. Deep femoral. Internal iliac. Brachial. Anterior tibial (below). Ulnar. Anterior tibial (above). Radial. Nodular Arteriosclerosis.—In the nodular or primary form of arteriosclerosis there are seen flat, button-like, hemispherical, yellowish or yellowish-white projections above the intima, especially about the orifices of the ar- terial branches. This is generally regarded as the result of the greater strain that this part of the artery is exposed to. The areas consist of new connective tissue and new elastic fibres in the intima, the underlying media being either fibrous, calcareous, or degenerated and necrotic: Thoma showed that the cast after filling the vessel with melted paraffin injected under the same pressure as that of the blood came out smooth, showing that in the tense vessel the intimal nodules fill defects in the media. The stage of weakening in the intima antece- dent to the intimal thickening is lia- ble to result in aneurism (Fig. 631). The new tissue soon becomes hyaline, fatty changes take place, and eventu- ally disintegration into fat drops, cholesterin, granular detritus gives rise to softening. The degeneration begins in the outer layers of the sclerotic thickening, but may extend inward until the epithelium lining the vessel is destroyed and a larger or smaller rough area due to loss of substance is formed. Calcareous infiltra- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood-Vessels. Blood-Vessels, tion may take place. More or less leucocytic and round- cell infiltrations occur around softened areas. The ad- ventitia may be unchanged, fibrous, or the seat of foci of cell accumulations. This form is possibly due to local, circumscribed areas of degeneration and weakening in the media produced by strain, by toxic and infectious lesions. Several French investigators have produced apparently similar plaques in the aorta of animals by injection into the circulation of bacteria, bacterial toxins and other substances, such as lead, uric acid, ete., with or without producing trau- matic lesions of the vessel wall. In some cases of this kind the lesions seemed to be the result of proliferation in the intima; in others there were mesarterial and peri- arterial inflammatory foci about the vasa vasorum. In goitre of all forms, Jones found degenerative and sclerotic changes in the arteries of the thyroid and its capsule. The changes occurred apart from general arte- riosclerosis and were found quite marked in eighteen out of twenty cases examined. The vessels were abnor- mally friable. The internal elastic coat was granular, broken across, and calcified; in one case it had changed into a calcareous plate; connective-tissue thickening of the intima associated with the formation of new elastic fibres had resulted, followed by hyaline degeneration. The Distribution of Angiosclerosis.—The relative fre- quency of angiosclerosis in the different parts of the cir- culatory system has been studied by Bregmann, Sack, and others. The arteries are more frequently involved than the veins, although the study of phlebosclerosis has been rather insignificant as compared with the amount of attention paid to arteriosclerosis. ° Arteriosclerosis in general is more frequent in the ves- sels of the extremities than in the aorta and its branches of the first and second order; it is most frequent in the arteries of the leg and forearm, beginning first of all in the anterior tibial. This is explained on the score of the general lateral hydrodynamic pressure to which these vessels are exposed on account of posture in addition to the general hydrodynamic pressure. Arteriosclerosis of the pulmonary artery is exceedingly rare as compared with the frequency of the process in the aorta. In chronic tuberculosis of the lungs, emphy- sema and other diseases resulting in atrophy and destruc- tion of lung tissue naturally give rise to more or less compensating endarteritis. In Sauné’s thesis are collect- ed twelve cases of sclerosis of the pulmonary artery; in seven, emphysema was present. It is suggested by Laache that the carbonic dioxide may tend to prevent the development of arteriosclerosis, although the mode of action is not clear at all; probably the more important factor is the low pressure in the pulmonary artery as compared with that of the aorta (Laache, Frankel, Sauné). Laache has described an instance of sclerosis with ath- eroma of the pulmonary artery that clinically presented the symptoms of congenital heart disease (“morbus ceeruleus”); there were hypertrophy of the right ven- tricle, marked nodular condition of the intima, and dila- tation of the pulmonary artery. Apparently the sclerosis in this case was due to weakening of the arterial wall. Romberg has described a similar case. He found but one similar case in the literature, a case of Klob’s. The striking blueness of the skin in Romberg’s and Laache’s cases—in both instances it led to diagnosis of congenital heart disease—is difficult to explain. Huchard and von Schroétter describe each a case of sclerosis in the pulmonary artery associated with pressure upon it by aortic aneurism. Edgren attributes pulmo- nary sclerosis in one case to patency of the ductus arteri- osus. Philebosclerosis.—The early observations on sclerosis of the veins were made by Hodgson, Rokitansky, Virchow, and others. Lobstein introduced the term phlebosclero- sis. Rokitansky described thickening of the intima and of the adventitia of the veins involved in varicose aneurism; and Virchow called attention to chronic en- dophlebitis in long-continued passive congestions; in both cases the influence of mechanical causes is quite evident. According to the careful studies of Sack the localiza- tion of phlebosclerosis is determined largely by the same factors as arteriosclerosis, and the tendency is to regard phlebosclerosis in many cases as a systemic disease, anal- ogous to diffuse arteriosclerosis, and due to general nutri- tional disturbances resulting in weakness of the middle coat. But it may appear as a local disease in consequence of local venous congestions, as, for instance, in the portal system in atrophic cirrhosis of the liver, and in the pul- monary veins in mitral stenosis. As will be seen from the adjoining table of Sack, phlebosclerosis attacks espe- cially those vascular provinces in which the venous press- ure varies greatly in different positions of the body, and in which the activity of the voluntary muscles favors the venous flow to relatively but a slight extent. Now every obstruction to the venous flow hinders also the arterial flow, though in a much smaller degree, and un- doubtedly phlebosclerosis in some cases precedes arterio- sclerosis. Sack showed by the statistical method that the two diseases are closely related. There is need of further study of these questions. The important relations of phlebosclerosis to varicose eink ae of the veins are discussed under Varicose eins. SACK’S TABLE SHOWING THE DISTRIBUTION OF PHLEBOSCLEROSIS. 2 Number Frequency eae with of disease examined phlebo- in per- ; “| sclerosis. | centages. Ve JUQularnintoys acc outecie te es 20 7 35% Wis DEAGHIAT IS ea sicccncceh rate tele 55 4 7 Ve COPNALICH fc a's.cleiv.c o109.0.0 06 Fe 6 3 50 We DESLLAIR Are feclevera elatarse cies. sre wislele fi 4 57 Vis RAGHIAD So c)< ctvrsswie:s ti maiee mists 52 0 0 VS WINAE! ccissscitetn sete earls 58 0 0 Wis WiACAOXbscicc cc clsleceeatiaes ce 61 2 38 VSfemorali esas snececoeeeedcws 67 51 76 Vie PODIILCAI ere ctetsieieierenteinen etre tarays 72 65 90 Vie SDN NOG 2. ca cocince ciinetesees 55 50 91 Waersapha Dare tec desiainee rete 14 13 93 Va tibial anton vores viclossictl delet oe 88 24 re Sclerotic veins are elongated and of varying calibre. They present constrictions and dilatations, the dilatations. amounting in some cases to well-marked pouches filled and distended with blood. In the severer forms of the disease the vessels are curved upon themselves, and if superficial, they can be rolled under the finger like a cord. The valves are insufficient, either from retraction of their leaflets or from adherence to the side of the vein. When the vein is cut open its walls show differences in thickness, at one point being strong enough, perhaps, to gape open like an artery, at another collapsing as a vein usually does. At times, portions of the veins show cal- cified plates and ulcerous spots, resembling in each case those so frequently found in arteriosclerosis. The most. marked changes take place in the intima and the inner part of the media. The coats are thickened and pre- sent points of fatty changes and of coagulation necrosis. often infiltrated with lime salts; at other points athero- matous débris may have formed. SYPHILIS.—Some of the first observations on syphilis of the blood-vessels, as it affects the arteries at the base of the brain, were made by Virchow and Lancereaux. A good anatomical description of syphilitic arteritis was given by Allbutt in 1868. In 1874 Heubner published a. study of fifty cases of syphilis of the cerebral vessels, in which he endeavored to establish a primary endothelial proliferation (“arterioma”) as the specific form of arte- rial syphilis, the virus acting directly on the intima. In this he was opposed by Baumgarten, who, while not denying that syphilis causes endarteritis, yet claimed that the only arteritis histologically characteristic of syph- ilis begins in the lymph spaces of the adventitia, and results in a gummatous periarteritis. Kdéster,.Fried- liinder, and others supported Baumgarten’s view, and 105 Blood-Vessels. Blood-Vessels,. Friedliinder regarded Heubner’s endarterial proliferation as indistinguishable from endarteritis obliterans in gene- ral. According to this view the virus acts principally upon the adventitia through the vasa vasorum and the lymph vessels, the inflammatory process extending in- ward. Syphilis of the Smaller Vessels.—At the present time the general teaching is that syphilis of the smaller vessels occurs either as an independent process or as part and parcel of a local syphilitic infiltration; von Zeissel and other syphilologists state that primary vascular syphilis is one of the rare localizations of the disease. In the pri- mary form the vessels involved usually present yellowish- white or grayish thickening of the adventitia and the intima. A smaller vessel, such as a cerebral artery for example, may be studded with translucent or whitish, circumscribed patches, more or less cartilaginous in con- sistency and non-calcified; or a certain length of the The vessel may be transformed into a whitish cord. tendency to fibrous oblitera- a tion of the lumen is_ pro- nounced, but in the earlier Se Beit Oa Re et 2 ’ Se bee REA ESSE = ea Ra = Fic. 632.—Gummous Arteritis. Great intimal thickening with small cellular areas—gummata. At a, perivas- (From Nothnagel’s ** Specielle Pathologie und Therapie,”’ 1899, xv., p. 147.) cular infiltration of intima. stages the proliferation in the intima is richly cellular and vascular. This is the syphilitic endarteritis of Heubner. It is now generally held that this form can- not be distinguished either microscopically or macro- scopically from certain thickenings of non-syphilitic origin. The occurrence of obliterating endarteritis in circumscribed form in youthful persons is regarded, however—and as unquestionably so when associated with gummous nodules—as in the majority of cases the result of syphilis. The new tissue in the intima may contain vas- cular spaces. The elastic layer is greatly thickened and folded. Bands of elastic fibres appear in the thickening, and their development is ascribed by Abramow and Haga as due to a splitting up of the old membrane by the growth of fibrous tissue between its layers. But it is also probable that new elastic fibres form; at all events, that is not impossible. A reduplication of the elastic layer is regarded by Wendeler as marking each standstill of the process. The elastic elements do not appear to differ in their behavior from that seen in endarteritis obliterans in general. At other times the vessels are surrounded either with nodular, cellular infiltrations or dense cicatricial tissue. In the primary syphilitic lesion there is marked periarte- 106 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. rial infiltration, which is surrounded by an external ring of elastic elements, probably part of the walls of the perivascular lymph spaces in which the cellular prolif- eration takes place. In later syphilitic foci, when the granulation-tissue formation is in the recent stage, there is cellular infiltration in the adventitia, media, and inti- ma. Distinct gummous nodules, either purely cellular (lymphoid and epithelioid cells) or with a granular, ne- crotic centre and a cellulo-fibrous periphery with giant cells, may be found in the vessel wall (Baumgarten’s gummous arteritis), most frequently in the adventitia. This is the only form of syphilitic arteritis that is histo- logically specitic (Fig. 682). The gummata develop especially in the adventitia, more rarely in the media and the intima. Occasionally a sin- gle cross section may show a series of nodules in the various layers of the wall. Later, when fibrous transfor- mation takes place, all the coats become fibroid, the me- dia atrophic. Gummous periarteritis and productive endarteritis are often more or less intimately associated, especially when they occur as consecutive processes in the midst of syph- ilitic foci. The different appearances so often ob- served are explainable in a measure by the degree and the duration of the disease. Syphilitic arte- ritis differs from arterio- sclerosis by its circum. scribed occurrence and by the tendency to organiza- tion and obliteration; fat- ty changes and calcifica- tion are not characteristic of syphilis. Most of the investiga- tions on syphilis of the .q@ smaller arteries concern the cerebral. The appar- ent frequency with which the cerebral vessels, es- pecially at the base, are affected by these processes is explained as in part the outcome of the great in- terest that clinicians take in all the phases of cere- bral syphilis, and perhaps also because the basal ves- sels are constantly bathed in cerebro-spinal lymph. The anterior cerebral ar- teries—the cerebral branches of the internal carotid—are the ones especially involved. But syphilitic vasculitis as an independent process occurs elsewhere. In the spinal cord both arte- ries (Marinesco, Pick) and veins (Lamy, Orlowsky) may be involved. The coronary arteries, the arteries of the extremities, the splenic, the retinal, the mesenteric, and the adrenal (Weichselbaum) may be diseased more or less extensively as well. According to Urlich, Palma, and Birch-Hirschfeld, syphilitic changes in the coronary arte- ries may be primary or consecutive, the left coronary ar- tery being affected more frequently than the right. In Abramow’s cases there were circumscribed nodules in the walls of the arteries of the extremities and of the intimal organs, the cerebral being spared. In some the appearances described by Heubner predominated; in oth- ers, a more diffuse cellular infiltration with gummous nodules, especially in the adventitia, the muscular coat showing a granular disintegration. The destruction of the media by cell proliferation beginning either in the adventitia or the intima had resulted in places in aneu- rismal dilatations. Some of the appearances presented resemble not a little those of periarteritis nodosa. Von Zeiss], Lomokowsky, and Haga describe syphilitic arteritis of the extremities. In Haga’s case the vascular REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. disease resulted in spontaneous gangrene; this form of spontaneous gangrene seems quite frequent in Japan. Haga reports thirteen cases, in all of which the vessels of the affected extremities presented the same changes. The vascular lumen was obliterated either as the result of successive intimal thickenings, due to the production of a vascular new tissue solely, or from thrombosis. The media was thickened. In nine of the thirteen cases there were focal accumulations of round cells about the vasa vasorum, and in some instances cellular nodules were present in the media and the intima (gummous arte- ritis). Quite similar changes were observed in the veins. Scriba suggests that in some cases this arteritis is the re- sult of congenital syphilis. Von Zeiss] and Langenbeck describe syphilitic arteritis of the brachial artery that was healed by antiluetic treat- ; ment. Syphilis of the Aorta and Larger Vessels.—Isolated in- stances of gumma in the walls of the larger arteries, es- pecially the pulmonary, have been described by Weber, Wagner, Virchow, and others. Weber describes a gum- ma as large as a bean in the pulmonary artery, beginning in the media under the intact intima and causing great narrowing of the lumen. Syphilitie Mesarteritis.—Wagner, Hertz, Backhaus, Doehle, Heller, and others describe a primary sy phi- litic mesaortitis. _Macroscopically the intima presents circumscribed fissured and furrowed areas and depres- sions, which occur in groups especially at the beginning of the aorta and near the origin of the larger vessels. Elsewhere the intima may be smooth and normal or the seat of sclerotic changes. The media in such areas may be wholly absent or replaced by a thin layer of scar tis- sue. Microscopically there is proliferation about the vasa vasorum which may show obliterating changes, and there may be more or less distinct gummata with necrotic centres (Heller, Backhaus) as well as cicatricial areas with thickening of the intima and retractions, giving it the peculiar linear and irregular pit-like depressions that are regarded as characteristic of specific mesaortitis. Foci of small-celled infiltration, as well as diffuse fibrous changes, are present in the adventitia. These changes may be combined with ordinary arteriosclerosis. Back- haus states that of ninety-nine syphilitics examined at the Kiel Institute, seventeen showed mesarteritis. Doehle de- scribes a typical case in asyphilitic woman, aged twenty- five. Belfanti describes beginning gummous nodules in the aorta with marked circumscribed thickenings in the intima. Irregular ulcerations in the aorta with callous margins are also recorded as of syphilitic origin. Bol- linger has also described a gummous form of endarteri- tis. All seem to agree that the presence of circumscribed areas of fibrous attenuation of the aortic wall, associated with more or less dilatation, may be regarded as the re- sult of syphilitic mesaortitis; the changes are observed not rarely in rather young persons; there are often dis- tinct syphilitic lesions in other organs, and the changes in the aorta certainly do not correspond to those of ordi- nary arteriosclerosis. It is upon the basis of such lesions that aneurisms in young syphilitics probably develop. I have seen two cases of multiple, small sacculated aneu- risms in the beginning of the aorta that originated in fibrous mesaortitis; in both cases were areas of marked fibrous attenuation without much compensating fibrous thickening in the intima. Syphilis is also regarded as playing an etiological role ‘of a more general nature but of great impor tance in the vulgar form of arteriosclerosis. The occurrence of arte- riosclerosis and of arteriosclerotic aneurism in young ‘syphilitics is rather frequent and is generally known. On account of the many complex factors that enter into consideration in arteriosclerosis the exact role of syphilis is hard to define. Syphilitie Phiebitis.—Mch that has been said of syph- ilis of the arteries is applicable to syphilis of the veins, and especially as regards the secondary changes that occur in smaller veins in the midst of larger syphilitic foci. Dowse briefly refers to obliterative changes in the Blood-Vessels, Blood-Vessels, posterior cerebral sinuses in a gummous pachymenin- itis. Oedmanson, Winckel, and Birch-Hirschfeld described diffuse and circumscribed endophlebitis of the umbilical veins of congenital syphilitics. Schiippel has described a gummous pylephlebitis in congenital syphilis, and Bow- man attributes certain cases of thrombosis of the stem of the portal vein to syphilitic periphlebitic changes. Huber found intimal thickening with petrification in the veins of the extremities of a syphilitic girl twenty-two years old. In congenital syphilis there frequently occurs an oblite- rative vasculitis of the umbilical vessels which was first described by Oedmanson. Schiippel has described peri- pylephlebitis in a syphilitic infant, and in 1864 Virchow observed an ossifying endaortic process in a girl of eigh- teen with congenital syphilis. The vascular changes Sof the lesions of congenital syphilis in the internal organs resemble those of the acquired disease. Reference has been made to Scriba’s view that spontaneous gangrene may be caused by an arteritis of neon ADy. sy philitic origin. TUBERCULOSIS.—The older pathologists, such as Roki- tansky and Virchow, regarded the blood-vessels as im- mune to tuberculosis. The demonstration by Weigert in 1877 that acute general miliary tuberculosis results from the tuberculous invasion of either a blood-vessel or the thoracic duct put an end to this theory. So thoroughly did Weigert demonstrate this course of events that when the tubercle germ was discovered a few years later he could say truthfully that it was necessary only to sub- stitute bacillus for poison in order to make the report of his investigations conform fully to the new require- ments. Tuberculosis of the walls of blood-vessels may result from the extension of the process from adjacent tubercu- lous foci. This may occur in the arteries and veins. In case the lumen is not closed by productive endovasculitis and thrombosis, the infiltration in the vessel wall on case- ation and disintegration may give off tuberculous mate- rial and bacilli to the circulating blood. This leads to embolic or miliary tuberculosis of the corresponding capil- lary district. Im the case of the pulmonary vein, the general circulation becomes infected; in the case of a sys- temic vein, miliary tuberculosis of the lungs results; and if it concerns an artery, miliary tubercles may spring up in its capillary district. Tuberculous and suppurative destruction from without of the branches of the pulmo- nary artery exposed in tuberculous pulmonary cavities may so weaken the wall that aneurismal dilatations de- velop (“erosion aneurism”). Many of the copious hemor- rhages in advanced pulmonary phthisis result from the rupture of aneurisms of this nature. Dittrich, Kamen, and Sigg have described tuberculo- sis of the wall of the aorta due to direct extension. In Dittrich’s case an adherent lymph gland communicated the disease to the thoracic aorta, the intima of which pre- sented an oval defect with elevated ridges, a continuous tuberculous process traversing the aortic wall. Kamen’s case was of similar origin, the vessel presenting a dilata- tion with rupture of the wall. In Sigg’s case a tubercu- lous lung was adherent to the aorta, which presented a bulging corresponding to the caseous replacement of its wall, the caseous area being covered internally by a thrombus. When tubercle bacilli reach the circulating blood they sometimes become implanted upon the intima of larger vessels such as the aorta. Weigert, Flexner, Hanot and Levy, Stroebe and Blumer have described pinhead-sized intimal, aortic tuberculous masses. Blumer describes two instances of intimal tuberculosis of the abdominal aorta; in one of the cases there were several minute nodules of characteristic structure. The sclerosis of the aorta present in both cases did not play any part in de- termining this localization. In all of these cases the infection took place directly upon the intima and not through the vasa vasorum or the lymphatics of the walls of the artery. The tuberculous masses appeared as if 107 Blood-Vessels, Blood-Vessels, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. they had been fastened upon the intima. The surface of such areas may contain tubercle bacilliin large numbers. According to Cadéac tuberculous aortitis is not un- common in cattle. Ihave recently studied a tuberculosis of the aorta ina dog. A large nodule devel- oped in the wall of the aorta near the heart, producing such weak- ening that a small bulging had resulted. The relation of tu- berculosis of the blood- vessels to general mili- ary tuberculosis is discussed elsewhere. At this time it is suffi- cient to say that tuber- culosis of the intima of blood-vessels or of the thoracic duct or tuberculous endocar- ditis constitutes an es- sential, intermediate stage in the develop- ment of acute general miliary tuberculosis. It is in the tuberculous areas that result from infection of the intima and of the endocardium that the germs muiti- ply so freely that masses are thrown into the general cir- culation and produce on lodgment in the internal organs the numberless nodules characteristic of general miliary tuberculosis. There is no satisfactory evidence that tu- bercle bacilli multiply in the blood; hence miliary tuber- culosis means the setting free into the circulation at one time of large numbers of bacilli (Weigert, Benda, Gay- lord). The vascular changes in tuberculous leptomeningitis are interesting and well marked. There is a tuberculous endarteritis characterized by the formation of intimal tu- bercles and a diffuse subendothelial intimal proliferation (Figs. 683 and 684), probably induced by the implantation of tubercle bacilli from the blood. From the intima the infiltration may spread into the muscular coat and the adventitia and the whole wall may undergo caseous and hyaline degeneration. Occasionally, though rarely, the intimal process so weakens the wall that small, local dila- tations take place—a species of mycotic aneurism. Pro- liferation in the adventitia may invade the media and the intima and the whole wall of the arterial segment may undergo degeneration. In tuberculous leptomen- ingitis the muscularis oft- en presents the hyaline degeneration described by Guarnieri and others. The epithelioid cells that con- stitute such a prominent feature of the intimal pro- liferation undoubtedly or- iginate from the subepi- thelial connective tissue rather than from the epi- thelial lining, which ap- pears to remain intact un- til caseation takes place. Plasma cells and phago- cytic cells are also present. In this form of tuber- culosis adjacent extravas- cular and arterial foci fre- quently extend to the veins (Fig. 635). Banti describes a case of general tuberculosis in which nearly the whole length of the superior vena cava was completely filled by a mass of neoplastic tuberculous tis- sue which projected into the right auricle.* Fic. 633.—Perforation of the Elastic Layer by Caseous Intimal Foeus, Infil- tration into Media and Adventitia, and Beginning Aneurismal Bulging. Note beginning subendothelial prolifera- tion in opposite wall from tubercu- lous leptomeningitis. (Hektoen, The pe of Experimental Medicine, vol. i. 634.—Subendothelial Intimal Proliferation with Multinuclear FIG. Giant Cell. From tuberculous leptomeningitis. (Hektoen, The Journal of Experimental Medi- cine, Vol. i.) * Migge: Virchow’s Archiv, Bd. 76. 108 AcTINOMycosIs.—As actinomycosis spreads through the tissues by direct extension, no anatomical structure is absolutely secure from invasion, not even the blood-ves- sels. In metastatic actinomycosis the fungus gains en- trance into the circulation by the direct involvement of the walls of the blood-vessels in the vicinity of a local process. In the cases in which the point of invasion of the vascular system has been directly demonstrated it concerns some of the larger veins and cerebral sinuses. The meningeal sinuses and veins are frequently at- tacked in cranio-cerebral actinomycosis. In many cases of actinomycotic phlebitis the generalization of the proc- ess is undoubtedly prevented or delayed by consecutive thrombosis. Ponfick describes an actinomycotic proliferation which projected button-like into the lumen of the internal jug- ular vein; this invasion became the direct or indirect source of secondary foci in the heart, lungs, spleen, and brain. Ina case of primary pulmonary actinomycosis with extension through the diaphragm and into the spleen, Arnold Paltauf found the splenic vein infiltrated and thrombosed, the thrombosis extending into the portal vein; there were metastatic foci in the liver and in the brain. Liining and Hanau describe perforation in the hepatic vein in a secondary actinomycosis of the liver. In pulmonary actinomycosis with extension to the pleura and pericardium Habel found the base of the heart and the larger vessels surround- ed by a spongy tissue; just above the entrance into the auricle the superior vena cava presented a circum- scribed area in which the normal wall was substituted by a nodular mass of pale yellow color; the jugular veins were thrombotic. Abée describes an actino- mycotic perforation of the inferior vena cava. Begin- ning in the csophagus the process spread out in the prevertebral, mediastinal, and peripleural tissue, and invaded the diaphragm and the spinal column. The infiltration between the right lung and the dia- phragm surrounded the in- FIG. 635.— Focal Tuberculous Infil- tration with Giant Cell, Extend- ing through Wall of Vein with Secondary Thrombosis, Caused by Extension in Tuberculous Leptomeningitis. (Hektoen, The Journal of Experimental Medicine, vol. i.) ferior vena cava in the form of a layer, 3 to 4cm. thick, of a reddish, soft tissue rid- dled with confluent abscesses. At the point where the vein enters the auricle its lumen was materially narrowed, the intima roughened, covered by parietal thrombi and perforated by numerous yellowish suppurative foci; be- low, the vein was partially filled with a large softened thrombus. There were numerous metastatic actinomy- cotic abscesses in various parts of the body. Leprosy.—Leprous nodules sometimes occur in the walls of the veins in leprosy of the extremities. PERIARTERITIS Noposa.—This remarkable disease was described by Kussmaul and Maier in 1866. Cases had been observed previously by Pelletan in 1810 and by Ro- kitansky, but their descriptions were confined to the mac- roscopic appearances. Since Kussmaul and Maier fast- ened the attention upon the disease additional instances have been recorded, so that the total number of cases now is thirteen (von Schrotter). All of the cases have occurred in Central and Southern Germany except one—a Russian instance (Freund). The disease appears to attack young persons mostly between twenty and thirty; it occurs also in children. The male sex has so far furnished more cases. The symptoms are, generally speaking, those of a more or less severe toxic polyneuritis and polymyositis with constitutional and digestive disturbances, abdomi- nal pain, renal symptoms, etc. In nearly all cases a peculiar anemia and general weakness have been re- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Blood-Vessels, Blood-Vessels, corded. The whole course of the disease takes from six to twelve weeks, the termination as far as known being always fatal. In Kussmaul and Maier’s instance minute nodules were present in the skin of the face, neck, and up- perextremity. It is quite likely that in the future the dis- ease will be diagnosed during life, especially in instances with subcutaneous nodules which might be excised and examined microscopically. Clinical observation has not brought out any common or striking etiological condi- tions. Syphilis has been present in some cases and deti- nitely excluded in others. The vascular lesions consist of nodular, eccentric, and more diffuse thickenings of arteries of the general size of the coronaries and hepatic and smaller; the swellings are grayish and grayish white in color, vary in size from pinhead to pea and larger, occur especially at the branch- ings, but also in the course of the arteries both when free and intraparenchymatous. The distribution and num- ber of the swellings, usually present in great numbers, vary somewhat in different cases (Weichselbaum and Thompson); the favorite locations are the mesenteric (including the intraparietal branches of the gastro-intes- tinal tract), and the coronary, then the muscular, intra- neural, renal, hepatic, splenic, bronchial, and subcutaneous. Nod- ules have also been described at the ori- gins of the intercostal branches of the aorta and of branches of the crural and popliteal arteries. It is note- worthy that up to this time the veins have not been involved (Fig. 636). The histogenesis of the arterial lesions, which are of an inflam- matory nature associ- ated at times with aneurismal dilatations, fibrous tissue forma- tion and thrombosis, is not agreed upon. Fletcher, von Kahlden, and Freund regard the process as primarily inflammatory, due to the action of some un- known substance, which reaches the ad- ventitia by way of the vasa vasorum. ‘This view is supported by the presence, in Fletch- er’s case, of nodules upon the vasa vasorum and by the microscopic appearances in the early stages of the process (Freund). Accordingly, the inflamma- tory round-cell infiltration, which appears to be of a non-specific type, begins in the adventitia and extends through the media to the intima, producing in the last marked cellular accumulations between it and the media. As a result of the inflammation the muscu- lar coat undergoes a circumscribed hyaline degenera- tion, and hyaline material, probably of exudative ori- gin, also appears in the subepithelial layers. There are not many polymorphonuclear cells in the cellular in- filtration, which consists largely of spindle-shaped cells with large nuclei. Freund did not find proliferation in the intima when the media was normal. Eventually the internal elastic coat and the media are so thinned and de- stroyed that circumscribed aneurismal bulgings of the vessel wall may occur, but the formation of aneurisms is not constant because the development of fibrous tissue may prevent dilatation. FiG. 636.—Periarteritis Nodosa. (After Freund.) Longitudinal section of a small muscular branch. a, Adventitia, greatly infiltrated with cells; b, foci of especially dense cell accumulations in adventitia ; ¢, normal media; d, degenerated media ; e, external elastic lamina, bulging outward ; f, internal elastic layer; g, remnants of internal elastic layer: h, proliferating intima. Others, like Weichselbaum and Chvostek, hold that the process is primarily an endarteritis, which extends to the outer coats. In the case of smaller arteries and of vasa vasorum this would seem to be the fact probably. It has been suggested that periarteritis nodosa is a pri- marily multiple tumor of the nature of lymphoma, begin- ning in the adventitia. Circumscribed accumulations of cells occur in the adventitia that resemble lymphomata; but the singular fact that the process is confined to arteries speaks against this view. The subsequent for- mation of fibrous tissue is also inconsistent with this theory. Meyer regarded tears in the media as the essential cause, and Eppinger has elaborated the theory that peri- arteritis nodosa is the result of the formation of multiple aneurisms on account of ruptures of the elastic elements, which are congenitally weak and imperfect. Eppinger proposes to call the disease congenital aneurism. The proliferation observed, in the adventitia and intima, which constitutes such a striking feature of the lesions, is regarded by Eppinger and the supporters of the aneurismal theory (von Schrétter) as secondary ; and the thrombi and hard fibrous masses sometimes observed are similarly explain- ed. Aneurisms are not observed in every instance of periarte- ritis nodosa; in Pelle- tan’s, Rokitansky’s, Eppinger’s, Weichsel- baum’s, and Meyer’s cases they were mark- ed. In Pelletan’s case sixty-three aneurisms were present. The de- velopment of aneu- risms is consistently ex- plained on the score of more marked inflam- matory and degenera- tive weakening of the arterial wall in some nodules than in others in which these proc- esses were not so rapid. Any evidence of a his- tological nature of a congenital structural imperfection of the ar- teries in | periarteritis nodosa has not been furnished. Eppinger’s theory does not satis- factorily explain the relative infrequency of involvement of the cerebral arteries, which would seem to be as liable to aneurismal dil- atations as other arteries, if not more so. The clinical course of the disease is also against this view. The histological appearances and the genesis of the changes as explained by Freund and others rather favor the view that periarteritis nodosa is a primarily inflam- matory process in the further course of which aneurisms frequently develop; but further studies are essential be- fore the question of the nature of this disease can be definitely established. Micro-organisms have not been found in the lesions. Syphilis has been suggested as the underlying condition. Graf finds histologically periarte- ritis nodosa resembles not a little Heubner’s endarteritis syphilitica; and the appearances described by Abramow in two cases of syphilitic arteritis involving many of the smaller arteries, except the cerebral, are also decidedly suggestive of periarteritis nodosa, the clinical symptoms of which were absent, however. The absence, in some cases of periarteritis nodosa, of all history of syphilis and the freedom of other organs from syphilitic lesions and 109 Blood-Vessels,. Blue Hill Min. Spring. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. their consequences are also against the specific theory ; and it does not appear that the vascular lesions of periar- teritis nodosa ever present nodular foci of cell accumula- tions with central necrosis such as occur in the gum- mous form of syphilitic arteritis. Periarteritis nodosa must be regarded, for the present, as a distinct disease, histologically and clinically. Syphilitic periarteritis should not be included under periarteritis nodosa, as is done by some writers like Mott in Allbutt’s “System.” Many of the clinical symptoms are evidently due to secondary lesions in the internal organs. Although the intramyocardial branches of the coronary arteries are generally involved, the myocardium itself usually pre- sents but slight changes. Whether bronchitis and other inflammatory changes in the lungs are directly secondary to changes in the bronchial arteries, the pulmonary being usually free (von Schrétter), cannot be stated. The mu- cous membrane of the gastro-intestinal tract has been found to be the seat of multiple ulcers and hemorrhages; the ulcers in the stomach being more of the nature of erosions while those in the intestines may resemble ty- F1G. 637.—Growth of Carcinoma into the Gastric and Portal Veins and the Radicles of the The posterior surface of the stomach, A, Cut end of gastro-duo- Latter, Secondary to Carcinoma of the Pylorus. which is turned so that the pylorus is to the left, is exposed. denal vein. phoid ulcers. These changes are regarded as the result of circulatory disturbances in the areas nourished by the affected branches, many of which become entirely oc- cluded by thrombosis. Enlargement of the mesenteric glands is usually present. The spleen may be the seat of infarcts, in various stages of absorption, caused again by the occlusion of terminal arteries. Pressure of the nodules in the intrahepatic branches of the hepatic artery on the bile ducts may cause jaundice (von Schrotter). Severe changes are produced in the kidneys. Multiple ischemic necrosis results from thrombosis of the affected arteries. Degeneration of the glomeruli, hemorrhages, parenchymatous and interstitial changes develop, due either to extension of the vascular changes or to the ac- tion of toxic substances in the blood. The changes in the peripheral nerves and in the skeletal muscles explain well the nervous and muscular phenomena observed clin- ically. The pressure of changed arteries upon adjacent nerves may cause degenerations, and in Freund’s case foci of degeneration in the nerves were found to corre- spond to nodules upon intraneural arterial branches. The development of nodules upon the intramuscular ar- teries gives rise to granular and fatty disintegration of the muscle fibres and to waxy changes. In Weichselbaum’s case the rupture of an aneurism, 2 cm. in diameter (the largest so far recorded in periarte- 110 ritis nodosa), upon the arteria profunda cerebri gave rise: to hemorrhage. Tumors.—The primary tumors composed of blood- vessels—the various forms of angioma—are described in. the article on Zumors. Here is described also the part that blood-vessels play in the general dissemination of the malignant tumors. Primary tumors rarely develop in the walls of blood-vessels. Brodowski has described a primary sarcoma of the thoracic aorta, which started in the adventitia and extended through the muscular coat. and into the intima; the sarcomatous infiltration of the intima produced a marked thickening of the latter. I have described an interesting pedunculated out- growth of the intima of the basilar artery, which at that. time was regarded as a fibroma. It is possible, however, that the outgrowth in reality was the result of an endar- teritic proliferation of inflammatory nature. Several instances of myoma, fibroma, and sarcoma. have been described as primary in veins (Orth), Secondary tumors occasionally occur in the walls of the: blood-vessels. Quincke, in “Ziemssen’s Encyclopedia,” cites an instance, described by Broca, of cancer at the root of the aorta with rupture into the pericardium. Fried- rich describes metastatic nodules of a. papillary cystocarcinoma of the ovary in the wall of the thoracic and abdom- inal aorta and the renal artery ; here the metastases evidently occurred through the vasa vasorum. The nodule in the: thoracic aorta ruptured into the lumen of the vessel. Extensive intravascular growth of malignant tumors, especially in the veins, takes place in the case of sar- coma of various kinds, especially of the bones, in adrenal tumors of the kid- neys, etc. Intravascular growth of this kind has extended from the renal vein, for instance, to the heart. In carcinoma of the stomach I have observed an extensive intravenous. growth of the tumor resuiting in a kind of carcinomatous injection of all the veins about the lesser curvature of the stomach and of the portal vein (Fig. 687). Orth observed the entire venous plexus of the dorsum of the foot filled with sarcomatous masses. Norica and Haret* describe a carci- noma of the stomach with metastases in the mesenteric, mediastinal, and deep cervical glands, followed by carcinomatous invasion and thrombosis of the superior vena cava, the two brachio- cephalic, subclavian, and internal jugular veins. In 1885 Oulmont collected nineteen cases of obliteration of the superior vena cava. He distinguished two groups, namely, obliteration by pressure and obliteration by con- cretion. The first group comprised five cases due to can- cer of the mediastinum or of the lung, two cases due to tuberculous lymph glands, and four cases due to aortic aneurism. The second group included five cases of thrombosis and three cases of cancerous invasion. Com- by and Rendu each report a clinical case in which aneu- rism of the aorta was thought to be the cause. I have examined post mortem a case of this kind, in which an aneurism of the ascending aorta compressed the superior vena cava, which was wholly obliterated by the forma- tion of fibrous tissue in the intima. The occlusion took place gradually and resulted in a great dilatation of the subcutaneous thoracic and abdominal veins which for years furnished routes for collateral circulation. Le- tulle lays stress on occlusion of the large veins of the neck and mediastinum on account of propagation of car- cinomata of the glands, the thyroid, and the thymus. *Bulletins et mémoires de la Société Anatomique de Paris, 189% Ixxiv., 861. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. pine ¥ill min, Blood-Vessels, Spring. Gallavardin reports thrombosis of the large cervical veins in mitral stenosis. The extensive occlusion described by Norica and Haret has been equalled by the case of Reid only, which is included in Oulmont’s series. There was in Norica and Haret’s case dilatation of subcutaneous veins of the right side of the chest and abdomen, show- ing that the blood in the superior vena cava was diverted into the inferior by way of the azygos vein. This diver- sion furnished a sufficient collateral circulation. The condition of the thoracic duct was not examined. Ludvig Hektoen. LITERATURE. General. Allbutt: A System of Medicine, 1899, vii. Orth : Lehrbuch d. path. Anatomie, 1887. Von Schrétter: Nothnagel’s Specielle Path. u. Therapie, 1899, xv. Abnormities. Brooks: Journal of Anat. and Physiol., 1886, xx. Dowse: Transactions London Path. Society, xxvii., 11. Lancereaux: Traité d’anatomie path., 1881, ii., 948. Peacock : Malformations of the Heart, 1866. Rauehfuss: Virch. Arch., 1859, xvii., 376. Shaw, D. Lee: Aorta with Double Arch. Journal of American Medi- ical Association, 1897. Retrogressive Changes. Mallory, F. B.: A Contribution to the Study of Caleareous Concretions in the Brain. The Journal of Pathology and Bacteriology, 1896, Prey LO: Angetitis. Borchard: Beitrage zur primiren Endarteritis obliterans. Zeitschrift f. Chirurgie, xliv. Bollinger: Endophlebitis verrucosa im Pfortader eines Pferdes. Vir- chow’s Archiv, 1872, lv., 279. Boinet et Romary: Recherches expérimentales sur les aortites. Arch. d’Anat. Path., 1897, ix., 902. Chiari: Ueber die selbstandige Phlebitis obliterans der Hauptstamme der Venz Hepatic als Todesursache. Ziegler’s Beitrige, 1899, Vis J Fenger, Christian: Stenose af Ostium pulmonale og Arteria pulmo- nalis, forarsaget ved Vegetationer pa Pulmonalklapperne og i Arte- rien, oplyst ved et Sygdomstilfalde. Nordisk Medicinskt Arkiv, Band v., No. 4. Flexner, Simon: Perforation of the Inferior Vena Cava in Amoebic Abscess of the Liver. The American Journal of the Medical Sciences, May, 1897. Haga: Ueber Spontane Gangran. Virchow’'s Archiv, 1898, clii., 26. Hunter, John: Transactions of a Society for the Improvement of Medi- eal and Surgical Knowledge, 1793. Jones: Ueber die Neubildung elastischer Fasern in der Intima bei Endarteritis. Ziegler’s Beitraige, 1898, xxiv., 458. Deutsche Angiosclerosis. Councilman, William T.: On the Relations between Arterial Disease bel ie Changes. Trans. Assn. of American Physicians, 1891, viteay bate Dmitrijeff : Die Veranderung der elastischen Gewebes der Arterien- wiinde bei Arteriosklerose. Ziegler’s Beitriige, 1897, xxii., 207. Durante: Athérome congenital de l’aorta et de l’arterie pulmonaire. Bull. et Mém. de la Soc. Anat. de Paris, 1899. Eberhardt, Alexander: Ueber den sogenannten kérnigen Zerfall und Querzerfall der elastischen Fasern und Platten in ihrer Beziehung zu den Erkrankungen des Arteriensystems, 1892. Epstein: Ueber die Struktur normaler und ectatischer Venen. Vir- chow’s Archiv, 1887, eviii. Gazert: Ueber den Fett und Kalkgehalt der Arterienwand bei oe und Arteriosclerose. Deut. Arch. f. kl. Med., 1899, Lil’, F Laache, S.: Om Sklerose af arteria pulmonalis og erhvervet ‘‘ morbus coeruleus.”? Norsk Magasin fer Lagevidenskaben, 1900, 1x., 51. Malkoff : Ueber die Bedeutung der traumatischen Verletzungen ven Arterien fiir die Entwickelung der wahren Aneurysmen und der Arteriosklerose. Ziegler’s Beitriige, 1899, Ixxv., 481. Peabody, George L.: Relations between Arterial Disease and Visceral Changes. Trans. Assn. of American Physicians, 1891, vi., 154. Sack: Ueber Phlebosklerosis und ihre Beziehungen zur Arterio- sclerosis. Dissertation, 1887. Sauné: De l’athérome et de l’artére pulmonaire. Thése de doctorat, 1877 dd. Thoma: Virchow’s Archiv, vols. xciii., xcy., civ., cV., CVi., Cxi., cxii., exiii. Syphilis. Abramow : Ueber die Veriinderungen der Blutgefasse bei der Syphilis. Ziegler’s Beitriige, 1899, xxvi., 202. d is Birch-Hirschfeld: Beitr. zur pathol. Anatomie der heredit. Syphilis. Arch. f. Heilk., 1875, xvi., 166. Bowman: Beitrige zur Thrombose des Pfortader-stammes. Deut. Arch. f. kl. Med., 1889, lix., 283. : Huebner: Die leutische Erkrankungen der Gehirnarterien, 1874. Huber: Ueber syphilitische Gefisserkrankung. Virchow’s Archiv, 1880, Ixxix., 573. Tuberculosis. Blumer, George: Tuberculosis of the Aorta. The American Journal of the Medical Sciences, January, 1899. Gaylord, Harvey R.: Critical Summary of Literature on Tuberculosis of the Walls of the Blood-Vessels and the Production of Miliary ie The American Journal of the Medical Sciences, July, Hektoen, L.: The Vascular Changes in Tuberculous Leptomeningitis, Especially the Tuberculous Endarteritis. The Journal of Experi- mental Medicine, 1896, i. Periarteritis Nodosa. Fletcher: Ziegler’s Beitrige, 1892, xi. Freund: Deutsche Arch. f. kl. Med., 1899, Lxii. Graf: Ziegler’s Beitrige, 1896, xix. Von Schrotter: Nothnagel’s Specielle Pathologie u. Therapie, 1899, xv., 3d. BLOUNT SPRINGS.—Blount County, Alabama. Post-OFrrice.—Blount Springs. Hotel. Access.—Via Alabama and Chattanooga Railroad, also vid Louisville and Nashville Railroad to Elyton. The springs are about thirty miles northwest from this station. The waters of Blount Springs may be classed as saline sulphureted. The springs are six in number, and are located in a triangular valley 1,580 feet above the sea level. ONE UNITED STATES GALLON CONTAINS: nee: Sweet Spring Solids. R. T.. Spring. No. 4. Brumby. Brumby. |Summers. Grains. | Grains. | Grains. Magnesium carbonate............0008 4.40 3.60 9.40 Calcium CAnDONRGiw. acciciscssie ccsiels sielere 6.80 4.48 5.7 Baru CarbOnalerenaneceicuiscm neta mayer Figen 91 Tron) Carbonate. Gs ceenalsss poses estes 1.92 1.12 3.19 Sodinmycarhbonates., sccrtescs ces usec nee Seite cinta Magnesium sulphate 1.60 2.40 on Calcium sulphate... ..3..cs.c8.6 aieteke HAD 1.27 Calcium phosphate........... Fuss Scie nace Trace. IPObASSIUMUeChIOTIOG ssc cninestavicdees a. oiee tear 7.07 HOdTMCNIOMAGS ccc cisslerectess veteiieene 32.32 30.88 23.21 Magnesium chloride...............065 6.00 Saisie 2.04 Moyo b te Eo BS Oe an Ran hucnnaccacosdcoODbaC antc Tone aaa Magnesium J0dide.......0.s0tereeee Sere hee 14 Magnesium bromide................0> Pirie eet 16 TACHA ayeterateroreratepsietelcisioieerstetcrsieicisiescstete Trace PA IULEVLS IA Neatece ous ctetaietatstotcloianersietersislea’ siecle aeafere i stehe Trace SUL CAH ele orc tele cfelererisin oteisiatsiste (ols weisielocteiste’e e Rae ene 2.44 SHC son, GaagenconcobdDAbb COSrObCurle AGns TOA esas letinccrewiais osiucWieloastesiel jets 53.04 42.48 55.55 Gases Cu. in. Cu. in. Cu. in CATT OWIC AGI ays arete ae clovatola\e:asofarelersietacei& 6.00 6.00 4.72 Sulphureted hydrogen...............- 14.96 12.56 30.67 ORY POMS encase nine sis wrclettiew ccteics See pee t +08 NitrO@ON Re tutawen tec ohne itecloes oun BGS seas os J. K. Crook. BLUE HILL MINERAL SPRING.—Hancock County, Maine. Post-Orricr.—Blue Hill. Hotels. AcceEss.— Via steamer from Portland, also by stage from Ellsworth, fourteen miles distant. The Blue Hill Mineral Spring is located two and one- half miles northwest of Blue Hili village, and about six hundred feet in perpendicular height above the base of Blue Hill Mountain. Its situation assures freedom from all surface impurities. The existence of the spring was noticed by Dr. Charles T. Jackson in his second report of the geology of the State of Maine, published in 1888. It was not until recently, however, that improvements were made. A handsome and commodious building has been erected for the comfort of tourists and visitors at the springs, and a large bottling plant established. An analysis by Prof. 8. P. Sharples, of Boston, resulted as. follows: ONE UNITED STATES GALLON CONTAINS: Solids. Sodium chloride .........scee0e Teese tints! s:2 ielesrale orarriere a ecstat Sodium sulphate....sseereseeessvees : Sodium carbonate..... EA OD ROAR EN Ot iica: EOE ITIGHOL E Calcium carbonate...... Riera Gialetectovete ctatetors sre tiers tatorek iniena arora 1.87 TTON) GBTDONAtE sou sansiesG aecashio a « pi ature soaeeica ep aaciie 59 Te tena Sop odbot Sees bbe ADU e ere Cobsog Rais ota bisee Sa 1.07 Organic matter oi... ccc cece senscscosccscnss Le yadunde Traces. Totals .vcseoe BL aS atideectlccn sleaies De aw ae e aie Sodan © S/G) Blue Lick Springs. Boil. This is an excellent table water, and it also possesses mild diuretic and tonic properties. It is used commer- cially. J. K. Crook. BLUE LICK SPRINGS.—Saline County, Missouri. Post-OFrFricE.—Marshall. Cottages at spring. AccrEss.—Viai Chicago and Alton, or Jefferson City, Boonville and Lexington branch of the Missouri Pacific Railroad to Marshall, thence eight miles by stage south to springs. Saline County, Missouri, is entitled to eminent distinc- tion as a water-producing district. Thousands of clear, pure-water springs of more or less volume are well dis- tributed over its surface. They are found in large num- bers along the Missouri, Blackwater, and Salt River bluffs, and at the base of the minor hills in all parts of the county, and are unfailing at all periods of the year. The most remarkable natural resources of the county, however, are its mineral waters, which for volume, variety, and medicinal value are among the finest in the country. Not less than two thousand mineral springs, some of them of immense flow, are found in the limits of the county. Some of these springs will, no doubt, take a prominent place among the health resorts of the country when they shall have been properly developed. At the Blue Lick Springs are more than thirty distinct fountains in a pretty valley at the base of picturesque wooded bluffs, all within a radius of thirty feet. The largest of the group, known as the “Gum” Spring, is an immense salt fountain of 57° F., which was formerly the site of extensive salt works, but is now the centre of a large bathing establishment. Nearby is the “Blue Lick” Spring, the most important of the group. Then there are numerous black sulphur, magnesian, chalybeate, and sweet springs, besides uncounted saline springs. Many of these have been analyzed by State Chemist Paul Schweitzer, who found in them the following mineral ingredients: Calcium sulphate. Barium sulphate. Calcium sulphite. Sodium sulphite. Ammonium nitrate. Magnesium nitrate. Calcium phosphate Alumina. Silica. Sulphur. Carbonic acid gas, large quantities. Sulphureted hydrogen gas, large quantities. Sodium chloride. Potassium chloride. Calcium chloride. Magnesium chloride. Lithium chloride. Calcium carbonate. Tron carbonate. Magnesium carbonate. Manganese carbonate. Magnesium bromide. Magnesium iodide. Magnesium sulphate. Potassium sulphate. Many of these ingredients serve to endow the waters with valuable remedial qualities. A complete qualita- tive analysis of the Blue Lick Spring, for which the col- lection is named, resulted as follows: ONE UNITED STATES GALLON CONTAINS: Solids. Grains Galeilim CAYDOVALCE Sat vivtleiaie'e sate icceleieielole alavera'olsistetnret stsievarare 57.84 IM ARONOSIUM SUID AKG acre leretarereis/e's planslsiarelcrertiels eiaieortere ots te 26.13 MAONESINM, ;CHIOTIAE iieiateissorelelore lejelcielereleievavacrmnieiers eveletstsiayeiste 10.94 Soditina Chloxvide See lioc tetas amtetre cvexteietetotererctetete palette 493.88 Potassiu Chloride en vce scien sieleteisters otis ainiain tote eicteversters 64 SLUG olka Tohurele sara ers eiaree acciale aveTecniele esarerers,apataletarate eieleferne tor elets 8.16 ATINMINAT Sy wep caters cletecie so esn leit aida tate cleetars clei te teicta 10.23 Ofeanic Miatleretes scene eae ciememittte nsec 2.48 MTOCAL Si ccale oleriviteliaic's aleve sie@ide is olaielcwintareretalaeiealeleaiotarets 610.30 Gases. Cu. in Free Carbonic acai ai vice a hice cncwils emveeiiebiee sielorelersts 53.22 Sulphureted Dy Grow@eu 3.) afe ais. miele oveteteislefersiainieiate Not estimated It will be seen that the waters are very similar to those of the Blue Lick Springs of Kentucky, for which these springs are named. The water is well adapted for the treatment of con- stipation, especially when due to engorgement of the portal system. On the other hand, it is also said to act beneficially in many cases of chronic diarrheea. It acts with advantage in many of the conditions due to a slug- gish liver, such as hemorrhoids, jaundice, etc. Being a very efficient diuretic, the water is useful in certain renal and bladder disorders. Within sixty steps of the Blue 112 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Lick Spring are three black sulphur springs; two hun- dred and fifty yards south is the Sweet Spring, which has been found to bea very efficient diaphoretic and diuretic. It is entirely free from sulphur and forms a very pleas- ant beverage. James K. Crook. BLUE RIDGE SPRINGS.—Botetourt County, Virginia. Post-OFFiIcE.—Blue Ridge Springs. Hotel and cot- tages. Access.—Via Norfolk and Western Railroad. The hotel is located near the railroad station. This resort has a picturesque location in the midst of the Blue Ridge Mountains, the elevation being about thirteen hundred feet above the sea level. The springs yield about one hundred and twenty gallons of water per hour, having a temperature of 52° F. the year round. The water has been analyzed by Prof. Henry Froehling, with the following results: ONE UNITED STATES GALLON CONTAINS: Solids. Grains Magnesium sulphate s..« «essa 0s oie +’ oe « «calls ue aerate 47.01 Caleitam Sulphate oseictes.0 -sieleiewisieitens a « eielelee eee ener enene 100.13 Sodium: SuUIPHAte.... ccervles se ses cece sehen slot een 37 Potassium SulpNate 5.5). sis). scicreosta a cle ole sieivinle ameter eta 65 Magnesttm Carbonate s:cciciccmccisse «sous semtienaeenmnten 1.61 Calcinm: Carbonate: ic. cite ows cles «ot eice clalene einer 3.96 Strontium carbonates. 0. cove cs wee osieeeu enter seieerete 29 Barilim: Carbonate... casas sis ce vcvjtelsss sdisve viv eet lea 02 Manganese: Carbonate iio: <) matrix between being partly calcified ; ¢, which occur at d, already formed bone; the osseous tra- this period. The beculze being covered with osteoblasts (¢), intermediary sys- except here and there, where a giant cell or osteoclast (f) is seen, eroding parts of the trabeculz; g, h, cartilage cells which have become sunken and irregular in shape. $ tems of lamelle, above described, as seen in transverse sections of long bones (Fig. 646), are, in many cases at least, the re- mains of older lamellze which have been partially ab- sorbed; the absorption spaces having been afterward filled in by new Haversian systems. What the conditions are whose fulfilment determines now an absorption and again a new formation of bone, or exactly what the origin 119 Bone, Bone. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. of the osteoclasts is, and what their relation to the osteo- blasts, we can, in the present state of exact knowledge, do little more than conjecture. Consult, for the bibliography of the histology, develop- ment, and growth of bone, Quain’s “ Anatomy,” vol. i. part ii., tenth edition, and the “Index Catalogue of the Library of the Surgeon-General’s Office, U. 8. A.,” vol. ii. T. Mitchell Prudden. BONE. (PATHOLOGICAL.)—Bone, like all tissues, is subject to a continuous waste and repair. New bone is constantly formed and the old absorbed; and while in the adult these processes may be very slight, under the in- fluence of pathological conditions they become very marked; hence the conditions known as pathological ap- position, absorption, and transformation of bone. Ap- position occurs by the formation of bone from the perios- teum. The deeper layers of periosteal cells become con- verted into large epithelioid cells, the so-called osteoblasts, which later become irregular in shape; the intercellular substance becomes calcified and thus new bone is formed. The new bone may be spread out over the surface of the old, and become firmly attached to it, or it may be limited toasmall portion of the surface of the bone. In the first case the process is called hyperostosis and exostosis; in the latter, the processes of new bone are called osteo- phytes. Absorption or resorption of bone occurs at the medul- lary surface and is due to the activity of the large multi- nucleated cells known as osteoclasts. Occasionally this may occur at the periosteal surface, and we have the surface of the bone becoming irregular and porous—osteo- porosis. This occurs occasionally in the very aged, in the bones of the calvarium, as the result of senile atrophy, or it may be secondary to inflammatory exudates, tumors, aneurisms, etc., which exert pressure upon the bone. Transformation of bone is brought about by a com- bination of apposition and resorption. By means of these processes the form of bones is changed to meet pathological conditions and changes in function. This is more particularly true of the size and direction of the columns of bone in cancellous structures. If the amount and direction of the load to be borne by the bone become changed, then will the thickness and direction of the columns of bone become changed in the direction of the static demand. By reason of this characteristic of bone, such great artificial deformities are produced as are seen, for instance, in the Chinese’ foot. Regeneration of bone is seen*following every fracture. Every solution of continuity in bone is followed by the formation of new bone, not only sufficient to replace the defect, but also enough to form a large mass surrounding the fracture (callus). In fractures of long bones, one differentiates an internal callus formed by the medullary structures, and an ex- ternal callus formed by the periosteum. This new bone or callus remains intact until the function of the bone is resumed. Later on, that portion of the callus which is not situated in the direction of the load-bearing lines becomes absorbed, and the form of the new bone, just as that of the old, becomes changed to meet the static de- mands made upon it by the function of the bone—7.e., that of bearing a load. Osteomalacia is a chronic disease of bone, occurring in adults and most frequently in puerperal women; it is attended by a progressive softening and absorption of bone beginning in the centre and extending outward. The process is followed either by fracture or by deform- ity of the bones affected. It differs from rachitis in this, that while in the latter we have a deficient deposition of lime salts in newly formed bone, in osteomalacia bone which is already formed is deprived of its earthy mate- rial and absorbed. The changes that occur in the bone are not due to any active process on the part of the bone tissue itself. There are no active changes to be discov- ered in the bone cells. The only thing to be found in the lacunee is the occasional presence of droplets of fat, which is evidence of a passive destruction of the bone cells. 120 In the medullary tissue, however, there are to be seen evidences of very marked, active proliferative processes. This is to be observed in the marrow of the long bones, in the medullary tissue of spongy bone, and also in the Haversian canals, which latter normally contain very lit- tle medullary tissue. This tissue is the seat of a marked hyperemia which has converted it into a bright red, succulent tissue, free from fat and extremely rich in pro- liferating cells. All the medullary tissue seems to have the appearance of the red marrow of infantile bone. This tissue pushes its way outward at the expense of the adjacent bone, first depriving it of its lime salts and later causing its complete absorption. Thus the compact bone of the diaphysis is converted into spongy bone by the enlargement of its Haversian canals; the trabeculee of spongy bone are absorbed. If the process continue long enough there remains little of the bone except marrow and periosteum; so that it has been converted into a soft, decalcified, sausage-like mass of marrow, that is held together by the periosteum with perhaps a thin, paper-like layer of bone beneath. The process may be distributed over a period of several years with occasional cessation. In such an event the medullary tissue loses its signs of active proliferation, the hyperemia diminishes, and the tissue appears as a yellowish, fatty mags, or as a pale, gelatinous, mucoid, semi-fluid material. In the latter event many of the cells have undergone mucoid degeneration, and if this has been extensive it may have led to the formation of mu- coid cysts. This period of quiescence may again give place to a renewed activity as before and to a further destruction of the bone. This process has a certain resemblance, in activity, to that of inflammation, but the phenomena that attend either acute or chronic inflammation of bone are never present. We never find either suppuration or the for- mation of new bone. The cause of decalcification of bone in this disease has been sought for chemically. Some investigators have found an excess of lactic acid in affected bones, and also: in the urine, and the solvent action of this acid has beem brought forward as the chemical agent which brings on decalcification. Other observers have failed to find this excess. The amount of gluten is diminished in the bones. affected. There has been found in the urine a peculiar albuminous substance supposed to be derived from the organic substance of bone. : The bones of the pelvis and of the spinal column are. most frequently affected, then come those of the thorax, and of the lower and upper extremities. The bones of the head are very rarely the seat of the disease; the teeth ‘are never involved. In the non-puerperal cases, the predisposing causes. are malnutrition and living in dark, damp houses. Osteomalacia has been observed in animals who are badly fed and stabled in dark, damp places. Osteomalacia is a comparatively rare disease. It is. rarely seen in England and America; it is more frequent. in Germany than in France. In some parts of Germany the disease is more frequent than in others; thus in the Rhine valley and in Southern Germany the disease is more common than in other districts. The preponderance of puerperal females affected is. very striking. Thus of one hundred and thirty-one cases. gathered together in the report of Letzmann, in 1861, eighty-five were in women who became ill either during pregnancy or during the puerperal period. Repeated pregnancy and prolonged nursing in poorly nourished women predispose to the disease. In all of these puerperal cases the disease began in the bones of the pelvis, and in many it was limited to that. region. It is therefore highly probable that the great. circulatory changes in the pelvis attending pregnancy have a decided influence on the causation of the disease. Fehleisen regards the disease as a reflex trophoneurosis. of the blood-vessels of bone, causing a dilatation and proliferation of the marrow at the expense of the bone, and having its origin in the ovaries. The removal of the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Bone, Bone, ovaries has been practised as a curative measure with some, though not universal success. Of forty-six non-puerperal cases, thirty-five were in women and eleven in men. These cases are, as a rule, more rare than the puerperal. Rachitis or rickets is a disease occurring in children, It is caused by improper food and bad hygienic surround- ZB Te crt ety =) : ty o * [Sto fon Gi Pkece =| Leereonsde J Fig. 647.—Section through the Line of Ossification of a Normal Femur from a Healthy Child. a, Hyaline cartilage; b, zone in which the cartilage cells are hypertrophied ; c, cells arranged in columns; d, columns of hypertrophic cartilage; e, zone of temporary calcifica- tion; f, zone showing beginning of medulla; g, first bony forma- tion; h, spongy bone; 7, blood-vessels; k, osteoblasts. (After Ziegler.) ings, and is attended by a disturbance in growing bone whereby the reabsorption of bone is increased, the calci- fication of incompletely formed bone is diminished, and the formation of so-called osteoid tissue is excessive. It has been aptly and briefly described by Jenner as “an increased preparation for ossification but an incomplete performance of the process.” The disease is most marked in the epiphyses of long bones and the margins of flat bones. : During the formation of normal, healthy bone there is always going on an absorption of already formed bone, which, however, remains confined to certain limits. In rickets the extent of this reabsorption is increased, so that in severe cases a large part of the bone may disap- pear. As a result, in the long bones the cortical layer becomes more or less osteoporous, and the columns of bone in the spongy portions become thinner and many of them disappear. This reabsorption of bone is lacunar, and, as in the case of normal bone, is due to the action of osteoclasts. The most striking change is that which occurs in the epiphyseal ends of growing long bones. If one examines a section of the end of a normal long, growing bone (Fig. 647), a straight line may be seen where the white epiphy- seal cartilage is joined to the cancellous shaft. The new bone is formed by a pushing of the medullary tissue from the cancellous bone into the epiphyseal cartilage. The two are joined by a straight, blue, semitranslucent band about 1 mm. broad, that is made up of hyperplastic car- tilage, called the zone of growing cartilage. Microscopical examination shows that in this area the cartilage cells have become greatly increased and are ar- ranged in columns running parallel with the long axis of the bone. After these columns have acquired a certain height, there occurs at their base a deposition of calcare- ous material, which marks the cessation of the growth of cartilage. Ina short time this calcified cartilage is de- stroyed by the pushing upward of the neighboring medul- lary tissue. These “buds” of medullary tissue, consisting of growing blood-vessels surrounded by a thin layer of medullary cells, push up between the columns of cartilage cells, gradually “eating” away the calcified, cartilaginous ground substance. The cartilage cells eventually disap- pear and are probably converted into medullary cells. Thus there are formed primary medullary canals bounded by the remains of the calcified cartilaginous ground sub- stance, and it is this latter which then becomes converted into bone. This is brought about by the deposition with- in this substance of cells from the medullary canal which Fig. 648.—Longitudinal Section of the Line of Ossification in the Femur of a One-Year-Old Child Suffering from Rickets. (After Ziegler.) a, Hyaline cartilage; b, cartilage in the first stage of hyperplasia; c, zone of the columns of cartilage cells; d, columns of enlarged cells; e, vascularized marrow extending into the carti- lage zone; f, calcified cartilage; g, osteoid tissue ; h, remains of car- tilage ; i, columns of osteoid tissues; k, columns of osteoid uncalci- fled tissue, surrounded by true bone; J, vascular marrow tissue. (X 37 diameters.) go to form the osteoblasts. The cartilage has formed the framework on which the growing bone has climbed, and is itself eventually absorbed. In rachitic bone, the blue transition zone of hyper- plastic cartilage is much wider, while its outline, both 121 Bone, Bone, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. above, below, and at the circumference, is enlarged and irregular. It is this which forms the irregular enlarged ends so characteristic of the disease. The zone of hyper- trophied cartilage cells as well as the columnar zone is enormously enlarged. There is also a more or less com- plete absence of the zone of calcification of the cartilag- inous groundwork, and in addition there is a great ir- regularity in the formation of the vascular, medullary Y ris a, os “y 1, %, st se 7 ch agape as yt ice a st / 4 eg KZ 7 Mehe (After Fic. 649.—Necrosis and Inflammatory Hyperplasia of Bone. Boyce.) 1, Spongy new bone; 2, remains of shaft; 3, sequestrum. (Slight enlargement.) canals. These have pushed their way into the cartilage in an irregular manner as though unrestrained by the presence of a firmly calcified groundwork. The persisting columns of cartilage are gradually con- verted into an “osteoid” tissue, made up of cells derived from the medullary tissue and a fibrillar, uncalcified groundwork. This osteoid tissue will show in numerous places islands of persisting cartilage. The zone of os- teoid tissue may attain a length of 15 mm.; it is a firm, elastic connective tissue, but it bends under pressure. It differs from bone in that the cells have not the same regu- larity of arrangement, and in the absence of earthy ma- terial in the groundwork. At a varying distance below this zone we finally come upon a zone in which columns of osteoid tissue are be- coming converted into bone by the calcification of the groundw ork. Inflammations of bone occur in the periosteum, in the marrow, or inthe joints; that is, always in those portions of the bone which’ are well supplied with blood-vessels. They are as a rule due to hematogenous infection or to trauma, although occasionally they may be brought about by extension from neighboring tissue. If the inflamma- tory process is of any considerable degree, or lasts for a considerable time, it is always followed by changes in the bony substance itself. This, asa rule, is of a retrograde character, 7.¢., leading to destruction of bone. If the in- flammation is of a highly infectious, purulent character, the connective tissue affected becomes dissolved, the ves- sels become thrombosed and are destroyed, and the bone becomes necrotic. If the inflammation is less severe in character, if it is accompanied by considerable cell infiltra- tion and the formation of new vessels (granulation tissue), there follows a gradual solution of the neighboring bone or cartilage, an ulceration, or, as it is usually called, caries. As long as this inflammation keeps up, so long is there a gradual absorption of the neighboring bone or cartilage. If in the beginning of the inflammation there occurs necrosis of a certain portion of bone, there follows in the later stages, at the surface of this necrosed portion, a gradual absorption which has its greatest intensity at the 122 border between living and dead bone, so that eventually the two become separated and there is formed a seques- trum. If the latter isnot very large it may in the course of time become completely absorbed by the neighboring granulation tissue. Large sequestra, however, offer a great deal of resistance to this absorptive process and may remain for years. As long as the sequestrum is present so long will the inflammation keep up, even though the infection has been overcome. sve oe seinem 12.59 Magnesium bicarbonate % ....035 2 css sic vies be > entesien eration 3.12 AlUMINUM PHOSPHAL!S ss acta’ ccscssrstelcleisie ie wivieleuelon eimai P Aluminum and dron’ carbonate cic. «- «es sess sleet 64 MANGANESE 5 vo:ciccaie,o cleissesclelois stovereletesnnareceleraie ettaleiniettratstetn annem Trace. BLIGE io sides eSeretes aeeevelore clones ele nloteseserele eleleceiotenietetere atietene Organic matter .'. cccilecs accieveividiodlae eteisniiee casa celts Trace TOCA sera arave a sister elate's ciate’ ccacsi@ielerelete' sieteiate ce stein a aie einen 432.28 Suiphureted hydrogen............s++0 A perceptible quantity. This water is quite a strong muriated, alkaline saline. It is a very efficient antacid laxative, with diuretic and diaphoretic properties. It also derives a certain tonic and restorative influence from the presence of iron, phos- phorus, and manganese. In addition to its table value it has been found to possess excellent therapeutic properties in chronic affections of the stomach, bowels, liver, and kidneys. It acts with great efficacy in renal dropsy. James K. Crook. BOROGLYCERIDE.—Under this title there has been introduced into medicine a compound formed by direct. reaction of boric acid upon hot glycerin. In this reac- tion tribasic boric acid replaces the three hydroxy] equiva- lents of the molecule of glycerin, forming glyceryl borate, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Borie Acid, C;H;BOs, with evolution of water, as per the follow- ing equation: C;H(OH); + HsBO; = C;H.BO; + 3H,0. Boroglyceride is a solid, vitreous body, transparent, and of a light amber color. It has little odor, and a slightly sweetish taste, with a faint astringent twang. hygroscopic, rapidly becoming sticky on exposure to the atmosphere. It dissolves freely in glycerin, and, melted into an equal weight of that fluid, forms a permanent, viscid, clear solution. The solubilities in water and al- cohol have been stated very variously. A sample tested by the writer broke up into opaque, granular flakes by treatment with cold water, but finally dissolved in ten times its weight of that fluid; and in cold absolute alco- hol it dissolved slowly but completely, in even less than its own weight, forming a clear, syrupy solution. Boroglyceride is reported to be strongly antiseptic, and was originally proposed by Barff, before the Society of Arts of London, as an agent for the preservation of food-stuffs. Taken internally it has seemed to be as in- nocent as the two substances of which it is compounded. It has so far been used in medicine locally only, being - applied—generally in glycerin solution—as a dressing to wounds, ulcers, catarrhal mucous membranes, etc. It is claimed to be at once antiseptic, astringent, and healing, while inodorous and practically unirritating. It is most commonly employed in fifty per cent. glycerin solution, or in ointment made by mixing one part of such glycerin solution, while hot, with three parts of vaselin. What amounts to a fifty-per-cent. glycerin solution of boro- glyceride is official in the United States Pharmacopeeia, under the title Glyceritum Boroglycerint, Glycerite of Boroglycerin. In this case the solution is made directly by treating boric acid with hot glycerin in proper propor- tion. The preparation is a colorless, glycerin-like fluid. Asa preservative, boroglyceride has been recommended in solutions ranging from two per cent. to five per cent. in strength. Edward Curtis. BORNEOL.—Borneo Camphor ; Dryobalanops Camphor. (CioH,;,—OH). A camphor-like body occurring in the wood, and in lumps in the cavities thereof, of Dryobala- nops aromatica Gaertn. (fam. Dipterocarpacee), in a number of Coniferw, in valerian, rosemary, and several other aromatic plants. The article is not exactly the same, differing especially in its optical properties, from these different sources. That commonly sold is artifi- cially made from ordinary camphor by the action of so- dium. This differs from ordinary camphor in its much higher melting and boiling points, and in not crystallizing upon the sides of the glass containers. It is crystalline and soluble in alcohol. It is used externally as a disin- fectant to sores. H. H. Rusby. BORRAGINACEA.—A family of some eighty-five gen- era and nearly fifteen hundred species, most widely dis- persed, but mostly in warm temperate climes. Except for ornamental purposes, especially the heliotropes and forget-me-nots, the family is but little utilized. Its chief use at present is to yield the coloring matter alkanna red. Historically, it is of considerable interest in medicine, the borage, comfrey, lungwort, eritrichium, vipers bugloss, and other drugs having formerly enjoyed a high, though ignorant repute. Although some of their alkaloids are quite active, they occur in inconsiderable proportions. H, H, Rusby. BORTHWICK MINERAL SPRINGS.—Also known as the Otfawa Mineral Springs. Post-OFFICE.—Ottawa, Canada. Access.—By carriage drive from Ottawa. Awnatysis.—By I. Baker Edwards. ONE PINT CONTAINS: suiias. Grains. COMIGTICE OL SOGLUIN, vectaticiaceiercers even malcieinateelsclesisiersi tie 6 98.081 OHIOTIAG Ol DOLASSIUTI Ss cicrerseielerecieteYelelovaistsiers ie iclevctarcle's eisteve 1.310 TOTIAS Of CAICLUININ cots tlete's siete alerosib ce sents alcineie eisietelo 8 1.832 Boston. Solids. Grains Chloride: Of MAPNERINMN Feces ceases sles cie ces Seishin cweiae 2.7138 Bromide and iodide of magnesiuM..................05 351 SulpNateOf CALA ois ck clerelaietacle eee aca'estie.cieie a alcle% ofieve 2.019 Sulphate of maonesiuineey cnc. reese: ste secre eels one 2.450 It is Trony stron tlumisant asides delta teteaissslesiste sis'ss caven slvwe's Traces. Total gacktacpiante cecal Aten ie siies sa vicmionnnecatstss 108.756 This is an unusually pure saline water, containing a large percentage of iodine and bromine. A small amount of purgative salts is also present, forming an excellent combination. There is no aération with carbonic acid. These waters are extensively used by the residents of Ottawa and vicinity. Their reputation is steadily in- creasing and their sale has assumed enormous proportions. Beaumont Small. BOSTON.—Massachusetts. Although this and vari- ous other cities which wili be mentioned in the HANDBOOK are not health resorts, yet it frequently happens that an invalid is obliged, from reasons of necessity, to spend more or less time in them, and it isa satisfaction to know some- thing of the climate and weather which may be expected. Further, as Dr. Huntington Richards, the previous editor of this department, says: “ One can better form an opinion of the climate of any health resort he may have under consideration, if he compares it with that of the place in which he resides or with that of some place with which he is familiar.” For these reasons, then, the climatic tables and general weather conditions of the principal cities of the United States will be given. The climate of Boston is characterized by great vari- ability and range, from a possible maximum of 101° F. in July to — 13° F.in January. Theeast winds, although not the prevailing ones, as the climatic table indicates, are still frequent enough to form one of the peculiar characteristics of this climate. They are damp and chilly in winter and early spring, and render outdoor existence exceedingly uncomfortable. “A chill no coat, however stout, Of homespun stuff can quite shut out— A hard, dull bitterness of cold.”’ In the summer, on the contrary, they modify the heat and are very refreshing. Ask any inhabitant what is the one striking climatic peculiarity of Boston, and he will immediately reply, “ The east wind.” CLIMATE OF BOSTON, MASS. LATITUDE, 42° 21’; LONGITUDE, 7194’. PERIOD OF OBSERVATION, FROM 13 TO 25 YEARS. ELEVATION OF PLACE OF OBSERVATION ABOVE SEA LEVEL, EIGHTEEN FEET. Data. Jan. | Mar. | July.| Year. Temperature (Fahrenheit Scale). AVCrage OL DOTMAl «an cncecusieatitos sts 27.0°) 34.2°| 71.3°! 48,.2° AVGYASS GALLY, TANGLE ce vinsnic ceisler vos 17.2 | 16.5 | 17.9 Mean of warmest (average maximum) ..| 35.3 | 42.2 | 80.8 Mean of coldest (average minimum).....| 18.1 | 26.7 | 62.9 Highestior Maximum sees ashe css hoe 70.0 | 72.0 |101.0 HOWeSt OM MINIM UMiget wote ns evivieeetciee © -13.0 |—7.5 | 46.0 Humidity. Mean relative (average) ........sesseee0. 71.8%] 69.4%] 70.8%] 69.6% Wind. Prevailing direciorr. steers es sie esc cris ces N.W.|N.W.| W. WwW. Average hourly velocity in miles......... 14.2) 11.3] 8.5 Weather. Average number of Clear days........++- 8 Soiree LOs TAL P CS eR Be eet on a ade ccraaesicrce's 13 sisithe. 1b, AD Smallest re id ti IRE aa 4 3 Average A fairey) ers ee es 10.6 | 9.5 | 13.7 |184.6 Largest es + ran chbonee cece 15 20 Smallest Si i: Be aisigaanaeire ib 3 Average - CLOUDY sul oweeouts tas 12.4 | 12.5] 9.4 |185 Largest g > Sada nts sas om se 23 Smallest hey os FAS Aavassaricice’ 3 Average number of rainy days, .01*inch ANG OVER. Alu cow cae seine nove Ceswnanee ss 2.2 )138.7 |) 11 {180 Smallest number of rainy days aeeistanetele e6 4 Age 6 Targest eye adie. CPP cod hose naa 18 17 131 Boswell Springs. Bournemouth. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. The cold season begins in November, although it is occasionally mild even to Christmas, and continues until April; snow is for a great part of this time upon the ground, although not always continuously. March, on account of the high cold winds, is one of the most disagreeable months of the year, and June one of the most delightful, although the latter part of the month may be uncomfortably hot. In the summer, the heat, oppressive at times on account of the dampness, is not continuous, and in the writer’s experience, froma climatic point of view, the spring and summer are the best seasons to spend in the city, and January, February and March, the months to be avoided by achange toa milder climate. Fashion, however, has it otherwise. The writer recalls the case of a family whose members had come on from St. Louis, in search of an Eastern seaside resort, but who, on arriving in Boston, had found the place so comfort- able that they decided to remain there the whole summer. The excursions by water are numerous and very de- lightful, and the country around is easily accessible and attractive. Boston is noted for its beautiful suburbs. Edward O. Otis. BOSWELL SPRINGS.—Douglas County, Oregon. Post-OFFIcE.—Boswell. Hotel. AccEess.—Boswell is a flag station on the Southern Pacific Railroad (Shasta Route), 163 miles south of Port- land. The location of the hotel is one hundred feet from the railroad. The situation is on Elk Creek, about 45 miles from the coast and 350 feet above tide water. The surrounding country is made up of hills and valleys. There are two springs at the resort. A partial analysis of the stronger spring, made at the University of California, showed the presence of two thousand grains of solid matter to the United States gal- lon, made up chiefly of the following ingredients: Iron, bromine, potassium, calcium, magnesium, sodium. The weaker spring was analyzed by Philip Harvey, of Portland, Ore., who gave its contents as follows: ONE UNITED STATES GALLON CONTAINS: Solids. ® Grains. Soditim: :CHIOTIAG, Vo aires cielercdios clecels wtatctesle ota as haie senate 173.00 MATES UI CHIOLLGET. cycivaverere oltisiaisleieisialate staisvartve) eleeetcietorayere 145.00 Calcium (CHIOTIAE) er.cta c's onic sivietaiese ss sieiersiniisieieeihs + Dracies 115.00 Tron carbonate { Ta ees [ter te reece eee ee reece eee TOtALS ca ciantast catele aisles aistate ale ature ides ei atate ele etetaietatonaatale 433.00 Small quantities. Both springs are heavily charged with carbonic acid and sulphureted hydrogen gas. The waters are evidently of the muriated-saline-chalybeaté variety. They have been found usefui in constipation, chronic malarial infec- tion, dyspepsia, functional liver complaints, and other disorders. J. K. Crook. BOTHRIOCEPHALUS LATUS. See Cestoda. BOULDER.—Colorado. A town of 4,000 inhabitants, situated at an elevation of 5,800 feet above sea level, in the heart of the Rocky Mountains, 30 miles northwest from Denver. “The town is situated close to the foot- hills near the entrance to the Boulder Cafion” (Solly). The soil is dry and porous, except in areas of clayey soil. The water supply comes from a reservoir on Boulder Creek, five miles above the town, and also from wells, springs, and the creek itself. The hotels are said to be fair (Solly). Although the meteorological data for Boulder itself are very incomplete, so far as the writer has been able to learn, they cannot be very different from those at Denver, thirty miles away (see article on Denver). Solly gives the mean monthly temperature for Boulder, from obser- vations extending over a period of one year and a half, as follows: Winter, 30° F.; spring, 49° F.; summer, 65° F.; autumn is not obtainable. The average number of cloudy days during the winter is 13. 132 Boulder is one of the many representative places in the great high-altitude, health-resort belt of the Rocky Moun- tains, extending from Wyoming south along the eastern base of the Rocky Mountains, through Colorado into New Mexico, and then turning southwest into Arizona. “In this belt no particular spot is materially better than an- other, so far as climatic conditions are concerned ” (Re- port of the Committee on Health Resorts. Transactions of the American Climatological Association, 1895), Boulder, like many other localities in this belt, would seem to offer an almost ideal climate for the high-altitude treatment of phthisis: almost constant ‘sunshine—but thirteen cloudy days on an average during the winter, clear bracing air, low relative humidity, nights that give invigorating sleep and rest, and grand mountain scenery. But it is well to repeat what has been before said, that climate is but one factor, although an exceedingly im- portant one, in the treatment of phthisis, and in order to obtain the greatest advantage from any climate, however ideal, there must be at hand proper hygienic conditions and wise medical supervision. Phthisical patients in health resorts require, as a rule, constant guidance and restraint; they must know when to practise the rest cwre, and when it is safe to take exercise and how much. Edward O. Otis. BOULDER HOT SPRINGS.—Jefferson County, Mon- tana. Post-OFFIcE.—Boulder. Hotel and cottages. These springs are located within two miles of the town of Boulder, about midway between Butte and Helena. They are reached by both the Northern Pacific and the Great Northern Railroad. The springs are numerous, and some of them havea large outflow of water. The surrounding country is of a rugged, mountainous character, the loca- tion of the springs being 4,904 feet above the sea level. The following analysis, supplied by Mr. George B. Beck- with, manager of the springs, was made at the Columbia School of Mines, New York City: ONE UNITED STATES GALLON CONTAINS: Solids. Grains. Sodium CHLOLIGE 6 :..0:<.<.+ olsig:< 9. 0,sth,sve eis cineie: aietec cltreieeee teen 4.70 Sodium sulphate... 6s cic sce pegs sve cle efors siccatelersieleuleoneeteeeaate 4.30 Sodium Carbonate s.:io ii. isc /aisterersteie olae'sce aetna en 2.60 Calcium) CarbOnates..c< ii stsic cleje om sicieteie elelelee ciate Catajereietasiete 1.30 Magnesitim, GarPOnate \a\.c.cs.e0..00% esos sinjes'e cfeleita pletlaeaneeene 3.60 Bul PDULs «2 s.06 a'oe oe wale ce eae. vro ale/alahevescye ete ce. or areldiaec teeta teeta 4.80 TY OM «\5:0:5%5.4's:510:0 oinleleie.e.0(6.0'¢,0 ocer¢) olehe,olelpserecojelere-elelealeraverete aaa ae 2.90 MTOtAL si cec cree clsice scree ovine uel avoielsaveleteiayevere eteltiaa gianna 24.20 The temperature of the springs ranges from 125° to 187° F. The water is said to be very palatable as a beverage. The hotel is heated by the water of the springs, and bathing facilities are abundant. The dis- eases especially benefited here are rheumatism, indiges- tion, chronic constipation, renal, cutaneous, and hepatic diseases, and metallic poisoning. J. EK. Crook. BOURNEMOUTH, England, is a city of 17,000 or more inhabitants, and is situated on the south coast of Eng- land, in Hampshire, 374 miles from Southampton. “It is built ona flat, pine-covered heath which abuts abruptly on the sea in the form of great brown sandy cliffs.” “The East Cliff, the West Cliff, the Valley, and the Coast are the four natural divisions of Bournemouth.” The East Cliff, over a great part of its extent, slopes land- ward and thus has a westerly and southwesterly as well as a southerly aspect; it is the older residential quarter of Bournemouth. The West Cliff is more elevated and exposed than the East, and is the newer part of Bourne- mouth; it contains the larger number of boarding houses. The Valley of the Bourne affords the maximum of natural protection from the wind which the place can claim. The lower part is an attractive public garden, and the eastern slope, which is covered with pines, affords a perfectly sheltered, sunny and quiet promenade and resting place; the well-known “ Invalids’ Walk” is to be found here. The Coast is in the form of rugged high cliffs, bright REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Boswell Springs, Bournemouth, with green and yellow gorse, and broken by deep irregu- lar chines, Pines, much resembling those in our South- ern States, are everywhere to be seen. On the East Cliff Fie. 650.—Invelids’ Welk, they are so abundant, fringing the streetsand level walks and sheltering the houses, “that this portion of the city has been well described as a town in the wood.” The heath all around Bournemouth is aiso covered with pine woods. The aromatic emanations from the pines are sup- posed to impart salubrious properties to the atmosphere. Beneath and about the pine trees the furze, rhododen- dron, and holly flourish in great luxuriance. The sea lies full to the south, and on the eastern horizon are the Needles and Alum Bay, in the Isle of Wight. A pier 838 feet long extends into the sea and has specially constructed shelters for invalids. The soil, consisting of a greenish sand, is highly absorbent and very dry. The principal facts relating to the meteorology of Bournemouth are exhibited in the following table: METEOROLOGICAL MEANS of rain or occasional cold- winds or dust. The town possesses a good drainage system, and the water supply is above suspicion. Cournemouth, England. The general opinion of local practitioners, as expressed broadly, is that “most cases of pulmonary tuberculosis improve at Bournemouth.” At the same time the climate of Bournemouth cannot be represented as equal to the best of the foreign climates, such as the Riviera or the Alpine stations. Dr. C. Theodore Williams’ results are: “Twenty patients, each one winter at Bournemouth; six much improved, seven improved, two stationary, and five worse.” The special features of Bournemouth as a health resort, as summarized by the report of acommittee of the Royal Medical and Chirurgical Society of London, 1895, to which the writer is indebted for the above account, are as follows: “Bournemouth is distinguished by the general beauty FOR TEN YEARS, 1881-1890. Jan. Feb. | Mar. | April. |. May. | June. | July. | Aug. | Sept. | Oct. Noy. | Dec. | Year. Mean temperature (Fahrenheit) at 9 a.m ...| 40.30° | 40.70° | 42.80° | 49.80° | 56.10° | 61.50° | 64.80° | 63.60° | 58.80° | 51.00° | 4¢.30°) 41.00° | 51.40° Mean minimum temperature ..........0000+ 34.40 | 34.50 | 34.90 | 38.50 | 44.60 | 50.80 | 54.20 | 52.60 | 49.70 | 42.90 | 39.80 | 34.60 | 42.60 Mean maximum temperature ...........05- 44.70 | 45.80 | 48.50 | 44.90 | 62.00 | 68.20 | 71.00 | 70.90 | 65.80 | 56.30 | 51.00 | 45.00 57.10 Mean relative humidity ............. Sion 85.00 | 89.00 | 80.00 | 68.00 | 69.00 | 69.00 | 69.00 | 70.00 | 81.00 | 81.00 | 87.00 | 85.00 77.70 Ai GHtE POULEIT AUN aries ole cc's: 'ee.e beaten Waiters CL: 1.85 1.83 | 1.61 2.18 1.17 2.07 1.84 2.46 3.14 3.36 2.53 | 27.26 Mean number of rainy days........ Sis prater elas 14.80 | 10.50 | 11.50 8.70 | 10.80 | 11.30 | 14.80 | 15.00 | 11.50 | 18.80 | 17.20 | 14.70 | 158.30 From the above we see that the mean temperature for the whole year is 49.7° F., or, at 9 a.m., 61.4° F. The mean minimum temperature is 42.6° F. and the mean maximum 57.1° F. The mean relative humidity at 9 A.M. is 77.7, the lowest recorded in England. The mean total rainfall is 27.26 inches, and the mean number of rainy days 158.3. Onan average it has been estimated that there are about two days a week during the winter season when patients cannot go out safely in consequence of its position, which combines the attractions as well as the wholesome influences of sea and heath. Asa whole, compared with England, it possesses a mild, bright, and fairly dry climate. The atmosphere is naturally pure, sunny, free from fog, redolent of the pine, of low relative humidity, and comparatively undisturbed by high or cold winds. The soil is dry and warm, permitting patients to sit with comparative safety in the open air; and it sup- ports an abundant and luxuriant growth of non-decidu- 133 Bowden Lithia Box. {Springs. ous trees and shrubs. The town area is very large in re- lation to the number of houses and inhabitants.” On the other hand, “like other places on the south coast, it is subject to frequent and uncertain spells of bad weather, in the form of wet, cold, or both combined, and to even more dangerous, because deceptive, visitations of high east winds in the early spring.” “The kinds of cases which have been benefited by a residence at Bournemouth are chiefly as follows: “(1) Cases of pulmonary tuberculosis which would do well at any good health resort. (2) Pulmonary tubercu- losis in the incipient stage. (8) Quiescent pulmonary tuberculosis when the patient can spend a number of hours continuously in the open air. (4) Patients in the last stage of phthisis often enjoy an extension of life here. In general, cases that can take advantage of out- door life do well, while those who are confined to the house do badly. (5) Chronic bronchitis without fever, and particularly recurrent bronchial catarrh with a mod- erate amount of expectoration, asthma, whether neurotic or catarrhal, the different parts of the town being tried if necessary. (6) Chronic Bright’s disease, particularly of inflammatory origin. (7) The subjects of chronic ma- laria. (8) Sufferers from chronic gastric catarrh with emaciation. (9) The victims of nervous over-work, particularly with insomnia, provided they do not settle too close to the sea. (10) Delicate persons generally, in- cluding more especially elderly and aged people, and feeble and rickety children.” “The cases, on the other hand, which do not do well or even badly, are: (1) Persons confined to the house, applying chiefly to consumptives. (2) The subjects of pulmonary tuberculosis in its active stage, especially when attended with much fever and profuse expectora- tion. (8) Those suffering with dry irritable catarrh of the larynx and bronchi. (4) Sufferers from neuralgia.” The accommodations are good and abundant and of every variety. From a personal visit the writer was im- pressed with the beauty of the place, its clear, bright atmosphere, the abundant sunshine, its luxuriant vegeta- tion, and the striking effect of the great number of pines everywhere. The sea view from the cliffs is most attrac- tive, and there are many pleasing excursions inland over the thickly wooded heath. For an outdoor life one can hardly imagine a more attractive place of residence. Edward O. Otis. BOWDEN LITHIA SPRINGS.—Douglas County, Geor- ia. 2 Post-OFFIcE.—Lithia Springs. tel. Accrss.—Via Georgia Pacific Division of the Piedmont Air-Line. These springs are located in Douglas County, 17 miles west of Atlanta, 300 miles distant from the Atlantic coast and at an altitude of 1,200 feet above the sea level. The surrounding country is of a some- what rugged, broken character, interspersed with forests of pine, oak, maple, and cypress and watered by streams skirted by haw and holly. The temperature rarely reaches 90° F. in summer or extends below 40° above zero in winter, while the nights are proverbially pleas- ant. The surroundings of the place are exceptionally charming, the Shoals, the Ruined Mill, Chapel Hill, and the Dome Rock, showing the mighty action of some great sea in prehistoric times, the Mill in the Glen, the Old Distillery, and the Sweetwater Creek being also among the numerous features of interest. The hotel is a first- class modern structure, capable of accommodating five hundred guests, and all of the appointments are of a superior order. While people have resorted to these springs for about sixty years, only recently have they become very extensively known. The use of the Bowden lithia waters is particularly recommended in kidney and bladder affections, calculi, gravel, cystitis, etc., and in gout and rheumatism. The external use of the water in bathing, for which there are excellent facilities, is said to be beneficial in skin affec- tions, chronic ulcers, glandular enlargements, etc. The Sweetwater Park Ho- 134 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. waters are used commercially, and may be found in most of the principal cities of the East and South. Following are analyses of the waters: ONE UNITED STATES GALLON CONTAINS: arabe ets X pring. pring.) | Dorem Solids. Pratt, Pratt, 1890. 1887. 1889, Grains. | Grains. | Grains. Carbonic acid as bicarbonates........ 9.85 WW sataeee 9.91 Lithium bicarbonate ........secsseees 2.85 1.67 4.45 POtAsSl UM DOM Cee ace are cial tale ate) ohare leel] Mmreroletsiee B28: Wi Mementte Potassium SUIPNHAte...c cece cesciacec ceil) sjeesice lumen 1.73 Potassium HicarboNater: «..). 010+ icesve0e 3.86. || ocean arene Magnesium bromide ..........s..2.+. 1.69 15.23 1.47 Magnesium bicarbonate.............. 10.82)" LL a aaa naan nnn nn nan en eee VIII. The Rhinencephal (olfactory bulbs, etc.), §§ 357-372. IX. The Meninges (dura, arachnoid, pia), §§ 373-409. X. Bibliography. § 3. Method.—The text consists largely of commen- taries upon the points illustrated by the figures. What seem to me the more important facts and fundamental ideas of encephalic morphology are embodied in concise propositions. Unless otherwise stated these propositions apply to the human brain, and may not always hold good for those of other vertebrates, or even other members of the mammalian class.* § 4. Mig. 663 illustrates: A. The general aspect of a brain from the side; its continuity with the myel (spinal cord) through the oblongata; the existence of a smaller mass (the cerebellum) and a larger (the cerebrum); the overlapping of the former by the latter more extensive at birth, and in earlier than adult brains; the existence of other parts, the olfactory bulb, the pons, and the oliva (the elliptical elevation of the postoblongata upon which the line from that word ends); the fissures of the cere- ‘brum; the subdivisions of the cerebellum (foliums) are not indicated. (The remaining points illustrated refer to the cerebral fissures, and may be considered more advantageously in connection with Part VII.) B. The simple, almost schematic, relations of the fissures demarcating the several operculums (compare Fig. 784); the preoperculum only is named. The sub- operculum is the region ventrad of the subsylvian fissure. The operculum is between the presylvian and Sylvian fissures; and the postoperculum is the overlapping margin of the temporal lobe, the region on which is the word Sylvian and ventrad of it. C. Theincomplete covering of the insula (see Fig. 788) D. The presence of a distinct medifrontal fissure, sub- dividing the medifrontal gyre. E. The independence of the postcentral, parietal, and paroccipital fissures. F. The presence of the exoccipital (the “ape fissure ” of some writers). G. The frequency of the zygal or H-shaped form of fissure—e.g., paroccipital, parietal, postcentral, sub- frontal, orbital, and fissure 2; see § 307. § 5. The Facts.—Most of the statements are parts of common anatomical knowledge, and special references are seldom given in this connection; therefore the fol- lowing extract from the preface to Huxley’s “ Anatomy of Vertebrated Animals” may be appropriately added: “The reader, while he is justly entitled to hold me re- sponsible for any errors he may detect, will do well to give meno credit for what may seem original, unless his knowledge is sufficient to render him a competent judge on that head.” § 6. The Ideas.—Unfortunately, the facts of anatomy are susceptible of various interpretations according to the relative weight assigned to them. In particular there are divergent views respecting the segmental con- stitution of the entire brain and the normal pattern of the cerebral fissures. § 7. The Illustrations.—Of the one hundred and forty- five figures, one hundred represent preparations made by me for the museum of Cornell University; these reparations are designated by their catalogue numbers, he drawings have been executed, from the specimens and from photographs, by Prof. E. C. Cleaves (C.), Mrs. S. H. Gage (G. or 8. P. G.), and Mrs. Wilder. The twenty-five borrowed figures are credited to their sources. The remaining illustrations are original dia- grams or drawings, or direct reproductions of photo- graphs. § 8. Terminology.—The general subject will be dis- cussed in the article Terminology, Anatomical, in another volume; meantime those interested are referred to the article under that title in Vol. VIII., of the first edi- * The uses of certain animal brains as aids in the study of the hu- man organ are set forth in the article, Brain: Methods, etc., and in my paper, 1896, g. tion, pp. 515-587; to “ Anatomical Technology ” (Wilder and Gage, 1882); to the Reports, during the last ten years, of Committees of the American Association for the Ad- vancement of Science, the American Neurological Asso- ciation, the Association of American Anatomists, and the Anatomische Gesellschaft; to the article, “Anatomical Nomenclature,” by F. H. Gerrish, in “ Progressive Medi- cine,” for 1899, pp. 327-346; to G. M. Gould’s “Sugges- tions to Medical Writers,” 1900, chap. iv.; and to my _address, “Some Misapprehensions as to the Simplified Nomenclature,” Assn. Amer. Anat., Proceedings, 1898, pp. 15-389, and Sezence, April 21st, 1899. The principal publications prior to 1896 are included in the bibliography of my “ Neural Terms, International and National,” Jour. Comp. Neurology, December, 1896, vol. vi. Here, there- fore, it is necessary only to comment briefly upon the two groups of terms employed in this article. § 9. Terms of Position and Direction (Toponyms).—In place of the more or less ambiguous terms wpper, lower, anterior, posterior, inner, outer, etc., will be employed terms referring to the regions of the vertebrate body in whatever attitude it may be—viz., dorsal, ventral, cepha- lic, caudal, mesal, lateral, ental, ectal, etc., constituting an intrinsic toponymy. The adverbial forms are dorsad, mesad, ectad, etc. § 10. Terms of Designation (Organonyms).—Each part is designated uniformly by one and the same name. Where two or more names are already in use, the simpler or shorter has been chosen. In some cases simple names have been formed by the omission of unessential words or by the combination of two, or by the coinage of words from the Latin or Greek. Where the English form (paro- nym) differs from the elassical the former is often pre- ferred. For examples, “ pneumogastric ” becomes vagus ,; “pons Varolii,” pons; “corpus callosum,” callosum ; “commissura anterior,” precommissure; “aqueeductus Sylvii” and “iter a tertio ad quartum ventriculum” give place to mesocelia (the cavity of the mesencephal), Eng. mesocele.* § 11. Mig. 664 illustrates: A. The general form and appearance of the cerebrum of an educated and moral distinguished man, rapid in thought and movement. B. The general symmetry as to form and especially as to certain fissures, central, occipital, paroccipital, in- flected, associated with some decidedly asymmetric con- ditions—e.g., the relations of the postcentrals to the para- centrals. C. The bifurcation of the dorsal end of both central fissures and the bifurcation of the caudal branch on each side. D. The coexistence of the more common relation of the paracentral to the postcentral on the right with the inclusion, on the left, of both branches of the postcentral within the curve of the paracentral; see § 285 and Fig. 769. E. The great depth of both occipital fissures; this is their real depth, and is not due to a superficial extension. F. The distinctness and simplicity of the paroccipital fissures, and the existence of the more usual combination —i.é., continuity with the parietal on the left and inde- pendence on the right: see Fig. 778, G. Nevertheless, the difficulty of deciding how this case should be entered upon a Table. On the right the isthmus between the parietal and the paroccipital is per- fectly distinct and visible in any direct view; yet it is below the level of the adjacent gyres and might perhaps be regarded as a vadum. On the left the vadum (at the point marked 13) is much more depressed, and hidden from easy view by the overlapping gyre just cephalad Ollie H. The unusual complexity of the fissures represent- ing the parietal and the postcentral. On each side there are recognizable three irregular fissures caudad of the central; the most dorsal of each group is triradiate and * Orthographic discrepancies between this article and my recent papers (e.g., in the retention of certain diphthongs and of the ultima of anatomical, morphological, etc.) are due to the necessity of con- forming to the plan of the entire work. 137 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. perfectly distinct, and is marked postcentral ; on the right one of the rays (4) cuts the margin of the hemi- cerebrum deeply. The most ventral (2 and 9) joins the superfrontal (?) inflected (?) 8 central 10 postcentral paracentral parietal 15 paroccipital occipital Fic. 664.—Dorsum of the Cerebrum of James Edward Oliver, Professor of Mathematics in Cornell Il. GENERAL CONSTITUTION OF THE Brarn.—§ 14. Definition.—The brain (Gr., &yxépadoc; Lat., cerebrum ; late Lat., encephaton ; It., cervello, cerebro ; Sp., cérebro ; Fr., cerveau ; Ger., Gehirn; Eng., encephalon, encephal) is the enlarged, segmented, ce- phalic (“anterior”) portion of the neuron or cerebro-spinal axis. § 15. The neuron* is that one of the great mesal (me- dian) organs which is nearest the dorsal surface of the body, and farthest from the heart (Fig. 665). The other two are the enteron (alimentary canal), and the axon (skeletal or body axis; notochord in early em- bryos, but in later stages and adults the series of centrums or bodies of the vertebree), Fig. 670, odontoid process, etc. The enteron is in the ventral (he- mal) cavity; the neuron oc- cupies the dorsal (neural or cerebro-spinal) cavity; the ax- on forms a partition between the two. § 16. Fug. 665 illustrates: A. The existence, in man as in other vertebrates, of two par- allel body cavities, a dorsal or neural, and a ventral or hemal, separated by the axon, the skeletal axis. B. The presence, in the ven- postcentral parietal paracentral occipital University ; aged sixty-six; 3,334. %.57. When removed the brain was firm in texture and weighed (with the piarachnoid but without the dura) 1,416 gm. (49.94 ounces), approximately 50 ounces. It was transected at the mesencephal; the cerebrum was medisected and each half hardened while resting in a mixture of alcohol, formal, zine chloride and water, of specific gravity equal to that of the brain; later it was transferred to increasing strengths of alcohol. The cere- brum is believed to retain very nearly its natural form. The diacele (“third ventricle”) was unusually wide and the medicommissure wholly absent (see §152). There were no obvious signs of diseased conditions beyond a slight opacity of the piarachnoid about the dorsal ends of both central fissures. Professor Oliver was a man of the purest character and a philosophic thinker, in not only the higher mathematics, but other sciences and ethics. He was left-handed and absent-minded, but rapid in thought and action. For an account of his life and a list of his writings, see the memoir by G. W. Hill, read before the National Academy of Sciences, April, 1896; also Science, April, 1895, and the Ithaca Jowrnal, March 28th, 1895. 1 (right) and 8 (left), fissures parallel with the centrals and representing, perhaps, both precentrals and supercentrals; they unite with the longitudinal fissures (superfrontals 7); but a vadum exists on each side; 2 (right) and 9 (left), the most ventral of the postcentral groups; 3 and 10, the middle of each group (sub- central ?); 4, a ray of the postcentral cutting the margin of the precuneus; 5, the right paroc- cipital isthmus; 6, an incision; 7, a distinct diagonal fissure; 8, see 1; 9, see 2; 10, see 3; 12, a fissure cutting the margin of the precuneus deeply but connected with neither the paracentral nor the postcentral; 18, location of the paroccipital vadum. Inadvertently no guide lines indicate the parietal fissures, but they may be recognized from their relations to the paroccipitals. See § 11. tral cavity, of the heart, a hol- low muscular organ, rhythmi- cally contractile during life. C. The presence, in the ven- tral cavity, of a muscular tube, the enteron (alimentary canal). D. The presence, in the dor- sal cavity, of a subcylindrical rod, the neuron (cerebro-spinal axis), itself containing a cav- ity, the neurocele (“central canal” and “ ventricles ”). § 17. Excepting at its first formation (when it is a rod with a dorsal furrow) the en- tire neuron is a tube, a sub- Sylvian fissure. The middle one (3 and 10) is continuous with the parietal on the right, but on the left a vadum may be recognized. I. The unusual location, depth, and symmetry of the inflected (7?) fissures. § 12. References.—In the Bibliography at the close of this article the names of authors and editors are arranged alphabetically. The date after the name is the year of publication, and the following letter, if there is one, designates a particular paper or book out of two or more published within a single year. My own name is abbre- viated in the text to W. My papers on the structure and nomenclature of the brain prior to 1897 are enumerated in the Bibliography of “ Neural Terms,” 1896, 2, which is probably accessible to most anatomists either as a reprint or in the Journal of Comparative Neurology. § 13. Acknowledgments.—For assistance in the making of preparations or photographs, for suggestions as to methods, for helpful criticism of the former edition, or for the loan of figures, Iam indebted to the following former students, of whom several are present colleagues: P. A. Fish, 8. H. Gage, Mrs. Gage, G. S. Hopkins, O. D. Humphrey, B. F. Kingsbury, W. C. Krauss, B. D. Myers, and B. B. Stroud. 138 cylindrical mass enclosing a cavity. This cavity is the newrocele, and the enclosing material constitutes the celian parietes. The existence of the neurocele may be demonstrated by the transection * Certain points relating to this word will be discussed in the article Terminology, Anatomical. The following brief statement is the ab- stract of my paper, 1899, d, as printed in Science, March 16th, 1900, 420: “Is neuron available as a designation of the central nervous system? Newron (from ro vevpov) was proposed by me in this sense in 1884 (V. Y. Med. Journ., August 2d, p. 114), and employed in the same journal, March 28th, 1885, p. 356; in addresses before the Amer. Neurol. Assn. (Jowrn. Nerv. and Ment. Dis., July, 1885) ; Amer. Assn. Ady. Sci. Proceedings, 1885, and in the second edition of * Anatomical Technology,’ 1886. It has been employed by McClure, Minot, Waters, and others. The reasons for its abandonment in 1889 for neuravis, as stated in the Proceedings of the Assn. Amer. Anat- omists for 1895, p. 44, and REF. HANDBOOK OF MED. SCI., ix., 100, now seem to me inadequate. Vewron is the basis of newral (as ap- plied to aspect, folds, furrow, and canal) and of newrenteric and other compounds. and it is the natural correlative of enteron (entire alimentary canal) and of axon (notochord or primitive skeletal axis). Not until 1891 did Waldeyer propose newron for the nerve cell and its processes; not until 1893 did Shafer apply it to the axis-cylinder process. As with tarsus and ciliwm, the context would commonly avert confusion between the macroscopic and microscopic significa- tions of the word ina given case. The compounds macroneuron and microneuron might be employed if necessary, or (as suggested by Barker, 1899, p. 40), the histologic element might be designated by neurdne, as if from vevpsv, The question is now further complicated by Van Gehuchten’s adoption of Neurdve as the title of a new jour- nal of neurology.” REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, of any part of the neuron in any other vertebrate, and in an immature human being; but with the adult, in certain regions, the olfactory bulbs (Fig. 672) and most of the myel (spinal cord, Fig. 670), the cavity is more or less completely obliterated. § 18. Location.—The brain is contained mainly within the cranium, although part of the postoblongata or even, neuraxis esophagus | lieurocele 2 axon lung ¥Fia. 665.—Caudal Aspect of a Thoracic Transection of a Fetus About 3.9 em. from Nates to Bregma, and Estimated at Ten Weeks ; 2,189. x 4. 1, Thorax, part of the ventral or hemal cavity; 2, spinal canal, part of the dorsal or neural cavity ; 3, scapula. Defects.—The fetus was badly shrunken by immersion in too strong alcohol, and the parts here shown dried somewhat while photographing. Certain details as to the pleura, spinal nerves, and arachnoid are omitted, the object of the figure being mainly dia- grammatic. See § 16. as appears in Fig. 670, a little of the cerebellum, may ex- tend beyond the limits of the foramen magnum. Itis remarkably sheltered and clothed by the cranial bones and by the soft parts ectad and entad of them, the scalp and the meninges (dura, arachnoid, and pia) (Figs. 795, 796, 798). § 19. The Brain a Modified Tube.—In its simplest ex- pression the brain, like the remainder of the neuron, may be represented as a tube of nervous tissue lined by a non- vascular, ciliated* epithelium, the endyma(“ependyma”), and covered by a vascular membrane, the pia (“pia mater”). | 20. In what may be regarded as an approximately typical condition, the parietes consist of three layers or strata, viz., an ental, mainly cellular, adjoining the endyma, the entocinerea (“central tubular gray”); an ectal, mainly cellular, adjoining the pia, the ectocinerea (cortex); an intermediate, fibrous, between the other two, the alba or medulla; see Fig. 666. In some regions, particularly the epicelian and paracelian roofs, the ento- ‘cinerea is dislocated or crowded as it were from its nor- mal position next the endyma by albal or fibrous intru- sions, commissures, especially the callosum, Parts of the ectocinerea (e.g., claustrum and lenticula, Fig. 781) are also separated more or less completely from the rest. § 21. Unequal Thickness of the Parietes.—In the earliest * There is considerable divergence of statement among authors as to the presence of cilia, especially in adults. P. A. Fish has described (1890, 256) the ciliated cells in the encephalic cavities of the cat, both oldand young. Heurges the importance of thorough preservation by the injection of the preservative into the cavities ; states that a magnifi- cation of not less than six hundred diameters must be employed, and intimates that the failure to recognize them in man may be due to de- fective methods of preparation or examination. See also the recent aper of Studnitka: ‘* Ueber das Ependym des Centralnervensystems Wirbeltiere.” Siteungsber. K. Bohm. Ges. Wiss., Math. Nat. Cl., 1899, xlv., p. 7. stages the celian parietes are of approximately equal thickness throughout, although certain portions of the roof, ¢.g., of the metacele, are never so thick as portions of the floor. With some low or generalized vertebrates —e.g., Scymnus, a shark (T. J. Parker); Necturus, a sala- mander (W., 1884, a, Fig. 16); Ceratodus, a Dipnoan (W., 1887, a)—this condition prevails throughout life, at least with certain regions. With man, until the fetus attains a length of at least 6 cm., and an estimated age of twelve weeks (see Fig. 667), the cerebral parietes are almost uniformly thin; when 24 cm. long, and about twenty weeks old, certain regions are considerably thicker than others, as seen in Fig. 716; in the adult brain of man, and indeed of mammals gen- erally (Figs. 686 and 735), the difference between even closely adjacent portions of the parietes is simply enor- mous; compare, e.g., the mesencephalic floor (crura) with the caudal part of its roof, valvula (Figs. 670 and 687); the two divisions of the epicelian roof, cerebellum and lingula (Figs. 670, 687, 702); the diacelian sides, thalami, with the floor, tuber or terma (Figs. 670 and 687); the thin or membranous parts (fimbria, tenia, pala, etc.) adjoin- ing the rima with the adjoining hippocamp and caudatum (Figs. 716 and 732). § 22. Telas.—Where the proper nervous constituent of the parietes is wanting the endyma and the pia are in contact and constitute a membranous area or zone, a tela. Among vertebrates the most constant and extensive of these is the roof of the metacele, the caudal portion of the “fourth ventricle,” here called metatela (Figs. 675, 680, 686). A similar portion of the roof of the “third ventricle ” is the diatela (Figs. 675, 681, 682); its cephalic continua- tion as the roof of the aula is the autatela; finally, in man and apes, a part of the floor of the paracele (“lat- eral ventricle”) is a membranous zone, the paratela (Figs. 738, 735). § 28. Hig. 667 illustrates: A.—The large size of the paracele, the thinness of the parietes and their nearly uniform thickness. B. The extent of the paraplexus, and its fulness as compared with that in the adult. Possibly when fresh it CAVITY, CELE, OR VENTRICLE Fic. 666.—Schematiec Transection of the Brain, representing the topographical relations of the two kinds of nervous substance, the white, which is fibrous and conducting, and the gray, which is cel- lular as well as fibrous, and dynamic in function. The entocinerea is primary, and alone exists in the myel; the ectocinerea is second- ary; it constitutes the mesencephalic cappa, and the cortex of the cerebrum and cerebellum. ‘The cilia are omitted. more nearly filled the paracele, but was contracted by the alcohol (compare Figs. 716 and 735). C. The similarity of the precornu and medicornu. D. The absence of distinct indication of the postcornu, indicating that this may be formed eventually not by a special protrusion caudad, but by the thickening of the 139 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. parietes in such a way as to leave an occipital space of variable size. E. The commencing formation of the hippocamp as a corrugation of the mesal wall of the medicornu. paraplexus, Sylvian fossa 2 hippocamp Fig. 667.—The Left Hemicerebrum of a Fetus (Measuring 6 cm. from Bregma to Heel, and Estimated at Twelve Weeks), Opened from the Lateral Aspect; 340. x 3. 1, A fissure; 2, tip of temporal lobe. F. The non-extension of the paraplexus and thus of the rima to the extremity of the medicornu. G. The presence of at least one distinct transitory fis- sure (1). H. The evidences of some mesal fissures as slight corrugations just cephalad of the plexus. I. The formation of the Sylvian fossa, with as yet no trace of the insula. § 24. Pleruses.—As already stated the endyma is non- vascular; but provision is made for the practical intro- duction of blood-vessels into the encephalic cavities by = (Orn ix Y_. pia thalamus endyma portiplexus -porta r__thalamus -— porta ~ portiplexus D Fic. 668.—Schematic Representations of Four Stages in the Formation of the Portiplexus, as a Type of Plexuses. At A. the porta is seen to have the following boundaries: cephalad, the fornix; caudad, the thalamus: ventrad, the junction of the two; dorsad, however, there is merely the endyma passing from fornix to thalamus, and the ectal pial fold, one of its laminz being fornical and the other thal- amic. The first step in the formation of any entocelian plexus is represented at B, where the pial fold (or vessels therefrom) pushes the endyma before it into the cavity. At C the process is carried a step farther, and at D the parts are represented as in the adult, with the plexus apparently inside the porta, and yet really excluded from the cavity by the unbroken covering of endyma. the formation of plexuses at various points. A plexus igs an apparent intrusion of a fold of pia, or of vessels from the pia, into one of the cavities; but the endyma is carried before the intruded portion, and covers it com- pletely so that, strictly speaking, neither the pia nor its vessels are in thecavity. The conditions are comparable 140 with the relations of the abdominal viscera to the peri- toneum. If one takes a closed sack of flexible material and pushes the fist against one side it may be carried so far as apparently to be within the sack; yet all the while it is covered by the material of the sack and strictly excluded from the true cavity. Simple examples of the plexus formation are presented by the epiplexus (Fig. 695), and portiplexus (Fig. 668). The metaplexus is seen in Fig. 686; the diaplexus in Figs. 686 and 782; and the paraplexus in Figs. 718, 726, and 732. The dispropor- — tionate size of the paraplexus at early stages (Figs. 667 and 747) indicates that it is intimately related to the growth of the cerebrum. The structure and diseases of the paraplexuses are discussed by Findlay, 1889. § 25. Ripa.—Where the endyma leaves the nervous parietes either at the margin of a tela or for reflexion upon a plexus, there is a sort of shore line which I have calledripa. The name was originally given to the ragged edge left when a tela or plexus is torn from the nervous parietes (see Figs. 692, 699). § 26. Fig. 669 tllustrates: A. The effect of the cranial flexure (§ 36), the two segments, mesencephal and epen- cephal, with their cavities, appear- ing upon the same section surface, B. The _ triplic- ity of the epicele, consisting as it does of a mesal portion and two lateral extensions, the lateral recesses (§ 60). In Fig. 695 the lower part of the figure is still more enlarged, and commented mesocele ~_ epicele < lateral recess . * cerebellum __ preoblongata -—___\__. upon. 9 ayjiy, FIG. 669.—Transection of the Brain of an Em. § 27. Lhe Brain bryo Rabbit, Sixteen Days Old. X 9. (From as @ House.— Kialiker.) Within certain limits the brain may be likened to an edifice, and the comparison has been carried out in some detail on p. 413 of Wilder and Gage, 1882. Architectural terms, floor, roof, sides, may be employed appropriately to in- dicate the general locations of the parts relatively to each other and to the common cavity, and I have proposed two specific terms, aula (a hall) and porta (a doorway), for the designation of certain portions of the cavity. § 28. Irregularities of Contour.—In the brain straight lines and plane surfaces are infrequent, and the spiral form is not uncommon; hence dissections are often more instructive than mechanical sections, and normalization, actual or ideal (§ 38), is sometimes desirable. § 29. Commissures, ete.—Of the parts connecting lateral masses across the meson, whether cellular or fibrous, whether direct (true commissures) or oblique (decussa- tions), some are merely specializations of pre-existing floors or roofs; ¢ég., precommissure, postcommissure, supracommissure, pons; others, the callosum and com- missure of the fornix, are marked extensions of pre- existing lines or areas of conjunction (Fig. 741). The medicommissure, finally, as well remarked by Spitzka, is rather a fusion of contiguous surfaces than a com- missure in the usual sense of the word. § 380. Atrophic Parts.—Certain parts (terma, hemi- septum, valvula, tuber) which are very thin and ap- parently functionless, nevertheless serve to contain the neurolymph (cerebrospinal liquid), and may have a morphological significance as representing parts more developed in other forms. ‘Two other parts, the epiphy- sis (“pineal body”) and the hypophysis (“pituitary body ”) are rather thick than thin, but are not known to have definite functions; their peculiarities will be con- sidered in connection with the diencephal (§§ 146, 154), of which they are appendages. § 31. Riparian Parts.—Along the ripas, or lines of re- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ae ert Brain. a flection of the endyma upon telas or plexuses, the sub- | metacele (Fi 2); i i C I 2 oe 3 g. 702); the fimbria along the hippocampal stantial nervous parietes are commonly reduced in thick- margin of the rima, the tenia along ie aE At iepint ness, so as to resemble the terma, valvula, and tuber in | and the pala at its extremity (Figs. 730, 732, and 735). some degree. Such are the obex at the end of the § 32. The riparian condition may not be incompatible on ids OR EE tas coronal suture: ere Dae ei lambdoidal suture myelocele { Teceae Nae ae PNIO Xana - Fig. 670.—Mesal Aspect of the Right Half of an Adult Head, the brain hardened in place by continuous alinjection; 811. X .7. (This was the head of William Menken, who was hanged for murder in July, 1885; the specimen was shown at the American Neurological Association in 1886, and at the American Laryngological Association in 1888 [see article by Dr. Harrison Allen, in New York Medical Journal, February 2, 1889] ; the mode of preparation is described in the article Brain : Methods, etc.). 1, The star upon the mouth of a vein opening into the longitudinal sinus indicates the location of the dorsal end of the central fissure ; 2, caudal part of the paracentral fissure ; 3, inflected fissure ; 4, supercallosal fissure; 5, callosal margin of the falx, indicated by the interrupted line; 6, occipital fissure; 7, calcarine fissure: 8, in the longitudinal sinus just dorsad of the torcular; 9, tentorial sinus; 10, a sphenoidal sinus (not vascular, but a cavity in the sphenoid bone) ; 11, a frontal sinus; 12, naso-palatine canal; 13, basioccipital bone; the basisphenoid has 10 upon it, but the two bones are continuous: 14, naso-pharynx ; 15, oro-pharynx; 16, soft palate. The heavy black line bounding the shaded mesal cavities is the endyma. Defects.—The planes of section of the brain and of the other parts are not absolutely identical, although perhaps nearly enough so for most purposes. Many of the boundary lines are too faintly indicated, e.g., that of the section of the chiasma. A continuous line represent- ing the pia should have surrounded all the cut surfaces in close contact therewith. Another line representing the arachnoid should follow the general contours, as stated more fully in connection with Fig. 801. The segmental name diencephal, hides most of the oval area indicat- ing the medicommissure; this last should have been named and should not be dotted. The heavy black line representing the endyma should extend farther into the stem (infundibulum) of the hypophysis, and into the epiphysis, as in Fig. 687. At the second e of the abbreviation MESEN the endymal line should not be interrupted. The interruption opposite the n of the abbreviation METEN represents the metapore (foramen of Magendie), and should have been so designated as in Fig. 687. Notwithstanding the minuteness of the myelocele (‘central canal of the cord” ) in the human adult its location should have been indicated by the continuation of the endymal line. The neck, scalp, features, and all the soft, vascular parts are swollen by the alinjection; the margins of the tongue are moulded upon the teeth; the soft palate and dorsal wall of the pharynx are obviously thickened, and the subturbinal projects beyond the true margin of the septum into the naso-pharynx, as is perhaps the case temporarily during the congestion attending a severe “cold in the head.” No attempt has been made to indicate the blood-vessels, the structure of the skin, the exact direction of the lingual muscles, or the details of the nuchal region. 141 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. with distinct and even important functions. The supra- commissure and the habena (Fig. 707), for example, are, in one sense, parts of transition from substantial to mem- branous parietes; but they doubtless, like the fimbria, have some distinct use. § 83. Marginal Cinerea.—The riparian parts mentioned in § 31 consist of alba; but with the cerebrum and cere- bellum the cortical margins have a special morphological interest, and are but little known. § 84. Physiologically the intermediate portions of organs are commonly most important, as well as most easily recognized and examined; but morphologically the extremes have great significance, and present un- solved problems for future investigators. § 35. Fig. 670 illustrates: A. The relative location and extent of the cranial and facial regions of the head so far as they appear at the meson. B. The continuity of the two portions of the neuron, the myel (“spinal cord”), and the brain (encephal), at or near the junction of the cranium with the spine. C. The obvious subdivision of the brain into several regions, represented, for example, by the cerebellum, the cerebrum, and the intervening narrower part, which is sometimes called isthmus cerebrt. D. The possibility of recognizing in the adult brain smaller divisions or definitive segments, corresponding with the divisions of more nearly equal size in certain other vertebrates. E. The difficulty of assigning exact lim- its to the brain and myel or to the regions of the brain, since they are continuous and do not present arthra (articulations or joints) as with the skeletal segments. F. The representation of each segment at or near the meson by some well-known part: the metencephal by the postoblon- gata; the epencephal by the cerebellum and pons; the mesencephal by the crura and geminal lobes; the diencephal by the thalami; the prosencephal by the cere- brum; and the rhinencephal by the olfac- tory bulbs. G. The existence of a mesal series of communicating cavities surrounded by the endyma. H. The insignificance of the aula, the mesal cavity of the prosencephal, as com- pared with not only the other cavities but the cerebrum itself. I. The presence of an orifice, the porta (“foramen of Monro”), evidently leading laterad from the mesal aula into a cavity within the right hemicerebrum. J. The relations of the masses to the cav- ities, as are related the floors, roofs, and side walls of an edifice to the apartments. K. The great difference in the thickness of the roofs and floors at different points. L. The continuity of the side walls, floors, and (ex- cepting at one point) of the roofs. M. The existence of certain fibrous masses, commis- sures, extending across the meson, and therefore divided in this preparation. N. The lodgment of a subspherical appendage of the base of the brain (the hypophysis) in a deep pit in the floor of the cranium (the “pituitary” or hypophysial fossa). O. The change in direction of the cranial floor at about this point, the remnant of the embryonic cranial flexure. P. The similar angle formed by the base of the brain. Q. The still more decided angle formed by the general outlines of the floors of the encephalic cavities at a point nearly corresponding with the cephalic orifice of the mesencephalic cavity. R. The liability of misapprehension from the employ- ment of the ordinary descriptive terms, vertical, hort- shown. 142 “isthmus ”’ metatela - EPENCEPHAL zontal, anterior, posterior, upper, and lower, since each of these words would have one meaning for the myel and postoblongata, and another for the diencephal. It is as if two adjoining houses faced, one to the east and the other to the south. The employment of eastern and south- ern as designating structural features common to the two would be likely to cause misapprehension. 8. The convenience of regarding the entire floor as ventral, the entire roof as dorsal, any region of the brain nearer the myel as relatively caudal, and any region farther therefrom as relatively cephalic. T. The dorsal expansion of most of the segments. The wedge-like shape of the mesencephal is easily recog- nized; the thalami are not wholly exposed, but the region is more extended dorsally than ventrally; the cerebellum is much larger than the pons, while the disproportion of the cerebral hemispheres to their strictly basal, mesal part, the aula, is one of the many remarkable features of the adult human brain. U. The tendency of certain segments to overlap ad- joining parts, especially in the caudal direction. V. The lack of exact collocation between the en- cephalic regions and the cranial bones; the cerebellum corresponds to less than half of the superoccipital bone, and extends a little beyond its margin at the foramen magnum. ms epiphysis CEREBRUM optic nerve =5-r = OVO Fig. 671.—Right Side of the Brain of an Embryo 22 mm. Long and Estimated at Eight Weeks; 2,652. xX 7. flexure ; oS oe edge of the metatela; 3, pons flexure. The olfactory bulbs are not ee § 37. Prepared and drawn by B. B. Stroud (1899, a). 1, Cranial W. The collocation of the lambdoidal suture with the dorsal end of the occipital fissure. X. The location of the mesal craniometric points, nasion, bregma, lambda, and inion. § 86. The Encephalic Flexures.—These are commonly described as three, the cranial, the pons, and the neck. The second and third are temporary in man, respectively indicating the junction of the myel with the postoblon- gata and of the latter with the preoblongata. The cranial or mesencephalic flexure is a permanent feature of the human brain, as seen in Figs. 670 and 687. There is, in addition, a flexure, likewise permanent, in the diencephal so that the prosencephal is dorsad instead of cephalad of it; this persists in man and other Mammals, and in Birds. and Reptiles, but with Amphibia and “fishes” the pro- socele and diacele are on approximately the same level; see my papers, 1887, b, and 1896, d. The relative positions of the several encephalic flexures, although not their relative sharpness or the length of the intervening parts of the brain, may be indicated to the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. eye approximately by a capital W, with an oblique line (half of a V) forthe myel. Inthe accompanying diagram the three _ flexures commonly named are Pr. indicated by the words cranial, pons, and neck; Pr. stands for the prosencephal- ic region, and D. for the diencephalic flex- ure. In this diagram, D. in accordance with my custom, the cephalic (“anterior”) end is at the left. Unfortunately, however, the two figures which illus- Cranial Neck Pons Myel f FRONTAL callosum (genu) -~-- -- terma -__ & precribrum ~~~... 7 optic nerve —; y a if : Uf cs chiasma ~¥>> optic tract “7777 lura ; tuber ¥ H ; albicans 7! ; \ \ $ posteribrum +4~4*$———4- rats | j pregeniculum +4—+4, Ee i 3 OCCIPITA Sy lateral lobe vallis Fig. 672.—Base (Ventral Aspect) of the Brain. From Henle, Edinger, and nature. the ventral and lateral column ; 3, ventrimesal fissure. Brain, Brain, D. The presence of corrugations on both the mesen- cephal and the cerebrum. The former appear in many of our preparations; the latter may be artifacts. § 88. Normalization.—This term is used to include all processes by which modified or morphologically ab- normal forms and relations may be reduced, either ac- tually or ideally, to their known primitive and presumed normal conditions. Rectification would have nearly the same significance; it denotes the reduction of complex structures to simple, of irregular to regular, of crooked to straight, and of rough to plain. Examples of this process are the representation of the segments as subequal in size and on the same plane (Figs. 674 and 675); the lateral extension of the various outgrowths of the mesal eee ae OM ACLOrY fs -——- olfactory bulb , ——- ~ Olfactory crus ——-—-- presylvian f. __.- operculum _— insula — insular f. + —— Sylvian f. peduncular sulcus, flocculus - pyramid -oliva x .7. 1, Ventral (‘‘anterior’’) column; 2, line between Preparation.—The cerebellum has been allowed to fall dorsad by its own weight; thereby the occipital lobes are divaricated somewhat, the encephalic curvature is reduced, and the crura are more fully exposed. tuber, and the pia removed, together with the cranial nerve roots, excepting the optic. On the left the operculums are divaricated somewhat, so as to expose the ventro-lateral aspect of the insula. attachment. The hypophysis and infundibulum have been severed from the The right olfactory crus has been divided near its Defects:—As may be seen from profile views of the brain (Figs. 670 and 687), in the normal condition of the organ the pons and the chiasma are naturally nearly in contact, and the intervening regions, crura, etc., are practically invisible ; the ventral surface of the met- epencephal also forms little more than a right angle with that of the prosodiencephal; consequently in a direct view of either region the other is greatly foreshortened, and even the equal division of the obliquity between them shows neither to advantage. The fresh or imperfectly preserved brain, when resting upon the dorsal aspect, will, however, straighten itself, as it is commonly represented. To include so large a surface within a figure of moderate size certain details must be inadequately presented or omitted altogether. The fissures in the present figure, substantially as given by Henle, need not be regarded as signifying anything more than the general aspect of the cerebrum. trate the flexures most perfectly (671 and 676) have the reversed position, so that comparison with the diagram is less readily made. § 87. Fig. 671 illustrates: A. The general form of the brain at this stage, especially the sharpness of the several flexures. B. The size and prominence of the mesencephal and its extension over the adjoining regions. C. The distinctness of the constriction cephalad of the mesencephal as compared with that caudad, and the apparent absence of reason why the latter should be re- garded as a definitive segment any more than the former. The two crura should be equal in width. The pyramid decussation is inadequately indicated (see Fig. 689). See § 41. parts (Figs. 683 and 714); the straightening of the medi- cornu (Fig. 729); the schematic representation of the fissures (Figs. 757 and 758), and the designation of the human geniculums as pre and post rather than external and internal (§ 62, K). § 89. The Brain a Segmented Organ.—A fundamental morphological idea * of the brain is that it consists of a, series of segments, comparable, although not, probably, * Like other symmetrical organs it consists of right and left halves, approximately identical. It is also regarded by some as divisible into. dorsal and ventral zones; but this has not, I think, been demonstrated for the entire brain. 142 Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. strictly equivalent. The development and comparative anatomy of the organ can hardly be treated upon any other basis; it is recognized in the discussion of en- cephalic physiology and of psychology, and the descrip- tive anatomy of the organ is most conveniently based thereon. § 40. The segmental constitution of the human brain is invisible from the dorsal aspect (Fig. 664); hardly sug- gested when the cerebellum as well as the cerebrum is in view; more obvious from the lateral aspect (Fig. 663) ; still more so from the ventral side (Fig. 672); clearer still from the mesal aspect (Figs. 670, 687, and 756), and unmis- takable with early embryos (Figs. 671, 678, and 679), which therefore, but for practical difficulties as to procur- ing, preserving, and dissecting, would form a natural introduction to human encephalic morphology. § 41. Fig. 672 illustrates: A. The enormous prepon- derance of the visible parts of the prosencephal and epen- cephal over the other segments, thereby occasioning the common and not unnatural though very unphilosophical division of the entire brain into cerebrum (cerebrum proper, olfactory bulbs, and thalami) and cerebellum (with pons and postoblongata), the intervening narrow region, the cruraand the quadrigeminum, being regarded as merely an isthmus.* From the morphological stand- point, however, the statement would be nearly reversed. The mesencephal is at one period the most prominent and distinct region (Figs. 671 and 676). The cerebellum may be characterized as an hypertrophied bridge over the “fourth ventricle,” and there are some grounds for re- garding the PROSENCEPHAL ; __...cerebrum DIENCEPHAL olfactory te thalami bulbs as MESENCEPHAL [concealed] p rima ry, ----gemina 4 EPENCEPHAL #..cerebellum METENCEPHAL and the cer- ebral hemispheres as their secondary ap- postoblongata pendages (see my pa- «+. - MYEL per, 1887, a) RHINENCEPHAL B Tl 2 z . f olfactory bulb . Lhe extension o the cerebrum beyond all other parts of the brain, the occipital lobes overlapping the cerebellum even when the latter is allowed to displace the former. For the relations of these parts in the anthropoid apes, see my paper, 1884, g. C. The lapping of the temporal lobe over the optic tract, as shown by the two interrupted, curved lines on the right (left of the fig- ure). § 42. Fig. 673 illustrates: A. The general form of the body and limbs at this period. B. The visibility of all the en- cephalic segments, excepting the diencephal; even this may be re- garded as represented by the op- tic nerve, dimly seen through the indentation at the ventral margin of the cerebrum. C. The marked preponderance of the cerebrum. D. The absence of the transi- tory fissures; compare, however, the right hemicerebrum, as shown in Fig. 746. E. The simplicity of the other regions, better shown in Fig. 746; the cerebellum is a narrow and undi- vided mass; the mesencephal presents a slight trans- verse depression between the pregeminum and post- geminum. § 43. The recognition of the brain as a segmented Fic. 673.—Fetus Measur- ing 49 mm. from Nates to Bregma, and Esti- mated at Twelve Weeks; 1828. 1. The speci- men was received in alcohol, still enclosed by the membranes. After removal it was pinned to loaded cork and kept under alcohol during the exposure of the brain. The attitude and expression are note- worthy, and have been faithfully reproduced by the photograph and drawing ; the right side of the brain is shown in Fig. 746, and the dorsal aspect was published in the New York Medi- cal Journal, February 16th, 1884, p. 177. * This, the “isthmus cerebri’’ of some writers, must not be con- founded with the ‘isthmus rhombencephali’’ of others, which in- eludes a portion only of the mesencephalon (see Table I.). 144 organ is not dependent upon the determination of the exact number of segments, their equivalency, or their boundaries. The postoblongata represents several poten- tial segments or neuromeres, but practically it may be regarded as one. Some even regard the entire oblongata together with the cerebellum and pons as a single seg- ment. § 44. Some idea of the diversity of opinion and usage among anatomists with respect to the number and desig- nations of the definitive segments may be gained from the table published in the first edition of this work terma (viii., 114), which is sub- eT inoct stantially the same as in my paper, 1885, 6, and in PROSENCEPHAL Wilder and Gage, 1882, 405. , preerce The appended Table I. in- 3 dicates he difference be- g eainchieal tween the verbal schemas 4 adopted by the Anatom- g T nooesa ische Gesellschaft in 1895, § ee, and by the Association of epic: American Anatomists in 1897; the second is follow- METENCEPHAL ed in the present article. metacele § 45. Commentaries on the Schematic Medisected Brain, Fig. 675.—A. No two orig- inal workers in compara- tive neurology would be likely to construct schemas §& identical in all respects; the % (] rhombocsie one here presented is not | satisfactory to me and I can hardly expect it to suit others. But with all its de- fects I believe it may serve three useful ends—viz. : (a) indicate the relative posi- tion of certain parts in the floor or the roof of the gen- eral cavity ; (0) facilitate the recognition of the essential identity of the brains of all vertebrates with that of man; (c) stimulate efforts toward the construction of a more perfect schema. B. Only mesal parts are presented, 7.e., such as are ; divided in a medisection.* This excludes the cerebral hemispheres and olfactory bulbs, the lateral lobes of the cerebellum, and the elevations of the crura and quad- rigeminum at the side of the ventral and dorsal mesal furrows. C. The parietes present four degrees of thickness, viz.: (a) thin, ¢.g., the terma and the tuber in the floor, and in the roof the valvula and the lingula between the thick- ened quadrigeminum and cerebellum; (0) thick, e.g., the two just mentioned, the crura, and the oblongata caudad of the pons; (c) reinforced, e.g., the pons, chiasma, and precommissure; (7) membranous, consisting only of the endyma and the pia, constituting a tela, e.g., the roofs of the metacele (metatela), of the diacele (diatela), and of the prosocele. The plexuses (metaplexus, etc.) are special modifications of the telas (§ 24). The meta- pore is here represented as an interruption of the meta- tela. If, as now seems probable (§ 83), it is an evagina- tion, there still remains the difficulty of determining its extent, and the best mode of representing it. D. For the sake of comprehensiveness certain features are included which do not occur in all vertebrates—e.g. : the metapore (in man and a few others); the pons (mam- mals only); the medicommissure (mammals and some Fic. 674.—Schema of the Neuron (Cerebro-Spinal Axis), as if the cavity were exposed by the re- moval of the roof. The six en- cephalic segments are given a conventional spherical form, but without intending to imply that this is their actual shape or that all are separated by con- strictions. The main object of the diagram is to associate the encephalic segments with their names and the names of their cavities. * The callosum and fornix are omitted because their inclusion would have caused undesirable complications. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain. TABLE I.—COMPARATIVE VIEW OF THE SEGMENTAL THE ANATOMISCHE GESELLSCHAFT IN 1895. Partes ventrales. Partes dorsales. VI. TELENCEPHALON. hy po- ( Corpus striatum ; rhinenceph- alon ; pallium. Pars optica thalami. VY. DIENCEPHALON. Pars mamillaris hypo-{Thalamus; metathalamus; thalami. epithalamus. IV. MESENCEPHALON. Pedunculi cerebri. 4 Corpora quadrigemina. III. Isramus RHOMBENCEPHALI. ie conjunctiva; velum Pedunculi cerebri. medullare anterius. II. MeETENCEPHALON. { Cerebellum. I. MYELENCEPHALON. Medulla oblongata. Pars dorsalis. Pons. Pars ventralis. ScHeEMAS ADOPTED BY— THE ASSOCIATION OF AMERICAN ANATOMISTS IN 1897. I. RHINENCEPHALON. Bulbi olfactorii with their tracts, part of the aula and of the precommissure. II. PRosENCEPHALON,. Palliums, connected by part of the aula and part of the precommissure. III. DrzncEPHALON. Thalami, including the chiasma; genicula. IV. MESENCEPHALON. Crura and quadrigeminum. : VY. EPENCEPHALON. Cerebellum ; pons; preoblongata. VI. METENCEPHALON. Postoblongata. reptiles); the paraphysis (not found in mammals*); the chiasma (absent in teleosts). E. The dotted areas represent fibrous parts crossing the meson whether directly (precommissure) or oblique- ly (chiasma); the similar representation of the medicom- missure is not warranted by its cellular structure in mammals. F. Other differentiations of the substance of the parietes are not indicated, e.g., into the alba (white sub- stance) and the cinerea (gray). G. The hypophysis is notched and crossed by the broken line to indicate its twofold source, neural (7) and supracommissure epiphysis J. The two indentations of the cerebellum, ental and ectal, represent respectively the fastigium (§ 95) and the furcal sulcus (§ 117), but without implying their exact collocation. K. The crista has been observed in comparatively few vertebrates and its morphological significance is undeter- mined (§ 366). L. The Absence of Flexures.—Granted that no brain is perfectly straight and that many are strongly flexed in one or more places, how many flexures shall be repre- sented and what shall be their extent? The only impar- tial condition of the axis is straight (§ 38). postcommiussure peas Paraphysis. s.d. Vf Sapo cerepeuca ,metaplexus crista, ae VLaiaptexus J d.t, metapore DIENCEPHAL ae RHINENe | PROSENCEPHAL eae " MESENCEPHALSSEPENCEPHAL==METENCEPHAL==4 myelat rosscnel sulcus 2 6 Primal zone precommissure termla . chiasma tuber ‘hypophysis albicans medicommissure ‘endyma ‘Pia oblongata Fig. 675.—Provisional and Imperfect Schema of the Brain as if Medisected; intended to approximate the “least common multiple” of the brains of vertebrates above the lancelet. Abbreviations :—In the floor, at the sides of the precommissure, p. 0. designates the olfactory division (pars olfactoria) and p. t. the cerebral or temporal division (pars temporalis) of that commissure. : enteron (prehypophysis), and . the strictly nervous portion (posthypophysis) ._ dorsalis), and d. t. the decussation of the trochlear nerves (decussatio trochlearis). beginning with the most cephalic (compare Fig. 680). enteric (e) § 146. The ectal line which elsewhere repre- sents the pia enveloping the brain should not be so inter- preted for the enteric portion. H. The indentation of the precommissure merely em- phasizes the relations of its two portions to the rhinen- cephal and the prosencephal respectively (§ 364). I. The indentation of the mesencephalic roof represents the transverse furrow which—in mammals only—de- marcates the quadrigeminum into a pregeminum and a postgeminum; the former, I believe, is always the larger, but the ratio is not known tome. No attempt is made to indicate the intergeminum (“interoptic lobes” of Spitzka). *See the turtle’s brain Fig. 680. The part is briefly discussed by Minot, 1892, 690, and by StudniCka, 1895. Vioteelie— 10) In the hypophysis, e, designates the portion derived from the In the roof, s.d. designates the dorsal sac (saccus The numerals indicate the six: definitive segments M. On the same principle the dorsal and ventral out- growths, paraphysis, dorsal sac (s.d), epiphysis, and hypophysis, are made to project nearly at right angles with the brain axis. In many vertebrates the hypoph- ysis tends caudad, but in man it tends rather in the opposite direction, and in the goose-fish (Zophius) it lies far cephalad of the rest of the brain. N. The Dorsal and Ventral Zones.—It is conceded that the myel is demarcated by an interzonal sulcus (“sudews limitans ventriculorum” of His) into a dorsal zone which is sensory and a ventral which is motor; also that the sulcus and zones are represented more or less distinctly in the caudal half of the brain. On the figure the sulcus is conventionally indicated by the segmental names, mesencephal, etc., and by the three lines connecting them, But I have as yet been unable to satisfy myself of the 145 Brain. Brain. continuance of these features in the cephalic half of the brain (see § 153).* O. Comparisons will be made naturally and justly with (a) representations of the primary neural segments or true neuromeres like, e.g., that of Charles Hill (1899, 1900); (®) the schema of Prof. Wilhelm His (1898) which was adopted in 1895 by the Anatomische Gesellschaft (His, 1895); (c) that of Huxley (1871); (@) my own suc- cessive attempts, especially that in the first edition of this work, vol. viii., p. 114, which was substantially identical with that in the last four editions of Quain’s “Anatomy.” From all four it differs in the recognition of the olfactory region of the brain as a definitive seg- ment; from the first it differs also in regarding adult rather than early embryonic conditions—thus in recog- nizing the final, actual, or definitive segments rather than the primitive or potential neuromeres; from the second, in addition to minor points that may be mentioned later, it differs also in the greater regard for the conditions in the lower vertebrates; in the non-recognition of the “isthmus rhombencephali” as a definitive segment; in the method of numerating the segments and in the names of some. See also my papers, 1897, e, and 1899, c. P. The Number of Segments.—On this point the differ- ences of opinionand usage are wide and radical; my own views have changed more than once and may change again. Noone admits more fully the need of further information and of more logical interpretation. The practical question that now confronts us—investigators, teachers, and students alike—is this: In the present state of our knowledge, ignoring no known conditions of the brain, adult or developmental, and assigning at least equal weight to the lamprey and to the hag as to man, what number of transverse divisions shall be recognized, so as to facilitate the exposition and comprehension of the main features of a highly complex organ while not hindering the elucidation of the mysteries as yet unsolved? These divisions must be natural, not necessarily identical but at least comparable, and neither so few as to be use- less nor so many as to be inconvenient. The practical requirements are met by the numbers five and six. Five definitive segments were recognized in Quain and in the first edition of this work. Six are now recognized by both His and myself; but, as will be seen later, the first of mine (rhinencephal) is not admitted by him, while I am unable to see a definitive segment in the “isthmus rhombencephali.”+ Q. In regarding the olfactory bulbs, their tracts or crura, the pars olfactoria of the precommissure, and the corresponding portion of the aula, as constituting a definitive segment, the rhinencephal, I may be unduly influenced by the conditions in certain other vertebrates (Figs. 680, 790, 791, and 794) and by the considerations briefly outlined in 1897, e; but I feel that scant justice has been dealt hitherto to this probably primitive por- tion of the brain. R. The Developmental and Structural Disparity of the Segments.—Whatever number of definitive segments any anatomist admits, he will hardly claim that they are identical in either structure, mode of development, or relation to the primitive neuromeres. According to Charles Hill the mesencephal represents two neuromeres, and there certainly are several in the oblongata. 8S. The Relative Size of the Segments.—This point is an- * Burckhardt has represented the zones and other features by an elaborate system of colors ; 1895. + Should the ‘‘isthmus rhombencephali” be regarded as a definitive segment? In the early fetal brain of man, the cat, and perhaps some other mammals, there is a neck-like region just caudad of the mesen- cephal. Professor His names this region ‘*‘ isthmus rhombencephali,” and apparently regards it as co-ordinate with the other five segments recognized by him (1893, 173-174; 1895, Suppl. Bd., 157). But these same specimens, and indeed many of the figures of Professor His, present an equally distinct constriction cephalad. Even if the former represents the second of the two neuromeres which Charles Hill credits to the mesencephal, it is not easy to see why one of these regions, so insignificant in the later stages, should be reckoned as a definitive segment rather than the other. This point has been formu- lated independently by Dr. Stroud in the title of his paper, 1899, a, “If an Isthmus Rhombencephali, Why Not an Isthmus Prosen- cephali?”’ from which Fig. 671 is borrowed. 146 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. alogous to that respecting the direction of the axis of the entire brain (L). Even were the preponderance of the cerebrum in man and other mammals to be indicated the precise ratio would not be easy to fix. But in some sharks the cerebellum is very large; in Teleosts the mes- encephalic lobes are most conspicuous; in Chimaera the diencephal is greatly prolonged (W., 1877, z); in the elec- tric ray the postoblongata (metencephal) equals in size the remainder of the brain. Finally, to offset the relative in- significance of the olfactory bulbs in the Primates and their total absence in certain Cetacea, they compare favor- ably with the other segments in many Reptiles and Am- phibia, in the hags (Fig. 790) they are as wide as the cere- brum, and in the lamprey (Fig. 789) they surpass it in bulk. There seems to be no escape from the conclusion exemplified in the schema, viz., that the definitive seg- ments are potentially equal in size. T. The Numerical Designation of the Segments.—In ac- cordance with the rule (to which there is, so far as I know, but a single exception *)—viz., that the members of any cephalo-caudal series of similar parts, ¢.g., ribs and vertebrie, should be numbered beginning with the one next the head—anatomists have hitherto generally desig- nated the segment next the myel as last and the one at the other extreme as first. That plan is adhered to in Fig. 674, and throughout this article. The contrary enumera- tion was introduced by Professor His in 1893. It has been adopted by the Anatomische Gesellschaft, and there is likely to result confusion such as would attend the re- versal of the universal method of enumerating the cranial nerves. U. The Segmental Names.—As may be seen from the table of His reproduced in the latter part of the article Brain, Development of, and from the abstract of it in Table I., the most radical differences concern the two segments next the myel. The Association of American Anatomists follows Quain in designating the most caudal metencephaton and the next epencephalon. The Anatom- ische Gesellschaft follows Huxley in applying meten- cephalon to the penultimate segment and designating the ultimate by myelencephalon.+ § 46. Fig. 676 illustrates: A. The. great relative bulk of the head, constituting about one-half of the entire body. B. The indications of encephalic segmentation by slight furrows, represented by the converging lines upon the side of the head. C. The prominence of the mesencephal at this period, forming the “top of the head.” D. The sharpness of the cranial flexure, whereby two of the segments appear in a dorsal view, and two in a ventral, while the fifth appears partly in both views, as shown by Figs. 677 and 678. E. The conditions of the eye and ear; the greater dif- ferentiation of the manus than of the pes; the presence of a short but distinct tail. § 47. Fig. 677 illustrates: A. The distinctness of the myelocele (“central canal”) even to the root of the tail. B. The sudden and great expansion to constitute the © metepicele (“fourth ventricle ”). C. The marked constriction between the mesocele and the metepicele. . D. The existence, on the contrary, of the greatest *Dr. Gerrish informs me that in the famous work of Albinus, ““Tabulze sceleti et musculorum corporis humani,’’ 1747, the vertebrze, lumbar, thoracic, and cervical, are numbered from the caudal to the cephalic end of each series; nevertheless, curiously enough, the ribs are enumerated in the more usual way. + Undesirable results or concomitants of the application of myelen- cephalon to the last (most caudal) segment, and of metencephalon to the next (cerebellar) segment, are the following: (a) Disregard of ‘the prior association of epencephalon with the cerebellar segment b Owen and Quain. (b) Disregard of Owen’s prior application of mye encephalon to the entire cerebro-spinal axis. (c) Inconsistency, since the myel of myelencephalon obviously refers to the ‘spinal cord” which, however, is termed medulla spinalis. (d) The appar- ent impossibility of having an appropriate or correlated convenient word term for the cavity of the last segment. Myelocelia (Eng. myelocele) was applied by me to the cavity of the myel (canalis centralis) ; myelencephalocelia would be cumbersome; likewise ventriculus myelencephalicus. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, width of the metepicele opposite the ventral transverse furrow which is regarded by me as demarcatin g the cephalic portion (epicele) from the caudal (metacele). E. The slightness of this transverse depression of the floor. Withsome human embryos of this and later stages (Fig. 671) there is a marked flexion (the pons flexure) of this entire region, at about the middle of its length, so that the two segments are easily distinguished. § 48. Fig. 678 illustrates: A. The greater width of the mesocele than of the diacele, so that the latter might be described as merely a passage between the former and the prosocele. B. The absence of any distinct thickening of the dia- celian walls to indicate the formation of the thalami. MESENCEPHAL Fic. 676.—Right Side of a Human Embryo, 18 mm. long, and Esti- mated to be Four Weeks of Age; 274. x 6. Preparation.—The embryo was received in its membranes, and had apparently lost much of the neck curvature, so that the head is more nearly than usual in line with the body. The encephalic cavities were exposed by removing their roofs; the original outline is indicated by the broken line. C. The mesal depression in the diacelian floor, probably representing the infundibulum. D. The lateral extension of the paraceles, the cavities of the future hemicerebrums. E. The presence of an elevation of the paracelian floor, probably representing the caudatum. F. The continuity of the parietes at the junction of the prosencephal with the diencephal, and the absence of any indication of plexal intrusion at this period. § 49. Commentaries upon Fig. 679.—A. This figureisa combination of parts of Figs. 677 and 678, as if the en- cephalic curvature were obliterated. This ideal straight- ening, a form of normalization (§ 88), may be illustrated as follows: Flex the index finger upon itself as faras pos- sible; let the nail represent the prosocele, the knuckle the metepicele, and the prominent middle joint the mesocele. From either the dorsal or palmar aspect only parts of the convex surfaces are visible; but if the finger is ex- tended all fall into one view. B. The main object of this figure is to facilitate a com- parison between the encephalic cavities of this early em- bryo and those of the adult cat as shown in Fig. 686. The differences are much greater in appearance than in oO is A oO oO -ejoul | ° ® — oO ig) <4 ® < is fo) io) fa) = oO Fig. 677.—Dorsal Aspect of the Embryo Shown in Fig. 676; 274. 6. This and three of the following figures (678, 679, 681) are too deeply shaded. See § 47. Fiqg. 678.—Ventral Aspect of the Embryo Shown in Figs. 676, 677, and 679; 274. x 6. The left rie: has been removed. See § reality, consisting mainly in the reduction of most of the cavities, the thickening of most of the parietes; the great and irregular ex- tension of the later- al masses, hemicer- ebrums, containing the paraceles (“lat- eral ventricles ”). C. The resem- blance of this fig- ure to the appear- ance presented by the brain of ec- turus (a salaman- der) after the re- moval of the roof is almost startling ; see my paper, 84, a. § 50. The adult human brain pre- sents great and per- haps peculiar de- partures from the general type as on based upon embry- ‘ie ology and compara- tive anatomy, and while anatomically admirable and physiologically nearly perfect, it may fairly be char- acterized as a morphological monstrosity. Among other general features, the segmental constitution of the organ is more apparent in many lower or more general- es comas ee telI0g ee oe BLE, ~... porta } P paracele Toso- cele ae es diacele mace aeale aihe epicele on~es.-2-.. Metacele os Fic. 679.—The Encephalic Cavities of the Embryo Shown in Figs. 677 and 678 Repre- sented upon One Plane. 147 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ized vertebrates, e.g., the turtle (Fig. 680) and the hag (Fig. 782), and even in mammals where the cerebrum is less preponderant than in man. But with mammals the other segments are more easily recognized if the cere- brum and cerebellum are either tilted in opposite direc- tions as in the rabbit preparation (Fig. 681), or the former is also medisected as in the cat (Fig. 682), or both partly cut away as in the sheep (Fig. 794). § 51. Fig. 680 illustrates: A. The availability of this reptilian brain for the exemplification of certain features epiphysis dorsal sack paraphysis supracommissure geminum porta olfactory nerves on optic nerve chiasma precommissure hypophysis Fig. 680.—Mesal Aspect of the Medisected Brain of the Green Turtle, Chelone midas. 1. From nature The letters R., P., D., M., E., and Mt., designate respec- tively the six segments, rhinencephal, prosencephal, diencephal, mesencephal, epencephal, and meten- ‘The first and second are placed on the pial surfaces of the olfactory bulb and hemicerebrum ; and from the paper of O. D. Humphrey, 1894. cephal. the other four are within the cavities. of the organ; it is large as compared with that of am- phibia and most other reptiles; the cerebrum and cere- bellum do not overtop the other parts so as to obscure their serial relations; excepting the pons and callosum most of the commissures are represented; and the cranial flexure is slight (Fig. 671). B. The departure from the schematic brain in two re- spects: (a) the reduction of the mesal portion of the rhinocele and prosocele to a slight cavity, the aula, open- ing laterad by the porta; (6) the crowding of the cephalic segments caudad, occasioning the diencephalic flexure, and bringing the aula and porta dorsad of the diacele in- stead of cephalad of it. C. The elongation and close apposition of the three dor- sal outgrowths, paraphysis, dorsal sack, and epiphysis. D. The relatively large size of the olfactory bulb, and the duplicity of the olfactory nerve. § 52. Fig. 681 illustrates: A. The greater obviousness of the segmental constitution than with the adult human brain from any point of view. B. The smaller relative size of the cerebrum than in man or the cat (Fig. 682). C. The much less extent of the callosum than in man or the cat, making it possible to uncover the diencephal without the medisection required in the cat (Fig. 682). D. The presence of a distinct roof of the diacele, the interthalamic space, notwithstanding the cerebrum has been tilted. BE. The relation of this roof, the diatela, to the habenas, the ridges demarcating the dorsal and ectocelian from the mesal or entocelian surfaces of the thalami. F. The non-adhesion of the thalamus to the hemicere- brum in any way such as to indicate that the former enters into the composition of the paracelian floor. G. The more nearly equal size of the lateral (pileums) and mesal (vermis) lobes of the cerebellum, and the con- comitant absence of the vallis which is so obvious on the caudal aspect of the adult human cerebellum (Figs. 672 and 697). § 58. Fig. 682 illustrates: A. The possibility, even with so high a mammal as the cat, of making a prepara- tion that, without disturbing the essential morphological features of the organ, may exhibit portions of all of the encephalic segments excepting the last, the meten- cephal. 148 postcommissure cerebellum medicommissure B. The tendency of three of the encephalic segments to overlap those caudad of them. The cerebellum, the epencephalic roof, partly conceals the postoblongata, metencephal, in its natural attitude; in the present figure it is tilted caudad. The mesencephal (gemina or optic lobes) is covered partly by the cerebellum and partly by the cerebrum, and also at the sides overlapped somewhat by the postgeniculums, elements of the diencephal; in the. figure these bodies are in deep shadow, crossed by the line 8 on the right, and on the left by the line lead- ing to the postgeminum. Finally, the cerebrum con- ceals the diencephal and mesencephal, part of the rhinencephal, and even the cephalic slope of the cerebellum in the cat, while in man it alone is visible when the brain is viewed from the dorsal aspect (Fig. 664). C. The relations of the callosum and fornix to the two hemicerebrums, as lines of secondary ad- hesion between the two, the one dorsal and the other ventral. D. That the triangular area, hemiseptum, is real- ly only a portion of the mesal wall of either hemi- cerebrum, which has been intercepted between the two lines of junction above named. E. That the interval, pseudocele (“fifth ventricle” between the two hemiseptums, has no connection with the true encephalic cavities. F. That the callosum and fornix are in no sense parts of the roof of the diacele (third ventricle): this is consti- tuted by (1) its proper endyma, (2) the pia covering this, as all other parts of the brain, (8) the pia pertaining to the fornix, which layer of pia, with the layer (2) and the intervening vessels, constitutes the velum. G. Incidentally it may be remarked that the cruciate fissure in cats and dogs constitutes, as it were, a gash { trochlear decussation metatela myel » cerebrum » _ aulatela fimbria PROSEN- } CEPHAL ~, thalamus - postgeniculum ~~~ epiphysis ~. pregeminum DIENCEPHAL .- MESENCEPHAL , _ EPENCEPHAL ,, 7 —., 7 ~. postgeminum ~>~~_ cerebellum FIG. 681.—Dorsal Aspect of the Brain of a Young Rabbit, the Cere- brum and Cerebellum Pushed in Opposite Directions. Preparation.—While fresh, the cerebellum was tilted caudad and the hemispheres cephalad, and the velum removed ; the brain was then placed in strong alcohol so as to retain the desired shape. The segmental names are at the left, the names of parts at the right. The specimen has been lost or destroyed. ‘ across the mesal margin near the cephalic end of the hemicerebrum; it appears, therefore, upon both the mesal and the dorso-lateral aspects. The well-known and easily experimented-upon motor areas of the limbs occupy the U-shaped gyre between the cruciate and coronal fissures. It does not follow, however, that the cruciate fissure and the human central fissure are homologous (§ 303). § 54. Relative Size of the Segments in the Embryo and the Aduit.—In the embryo at one period the mesencephal is the most prominent region, and it remains the largest in : REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, some fishes; in the adult human brain it is one of the least conspicuous. § 55. Segmental Overlapping.—Although originally subequal in size, certain segments early manifest a ten- dency to extend beyond their neighbors in one or more directions. In man and the mammals generally this overlapping is in inverse ratio to the original size of the parts. The mesencephal, at one period most prominent, is encroached upon by the diencephal at the sides, by the pons ventrad, the cerebellum dorsad, and all are eventu- ally covered by the cerebrum, primarily a comparatively insignificant portion of the brain. § 56. This segmental overlapping is, upon the whole, greater caudad than cephalad, most of the segments pre- senting something like the “rake” of the mast of a ship. The cerebellum, for example, not only extends both cephalad and caudad from its connections with the epen- cephalic floor, but is tilted distinctly caudad (Figs. 670, 687, and 693). § 57. Transections at any level caudad of the aula usually affect two or more segments. This is illustrated in the following diagrams (Fig. 683). § 58. The Caudato-thalamic Fusion.—The relations of the prosencephal to the diencephal are further compli- cated by the intimate fusion of the sides of the latter (thalami) with the floors of the former (caudatums). 1(?) (From Weisker, modified.) The names at the right, doubly underlined, designate five divisions of the en- cephalocele, together with the slender myelocele (central canal of the spinal cord). The metacele and epicele together constitute the ** fourth ventricle ”’ of the text-books ; the mesocele corresponds to the aqueduct or iter; the diacele equals the * third ventricle ”’ less the aula, which is the mesal part of the prosocele; prosocele in- cludes all not already specified, viz., the mesal aula, the lateral paraceles (‘‘ lateral ventricles ’’), and the two portas through which they are continuous. The names atthe left designate the parts of the paracele, viz., the cella, extending caudad from the porta ; the precornu, extending cephalad ; the medicornu, extending in a spiral direction laterad, ventrad, cephalad, and mesad, succes- sively ; and the postcornu projecting caudad from the cella. 2is placed near the tip of the right lateral recess of the epicele. The larger part of the figure is modified from a photograph of the wax model made by Weisker, of Freiburg. The metacele, my- elocele, and part of the epicele are from a cast of the cavities in achild. The ventral aspect was chosen in order to display to better advantage the uninterrupted series of mesal cavities, and the portas. Defects.—I doubt whether any part represents the correspond- ing’cavity accurately. The portas are too long (compare Fig. 718). The diacele presents neither the orifice for the medicommissure (the presumed location of which is indicated by the dotted circle (1) just caudad of the portas) nor the marked ventral extension toward the hypophysis. The medicornua are not sufficiently curved; in reality the extremity of each approaches the diacele within about 2.5 cm.; the postcornua are too short; the bound- aries of the epicele are vaguely and perhaps incorrectly indicated, and the lateral recesses (2) should be longer. paracele forms (Dipnoans, etc.); with birds and frogs the mesen- cephal is markedly tripartite (Fig. 682); with man and other mammals, and likewise with some other verte- brates, the epicele presents more or less extensive “lateral recesses” (Figs. 669, 684, 698). The embryonic dien- 150 ~~~ prosocele +) ——=— $= diacele epicele ., metacele myelocele cephal protrudes at either side an optic vesicle that be- comes the retina and optic nerve. § 61. Mig. 684 illustrates: A. The continuity, general form, and relative size of the several divisions of the adult human encephalocele, as viewed obliquely from the ventro-dextral aspect. B. The obvious triplicity of the prosocele, and the existence of lateral extensions of the epicele. C. The slenderness of the mesocele as compared with its relative size in the embryo (Fig. 680) and in the adults of some other vertebrates (Fig. 685). D. The general modifications of the primitive and typical condition of the encephalic cavity which led the older anatomists, and still lead some of their modern successors, to regard the whole as compris- ing four “ventricles,” a first and second (lateral), a “third,” and a “fourth,” the aula being ignored and the mesocele considered merely as a “ passage from the third ventricle to the fourth.” § 62. Hig. 686 dllustrates: A. An arrangement and circumscription of the encephalic cavities in the adult cat (an accessible mammal), essentially identical with that in the human adult (Fig. 735) and fetus (Fig. 716), and in vertebrates generally. B. The great differences in size and shape be- tween the various divisions of the encephalocele; the mesocele is little larger than the myelocele, and istubular; the diacele is narrow but high; the meta- cele wide but shallow; the epicele is very irregular; the myelocele is patent throughout, while in man it is nearly obliterated. The epicelian lateral recesses are not exposed, so the triple constitution of a typical segmental cavity is exhibited only by the prosocele, with its mesal, aula, and lateral paraceles. C. The different constitution of the celian pari- etes. The roofs of the aula, portas, and metacele are membranous telas, with plexuses on the ental surface. D. The reduced thickness of the parietes near the rima, constituting the fimbria, one of the riparian or marginal parts. E. The apparent interruption of the wall of the medicornu at the rima (“ great transverse fissure ”). On close examination, however, although the proper nervous parietes are absent, the intruded pial fold (paraplexus) is seen to be covered by the endyma reflected from the adjoining parts, so that the in- jected alcohol was completely confined. F. The not very obvious relation of the ectal furrow, hippocampal fissure, to the ental elevation or colliculus, hippocamp; on the right the line from postgeniculum crosses the end of the fissure, which is not otherwise indicated. G. The relations of the alba (medulla) to the ectocinerea (cortex) and the entocinerea (“central tubular gray ”); olfactory nerve olfactory bulb % cerebrum thalami geminum > cerebellum : postoblongata ' 1 meee toe 2 hypophysis optic nerve Fic. 685.—Left-hand figure: Brain of Frog Seen from the Left After Removal of Parts of the Left Side; 654. x 1.5. Right-hand fig- ure: Enlargement of the Geminum (Mesencephal), so as to show more distinctly the lateral cavity of the mesocele and the orifice (comparable with the porta) by which it communicates with the mesal cavity. the metepencephalic entocinerea has been removed in ex- posing the cavities, but it is distinct and abundant at the sides of the mesocele (aqueduct), of the diacele, consti- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain. tuting the thalamus, and of the prosencephalic precor- nu, constituting the caudatum and—unexpectedly—the hemiseptum and column of the fornix, all which were distinctly gray in the fresh preparation. H. The caudal extension of the cerebrum so as to reach the cerebellum, and thus conceal the lateral aspect of the intervening segments, diencephal and mesencephal. I. The fusion of the thalamus with the caudatum, of the diacelian side wall with the paracelian floor. The line of junction of the two segments may be regarded as indicated approximate- ly by the word dien. J. The absence or in- conspicuousness of the cinerea _ __ lenticula, claustrum, and Aiba aie ge insula (compare Fig. 782). : oye K. The less width of cent die aie reso the diencephal than in caudatum | _ man, so that the genicu- lums maintain their prop- fornix ~~ __ er morphological relation of cephalic (pre) and cau- dal (post), rather than of « severe si lateral, or “external,” and pregeniculum __ mesal, or “internal,” as in : man. rima _ L. The extension of the Paranieeaae paraceles, the proper cav- ities of the hemicere- medicornu _-/ brums, caudad from the F aula even farther than fimbria _ cephalad, thereby war- : : ranting the diagrammatic hippocamp --— representation of the par- __ postgeniculum - - -- aceles as lateral exten- nC ae sions, not cephalic only. M. The absence of a 1 eae a postcornu in the cat as in pileum .-——< most other mammals, the exceptions being man, monkeys, seals, porpoises, a and some dogs. apiplextss=——=—— N. The distinctness of the crista in the cat. It is not named on the fig- ure, but may be seen as a conical elevation at the cephalic side of the aula; the line from aula points at it. EPENCEPHAL COT a Fic. 686.—The Encephalic Cavities of a Cat, Exposed from the Ventral Side; 479, concomitant completeness of the celian circumscrip- tion. C. The non-communication of the pseudocele with the true cavities. (The meninges and blood-vessels are con- sidered under Fig. 801.) $§ 66. In tracing the continuity of the endyma at the meson it is best to begin with a region where a rupture could hardly occur in either floor, roof, or sides, and where also a transection is most readily effected when — pseudocele _' precornu -” - Lae _- aula o- - ae. - _ _- porta - eter - Pa _- 7 paracele (cella) _--— diacele eas -- medicornu -— mesocele ae rea: a= epicele —= metacele 4 ~ myelocele xX 2. 1, The valvula, § 63. Celian Cirewm- scription.—The facts of development and compar- ative anatomy, and anal- ogy with other hollow organs warrant the pre- sumption that the ence- phalic cavities communi- cate only with one another and with the myelocele. Any communication with the ectal surface is pre- sumably artificial, except- ing, perhaps, at the meta- which is so thin in the cat that the cerebellar folia show dimly through it (the line is interrupted just above the L of EPENCEPHAL); 2, the narrow space between the lateral aspect of the mesencephal and the overlapping hemicerebrum ; in anthropotomy this is commonly reckoned as part of the ** great trans- verse fissure’; 3, obliquely cut surface, left by the removal of the caudatum and adjacent parts of the left hemicerebrum. Preparation.—The brain was exposed from the ventral side and left in the calva for better support. the cavities were alinjected so as to harden the parietes and keep them apart. Successive slices were removed until the portas and aqueduct (mesocele) and myelocele were exposed. With a narrow- bladed knife the walls of the diacele (including the medicommissure), epicele, and metacele were cut away obliquely; also on one side (the right of the preparation, but the figure is reversed so that it appears on the left) the caudatum, hippocamp, and part of the thalamus, so as to expose the continuity of the precornu and medicornu. The olfactory bulbs were removed with the ventral portion of the cerebrum. The boundaries of the cinerea (cortex, etc.) and alba (medulla) were ascertained by com- paring the similarly exposed surface of a fresh brain ; some of the differences between the two sides are due to a slight difference of the section-levels. Defects.—The brain should have been prepared in a chromic-acid solution, or injected with the red mixture, so as to differentiate the alba and cinerea. the entire brain is to be studied in two parts, a cerebral pore (“foramen of Magendie”) and the lateral recesses 4§§ 78, 98). ; § 64. Hndymal Continuity.—The endyma is the essen- tial and absolutely constant constituent of the celian parietes; hence in all figures purporting to illustrate celian circumscription the line representing the endyma should be distinct and uninterrupted, excepting where discontinuity has been demonstrated. § 65. Fig. 687 illustrates: A. The sharpness of the cranial or mesencephalic flexure in man. Compare the sheep (Fig. 794) and the turtle (Fig. 680). B The continuity of the endyma lining the mesal series of cavities excepting at the metapore, and the and a cerebellar portion. This “place of election” is the mesocele (“aqueduct” or “7¢ter a tertio ad quartum ventriculum ”). A. Theendyma covering the floor of the mesocele may be traced caudad (actually almost directly ventrad) with slight depressions and elevations through the oblongata to the myel where it lines the slender myelocele, the “canal of the cord.” B. Recommencing at the same point in the mesocele, the floor endyma turns quite sharply ventrad over the cephalic curvature of the crus, passes the albicans, and reaches a region where the floor is thin and frequently 151 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. torn in removing the brain. This is the tuber, commonly called’ “tuber cinerewm,” which is continuous with the infundibulum, and thus with the hypophysis. The cephalic part of the tuber is reinforced by the chiasma, pseudocele auliplexus fornix - supracom- missure dura SX gon / i precerebral a. Ce copula / / ey, A ont aula / a, (bay) precommissure / \ \ ! terma \ chiasma hypophysis albicans ! postcribrum crus 1 \ myel'! : myelocele F1G. 687.—The Mesal Cavities of an Adult Brain Exposed from the Left, with Their Immedi- 5. Fig. 801 represents the entire meson of the same specimen on a ate Parietes. X .65. smaller scale, and its mode of preparation is there described. Defects.—In addition to those specified under Fig. 801, the most serious are: (@) the non-representation of the postpontile recess, the mesal depression just caudad of the pons, shown in Fig. 702, 2; (b) the presence of the line curving dorso-caudad from the rostrum of the callosum; (c) the imperfect indication of the membranous parietes of the dorsal sac, the pouch lying upon the epiphysis; (d) the non-designation of the diacele. the ental margin of which presents a marked transverse ridge, sloping caudad into the tuber and cephalad into the optic recess. In Figs. 689 and 708, the chiasma and tuber are shown with the hypophysis attached; but in Fig. 672 it is detached, leaving an orifice, the lura. C. Directly dorsad from the chiasma, the cephalic wall of the diacele is the terma (lamina terminalis, or 1. cine- rea), So thin and delicate as not infrequently to be rup- tured during the removal or manipulation of the brain. The proper nervous material of the terma seems hardly more substantial than the lining endyma and the cover- ing pia, here represented by the ental and ectal lines. The ectal aspect of the terma is shown in Fig. 711. D. Suddenly there is a marked thickening of the cephalic wall, from the reinforcement, so to speak, of the terma by a fibrous cord, oval or elliptical in section. This, the precommissure, connects the olfactory bulbs and portions of the cerebrum upon opposite sides, and hence belongs to both the rhinencephal and prosencephal; the cavity just caudad and dorsad of it is the aula, the mesal portion of the rhinocele and prosocele; $$ 362-864. E. From the precommissure caudad to the roof of the mesocele the course of the endyma is extremely irregular, and the nature and shape of the roofs are very diverse. The immediate roof is largely membranous, and the con- dition is further complicated by blood-vessels large and small, and by plexuses. Finally, the parts lying directly upon the meson differ materially from those just laterad of it, and as the chances are altogether against a medi- section being exactly mesal in the whole of its course, 152 = valvula Mx metapore there is nearly a certainty that upon the first inspection one will miss anticipated features and see what one does not understand. F. The recognition and comprehension of the actual facts in a given preparation will be fa- cilitated by consulting the diagram (Fig. 725), and the representations of the brains of the cat and rabbit (Figs. 681 and 682). The important point to bear in mind is that the complete cir- cumscription of the mesal encephalic cavities would be unaffected were the entire cerebrum removed, including the callosum, hemiseptum (the lateral wall of the pseudocele), and fornicom- missure (the mesal continuity of the fornix), down to the point where the heavy line representing the endyma leaves the narrow, white area repre- senting the fornicommissure to cross the convex surface of the fornicolumn and be reflected upon the auliplexus. The details of this, the aulic and portal region, are more clearly seen in the en- _-~ lingula larged figures of the porta (Figs. 721 <7-- epicele and 719). G. From the auliplexus (at or very near the meson) or from the portiplexus. (if the section plane passes through the right or left porta instead of the mesal aula) the endyma may be traced caudad upon the ventral surface of a mem- branous fold, the velum. Strictly speaking, between the endyma and the velum, which is a fold of pia, inter- venes the remnant of the primitive nervous roof of the diacele. This may persist in some animals, but in the adult cat and in man, so far as I am aware, there is practically nothing between the pia constituting the velum and the endyma. At each side of the meson there depends a more or less distinct. vascular fringe, the diaplexus, continu- ous with the auliplexus, the portiplex- us, and thus with the paraplexus, these last three being successive mem- bers of the prosoplexus. H. The relations of the endyma to the velum and plex- uses are more clearly shown in Fig. 782, representing a transection of the diacele. There also are shown the re- lations of the habena. This is a low ridge following a curved line along the mesal aspect of the thalamus from the dorsal end of the porta to near the epiphysis; it is covered by endyma, but just dorsad of it, dimly seen in the figure, is a shallow furrow, the habenal sulcus, from which the endyma is reflected first dorsad, and then me- sad, upon the velum and the diaplexuses. The habena unites with its opposite (fellow of the other side) at the supracommissure. The endyma line is seen to leave the velum, and descend to the dorsal (really cephalic) surface of the epiphysis, whence it extends cephalad to and over the margin of the supracommissure, then into and out of the epiphyseal recess, and over the convex cephalic sur- face of the postcommissure; thence it enters the meso- cele, where the tracing of its continuity was begun, only it is now the lining of the roof, the geminal bodies, in- stead of the floor. I. Continuing caudad, there is but slight change in the direction of the roof of the mesocele; a great reduction in its thickness occurs in the transition from the postgem- inum to the valvula. The succeeding part, the lingula, is somewhat thicker and trends slightly dorsad, to become continuous with the cerebellum proper. The cavity here resembles a gable roof, with a sharp dorsal angle. The caudal slope is formed by the nodulus, a compara- tively massive mesal lobe; but from its margin, common- ly more rounded than appears in this figure, the endyma REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, TABLE II.—PROVISIONAL GROUPING OF SomME NeEuRAL Parts ACCORDING TO THEIR SEGMENTS AND SOME 2. Chief OTHER CHARACTERS. 4, Membranous 6. Thin and which it can be stated confi- dently what is normal, or how frequently certain peculiarities occur. § 68. Classification of _ the Parts of the Brain.—The fore- going account.of the brain as a whole constitutes an intro- duction to the description of each of the six segments, be- ginning with that immediately succeeding the myel. § 69. Commentaries wpon Table II.—A. It is substan- tially identical with Table VII. in my paper, 1896, h. Compare the tables in the first edition of this work (1889, @), * The subject is treated with un- usual fulness by Krause, 1889, 192-195. 1. Segment. Raettnont 3. Cavity. portion. 5. Plexuses. riparian parts. 7 Hepes 8. Some other parts. I.| Rhinen - i - i i i i i i i ae - ceph pe olfac-| Rhinocoelia. ... on arate rciclolststarcitlcte sterai|iersiele ist e.cyorn evettarece ee ae : i = : ° aeehg tN limen, II.| Prosencepha-| Cerebrum....| Prosoccelia (in-| Prosotela (in-| Prosoplexus| Tenia, fimbria,) Preeeommissura Pallium insula, len- lon. cluding the} cluding the} (including the| pala, terma. (pars temporalis), ticula, caudatum mesalaulaand| mesal aulatela} mesal auliplex- callosum, fornix. paraphysis. : mea fay para- ae SF maak ena lateral III.| Diencepha-| Thalami..... Diacoelia ...... ateed tiene te Habena ....... Supracommissu ra,} Postcribum, tuber, hy- lon. medicommissura,| pophysis, : epiphysis, IV.| Mesencepha- | Quadrige mi-| Mesocoelia.....| Mesotela(in the}................ Valvula........ Pouteoaint elite Orn Sus erieth lon. num. lamprey). decussationes teg- crusta, lemniscu 3, V.| Epence pha-| Cerebellum. .| Epicoelia...... |.....+5..- seteniyets Epiplexus..... Lingula........ pan shen 3 senpGac Prepitoueuia anal VI. ae Posto blon-| Metaccelia Metatela Metaplexus Metapor' lig-| D Spoken ee gees pie sayy peer | MLCtAtCl aces see back Lp pele ig- eeatie pyrami- Syren oliva, trape- VII.| Myelon...... Myelon...... Myelococliaz 1.5. 1, Emergence area of the trifacial nerve, the larger the sensory root, the smaller the motor; 2, the fibre arciforme partly encircling the oliva; 3, line of emergence of the accessorius and of the dorsal roots of the spinal nerves; 4, continuation of the lateral column of the myel; 5, line of emergence of the ventral roots of the spinal nerves ; 6, ventral column ; 7, ven- tral (mesal) fissure: 8, myelocele: 9, dorsal (mesal) fissure; 10, funiculus gracilis, the oblongatal continuation of the myelic dorso- mesal (*‘ posterior median’) column, enlarging cephalad into the claya; the clava and funiculus together are sometimes called ** pos- terior pyramid’’; 11, ‘‘ posterior median fissure”; 12, funiculus cuneatus ; 13, the shaded band represents the mesal portion of the metacele (caudal part of the ‘‘ fourth ventricle ’’) between the restes (“‘restiform bodies’’) of the two sides; 14, acoustic tubercle, over which run the acoustic strize, which are not shown; 15, tubercle of Rolando, the continuation of the unspecified funiculus of Rolando, interpolated between the funiculus cuneatus and the emergence line of the dorsal roots. ; ; Defects.—Although good in general form and showing the oliva and its arciform fibres (2) with unusual distinctness, the specimen does not exhibit the several columns very clearly, and the lines of demarcation, excepting the ‘* posterior median fissure,”’ are taken from other preparations and from figures; this applies also to the lines upon the pons indicating the passage of the caudal fasciculi entad of the cephalic. The dotted lines demarcating the sectional areas of the peduncles are only approximately accurate. The facial ae acoustic nerves are not shown, or the acoustic strize (see Fig. 393). adjoining segment. In reality, however, not only do the cephalic and caudal margins overhang the adjoining sur- faces to a certain extent (see Fig. 702, 1 and 2), but it is by no means certain that the pons covers no more and no less than the epencephalic portion of the oblongata. In 156 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. the sheep and cat, for example, the trapezium, here in- visible, is exposed (Fig. 794), while with many lower vertebrates the pons is rudimentary or absent altogether, and the boundaries between metencephal and epencephal must be otherwise determined; e.g., the turtle, Fig. 680. C. The lapping of the cephalic portion of the pons over the caudal, giving the appearance of a twist or rota- tiou of the medipeduncle upon its own axis to the extent of the fourth of a circle. D. The relation to the oliva of the arciform fibres (2), which appear to be derived from the pyramid and to pass around the caudal end of the oliva to enter into the com- position of the restis and postpeduncle. E. The projection of the right clava beyond the left, a marked lack of symmetry in this specimen. F. The ripa, or line of demarcation between the gen- eral, pial surface of the myel and oblongata, and the en- dymal, metacelian surface. The ripa consists of the pia and endyma with, in some specimens (Fig. 702), a thin intervening lamina of nervous substance. G. The prepeduncular fossa, a shallow depression on the dorso-lateral surface of the prepeduncle, near the medipeduncle. § 86. The visible longitudinal divisions of the postob- longata do not correspond altogether with the myelic columns. The ventrai column (Fig. 672, 7, Fig. 689, ca, Fig. 692, 6) continues cephalad partly in the pyramid of the same side, as would naturally be expected, but mostly dips entad of the pyramid and oliva and forms longitu- dinal fasciculi near the meson farther dorsad. § 87. Of the lateral column (Fig. 689, e/, and Fig. 692, I) a large part crosses at the decussation (shown in Fig. 689, but not always visible) to constitute mainly the pyramid of the opposite side. Some of the fibres join the restis of the same side, constituting the “direct lateral cerebellar tract.” The rest of the lateral column dips en- tad of the oliva and “forms the longitudinal fibres of the substantia reticularis grisea.” § 88. The dorsal column of the larger portion of the myel is displaced in the cervical region by the dorso- mesal (“posterior median”) column (Fig. 692, 10); this, in the postoblongata, is called funieulus gracilis. Near the apex of the metacele it presents a distinct enlarge- ment, the clava (Fig. 692), cephalad of which the funicu- lus is no longer distinct. Between the funiculus gracilis and the lateral column (Fig. 692, 4) there intervene, in the postoblongata, two funiculi, of which the more lateral (15) is regarded as the direct continuation of the dorsal column of the myel, but is commonly called funicuius of Rolando, sometimes “lateral cuneate”; between it and the dorso-mesal column (funiculus gracilis) intervenes another interpolated funiculus, the cuneate (12); this and the funiculus of Rolando appear to enter into the com- position of the restis (“restiform body ”) which is con- tinued as the postpeduncle into the cerebellum; but, ac- cording to Quain, this relation is rather apparent than real, the components of the restisand postpeduncle being (a) the arciform fibres (Fig. 692, 2) from the ventral column, and (0) the “ direct cerebellar tract ” of the lateral column. : : § 89. The increased bulk of the postoblongata is due also in part to the entrance (or exit) of the roots of the accessory, hypoglossal, vagus, and glosso-pharyngeal nerves, which are more numerous than the spinal nerve roots upon a similar length of the myel (see Figs. 672 and 689). § 90. Fig. 693 illustrates: A. The general topographic relation of the cerebellum to the segments just cephalad and caudad, and to the ventral portion of its own seg- ment, through the three pairs of peduncles, prepeduncle (5), postpeduncle (8), and medipeduncle (the cut area crossed by line 5 on the right and by lines 3, 4, and 5 on the left). B. The tendency of anatomical writers to ignore the existence or traces or morphological significance of the thin or membranous portions of the encephalic parietes (see my paper, 1891, 5). REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, IV. EPENCEPHAL.—§ 91. Synonyms.—Epencephalon; metencephalon; cerebellar segment; hindbrain. § 92. Principal Parts.—Floor: preoblongata and pons. Roof: cerebellum and lingula. Sides: peduncles. “Cavity: epicele with lateral recesses. Ectocinerea: cortex. Entocinerea: dentatum, fastigatum, embolus, globulus. Chief cerebellar divisions: (mesal) vermis: (lateral) pileums (“hemispheres”). Flocculus and para- flocculus. § 98. Boundaries.—The epencephal may be defined as including as much of the brain tube as intervenes. be- ~ VAL fi Nees Fig. 693.—Dissection of the Peduncles. 0.5. (From Quain, after Sap- pey, and Hirschfeld and Leviellé.) 1, Mesal sulcus; the line crosses the middle of the wide cut surface of the medipeduncle; 2, mesal sulcus at the place of emergence of the acoustic strive; 3, postpe- duncle, continuous with the restis; the cut end of the postpeduncle is crossed by the line, 2; 4, the clava, the swollen portion of the fu- niculus gracilis; 5, prepeduncle; 6, lemniscus; 7, lateral sulcus of the crus; 8, pregeminum, the postgeminum just caudad. Preparation.—On the left, the three peduncles are cut short; the right half of the cerebellum is cut obliquely, and tilted laterad, so as to show the connections of the prepeduncle and postpeduncle. Defects.—There is no evidence of the lines of division, ripas, of the endyma in exposing the metepicele (‘‘ fourth ventricle ’’), or of the existence of the valvula and lingula between the prepeduncles. tween the membranous portion of the roof (metatela) and the decussation of the trochlearis nerve, together with the corresponding regions of the floor and sides and the encompassed cavity, the epicele. § 94. Fig. 694 illustrates: A. The general aspect of the adult cerebellum from the side. ‘B. The location of three main sulci, furcal, cacuminal, and peduncular. § 95. Epicele-—The epencephalic cavity includes the cephalic (“anterior”) portion of the “fourth ventricle ” together with its dorsal extension (fastigium) into the cerebellum, more or less triangular in form. According to Blake (1898-1900, 89-90) the cavity of the cerebellum has at first a greater dorso-ventral extension which is reduced by the fusion of the opposed walls. § 96. Lateral Recesses.—By this name are commonly known the pair of extensions of the “fourth ventricle ” laterad and ventrad (Figs. 684, 695, and 698). Their walls are partly membranous (metatela) and partly substantial (sides of oblongata, peduncles of flocculus, and certain nerve roots). They might with equal appropriateness, perhaps, be described under the metencephal, and the difficulty in determining the segmental assignment is very naturally included by Blake (1898, 104) among the reasons for the non-recognition of two segments in this region. § 97. Fig. 695 illustrates : A. The embryonic continuity of the endyma and more substantial elements of the parietes around the lateral recesses at this stage (see § 98). B. The corrugation of the thin portion of the par- epicelian parietes preparatory to the formation of the epiplexus. § 98. Outlets of the Lateral Recesses.—Although closed in the embryo (Fig. 695) the ventral ends of the recesses are commonly described as open, constituting communi- cations with the subarachnoid space even when the meta- pore does not exist. I have been disposed to regard these peduncular sulcus flocculus Fig. 694.—Left Side of the Cerebellum of an Aged White Man ; 3,434. <1. (From Stroud, 1897, a.) The outlines were drawn with the camera lucida. orifices as artifacts from the readiness with which the membranous adhesions of that region are torn during the removal and examination of the brain according to cus- tomary methods. But the histological and embryological researches of Blake seem to show that in man and in mam- | | | parietes 4 Fig. 695.—Transection of the Brain of an Embryo Rabbit, Sixteen Days Old. (From KOlliker.) 65; enlargement of part of Fig. 669. mals generally the ends of the recesses are opened by the more or less extensive disappearance of the membranous parietes. § 99. Fig. 696 illustrates, in addition to points also shown in Fig. 694: A. The great depth of the furcal sulcus. B. The absence of the lingular foliums (§ 119). § 100. Preoblongata.—The floor of the epicele is the preoblongata, continuous with the postoblongata and with the crura. In the turtle (Fig. 680) and other non- mammals there is no obvious line of demarcation. 157 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. > markedly reinforced by a transverse fibrous mass, the pons, that it is easily recognized; but the width of the fureal s. ‘ postramus. metapore FIG. 696.— Mesal Aspect of the Cerebellum of an Adult Male Negro; 3,118. x 1. Traced from a photograph. (From Stroud, 1897, a.) : pons varies so greatly that its margins can hardly be ac- cepted as the boundaries of the entire segment. Compare the turtle (Fig. 680) with the sheep (Fig. 794) and man (Figs. 672 and 689). § 101. Pons.—In mammals the preoblongata is so peduncular sulcus ' cacuminal s. bellum, the pollex the short and sharply curved post- peduncle, the index the longer and less curved prepe- duncle, and the other three fingers the intermediate and thickest medipeduncle, continuous with its oppo- site through the pons. § 105. Hig. 697 tllustrates: A. The lapping of the tonsillze over the uvula. wy Pr B. The location of the flocculus and the com- mencement of the peduncular sulcus. C. The relative position and size of the three pe- duncles. § 106. Flocculus and Parafloceulus.—Attached to the medipeduncle by short peduncles of their own are small foliated masses, the flocculus (in two lobes) and the paraflocculus (in one) (Figs. 698 and 701). Contrary to the implication of the names, the paraflocculus is really attached mesad of the floceu- lus; in Fig. 698 they are twisted so that the reverse appears to be the case. The peduncle of the floc- culus forms part of the wall of the “lateral recess ” (Fig. 698). Little is known of the functions of these parts or of their homologues in other animals. According to Stroud (p. 96) the paraflocculus is much larger in the cat and capable of division into: a supraflocculus and mediflocculus. § 107. Fig. 698 tllustrates: A. The location and form of the flocculus, with its two divisions and. rounded folia, and of the smaller paraflocculus, presenting but slight traces of foliation. All are attached to the medipeduncle, and the flocculus is. sometimes called the peduncular lobe. B. The general location of the lateral recess. (2), or parepicele, between the peduncles cephalad, the restis and other parts of the postoblongata mesad, and the flocculus stem laterad; its peculiar relations. with the glosso-pharyngeal and vagus nerves are in- adequately shown and need special preparation and § 102. Peduneles.—At and near the meson the connec- | study. tions of the cerebellum with the adjoining segments are thin; the lingula is relatively atrophied (Fig. 702) and the metatela wholly membranous (Figs. 670 and 687); but laterally the cerebellum has massive continuations, constituting three pairs of peduncles: a cephalic (prepedun- cles) to the mesencephal; a caudal (postpeduncles) to the metencephal and myel, and an intermediate (medi- peduncles) to the pons, part of the same segment. § 108. The peduncles constitute a continuous mass of alba at either side, but their relative positions and extent are pretty well determined by various methods, anatomical, microscopical, and experimental. The medipeduncle is the largest and most lateral; it is mainly continued from the lateral lobe of the cerebellum to the pons, where the fibres cross the meson, interdigi- tating with their opposites, and form- ing a relation with the cinerea. The postpeduncle mainly connects the ver- mis with the restis, while the prepe- duncle connects chiefly the dentatum with the mesencephal and parts far- ther cephalad. The dorso-lateral as- pect of the prepeduncle presents a distinct shallow depression, the prepe- duncular fossa (Fig. 692). § 104. The relative location and di- rection of the three peduncles on the right side may be illustrated by the digits of the right hand. Hold the hand with the fingers down, the thumb pointing backward, the index forward, and the other three fingers, slightly overlapping, outward between them. The palm may then represent the cere- 158 C. The twisting of the peduncles of the flocculus and paraflocculus whereby their real attachments are appar- ently reversed. The paraflocculus, although its name. pyramis ~— ¢ cuneiform lobe peduncular sulcus prepeduncle nodulus flocculus medipeduncle lingula epicele postpeduncle Fic. 697.—Caudal (** Lower’”’ or ‘‘ Posterior ’’) Aspect of the Adult Cerebellum. A little less: than natural size. (From Edinger, inverted and slightly modified.) 1, Part of the right quadrangular lobe. The cut ends of the peduncles are dotted ; the large medipeduncles extend latero-dorsad into the lateral lobes; the flocculi are attached to the medi- peduncles. The continuity of the vermian divisions with those of the lateral lobes is. not apparent upon this aspect. Defects.—In addition to the general remark made under Fig. 700 the following special deficiencies are to be noted: (1), There is no line to represent the divided endyma of the metatela along the caudal (here upper) side of the cavity (epicele) ; all this region requires elucidation in respect to celian circumscription ; (2), the omission of the plex- uses and nerve roots; (3), the postvermis should be more deeply shaded to indicate its depth below the level of the tonsillae, which also are really almost in contact; (4), on coop hs ee Fig. 700, the vermis should present a line indicating the reflexion of the arachnoid. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. suggests a lateral position, really is attached mesad of the flocculus; see Fig. 701. § 108. The cerebellum is essentially an arch over the epicele (cephalic part of the “fourth ventricle”) (Fig. y floceulus medipeduncle | _ paraflocculus It metacele leet 243 pontiraphe Fic. 698.—Caudal Aspect of the Right Flocculus and Adjacent Parts ; 2,238. > 2. 1, Endymaat the left side of the epicele; 2, right lateral recess, laid open; 3, oliva; 4, pyramid; 5, trifacial nerve; 6, ab- ducens; 7, facial; 8, acoustic; 9, glosso-pharyngeal; 10, recess latero-dorsad of oliva. Preparation.—The cerebellum was removed by division of the peduncles to near the floor of the epicele, and the postoblongata by a transection just caudad of the pons; the lateral recess (2) had already been torn open, as usual, in removing the brain, and its en- tire extent and exact form are not determinable from this prepara- tion (see Fig. 684). 699). This condition exists in the embryo, and per- sists in many of the lower vertebrates. The adult human organ, however, is a foliated mass of complex fibrous and cellular structure, well meriting the adjective hypertrophied, applied to it by E. C. Spitzka. § 109. Fig. 699 illustrates : A. The large size of the epi- cele at this period, as compared with the thickness of the parietes. B. The ex- tensions _lat- ero - ventrad constituting the parepi- celes or “ lat- eral recesses” (compare Figs. 384 and 895). C. The non-appearance of the mesal lobe, vermis, at this period and the absence of sulci upon the lateral masses, pileums. D. The continuity of the riparian part, a, the kilos (“ posterior velum ”), along the line of junction of the ectal pia and ental endyma, they not being represented distinctly; if their torn edges were distinct they would con- stitute the cestus. The cestus and kilos indicate the line of attachment of the metatela. § 110. Aspects of the Cerebellum.—In the natural condition of the adult brain the rounded margin of the cerebellum demarcates two surfaces looking re- spectively “upward” and “down- ward.” But in accordance with the general principle of normalization (§ 38) and by analogy with the simpler case of the epiphysis (§ 154) the cere- Fic. 699. — Caudal Aspect of the Cerebellum and Oblon- gata of a Fetus. (Size and age and magnification un- certain, specimen and notes having been lost; it proba- _bly resembled quite nearly the specimen shown in Fig. 373.) a, The kilos. postsemilunar lobe peduncular sulcus quadran Fig. 700. — Cephalic (‘‘ Upper” or *‘ Anterior’’) Aspect of the Adult Cerebellum. inger, inverted and slightly modified ; a little less than natural size. portion of the central lobe. Defects.—The original figure is obviously diagrammatic; it was selected as more clear than usual, and as representing the general interpretation of the foliar arrangement on this aspect of the cerebellum ; I am not, however, satisfied in all respects, and regret that I cannot determine certain points upon my own preparations, so as to base the figures upon them entirely. These remarks apply equally to Fig. 697. Braib, Brain. bellum is here regarded as if projecting dorsad at right angles with its supporting portion of the brain- axis, the oblongata (Fig. 702). The two main surfaces become therefore cephalic and caudal, but they are not sharply delimited. § 111. Pileums and Vermis.—The adult cerebellum comprises a mesal lobe, the vermis, and two lateral masses, the pileums, commonly called “hemispheres.” On the cephalic aspect, the vermis (prevermis) is promi- nent (Fig. 700); but on the caudal the lateral lobes project decidedly beyond the postvermis, the surface of which is thus at the bottom of a deep mesal crevice, the vallis (“vallecula”) (Fig. 697). § 112. Foliwms, Sulei, and Lobes.—The entire surface of the adult cerebellum presents numerous lines, for the most part parallel and having a generally transverse direction. These lines represent crevices of greater or less depth, the sulci, and the intervening thin plates are the folia. Certain of the interfoliar crevices are so con- stant, deep, or distinct as to warrant the recognition of the intervening groups of folia as lobes. The commonly received division of the two regions of the cerebellum into lobes is indicated upon the figures. I am free to admit, however, that I am by no means fully satisfied therewith. § 113. Fig. 700 illustrates: A. The natural tilt caudad of the cerebellum, so that its normally cephalic surface looks dorso-cephalad, even when the oblongata is held in the cephalo-caudal plane. B. The extension of the cerebellum, so as to overhang the postoblongata. C. The enormous preponderance of the pileums (lateral lobes) over the vermis (mesal lobe) in the adult; compare however, Fig. 699. D. The slight demarcation between the vermis and pileums on this aspect. E. The appearance of part of the postsemilunar lobes, and of the peduncular sulcus, both these appearing partly also upon the caudal surface. F. The connection of the two cacuminal (presemi- lunar) lobes by means of a single folium, the cacumen. § 114. Cortex (ectocinerea).—Each folium consists of a central lamina of alba and a covering of cinerea having a peculiar cellular structure; see the article Histology of the Brain. vant gular lobe central lobe lingula valvula prepeduncle From Ed- 1, The ala or lateral 159 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. § 115. Peduncular Suleus (“great horizontal fissure”). —When the flocculus and paraflocculus are removed, or the overlapping foliums of the cerebellum are separated from them and from one another by the removal of the pia, the non-foliated lateral surface of the medipeduncle is easily seen to continue laterad and dorsad for about 1 cm. between the tiers of foliums on the cephalic and the caudal aspects. This interval is the beginning or stem of what iscommonly called the “ great horizontal fissure,” but which, from its obvious relation to the medipeduncle, I have called peduncular. By most writers it is repre- sented as continuing along the dorsal (“ posterior”) mar- gin of the cerebellum and as demarcating the cephalic and caudal aspects of the entire organ. In particular it is regarded as meeting its opposite at the meson just caudad of the cacumen, a single thin folium which, at either side of the meson, enlarges and becomes a subdi- vided cacuminal (“ presemilunar ”) lobe. § 116. The Peduncular Sulcus Incomplete as a Land- mark.—But, while it is perfectly possible, with most pregeminum. - - postgeminumr ~ prepedunele. ..- medipeduncle - } culminal lobe. B. B. Stroud, del, Fic. 701.—Diagram Showing the Divisions of the Human Cerebellum as If Extended in One The line between the cacuminal lobe and the tu- beral lobe should be designated peduncular sulcus C* horizontalis magnus’’). Plane. (From Stroud, 1897, b, 108. ) specimens, to recognize a deep sulcus of the pileum which passes caudad of the cacumen and trends laterad in the direction of the medipeduncle, an inspection of the depths arouses doubts of its essential continuity and morpho- logical significance. § 117. Furcal Suleus.—On various grounds, especially comparative anatomy and development, Stroud has con- 160 cluded (1897, a, 6) that the primary and most constant sulcus, and the one which should be held to demarcate the two main regions of the cerebellum, is one which leaves the stem of the peduncular sulcus opposite the at- tachment of the paraflocculus and passes at right angles across the cephalic surface, dipping between the ad- jacent foliums so deeply as to more nearly reach the cavity than any other of the sulci. As seen in Table III. the furcal is the preclival sulcus of Schifer. § 118. The region. cephalad of the furcal sulcus is divided by the culminal sulcus (postcentral of Schiifer) into the culminal lobe and the central lobe. § 119. Lingula.—When the central lobe is lifted or removed there will be exposed the valvula, the thin zone of the mesocelian roof, and caudad of it, completely overhung and concealed by the adjacent parts of the cerebellum, a series of three, four, or five transverse di- minutive foliums; see the medisection (Fig. 702). At birth the lingular folia are rounded and distinct, but in the adult they are relatively smaller, often flattened as if by pressure of the overhanging cere- bellum, and sometimes (at least in cer- tain negro and insane brains) nearly or completely absent.* The cephalic foli- um is narrowest and has a rounded outline (Fig. 700): the pia adheres quite firmly to these folia, so that they - are liable to be torn off. § 120. Mig. 702 tllustrates: A. The mesal topography of the cerebellum and adjacent parts when brought into nearly their “normal position,” 7.e., when the metepencephalic floor is nearly horizontal (cephalo-caudal) and when the longer axis of the cerebellum is nearly dorso-ventral; this is nearly their condition in a body lying prone, with the axon and longer portion of the neuron (myel) approximately hor- izontal, as with most quadrupeds and the majority of walking and swim- ming vertebrates (see § 9, and the arti- cle on Terminology, Anatomicaly. For comparison with Figs. 670, 687, and 756, this or they must be regarded as turned about one-fourth of a circle. B. The exact number and form of the cerebellar folia and subfolia at birth, so far as they appear upon an approximate medisection. C. The combination of the folia to form lobes, more or less well defined. D. The arboriform arrangement, whence the name arbor vite (herein mononymized to arbor). E. The topographical relations of the mesal lobe (vermis) to the lateral lobes; caudad, dorsad, and at the ven- tro-cephalic region the lateral lobes project beyond the vermis, but the latter is the more prominent with the culmen at the cephalic side and with the nodulus at the caudo - ventral angle. The interval between the lat- eral lobes on the caudal aspect consti- tutes the vallis. F. The enormous size of the cere- bellum as compared with its cavity, even had the dorsal part of the latter been maintained at its natural size by alinjection. G. The projection of the cerebellum beyond its attach- ments and proper cavity. Cephalad, it overhangs not only the valvula, but the postgeminum, these being parts of the mesencephal; caudad, whatever exact limit be as- * The lingula has not been recognized in the apes, but Stroud is in- clined to regard as its homologue what he described (1897, b, 120) as a ‘cephalic’ lobe in apes and in certain human brains, ¢é.g., Fig. 698. signed to the epicele, the vermis covers the entire “fourth ventri- cle.” H. The distinctness of the four lingular folia, constituting the transition from the massive cerebellum to the atrophic (?) val- vula. I. The prominence of the cephalic and caudal margins of the pons, and the concomi- tant depth of the pre- pontile and postpontile recesses. J. The merging of the dorsal commissure of the myel and post- oblongata into the obex, and of this into the ligula; in the adult this latter seems to be hardly more than the combined pia and en- dyma (see Fig. 692), but in the child’s brain from which this fea- ture was derived, al- though the meninges had been removed, there was, neverthe- less, a distinct lamina of nervous substance. § 121. The divisions of the caudal region of the cerebellum can- not be seen complete- ly unless the _ post- oblongata is forcibly bent ventrad or cut away; indeed the en- tire oblongata and pons may advantageously be removed by tran- section of the pedun- cles ventrad of the floc- culi as in Fig. 697. § 122. When the pil- eums are divaricated the postvermis caudad of the cacumen is seen to be at first narrow, then wider, and then decidedly compressed. The wide portion is the pyramis; the short region between it and the cacumen, the tuber; the longer portion of the remainder is the uvula crowded between subglobular divisions of the pileums, the tonsils. Fi- nally, and seen with some difficulty, is the nodulus, a group of three or four foliums, connected at either side by the kilos with the flocculus. The relations of these parts to one another and to the lateral masses and to the Vermis. sulci are indicated upon Table IV. "TABLE III.—SYNONYMS OF THE PRINCIPAL SULCI OF THE CERE- BELLUM; STROUD, 1897, a. Preferred. 1. Central sulcus. 2. Culminal sulcus. 3. Furcal sulcus. 4. Cacuminal sulcus. 5. Peduncular sulcus. ‘6. Pyramidal sulcus. 7. Uvular sulcus. 8. Nodular sulcus. Vou. II.—11 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. furcal sulcus -——= furcal sulcus w= V(t an Brain, Brain, ug evan sulcus pyramidal sulcus ~=-— pyramis oe ——— pyramis =) 9 ih. = =="pyramis tonsilla uvula 7. clava 5 ligula Re ! cae valvula f a } H ) lingula 7 / r obex i nodulus ' } mesocele ; ee ss. Myelocele ; / epicele metacele EPENCEPHAL METENCEPHAL Fic. 702.—The Metepencephal (Cerebellum, Oblongata, and Pons) of a Child at Term, Showing the Approxi- mately Mesal Aspect of the Right Half; 478. x3. Traced from an enlarged photograph. (This is the same specimen that is shown in Fig. 756, where, however, no attempt was made to represent details, and the cerebellum is more nearly in its * ‘natural attitude.” 1, Prepontile recess; 2, postpontile recess (fora- men ccecum) ; 3, presumed caudal end of the pyramid; between 3 and 4 there might be—but were not seen—indications of the pyramid decussation (Figs. 672 and 689) ; 5, slight elevation of the metacelian floor ; the triangular darker area just ventro-cephalad represents the postfovea ; 6, the dorsal extension of the epi- cele into the cerebellum ; 25, metatela (diagrammatic). Defects.—The plane of section passed slightly sinistrad of the meson; hence certain features are not exactly what would have appeared upon a precise medisection. On the cut (unshaded) surfaces the alba and cinerea are not distinguished, the latter having been bleached by the alcohol. The pons section does not show the fibres of the raphé. The cavities were not alinjected and hence are unnaturally small. The meninges were removed; so there is no indication of the dorsal attachment of the arachnoid to limit the subarachnoid space, and the obex, ligula, and metatela are supplied from other specimens, but the extent of the metapore (foramen of Magendie) is not shown. When the drawing was made, the significance of the furcal sulcus had not been recognized. Dr. Stroud has kindly revised the identifications. He would limit the prevermis to so much as is cephalad of the fur- cal sulcus ; but for the present 1 retain the original designations of the two regions of the vermis. The sul- cus just cephalad of the cacumen is the cacuminal ; that just caudad is the peduncular, deep in the pileum eo but shallow at the meson. The tuber is the part between the peduncular and tuberal sulci. ee TABLE IV.—SYNONYMS OF THE LOBES OF THE CEREBELLUM; FROM STROUD, 1897, a. SLIGHTLY MODIFIED. ; VARIOUS TERMS PREFERRED. SCHAFER. eae Vermis Worm and hemi- : . and pileum. sphere. Hemisphere. Lobus lingulz....../Frenulum ling- ule. = : 1. (Lingu-|1. Lingular lobe..|1. Lobus centralis..|Ala lobuli cen- Schafer. la?), Ceph- tralis. 1. Sulcus precentralis. alic lo be, : 2. Sulcus postcentralis. variable 3. Sulcus preclivalis. 2. Centrall2. Central lobe...|2. Not recognized 4. Sulcus postclivalis. lobe. as a distinct 5. Sulcus horizontalis magnus. lobe. c Sulcus postgracilis. 3. Culmen..|3. Culminal lobe .|3. Lobus culminis .. ola lunatus an- . Sulcus intragracilis. erior. 6. Sulcus pregracilis. } Lara sul- s. postpyramidalis. eras 7. Sulcus prepyramidalis. 4, Clivus ...|4. Clival lobe..... 4. Lobus clivi,..... Lobus lunatus 8. Sulcus postnodularis. 4 posterior. 161 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. TABLE IV.—SYNONYMS OF THE LOBES OF THE CEREBELLUM; FROM STROUD, 1897, a, SLIGHTLY MODIFIED.—Continued. TERMS PREFERRED. SCHAFER. peaveens i Vermis Worm and hemi- ; Vermnis. and pileum. sphere. Hemisphere. 5. Cacumen |5. Cacuminal lobe|5. Lobus cacuminis.|Lobus postero-su- perior. Presemilunar lobe. 6. Tuber .../6. Tuberal lobe.../6. Lobus tuberis....|Post paid ce ha 18 lobe. Lobus postero-in- ferior. a. pretuberall..... Raeisjelelv'e sealateiviel Che hie SEMI NaTIS lobe. inferior. b. medituberal |........... oeeeeeeee (0. Slender lobe. lobe. L. gracilis pos- terior. C. POSTLUID OG lh iecrciee Ceireenisianices c. L. gracilis ante- lobe. rior. 4 7. Pyramis..|7. Pyramidal lobe.|7. Lobus pyramidis.|Cuneiform lobe. L. biventralis. 8. Uvula....|/8. Uvularlobe....|8. Lobus uvule..../Tonsilla. Amygdala. 9. Nodulus ./9. The -nodulus/9. Lobus noduli.....|Flocculus. does not ex- tend laterad into the -pil- eum. The flocculus is a separate di- vision. It is not a part of the pileum (or hemisphere). § 123. Fig. 703 illustrates: A. The constitution of the dentatum asa corrugated capsule of cinerea, open cephalo- ventrad. B. The entrance of the fibres of the prepeduncle through the hilum of the dentatum to connect with its cells. § 124. Hntocinerea.—Upon a medisection of the organ there would appear to be only alba and ectocinerea, the Fic. 703.—The Dentatums and Prepeduncles. direction of the prepeduncles as shown in Figs. 692 and 693. Defects.—By an inexcusable oversight the prepeduncles are not indicated by a line and the name ; but they are readily recognized as the fibrous tracts at the sides of the epi- There is no representation of the “ fleece,” the layer of fibres radiating from the ectal surface of the dentatum. cele, converging from the dentatums to the geminum. former branching in a tree-like manner, whence the name arbor (vite). But in the central part of the cerebellum, near the apex of the epicele, are four pairs of masses of cinerea sometimes called roof-nuclei or tectal nidi. There are reasons for thinking that the primitive cerebellar ento- 162 . cinerea of the dentatum fibres of the dentatum rimula (From Stilling, somewhat modified.) Preparation.—The plane of section was oblique, so as to coincide with the general cinerea has been displaced, and is represented by these masses enumerated in their order from the meson laterad: Fastigatum; globulus; embolus; dentatum. § 125. The Dentatum.—This is the largest and most. easily recognized of the four masses; (see Figs. 703 and 704). It has the form of a corrugated capsule, open dentatum Fig. 704.—The Dentatum and Other Masses of Cinerea in the Centra} Part of the Cerebellum. From Stilling, somewhat modified. * 2—. Preparationv=—This is commonly designated as a “horizontal” ' section. Really, the plane cannot be indicated in such simple terms. The central part of the figure, including the cinereal masses, is through the fastigium, the roof of the apex of the epicele. Defects.—No attempt has been made to represent the fibrous con- stitution beyond the purely diagrammatic indication of the cephalic (anterior) decussating commissure. meso-ventro-cephalad, for the reception of the fibres of the prepeduncle (Fig. 703). In any cerebellum, whether fresh, or hardened in chromic acid compounds, or even alcohol, it is readily recognized upon transections or upon sagittal sections begun about 1 cm. either side of the meson and continued laterad for 2 or 8 cm. The dentatum has received the following additional names, of which the last only is used with any frequency: Nucleus dentatus ; corpus denticulatum, s. fimbriatum, s. lenticulatum, s. ciliare ; Eng., ciliary body. § 126. The Fastigatum.—This, more often called “fastigial nucleus,” is close to the meson, directly in the roof (fastigium) of the epicele; Fig. 703. It is rounded cephalad, but the caudal end presents two or three projections. § 127. The Embolus and Globulus. —These smaller masses of cinerea lie between the dentatum and the fas- tigium, and somewhat dorsad of the latter. Their forms are indicated by their names, and are well shown in Stilling’s figure as reproduced in Fig. 704. More common (and cum- bersome) titles are nucleus globosus or globuliformis, and nucleus emboli- — postpeduncle fo rms: OF § 128. Hig. 704 illustrates: A. The Globull existence, near the apex of the epi- cele, of four pair of cinereal masses, representing, perhaps, dislocated por- tions of. the cerebellar entocinerea. B. The lack of precise symmetry in the forms of these masses; of the globuli there are three on the left and two on the right, the more cephalic probably representing two. V. MESENCEPHAL. —§ 129. Syn- onyms: Mesencephalon; midbrain. Tabular arrangement of parts: Chief parts: quadrigeminum and crura. Cavity: mesocele (aqueduct or iter.) Floor: crura. Sides: gemina: Roof: gemina and valvula. Ectocinerea: cappa. Entocinerea (“central tubular gray”). Commissures: postcommis- sure, trochlear decussation. § 130. In early embryonic stages the mesencephal is the most conspicuous region of the entire brain, but con~ Pee REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. sists of a single, thin-walled vesicle, with a relatively large cavity (Figs. 671 and 677). As the parietes thicken, two furrows appear upon the dorsal aspect; a mesal, demarcating the left elevation from the right, and a transverse, subdividing each of these into a cephalic and a caudal portion (Fig. 678); there results, in the adult mammalian brain, the formation of four approximately similar elevations, whence the names, corpus quadri- geminum, corpora quadrigemina, optic lobes, etc. In the present article they are called gemina (twin bodies), pre- geminum and postgeminum (Figs. 693 and 707). They constitute.the larger part of the mesocelian roof. § 181. Valoula.—A caudal portion of the mesocelian roof retains nearly its primitive tenuity as a transparent lamina, the valvula, between the gemina and the lingula (Fig. 702). Its cephalic part presents some slight corru- gations, either a mesal furrow anda pair of lateral ridges, the frenulums (Fig. 706), or a mesal ridge in addition. § 132. The fibres of the trochlearis nerve decussate in the valvula. It is practically convenient, although not perhaps quite correct, to regard the trochlear decussa- ‘tion as the boundary between the mesocelian valvula and the epicelian lingula (see Fig. 675). § 133. Mesocele.—In all mammals what Tiedemann picturesquely described as a “ vast and spacious cavity ” becomes relatively an insignificant tubular passage, which has been called “aqueduct” and 7ter a tertio ad quartum ventriculum. As may be seen from Figs. 670, 687 and 756, it is expanded or trumpet-shaped at the cephalic end, and irregular in form at the caudal; the intermedi- ate, longer part varies considerably in different indi- viduals, being sometimes nearly cylindrical, but usually a transection presents points in two, three, or four direc- tions, lateral, ventral, dorsal; the departures from the cylindrical shape are more frequent and distinct in the postgeminal and valvular portion (see Figs. 687, 706, and 708), and may be regarded as vestiges or suggestions of the potentially tripartite condition which is actually pres- ent with birds and frogs (Fig. 685). § 134. Lemniscus and Brachia.—The lateral slope of the mesencephal presents three megascopic features, the lemniscus, postbrachium, and prebrachium, shown in Fig. 706; in the former the fibres run approximately cephalo-dorsad, in the latter obliquely dorso-ventrad; their course and con- nections are considered in the article Brain, Histology of the, as is also the extent of the ectocinereal lamina called cappa. The lemniscus and its connec- tions have been discussed at consider- able length by E. C. Spitzka, 1884, e. § 185. Hntocinerea.—This is the least modified of all portions of the ence- phalic “central tubular gray ”; it forms a layer 2 to 3 mm. thick surrounding the mesocele. § 186. The Crura (crura or peduncult cerebri).—Excepting the parts already named, the mesencephal consists mainly of a pair of fibrous masses (Figs. 672 and 689) containing the compacted mo- tor and sensory conductors between the regions caudad, whose relations are mainly with the body, and the regions cephalad, which are the organs of the mind. Each crus consists of two re- gions, a ventral, the crusta, and a dor- sal, the tegmentum (Figs. 706 and 708). § 137. Intercalatum (substantia ni- gra, locus niger).—A transection through the crus at almost any level reveals a dark mass (Figs. 706 and 708) of crescentic outline, approximately dividing the section into a ventral third and a dorsal two-thirds. Its lateral and mesal borders correspond to the furrows called sulcus lateralis and s. oculomotorius. The name commonly employed refers to the distinctly dark color (due to pigment in the cells) of the mass in man and caudatum. postgeniculum lemniscus * optic tract postecribrum Brain, Brain, some apes; but the absence of color in other mammals has led E. C. Spitzka to propose a name referring to its more constant character of intercalation between the ventral crusta and the dorsal tegmentum; the locative mononym be eye by the Association of American Anatomists in ; § 188. Postcommissure.—The cephalic margin of the mesocelian roof is of moderate thickness, and curved - epiphysis > supracommissure: - epiphyseal recess - postcommissure +-— mesocele tegmentum -=-~—7- intercalatum ay a | crus Fig. 705.—The Postcommissure and Adjacent Parts; 2,239. 1.5. Preparation.—The diencephal was transected just cephalad of the postcommissure ; the diatela was torn away to admit more light ; the space just above the epiphysis was occupied by the dorsal sack. The figure should be compared with the medisections (Figs. 670 and 687), and with the dorsal aspect of the region (Figs. 707 and 708). dorsad so sharply as to present a cephalic convexity (Fig. 705) and a caudal concavity (Fig. 687). Osborn has suggested that it is intersegmental like the trochlear de- cussation (Fig. 675). § 139. Mig. 705 tllustrates: A. The appearance of this aspect of the postcommissure as a cylinder. B. The considerable size of the epiphyseal recess; al- though a mere diverticulum within an apparently func- tionless organ, it is larger than the cephalic orifice of the mesocele in this specimen. C. The distinctness of the supracommissure (commis- sura habenarum). frenulum valvula | aqueduct prebrachium a regeminum postbrachium | postgeminum \ tegmentum Fig. 706.—Caudal Aspect of the Mesencephal and Part of the Diencephal ; 2,360. X 1.5. 1, Tenial sulcus; 2, right postgeniculum ; 3, right pregeniculum. Preparation.—A well-hardened, alcoholic, adult brain was transected just cephalad of the pons, at a level indicated nearly by the line from crus in Fig. 707. A block containing the thalami and adjacent parts was then cut out by incisions in various directions, the fornix peeled off, and the velum and other parts of the pia removed ; the ink lines near the sides marked ripa indicate the lines along which the lateral margins of the velum, the paraplexuses, were torn away. Defects.—More should have been left at the sides and ventrad. On the left, the roughly indicated curved line just laterad of the tenia was due to inadvertence, and may be disregarded. See § 140. D. The location of the dorsal sac upon (morphologi- cally, cephalad of) the epiphysis; see Fig. 687. E. The modified relative position of these parts. Ina less modified condition of things, the two commissures and the epiphysis should all lie nearly in one plane; but the pressure of the superincumbent cerebrum has made 163 Brain, Brain. the long axis of the epiphysis cephalo-caudal instead of dorso-ventral, and left the two commissures and the two orifices in a dorso-ventral series instead of a cephalo- caudal. § 140. Fig. 706 illustrates: A. Segmental overlapping. The thalami and geniculums project caudad beyond the intersegmental line, and the caudatum is here directly laterad of the thalamus instead of cephalad; consequently a transection through the pregeminum would divide not only the mesencephal, but also both the diencephal and the prosencephal. B. The caudal extension of the thalamus as a rounded eminence, the pulvinar, on which, at the right, the word thalamus is placed. C. The existence of two other eminences on this aspect of the diencephal, the postgeniculum, mesad and more distinct, and the pregeniculum, laterad and less distinct. With lower mammals the general mass of the thalamus is less developed than in man, and the pregeniculum is not only still less prominent, but also decidedly cephalad, so that the prefixes pre and post are much more appro- priate. D. The continuity of the optic tract with both the geniculums, more obviously with the pregeniculum. E. The nearly complete concealment of the pregemi- num, in this view of the parts, by the postgeminum; the former is seen at the left to project slightly. F. The location and forms of the postbrachium and prebrachium; the former is between the two geminums, the latter just cephalad of the pregeminum; as they pass ventrad they embrace, as it were, the postgeniculum. G. The location of the lemniscus, just caudad of the postbrachium. H. The T-shape of the mesocele in this specimen. I. The thinness of the mesocelian roof, here constituted by the valvula, with a mesal furrow and lateral ridges, the frenulums. J. The relatively extreme thickness of the mesocelian floor, constituted by the crura. K. The division of each crus into a ventral crusta and a dorsal tegmentum, the boundary between these two regions being defined partly by the lateral furrow, op- posite the word erus, on the left, and partly by a pig- mented tract, the intercalatum, not here seen, but shown in Figs. 705 and 708. L. The deep ventral depression between the crura, constituting an intercrural area. M. The presence, at the cephalic end of this area, of several rather large foramina for the transmission of arterial branches, whence this part is called postcribrum (“posterior perforated space”). N. The trefoil outline of the mesencephalic transection due to the mesal and the two lateral depressions. O. The obviously and unquestionably pial and ecto- celian character of all the natural mesocelian surfaces. P. The equally unquestionable continuity of these sur- faces over the geniculums to the pulvinar. Q. The absence of anything like a ripa on the visible surface of the thalamus until we reach the sharp and irregular line so marked at the left. R. The endymal and entocelian character of the slender natural surface of the caudatum. 8. The continuation of this endymal surface upon the visible length of the tenia. T. The significance of the ripa as not only a boundary between contiguous pial and endymal surfaces, but as indicating where the margin of the paraplexus or some membranous continuation of it has been torn away. § 141. Mig. 707 illustrates: A. The segmental overlap- ping of the diencephal at the side of the mesencephal and of the prosencephal at the side of that (see § 55). B. The division of the caudatum (the entocelian por- tion of the striatum) into a cephalic, enlarged caput and a caudal, slender cauda. C. The unlike topographical relations of these two parts, in that the caput is uncomplicated, while the cauda has a slender, marginal (riparian) band at its mesal side, the tenia, having peculiar relations with other parts. 164 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. D. The location of the diacele between the two thalam\ and its continuity with the aula. E. The presence of the medicommissure (seen somewhat better in Fig. 709). F. The relation of the callosal genu to the intercerebral fissure and the pseudocele; but for the callosum the intercerebral f. ‘cortex medulla postcommissure supracommissure pregeminum postgeminum prepedunde Fig. 707.—Dorsal Surfaces of the Caudatum, Thalamus, and Gemina. (From Henle, reduced and slightly modified.) 1, Tenial sulcus; 2, fimbrial sulcus; 3, habenal sulcus; 4, trigonum; 5, “anterior tu- bercle”’ of the thalamus. Preparation.—The dorsal portion of the cerebrum has been re- moved, including the callosum, fornix, velum, paraplexuses, and diatela; also the pia covering the epiphysis’ and mesencephal. Defects.—The shading is too deep and does not indicate the dis- tinction between the pial and the endymal surfaces. The caudal parts of the thalami are crowded mesad, and the gemina are not Well shaped. fissure and thegpseudocele would be continuous, as would also the hemiseptum with the general mesal wall of the precornu. G. The demarcation of the mesal, entocelian surface of the thalamus from the dorsal, entocelian surface by a rough edge just dorsad of the habena; here it is repre- sented by the narrow, white line between the two black ones, and designated as the habena; it is really a ripa along the dorsal side of the habena (see also Figs. 687 and 739). H. The presence of three shallow furrows on the dor- sal surface of the thalamus; a dorso-mesal, just dorsad of the habena, the habenal sulcus; a lateral, correspond- ing nearly with the mesal edge of the tenia, the tenial sulcus; an intermediate and oblique, corresponding with the lateral margin of the fimbria (removed), the fimbrial sulcus. I. The demarcation of the dorsal surface of the thala- mus, which is pial and ectocelian, from the adjoining surface of the caudatum and tenia, which is endymal and entocelian, by a sharp, irregular line at the mesal edge of the tenia, constituting a ripa. This line was intro- duced into the figure; it is absent in the original, as in all similar figures known to the writer, excepting Fig. 16, in Meynert’s “ Psychiatry,” where it is called “linea aspera,” without, however, any reference to its morpho- logical significance. J. The vague and unsatisfactory representation of the parts at the porta. This region has yet to be cleared up in respect to the relation of the pial and endymal surfaces; it was my inability to show these relations clearly upon original preparations that led me to employ the present figure provisionally. K. Incidentally it may be remarked that both this and REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, the previous figure exemplify the advantages of that feature of the simplified nomenclature which consists in the designation of members of natural or artificial groups of parts by words compounded of the generic terms and prefixes indicating relative position; e.g., pregeminum and postgeminum; pregeniculum and postgeniculum; precommissure, medicommissure, postcommissure, and supracommissure. V. DrencepuaL.—§ 142.—Synonyms: Diencephalon, deutencephalon, thalamencephalon, interbrain, *tween- brain. ‘Tabular arrangement of parts: Chief parts: thalami. Cavity: diacele. Floor: tuber, chiasma, and diaterma. Sides: thalami. Roof: diatela (practically the velum). Plexuses: diaplexuses. Commissures and decussations: medicommissure, supracommissure, chi- asma. KEctal elevations: albicantia, pregeniculums, and postgeniculums. Perforated areas: precribrums and posteribrum. Ental elevations: habena. Ectal de- pressions: trigonum, habenal, tenial, and fimbrial sulci. Ental depression: aulix (“sulcus of Monro”), Append- ages: hypophysis, epiphysis, and dorsal sac. With the adult of man and all other mammals the primitively thin sides of the diencephal are greatly thick- ened and become the thalami, with the geniculums (pre- and post-) as latero-caudal elevations. The relations of the diencephal to the entire brain are well indicated in the young rabbit (Fig. 681). § 143. The pregeniculum and postgeniculum are repre- sented in Figs. 706 and 707, and described in connection therewith; the optic tract and the chiasma are shown in Figs. 689 and 711, and considered in connection with the optic nerves in the article, Cranial Nerves. § 144. Mig. 708 illustrates: A. The form, direction, Se eer prehypophysis optic n. infundibulum 1 optic tract 2 tuber albicans crus posteribrum ocuRmotor nerve erusta intercalatum ; crus 4. tegmentum J mesocele postgeminum Fia. 708.—The Tuber (tuber cinereuwm) and Adjoining Parts; 706. x 1.5. (The same region is shown in Figs. 672 and 689, upon a smaller scale.) 1, Expanded proximal end of the infundibulum, covering the lura, which is exposed in Fig. 672; 2, a slight elevation between the tuber and the optic tract. The irregular line across the tuber and optic tracts represents the cut or torn edge of the pia, which adheres quite firmly to the chiasma. The black spots repre- sent the foramina in the postcribrum and elsewhere through which vessels passed; the triangular region laterad of the chiasma is a part of the precribrum (‘‘ anterior perforated space’). Preparation.—The brain was removed with great care, the hy- pophysis being extricated from its fossa by dividing the dural folds in several cirections with the sharp point of a scalpel, and then in- troducing the blunt-pointed syringotome. Defects.—The natural surfaces of the crura should have presented amore fibrous appearance (somewhat as in Fig. 689), and another preservative than alcohol would have differentiated the cinerea on the cut surface. The albicantia have perhaps the appearance of overhanging the postcribrum too far, but this is more nearly correct than the usual representation, as, for example, in Figs. 672 and 689. The left intercalatum should be shown more nearly like the right. and complete separation of the albicantia; they are usu- ally represented (as in Figs. 672 and 689) as hemispherical elevations; here they are seen to be elliptical in outline, their longer axes converging caudad, and the caudal ends overhanging the postcribrum; in the sheep (Fig. 794) and in mammals generally the albicantial sulcus is a shallow depression or wholly absent. B. That the hypophysis is wider than long, and con- sists of two parts, conveniently called prehypophysis and posthypophysis ; the latter is the smaller and partly as it were let into an emargination of the former. C. The expanded base of the infundibulum (1). D. The raised, unnamed area (2) at either side of the tuber. EK. The demarcation of the crusta from the tegmentum by the intercalatum. F. The slight, angular extensions of the mesocele, which sometimes is almost circular in outline. § 145. The diacelian floor is various in direction and composition. Beginning with the mesencephalic floor, the crura (Fig. 687), there is a marked decrease in thick- ness in the region of the postcribrum (which may really be common to the two segments), as well as a deflection of the floor ventrad; the albicantia (Figs. 672, 689, and 708) constitute lateral thickenings, and then the floor is re- duced to an atrophied lamina comparable with the val- vula; this, with the shorter, thin part just cephalad of the intervening and dependent hypophysis, constitutes the tuber (tuber cinerewm) and infundibulum. The fusion of the stems of the primitive optic vesicles to form the chiasma, and the fusion of this with the other- wise thin diacelian floor, confers upon the latter in this region considerable thickness and firmness, but this part is again succeeded by the atrophied terma (Figs. 687 and 711), strictly the diaterma, in distinction from the proso- terma dorsad of the precommissure. Although the dia- terma has a nearly dorso-ventral direction, it should properly be regarded as part of the floor, since the aula, the mesal division of the prosocele, is constructively ceph- alad of the diacele, although actually more nearly dorsad. § 146. Hypophysis (pituitary body or gland, Figs. 670, 687, and 708).—This has a twofold origin, viz., from the neuron (posthypophysis) and from the enteron (prehy- pophysis); see the article Brain, Development of. Herd- man thinks it may have been an ancestral sense organ (American Naturalist, 1888, p. 1127). At present, not- withstanding its constancy throughout the vertebrates, its function is still in doubt, but the not infrequent co- existence of acromegaly with lesion of the hypophysis merits careful consideration.* § 147. In marked contrast with the massive sides the diacelian roof is, for the most part, very thin, consisting apparently of the endyma only, closely attached to the ventral or diencephalic layer of the velum, from which are developed the parallel diaplexuses (Figs. 716 and 782) dependent at either side. Cephalad, the diatela is con- tinuous with the aulatela, or perhaps directly with the fornix dorsad of the aula and portas; caudad, it extends for some distance beyond the proper diencephalic bound- ary, is reflected ventrad upon the dorsal (properly cephalic) aspect of the epiphysis to constitute the dorsal sac, and is then continuous with the supracommissure, and the epiphysis itself (Fig. 687). § 148. Mig. 709 illustrates: A. The size, form, and connections of the medicommissure; it is relatively smaller than in other mammals (Fig. 688), and slightly constricted about its middle; if isolated it would have the form of a pulley-wheel with a shallow groove. B. The relations of the mesal aula to the portas and to the diacele (see § 163). C. The thinness of the lamina uniting the two halves (columns) of the fornix. This lamina must be regarded as the primitive prosocelian terma as high as the dorsal limits of the porta, and may, therefore, be called the prosoterma. * On this subject articles have been published by Woods Hutchinson in the New York Medical Journal for July, 1900. 165 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. § 149. Habena (habenula); (Fig. 687).—At the dorsal margin of the mesal surface is the habena, a slight ridge, with a dorsal convexity, extending from the porta to the supracommissure, which unites it with its opposite. pseudocele hemiseptum precorme caudatum endyma fornix —medicommissure thalamus -diacele Fic. 709.—The Medicommissure and Adjacent Parts; 20382. 1.3. (Compare Fig. 707, where some of the same parts are shown on a smaller scale.) Preparation.—The brain was removed with care so as not to tear the medicommissure, and alcohol was injected per luram so as to harden the parietes and keep them apart. ‘The prefrontal lobes were then removed, thus opening the precornua and exposing the caudatums; with these as guides the block containing the medicom- missure was safely isolated; the thalami are cut away almost to the level of the commissure. See § 148. Along the dorsal side of the habena is the habenal sul- cus, and the two represent nearly the line of reflection of the endyma from the mesal surface of the thalamus upon the roof: of the diacele (see Figs. 681, 687, 707, and 732). § 150. Fig. 710 illustrates : “A. The overlapping of the cerebrum upon the diencephal, so that the transection of one includes the other. B. The folding of the pia covering the now apposed dorsal surface of the thalami and the ventral surface of Ahm pia velum LWA i Be { 1a \ \ PROSENCEPHAL .cerebrum Tostrum callosum™ ? ¢ fornix DIENCEPHAL thalamus Fic. 710.—Diagrams Illustrating the Relations of the Callosum, For- nix, and the Pseudocele, the Constitution of the Velum, and the Su- perposition of the Prosencephal. The upper figure represents the mesal aspect of the right half of the schematic brain; the lower, a transection of both right aud left halves at the level indicated by the line A in the upper. In the lower figure the thickening of the black line representing the fornix may indicate the hippocamp, but strictly it should be corrugated, presenting an ectal furrow—the hippocampal fissure. The relations of the fornix to the rest of the parietes would also be more completely shown had the black line been interrupted a little laterad of the hippocamps. Defects.—The aula, the mesal part of the prosocele, is shown of equal size with the diacele, and on the same level; this is not the case, so far as the writer is aware, with any vertebrate in which the callosum and fornix attain dimensions such as are indicated in the figure (see Fig. 725) ; but so far as concerns the special objects of this figure, the above inconsistency may be ignored. Unlike most of the figures, the substantial nervous parietes are represented by the heavy black line, the pia and endyma by lighter ones. the cerebrum so as to constitute the velum (see Fig. 732); but since this figure does not represent the lapping of the prosencephal upon the diencephal at the s¢des, or the. 166 formation of the rima and paraplexus, the pia of the two segments is continued independently around each. C. The theoretical constitution of the diacelian roof by (1) the possible, though not always actual, continua- tion of the thicker nervous material at the sides, (2) the lining endyma, (3) the covering pia, one or both layers according to the closeness of their adhesion. D. The relations of the callosum, fornix, and pseudo- cele; the two former represent two lines of extended junction between the apposed mesal surfaces of the hemicerebrums; they are continuous at the splenium and likewise in man at the cephalic end; the space thus circumscribed like the hollow of a partition is the pseu- docele or “fifth ventricle”; it is really narrower, but the relations are as indicated. : E. The general constitution of the fornix is more fully described in § 197. § 151. Medicommissure (commissura media, s. grisea, s. cinerea, s. mollis, s. thalamic fusion).—Primarily sepa- rate, the apposed, mesal surfaces of the thalami unite (at about the fifth month of gestation according to Mihalko- vics), giving rise to what is commonly called the “ middle commissure ” (Figs. 670, 687, 707, and 709). It is in a di- rect line between the porta and the aqueduct, consider- ably nearer the former, and just dorsad of the aulix. The shorter, dorso-ventral, diameter, is 4-5 mm., the longer, cephalo-caudal, 6-7. It is relatively larger in all other mammals (¢.g., sheep, Fig. 688); it is present in turtles (Fig. 680) but absent in birds and other immammalia. Its functions are experimentally unknown, but in a man and a cat lacking the callosum, it was larger than usual. § 152. Anomalies of the Medicommissure.—lt is said to be sometimes double. Among sixty-six brains Wenzel found it absent inten. It is wanting in at least half a dozen of the (about two hundred) brains prepared or ex- amined by me with reference to it, amongst others in No. 8,334, Professor Oliver.* § 158. Azliz (sulcus of Monro; part of the interzonal sulcus?).—Most well-preserved brains present a move or less distinct furrow just ventrad of the medicommissure terminating cephalad at the porta (“foramen of Monro ”) and caudad near the postcommissure, sometimes in the mesocele and sometimes in the epiphyseal recess. It was figured and described by Reichert under the title “sul- cus Monroi,” for which I proposed (1884, e) the ee aulizx, a furrow (Figs. 675, 687).+ § 154. Epiphysis (conarium, pineal body or gland ; Figs. 675, 687, 707).—Excepting the lancelet (Branchiostoma) every vertebrate likewise has this apparently useless or vestigial diverticulum of the diacelian roof. Max Flesch believes that it is associated with the temperature ap- paratus, but the number of forms in which has been traced a connection between it and a rudimentary mesal eye is so great as apparently to warrant the view that it is the remnant of a primitive mesal organ of vision; see the papers of Béraneck (1892,) Heckscher, Ritter (1891), and Studniéka (1899); Ritter also describes the relation of the epiphysis to a blood sinus in Phrynosoma. § 155. Acerous (acervulus cerebr’).—The adult epiphy- sis frequently has embedded in follicular cavities calcare- ous particles known by the above names, and as “ brain- sand”; in the brain shown in Fig. 687, it was so abundant as to leave a considerable cavity when removed, but this unusual feature is not represented. * [venture to suggest that some of the reported cases may have been based upon inadequate evidence. Unless the brain is medi- sected while fresh, or prepared by the injection of a preservative into the arteries or the cavities, or both, the medicommissure commonly fails to be reached; its peculiar softness causes it to break easily; and the imperfect preservation of the adjacent thalamic surfaces might lead to the non-recognition of the slight elevation indicating its exist- ence. If the specimen is allowed to dry slightly, and is then held so that the light is reflected from the smooth endymal surface of the thal- amus, then the presence of the remnant of the commissure will be in- dicated by the absence of such reflection from an area corresponding with its usual location. There are few other parts of the brain where errors of observation are more likely to occur. + His and others have applied the name “sulcus Monroi”’ to an al- leged sulcus extending from the mesocele to or toward the optic recess, and have interpreted it asa portion of the interzonal sulcus (sulcus limitans ventriculorum) ; the grounds for dissent from this interpretation are stated in my papers 1896, d, and 1897, a. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, § 156. Peculiar Topographic Relations of the Epiphysis. —One of the striking results of the segmental overlapping and crowding is the embedding, as it were, of the epiph- ysis amongst four segments. Although directly con- nected with the thalami, the epiphysis leans caudad so as to rest upon the pregeminum; the cephalic aspect of the cerebellum rests upon the postgeminum and abuts against the epiphysis; finally the callosum, a cerebral commissure, has its splenial curvature upon the epiphy- sis. Between all these parts, of course, there are mem- EF KJ paracele pseudocele i hemiseptum + rostrum optic tract chiasma 4 : ‘ = optic nerve Fic. 711.—-Cephalic Aspect of the Terma (‘‘lamina terminalis”) and Adjacent Parts of a Young Child; 218. 1.5. 1, Torn margin of the pia on the chiasma; it has been removed from the adjacent sur- face; 2, gyrus subcallosus, continuous dorsad with the * peduncle of callosum.”’ Preparation.—The brain was exposed by removing the skull with nippers and scissors so as to avoid tearing the terma; the optic nerves were divided close to their foramina of exit. After harden- ing in alcohol, the parts adjacent to the terma were carved away ; the surface at either side is concave, following the general direction of the terma. The block was strengthened by a long (shawl) pin passed from side to side, and a common pin was pushed into the striatum at either side so as to project beyond the optic nerves and keep the latter from striking the sides of the vial. The removal of the pia from the terma was the most difficult part of the prepara- tion, and the utmost care did not prevent the tearing of a small slit - in the left side, which is ignored in the figure. branes and vessels, but if they are disregarded the epiph- ysis, a part of one segment, the diencephal, may be described as encompassed by three others, the mesen- cephal, the epencephal, and the prosencephal. With a brain hardened in its natural shape, a disc 2 cm. in di- ameter (e.g., a “nickel”) will cover parts of all four en- cephalic segments; see particularly specimens 385 and 2,268; in drawings, for the sake of clearness, the parts are sometimes represented as if less crowded; e.g., Figs. 672 and 687. § 157. Fig. 711 tllustrates: A The existence and com- pleteness of the terma (lamina terminalis or 1. cinerea), constituting the cephalic boundary of the mesal enceph- alic cavities; in the embryo it is actually the most ceph- alic part of the brain, but is later concealed by the pro- jecting hemicerebrums. B. The continuity of the terma with the chiasma, leading to the rupture of the former during the removal of the brain unless the optic nerves are early divided. C. The extreme thinness and delicacy of the terma which cannot be represented adequately in such a view, and is not always indicated in the medisections; Fig. 687. D. The existence of a somewhat thicker extension of the terma at each side, forming the cephalic boundary of the optic recess. E. The pair of slightly raised bands, commonly called the “ peduncles of the corpus callosum,” continuous ven- trad with the gyri subcallosi. F. The convexity of the entocelian surface of the caudatum (see also Fig. 707). G. The relation of the callosal rostrum to the hemi- septums, the lateral halves of the septum lucidum. H. The somewhat unusual thickness of the hemisep- tums in this specimen. VII. ProsencepHaL. —§ 158. Synonyms: Prosen- cephalon; telencephalon; forebrain; secondary forebrain; cerebrum; * pallium. The prosencephal is here regarded as composed of the cerebrum (cerebral hemispheres) less the olfactory bulbs and tracts, and the parts and cavities connecting them across the meson. See Table IL., p. 153. § 159. Peculiarities of the .Prosencephal.—From the other segments the prosencephal is distinguished by (a) the extraordinary range of variation among vertebrates, as seen in, ¢e.g., the hag (Fig. 791), the lamprey (Fig. 790), the salamander (Fig. 717), the frog (Fig. 685); the rabbit (Fig. 681); and cat (Fig. 682); (>) its preponderance in the human adult as contrasted with its primary insignificance (Fig. 676); (c) its (generally conceded) function as the organ of the “ mind.” § 160. Prosocele.—The prosencephalic cavity is pri- marily single and mesal, as indicated in the diagram, Fig. 674; it may remain so in cyclopean monsters (Fig. 712), and a nearly undivided adult cerebrum has been de- scribed by Turner (Fig. 7138). § 161. Mg. 712 illustrates: A. The increase of the pro- sencephalic vesicle in size and in the thickness of its parietes. As shown in Fig. 2 of the original paper, the floor and cephalic wall of the mesal region are 7 to 11 mm, thick, supposing the parts to be of natural size. B. The subordination of the lateral extensions to the mesal portion of the prosencephal; they do not, as in the normal brain, extend cephalad of the mesal boundary, but merely laterad, caudad, and to a certain extent ven- trad, so as partly to overlap the mesal portion. C. The partial formation of fissures, one of which may represent the Sylvian. D. As stated in the text, the prosencephalic cavity is single, z.e., not divided by constricted orifices (portas or Fic. 712.—Ventral Aspect of the Brain of a Cyclops, at Term. (From Cleland, Journal of Anatomy and Physiology, xii., Pl. xvii., Fig. 1.) The size of the specimen is not stated. The arachnoid has been removed from the mesal region, and from the left. The original paper contains a flgure of a medisection of the entire mass, a de- scription of some animal cyclopians, and a brief discussion of the nature of the malformation. “foramina of Monro”) into a mesal aulaand lateral para- celes. In this respect the cyclopean brain may be com- pared to the normal brain of “fishes” (Ganoids and Teleosts). E. The morphological instructiveness of many mal- formations. Goethe well said, “In her mistakes Nature often reveals her secrets”; indeed it is scarcely possible to imagine any encephalic malformation that may not * Cerebrum is sometimes employed loosely as embracing not only the olfactory region, but the thalami, quadrigeminum, and crura. 167 Brain. Brain, suggest, illustrate, or apparently contravene some mor- pnological idea.* § 162. ig. 713 illustrates: A. The possibility that an individual should reach maturity with a cerebrum so > yA \ a az are p: a | i i) ay il a) | % , >i Sung z ~ o Ww = REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. § 163. “ Third Ventricle.”.—The cavity commonly so- called really represents the mesal portions of the cavities of three segments; so much as lies between the thalami is the diacele; but the portion cephalad as far as the terma and fornix, although relatively small, pertains to the prosencephal and rhinence- phal; in some lower vertebrates (e.g., Chi- maera, my paper, 1877, a) it is much more extensive. § 164. Wig. 715 illustrates: A. The fun- damental morphological relation of each hemicerebrum as a lateral outgrowth, proc- ess, diverticulum, or “wing” of the mesal portion of the prosencephal. B. The non-formation or obliteration of rhinocele x ‘ 2 paracele mesocele Fig. 714.—Diagram of the Prosocele and Adjoining Cavities. all the fissural corrugations and inequal- ities, excepting the Sylvian, which is a mere shallow depression extending obliquely dorso-caudad along the lateral aspect of each hemicerebrum. C. The enormous size of the porta, yet F1G. 713.—Dorsal Aspect of an Imperfectly Divided Cerebrum. X .7. (From Turn- er, Journal of Anatomy and Physiology, xii., January, 1878, pp. 241-253.) af, Precentral gyre; ap, postcentral gyre; if, subfrontal gyre; mf, medifrontal gyre; O, occipital lobe; pe, “‘ convolution of parietal eminence ’’; PO, occipital fissure ; pp, ‘ postero-parietal convolution ’’; Ry central fissure ; sf, superfrontal gyre; I, II, mesal transverse gyres, nearly at the level of the adjoining hemicere- brum ; III, sloping cortical surface ; IV, mesal gyres at a lower level than I and II. Preparation.—The brain was taken from an epileptic imbecile, male, forty- eight years of age, 146.7 em. (four feet ten inches) high, and weighing 55.7 kgm. (123 pounds). The entire brain w eighed 1,111.7 gm. (39.25 ounces), of which the cerebrum constituted 978 gm. (34.5 ounces). Most unfortunately this rare, if not actually unique, specimen was simply placed in alcohol, which was not changed ; hence the base was ill-preserved, and the ental features, although described in some detail by Turner, cannot be fully understood. A transection disclosed a single mesal, cerebral cavity, about 5 cm. wide, the floor of which is said to have been “‘ formed of the upper surfaces of the corpora striata and optic thalami, which bodies were related to each other and to the tenia semicireularis as in anormal brain ’’; yet ‘the third ventricle opened freely into the cerebral cavity along the middle of the floor.”” It is to be hoped that figures and more detailed descriptions may be published respecting the structure of this remarkable specimen. A good abstract of the original paper is given in Brain, i., 183-134, April, 1878. the maintenance of its complete circum- scription. D. The tenuity of most of the parietes; in the occipital region they are no thicker than a sheet of ordinary paper, and are really exaggerated by the two ink lines and inter- vening space. E. The extraordinary distinctness of the mass named caudatum, of which another view is given in Fig. 722. F. The peculiar form and relations of the rounded mass intervening between the cau- datum and the lateral wall, and which may represent the lenticula. G. The non-appearance of the thalamus in the floor of the paracele. H. Upon the whole, the retention, sub- nearly undivided. Substantially, the prosencephalic vesicle has not only increased in size and in parietal thickness, with but slight differentiation into a mesal and lateral mass, but the entire mass has developed fissures and gyres after the usual pattern, in general, ex- cepting that certain gyres cross the meson; @ prvort, in- deed, it is not clear why such a brain should not be effi- cient for mental as well as bodily manifestations. * On this account it is to be the more regretted that so few such specimens are adequately preserved, examined, figured, described, and explained; indeed, no case is known to me in which the best possible use has been made of the opportunity ; it is particularly de- sirable that, when malformation is suspected, the brain be thoroughly hardened by alinjection (injection of alcohol) of both the arteries and the cavities. 168 stantially, of a condition of the cerebrum comparable with the normal state at a much earlier period of development; it is, as it were, an ex- pansion of such a cerebrum as exists at twelve weeks (see Fig. 667). § 165. Paraceles (“lateral ventricles ”).—But the lateral extensions speedily become so considerable as to warrant the specification of a mesal portion, awla, a pair of para- celes (“lateral ventricles”), and constricted communica- tions, the portas (“foramina of Monro”) (see Figs. 678, 684, 690, 723).* § 166. Cornua.—EKach paracele is primarily sub- spherical and simple as in Figs. 667 and 678; in hydro- * If the rhinencephal is regarded as a segment, the aula and portas must be regarded as pertaining in part to it. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. cephalus this condition may be maintained approxi- mately till birth (Fig. 715). But normally, by the unequal thickening of the parietes, by their encroachment upon the cavity, and perhaps by the further extension of the latter, there are somewhat vaguely demarcated a central cella, continuous through the porta with the aula, and hippocamp (?) paraplexus | ) 1 ' ! ! "4 VBA Brain, Brain, three “horns,” a ventral medicornu, a cephalic precornu, and a caudal postcornu. The last exists only in Primates (man, apes, monkeys, and lemurs) and a few other mam- mals, mostly members of the seal family. The cornua appear in Figs. 684, 720, 726, 785, and 736. § 167. Fig. 716 illustrates: A. The great extent of the paraceles at this period, relatively to the entire cere- brum, and to the mesal part of the prosocele, the aula. B. The less difference in the thickness of the parietes than in the adult. C. The distinct collocation of the hippocamp with the hippocampal fissure. D. The topographical relation of the Sylvian fossa, the first stage of the Sylvian fissure, to the caudatum. E. The extension of the postcornu farther caudad of the aula than the precornu extends cephalad. F. The absence of the insula at this period. G. The outgrowing margin of the operculum. H. The depth and peculiar shape of the lambdoidal fissure (see Fig. 750). § 168. The porta, in a little modified condition, may be seen in the large salamander, Oryptobranchus. When the lateral wall of the alinjected hemicerebrum is removed (Fig. 717), the paracele is seen to communicate with a mesal space (aula) and thereby with its opposite and with the diacele, through a considerable orifice, the porta. Its caudal end is narrower than the cephalic, but it is seen to be completely circumscribed by ordinary nervous walls. § 169. Hig. 717 tllustrates: A. The simple condition of the prosencephal in this amphibian; each hemicere- brum is an elliptical, thin-walled sac, the cavity of which, the paracele, communicates through a porta with the aula and so with the diacele. B. The large size of the porta, its length equalling caudatum Sylvian fossa 1 :. precornu . caudatum 5 > genu precornu Fig. 715.—The Left Paracele (Lateral Ventricle) of a - pseudocele Female New-Born, (7 Months?) Hydrocephalus. E No. 2,131. X 1. 1, One of several slight undulations - hemiseptum of the ental surface in the frontal region; 2, slight pit, probably artificial ; 3, cephalic margin of a break, apparently natural, in the mesal parietes; the ven- - fornix tral margin of this break is indicated by 7, and the corresponding caudal margin projects slightly mesad just caudad of the line ; it may be supposed that this interruption of the mesal wall represents the loca- orta tion of the callosum that might have been formed; 4, Pp 5, slight elevations as yet undetermined; 6, dis- - aula tinct though rounded ridge corresponding to the 4 shallow Sylvian fissure, the only recognizable fis- tenia sure; 7 (see 3); 8, occipital end of the hemicere- ambri brum, projecting slightly beyond the cut surface ; Se 9, membranous portion of the parietes (perhaps an dentate gyre attenuated tenia) through which the thalamus e shows. . Preparation.—The child was supposed by the hippocamp physician and parents to be seven months advanced ; it breathed a few times; the weight was 1,618 gm. diacele The neck and scalp were swollen, but the head was not unusually large. Normal salt solution was :n- , jected into the umbilical vein and escaped, with supracommissure blood, from the jugular. Then half a litre of ninety-per-cent. alcohol was injected, the jugular postcornu being closed. The scalp, calva, and dura were re- moved, and the head supported in brine while the ~ Jambdoidal f brain was extracted; in spite of care there was Bi ‘ ; : some separation of the hemicerebrums at the me- medicornu : 2 thalamus : _ y G son. The contained liquid was allowed to escape, paraplexus epiphysis the brain placed in ninety-per-cent. alcohol, and the hemicerebrums inflated to their natural size; they were then covered with a thin layer of absor- bent cotton to keep them submerged. The alcohol was changed twice at intervals of two days, and on the fifth the various sections were made under al- cohol. The mass supposed to represent the caudatum was extremely dense. The pia was firm, and in parts more substantial than the attenuated parietes. The condition of the diencephal was not fully de- terminable;: the mesocele seemed to be wholly oc- cluded, which would account for the condition of the cerebrum. Th? entire specimen needs further study and comparison with similar cases. plexus. Fic. 716.—Ventral Exposure of the Prosocele of a Fetus about 24 cm. Long, and Esti- mated to be Twenty Weeks Old; 499. X 1.5. ( and the caudatum; 2, thin extension of the paraplexus into the postcornu; soon after the preparation was made this became detached and was lest ; another speci- men must be depended upon to show whether or not such extension exists, and in what way it is disposed of in case it be deciduous; 3, hippocampal fissure ; 4, dia- 1, Line of continuity of the thalamus Preparation.—The brain was hardened in place by arterial alinjection; the scalp and calva were removed piecemeal, and the dorsal part of the cerebrum re- moved by one sweep of the knife under alcohol. ) side as indicated by the heavy line (endyma) enclosing the lighter area. The left caudatum was removed so as to expose the paracele more completely on that side and make the figure comparable with that of the cat (Fig. 686). The parapiexus was cut at each 169 Brain, Brain, supraplexus diencephal © E o =| Ee = 1S) x = ° | : 2 porta Fig. 717.—Prosencephal of Cryptobranchus (a Salamander), the Left Paracele Exposed; 291. X 6. Preparation.—The fresh brain, while supported by the skull, was alinjected by lifting the metatela (membranous roof of the “fourth ventricle ’’) and pointing the cannula at the broad epicele ; the entire brain at once swelled somewhat, and the thinness of the walls caused it to harden almost immediately ; the lateral wall of the left hemicerebrum was then sliced off, and REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. § 171. The exact conditions and relations of the rima, para- plexus, tenia, fimbria, and thal- amus near the porta have not been as yet clearly made out. Preparations should be made with special reference to their elucidation, and figures upon a very large scale. Excepting the metapore (“foramen of Magen- die”) no part of the brain in- volves so many and so important morphological questions; see the difficulties and doubts admitted under Fig. 719. § 172. Mg. 719 tllustrates: A. The size, form, and direction of the porta from the mesal as- pect. B. The complete circumscrip- tion of the porta, dorsad, by the reflection of the endyma upon the intruded plexus (Fig, 668). C. The greater length of that part of the prosoplexus which hangs in the porta (portiplexus) than of that which hangs in the the paraplexus cut off where it projected from the aula through the porta into the paracele. about one-third that of the entire cerebrum; its cephalo- caudal direction as compared with that of mammals, birds, and reptiles, where—especially in mammals—it is dorso-ventral. C. The absence of a rima; the prosoplexus enters the aula from the supraplexus and sends a prolongation through either porta into the paracele, where it hangs freely. § 170. The porta is com- pletely circumscribed, so that a cast has a definite outline, viz., that of an elongated el- lipse, its longer diameter, 4-6 mm., its shorter 1-8 (see Figs. 718, 724). The portal bound- aries are as follows: caudal, the thalamus (perhaps the te- —~ paracele ---- right porta i diacele Fig. 718.—Cast of Aula, Portas, and Part of Diacele. X 1.5. The main object of the figure is to demonstrate the complete circumscription of the porta, and its independence of the rima($ 177). The material used was a mixture of wax and gutta percha. The mesal ridge which represents the aulic recess is just dorsad of the precommissure (Fig. 724). The fig- ure should have been so placed as to make this ridge nearly vertical. nia); cephalic, the column of the fornix; ventral, the junc- tion of the thalamus and col- umn; dorsal, the endyma re- flected from the thalamus and column upon the intruded por- tiplexus (Fig. 668). So long as this endyma retains its ad- hesions, so long the circum- scription of the porta is com- plete. 170 precommissure = precerebral a. aula (auliplexus). D. The constitution of the ve- lum as a fold of pia, with blood-vessels intervening; one lamina of the fold belongs to the fornix, and the other to the thalamus, or rather to the diatela or primitive dia- celian roof (Fig. 710). E. The relation of the ventral end of the porta to the aulix (“sulcus of Monro”). pia fornix (a) endyma habena velum pia termatic a. diaterma - Fic. 719.—The Right Porta and Adjacent Parts, Seen Obliquely from the Caudal Side; 385. x 4. The lateral aspect of the left porta of the same brain is shown in Fig. 720, under which the mode of preparation is described. 1, Dotted line from the ventral end of the porta to the ventral margin of the precommissure, and assumed to demarcate the diacele from the aula; 2, part of the mesal sur- face of the hemiseptum, unusual and not fully understood (see § 172, H). Defects.—The area marked 2 is not a cut surface as its plainness would indicate ; it was shaded lightly in the drawing, but became blank in the engraving. The extent of the pseudocele and the length of the copula are so unusual as to be anomalous; these peculiarities, however, do not materially affect the porta, which is the important feature of the figure. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. F. The thinness of the commissure of the fornix, a. G. The unusual length of the copula connecting the callosal rostrum with the prosoterma. H. The unusual extension of the pseudocele and of its lateral parietes, the hemiseptums; it is uncertain how far this existed naturally, or was produced by the pressure of alinjection. § 173. Fig. 720 illustrates: A. The location and general form of the paracele; unfortunately, however, the post- “J [eayuao bo] =) a E 3 ~dentate gyre ~ ~ealcarine fissure ~>+~_fimbria “~~ hippocamp Sa . ~~ _medicornu ~~ collateral fissure ~~- subtemporal fissure Fig. 731.—Transection of the Right Hemicerebrum of an Adult Hydrocephalus ; 747. 1, Ventral curvature of splenium ; 2. groove at cephalic margin of splenium ; 38, mesal furrow of fornix (the line does not quite reach it). the lines from hippocampal fissure and dentate gyre is the continuation of the callosal fissure, separated from the hippocampal by a fiattened area of cortex. deep fissure opposite the word insula is the central. Preparation.—This represents the cephalic aspect of the caudal part of the hemicerebrum, the mesal aspect of which is shown in Fig. 743. was along the oblique line d-v on that figure. The furrow between The The transection So much of the thalamus as was meets the pia covering the dorsal aspect of the thalamus, and is reflected with it dorsad and then mesad toward the opposite side. included was cut away, together with some of the adjoining prosencephalic mass, capsula, lenticula, and perhaps claustrum, leaving little more than the cortex of the insula at that Qoint. ’ Defects.—The shading does not discriminate sufficiently between the natural and artificial surfaces, but the former are curved while the latter are straight and Instead of passing horizontally across the in- terval between the thalami, however, the en- dyma is deflected over the two vascular plex- uses (folds of pia or vessels therefrom) which hang in the diacele. The habena and its sulcus, more accurately, perhaps, the latter, constitute the boundary line between the mesal, entocelian, endymal surface of the thalamus, and the dorsal, ectocelian, and pial surface, which extends dorso-laterad. Between the dorsal surface of the thalamus and the ventral surface of the fornix (including, of course, the fimbria), the pia is freely separable, and appears to con- sist of butasingle layer; but laterad it is traceable to the paraplexus, and it is almost inconceivable that a plexus should be formed of a single layer of pia as a free edge covered by endyma. When, however, this fornico-thal- amic pia is traced mesad, it is found to separate into two layers, a dorsal, belonging to the fornix, a ventral, con- stituting part of the diacelian roof (diatela) with a pair of arteries, a pair of veins, and numerous smaller vessels in the intervening space. The ventral layer is not separable (in man) from the diacelian endyma, but the dorsal not only may be detached from the fornix in an alcoholic specimen, as may the pia from most of the sur- faces which it covers, but here, excepting at the margins, the disjunction was almost spontaneous, and there is a distinct space (8) between it and the commissure, bounded at the sides by the thicker (hippocampal) constituents of the fornix. This double curtain of pia is the velum bounded by sharp lines. hemiseptum is added by dotted lines. The alba and cinerea are not distinguished. The left as along the entire margin of the paraplexus (see Figs. 710 and 737). Corresponding with the margin of the fimbria, the dorsal surface of the thalamus presents a shallow groove, the fim- brial sulcus (“sulcus choroideus,” Fig. 707); laterad from this the surface is nearly regular, and overlaid partly by the paraplexus and a membrane apparently endyma only, and partly by the thin but more substantial lamina (tenia ?) already described as an extension of the caudatum. The entire dorso-mesal surface of the thalamus, instead of being homogeneous, as it has been sometimes figured and described, may be divided, first and most sharply into a mesal, or entocelian, and a dorsal, or ectocelian, portion, the boundary between the two being the habena and its sulcus. The dorsal surface itself presents a two- fold division into a subfornical (B) and a parafornical (C and D), separated by the fimbrial or choroid sulcus. Finally, the parafornical area is covered partly by the paratela and plexus and partly by the tenia, and may thus be distinguished as subparatelar (C) and subtenial (D), there being occasionally a furrow, the tenial sulcus, between them. The desirability of discriminating be- tween these areas will appear in connection.with Fig. 7338, where certain different, and perhaps anomalous, con- ditions are described. 175 Brain. Brain, So far as this preparation is concerned, there is abso- lutely no adhesion of endyma to any part of the thalamus dorso-laterad of the habenal sulcus; on the contrary, the endyma is traceable in uninterrupted continuity about caudatum pia habena A medicommissure em Fic. 732.—Transection, Partly Schematic, of the Fornix and Adjacent Parts at a Level Cor- wt intercerebral f. arachnoid 4 i REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. There are, however, differences between these and other preparations which are not easy to explain, except- ing upon the general supposition that a region in which the conditions are nearly peculiar to the human brain might naturally be expected to present individual peculiarities and even anom- alies. § 190. There seems to be considerable variation in the details of the parts in- volved in the apparent representation of the thalamus within the paracele; this is perhaps to be expected, BEE allosal £, since the conditions that have made the usual state- endyma ments possible constitute a great and perhaps peculiar paracele modification of the primitive and typical relations—indeed, tenia almost a malformation. paraplexus It is hoped that the fore- fimbria going descriptions and fig- pseudocele ures may at least serve to hemiseptum induce anatomists to investi- gate the subject in all its commissure bearings. § 191. In What Sense does the Thalamus Form Part of the Floor of the Paracele (Lateral Ventricle)?—So widespread and so deeply rooted seems diatels to be the notion that the thalamus con- ‘dinplexta stitutes a part of the paracelian floor in the same sense as do the caudatum and Aine the hippocamp, that, much as I would prefer to avoid the critical attitude, I am induced to comment upon the cur- rent representations of this region. Admitting, for the sake of occupying responding with the Interval between the Medicommissure and the Postcommissure ; 1,824. % 2.5. 1, Fimbrial sulcus (*‘suleus choroideus”’) ; 2, tenial sulcus (in some specimens) ; 3, tenial vein; 4, precerebral arteries; 5, velar veins; 6, velar arteries; 7, habenal sulcus; 8, interval (natural ?) between the velum and the commissure of the fornix; 9, lateral part of the fornix (hemifornix) ; A, mesal, endymal surface of thala- mus; B, ©, D, zones of its dorsal surface; B, subfornical; C, subendymal; D, subte- nial. Between the left paraplexus and the tenia the membranous floor of the paracele is the paratela. The figure represents the caudal surface of the transection ; the observer is look- ing cephalad, and his right coincides with the right of the specimen and the figure; the two sides are substantially identical, but less is shown upon the right; the meson of the figure, the anatomical middle of the various parts and cavities represented, is dextrad of the middle of the area covered by the figure. Throughout the figure the cavities are shaded and the blank areas represent transected surfaces. The arachnoid is represented by a narrow, straight line, the pia by a corrugated line, and the endyma by a heavy line; the endyma is made to adhere closely to the entocelian surfaces, but the pia and arachnoid are separated slightly from the parts which they cover. Preparation.—See Fig. 744, representing another transection of the same brain. The celian parietes were thoroughly hardened before the brain was removed from the skull, and the membranes and plexuses have retained their connections notwithstand- ing much handling and considerable transportation. There is some distortion and dislocation of the loosely connected parts about the fornix, but it has been possible to clear up most of the doubtful points by comparison of the two sides and with adjoin- ing sections. So far as respects the exclusion of the dorsal surface of the thalamus from the paracele, the preparation affords unequivocal evidence. Defects.—As in several other figures representing transections of plexuses, it has been assumed that a plexus consists of a fold of pia covered by endyma; for present purposes it matters not whether there is a complete fold of the pia, or merely an ex- tension of vascular loops. The ventral lamina of the velum is made too low. The medicommissure, the dorsal margin of which is included at the ventral side of the fig- ure, did not actually appear in this section, which was just caudad of it, but is intro- duced as a readily recognized landmark. The indusium is not shown (§ 217). common ground, that a certain area of the dorsal surface of the human thala- mus is covered by endyma; that it is continuous with the caudatum, and that therefore, like that body, it enters into the composition of the paracelian floor; none will deny that an adjoining area of this same dorsal surface is as dis- tinctly covered by pia; that it is con- tinuous with the optic lobes (gemina), and Jike them wholly excluded from the encephalic cavity. To represent the entire dorsal aspect of the thalamus as a smooth, unbroken surface is practically to affirm one of two things: either the whole is pial or ectocelian, which would be in contra- vention of the obvious facts; or else the whole is endymal or entocelian, which would involve not only the gemina but the cerebellum and oblongata, a mani- fest reductio ad absurdum.* § 192. The Collicult.—This: collective term is applied to the rounded emi- nences and ridges which project into the paraceles (“lateral ventricles”) from each paracele, over, in turn, the ventral surface of the callosum, the caudatum, the tenia, the paraplexus, the fimbria, the thicker portion of the fornix, and the hemi- septum, back again to the callosum. § 188. With some specimens the interval between the paraplexus and the caudatum seems to be occupied by a somewhat substantial lamina, separable from the thala- mus, continuous with the caudatum, and perhaps merely a special development of the tenia, but requiring further investigation (Fig. 7383). § 189. The point illustrated upon Fig. 733 is the con- tinuity of the paracelian floor from hippocamp to cau- datum without the intrusion of the thalamus. This figure is to be studied in connection with the transection (Fig. 732), and the dorsal view of the floor in Fig. 735. 176 their parietes. They are the caudatum (caput and cau- da), hippocamp (“hippocampus major”), calear (“hippo- campus minor”), collateral eminence, and occipital emi- nence. Excepting perhaps the first, each of these * For a fuller discussion of the relations of the thalamus to the para- cele, and for commentaries on the misrepresentations in standard works, see the first edition of the REFERENCE HANDBOOK, viii., 144- 147, and ix., 107, and my papers, 1888, a, and 1889, d. The delicacy of the membranes, the readiness with which they are detached along a ripa, the rough handling to which brains are commonly subjected during the ordinary processes of removal and examination, the slight degree in which preservatives can reach the parts in question when the entire organ is merely immersed as usual, and, finally, the fact that some agents, excellent for microscopic purposes, do not well pre- serve the endymal attachments—all these conditions conspire to bring it about that the endyma across the wide rima should be torn, and the dorsal surface of the thalamus protrude through the rent. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, represents a corrugation of the entire thickness of the parietes, the ental elevation (colliculus) being collocated with an ectal depression (fissure); this collocation is in- dicated in the list of total fissures, § 258. § 193. The Callosal Hminence.—Besides the colliculi named in § 192, all of which are more or less distinct in at least some adult brains, there is one which is perfectly obvious in some fetuses (Fig. 734, 1), and which, from its apparent collocation with the callosal fissure (Fig. 742), may be called, provisionally, the callosal eminence. It, the hippocamp, and the occipital eminence form an ir- regular triradiation. Its commencement and disappear- ance require further observation, but its unbroken con- tinuity with the hippocamp confirms the idea that the callosal and hippocampal fissures are essentially parts of one, merely deflected by the splenium of the adult. § 194. The relative size of the colliculi is not the same in the adult asin the fetus. This is clear from the com- parison of Fig. 734 with Figs. 744 and 761. The callosal eminence may disappear wholly; the occipital is seldom recognized (Fig. 744); the collateral is certainly less prominent in the adult than in the fetus (Fig. 734). § 195. Hig. 734 tllustrates: A. The contiguity of the margins of the fimbria and the tenia (the edge of the caudatum) with just room for the entrance of the para- plexus, and the concomitant complete exclusion of the thalamus from the paracelian floor (compare Figs. 732 and 788). B. The existence of an ental ridge (1) at this period, continuous and corresponding with the hippocampal and callosal fissures; whether it extends still farther cepha- lad, as in Fig. 742, cannot be ascertained from this speci- men. C. The branching off of a ridge corresponding ap- ‘parently to the occipital fissure, and representing the adult occipital eminence. : fmbria—__N& paraplexus, tenia thalamus caudatum paraplexus velum fimbria: hippocamp, medicornu. t ieee D. The existence of two intermediate ridges, perhaps prefiguring the calcar and collateral eminence. fossa Sylviana paraplexus caudatum i fimbria \ _- occipital eminence _-occipital Te _calcar ~=COllateral eminence j~—-~— collateral f. ~>s.~hippocamp ~s...medicornu Fia. 734.—Left Hemicerebrum, Laid Open, of a Fetus Weighing 88 gm. (3 ounces), Measuring 15 cm. from Heel to Bregma, and Esti- mated at Fourteen Weeks; 2,083. 1.5. Preparation.—The fetus was received fresh; the head was cut off and pinned by the neck to a cork loaded with sheet lead; a shaw] pin was inserted as a handle at one side of the head. A slit was made through the scalp at the lateral angle of the prefontanel, and the guarded cannula adjusted so that ninety-five-per-cent. alco- hol should enter the paracele gently, with opportunity for egress at the side of the cannula. After six hours the alinjection was discon- tinued, but the specimen remained in alcohol for two days, when the scalp was removed and the specimen placed in ten-per-cent. nitric acid. After five hours the calva was so far decalcified that it could be cut away with the scalpel and scissors without jarring the very delicate brain. The left hemicerebrum was then exposed as indicated, and the nape of the neck removed to expose the collateral fissure. Upon a larger scale some of, the, points would have ap- peared more clearly. 3 intercerebral f. callosal f. paraplexus fimbria hippocamp 5 epiphysis 6 mesocele —.tegmentum -—crusta Fic. 733.—Dissection, Partly Schematic, of the Floor of the Left Paracele (‘* Lateral Ventricle’’), Caudal Aspect; 2,345 and 2,347, 1.5. Com- pare in part with Fig. 706. 4, Lateral sulcus of the mesencephal; 3, oculomotor nerve; 5, line of somewhat sudden deflection of the splenial fibres caudad into the occipital lobe ; 6, large vein; 7, fimbrial sulcus; 8, angle between the fimbria and the hippocamp ; 9, hippocampal fissure. Preparation.—The arteries were injected with the red glue mixture, and the cavities with alcohol. When hardened, a thick slice was taken by one transection at about the middle of the length of the callosum and another at the splenium, just shaving off the tip of the epiphysis. The original transection of the brain stem between the mesencephal and epencephal was modified by carrying two sections cephalo-mesad, meeting at the level of the valvula. On the right of the cerebrum the parts were left undisturbed, excepting that the paraplexus was raised so as to expose the floor of the cavity. On the left, a thin slice of the hemicerebrum is left attached to its opposite by the pia. In order to expose the paracelian floor as completely as possible from this point of view, the sections had to be made in many directions. The paraplexus was trimmed down for a certain distance; then a wedge-shaped piece was cut from the thick caudal wall, hippocamp, etc., including part of the thinner floor, fimbria: this exposed the velum, the double fold of pia between the dorsal surface of the mes- and diencephal and the ventral surface of the fornix. Very cautiously then the two parallel incisions were carried across the floor to and into the caudatum constituting the lateral wall; the strip so enclosed was then lifted; it included (1) a piece of the fimbria; (2) the disconnected part of the paraplexus; (3) a strip of the thin lamina intervening between the plexus and the caudatum; in 2,347 all these were found separable from the dorsal surface of the thalamus, substantially as in the transection, Fig. 732; in 2,345 there were com- plications which should form the subject of monographic consideration. See § 189. Defects.—The defects of the figure are due mainly to the attempt to combine the appearances presented by two different preparations. Vou. Il.—12 WT Breil REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, intercerebral f. GENU of the CALLOSUM ARACHNOID CAPUT of the CAUDATUM —— PSEUDOCELE —~HEMISEPTUM CAUDA Of CAUDATUM fy —FIMBRIA Sylvian f.- supertemporal f. ote POSTCORNU : e Fig. 735.—The Paraceles (‘‘ Lateral Ventricles’’) of an Adult Male, Exposed from the Dorsal Side; 2,867. 1.2. Preparation.—The entire body (an emaciated consumptive, weighing only 37.71 kgm., 83.25 pounds) was alinjected through the fem- oral artery. Eight and one-half litres were introduced on the first day, and some escaped from the mouth. On the second day, and again on the fourth, another litre was injected. On the fifth day there was injected a litre of Pansch-Gage starch mixture (see article Brain : Methods, etc.). When the brain was removed, on the eighth day, the only odor was of the alcohol. The substance had already hardened somewhat and the arteries were well filled, notwithstanding some of the mass had extravasated into the thorax. The brain was tran- sected through the mesencephal (see Brain: Methods), and the paraceles exposed by removing the dorsal portion of the cerebrum in thick slices down to the level of the callosum ; then in thinner slices and wedge-shaped pieces till the desired condition was reached. On the left the medicornu was exposed into the part extending cephalad ; the terminal portion extending also mesad could not be shown with- out cutting away an undesirably large mass. On the left also the occipital lobe was cut to a slightly lower level than on the right; hence, on the right appears the dorsal slope of the calear, while on the left the plane of section coincides with the line of its greatest elevation, and the width of the postcornu is correspondingly reduced. To lessen the width of the figure a part of the lateral convexity was removed by dorso-ventral incisions between 3 and 4, and 4 and 5, so the line representing the pia ceases at 3and 5. Finally, the left paraplexus was trimmed off quite closely. (For the rest of this explanation, see at bottom of page 179.) 178 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. § 196. Fig. 735 illustrates: A. The general relation of the paraceles (lateral ventricles) to the cerebrum; al- though relatively much smaller than in the fetus, they are absolutely extensive; here their natural extent has been maintained by the injection of alcohol; when ex- amined in a fresh brain or in one hardened in the usual way their walls are often found nearly in contact.* Bb. The termina] dilatation and squareness of the post- cornu, as contrasted with the pointed form which usually exists in brains not prepared by filling the cavities; sometimes, indeed, there has been doubt as to the extent of the postcornu, as admitted by Huxley, Zoél. Soc. Proceedings, 1861, p. 250; in Krause’s “ Handbuch” (1880), Fig. 479, the postcornua are merely linear. C. The great thickness of most of the parietes as com- pared with their thinness in the fetus, Fig. 667. D. The retention of the fetal tenuity of a portion of the mesal wall, viz., the hemiseptum (halves of the septum lucidum). E. The considerable length and width of the human pseudocele (fifth ventricle); so far as I have observed it is wider than in any other animal; in Fig. 726 (of the sheep) it is unnaturally wide. F. The relation of the cortex (cerebral ectocinerea) to the medulla (alba), as an ectal layer following the fissural indentations. G. The relation of the insula to the Sylvian fissure; the former is a typical subgyre, the latter is a typical superfissure. H. The relation of the claustrum to the insular cortex ectad and the lenticula entad (see also Fig. 782). I. The constitution of the caudatum by two regions, a larger cephalic, the caput, and the cauda, narrow, and following the curve of the medicornu. J. The junction of the occipital and calcarine fissures so as to constitute as it were a single bifurcate fissure. K. The size and distinctness of the collateral eminence, an ental elevation or colliculus, corresponding to the col- lateral fissure upon the ventro-mesal aspect of the cere- brum. L. The existence, on the left, of an elevation, the oc- cipital eminence, corresponding with the occipital fissure. This colliculus is distinct in the fetus (Figs. 734 and 761), and in some adults (Fig. 744) is better marked than in this specimen. M. The location of the portas (foramina of Monro), and their visibility in a direct dorsal view of the para- celes; by reference to Figs. 720 and 724, it will be seen that each porta opens into the corresponding paracele obliquely, looking laterad, cephalad, and also dorsad; hence it is visible from three different directions at right angles with one another. N. The distance between the two portas. Deducting the slight length of the passages themselves, this dis- tance represents the width of the aula, the mesal division of the prosocele, which is commonly reckoned as merely the cephalic part of the “third ventricle.” O. The continuity of the hemiseptum, a part of the -mesal wall of the paracele,.with the fimbria,.a part of. its floor; indeed, their topographical relations may be illus- trated by bending a sheet of paper or metal, and holding *The paper of E. A. Spitzka (1900) will contain an account of the topographic relations of the paraceles to the cerebral surfaces. Brain, Brain, it so that one portion is vertical and the other nearly horizontal; the former will represent the hemiseptum, the latter the fimbria. P. The narrowness of the human fornix as measured by the distance between the lateral margins of the two fimbrias in their horizontal portions: compare the sheep, Fig. 726. It is true the word fornix does not occur on the figure; but, as discussed in § 197, the fornix is constituted by the two hippocamps, with their fimbrias, united at the meson by the commissure (Fig. 732); in this dissection the commissure is invisible, being upon a lower plane, so the fornix, as a whole, cannot be indicated. Q. The smallness of the paraplexus as compared with its fetal condition, Figs. 667 and 747. R. The formation of the free margin of the paraplexus by the medicornual vein, considerable in size and more or less contorted, by which the blood of the plexus is re- turned to the velar vein. 8. The considerable width of the attached portion of the paraplexus. This appears on the left side where the plexus has been trimmed quite closely. The rima is the line of apparent interruption of the parietes for the in- trusion of the paraplexus, and is unusually wide in this specimen. T. The completeness of endymal continuity and celian circumscription. These terms have been discussed in $$ 63-66, as exemplified upon the mesal aspect of the brain, Fig. 687. There only the mesal cavities are visible. In the present figure (aside from the pseudocele, which is not a true member of the series) there appear only the great lateral cavities of the prosencephal. The continu- ity of the endyma is represented by the uninterrupted heavy line surrounding either paracele. Likewise is the endyma a continuous sheet upon the sides and floor of this cavity. At the margins of therima it may be traced as a smooth surface upon the intruded paraplexus, and its cut edges are represented on the left in this figure. I am aware that several authors claim or admit the exist- ence of orifices along the medicornu whereby the neuro- lymph may escape therefrom into the adjacent subarach- noid space; but I am compelled, at present, to regard these as artifacts, like the half-dozen ruptures of the Se near the porta in the preparation shown in Fig. 21. U. The apparent entrance of the thalamus into the composition of the floor of the paracele. This condition is presented on the left side; on the right it is hidden by the overlapping paraplexus. : § 197. Fornix is a collective noun, a comprehensive name applied to a congeries of parts, each of which has its own name, and all of which, with a single exception, may exist in lower vertebrates and in man or other mam- mals, in certain anomalies, without the formation of the fornix as a whole. § 198. Columns of the Forniz.—In each hemicerebrum there is a bundle of fibres ascending from the albicans and thalamus, passing just caudad of the precommissure, forming the cephalic boundary of the porta, diverging presently from its opposite, pursuing a curved direction along the floor of the medicornu and ending in the tem- poral lobe; in the aulic region, where it is most compact and exposed, this is commonly called an “anterior pillar of the fornix”; see Fig. 739. § 199. Hippocamp (“hippocampus major”).—In each (Fig. 735.)—1, Cut surface, extending meso-ventro-cephalad ; 2, cut surface of the genu, the cephalic curvature of the callosum ; part of its nat- ural, pial surface lies just cephalad ; the transverse lines on the areas 2 and 9 are introduced merely to indicate the direction of the callosal fibres, not as representations of microscopic structure ; 3, point of disappearance of the pia as a result of cutting away part of the lateral convexity of the cerebrum ; 4, meeting-place of the two oblique cut surfaces caused by the exposure of the medicornu ; 5, point of reap- pearance of the pia, which was interrupted at 3; 6, is an area just caudad of the left calcarine fissure ; 7, the occipital fissure ; 8, the occip- ital eminence (see under Defects) ; 9, oblique cut surface of the splenium, of which a part of the natural surface is shown just caudad ; 10, the cut edge of the paratela covering the thalamus; from 10 a line should pass mesad to the narrow area between the two lines. | Defects.—The alcohol had so bleached the cinerea as to render the recognition of its outlines somewhat difficult, so the width of the cortical zone is only approximately accurate. The absence of shading upon the larger part of the surface would imply that it is all upon one level; really, however, the highest part corresponds nearly with the length of the exposed portion of the right caudatum, and from that level there are gentle slopes cephalad, cau- dad, and laterad. The cut edges of the hemiseptums are also at a lower level than the adjacent lateral parietes. Not all of the arteries are represented. The occipital eminence (8) is indistinct upon the right and made too small upon the left. The cut edge of the paratela (10) is made too thick and the relations of parts are indistinct (see § 191). On the left, near the word fimbria, is a defective patch of shading du to a blemish in the paper. ; The arachnoid is represented distinct from the pia at only two places, viz., on the right, near the cephalic end, where the former crosses the wide mouth of a fissure, while the latter dips into it as a fold, and at the collosal fissures, just caudad of the splenium. 179 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. hemicerebrum there is a corrugation of the entire thick- ness of the parietes, resulting in the formation of a total fissure, the hippocampal (§ 259, C), and an ental eleva- tion, or colliculus, the hippocamp, along the medicornu; the hippocamp is thickened also, and in- timately associated with the fibres of the column already men- tioned. § 200. Fimbria.—In each hemicerebrum be- tween the hippocamp, with its corresponding cortex, and the rima, or line of intrusion of the paraplexus, there is a zone consisting of alba alone, and form- ing, as it were, a mar- gin for the hippocamp (Figs. 733, 735, and 759). This is the fim- bria (corpus fimbriatum, tenia hippocampt). § 201. The column and its caudal, curved extension, the hippo- camp and the fimbria, Fia. 736.—The Left Hippocamp and Ad- joining Parts. xX 5. (From Quain, altered from Hirschfeld and Leveillé.) 1, Apex of the temporal lobe; 1’, un- cus; 2, cut surface of the cerebral me- dulla surrounded by the cortex ; 3, at the apex of the postcornu ; 3’, collat- eral eminence; 4, part of the spleni- um, nearly medisected; 4’, points to the calcar; 5, cut end of the lateral portion of the fornix which is contin- ued at the hippocamp (5’) and the fimbria (6); 6, the fimbria; 6’, the terminal expansion of the hippocamp, ealled pes hippocampi; 7, dentate gyre (“fascia dentata”’). Preparation.— The left occipito- temporal region of the cerebrum was separated from the rest, together with a part of the splenium and fornix, and the dorsal and lateral parietes of. the postcornu and medicornu sliced away so as to expose nearly the entire ex- tent of the cavities. Defects.—The specimen had not been alinjected, and the figure looks somewhat diagrammatic, especially as to the dentate gyre (7) ; the actual ex- tremity of the medicornu does not ap- pear (see Fig. 728). There is no indi- cation, along the free margin of the fimbria, that one surface of this lamina was covered by pia and the other by en- dyma, and that they were continued in and upon the removed paraplexus. are simply portions of the prosocelian pari- etes, mainly of the par- acelian floor; they are continuous with the mesal wall, hemisep- tum (Fig. 782), and thus indirectly with the roof (callosum); excepting at the ven- tral end, in the tip of the temporal lobe, how- ever, their substantial continuity with the caudatum and _ tenia and other portions of the paracelian parietes is interrupted by the rima. It would be perfectly legitimate, therefore, to designate the irregular, elongat- ed portion of either paracelian floor, com- posed of hippocamp, fimbria, and fornicol- umn, by a special name, ¢@.g., hemiforniz. & 202. Commissure of the Forniz.—The parts compos- ing either hemifornix pertain each to its own hemicere- brum, and in brains in which the callosum is undeveloped, these have no connection across the meson dorsad of the aula and portas, representing the primitive mesal cavity of the prosencephal. So far as I know, the fornicommis- sure is thinner in man than in any other mammal; Fig. 731. § 203. The fornix is monographed by Honegger in the Recueil Suisse (zodlogie), 1890, v., 311-484. The hippo- camp has been treated by Alex. Hill, in a paper of which an abstract is published in the Royal Society Proceedings, vol. iii., p. 5. Variations in the form of the hippocamp and the collateral eminence are described by Howden in Journ. Anat. and Physiol., xxiii., p. 283, January, 1888. J. G. MacCarthy has described an interesting feature of the hippocampal structure in Journ. Anat. and Physiol., xxxili., p. 76, 1898. In the same journal are several re- cent papers by G. Elliott Smith discussing instructively the fornix and the commissures generally. § 204. Lyra.—When the fornix is transected through 180 the columns (Fig. 737) and turned caudad the exposed ventral surface, including the splenium, is seen to pre- sent lines which have been rather fancifully compared to the strings of a harp; the lyra is not a part, but merely a surface. § 205. Fig. 737 illustrates: A. The general form of the velum, a double fold of pia between the thalami and the superposed cerebrum, one of the layers belonging to each of the two segments (Fig. 710); the great veins are between the two, and others enter them from adjoining organs. The free lateral margins of the velum project into the paraceles as the paraplexuses (Fig. 720), and its rounded apex hangs in the aula and the two portas as the auliplexuses and portiplexuses (Figs. 721 and 724). B. The triangular form of the fornix; the cephalic, or “ascending ” part, consisting of the two parallel columns, constituting the so-called “anterior pillar”; it expands caudad, the sides being incurved instead of nearly straight, as with the cat, and at the splenium is quite wide. Each lateral half here is practically composed of | ii a ix ‘NR i i ili il Fig. 737.—The Velum and Lyra. X 1.5. (From Quain, after Sappey and Vicq d’Azyr.) 1, The narrower cephalic part of the velum; 2, left paraplexus, the margin of the velum which enters the paracele as the paraplexus ; 3, left velar vein, partly covered by the right; 4, columns, with small veins said to come from th2 callosum and se tum, the precornual veins; 5, tenial vein; 6, medicornual vein; 7, thalamic vein ; 8, vein from left medicornu ; 9, postcornual vein ; 11, body of fornix, transected and refiected ; 12, lyra; 18, on the lateral part of the fornix; 14, splenium. (The names here employed for the veins are those adopted in the article Brain, Circulation of, in this volume.) Preparation.—With a preparation such as is represented in Fig. 735, if the fornix were transected at its middle (f ), the caudal half turned caudad, and the cephalic half, with the attached hemisep- tums, removed down to the middle of the height of the portas, the appearances would be nearly as in the present figure. Defects.—The relation of the parts shown to the rest of the brain would be clearer if there were included at least an outline of one side or of the adjoining region. The tenias are omitted, between which and the fornical margins, fimbrias, the paraplexuses enter ; at the mesal side of each paraplexus should be a line, a ripa, indi- cating where the endyma covering the plexus was torn or cut in the separation of the fimbria. The whole, especially the lyra, is some- what idealized. * the corresponding hippocamp and fimbria, which, as they continue along the medicornu, are sometimes called the “posterior pillar.” REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, C. The nature of the lyra (§ 204). The line from 12 ends at the meson, the location of the fornicommissure or thin part connecting the thicker lateral portions. D. The double relation of the splenium to the callosum and the fornix. The larger part, body, of the callosum consists of fibres which pass laterad, dorsad of the para- celes, constituting their roof; at the splenium some fibres pass dorsad, some caudad, some ventrad, and others in intermediate directions; now all the constituents of the fornix form parts of the floors rather than the roofs of the paraceles, and at the splenium fornix and callosum become continuous. § 206. Modifications of the Prosocelian Parietes.—Pri- marily the cerebrum is a pair of lateral extensions of a small mesal rudiment, the first (cephalic or “anterior ”) encephalic vesicle; this forms their only bond of union with one another and with the other segments; their walls are thin and vary little in thickness or composition. Secondarily, the two hemicerebrums are closely conjoined by the callosum and other commissures; between the cerebrum and the crura (and thus the oblongata, the myel, and indirectly the entire body) are developed ex- tensive fibrous communications, the capsulas or “internal capsules”; the parietes are, for the most part, extraordi- narily thickened, the most notable, and physiologically the most important of these increments constituting what are commonly called the “corpora striata,” from the ap- pearance presented on sections of alternating strips of alba and cinerea. Each striatum, however, is now recog- nized as composed of an entocelian (“intraventricular ”) portion, the caudatum, and an ectocelian (“ extraventricu- lar”) portion, the lenticula (“lenticular” or “lentiform nucleus”), separated by the capsula already mentioned (Figs. 739 and 782). § 207. The Caudatum and Lenticula.—With all Rep- tiles, Birds, and Mammals, and at a very early period, the lateral wall and floor of the paracele present a more or less distinct elevation; in man, and some other mammals, the form is such as to suggest the application of caput to the cephalic (precornual) portion, and cauda to the taper- ing continuation along the medicornu, thus of caudatum to the entire mass (Fig. 735). Between the caudatum and the cortex the greatly thickened hemicerebral wall presents (a) the medullary lamina called capsula (§ 208); (0) next the cortex, a sub- circular disc of cinerea, the claustrum (Figs. 739 and 782); and (c) the lenticula, consisting of three zones, all more or less striated, the ental the smallest, and the ectal, also called putamen, the largest. The lenticula, like the claustrum, may be a dismemberment of the cortex. This entire region, from caudatum to operculums, is of great morphological as wellas physiological interest and should be studied in the other mammals. § 208. Capsula and Corona.—As already stated (§ 206) the capsula or “internal capsule” is the thick layer of fibres between the caudatum and thalamus mesad and the lenticula laterad; it is continuous with the crura caudad, and expands in the substance of the cerebral alba in such a way as to be called there corona (radiata). The histolog- ical and physiological aspects of the capsula and corona are considered in other articles; here an attempt will be made to indicate only their topographical relations by explanations of the accompanying figures (738 and 739). § 209. Mig. 738 illustrates: A. The general relations of the alba (medulla) to the ectocinerea (cortex). B. The locations of the two great masses of entocinerea (central tubular gray), the caudatum and the thalamus. C. The intermediate position of the lenticula, asa blunt wedge-shaped mass between the caudatum and thalamus. D. The position of the capsula (“internal capsule ”) as a stratum of alba between the lateral lenticula and the other two masses, and constituting a fibrous path for motor and sensory conduction between the cortex and the crura. E. The existence of two zones in the lenticula, the more lateral being distinguished as putamen ; a third would have appeared at a level farther ventrad (Fig. 739). F. The existence of a thin, cinereal lamina ectad of the lenticula, between it and the cortex; this is the claus- trum; it and the cortical corrugations of this region are shown upon a larger scale in Fig. 782. § 210. Fig. 739 illustrates: A. The existence and rela- tive positions of four important masses of connecting fibres, the callosum, columns of the fornix, precommissure, FRONTAL LOBE recornu P S caudatum fornicolumn ™ lenticula 2 thalamus OCCIPITAL LOBE Fic. 738.—Longisection of the Right Hemicerebrum at the Level of the Aula. Xx .05. (From nature [2,397] and from Gray.) Preparation.—The mesal outlines of the removed frontal and occipital regions were adapted from Gray. The plane of section corresponds nearly with the direction of the dotted line from aula on Fig. 739. The line A, B,C should have been dotted. This line and the one parallel with it mesad by the ‘‘internal capsule ’’ were introduced with reference to another figure which is not given here. and chiasma, differing from one another in either their direction or their appearance upon this section. The most ventral, the chiasma, is mainly a decussation, as. described in the article Cranial Nerves. The next, pre- commissure, isa true commissure, connecting correspond- ing regions of the temporal (and frontal?) lobes; at the: meson it is seen as a raised transverse band, but laterad, on account of its deflection caudad, it is divided ob- liquely, and appears as an eiliptical dottedarea. The two columns have at this level a nearly dorso-ventral direction, appearing as raised bands just dorsad of the precommissure (the line from the word aula ends upon the right), but they are curved in such a way as to be divided obliquely in two places—one at the level of the precommissure, and the other about 1 cm. (on this scale) dorsad. Finally the callosum, a true commissure, unit- ing corresponding regions of the cerebrum, is divided in the direction of its fibres. B. The general relation of parts and cavities at this important level. Two segments are represented—the diencephal (thalami, chiasma, and diaterma) and prosen- cephal (the remaining and much the larger part). Of the cavities, the mesal space between the chiasma and pre- commissure is the cephalic part of the diacele, the dark- est portion being the optic recess. The prosocele is rep- resented by the aula, the mesal space dorsad of and including the precommissure; by the considerable lateral cavities, paraceles ; and by the intervening portas. All these are true encephalic cavities, but the dark triangular area still farther dorsad is the pseudocele.. 181 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Three kinds of surfaces are included, viz.: entocelian, lined by endyma; ectocelian, covered by pia; and pseu- docelian, with no distinct membrane. There is ecto- cinerea (cortex), entocinerea (caudatum and thalami), and culums (see Fig. 782). pia intercerebral f, supercallosal f. 1 | Fa 2 fe "=~ callosal f. callosum roof of paracele H. The relations of the insula to the parts just named, and to the overlapping gyres which constitute the oper- I. The relation of the cinereal mass called amygdala to a fissure opposite the m of postoper- culum, which has thence been called the amygdaline fis- sure; Dwt, ates doubtless homolo- gous with the post- rhinal of quadru- peds. (§ 872, Fig. a3 chiasma \ claustrum N insula operculum postoperculum ¥ic. 739.—Transection at the Chiasma and Precommissure, Caudal Aspect. 1, Asubgyre (covered gyre) at the bottom of the su- percallosal fissure ; 2, margin of the cortex dorsad of the callosal fissure ; one-sixth and modified (compare Figs. 724, 738, and 782). the thalamus, faintly outlined on the other side; 5, capsula. Defects.—The dots representing cut fibrous areas are too heavy. The lines representing the callosal fibres are diagrammatic; one of them is interrupted. The pseudocele is not specified. The area cf the thalamus is too vaguely indicated. See § 210. what may, for the sake of a general term, be called medi- cinerea, the lenticula, and the claustrum, probably dis- memberments of the ectocinerea. C. The extension of the hemicerebrum nearly equally in three directions from the place of its morphological centre, the porta; were this brain not somewhat depressed by its own weight, the width and height would be nearly the same. D. The thickness of most of the parietes as compared with the earlier fetal conditions shown in Figs. 667 and 716; the hemiseptums and the terma, however, have re- tained their tenuity in great degree. E. The absence of the crista which was seen in a young brain (Fig. 793), and is constant in the cat (Fig. 686); whether it is absorbed or merely obscured in the human adult is not known (§ 366). F. The overlapping of the prosencephal at the sides of the diencephal, of the cerebrum upon the thalami. G. The relations of the several layers of alba and cinerea between the thalamus and the lateral surface of the cerebrum. The capsula (5) has an oblique direction, dorso-laterad, between the thalamus and caudatum and the lenticula (see Fig. 738). The lenticula itself com- prises three more or less distinct segments, each extend- ing farther dorsad than the one mesad of it; all present the alternating lines of white and gray which led to the application of stréatum to the united lenticula and cau- datum. The thin lamina of cinerea between the putamen, the most lateral division of the lenticula, and the insular cortex is the claustrum, and the alba between it and the lenticula is commonly, but inappropriately, called the “external capsule. ” 182 765.) § 211. Besides the precommissure, a medisection dis- plays two extensive lines of cut surface (Figs. 670, 682, 687, and 765), indicating that there was a continuity of the apposed, mesal sur- faces of the two hemicerebrums. Of these the dorsal, more extensive and more substantial, is the callosum (Figs. 724, 737, 739, and 740); the ven- tral is the commis- sure of the fornix (Figs. 782 and 748). § 212. Callosum. —When the fresh hemicerebrums are divaricated, as in Fig. 740, the bot- tom of the intercer- ebral fissure is seen to be formed by a white mass which unites them for more than the middle third of their length; upon hardened brains this, the callosum (corpus callosum, trabs cerebri, etc.), is easily determined to be fibrous, and somewhat firm in consistency, and to extend into the hemicerebral masses. At about the middle of its cephalo-caudal extent, the trend of the callosal fibres is almost directly laterad, but at the cephalic and caudal ends, especially the latter, the direction is oblique, giv- ing rise to the conditions known as preforceps and post- forceps (Figs. 785 and 740). The rounded cephalic region of the callosum is the genu, and the caudal, the splenium. As seen in medisections (Figs. 670, 687, and 743) the genu appears likea folding of the callosum upon itself, the ventral continuation being the rostrum, which, in man and other primates, is connected with the terma by the thin copula. The gentle curve of the.genu gives to the cephalic part of the pseudocele a rounded outline. § 2138. Mg. 742 illustrates: A. The primary continuity of the hippocampal and callosal fissures, and of the frontal extension marked 1. B. The existence of several early fissures, some of which are probably transitory. C. The continuity of the callosum, fornix, and terma. D. The degree of separation of the callosum and the fornix at this period, and the concomitant form and ex- tent of the pseudocele. § 214. Splenium.—This region of the callosum i is much less easy to understand than the genu from the study of normal adult brains, but most of the difficulties are re- moved or diminished by the study of fetal and hydro- cephalous specimens (Figs 742 and 743). From these it is clear that, like the genu, the splenium represents a paracele caudatum 3 precommissure (1) amygdala ‘~X fornicolumn (y) _ \ precommissure (m) ~~ diacele temporal lobe (From Dalton, by permission.) Reduced 3, tenial vein; 4, the cephalic part of REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain. Brain, flexion of the callosal sheet upon itself so that there is a dorsal lamina, a ventral lamina, and a caudal connecting portion ; commonly the dorsal and ventral portions are um are parts of the mesal wall of the precornu and postcornua respectively, while those which compose the (iP) ¢ ? A yy WY z H mn ‘\ 4 \ b : “ei : at We i's w) mi nN vil 1 a ul SA ¥ia. 740.—The Dorsal Aspect of the Callosum, Exposed by Divaricating the Hemicerebrums. (From Quain, after Sappey and Foville.) x 0.5. 1, Dorsal surface of the body of the callosum ; 2, mesal ridge or raphé ; 3, lateral ridges, bounding furrows in which, sometimes at least, are lodged the precerebral arteries; 4, lateral ridge, said to be formed by the arching of the callosum over the paracele; 5, cephalic curved margin, genu; 6, caudal curved margin, splenium ; ventral lamina and the splenium are parts of the para- splenium fornix me a callosum ‘ pseudocele genu F, bmp. /“* G. dnt. “fimbria Fic. 742.—Mesal Aspect of the Left Hemicerebrum of a Fetus, Measur- ing 16.8 em. from Heel to Bregma, and Estimated at}/Eighteen Weeks; 2,084. 1.5. 1, Cephalic extension of the primitive callosal fissure ; 2, 3, 4,5, short but distinct radial fissures, some of them probably transitory ; 6, point of refiection of the endyma from the fornix at the dorsal end of the porta; 7, point of reflection of the endyma at the tip of the rima upon its other margin, the tenia, which has been removed ; 8, region which would haye become the uncus; 9, tip of the temporal lobe; F'’. hmp., the hippocampal fissure; G. dnt., the dentate gyre (fasciola or fascia dentata) ; L. ol., olfactory bulb. Preparation.—The fetus was ill preserved and the head dis- torted; the entire head was medisected with a scalpel; the brain was so tender that the caudatum and plexus broke loose. Defects.—_The terma is shown too thick; the tenderness of the specimen did not permit determining the location and form of the chiasma and precommissure. 7, preforceps, callosal fibres passing cephalad into the frontal lobes; 8, post- forceps, fibres entering the occipital lobes; 10, cephalic portion of the cal- losal gyre, the line crossing the cepha- lic end of the supercallosal fissure ; 11, eallosal fissure; 12, caudal part of the callosal gyre, the line crossing the para- central gyre ; 13, cephalic surface of the cerebellum, the number being just cau- dad of the occipital fissure. Preparation.—While fresh the dor- ‘sal portions of the hemicerebrums were separated widely ; the curved margin of the callosal gyre (“gyrus fornica- tus’) has been detached and pushed lat- erad so as to expose more completely the extension of the callosal fibres into the hemicerebrum; caudad this gyre has been divided. See § 212. ‘in close contact, but in hydrence- phals (Fig. 743), as in the fetus at a certain stage, they are separated by a considerable interval; in these cases the pseudocele has a greater extent and a somewhat rounded caudal end. For the most part the callosum extends -dorsad of the paraceles, thus con- stituting their actual (though ndt primary) roof; but the fibres ex- tending obliquely cephalad and ccaudad from the genu and spleni- * This neuter noun is employed to des- ignate the primitive, undifferentiated mass or rudiment of a part, thus in the sense -of Anlage of the German embryologists (as adopted by Minot and others), and of fundament, as proposed by Mark (‘* Com- parative Embryology”). It avoids cer- ‘tain obvious objections to those terms as English words, is shorter than primordi- um (proposed. by Willey), and is in har- mony with the following phrases from Aristotle, kindly quoted by President B. As Wheeler : TO MpOTOV; TPWTH VAN; 7H TpaTn aitia, callosum genu splenium rostrum copula pseudocele prosoterma fornix precommissure diaterma chiasma haben Fig. 741.—Six Diagrams of the Devel- opment of the Human Callosum ; to be viewed from below upward. The chiasma and tuber are introduced merely to facilitate orientation by comparison with Figs. 670 and 687. In A the primitive end wall of the mesal series of cavities is undiffer- entiated but reinforced by the chi- asma which demarcates the tuber below and the terma above. In B the terma is reinforced by the pre- commissure, and its dorsal end (margin really, but seen as an end in medisection) is enlarged, consti- tuting the proton * or rudiment of the callosum and fornix. In C the elongation of the whole terma ren- ders more obvious its demarcation into the diencephalic portion (dia- terma) and the prosencephalic (pro- soterma) ; the calloso-fornical pro- ton presents a slight cavity or vacuole, the proton of the pseudo- cele. In D the callosum, fornix, and pseudocele are enlarged espe- cially caudad. In Eand F the proc- ess continues and all the adult structures are seen. The lateral septum, and it (the pseudocele) is never in communication with either the ental or the ectal surfaces. wall of the pseudocele is the hemi- celian floors, continuous with the fornix (Figs. 738 and 744). § 215. Mig. 743 illustrates: A. The complete separation of the fornix and callosum as far as the splenium, which is thus a com- mon bond between them, although usually, and perhaps properly, reckoned as a constituent of the callosum only. B. The concomitant extension of the pseudocele and of the hemi- septum. C. The large size of the porta. D. The wasted appearance of the visible gyres, in contrast with those of Chauncey Wright (Fig. 788). § 216. Mig. 744 tllustrates: A. The continuity of the splenium with both the floor, roof, and caudo-mesal wall of the paracele; some of the fibres pass dorsad, some ventrad into the hippocamp, while others, constituting the post- forceps, extend caudad into the calear, dorso-caudad into the occip- ital eminence, and ventro-caudad into the collateral eminence. B. The unusual distinctness of the occipital eminence, this being, in fact, the preparation in which it first attracted my attention (comp. Fig. 761). C. The prominence of the cal- car, here seen, of course, greatly foreshortened; of the left hippo- camp only a segment of the caudal convexity appears in this prepara- 183 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tion, with the collateral eminence just beyond (compare Fig. 735). § 217. Indusium.—This term (coupled with the adjec- tive grisewm) was given by Obersteiner (1892, p. 82) to supercallosal fissure callosum fornix porta pseudocele d Fic. 743.—Mesal Aspect of Part of the Right Hemicerebrum of an Adult Hydrocephalus; 747. % .7. The dorso-ventral line, d v, indicates the transection plane represented in Fig. 731. 1, Splenium ; 2, ven- tral surface of fornix ; 3, subsplenial gyres; 4, 5, ?; 6, collateral fis- sure; 7, uncus; 8, hippocampal fissure. The tip of the temporal lobe, included by the interrupted line just cephalad of v, indicates what was removed to expose the parts shown in Fig. 728. the thin layer of cinerea upon the dorsal surface of the callosum. It has been discussed by Giacomini, Blumenau, and more recently by Fish, 1893, a.* § 218. In several (perhaps half a dozen) brains in the Cornell museum the callosum presents a de- cided thinning at about the junction of the middle with the splenial third; most if not all of the individuals were mentally defect- ive in some degree. § 219. Incallosal Brains.—In addition to about fifteen cases of shortness or thinness of the callosum, there have now been reported at least a dozen instances of its complete ab- sence, together with the mesal part of the fornix. Commonly this deficiency was ac- companied with mental and physical weak- ness, amounting often to idiocy; but Malin- verni reported (Giornale del R. Acad. Torino, 1874; Gazette médicale de Paris, January 16th, 1875; Gazetta delle Cliniche, 1874, No. 15; London Medical Record, 1874, No. 73) the case of a soldier, forty years of age, who had been noted merely for melancholy, taciturnity, and lack of neatness. A case of total absence of the callosum and fornix is described and figured with unusual fulness by Alex. Bruce, in Brain, xiii., 171-190. There are included abstracts of previous cases and reduced copies of the illustrations of some. § 220. Fig. 745 tllustrates: A. The absence of the callosum and of the commissure (mesal part of fornix). B. The development of the columns as far dorsad as a point corresponding apparently to the dorsal limit of the aula and porta (which is not distinctly indicated). ©. The roofing in of the aula and diacele by a thin (membranous?) tela, the remnant of the primitive roof of the cavities. D. The absence of the medicommissure and small size of the precommissure, in contrast with the same parts in the incallosal cat (§ 221). E. The independence of the occipital fis- *T have to record with some chagrin that, upon a series of transections of an adult brain (1,824), sections of which are shown in Figs. 732 and 744, hardened in a mixture of ammonium dichromate and alcohol, the con- tinuity of the cinerea upon the callosum was recognized in October, 1880; notwithstanding its significance, fur- ther examination and publication were deferred. 184 sure, and the apparent junction of the calcarine with the hippocampal. F. The radial disposition of the mesal fissures; some of them probably represent the transitory fissures men- tioned in § 227. § 221. Among other mammals than man the total ab- sence of the callosum has been observed, so far as known to me, only in three cats examined in the anatomical laboratory of Cornell University; one of these (No. 381) has been described in my paper (1883, c), and was repre- sented in the first edition of the REFERENCE HANDBOOK, Fig. 4,835. At the Boston meeting of the Association of American Anatomists, December 29th, 1890, I showed the brain of a sheep (No. 2,844) in which the callosum is rep- resented, if at all, by a short thin lamina; but this speci- men, fortunately unmutilated and thoroughly hardened, has not yet been figured or described. § 222. Pseudocele (“fifth ventricle,” “ventriculus septi pellucidi”).—This compressed, subtriangular mesal cav- ity has no connection with the true encephalic cavities. either in the adult or at any stage of development. Its anatomical relations are shown in Figs. 687, 782, 785, and others; but they are more clearly understood from the series of diagrams in Fig. 741 based upon my own speci- mens and the account of Marchand (“Ueber die Ent- wickelung des Balkens im menschlichen Gehirn,” Archiv Siir mikr. Anat., Xxxvii., pp. 298-334). § 223. In the-cat (Fig. 682) and mammals generally, both the anatomical and developmental conditions are different. The fornix commissure and the callosum con- stitute portions of two lines of secondary junction of the two hemicerebrums and are continuous at the splenium supercallo~ “~ ) sal fissure =....callosal f. 4-...-..callosum sen sense ; occipital eminence BL. ip oieie,« era COLCRES 2 § collateral eminence .- hippocainp» Fig. 744.—Transection of an Adult Brain through the Splenium; 1,824. x1. 1, Postcornu ; 2, section of a subsplenial gyre. Preparation.—The brain was that of a Pole, male, and was received in the head through the kindness of Dr. F. Cary, a former student. object of furnishing reliable preparations for the elucidation of the celian pari- etes (see Fig. 732), the sides of the head were sawn off so as to expose the medi- cornu, and into this was injected a mixture of alcohol (95°) and water, each 2 litres, ammonium dichromate, 10 gm.; the same was injected into the arteries. When the brain was completely hardened it was removed and transected at in- tervals of about 1 cm. pe Cate ee lines representing the callosal fibres should be continued across e meson. With the special REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. wld Brain, as in man; but cephalad the callosum ends as a point so that the triangular area is not completely circumscribed ; ’ commonly, also, the interval corresponding to the pseu- gations of the wall (Fig. 747). They do not branch. Their general direction is radial. By the end of the fourth month they disappear from the lateral surface docele is narrower than in man. (Fig. 748) and partly at least from the mesal, although § 224. In three apes (orang, gorilla, and chimpanzee*) | there is reason to believe that two of them may be prac- lam. term. r “Sule. call. marg. } ! Any sule. centr. T R. gyn. fornic \ preecun, sulec. occ. trans. f/ _fiss. cle. mm / Ne ; sule. occ. temp. inf. i : ¢ Xe g. hipp. col. ant.forn. sp.lue. / 4 \ x puly. thal, * com. ant. i } schn 1. perf. ant. tr. opt. \ gyr. une. Fic. 745.—Mesal Aspect of the Right Hemicerebrum of an Incallosal, Microcephalic, Adult Brain. X .93. (From Onufrowicz.) -Abn., abnor- mal radiating fissures; Col. ant. forn., fornicolumn; Com. ant., precommissure; Cun., cuneus; Fiss. cle., calearine fissure; Fiss. par. occ., occipital fissure; G. hipp., hippocampal gyre; G. unc., uncus; L. perf. ant., precribrum; Lam. term., terma [aulatela and dia- tela]; ling., subcollateral gyre; precun., precuneus; Pulv. Thal., pulvinar (of the thalamus); R. gyr. fornic., margin of the callosal gyre (gyrus fornicatus) ; Schn., cut surface between the diencephal (thalami, etc.) and mesencephal (gemina) ; Sp. luc., hemiseptum [?] ; Sule. call. marg., supercallosal fissure [7]; Sule. centr., central fissure; Sulc. occ. temp. inf., collateral fissure; Sule. oce. tr., “* trans- verse occipital fissure’ [?]; Tr. op., optic tract. Preparation.—This was the brain of a male idiot, thirty-seven years of age, who had never learned even to feed himself; it seems to have been obtained fresh early and well preserved; the paper (‘‘ Das balkenlose Mikrocephalengehirn Hofman,” Archiv fiir Psychiatrie, 1887, xviii., pp. 1-24) from which the figure is taken is by Onufrowicz, but this and most of the other figures are by Forel. There are sey- eral transections, but the laek of distinct indication of endymal continuity renders them less instructive than they might haye been. The weight of the entire brain is not stated. See § 220. and in all the monkeys examined by me the conditions are aS in man; the mode of development is not known to me. § 225. To English-speaking anatomists interested in Om4 8 2 1 ee Fia. 746.—Right Side of the Brain of a Fetus Measuring 49 mm. from Nates to Bregma, and Esti- mated at Twelve Weeks; 1,828. * 1.4. (The left side of the same is shown in Fig. 673, where the mode of preparation is described.) the morphology of the cerebral fissures and com- missures are particularly commended the _ recent writings of TD. J. Cun- ningham, and G. Elliot Smith in the Journal of Anatomy and Physiology. § 226. Mig. 746 tllus- trates: A. The condition and relative size of the encephalic segments at this period. Bo The presence of transitory fissures which are absent from the other hemicerebrum (Fig. 673). C. The indication, so far as these transitory fis- sures are concerned, that in this individual the right hemicerebrum was more advanced than the left. § 227. Transitory Fis- sures.—During the third and fourth months both the lateral and mesal sur- faces of the cerebrum present linear depressions corre- sponding with ental ridges and thus representing corru- * A gibbon brain has not yet been available. ~ tically perpetuated by the formation of the permanent calcarine and occipital fissures along the same lines (Fig. 730). § 228. Mig. 747 illustrates: A. The great size of the paraceles and paraplexuses at tlris stage; compare Fig. 667. a lateral fissure paraplexus a mesal colliculus a lateral colliculus a lateral gyrus a mesal fissure 1 part of falx Fic. 747.—Transitory Fissures of a Fetus Measuring 5-6 cm. from Ver- tex to Nates, and Estimated at Fourteen Weeks; 2,770. X 2.2. Preparation.—After the exposure of the brain the frontal end of the cerebrum was sliced off so as just to clear the large paraplexuses. Of the falx all was removed excepting the fragment shown. The head was tilted so that the face is much foreshortened. 185 Brain. Brain, B. The slight and nearly uniform thickness of the parietcs. C. Suggestion of a wrinkling or corrugation of the parietes as if from growth within a confined space. transitory fissure ® quadrigeminum cerebellum oblongata myel i Sylvian fossa Fia. 748.—Fetus Measuring 7 cm. from Nates to Vertex, and Estimated at Fourteen Weeks; 2,761. X .9. Neg. 1,090. Received in weak alcohol and injected through the umbilical vein with alcohol and zine chlonide. D. The approximately symmetrical distribution of these corrugations. E. The length of the fissure on either side, reaching from the Sylvian fossa nearly to the meson. F. The absence of any indication of branching. § 229. Fig. 748 tllustrates: A. The large number of - transitory fissures at this stage. B. Their general arrangement as radiating from the Sylvian fossa; compare, however, Fig. TAT. C. The considerable difference in their length; one of the longest is indicated by the line from “transitory fissure”; one of the shortest is just below it. postoperculum § 230. Transitory Fisswres Prob- falx ably Mechanical in their Origin.— The simplest explanation seems to be that their formation is due to the growth of the cerebral walls at a rate more rapid than that of the cranium; and that their dis- appearance results from the yield- ing or more rapid growth of the cranium. § 231. Fig. 749 illustrates: A. The disappearance of the trans- itory fissures, at least upon the lateral aspect. B. The concomitant increase in the length of the cerebrum, apparent- ly from the development of the occipital region; compare Figs. 667 and 673. C. The non - appear- ance of the lambdoidal fissure (Fig. 750). D. The commence- Sylvian fossa Fic. 749.—Fetus Measuring 8.8 cm. from Vertex to Nates, and Esti- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. culum as a fold of the temporal lobe projecting over the Sylvian fossa. E. The non-appearance at this stage of the other oper- culums or of any elevation indicating the future insula. § 232. Abnormal Persistence of Transitory Fissures.— In several brains lacking the callosum (e.g., the one shown in Fig. 745), the mesal permanent fissures present the radial arrangement characterizing the transitory fissures. This condition likewise exists upon the lateral aspect in the case described by Hans Virchow and shown by Cunningham (1892, Fig. 7). § 288. Are Transitory lissures Peculiar to the Human Brain ?—Hitherto, as remarked by Cunningham, they Fig. 750.—Dorso-Caudal Region of the Cerebrum of a Fetus Measuring about 30 cm. from Heel to Bregma, and Estimated at Six Months; 1,817. x 1. 1, Sagittal suture; 2, lambdoidal suture; 3, right lambdoidal fissure ; 4, left lambdoidal fissure. 5 Preparation.—The entire fetus had been preserved in: alcohol. From the left side the calva and dura were removed, excepting a narrow strip along the meson ; on the right there was left a trape- zoidal area, 12 to 25 mm. wide, including most of the sagittal and lambdoidal sutures. have been observed only in man. Before, however, con- cluding that they constitute a real human peculiarity they should be looked for in the other primates, where I believe they will be found at corresponding periods of development; the examination of the fetal gorilla de- scribed by Duckworth will be interesting in this respect. Cunningham has considered the transitory fissures quite fully, but the subject re- quires further investiga- tion. § 234. Lambdoidal Fis- sure.—In several fetuses estimated at from three to seven months I have observed a fissure direct- ly underlying the lamb- doidal suture (see Figs. 750 and 761, and my pa- per 1886, a). It is ap- parently identical with what are called by Cun- ningham “external cal- carine” and “external perpendicular ” (1892, a, Plates I. and II.); but I am unable to concur in his disposition of the matter or to decide whether the fissure dis- appears or persists (see Fig. 777). § 285. Fig. 750 tllus- trates: A. The distinct collocation of a fissure and suture at this period. B. The early appear- ance (or late disappear- ance?) of this, the lambdoidal fissure; ex- cepting, perhaps, the dorsal end of the occipi- ment of the postoper- 186 mated at Four Months; 2,644. .9. It is not very well preserved and the cerebrum is evidently shrunken. tal, the rest of this re- gion is smooth. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, C. The peculiar sharpness of outline, reminding one of the transitory fissures (Figs. 746 and 747; § 227). § 236. Intercerebral Fissure.—The interval between the apposed, mesal surfaces of the two hemicerebrums is the intercerebral fissure (“interhemispheral,” “sagittal,” presylvian f. operculum. Sylvian f. | insula | ' i central f. | ; iy = Oh a ee olfactory bulb 2 3 4 Fic. 751.—Left Fetal Hemicerebrum ; 1,820. x1. 1, Orbital region, unfissured ; 2, temporal lobe, unfissured ; 3, slight furrow, the pre- occipital fovea; 4, circular depression, unidentified (see § 241). Preparation.—The fresh hemicerebrum was placed in a mixture of alcohol and glycerin, equal parts; after two days half the mix- ture was replaced by alcohol; after two days more alcohol alone was used, and renewed on the following day. The original mix- ture seemed to prevent the usual distortion of fetal brains, and to facilitate the removal of the pia. Unfortunately the age and size of the fetus were not recorded. or “great longitudinal”) (Figs. 682, 707, and 739). It differs from ordinary fissures in the following respects: 1, It is mesal or azygous, while all others are lateral or in pairs; 2, although its sides are formed by cinerea, its bottom, the callosum, is apparently alba, with a com- paratively thin layer of cinerea, the indusium, § 217; 3, although the pia has the usual relation, the arachnoid, instead of passing directly across, dips into it to a greater or less depth on account of the falx (Figs. 687 and 732); 4, it is, in one sense, a Superfissure (§ 328) since in its depths are concealed the callosal fissures. § 237. Poles and Lobes of the Cerebrum.—The two ends of either hemicerebrum are distinguished as the frontal and occipital poles respectively, and the tip of the temporal lobe as the temporal pole. For topographical convenience, and not be- cause they represent perfectly natural di- visions, either anatomical, histological, or physiological, each hemicerebrum may be regarded as forming five lobes, the insula and the frontal, parietal, occipital and tem- poral lobes (Figs. 757 and 758). In a gen- eral way, but by no means accurately, the last four lobes coincide with the cranial bones for which they are named. § 238. The insula (lobus opertus, “cen- tral lobe ”) is nearly or quite covered in the adult brain by folds (operculums) from the adjoining lobes (Figs. 762 and 767); except- ing at part of the ventral side the insula is surrounded by an irregular furrow, the circuminsular fissure (Figs. 781 and 782). § 239. The other four lobes have more or less complete natural boundaries on either gupercentral f= superfrontal f.__ _ — subfrontal f...- presylvian f..._ ' subsylvian f.. .- olfactory bulb..-~~ and an occipito-temporal portion, and the latter again into a temporal and an occipital lobe by artificial lines drawn from the preoccipital fovea, the indentation of the ventral margin corresponding with the petrous portion of the temporal bone (represented by the emargination opposite the word collateral in Fig. 757) to the splenium on the mesal aspect and on the lateral to the extremity of the Sylvian fissure. § 241. Hig. 751 illustrates: A. The early appearance of the Sylvian, presylvian, and central fisures, and of a depression which perhaps represents the beginning of the paroccipital. See the ventral surface of this specimen (Fig. 789). B. The nearly uncovered and slightly fissured condi- tion of the insula at this period; the faint dorso-ventral line just caudad of the end of the line from insula rep- resents the just commencing transinsular fissure. § 242. Permanent Fissures.—The surface of the adult cerebrum presents alternating depressions, fissures, and elevations, gyres (or “convolutions”). The fissures vary in depth from 1 mm. to 30, and in length from 1 cm. to 10. The intervals between the fissures (and thus the width of the gyres) vary greatly, but an adult brain seldom presents an unfissured surface more than 20 mm. in width. Notwithstanding considerable variations in different brains, and in different parts of the same brain, one can hardly fail to be impressed with the approximate uniformity of the interfissural spaces (when viewed squarely, as suggested under Fig. 763), as if the fissures were produced mechanically by the extension of the sur- face within a confined space. § 248. Hig. 752 illustrates; A. The condition of the insula and operculums at this stage. The former is dis- tinctly elevated, but as yet perfectly smooth, while in the otherwise less advanced brain shown in Fig. 751 it has a slight transinsular furrow. The subsylvian fissure is just forming as the ventral boundary of the preoper- culum. B. The demarcation of the subfrontal gyre by the sub- frontal fissure. C. The non-continuity of the parietal and paroccipital fissures. D. The non-appearance of the precentral and post- central fissures. E. The peculiar triangular depression which seems .-..central f, av WA Awa ee yy, nw om swee ove eee.. Parietal f. Postwncse wees OV 1 VIAL te pee) ...paroccipital f. -Supertemporal f, insula flocculus - ~ oliva_ __ ¥ GP _..- postoblongata the lateral or mesal surface, but not on both. The primary division is by the line of the central fissure (Fig. 751) into a frontal region and an occipito-temporo-parietal re- gion. The former, although commonly ac- FG. 752.—Lateral Aspect of the Left Half of the Brain of a Fetus, Size and Age Un- known; 2,278.. < 1.. 1-8, Fissures not identified with certainty. On the temporal lobe, just dorsad of the pons, the apparent fissure is an artificial crack. ; Preparation.—The brain was medisected while fresh and this half placed in al- cohol upon its mesal aspect ; it has become thinner and wider than natural, but ex- hibits the fissures more perfectly on this account. cepted as a single lobe, is so extensive as to be conveniently subdivided by a line continued dorso- cephalad from the presylvian fissure into a postfrontal and prefrontal lobe, the latter including the orbital sur- faces. § 240. The region caudo-ventrad of the central fissure line is divided first by the occipital fissure into a parietal to represent the commencement of the supertemporal fissure. F. The presence of three fissures or series of fissures caudad of the supertemporal, the middle of which may represent the exoccipital (§ 344). G. The interruption of the central fissure near its dorsal 187 Brain. Brain. end; so much as appears in the figure is continuous, but near the mesal margin of the hemicerebrum is a slight depression separated from the longer lateral portion by an isthmus (comp. Fig. 772). H. The small size of the cerebellum, the distinctness of the flocculus, and the prominence of the oliva. callosum fornix ie pseudocele ..... 4 3 h ia Ye gees supercallosal f. { \ olfactory bulb...._._.- ,. occipital f. _.calearine f. .collateral f. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tinuous with the fissure only superficially; the cephalic branch isapparently my adoccipital; the caudal, although doubtless the dorsal part of the occipital, presents an unusual curve and is invisible from the lateral aspect. F. The extent of the precuneal fissure. G. The considerable extension of the central upon the mesal aspect. H. The presence of a subcalcarine fissure. § 247. Each of the forty or more fissures demands monographic treatment; but the limits of this article will permit the detailed consideration of only two, the central (§§ 269-308) and the paroccipital (§§ 309-825), as exemplifying different phases of fissural study. § 248. Mig. 755 illustrates: A. An early stage in the formation of the Sylvian fissure, the presylvian fissure being represented by a mere notch. B. The incomplete separation of the calcar and the occipital eminence. C. The size of the postcornu relatively to that of the entire hemicerebrum. callosal f. Fic. 753.—Mesal Aspect of the Left (Reversed) Hemicerebrum of a Fetus, Size and Age Unknown; 2,278. 1. The lateral aspect of the left half of the same brain is shown in Fig. 752. 1, 2, Rostral fissures ; 3, tip of temporal lobe; 4, ventral end of hippocampal fissure; 5, uncus; 6 (should have been extended a little farther so as to reach the light band), fimbria; 7, dentate gyre (fascia dentata) ; 8, un- D. The corrugation constituting the collo- cated calcar and calcarine fissure. E. The equally distinct collocation of the occipital fissure at this period with the ad- determined fissure. § 244. A cerebral fissure is a narrow space vacant of brain tissue and containing only a fold of pia with blood- vessels; yet it has many and sometimes important reia- tions, a complete account of which would embrace about fifty distinct topics. There are also about one hundred problems of a more or less general nature applying to several or all of the fissures. § 245. Mig. 753 illustrates : A. The existence of three in- dependent furrows between the callosum and the margin of the hemicerebrum along the line of what is common- ly called the calloso-marginal fissure. B. The distinctness at this period of the four total or collicular fissures, occipital, calcarine, collateral, and hip- pocampal. C. The independence of the central f. paracentral g. paracentral f. callosal g. __ callosal f anne ‘ callosum — occipital and calcarine. D. The extension of the calcarine alone nearly or quite ; splenium - as far as the point reached in some other brains by the 6 occipital alone or by the stem fasciola of the two. Sometimes the occipital is the longer in the fetus and occasionally, as in Fig. 754, union fails to occur. § 246. Mig. 754 illustrates : A. The complete separation of the calcarine fissure from the occipital by a calcarine isthmus. On the other side the two are connected as usual. B. The bifurcation of the calearine at each end, consti- tuting a long zygal fissure (§ 307). C. The extension of the occipital fissure so as to fepresent what is usually the common stem of it and the calcarine. D. The presence of a “spur” extending caudad from the occipital toward the calcarine upon the isthmus. E. The appearance of trifurcation of the dorsal end of the occipital. The middle extension, however, is con- occipital f. - hippocampal g. __ collateral f. -- subcollateral g. {fareee 188 joining colliculus, occipital eminence, some- times called “bulb of the posterior cornu.” § 249. Collocation of Permanent Fissures with Cranial Sutures.—In the adult the dorsal end of the occipital fissure has a notably constant position at the mesal angle of the lambdoidal suture, as seen in Fig. 670. With fetuses of between three and seven months this suture is decidedly caudad of the occipital fissure, but is distinctly paneer antes =--~—-—---—~--precuneal f. ed as oa aa =e PreCuneus ee t occipital f. _—-— cuneus. ___ calearine isthmus 2 - calearine f. subcalearine g. - Subcalcarine f. - postealcarine f. . collateral f. Fig. 754.—Caudal Half of the Mesal Surface of the Right Hemicerebrum of an Adult Female Paretic. No. 2,358 in the Museum of Cornell University. 1. collocated with the lambdoidal fissure (Fig. 750); this collocation does not persist after the seventh month, and it is not yet known whether the fissure disappears or changes its position. The approximate collocations of the central and other fissures with sutures are considered in the article Brain, Surgery of the. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. —_— Brain, Brain, § 250. Fissures should be studied before gyres, because: 1, They are simpler, being represented by lines instead of planes; 2, they are more commonly entirely independ- ent of other fissures; 3, they are comparable with the rivers of a region which are employed as boundaries of operculum - presylvian f. . Fic. 755.—Left Hemicerebrum of a Fetus, Size and Age Unknown. Opened from the lateral aspect; 1,819. x 1. 1, Obliquely cut surface; the unshaded area repre- sents a surface cut parallel with the meson. The line from paraplexus ends somewhat vaguely; it should reach the narrow zone between the hlppocamp and the cut surface marked 1. See § 248. the subdivisions; 4, themselves structureless, they really represent the locations of a greater amount of cinerea than lines of equal width and extent on the gyres, and have thus a greater, presumptive, physiological sig- nificance, although there seems to be a difference of opin- ion as to the functions of the intrafissural cinerea, § 251. With children born at term the main fissures are always well defined, and in some cases there seems to be lit- tle difference between infant and adult cerebrums in respect to fissural complexity, although the insula is always less devel- oped and less completely cov- ered by the operculums (see Fig. 663). Such brains are often more readily obtained and removed than those of adults, and if well preserved and carefully handled may materially aid both teach- ing and research. § 252. For the elucidation of the intricacies of adult fissures, fetal brains are much more ser- viceable than those of monkeys. This, in contravention of the view and practice of Meynert, has been insisted upon by me (1886, g). Some of the pecu- liarities and complexities of the monkey brain are represented in Fig. 787. § 258. Adult cerebrums com- monly present individual pecu- liarities which prevent their serv- ing as types or standards. I have found such in every brain examined; not merely, for ex- ample, in that of the philoso- pher, Chauncey Wright (Figs. 768, 770, 788) but also in that of a mulatto; simple in several re- spects, it has peculiarities and complexities not as yet fully understood (see Figs. 762-766). § 254. Fig. 756 illustrates: A. In connection with Figs. 663 and 702, the perfection and beauty of form of the human brain at birth. B. The relatively small size of the cerebellum at birth. C. The distinctness and prom- inence of the pons. a olfactory bulb 31” — D. The lateral extent of the pseudocele; at the genu (cephalic curvature) of the callosum it is 1 mm. deep, representing about one-half of its entire lateral extent. E. The distinctness and depth of the principal fissures and the large number of minor ones. F. The peculiar ventral curve of the cau- dal half of the calcarine fissure, and the con- comitant expansion of the cuneus. ol G. The length of the fissure in the sub- calcarine gyre. H. The appearance of the cephalic stipe of the paroccipital fissure (18) upon the meson (see Figs. 774 and 775). § 255. The study of fissures upon actual brains is facilitated by reference to diagrams such as have been published by C. L. Dana, Eberstaller, Ecker, Jensen, Pansch, ‘Schiifer (in “Quain”), and others. My present views are embodied in Figs. 757 and 758. § 256. Comments upon the Fissural Dia- grams (Figs. 757 and 758).—A. They repre- sent my views at this time, but are not identical with those previously published (1886, g, and first edition of the REFERENCE HANDBOOK), and are subject to further modi- fications with increasing knowledge of the facts. For example, the small fissures caudad of the occipital are but little understood, and the orbito-frontal of Giacomini may prove to be more nearly constant than now supposed. B. An attempt has been made to indicate the relative depth and constancy of the fissures by lines of three de- grees of width; this grouping, however, is provisional. _- Sylvian f. -occipital f. posteornu . calcar ~~ collateral em, ___>>+hippocamp ~~=. paraplexus ~7—=—~=<- collateral f. callosum fornix _paracentral g. \ peeuttoeclo } diatela ‘central f. ’ 7 ,paracentral f. callosal f. x 16 19 20 calearine f. 7 o - optic n. q medicommissure 6 / albicans pons f SY 231 25 \ thalamus Fig. 756.—Mesal Aspect of the Right Hemicerebrum of a Male Child, at Term; 478. X .84. Other aspects of the same specimen are shown in Figs. 663, 774, and 775. 1, Postoblongata ; 2, preob- longata ; 3, postgeminum ; 4, pregeminum:; 5, thalamus, its mesal surface, forming the lateral wall of the diacele ; the dorsal, pial surface is designated by the line from the word thalamus ; these are parts of one and the same organ, separated by the membranous diatela ; but the trian- gular area dorso-cephalad of them marked pseudocele and apparently separated only by the nar- row white area marked fornix, is the hemiseptum, part of the mesal surface of the cerebrum ; 6, 9, 16, 17, 21, 23, 24, 25, 26, 31, unidentified fissures; 7, postrhinal; 8, olfactory; 10, 11, rostral fissures; 12, supercallosal fissure, continuous with the paracentral; 15, intraparacentral fis- sure; 14, inflected fissure ; 18, cephalic stipe of paroccipital fissure ; 19, a ventral branch of the occipital fissure ; 20, 21, intracuneal fissures; 22, dorsal branch of the calcarine fissure; with the more caudal of the two ventral branches perhaps it represents the forked fissure sometimes called postcalearine ; 27, precuneus; 28, precuneal fissure; 29, dorsal end of the occipital fissure ; 30, the common stem of the diverging occipital and calcarine. Defects.—The specimen spread while hardening under its own weight, and is therefore wider and thinner than natural; this is, however, an advantage for the study of the fissures. The naturally considerable cranial flexure became still more marked as the brain rested upon the lateral aspect while photographing, and this, for convenience, is preserved in the draw- ing. The thalamus is unnaturally, though very instructively, uncovered by the callosum so that its caudal prominence, the pulvinar, is visible. The habena is not distinctly seen. The cerebellum is not represented accurately as to details, but is enlarged in Fig. 702. The hypophy- sis is lacking, and the aulic region is not shown in detail. 189 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ©. Each separate line represents what I now regard as a fissural integer so far as the human brain is concerned. The following are also regarded as integers, although continuous with others: occipital, calcarine, postcalca- tnflected J. entral f, nections are (1) of / PARACENTRAL G. ‘calcarine f. SUBCALCARINE G. BAO TIVLIdIO00- Fic. 757.—Diagram of the Fissures upon the Mesal Aspect. The outline and certain fissures are from the mulatto brain (322), which was hardened within the cranium. 1, Postrhinal (amygdaline) fissure ; 2 and 3, rostral fissures. rine, postrhinal. The presylvian, subsylvian, and basi- sylvian are really branches or continuations of the Syl- vian, but are separately named for convenience. D. The fissure lines are nearly straight and simple, SUBPARIETAL G. me HO. "TwLIdIN00 olfactory f. basisyluian f. Fig. 758.—Diagram of the Fissures upon the Lateral Aspect. The outline and certain fissures are from the mulatto brain (322), which was hardened within the cranium. M, the **mar- ginal’ gyre; A, the “angular” gyre; Preop., the preoperculum; Subop., the subopercu- lum ; Subsy. f., the subsylvian fissure. The interrogation points on the lateral aspect of the occipital lobe indicate my doubts as to the existence of certain fissures, or as to the names that a ee be applied to them if they do exist. The subtemporal fissure is not shown (see Fig. 765). writers of what seem to be the best fissural names of a single word each—eg., from Huxley, collat- eral; from Owen, callosal, hippocampal, medifrontal, subfron- excepting where branching is a practically constant feature, as, ¢.g., with the paroccipital, paracentral, pre- cuneal, and postcalcarine. E. The connections are of two distinct kinds: primary, invariable, and inevitable from the mode of formation of the parts; secondary, and more or less common, but not necessary. F. Jnvariable and apparently inevitable fissural con- 190 the Sylvian with the basisylvian, presylvian, and subsylvian, all which might be re- garded as its continuations or branches; (2) of the cal- losal with the hippocampal. G. Usual connections are of the occipital with the calcarine, and of the supercallosal with the paracen- tral, but there are occasional excep- tions. H. Common connections are of the superfrontal and supercentral; the precentral and subfrontal; the pre- central and supercentral; the post- central and subcentral and parietal; the parietal and paroccipital. I. Occasional connections are of the precentral with the Sylvian, and of the central with the Sylvian over the margin of the operculum; in these cases, so far as known to me, the junction is seldom very deep. § 257. From the deservedly pop- ular fissural diagrams of Ecker, the publication of which has so materi- ally advanced the general knowl- edge of the subject, these differ» mainly in the following respects: A. The omission of branches and contortions. B. The inclusion of the callosal, inflected, adoccipital, postrhinal, postcalcarine, medifrontal, precu- neal, and postcentral fissures. C. The disjunction of the supercallosal from the para- central; of the precentral from the subfrontal and super- central; of the postcentral from the subcentral; and of the subcentral from the parietal. D. The recognition of the adoc- cipital fissure and the cuneolus, E. The introduction of the ex- occipital as probably representing the true “ape-fissure ” of Wernicke. F. The combination of the “ trans- verse occipital” of Ecker with the caudal portion of his “interparietal” as a distinct fissural integer, the paroccipital. G. The adoption from various. _ postcornu - Calear A : _calcarine f. pia ’ endyma operculum hippocampal f. Fig. 759.—Schematic Transections of the Three Paracelian Cornua in the Order of their Complexity. See § 259. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, tal, supercallosal ; from Wernicke, fronto-marginal ; from Jensen, tntermedial ; from Pansch, oce7pital and parietal ; from Schwalbe, precentral and postcentral ; from Mey- nert, preoccipital ; from Lussana and Lemoigne, inflected (Ital., ¢nflesso). H. The substitution of several mononyms for polyo- nyms, viz.: of presylvian for ascending branch of the Sylvian ; subsylvian tor anterior branch ; basisylvian for the part ventrad of the presylvian; and the restriction of Sylvian to the “ posterior branch.” I. The replacement of lingual lobule and fusiform lobule Fig. 760.—Transection of the Left Occipital Lobe of a Fetus, Size and Age Unknown; 2,278. 1.5. This figure is almost diagrammatic in its simplicity ; it shows very clearly the relation of the calearine fissure to the calcar as represented in Fig. 759, A. (not at all easy to apply correctly), by subcalearine gyre and subcollateral gyre, names at once associated with the fis- sures which respectively constitute the dorsal boundaries. J. The use of one and the same word, fissure, for all the cerebral depressions excepting the two foveas. inflected f. superfrontal f. orbital f. presylvian f. basisylvian f. INSULA Fig. 762.—Lateral Aspect of the Left Hemicerebrum of a Mulatto ; 322. K. The use of one and the same word, gyre, for all subdivisions of the lobes, excepting the cuneus and pre- a ae - caudatum hippocamp oceipital eminence __ 3 occipital fissure ___ y ~~~ ~--7- Paraplexus calear, .—- cane ae fe postcornt: calcarine fissure __ lambdoidal f. FiG. 761.—The Caudal Part of the Right Hemicerebrum of a Fetus, Measuring 14 cm. from Nates to Bregma, and Estimated at Four Months; 1,816. 1.5. (See § 261.) Preparation.—This is part of the specimen shown in Fig. 727, where the mode of preparation is described ; the postcornu was ex- posed by removing the paracelian roof along the lines in that figure. aoe plexus was partly cut away, although not so represented in this gure. cuneus, already well distinguished by mononyms, and the cuneolus. § 258. Total and Partial Fissures.—Of the permanent fissures most affect merely the cortex and the adjacent alba and are therefore sometimes called partial fissures ; the central, for example, though constant and deep, is only a partial fissure. But others represent corrugations of the entire parietes, so that the ectal depression, fis- sure, is opposite and obviously correlated with, an ental precentral f. supercentral f. subfrontal f. | supertemporal f. elevation or colliculus; the fissures commonly enumer- central f. postcentral f. subtemporal f. meditemporal f. x .8. 1, Cephalic part of the operculum demarcated from the rest by a fissure that does not extend through its entire thickness; 2, preoperculum ; 3, postoperculum ; the subsylvian fissure is probably repre- sented by a short indentation, visible only when the postoperculum (8) is removed; 4, what is commonly called the “ supramarginal gyre”; 5, may represent part of what is called the “angular gyre’’; 6, a supergyre overlapping the concealed, caudal part of the angu- lar ; 7, unidentified occipital gyre ; 8, 9, portions of the unidentified supergyre that overlaps the lateral part of the paroccipital gyre ; 10, gyre at the caudal (apparently dorsal) side of the dorsal, deflected end of the supertemporal fissure ; 11, opposite the dorsal end of the oceip- ital fissure (this is, however, invisible, and the straight fissure that extends laterad from 11 between 8 and 9, and curves ventrad at 6, may possibly be the exoccipital or Wernicke’s fissure, one of the so-called ** ape-fissures”’; it has apparent, though not real, connections with the occipital and supertemporal fissures) ; 12, curved fissure in the same supergyre, superficially connected with the supertemporal ; 18, cephalic stipe of the paroccipital fissure ; 14, dorsal fork of the postcentral fissure ; the subcentral is not indicated by a separate num- ber and is continuous with the postcentral; 15, caudal extremity of the calcarine fissure, really simple and independent ; 16, cephalic radius of the triradiate supercentral fissure (see Fig. 765) ; 18, 19, 20, unidentified occipito-temporal fissures ; 21, just ventrad of the strait between the central and supercentral fissures (see Fig. 764) ; 22, the most cephalic of three distinct fissures crossing the medifrontal gyre. 191 Brain. Brain. ated as total are the hippocampal (Fig. 755), calcarine (Fig. 760), and collateral (Fig. 755); the Sylvian may Fic. 763.—Diagram Illustrating the Effect of the Convexity of the Cerebral Surfaces upon the Apparent Width of the Gyres. Upon a cylinder were drawn parallel lines at the uniform distance of 1 em.: one side of the cylinder was then photographed, and the fig- ure is a reproduction of the photograph, reduced one-half. The reduction of the intervals according to the distance of the lines from the part nearest the eye illustrates the fact, not always dis- tinctly recognized, that the fissures near the periphery of a cerebral convexity always appear to be nearer together than they really are; the intervening gyres consequently appear of less than their actual width; see, for example, the superfrontal gyre in Figs. 762 and 764. possibly be correlated with the caudatum (Fig. 716); the callosal and occipital are total fissures in the fetus (Figs. superfrontal f. precentral f. (?) supercentral f. inflected f. .- precuneal f. Fic. 764.—Dorso-Cephalic Aspect of the Left Hemicerebrum of a Mu- latto; 322. »%.8. 1. Caudal radius of the triradiate supercentral fissure; 2, strait between the central and supercentral fissures; 3, caudal end of paracentral fissure (see Fig. 766) ; 4, cephalic end of the same (?); 5, Sylvian fissure; 6, postcentral fissure. See § 264. 192 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. 734 and 761), and the ental correlative of the latter is sometimes recognizable in the adult (Fig. 744). § 259. Fig. 759 illustrates: A. The mesal wall of the postcornu presents a ridge, the calcar, and the mesal sur- face of the occipital lobe a furrow, the calcarine fissure; as seen in Figs. 760 and 761, the ectal depression and the ental elevation are obviously correlated. B. The precornu presents an ental elevation, the cau- datum, and a depression nearly opposite, the Sylvian fissure. But the correlation of the two is not quite clear and the conditions are complicated by the formation of the intrafissural (or intergyral) elevation called ¢nsula. C. Here, as in the postcornu, there is no doubt respect- ing the correlation of the ental elevation or colliculus, the gououtmoid [ey1q410 n (+) orbital f. 3 Ifactory f. . | ¢ olfactory f. ..L: Ee olfactory tract . - Es rr optic nerve , - y! chiasma - optic tract .- - : 3 — postrhinal. bs B SS z collateral f. =, ® B b=) 6 splenium 3 ad ealearinef, -. Fig. 765.—Ventral Aspect of the Left Hemicerebrum of an Adult Male Mulatto; 322. X.8. 1, Ridge ventrad of the splenium, represent- ing, perhaps, one of the gyres described by A. Retzius, British As- sociation Proccedings, 1885; 2, stem of the occipital and calcarine fissures. See § 265. Preparation.—See Fig. 757. The olfactory bulb has been re- moved. hippocamp, and the ectal furrow, the hippocampal fissure; in addition, the proper nervous parietes are abrogated along a line, the rima, and the paraplexus is formed by the intrusion of the pial process covered by the endyma; the margins of the rima are specialized and become the fimbria and tenia; on the figure the tenia is not indicated as separate from the caudatum (Fig. 730). § 260. Classification of the Permanent Fisswres.—The following grouping of the fissures is approximately nat- ural and has been found convenient by me; at the best, however, any such arrangements are provisional : * * Whatever may be desirable in theory, or eventually practicable, at present nothing seems to be gained by attempting to classify cerebral depressions as fissures and sulci, and in this article all are designated as fissures. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, A. Total fissures, representing a corrugation of the entire paracelian parietes; ¢.g., calcarine. B. Partial fissures with some structural correlative; é.g., olfactory. C. Partial fissures, nearly or quite constant, and de- marcating recognized gyres; e.g., subfrontal. D. Inconstant, intragyral fissures; e.g., medifrontal. § 261. Mg. 761, inaddition to A and B, specified under Fig. 727, illustrates: A. The contiguity of the two margins ‘of the rima, excepting for the intruded para- plexus. B. The concomitant, absolute exclusion of the thalamus from the paracelian floor. C. The depth and peculiar form of the lambdoidal fissure (Fig. 750). § 262. Hig. 762 illustrates: A. The form of this adult, mulatto, left hemicerebrum, unaltered save from alco- holic shrinkage. B. The general aspect of the gyres, comparable with the appearance in the cerebrum of the philosopher, Chauncey Wright (Fig. 788). C. Asimple, almost typical condition of certain fissures, é.g.. central and Sylvian, in a large part of their course, combined with great and unusual peculiarities of the same or other fissures. D. The visibility of the insula (see Figs. 767 and 788). E. The presence of a vertical branch of the presylvian fissure, which, however, does not extend through the thickness of the operculum. F. The union of the subfrontal with the precentral and with two of the fissures crossing the medifrontal gyre. G. The apparent narrowness of the superfrontal gyre, which nevertheless, as seen from the dorsal aspect, is of considerable width; in fact the narrowest portion of the superfrontal is just as wide as is the subfrontal measured in line with the stem of the presylvian fissure; this is a forcible exemplification of what is explained under Figs. 763 and 764. H. The great length of the supertemporal fissure, and its apparent dorsal branching in four directions; its true and deep continuation is cephalad between 5 and 10. I. The continuation of the calcarine fissure around the margin of the hemicerebrum so as to appear upon the caudo-lateral aspect as an undivided end (15); the calcar- ine is believed to be continuous commonly with a bifur- cated postcalcarine, and the condition in this brain seems to be unusual; see also Fig. 785. J. The superficial connection of the central and pre- central fissures. K. The partial appearance of the subtemporal fissure on the lateral aspect; see, however, Fig. 765. L. The forking of the Sylvian into an episylvian fissure, near 4, and a hyposylvian near 5. § 263. The apparent width of gyres upon convex sur- faces of the cerebrum is affected by the point of view. Compare, e¢.g., the superfrontal gyre of the mulatto as shown in Figs. 762and 764. The conditions are schemat- ically illustrated in Fig. 763. § 264. Mig. 764 tllustrates: A. The length and inde- pendence of the superfrontal fissure, and its close paral- lelism with the hemicerebral margin. B. The width of the supercentral gyre when viewed directly as compared with the oblique view shown in Fig. 762 (see § 262, G). C. The triradiate form of the supercentral and its rela- tion to the inflected. D. The continuity of the supercentral with the pre- central and central; in each case, however, there is a vadum or shallow. § 265. Fig. 765 illustrates: A. The presence of a dis- tinct though rounded orbital prominence between the frontal and the lateral portions of the outlines, but the absence of any such boundary between the lateral out- line and the occipital. B. The narrowness of the olfactory gyre, between the olfactory fissure and the mesal margin of the frontal lobe. C. The distinctly zy gal form of the orbital fissure. Vou. IL—i3 D. The length and distinctness of the subtemporal fissure. E. The extension of the calcarine fissure upon the oc- cipital end of the hemicerebrum. F. The presence of a fissure (orbito-frontal?) on the orbital surface cephalad of the orbital fissure. § 266. List or ParriaL FissurEs, CONSTANT OR NEARLY S0, AND DEMARCATING GYRES. Fissures. Aspect. Gyres separated by them. 1. Basisylvian....| Ventral ‘Ventral } Tonporal, a. Central... <6 Lateral ; Sareea al 8. Circuminsular .| Lateral i Alois 4, Inflected.......| Lateral {| Puperfrontal. De insular... ana. Lateral Insular. 6. Olfactory......| Ventral ee is Orbital vance Ventral ae 8. Orbito-frontal..| Lateral i Ae akon 9. Paracentral....| Mesal ere ne 10. Parietal... 22... Lateral i Aeeetal 11. Paroccipital ...| Lateral i tant ei 12. Postcentral....| Lateral ee ae 13. Postrhinal..... Mesal | Tee 14. Precentral..... Lateral Eien 15. Presylvian ....| Lateral Dee ate 16. Subcentral ....| Lateral ape as 17. Subfrontal ....} Lateral i Sa tenet 18. Subsylvian....} Lateral EA te 19. Supercallosal..| Mesal ; Pai aarrea 20. Supercentral...| Lateral ; cee pie medifrontal. 21. Superfrontal. ..)| Lateral ; eae 22. Supertemporal.| Lateral eS 23. Transinsular...| Lateral Ae § 267.—Lisr oF INconsTanr Fissures, GYRES IN Wuicu Tury Occur. WITH THE Fissures. Gyres. (EA COCCIDILal ere aimee Precuneus. Dap Lu DIS Vil Vilar rae ercrererereye Subparietal. ae XOCCID ITA neeretrert estore Occipital (?). 4, Fronto-marginal ......... Fronto-marginal. Da -Hy posyaw latin mas ert eas Supertemporal. Gx Intermedial *i;, 208 Keane Subparietal. 7%. Intraparacentral ......... Paracentral. Si Medifrontelaenniteeeics Medifrontal. OP AROStGd CANO Nee tere ce cists Occipital (?). TO Postcuned erecta sce tele « Occipital (?). 11. Postoccipital fovea....... Occipital (?). 12. Postparoccipital ......... Paroccipital. L337 Precuneai noosa. oh; wants Precuneus. 193 Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain. 14. Preoccipital fovea........ Subtemporal. Lb Preparocelpital creates Paroccipital. LOS Rostralis seeks wales Callosal. Ae SUVOCCIPI Lalit sie ... Occipital (?). 18; Subtemporal......0...... Medi- and subtemporal. 10° Transtem poral aaeceen aate Meditemporal. paracentral f. (?) inflected f. ‘central f. fronto-marginal f.,. 99558 SN occipital f. supercallosal f. 6% p Dara- Y, as mcentral gh < callosal f. eB “~— £ esi. er : ) Ny CALLOSAL G. ff ' PRECUNEUS nN Qe ~ olfactory f. postrhinal f. calearine f. collateral f. subcollateral g. oa hippo- hippocampal f. campal g. Fic. 766.—Mesal Aspect of the Left (Reversed So as to Appear the Right) Hemicerebrum of an Adult Male Mulatto ; 322. xX .5. 1, The common stem of the occipital and calcarine; 2, uncus; 3, optic tract, divided obliquely ; 4, fornix; 5, retreating ventral surface of the fornix ; 6, paracentral fissure. There can be no doubt that 6 is the caudal or main portion of the paracentral, but the cephalic portion so named is thought by E. A. Spitzka to represent the intraparacen- tral, the true cephalic limb being absent. Mr. Spitzka concludes (1900) that the inflected, like the central, typically indents the mar- gin of the paracentral gyre. Unfortunately, at this time, I cannot determine the point by re-examination of the specimen; but the need of doing so exemplifies the remark in § 253. Preparation.—See Fig. 757. Defects.—Most of the fissure lines are too faint ; the emargination of the ventral outline just cephalad of the optic nerve is too decided. § 268. Mig. 766 illustrates: A. The existence and un- usual extent of the fronto-marginal fissure. B. The complexity of the precuneal fissure. C. The length of the collateral fissure. inflected f. supercentral f. ___ precentral f. -_...——-, superfrontal f. ,~—— subfrontal f.—— f presylvian f.- 2 3 presylvian f. Posse so See Taking all things into account, the central fissure de- mands first and fullest consideration; there is, indeed, no fact concerning it that is not worth recording or that may not prove significant morphologically or practically valuable. The order in which the following topics are presented is far from perfect, but it may serve to indicate the many-sidedness of these cerebral features. To save space the pronoun 7¢ will commonly designate the cen- tral fissure. * § 270. The Name.—It has been called, to use the Latin. forms, fissura, scissura, and sulcus, with the qualifying adjectives centralis, Rolandica, and postero-partetalis, all these having, of course, appropriate equivalents in the various modern languages. My doubts as to the utility of discriminating, at present, between fissures and sulci have been expressed in § 260, note. My reasons for pre- ferring central to Rolandic have been stated upon several occasions since 1882; but as the former name has now been adopted by the Association of American Anatomists and the Anatomische Gesellschaft it will probably super- sede the latter with anatomists of other nations. § 271. General Location and Direction.—On the dorso- lateral aspect of the cerebrum, at about the middle of its. length; from a point at or near the dorsi-mesal margin, it extends latero-cephalad at an angle of about 70 degrees with the meson, or about 140 degrees with its opposite. § 272. Dimensions.—Among adult hemicerebrums in the museum of Cornell University the length of the fissure, measured in a straight line between the two ends, varies from 8 to 10.5 cm., the usual length being about 9.5 em., or about one-fourth of the entire circumference of a cerebrum as measured in a dorso-ventral plane inter- secting the fissure at about the middle of its length. If measured along the sinuosities, as if the fissure were straightened out, the length may be one-seventh greater: than if measured across the curves. The greatest depth varies from 10 to 15 mm. § 273. Relation to Ental Elevations.—There is no evi- dence of any special collocation between it and any ental elevation, in man or any other mammal; hence, though: so deep, it is not a total but a partial fissure (§ 258, A). § 274. Constancy.—The only case of absence of the central fissure known to me is that described by Sir Wil- liam Turner (Jour. Anat. and Physiol., XXv., 327-848). ne a a baa ie = 22 = postcentral f. _u—=<=--" parietal f. ==—— subcentral f. er Seld —— ae —- supertemporal f. paroccipital f. ee 8 -——-—— — a =e ee en Fia. 767.—Lateral Aspect of the Left Hemicerebrum of an Adult Swedish Carpenter, Presenting an Unusual Degree of Fissuration ; 318. < .6—. Pre paration.—The hemicerebrum was hardened resting upon the mesal surface, and apparently with little change in form. The right was likewise numerously fissured. Of the unidentified fissures the only ones that seem to call for comment here are 9 and 10, which are transtemporal fissures, and 16, a well-marked hyposylvian. See § 275. D. The distinctness of the postrhinal fissure. E. An apparent peculiarity of the paracentral fissure as stated briefly in the description; the subject is dis- cussed by E. A. Spitzka, 1900. § 269. Pre-Eminent Importance of the Central Fissure. — 194 The subject was an epileptic, twenty-six years old, and the entire (alcoholic) brain weighed 1,107 gm. (393 ounces) ; a The pas fissure is quite fully discussed by Cunningham (1892, chap. iii.). REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, the left hemicerebrum 530 gm., the right 437. The left fissures are stated to have had a normal development and arrangement, but on the right the Sylvian fissure was superfrontal f. precentral f. supercentral f. medifrontal f. subfrontalf. —_ presylvian f. central f.—V Sylvian f. Fie. 768.—The Left Hemicerebrum of a Philosopher (Chauncey Wright), from the Dorso-Lateral Aspect. termediate caudal convexity. In most adults it is cer- tainly more or less serpentine or tortuous, and the regular curves are sometimes distinct; but three cephalic con- central f.—D postcentral f. parietal f. paroccipital f. occipital f supertemporal f. xX 2%. Preparation.—See Fig. 788. The figure is based upon a photograph taken as nearly as possible at an angle of 45° with the meson, so as to present the dorso-lateral aspect. The line connecting the superfrontal and medifrontal fissures was made inadvertently. The numerals | to 22 are at the same points as in Fig. 788; on that figure 23 designated the central isthmus, which here has the word printed upon it; 33 is just at the end of the short inflected fissure. wide open so as to expose the insula largely; the central Jissure was wholly absent, together with the precentral and postcentral; the lateral surface presented three arched fissures, demarcating four arched gyres about the Sylvian fissure, a condition analogous to that in the dog and many other carnivora. The interest and importance at- taching to this case would have warranted a larger num- ber of better figures, and a representation of the left hemicerebrum. § 275. Fig. 767 tllustrates: A. The unusual number of minor fissures, especially of the slight depressions which I have called fossule. B. The three cephalic curves of the central fissure, and their decided character. C. The extent of the supertemporal fissure. D. The continuity of the postcentral, parietal, and paroccipital fissures. E. The length of the dorsal branch of the presylvian. F. The two dorsal branches of the Sylvian, and the distinct hyposylvian branch (16). G. The crossing of the temporal lobe ventrad of the supertemporal fissure by two transtemporal fissures. H. The non-union of the subfrontal with the precen- tral; this last is not named but is the ventral continuation of the supercentral, beginning about opposite the sub- frontal. I. The continuity of the postcentral, subcentral, pa- rietal, and paroccipital, constituting what has been called the “intraparietal complex”; § 306. § 276. Topographical Importance.—This is well indi- cated in the following vigorous declarations of Wagner and Ecker: “ Man muss sie immer zuerst aufsuchen, wm sich von da in dem scheinbaren Chaos der Hirnwindungen. .. .”. “ Bildet sie die den sichersten Ausgangspunkt fiir die Aufsuchung der Windungen. . . .” § 277. Form, or Course in Detail.—According to Broca it normally presents two cephalic convexities with an in- a vexities have been observed in sufficient number to show the need of careful observation and tabulation. § 278. Branches.—Offshoots from the central are usu- ally rather short and straight, starting at the summits of the curves; but in the brain presenting the most decided curvatures (Fig. 767) there is scarcely any branching. § 279. Mig. 768 illustrates: A. The unfamiliar appear- ance of a hemicerebrum when viewed from this oblique aspect. B. The distinctness of the angles between the cephalic and the dorsal and ventral outlines; -this was commented upon by the first describer of this brain, Prof. Thomas Dwight, and appears in Fig. 788, though less markedly. C. The completeness and width of the isthmus between the dorsal and ventral portions of the central fissure; in Fig. 788 this is marked 28, but is so much foreshortened as to be hardly visible. D. The simple, curved form of the dorsal part of the central fissure, with no bifurcation such as exists at both ends of the ventral portion. E. The independence of the supercentral fissure. F. The presence of a medifrontal fissure subdividing the large area between the subfrontal and superfrontal fissures. G. The junction of the subcentral fissure with the parietal, and the continuity of the parietal with the par- occipital; whether this junction occurs at 1 or at 2 can- not be determined at present. H. The great length of the supertemporal fissure and the complexity of its dorsal end. I. The presence of a long and curved fissure, 6-7, on the lateral aspect of the occipital lobe. J. The presence of an unusual crescentic fissure (14) ventrad of the subcentral (15). § 280. Junctions.—So far as 1am aware, connections between the central and other fissures (excepting the in- tercerebral, § 236) are rare, and incomplete or shallow 195 Brain, Brain. when they occur; ¢.g., in Fig. 762, where the concealed vadum between the central branch and the supercentral nearly reaches the surface, and in Fig. 767, where there is also a nearly invisible vadum just at the apparent union of the supercentral with the central. The occasional confluence of the cen- tral with the Sylvian over the margin of the operculum is commonly shallow, but sometimes quite deep, as in the right hemicerebrum of James Burk, figured by Mills (Journal of Nervous and Mental Disease, vol. xiii., Septem- ber, 1886). The depth of such straits should always be stated. § 281. Bifurcation.—Terminal divis- ion of the central fissure at either end is rare; among the few cases known to me the ventral end is bifurcated on the right in a supposed insane person (885) and the ventral on the left of Chauncey Wright (Fig. 768); the dor- sal end is bifurcated on both sides in Professor Oliver (Fig. 664). § 282. Relation to the Mesal Aspect.— Cunningham found (1892, 162) that the fissure indented the dorsal margin so as to appear on the mesal aspect (as in Fig. 757) in sixty per cent. of the hemi- spheres examined. My own observa- tions would make the proportion some- what larger. For the final determi- nation of the ratio there should be employed only adult specimens retain- ing their natural form. § 283. Special Location.—About mid- way between a line coinciding with the precentral and supercentral fissures cephalad, and a line coinciding with the postcentral and subcentral caudad. § 284. How to Distinguish from Ad- joining Fisswres.*—When the precentral is separate from the supercentral, and the postcentral from the subcen- tral, the central is notably longer than either. When these two pairs of fissures unite, however, it is the mid- was cut from the dorso-mesal region of the hemicerebrum by an incision at about 45° with the meson; the pieces rest upon the oblique cut surfaces and the dorso- mesal margins correspond approximately to lines between the two Ds and the two Ms. 1, Dorsal outcrop of the cephalic end of the paracentral, which is also continu- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tion. The following characters should be noted in case of doubt: its greater depth and length; its location relatively to the entire length of the cerebrum, and the angle it forms with the margin; its more complete superfrontal supercentral precentral central (d.) central (y.) postcentral paracentral parietal isthmus paroe. incision EN paroccipital occipital Fig. 770.—Dorsum of the Cerebrum of Chauncey Wright, a Philosophie Writer, Critic, and Mathematician (see description of Fig. 788). was inadvertently tilted a little to the left. bers correspond to those on Figs. 768, 779, and 788. x .8. When photographed the cerebrum I, Central isthmus on either side; the num- independence; the usual absence of terminal forks; par- ticularly its extension to or across the dorsal margin just cephalad of the paracentral, thus indenting the paracentral gyre (Fig. 769). § 285. Alleged Duplication.—Calori and Giacomini have each described (1884) a brain which they interpreted as having two central fissures nearly parallel and separated by an “intercentral” gyre. The conditions in an educated suicide (8129) were similarly interpreted by me (1894, a); but a later comparison with a larger num- ber of brains leads me to conclude rather (1900, a) that the supposed second or cau- dal central is really an unusually long resultant of the union of the postcentral and subcentral, caudad of which is the parietal. The bifurcated dorsal end of the postcentral has the usual relation with the paracentral as it crosses the meson (see Fig. 769).* § 286. Hig. 769 illustrates : A. The more usual relation of the central fissure to the dorsal margin, crossing it so as to appear on the mesal aspect. B. The constant relation of the central supercentral precentral central postcentral ~ paracentral ous with the supercallosal; 2, a crescentic fissure which, in the foreshortened posi- tion of the parts, appears to join the paracentral, but is really separated from it by a vadum barely below the surface; 3, a similar fissure on the right, separated by a complete isthmus from the paracentral, which latter has no dorsal outcrop, but is continuous with the supercallosal; in the light of E. A. Spitzka’s observations 2 and 3 may be the inflected fissures. dle of the group of three fissures at about the middle of the hemicerebrum having a general dorso-ventral direc- * The macroscopic methods here enumerated might require confir- mation from the histology of the region in question, as indicated in the discussion of my paper, 1900, a, by Donaldson, Spiller, and Mayer (Jour. Nery. and Mental Disease, October, 1900, 540). 196 * After the above paragraph was in type the kindness of Dr. D. 8. Lamb enabled me to ob- tain a transcript of the ‘‘Nota preventiva’’ of C. Leggiardi-Laura (Archiv di Psich. Sci. Penol. ed Antrop. Crimin., Torino, 1899, p. 421), ** Du- plicita della scissura di Rolando nei criminali.” It is there claimed that among thirty-seven female brains cen- tral reduplication occurred once, on the left, and among thirty males, twice on the left, once on the right, and once on both sides. In the absence of figures, especially photographs, and detailed descriptions, I must refer these to the same category as my Own; see also the remark of Dr. C. K. Mills upon my paper (1900, a) in Jour. Nery. and Mental Disease, October, 1900, pp. 537-541, and my later note on the subject, 1900, x. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. fissure to the paracentral, the former directed at the concavity of the latter. C. The usual relations of the paracentral and postcen- tral fissures, the former directed at the reentrant angle formed by the bifurcation of the latter. D. The not unusual bifurcation of the supercentral (upper precentral) fissures. E. The asymmetry of the paracentral in respect to a dorsal outcrop of the cephalic end. F. The danger of depending upon appearances in re- spect to the independent fissures 2 and 3. § 287. Interruption.—As shown in Figs. 770 and 771, the central fissure is completely interrupted on both sides of the brain of Chauncey Wright, the isthmus* being fully on a level with the adjacent gyres. The brain of Dr. Fuchs, figured by Wagner, exhibited a like pecu- liarity, and the complete interruption has now been re- corded for perhaps fifteen hemicerebrums, a very small proportion of the enormous number examined. The left central is completely interrupted in the educated suicide (3,129) referred to in § 285; but the right is continuous. § 288. Fig. 770 illustrates: A. The unusual square- ness of the frontal outline. B. The unusual length of the region caudad of the central fissures, and concomitantly that of the parietal fissure. C. The width and simplicity of most of the gyrts, especially as compared with those of Professor Oliver (Fig. 664). D. The complete interruption of both central fissures by an isthmus, (Fig. 771). E. The lack of symmetry of the central fissures in re- spect to (a) distance of the isthmus from the meson, (0) difference in form of the dorsal portions; (¢) unlike dorsal terminations of the ventral portions. F. The unusual depth of both paracentral fissures and their non-oppositeness. G. The unusually caudal location of the right para- central so as to embrace the dorsal end of the postcentral as if the latter were the central. H. The asymmetric condition of many other fissures. I. The unequal depths of the occipitals; the right ex- tends barely beyond the ‘rounded cerebral margin; the left is at least three times as deep; this fact has been as- certained since the publication of the diagram of the paroccipital region in the Proceedings of the Ass’n Amer. Anatomists, 1895. J. The details of the paroccipital region are considered under Fig. 779. In certain respects this brain is unique and merits extended monographic treatment; but this also will be easier and more instructive when a normal standard has been more nearly obtained.+ § 289. Partial Interruption. — Several writers have called attention to the not infrequent presence of a vadum Fic. 771.—Central Region of the Dorsum of the Cerebrum of Chaun- cey Wright (Fig. 770), showing only the interrupted central fissures and the isthmuses; on the left the two portions of the fissure are designated by V and D respectively. 5. or shallow in the depths of the central fissure, commonly nearer the dorsal end; among 1,087 hemicerebrums ex- * This term is equivalent to pli de passage, annectent convolution, and bridging convolution ; the latter is misleading, for the interrup- tion of a fissure has no analogy with a bridge, but rather with a dam, dike, or isthmus, absolute size being of no moment. +The need of an improved standard for the study of fissures is clearly recognized by Mickle, 1895, opening paragraph. Brain, Brain, amined, Heschl found in 152 (about fourteen per cent.) an elevation (vadum) rising from one-sixth to five-sixths of the entire depth of the fissure, and suggests that the rare central central (y.) postcentral vadum parietal central (d.) postcentral occipital Fig. 772.—Dorsum of the Cerebrum of a Fetus Supposed to be Six Months Advanced; 2,972. 1. One of twins, both males, stillborn. cases of complete interruption result from the greater development of this feature. In view of these observa- tions the vadum should always be looked for.* § 290. Mode of Tormation.—In at least three specimens in the Cornell hiuseum, viz., 827 (Fig. 773), 2,278 (Fig. Fic. 773.—Diagrams of the Right and Left Central Fissure Regions of a Fetus, 56 cm. Long and Estimated at Twenty Weeks; 827. X 2. 752) and 2,972 (Fig. 772) there are evidences that the cen- tral begins in at least two portions, a dorsal and a ventral. Cunningham’s views are summarized thus in 1897, a, 598: “1. The typical mode of development is in two more or less distinct pieces. 2. Judging from the specimens in my possession this would likewise appear to be the more usual mode.” + The cases of partial (by vadums) or total (by isthmuses) interruption in the adult may be re- garded as retentions of the (usual or not infrequent) fetal condition. § 291. Mig. 772 tllustrates: A. The unsymmetrical de- velopment of the central, postcentral, and parietal fis- sures. B. The representation of the right central fissure by a longer ventral portion; a dorsal portion which is merely a dimple, but perfectly distinct; and an intervening vadum. § 292. Mig. 773 tllustrates: A. The interrupted con- dition cf both central fissures at their first formation. B. The lack of symmetry; on the right are two parts, the right ventral (V) being 2 mm. deep at its middle and the dorsal (D) 2.5 mm.; on the left are three distinct divisions—the dorsal parallel with the meson, the lateral at right angles with it, and the ventral oblique. § 2938. Time of First Appearance.—Nearly all writers * The morphological and zoological significance of vadums is forci- bly stated by Cunningham (1897, a, 593): ‘A close study of the me- moir of Retzius (1897) has left on my mind the impression that he somewhat understates their morphological value. With Eberstaller I hold that they constitute one of the great and distinctive characters of the human brain.” + The distinction between “ typical” and ‘‘ usual” in a case like this is not apparent. 197 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. state that the central fissure is formed about the end of the fifth month, the twentieth week. The following ob- servations show that there is probably some variation in this respect, or—as is perhaps equally probable—that the length of the fetus varies considerably at the same stage of fissural development. In fetuses 827 and 1,817, respectively 56 and 65 cm. long, the fissure is vague or absent; in 1,820, 61 cm. long, it is distinct and deep; in 2,278, 67 cm. long, it is well developed, and several other lateral fissures are visible. § 294. Relative Order of Appearance.—Excluding the transitory fissures (Fig. 748) and the lambdoidal (which may be transitory, Fig. 750), the central is apparently the first of the lateral fissures to be developed after the Syl- vian (Fig. 751). But some of my preparations indicate that this order may not be invariable; in 2,081 the parietal and supertemporal are more advanced than the central ; in 1,817 there is no trace of acentral, although both super- frontals are distinct. Numerous and careful observations are needed on this point. § 295. Form in the Fetus.— When first distinctly formed, the fissure line is nearly straight, with a slight cepbene convexity (Fig. 751). § 296. Provimate Cause.—There is no evidence that it depends upon the pressure of a blood-vessel. The causa- tion of fissures and of encephalic corrugations in general has been discussed by Jelgersma, Cunningham (1892), and A. J. Parker (1896), and briefly by Schiifer (1893, 162). § 297. Relation to Primitive Fisswres.—There is no good reason for regarding either of the three radiating, presumably transitory, fissures shown in Fig. 746, as the direct precursor of the central. § 298. Integrality.—For the definition of fisswral in- teger see § 305. The occasional complete interruption (§ 287), the not infrequent existence of a vadum (§ 289), and the mode of appearance in several cases (§ 290), sug- gest the possibility that the central consists really of two fissural integers, commonly connected, and comparable, perhaps, with the parietal and paroccipital (§ 306). For the present, however, it seems justifiable and certainly more convenient to regard the conditions above named as anomalous, and to treat the central as a single fissure. § 299. Lateral Variation. —Clevenger states that it is usually located farther caudad on the left side than on the right; its relations to motor areas would lead one to expect considerable lateral variation in position, direc- tion, and shape. § 800. Physiological and Surgical Relations.—Itis com- pletely surrounded by important motor areas, and its exact relations to the cranium and surface of the scalp are of great pathological and surgical importance, these matters are considered in the articles Brain, Surgery of the, and Brain: Functions of Cerebral Cortex. § 801. Psychological Relations.—Clevenger has a sug- gestive paper (Journal of Nervous and Mental Disease, April, 1880) on the ratio between the location of this fissure and the intelligence of the individual or species; although unable to admit his identification with the cru- ciate fissure of Carnivora, or to accept all his conclusions, IT regard the determination of the relative bulk of the precentral (frontal) region of the cerebrum and the post- central (occipito-parieto-temporal) region as of great im- portance in connection with the comparison between in- dividuals and species in respect to intellectual power and voluntary inhibition or self-control. § 802. Condition in Other Primates.—In the apes and in all the ordinary monkeys the fissure is readily recog- nized; e.g., in the Macacus, Fig. 787. § 303. Carnivoral Representative. —By various authors it has been homologized with the following fissures of the cat and dog: superorbital, ansata, coronal, and cru- ciate. Notwithstanding the similar relations of the cen- tral and cruciate fissures to motor areas, the question of their homology (morphological identity) must be held as yet undetermined. A clue may be furnished by the ob- servations of P. A. Fish (1899, 37) as to the collocation, in the seal (Phoca), of what seems to be the calear with the ventral portion of the splenial fissure. 198 § 804. Mig. 774 illustrates: A. The form of a perfect and typical Some rehal fissure, very symmetrical, and completely independent of the parietal, although its cephalic ramus and what seems to be an extension of the parietal overlap and approach very closely. B. The peculiar appearance of the entire hemicerebrum and of the central fissure from this point of view. Other points are commented upon under Fig. 775. § 805, Missural Integer.—This term was proposed by me (1886, ¢) to designate a fissure which is independent in inflected f..... Central i.e. ness paracentral f, .—... postcentral f...— parietal f... : . cephalic ramus cephalic stipe... __ 3 occipital £57 .scas- = ..paroccipital f. (zygon) paroccipital g..,___ caudal stipe ... —.. ..-caudal ramus a calcarine f..... Fic. 774.—Dorso-Caudal Aspect of the Right Hemicerebrum of a Child at Birth; 478. 1. This figure was published in the Jowrnal of Nervous and Mental Disease, June, 1886. Other aspects of the same brain are shown in Figs. 663, 756, and 775. some species or individuals, and deepest at or about the middle of its length, corresponding nearly with the place of its first appearance. Any marked and frequent shal- lowing of a supposed fissural integer is reason for ques- tioning its integrality, and for seeking, in other individu- als and in allied species, evidence that it really consists of two. § 806. The“ intraparietal* fissure” of Turner probably represents two fissural integers, the parietal and the paroc- cipital, because (1) in nearly half the cases examined by me there are two fissures separated by an isthmus of greater or less width; (2) when the two are continuous there is often a vadum at the point corresponding to the isthmus; (8) each of the two portions, whether separate or continuous, is usually deepest at or near its middle; (4) at their first appearance in the fetus they are always completely independent. § 307. The typical paroccipital fissure consists of (a) the zygon or bar, the first part to be formed; (0) cephalic and caudal stipes continuing the curve of the zygon about the dorsal outcrop of the occipital; (c) cephalic and caudal rami, imparting to each end the characteristic form seen in Fig. 774. The paroccipital is a typical zy gal fissure. § 308. Fig. 775 tllustrates, in addition to points seen equally well in Figs. 756, 668, and 775), the greater depth of the paroccipital zygon at the middle of its length, a fact hardly compatible with the supposition that it is only a caudal extension of the parietal, or that the caudal stipe and ramus constitute an independent fissure, the “transverse occipital” of Ecker. § 309. What Is the So-Called “ Transverse Occipital Fissure” ?—Most writers seem disposed to adopt the view * Often, but incorrectly, written interparietal. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. of Ecker that the caudal stipe and ramus of the paroc- cipital represent a “sulcus occipitalis transversus ” which unites with the longitudinal bar or zygon. None of the paroccipital g. central f. parietal f. occipital f. paroccipital f. IS HOP WMH supertemporal f. Sylvian f. 8 preinsula Fia. 775.—Dorso-Caudo-Lateral Aspect of the Right Hemicerebrum of a Child at Birth, Partly Dissected ; 478. 1. See the lateral and dor- sal aspects (Figs. 663 and 774). 1, Lateral surface of the zygal part of the paroccipital gyre ; this is, of course, pial, but the point of the V-shaped incision reaches a slightly lower level than the bottom of the fissure, occasioning the triangular cut area at the bottom ; 2, line representing the junction of the zygon with its caudal stipe ; 3, ectal line of the caudal ramus; 4, ental line of the same; 5, should have crossed the cut surface to the outcrop of the fissure marked 7 in Fig. 663 ; 6, the exoccipital fissure (?) ; 7, unidentified fissure; 8, presyl- vian fissure ; 9, postcentral fissure ; 10, gyre between the postcentral and the parietal fissures; 11, cephalic slope of the cut surface ; 12, cephalic ramus. Preparation.—By reference to the lateral aspect, Fig. 663, the paroccipital fissure will be seen to be indicated by the name itself, connected with the middle of the zygon. For the present figure a wedge-shaped piece was removed by two incisions, starting respectively at the tip of the rami and meet- ing at an obtuse angle at the exoccipital. The re- moval of this piece ex- posed the lateral aspect of the paroccipital gyre and of the gyres adjoining it cephalad and caudad; also the depth of the zygon and the two rami. specimens examined by me seems to confirm this interpretation, and I am compelled to re- gard the very interest- 24 ing condition shown by 133 Cunningham (1892, 147 Fig. 51) as simply an- omalous. Much. how- ever, remains to be 1 done in this region. § 310. Mig. 776 il- lustrates: A. The de- VW gree of fissuration at this period. B. The early condi- tion of the paroccipital fissure as a_ upsiloid (U-shaped), depressed 19 inflected f. Brain, Brain, E. The distinctness of the inflected fissures at this period. F. The difficulties of identifying fetal fissures in the condition of those upon the frontal and parietal regions of this specimen. § 311. Hig. 777 dlustrates: A. An almost schematic condition of the paroccipital fissure, simple in form and central f. postcentral f. paracentral f. 3 parietal f. paroccipital f. occipital f. lambdoidal f. (?) Fig. 777.—Dorso-Caudal Aspect of the Occipital Region of the Right Hemicerebrum of an Irishwomar., Thirty-Five Years Old, Exhibit- ing an Unusually Simple Condition of the Paroccip- ital Fissure; 38. x .8. Other aspects of this brain are shown in Figs 720 and 721. 1, Subcentral fissure, continuous with the pari- etal, but separated from the postcentral by a con- siderable isthmus; 2, the branch of the postcentral just aah (caudad of) the isthmus does not really precentral f. enter the parietal, al- though the shadow upon purer ventred f the slightly depressed nar- 6 row portion of the isthmus gives that appearance; 3, an independent fissure parallel with the postcen- tral; 4, cephalic ramus of the paroccipital ; 5, cepha- lic stipe of the same; 6, 7, caudal stipe and ramus; 8, supertemporal; 9, the triradiate termination of a fissure superficially con- tinuous with the super- temporal. The name lambdoidal is applied with considerable hesita- tion. postcentral i Sylvian f. parietal f. - ‘supertemporal f. ¢/__ paroccipital f. —— paroccipital g. wholly independent of the parietal, although the isthmus (opposite the end of the line line with lateral branches, rami. C. The independence of the paroccipital fis- sures at this period. D. The absence of any fissure closely re- sembling the “trans- -verse occipital.” Fig. 776.—Dorso-Caudal Aspect of the Brain of a Fetus Measuring 41 cm. from Heel to Bregma, and Estimated at Eight Months; 734. x 1. 11, Left in- flected fissure; 12, 13, separate portions of the left postcentral- 14, left parietal (?) ; 16, left paroccipital; 17, left supertemporal; 19, left occipital fissure. The remaining numbers indicate fissures of doubtful identity. Preparation.—The arteries were injected with starch mixture ; extravasa- tion took place at several points, especially the two following: (1) into the dorsal part of the right occipital fissure, converting it into a kind of fossa, at the bottom of which is seen the unaffected part of the fissure; (2) into the left paroccipital fissure, separating its walls to some extent. The essen- tial relations of parts are not affected. from paroccipital) is slightly depressed. B. An, unusual di- vergence of the caudal stipe (6) and ramus (7) of the paroccipital; the former again bifurcates just over the margin on the mesal aspect. 199 Brain, Brain, C. The presence of an oblique independent fissure caudad of the paroccipital suggesting the persistence of the lambdoidal of the fetus (§ 234 and Fig. 750). D. The separation of the postcentral from the subcen- tral by an isthmus, 2. E. The depth, simplicity, and cephalic trend of the occipital. § 312. Continuity of the Paroccipital with the Parietal Occurs More Frequently on the Left.—This has been noted by Ecker, Cunningham, and myself. In a recent paper (1900, a) I reported the results of the tabulation of 200 mated hemicerebrums, 7.é., from 100 individuals; all but 5 were adults, the 5 infants ranging from term to three ears, y (a) Of the 100 left, 77 present continuity of the paroc- cipital with the parietal; in 23 the two fissures are sepa- rated. Of the 100 right there is continuity in only 39 and separation in 61. (0) Of the 116 cases of continuity, 77 (66 per cent.) occur on left hemicerebrums, and only 39 (84 per cent.) on the right. Of the 84 cases of separation, 28 (28 per cent.) occur on the Jeft and 61 (72 per cent.) on the right.* § 818. Have the Combinations Any Significance with Re- spect to Age, Sex, Race, Character, or Mental Condition ? —For the purpose of testing this, the 100 individuals were grouped as in the appended Table; but the group- ing is obviously unsatisfactory. § 314. TABLE V.—PROVISIONAL AND UNSATISFACTORY GROUPING OF ONE HUNDRED INDIVIDUALS WHOSE PAROCCIPITAL FISSURES ARE KNOWN ON BoTH SIDEs. Group. | Characterization. Number. A Educated and orderly...:..0..,5..5- 10 B Ignorant or UBknO WN 250 gen cays spss x 5 50 C Insane—various degrees............. 25 D Murderers i.3.65 srk eines aso 6 5 E A TrICANS | VALIOUS SOTA ers eye see eit 5 F Infants under three years............ 5 § 315. In Table V. the ten members of Group A are as follows: Chauncey Wright; Prof. James Edward Oliver (8,334); a lawyer (2,870) and his wife (8,065); a teacher of mathematics (8,091); an educated farmer (8,350); a physician (8,581); a woman physician and ad- vocate of social reforms (3,480); a woman college student (3,416); and a dentist (8,129).* REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. § 818. Commentaries on Fig. 778 and Table VI.—AI- though I believe the number of mated hemicerebrums is larger than in any previous tabulation it is still too + parietal f. paroccipital yvadum _paroccipital isthmus -cephalic ramus cephalic stipe - occipital f. ~paroccipital g. -—-. -~ ~ paroccipital zygon ~ >> caudal ramus ~>eaudal stipe I. Left Continuity and Right Separation; 44 per cent. II. Bilateral Continuity ; 33 per cent. III. Bilateral Separation ; 17 per cent. IV. Left Separation and Right Continuity ; 6 per cent. Fic. 778.—Diagrams of the Paroccipital Fissure. § 316. Taste VI.—PERCENTAGES OF OCCURRENCE OF THE FOUR PARIETO-PAROCCIPITAL COMBINATIONS IN THE Srx Groups oF INDIVIDUALS. a ek : | L. Continuity. Group. Character. Number. | I. | R. Separation. A Educated and orderly ... B Ignorant or unknown ...| & C TR SATIOH cre mete a akeleacaiaiciets y D MUrderers: "fae cists s ciete mere E ASTIGAIIS arepesleraltterstaeleeteree F INTATMTS se eactns don stetrce as § 317. Mig. 779 illustrates: A. The complexity of this paroccipital region (compare Figs. 774 and 777). B. The narrowness of the isthmus between the paroc- cipital and the parietal. C. The extension of the fissure marked 36’, over the margin of the hemicerebrum, a feature not distinctly apparent in Fig. 770. * A somewhat different ratio existed among twenty unmated hemi- cerebrums. + This was the educated suicide mentioned in § 285; he was, how- ever, highly esteemed by others besides myself. 200 | R. and L. | Separation. R. and L. | Continuity. | L. Separation. Iv. | | R. Continuity. small for final results; especially is this the case with groups, A, D, E and F. Hence the following remarks must be regarded as suggestive rather than conclusive. § 819. Paroccipital Integrality.—Superficially there are more cases of continuity (116) than of separation (84). But when the known or presumptive vadums are taken into account the balance of evidence seems to be the other way. It is certainly more convenient to speak of the paroccipital fissure than of the “occipital” or “ posterior portion of the intraparietal complex.” § 320. Symmetry and Asymmetry.—In 33 brains there ” REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. is double continuity; in 17, double separation. In 44 there is right separation and left continuity; in 6, left separation and right continuity. In 50, therefore, the conditions are symmetrical and in the other 50 unsym- metrical. § 821. Postpartum Changes.—Condition III., bilateral separation, occurs in only 17 per cent. of the total, but Fic. 779.—The Paroccipital Region of Chauncey Wright. to those on Figs. 770 and 788. the addition of prime. cephalic ramus of the paroccipital at 2, where there is a vadum; on the right the isthmus is narrow and slightly depressed. The fissure marked 36, 37, and 38 is somewhat deep and eet from the occipital by a visible vadum ; on the right (36’) it enters the paroccipital ure. O and O’, the occipital fissures. in 40 per cent. of the five infants. So far as this small number goes there is borne out the conclusion of Cun- ningham that in many cases the union is delayed until after birth. § 822. Fig. 780 illustrates: A. The least common of the four possible combinations of the paroccipital and parietal fissures of the two sides, viz., right continuity and left separation. B. The continuity of the parietal and postcentral fissures on both sides, but with differences that are unusual and somewhat perplexing. C. The existence, on the right, of a clearly defined triangular fissure, 3. D. The unusual extension of the caudal ramus of the paroccipital, 4. E. The appearance of the trench (6) due to the pressure of an artery. § 828. Parieto-Paroccipital Combinations in Individuals.—Four different combinations are possible (Fig. 778), viz.: I. Left continuity and right separation; II. Continuity on both sides; III. Separation on both sides; IV. Left separation and right continuity. Amongst the 100 individuals tabulated (all that were accessible to me at the time), combination I. existed in 44; II. in 33; III. in 17; and LV. in only 6.* § 824. May Combination I. (Right Separa- tion and Left Continuity) be Regarded as Nor- mal?—Among the ten educated and moral whites (Group A) combination IV. does not occur (but neither does it among the five murderers). Combination I. occurs in 60 per cent. of Group A, in 48 per cent. of Group B (ignorant or unknown); in 40 per cent. of C (insane), and in 20 per cent. each of D (murderers) and E (Africans). & 825. There are many questions, general and spe- cial, that arise in connection with the paroccipital, but A * Mr. E. A. Spitzka informs me that this combination exists in the brain of Dr. Edouard Seguin. (See his papers, 1900, a, b.) On the left, the numbers correspond On the right, homologous parts have the same numbers with The left parietal fissure joins the Brain, Brain, space permits mention of only two which were briefly discussed in my paper (1900, @): (1) In tabulating should not the cases in which the vadum equals in height more than one-half the greatest depth of the “ parieto-paroc- cipital combination” be included under “separation ”? (2) What weight is to be assigned to the condition in apes and monkeys where continuity is the rule, perhaps with- out exception? The developmental conditions in other primates than man are not known. § 326. Mig. 781 illustrates: A. The location and common form of the insula. B. The existence of fissures and 51’ intervening gyres, radiating in gen- eral from its summit. C. The division of the whole by a somewhat deep fissure, the trans- insular (2), into a cephalic region, preinsula and a caudal, postinsula. § 827. Supergyres and Subgyres. —The ectal surfaces of two adjoin- ing gyres are commonly at about the same level, excepting for a marked change in the general con- tour of the cerebrum, as, ¢.g., at its several margins. But sometimes one gyre may be developed much more than its neighbor, and en- croach upon it so as to conceal it more or less completely. The covering gyre is here called a supergyre, and the covered a sub- gyre. § 328. Superfissures and Subfis- sures.—These terms are employed herein to designate the fissures which result from the formation of super- gyres and subgyres. The line of overlapping of a supergyre is a superfissure, as also is the line of junc- tion of two supergyres meeting from opposite direc- tions. Fic. 791.—Dorsal (Upper) and Ventral (Lower) Aspects of the Brain of the Hag, Bdellostoma ; 212. X 2.5. 207 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. not essentially dependent upon the relative size of the rhinocele. 5. Atrophy is not a necessary concomitant of occlu- sion. 6. Domestication, and the consequent disuse of olfac- tion as a means for procuring sustenance, may be a factor in promoting occlusion. 7. In the classifications of Broca and Turner the dog seems to hold an anomalous position, in that he gives every external evidence of macrosmatic power; but by the almost total occlusion of his rhinocele he approaches structurally the conditions found in the microsmatics. Physiologically he is macrosmatic; morphologically he is microsmatic. § 864. Precommissure. —As stated in §§ 45 and 210, this fibrous bundle, single at the meson, soon divides into a cerebral portion (pars temporalis) and an olfactory (pars olfactoria). The gross relations of the two are well shown in Fig. 792. For the microscopic arrangement of this and other fibrous constituents of the olfactory apparatus see the article Brain, Histology of the. § 365. Fig. 792 illustrates: A. The divergence of the plfuctory and aa divisions of the precommissure just laterad of the meson. B. The relatively large size of the olfactory division in the sheep. C. The large size of the rhinocele, but the narrowness of the strait connecting it with the precornu. § 366. Crista.—In the cat, adult as well as fetal, the caudal or celian aspect of the terma, between the columns of the fornix, presents (Fig. 686) a mesal hemispherical rhinocele strait precornu caudatum septum pars olfactoria precommissure “pars temporalis —& medicommissure pons cerebellum trapezium pyramid Fa. 792.—Brain of Sheep Dissected to Show the Two Divisions of the Prenoutacnres ; 2,653. x .9. Prepared by P. A. Fish. The cere- brum was cut from the ventral side in two planes meeting at about a right angle along the line indicated by the shadow just caudad of the line from the word medicommissure. The cephalic slope was then very carefully sliced to a deeper level, so as to leave the pre- commissure in relief. Unfortunately the pars olfactoria on the left (right of the picture) has since been broken, accounting for the interruption in the figure. Just within the aula may be dimly seen the crista. Compare with the medisected brain (article, Brain: Methods), and that of the cat (Fig. 686). body which is translucent when fresh. In some lower vertebrates it seems to be represented by a membranous mass. It has been observed in comparatively few forms, and its structure, connections, and significance are unde- termined. I have never seen it inadult human brains, but it is perfectly distinct in the preparation represented in 208 Fig. 793. is to be regarded as one of its constituents. § 367. Mig. 793 tllustrates: A. The presence of the crista in a child at term. B. The dorsal limitation of the aula and the two portas by the line of reflection of the endyma constituting a ripa. C. The narrowness of the body of the fornix as com- pared with that of the cat and most other mammals. D. The division of the caudo-ven- tral surface of the fornix, by the ripa mentioned under B, into an entocelian area, covered by en- dyma and forming the cephalic wall of the aula and the two portas, and an ectocelian area, Cov- ered by pia, the dorsal or fornical layer of the velum. § 368. The Word Rhinencephaton Used in Several Senses.—Some con- fusion may be avoided if it is clearly recognized that one and the same word has at least five different significations. 1. Owen applied rhinencephalon to Fic. 793.—The Crista and Adjacent Parts of a Child at Term; 4. X 1.5. Preparation. ‘—‘After | transection at about the middle of the diacele, the thal- ami were torn from their continuity with the fornix, leaving the irregular surface at and ventrad of 1. The lateral parts were then removed, as indicated in the drawing. The paraplexus was torn from If there is a rhinencephalic segment the crista the margin of the fimbria, constituting” the two olfactory bulbs and their tracts (or crura) without apparent reference to any mesal or connecting constituents. * 2. Turner pro- posed (1890) to re- the lateral part of the fornix ; the short line at the right ascends from the fimbria, crossing the intervening space, paracele. On the left the similar line begins more nearly at the middle of the fornix, and crosses first the callosum itself, and then the callosal fissure. Before photograph- ing, the crista was touched with white paint. Defects.—The brain was ill preserved, and broke apart during dissection; the shading is too heavy. gard the prosen- cephal as divided horizontally by the rhinal fissure (olfac- tory and postrhinal) into a ventral portion, the rhinence- phalon, and a dorsal, the pallium. 3. Shiifer proposed (Quain, 1898, 160) to include under rhinencephalon the remainder of the so-called “limbic lobe” (the hippocampal gyre), and the callosal or “gyrus fornicatis.” 4. His considers (1898) that the bulbs and tracts, the precribrums (“anterior perforated spaces”) and some other parts, under the name rhinencephalon, constitute one of three components of the dorsal zone of the most “anterior ” segment, which he names telencephalon. This view has been adopted by the Anatomische Gesellschaft and is indicated in the Table in the article, Brain, Devel- opment of ; see also my Table I. 5. In the report of the Committee on Anatomical Nomenclature which was adopted by the Association of the American Anatomists in 1897 (Proceedings, p. 47) the rhinencephalon was regarded as a definitive segment consisting of the olfactory bulbs and tracts and some other parts united across the meson by the pars olfactoria of the precommissure, the lateral cavities being connected * The mesal contact or coalescence of the bulbs inefrogs and toads, and (as observed by Mrs. Gage, 1895) in certain turtles and birds, is a secondary condition that has no bearing on the segmental constitution of the parts. * Since the name and notion of a “lobus limbicus”’ seem to be sometimes adopted without adequate inquiry, I cannot refrain from pointing out that, as is clear in Shifer’s diagram (Fig. 109), its alleged boundaries are not continuous in man, and I am not aware that they are in any animal. - REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, mm by the mesal aula. The other constituents of the rhin- encephal are named in Table I. (See above § 718). § 369. Commentaries on Fig. '194.—Besides facilitating the recognition of certain important parts and their rela- epiphysis thalamus cerebrum cyclopia (see Fig. 712 and the article Teratology), not only the cerebrum but also the olfactory portion of the brain may be single and mesal. A very instructive case is described and figured by Cunningham and Bennett, Royal Trish Acad. Trans., xxix., 101-122. § 871. Limits of the Rhinencephal.—These were not defined in the report adopted by the A. A. A., and cannot yet, perhaps, be deter- mined with accuracy. But as an individual I may here express the opinion that in mam- mals the caudal boundary coincides practi- cally with the origin of the medicerebral (“middle cerebral”) artery, or with the place of junction of the Sylvian fissure with the “rhinal,” including by this the olfactory and the postrhinal (amygdaline) together. This leaves the tip of the temporal lobe, the lobus hippocampi, and the whole hippocampal gyre as parts of the prosencephalic pallium, al- RS Ry RS none postoblongata though they may contain the cortical centres of s » cS the olfactory sense. In the lower mammals, Ss & the elevation sometimes called protuberantia s natiforns similarly lies caudad of the rhinen- Fic. 794.—Left Side of the Sheep’s Brain After the Removal of Portions of the Cere- brum and Cerebellum, So as to Display the Segmental Constitution of the Organ. (From ** Physiology Practicums ”’ ; compare Fig. 688.) 1, 3, Olfactory tract; 2, a part of the pallium which has not been cut; 4 (indistinct), chiasma; 5, pregeniculum (external or anterior geniculate body), distinct in man but here little more than a lateral portion of the thalamus; 6, tuber (cinereum), the slight convexity to which the hypophysis is attached; 7, medipeduncle ; 8, trapezium. The short lines on the ,surface of the olfactory bulb represent the olfactory The cut end of the left optic nerve is dotted to indicate its fibrous nerves. structure. Excepting the unshaded areas, representing cut surfaces, all the parts seen in this figure were covered by pia. Preparation.—The cerebellum is left of its natural height, but the cephalic and caudal conyexities are sliced away so as to expose the parts which are over- hung by them. The cerebrum has been cut down to the level of the thalami ; the caudal portion cut away along the oblique line of its projection over the part marked 5; the lateral portion so as to expose the part marked 3; also the cephalic projection which overhangs the olfactory bulbs. tive positions, this figure ‘well illustrates the segmental constitution of the brain, which is obscured in the entire organ by the preponderance of the cerebrum and cere- bellum. There is a series of more or less distinct masses demarcated by constrictions of greater or less depth. Admitting that there is still some doubt as to number and limits of the segments, the following assignments may be accepted provisionally: Olfactory bulbs and tracts } RHINENCEPHAL. Cerebrum | PROSENCEPHAL (fore-brain). Thalami, epiphysis, hypophysis, DIENCEPHAL chiasma, and geniculums (inter-brain). Geminums and crura } MESENCEPHAL (mid-brain). Cerebellum, pons, and preoblongata Postoblongata | METENCEPHAL (after-brain). t EPENCEPHAL (hind-brain). See the fuller Table on page 153. § 370. Is there a Rhinencephalic Segment ?—That I am at present disposed to answer this question in the affirm- ative is indicated in diagrams (Figs. 674 and 675), Tables (I. and II.), and remarks (§ 45) in the earlier part of this article; see also Figs. 790, 791, and 794. The whole sub- ject is still under discussion and likely to be for some time to come, and this is not the occasion for detailed argument. ‘There may be stated here, however, three facts that may not be familiar to all students of normal human anatomy : 1. Inthe lamprey and hag, although the olfactory bulbs are paired, the olfactory sac and nostril are single and mesal. 2. In the lancelet (Amphiozus or Branchiostoma) the olfactory bulb is single and approximately mesal, al- though, like several other organs of this peculiar verte- brate, not quite mesal. 3. In the malformation called monophthalmia or Vou. II.—14 cephalic boundary. § 3872. Postrhinal Fissure—Although re- garded as lying within the pallium and thus in the prosencephal rather than the rhinence- phal its associations are such that a few words may be added here as to its apparently differ- ent locations in man and in the lower mam- mals. In the latter both it and the olfactory fissure are visible from the lateral aspect. But in the lower monkeys the greater de- velopment of the pallium crowds them to the ventral side, and in man and apes the postrhinal fissure becomes actually mesal (Figs. 765, 766). TX. MENINGES (THE ENVELOPES OR MeEmM- BRANES OF THE BRAIN AND SPINAL CoRD),— § 373. Definitions.—Meninges is the plural of mening, from the Greek ujveyé, signifying any membrane or coating, as of the eyeball, and even the scum upon milk or wine; but, as stated by Hyrtl (“ Ono- matologia,” p. 3824), the word was restricted by Aris- totle (“ Hist. Anim.,” lib. i., cap. 16) to the coverings of the brain (and myel?), and the limitation has been since maintained. The synonyms of meninx are: Fy., méninge ; It. and Sp., meninge ; Ger., Hirnhaut. § 3874. The Three Meninges.—Nearly all anatomists recognize three chief membranous envelopes between the substance of the neuron (brain and spinal cord) and the craniospinal canal, viz.: an ental, the pia, an ectal, the dura ; an intermediate, the arachnoid. Their relative positions when the cranium is opened are indicated in Figs. 795 and 796. Properly speaking the pia pertains to the neuron, and the dura to the craniospinal canal, while the arachnoid has more or less varied relations to both the other meninges. All three present differences according to their location within the cranium or the spine, and there are transition conditions in the cephalic portion of the latter which are not yet fully made out.* § 375. The term pachymeniny (tough envelope) is sometimes used for the dura, irrespective of the recog- nition of a parietal layer of arachnoid. In like manner leptomenineg (tender envelope) is sometimes used for the pia and the commonly admitted visceral layer of arach- noid. The pathological terms, pachymeningitis and lep- tomeningitis are derived from these words. § 3876. Hig. 795 illustrates: A. The successive cov- erings of the brain, hairy scalp, periosteum, calva * The conditions of investigation of the meninges are peculiar. The pia and arachnoid are relatively delicate; they are easily torn and their attachments ruptured; they are surrounded by an unusually tough membrane, the dura, and the whole is enclosed within a case of bone, which must be sawn or otherwise forcibly opened by measures which are almost sure to rupture the pia and arachnoid. It is much to be desired that the subject be reviewed by some anatomist having the use of a mechanical bone-cutting apparatus, ¢.g., the electro-osted- tome of the late Dr. M. J. Roberts. 209 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. (calvarium) dura (ental periosteum), arachnoid, and pia. B. The shadowy appearance of a fissure covered by the piarachnoid and the sharper outline when it is re- moved (Fig. 802). C. The difficulty of separating the arachnoid from the pia; in a transection of a fissure, however, the former Fig. 795.—Outline of the Dorso-Lateral Aspect of the Left Half of the Head of an Adult Man, with the Brain Exposed in the Region of the Central Fissure; 811. X .3. Preparation.—The entire head was alinjected by continuous pressure for a week, and medisected as shown in Fig. 670. From the general region of the central fissure was removed a disc of the scalp about 6 cm. in diameter (A) ; in the centre of the area so ex- posed, a disc of the calva (calvaria, cranial vault) was removed with a trephine 2.5 em. in diameter, and the corresponding disc of dura eut out (B). The further preparation of the specimen is described under Fig. 796 ; the present outline is mainly given in order that the region may be located approximately upon the head. will be seen to pass across the fissure from gyre to gyre, while the latter, with blood-vessels, dips into the fissure as a fold (Fig. 735). D. The presence on the ental surface of the piarachnoid of a pial fold, the ruga, lying in the fissure. E. The minutely punctate aspect of the depiated cortex OAL MEM d: fi ¢ ~ => it ea a 3 4 : 4 Ww NIN \\ x Fic. 796.—The Several Coverings of the Brain Exposed as a Series of Terraces; 811. x .9. 1, The arachnoid, the ectal layer of the pi- arachnoid ; 2, a fissure, still covered by the piarachnoid ; 3, ruga, the fold of pia that has been pulled out of the fissure 6; 4, ental (pial) surface of the flap of piarachnoid everted from the surface of 5, a gyre, between fissures 2 and 6; 6, a fissure from which the ruga and adjacent piarachnoid have been removed. Preparation.—The region here included is a square of the region shown in Fig. 795. The outer line corresponds with the circle A, and the inner with circle B. The scalp was divided obliquely so as to expose a converging surface. A disc of periosteum was cut out a little smaller than the ental line of the scalp. The original trephined orifice in the calva was then enlarged with nippers, so as to leave a converging surface, the ectal circle a little smaller than the hole in the periosteum, and the ental about as much larger than the hole in the dura. Two fissures could be seen; over the caudal the piarach- noid was left undisturbed ; at the cephalic side of the dural orifice a semilunar flap was lifted and reflected so as to expose the ental sur- face and the fissure and adjoining gyres which it had covered. 210 by reason of the extraction of minute vessels entering from the pia. The ental surface of the pia, here repre- sented smooth, should have a flocculent appearance, called tomentum, from the attachment of these vessels. § 3877. Fig. 797 illustrates: A. The subcylindrical form of the myel, and the relations of the areas of alba and cinerea at this level; see the article, Spinal Cord. B. The existence of a dural sheath (theca) of the myel, independent of the periosteum, the two being united in the cranium. C. The somewhat loose adhesion of the arachnoid to the dura, leaving slight and scattered subdural spaces. D. The presence of the septum posticum at this level; it is said (Shiifer, iii., 188) to be most perfect in the cer- Fic. 797.—Transection of the Myel and Its Meninges in the ‘* Upper” Thoracic Region. (Enlarged somewhat from Key and Retzius, Taf. i., Fig. 7, after Shafer: Quain, iii., Fig. 132.) a, Dura (not the spinal periosteum, but representing the ental layer of cranial dura); b, arachnoid: ¢, septum posticum; d, e, f, trabecule in the subarach- noid space, those at f supporting the dorsal (posterior) nerve roots; g, ligamentum denticulatum; h. ventral (anterior) nerve roots, cut off; k,l, subarachnoid spaces. The pia is not designated, but may be recognized as the double outline of the myel dipping into the dorsal fissure as a narrow septum and into the ventral as a fold. Vote.—The foregoing is substantially the description in Shafer. But some of my observations lead me to suggest that the spinal, like the cranial, arachnoid comprises two layers, a dural and a pial, connected by the reflected layers of the septum posticum. This view, however, would homologize the space k, 1, with the intrarach- noid space of the cranium, and hence their free communication with the postcisterna would be difficult to explain. vical region, and more or less incomplete farther caudad.* E. The size of the subarachnoid space traversed by the spinal nerve roots, the trabecule, and the ligamentum denticulatum. F. The location of the ligamentum denticulatum at either side of themyel. This isa fibrous band connected with the pia, and reaching the dura by a triangular ex- tension in the intervals between the nerve roots; but op- posite the roots (as in this figure) it is narrower, and does not reach the dura. § 378. Dura.—This -mononym is rapidly replacing dura mater and the German harte Hirnhaut.+ As shown in Figs. 796, 799, and 804, the cranial dura is apparently a single sheet, dense, strong, fibrous, and unyielding, lining the bones and constituting their ental periosteum (endocranium). But a closer examination detects two layers, an ectal and an ental, which gradually separate in the cephalic part of the cervical region, and in the * Septicum posticum is an undesirable term, but septum dorsale might be confounded with the prolongation of the pia into the dorsal fissure of the myel. + The reduction of the polyonyms, pia mater and dura mater, to the mononyms pia and dura was urged by me twenty years ago (1880, f). The use of pia and dura, and of the natural adjectives, pial and dural, has now become quite general. The simplification has been recommended by the Association of American Anatomists _ (December 27th, 1889), by the American Association for the Advance- ment of Science, 1890 and 1892, and by the American Neurological Association, June 5th, 1896. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain. spine maintain diverse relations, the one with the canal, the other with the myel. § 879. Theca.—The ental or myelic portion of the It is spinal dura constitutes a fibrous tube, the theca. OO ce ey ee eY* we ew nee ¢ Fic. 798.—Schematic Transection of the Parietal Region of the New Born, to show the Relations of } to M (From Langdon, 1891.) falx; S, longitudinal sinus; xxx, subserous connective tissue between the dura and the ectal the Meninges to the Cerebrum and Cranium. arachnoid. Defects.*—The mesal dark area dorsad of S (the longitudinal sinus) represents the liga- mentous connection of the two parietal bones; it should be continuous with the periosteum and ectal dura. The ‘“‘subserous dura,’’ between the dura and the arachnoid, represented by the series of crosses, is made too wide in proportion. considerably longer and larger than the myel itself, and separated from the periosteum constituting the wall of the canal by venous plexuses and much areolar tissue. The cavity between the pia and the dura is occupied by cerebro-spinal fluid (neurolymph), and is divided by the curtain-like arachnoid into the spaces subdural and sub- arachnoid. Within the latter the myel, closely covered by pia, is suspended, being kept in position by a ligament on each side, ligamentum denticuiatum (Fig. 797), which fixes it at frequent intervals to its sheath, and by the roots of the spinal nerves (Fig. 797, f), which cross the space from the surface of the myel to the intervertebral foramina. § 380. Fig. 798 illustrates: A. The existence of two layers of dura in the cranium, the one corresponding with the periosteum of the spinal canal, the other with the dural sheath of the myel, Fig. 797, a. B. The existence of two layers of arachnoid—an ental or pial, and an ectal or dural. C. The propriety of regarding the so-called subdural space as an intrarachnoid space, analogous with the serous sacs in other parts of the body (see § 399). § 381. Fig. 799 dllustrates: A. The formation of a nerve root from the union of several funiculi or rootlets. B. The extension of the myelic dura upon the root at its exit from the spinal canal, to be lost in the sheath of the nerve. § 882. Hpidural Space.—In the spine, since there are two layers of dura, an ectal (periosteal) and an ental (myelic), the interval between them constitutes an epi- duralspace. In the figures this is nowhere clearly shown, but it may be represented in Fig. 797 by drawing around the present ectal outline, the myelic dura, a second at a little distance therefrom; the interval would be the epi- dural space. § 383. Two questions naturally arise in connection with the epidural space. 1. Does it communicate with the subdural space? If so, where? 2. If not, what is the source of the liquid occupying the space. and what is its nature? § 884. Fig. 800 illustrates: A. Therelation of the dura to the cranium as a complete lining of considerable thickness. *Dr. Langdon informs me that the cut does not represent the original drawing quite fairly in some respects. B. The relation of the falx (1) and falcula (13), as mesal extensions of the dura, to the tentorium (8) asa transverse extension. C. The tent-like form of the tentorium, the lateral margins coinciding approximate- ly with the long axis of the cra- nium, the intermediate portion rising toward the meson at an angle rapidly increasing from —periosteum the occiput cephalad. D. The inversion of the fal- yy" —calva cula as compared with the falx. : E. The general arrangement —dura ie of the more prominent fibres of the falx; there is a marked di- vergence or radiation from about the place of intersection of the free margins of the falx and the tentorium. F. The locations of the prin- cipal sinuses along the lines of attachment of the dural folds to one another or to the cra- nium. G. The direction of the cur- rent in the principal sinuses: in the longitudinal (2) and tentorial (6) (with the falcial) (4) toward the torcular; in the lateral (9), toward the exit in the base of the skull at the jugular vein (4), in the superpetrosal and subpetrosal (10, 11) to the lateral. The entrance of the supercerebral veins into the longi- tudinal sinus at the points indicated by the black spots in the course of the latter and at others not indicated. § 385. Tentorium.—The cerebral region of the cranium is partitioned off from the region containing the cerebel- lum by a fold of the ectal layer of the dura, which, from ‘ » | —ectal arachnoid \ = " . —intrarachnoid space ' . \ —ental arachnoid —subarachnoid space —pia C, C, Cerebrum; F, Fia. 799.—Section, Lengthwise, of a Ventral Nerve Root at Its Place of Exit from the Spinal Canal Enlarged. (From Key and Retzius, Taf. i., Fig. 10; after Shafer: Quain, iii., Fig. 128.) a, Four funic- uli uniting to constitute the root ;-b, dura refiected upon the root at its emergence through the intervertebral foramen (the periosteum is not shown) ; ¢, arachnoid ; d, reticular lamella of the arachnoid reflected upon the root (compare Fig. 797, f) ; s, subdural space s’, subarachnoid space. its arched shape, is called the tentoriwm (cerebelli), Fig 800. See also the article Brain, Circulation of. The tentorium exists in most, if not all, mammals, but not, so faras I am aware, in other vertebrates; in the carnivora it is ossified. § 386. Falz.—From the cerebral side of the tentorium extends cephalad a mesal duplicature of the dura, the 211 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. falx, well named from its sickle shape (Figs. 800 and The narrower cephalic end is attached to the erésta The distance between the free margin of ‘the falx 801). galt. Fic. 800.—Mesal Aspect of Right Half of Medisected Skull Retaining the Dura. X .5. (From Sappey, iii., Fig. 462; after Shafer: Quain, iii., Fig. 129.) adherent to adjacent parts, and their margins are easily detached, their relations are sometimes not clearly ap- preciated. But if an infant or fetal cranium be divided across the prefontanel diagonally so as to include either parietal bone and the opposite frontal, the cut edge will pre- sent three layers, viz., an ental, the dura, representing the endyma; an cctal, the pericranium, representing the pia; an intermediate, the bone, representing the nervous parietes. At the fontanel this third element is absent, and the conjoined dura and pericranium contribute a mem- branous area quite comparable with a tela and available for illustration thereof. A defect in the analogy is this: The cranial bone is of nearly uniform thick- ness, and thins out at the margin of the fontanel. But in the brain, although the immediate margins of the telas may be thin, the general parietes are com- monly very massive, and there is usually a parallel zone specially differentiated, é.g., the habena.* § 890. Mg. 801 illustrates (in addi- tion to the points mentioned under Fig. 687 and in § 66): A. The degree of re- ‘tention of the dura in this specimen is greater than with any brain ever seen or heard of by me. The brain was most skilfully removed, according to my direc- tions, by Prof. W. C. Krauss, a former student (see the article Brain: Methods). B. The existence, in the caudal three- fifths of the cerebrum, of a distinct and and the callosum increases cephalad. Defects.—As usual, there is no indication of the change that occurs at or near the foramen magnum, by which the apparently single dura of the cranium divides into a true dura related to the myel (Fig. 797) and a spinal periosteum; see, however, Shafer (Quain), iii., Fig. 182. The region of the postoccipital sinus (12) is so heavily shaded as to give the impression of its considerable width ; as shown in the original of Sappey, this sinus is no longer than the subpetrosal; according to Browning this is merely a constituent of the irregular basilar plexus of venous channels. The vein of Galen (25) here joins the tentorial sinus at an angle of about 45°; really, as shown in Fig. 801, it curves about the rounded splenium and joins at nearly a right angle. 1, Falx ; 2, longitudinal sinus; 3, concave ventral margin of falx ; 4, falcial (in- ferior longitudinal) sinus; 5, base of the falx where it joins the tentorium ; 6, ten- torial (straight) sinus or s. rectus ; 7, cephalic, narrow end of falx, a little dorsad of the crista galli to which it is attached; ventrad of the line is a frontal (air) sinus, seen also in Fig. 670; 8, right side of tentorium, sloping latero-ventrad from the at- tachment to the falx to the side of the cranium along the Jateral sinus (9) ; X, the tor- cular, the place of confluence of the two lateral sinuses, the longitudinal and the falcial ; 10, the superpetrous (superior petrosal) sinus: 11, the subpetrous (inferior petrosal) sinus ; 12, postoccipital (posterior occipital) sinus ; the arrows indicate the direction of the blood in the larger sinuses; the lateral sinus is continuous with the entojugular vein; 13, faleula (falx cerebelli); 14, optic nerve; 15, oculomotor nerve; 16, trochlearis nerve; 17, trigeminus (trifacial) nerve; 18, abducens nerve ; 19, facial and auditory nerves; 20, glosso-pharyngeal, vagus, and accessory nerves ; 21, hypoglossal nerve ; 22, 23, first and second cervical nerves ; 24, cephalic end of the ligamentum denticulatum (see Fig. 797) ; 25, union of the velar veins to constitute the vein of Galen opening into the tentorial sinus (see Fig. 801). The relations of the falx to the longitudinal and falcial sinuses are shown considerable mesal depression, contain- ing the longitudinal sinus, so that here the retreating surface of the dura is seen beyond its dorsal cut margin; pre- sumably this corresponded with a mesal thickening of the cranium. C. The distinctly sickle-shape of the mesal extension of the dura between the two hemicerebrums, whence its name fala. D. The non-correspondence of the width of the falx with the area dorsad and cephalad of the larger part of the callosum. E. The location, form, and extent of the medicisterna (césterna ambiens), the irregular space between the cerebellum, the splenium, and the geminums, roofed by the arachnoid and tentorium. F. The location, form, and extent of the ventricisterna (czsterna intercruralis), between the crura, the pons, and the tuber (tuber cine- reum), infundibulum and hypophysis. It forms a very in Figs. 800, 1; 801. § 387. Faleula.—This name (wrongly printed faleicula) Was proposed by me as a mononym for fala cerebelli, designating the mesal fold of dura which extends ventrad from the tentorium to the foramen magnum, where it bifurcates. It is vaguely shown in Figs. 800 and 801. § 388. Hontanels (Fr. fontanelles).—These are the in- tervals between the corners of the infantile parietal bones before these corners have formed sutural union with the adjacent bones. There are six fontanels, two mesal and two pairs of lateral. The lateral, at the cephalic and caudal angles of the ventral border of the parietal bone, are small, irregular, and of comparatively little interest. The two mesal fontanels are at the ends of the sagittal suture; their more common designations, anterior and posterior, may appropriately give place to prefontanel and postfontanel. § 389. Analogy of the Fontanels with the Telas.—The structure of a tela was described in § 22. But since, in mammals at least, the telas are always more or less closely 212 deep indentation of the ventral outline of the brain, cor- responding with the cranial or mesencephalic flexure (Fig. 671). It is bridged by the arachnoid, following substantially the line of the dura, and thus includes the arteries of this region. G. The location, extent, and form of the postcisterna (cisterna magna cerebello-medullaris), the interval between the dorsum of the oblongata, the cerebellum, and the ad- jacent portion of the cranium, or strictly the ectal layer of arachnoid in that region, represented by the black line marked 10 (see Figs. 806 and 807, § 408). H. The location of the metapore (foramen of Magen- die), the orifice in the metatela (tela choroidea inferior), constituting the roof of the metacele or metencephalic portion of the “fourth ventricle” (see §§ 78-88). In this *Tt is proper to add that, although this analogy between the telas and the fontanels had already occurred to me, I was reimpressed with it on listening to an admirable lecture upon the anatomy of the brain by Prof. D. K. Shute, at_ the Columbian Medical College, Washington, D. C., December 16, 1889. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, specimen its relations are complicated by the postcere- bellar artery, a loop of which lies just dorsad of it (see under Defects). I. The location of the postcerebellar artery. This is not named on the figure and is imperfectly shown. The central portion, from its origin at the vertebral, is invisi- ble here, but shows in Figs. 691 and 806. Just at the side of the metapore it turns sharply upon itself, forming a loop, somewhat as in Fig. 806; butin the present figure the peripheral portion of the artery alone is seen, and looks as if it began in the metapore. The two principal divisions are as here represented. There is apparently considerable variation in the course and subdivision of this vessel. J. The length of the longitudinal sinus, equalling nearly the greater curvature of the cerebrum; its cephalic able interval and communicate by a slender precom- municant artery. Here, however, they unite by their full width and again diverge. Q. The origin of the termatic artery from the place of junction of the two precerebrals; its course, parallel with the terma and copula, then around the genu at least to the dorsum; its short branches to the terma and adjoin- ing parts of the hemicerebral meson. R. The location of the postcerebral artery. The be- ginning of this, severed from the basilar, is represented by the circular spot between the hypophysis and the convexity of the pons. From it are seen small arteries entering the crura. For the two large vessels repre- sented in the ventricisterna, see under Defects. $ 391. Pia.—This was formerly more often called pia mater, sometimes also meninx vasculosa (Ger., diinne end was probably not quite reached. K. The presence of the falcial sinus (2) along the ventral, free margin of the falx. This is said to be often wanting. I suggest that the alleged absence of this sinus in the fetus sometimes may be due to its non-detection. L. The straight course of the tentorial sinus in line with the falcial, along the ventral margin of the caudal fifth of the falx, where the latter is continuous with the tentorium (Fig. 800, 8). The tentorial sinus is not named or otherwise designated on this figure, but in Fig. 800 it it is numbered 6; it is also called straight sinus or sinus rectus. M. The junction of the mesal longitudinal and ten- torial sinuses at the torcular (Herophili). The course of the lateral sinuses thence is indicated in Fig. 800. N. The location of the right velar vein (3) between the splenium of the callosum and the conarium, and its junction with its opposite at the point indicated by the circular spot at the edge of the splenium, just in line with the dotted line from that word. The two velar veins form the short vein of Galen. O. The brief course of the vein of Galen about the splenium, and its entrance at 4 into the tentorial sinus, at the place of continuity of the latter with the falcial when this is present. P. The location of the right precerebral artery (anterior cerebral). Branches of this are seen dorsad and cephalad of the callosum. The main trunk extends dorso-cephalad from the chiasma. The dark spot between the dotted lines leading from the words ¢er- ma and precommissure repre- sents the junction of the two precerebral arteries at the meson; in some cases they are separated by a consider- fornicommissure porta } medicommissure i Hy ? i atte 8) 1160 Gn ee Saree teats cs F / habena gentle deme ect ea OS 2 supracommissure epiphysis splenium termatic a, { Ee __Pregeminum’; --7--mesocele fs gx Postcommissure AY \ \postgeminum “G mB _Valvula *: lingula,, epicele J 9 4 ce precerebral a. / § copula’ / } / 4 eg / aula // / precommissure terma * ! by flea opticn, + { ' chiasma | ! hypophysis ~ | \ . albicans . a osteribrum ee ae SO | 4 ou i \ Se ee DOCU 5 10 metatela myel | metapore myelocele Fic. 801.—Mesal Aspect of the Right Half of the Brain of an Adult White Man; 376. X .65. 1, Auli- plexus; 2, falcial sinus; 3, right velar vein; 4, orifice of Galen’s vein into the tentorial sinus; 5, falcula or ‘“‘ cerebellar falx”’; 6, tentorial sinus; 7, uvula, a mesal division of the cerebellum; 8, tuber (“tuber cinereum”’) ; the line seems to stop at the artery, but should reach the thin floor of the diacele just caudad of the hypophysis ; 9, ventral end of the falx ; 10, cut edge of the ectal layer of the arachnoid, § 408; the line is too heayy and should be white instead of black ; at a point be- tween the lines from 6 and 7 it becomes attached to the cerebellar piarachnoid ; 11, longitudinal sinus. Preparation.—The brain was removed inthe dura. It was duly supported and injected through the basilar artery with the starch mixture containing alcohol described in the article Methods, etc. The injection caused the brain to fill the dura completely, and presumably assume its natural form. It was then hardened in alcohol and medisected. The same specimen was the basis for two figures in my paper, 1885, b, and this figure is reproduced in the work of C. K. Mills, 1897; the mesal cay- ities are shown on a larger scale in Fig. 687. Defects.—Although one of the purposes of the preparation of this figure was to indicate the relations of the dura to the brain, the word dura is omitted altogether. Fala designates its mesal extension between the halves of the cerebrum, as shown in Figs. 800 and 804. Along the longi- tudinal sinus (11) should be indicated the points of entrance of the supercerebral veins (see Fig. 800). The sinus, dorso-caudad of the cerebellum, between the torcular and the point marked 4, should be named tentorial sinus. On the precerebral artery, dorso-cephalad of the chiasma, are two orifices. The more caudal, at the root of the termatic artery, is caused by the removal of the left precerebral (see § 390, P). The more cephalic, between the lines from copula and aula, should be omitted, together with the intervening depressed area; they represent an accidental excavation of the artery. The arteries in the ventricisterna, the interval between the pons, the crura, and the tuber, are vaguely and inaccurately shown (see § 390, F). The postcerebellar artery (undesignated but lying between the lines from metapore and metatela) looks as if it begins in the metapore (see, however, § 390, H). The pia is nowhere distinctly represented. The black line marked 10 is the ectal layer of the arachnoid (see Fig. 806) ; the ental layer, in contact with the cerebellum, may be recognized ; they unite just dorsad of the line from 7. The curved white line about midway be- tween the callosum and the fornicommissure is due to an error; the surface of the hemiseptum forming the lateral wall of the pseudocele should be uniformly shaded. For other defects see Fig. 687. 213 Brain. Brain, Hirnhaut, weiche Hirnhaut ; Fr., pie-mére). It is deli- cate, fibrous, highly vascular, and intimately connected with the neuron (central nervous system), into the sub- stance of which it sends numerous nu- trient small vessels. When stripped off, these vessels commonly break at a short distance from the pia, and their number and minuteness impart to the ental surface of the membrane a floc- culent or woolly aspect, the tomentum (§ 376, E). § 392. Myelic Pia.—This is thicker and firmer than the encephalic, less vas- cular, and more closely adherent to the nervous substance. It has sometimes been called the “neurilemma of the cord.” 'T’wo layers are recognized: the ental, sometimes called ¢ntima pia, sends a fold into the ventral (“anteri- or”) fissure, and into the dorsal a la- mina not recognizable asa fold. Along the ventri-meson the pia presents a con- spicuous fibrous band, the linea splen- dens, not represented in Fig. 797. § 393. Hneephalic Pia. — According to Shiifer (Quain, iii, 186), only the ental of the two myelic layers of the pia is represented on the brain, but where and how the other layer dis- appears is not stated. The pia fol- lows all the undulations of the ence- phalic surfaces, dipping into the fissures and rimulas as folds or rugas of cor- responding depth (see Fig. 796). At the bottom of the intercerebral fissure, the mesal cleft between the dorsal por- tions of the two hemicerebrums, the pia enters the callosal fissure at either side, is then reflected, and crosses the cal- losum * § 3894. Telas and Plewuses.—For these structures of the pia see §§ 22-24. § 395. Fig. 802 illustrates: A. The different aspect of the cerebral surtace (a) before the removal of the piarach- noid or leptomeninges, as in the ceph- alic (upper) third of the figure; (0) after it has been removed completely, as in most of the caudal two-thirds; and (¢) when there remains the in- supercentral fissure central postcentral parietal paracentral Fic. 802.—Central Region of an Adult Brain, Partly Denuded of Pi- arachnoid and Exhibiting on the Right a Departure from the More Common Relation of the Postcentral and Paracentral Fissures ; 4,222. .5. 1, The caudal end of a fissure which is mostly covered by the pia; 2, a small spur of the postcentral representing the usual caudal branch, which is marked 5 on the left; 3, an undetermined fissure; 4, a triangular depression comparable, perhaps, with the expansion of 5 on the left; 6, the cephalic branch of the left post- central. trafissural fold, as in the left central and the part of the right central crossed by the line. * Since the pia is practically the ectal surface of the brain, its cut edge is not commonly represented excepting when the figure is on a very large scale; but on blackboard diagrams its vascular character may be instructively indicated by a red line. On such diagrams the endyma (‘‘ ependyma”’ or lining of the cavities) may be represented by yellow or green. 214 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. B. The usual relation of the central fissures to the paracentrals on both sides. C. The usual relation of the left paracentral fis- intercerebral fissure olfactory fissure olfactory bulb olfactory tract Sylvian fissure optic nerve entocarotid artery hypophysis oculomotor nerve ~ crural cisterna basilar artery trifacial nerve tentorial interval vertebral artery postoblongata spinal artery myel postcisterna Fig. 803. —Base of the Brain of a Man Estimated at Sixty-Five Years, Before the Removal of the Piarachnoid and Blood-Vessels ; 4,206. > .5. olfactory bulb and opposite the point where the arachnoid ceases to pass directly from one hemicerebrum to the other and is carried into the intercerebral fissure by the falx (compare Figs. 801 and 804) ; 2, cut or torn margin of the arachnoid at the crural cis- terna ; 3, an artery on the right lateral lobe (pileum) of the cerebellum, cbl.; 5, 5, indi- cate approximately the lateral boundaries of the postcisterna (Fig. 807); O., occipital lobe of the cerebrum ; 7., temporal lobe; F’., frontal lobe. 1, Between the meson and the right sure to the dorsal fork of the postcentral (compare Fig. 769). D. The iess common condition of the dorsal end of the right postcentrai, the caudal branch being short and the cephalic so long as to intrude between the central and the paracentral and render that portion of the postcentral gyre quite narrow (§ 11, D; compare Fig. 664). § 396. The Arachnoid.—The word arachnoid is derived from the Greek apéyvy (signifying either a spider or a spider’s web), and eldoc (form or likeness).* In general the arachnoid may be described as a non- vascular mem- brane, enveloping the brain and closely attached to the pia, excepting where the latter dips into the intervals be- tween the masses or into the fissuresand sulci of the cere- brum and cerebellum. These depressions are bridged, so to speak, by the arachnoid, excepting where the dural folds, falx and falcula, carry it for a certain distance into the intercerebral fissure and the interval between the cerebrum and cerebellum. Wherever the arachnoid re- mains the outlines of parts are more or less vague, as in Figs. 796, 802, and 803. § 397. Hig. 803 clustrates: A. The general aspect of the base of the brain when tirst removed from the cranium ; the outlines are less distinct than after the removal of the piarachnoid (compare Figs. 672 and 689), and certain * The open-meshed discs of the common garden spiders, Epeira, Argiope, ete., are not comparable ; rather the compact glazed sheet constructed by one of the house spiders (Tegenaria) which will hold water, or the still more substantial nest of the water spider (Argyro- netra), which is like a stationary diving-bell and retains the air placed under it against considerable pressure. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. features are wholly invisible, ¢.g., the chiasma, precrib- rum, and crura. B. The varying relations of the arachnoid to the inter- vals between the masses. For nearly half of the distance between the optic nerves and the cephalic end of the cere- brum the arachnoid crosses directly from one frontal lobe to the other so that the intercerebral fissure is barely recognizable as a slight mesal depression. But at the point indicated by 1 the fold of dura constituting the falx (Figs. 801 and 804) begins and forces the arachnoid into the depths of the fissure. The arachnoid dips slightly into the Sylvian fissure, and deeply into the interval be- tween the cerebrum and the cerebellum on account of the dural fold, tentorium (Fig. 800, 8). C. The existence of a considerable interval, the crural (“peduncular ”) cisterna just caudad of the hypophysis, between the crura and adjacent brain surfaces and the arachnoid; the latter was torn and cut in removing the brain, and the sharp artificial margin is indicated by 2. D. The existence of the postcisterna (“ cisterna magna ” or “cerebello-medullaris”) between the oblongata and the cerebellum; by blowing dorsad at either side of the ob- longata, where the arachnoid is torn, air entered the post- cisterna and it expanded so as to have a convex outline as in Fig 807; but when the photograph was taken most of the air had escaped and the extent of the cisterna is in- dicated only by the greater vagueness of the cerebellar outline as far as 5 at either side. § 398. As to details, however, our knowledge of the arachnoid is even less complete and satisfactory than that of the dura and pia, and there are direct contradictions in the accounts by different anatomists which I have as yet been unable to reconcile. As stated by Langdon (1891), Bichat described (1802, 1813) the arachnoid as a serous, shut sack, conforming in all essential particulars with the serosa of the other cavities. But most recent writers follow K®6l- liker (1860) in denying the existence of a parietal lay- er in contact with the dura, and Tuke regards (1882) even the visceral layer as merely an element of the pia. § 399. On February 17th, 1888, I made and re- corded the following ob- servation upon a child, still-born, at term, No. 2,258: In removing the parietal dura, a delicate membrane separated from it more or less easily in different localities on the Brain, Brain, inseparable in this region in the adult. At the base of the skull it is demonstrable as a separate membrane, even in the adult. To assert that the parietal layer of arachnoid is absent because its subepithelial connective tissue has fused at the vertex with the dura (connective tissue), is as incorrect as to describe the great omentum as one layer of peritoneum, because its original four layers have be- come matted and adherent.” § 401. During the preparation of the article Meninges in the first edition of the REFERENCE HANDBOOK I verified the correctness of the previous observation as to the pres- ence of an ectal or dural layer of arachnoid, and noted its reflection upon the carotid and vertebral arteries to be- come continuous, presumably, with the ental, pial, or vis- ceral layer. But no such reflection occurs at the nerve roots unless at some depth within the foramens of exit, and this point I have as yet not had time to determine. § 402. Hig. 804 illustrates: A. The relative positions of the meninges (compare Figs. 796 and 798). B. The formation of the longitudinal sinus within the substance of the dura. C. The projection of the arachnoid villi into the sinus and the parasinual spaces; see the article Pacchionian Bodies. D. The accumulation of the villi at one point, on the right, to such an extent as to cause the protrusion of the dura, and presumably a depression of the ental surface of the cranium. E. The separability of the arachnoid from the pia, leav- ing a distinct subarachnoid space increased along the fissure lines. F. The conterminousness of the arachnoid and the falx, and their separation by a distinct interval. § 408. Fig. 805 illustrates: A. The complete circum- two sides; it was observed Fic. 804.—Transection of the Dorsal, Mesal Region of the Cerebrum, to Show the Meninges and Arach- also by my colleague, Prof. 8. H. Gage.* § 400. On December 29th, 1890, Dr. Langdon’s paper (1891) was presented before the Association of American Anatomists. He records observations made upon two children, at term, and one adult. His summary is as follows: tertile Slightly enlarged. (From Key and Retzius, Taf. xxix., Fig. 4; after Shafer: Quain, iii., g. 134. Preparation.—The spinal subarachnoid space (Fig. 797, k, 1) was injected with a fine blue mass, which filled (and distended ?) the corresponding space upon the cerebrum and entered the arachnoid villi. The original figure is appropriately colored and on a larger scale. Judging from the relation be- tween the width of the falx and the interval between it and the callosum, the plane of section was not far cephalad of the splenium (see Fig. 801). c¢.c., Callosum; f, falx ; s, longitudinal sinus; s.a. (at the left), subarachnoid space. Defects.—The pia is not so distinct as I would makeit. The relation of the arachnoid to the ven- tral margin of the falx is not quite clear. There is no extension of the cortical cinerea upon the dor- sum of the callosum as an indusium (see § 217). There is no indication of the existence of the two layers of the dura, e.g., periosteal and encephalic, described by Langdon (Fig. 798). The falcial (inferior longitudinal) sinus may have been absent in this case, as it is said to be in many. The lacuncee laterales are somewhat indistinct, probably in consequence of the reduction from the original figure, where they are much more clearly shown. “The arachnoid is a true shut sac, similar in structure and function to the serosa of the other great cav- ities. Its parietal layer is easily separable from the dura at the vertex in the fetus and young infant, but practically * Although this distinctly indicated the existence of a parietal (ec- ‘tal) layer of arachnoid,’at that time I supposed the subject, Meninges, -would be treated by another, and was, moreover, then fully occupied -with the articles already undertaken ; hence the observation was not “made public and the point has not been followed up. scription of the true encephalic cavities, excepting at the metapore. B. The non-communication of these cavities with the pseudocele (fifth ventricle). C. The presence of considerable, irregular intervals, subarachnoid spaces, or cisternas, between the pia and the arachnoid. D. The continuity of the largest of these, postcisterna, 215 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. between the cerebellum, postoblongata, and occipital part branes. The editors of Quain have represented the missing meta- of the cranium, with the spinal subarachnoid space. Fig. 805.—Medisection of the Cerebellum and Adjacent Parts. (From Key and Retzius, 1875, Taf. viii., vii., Fig.1; after Shafer: Quain, iii., Fig. 131, reduced and somewhat modi- fied.) Compare Figs. 670, 800, and 801. 1, 1’, Atlas vertebra; 2, 2’, axis vertebra ; 8, diacele (third ventricle) ; 4, epicele, the cephalic or cerebellar portion of the ‘* fourth ventricle’ ; C, cerebellum ; C.C., callosum; C’, callosal gyrus; M, post- oblongata; P.V., pons; X, faleula (falx cerebelli) ; ¢, medicommissure ; ¢.c., just dorsad of (behind) the myelocele (central canal of the cord) ; f.M., metapore (°° for- amen of Magendie’’); », hypophysis ; t, torcular. Preparation.—A blue mass was inject- ed into the spinal subarachnoid space ; the head was then frozen and medisected. The original includes the mesal aspect of the entire head, less the integument and mandible. The true encephalic cavities and thesubarachnoid spaces are colored, so only the actual mesal parts appear. Defects.—In the original there is no in- dication of the arachnoid, although the circumscription of the subarachnoid space was the very feature supposed to be illus- trated. Should it be claimed that the arachnoid is sufficiently indicated by the ental boundary line of the dura, the an- swer would be that, although in places the two meninges may be in contact, they are not in all; furthermore, as distinctly shown upon Taf. vi. of the same work, in Figs. 801, 806, and 807, there is a point near the crest of the cerebellum (nearly opposite t) where the arachnoid (or its ectal layer) leaves the cerebellum and passes directly to the dura at the foramen magnum. There is no boundary between the metepicele (fourth ventricle) and the subarachnoid space; even if, as in other cases, the membranous roof of the meta- cele (metatela) adheres to the caudo-ven- tral surface of the cerebellum, the plexuses and the endyma constituting its ental surface must end somewhere. Since the cavities are not colored, they appear as white areas without perspec- tive, as if the preparation were a thin mesal slice. Most unfortunately, probably through some defect in execution, there is left a clear line between the epiphysis and the splenium, as if there were a pass- age from the diacele (third ventricle) to the irregular subarachnoid space between the splenium, epiphysis, pregeminum, and cerebellum. This is altogether misleading, for, as shown in Figs. 670, 687, 759, and 801, and stated in § 66, H, the dia- tela by the dotted line from near the number 4 to near the abbrevia- tion f.M. A continuous line would have been more appropriate, and separated farther from the metacelian fioor ; that could not be changed in the present copy, but the interval representing the meta- pore (foramen of Magendie) has been enlarged; this, however, is conventional, and as if to correspond with the perhaps unusual con- dition shown in Fig. 690. Finally, the falcula (falx cerebelli), which was unmarked in Quain, is here designated by a cross (x). mesal portion, vermis, of the cerebellum. In Fig. 707 this is obscured by the fact that part of the left lateral lobe remains. § 404. The Cisternas.—At several regions the ental layer of arachnoid is separated from the pia by consider- able spaces, called cisternas by Key and Retzius, 1875, p. 93.* They are enumerated and described by Browning. § 405. Fig. 806 illustrates: A. The general appearance of this aspect of the cerebellum together with the oblon- gata and pons; in Fig. 697 these two parts were omitted. B. The extent of the postcisterna (cisterna magna or ¢. cerebello-medullaris) upon about one-half the entire caudal aspect; there is, however, considerable variation in this respect. C. The definite dorsal and lateral limitation of the postcisterna, although the boundary line is undulating and asymmetrical. D. The lack of ventral boundary of the cisterna; the ectal layer of the arachnoid is attached to the dara so that this cisterna is continuous with the spinal subarach- noid space. : E. The union of the two vertebral arteries to form the basilar. F. The origin of the postcerebellar arteries from the vertebrals near their junction. vallis 7 postvermis 6 5 metaplexus tonsilla myel postcerebellar a.. vertebral a. basilar artery pons Fic. 806.—Caudal (Lower) Aspect of the Cerebellum, etc.; 876. xX .9. Preparation.—Through the kindness and skill of Dr. W. C. Krauss (a former student, now professor in the Medical Department of Niagara University, the brain was received fresh and in the dura. The cavities were injected with alcohol; the arteries first with al- cohol and then with the starch mixture (see article Brain: Methods). The alcohol passed through the metapore into the postcisterna and thoroughly preserved all the parietes ; it had access also about the myel, where the arachnoid was cut in removing the brain. The: ectal layer of the arachnoid was cut away along the line of its attachment. Defects.—The perspective of the postoblongata is defective. The metapore is vaguely indicated and few of the vessels are shown. Of the lobes only the tonsillas are outlined. The flocculi and nerve roots are omitted, also the rimulas (interfoliar crevices) on the left. side. The most serious defect is the non-indication of the dorsal limit of the endyma which presumably accompanies the metaplexuses ; see § 417. 1, 3, Branches of the postcerebellar artery, the former passing between the cerebellum and the oblongata, the latter apparently supplying the corresponding metaplexus ; 2, 6, edge of the ectal layer of arachnoid bounding the area whence it had been cut away ; 4, loop of postcerebellar artery, an example of its tortuous course; 5, main trunk of the artery near where it reaches the crest of the cerebellum ; its branches are omitted; 7, mesal ridge formed by the vein which divides into a right and left branch upon the caudal surface; the arachnoid here forms a somewhat sharp angle. G. The length and course of the postcerebellar artery, and the tortuous course of its central portion. ‘ cele is completely circumscribed at that point by the endyma reflect- ed from the velum upon the epiphysis. In the present copy this de- fect has been remedied so far as it could be by uniting the epiphysis and splenium so as at least to block the passage; but it should be remembered that it is closed not by nervous tissue but mem- 216 * Admitting that most of the cisternas do lie between the arachnoid and the pia, as commonly described, my later observations lead me to regard the postcisterna as between two layers of the ental arachnoid itself (see Figs. 805 and 807). REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, H. The passage of a branch of the postcerebellar artery mesad toward the metapore, apparently supplying the metaplexus, arachnoid piarachnoid prevermis {noid dura and its arach- = = 1 intrarachnoid space ee a ht ectal layer of ental arachnoid A _ posteisterna [arachnoid ental layer of ental pia parayermian sulcus postvermis | pial fold Fia. pad .—Sections of the Cerebellum and Postcisterna ; semidiagram- matic. A. Dorsal (cut) surface of the ventral portion of the cerebellum, together with the adjacent dura and the large “subarachnoid space,’ postcisterna, commonly called cisterna magna or ¢. cere- bello-medullaris. At the meson appears the postvermis, separated by the paravermian sulci (1) from the large lateral lobes; 3 is the ental layer of the arachnoid. The meninges are here represented by lines only. B. Enlargement of the meso-caudal region of A. The meninges are here represented by zones conventionally shaded ; 2, the place of junction of the two layers of the ental arachnoid at the margin of the postcisterna. Preparation.—An adult cerebellum (2,891) was divided at a plane corresponding with the line X—Y in Fig. 806, so as to separate the dorsal two-fifths ; on Fig. 801 the plane of section would be indi- cated approximately by a line across the unshaded (cut) surface connecting the points where the dotted lines from the words nodu- lus and epicele intersect the margin of that surface ; as seen in Fig. 806 it passes dorsad of the plexuses. The ectal layer of arachnoid is represented as the continuous caudal boundary of the postcisterna, while in Fig. 806 it is supposed to have been trimmed closely along the line of its depression from the ental layer 3. Defects.— For readier comparison with Fig. 806 the figures should have been inverted so as to have the postcisterna nearer the reader. In B the postcisterna is enlarged two diameters, but the several zones representing the meninges are disproportionately widened, and their shading is conyentional for discrimination only, and not for the indication of histological structure. The ectal or dural layer of arachnoid was inadvertently omitted, and there is no indication of the two layers of the dura itself. The numerous rimulas and in- tervening foliums that were divided in the section are not indicated, and the usual relations of the pia and arachnoid to each other and to narrow encephalic depressions generally are illustrated only at the parayermian sulci. According to the ,present view * that the metapore is the orifice of an evagination, the postcisterna may be lined, in part at least, by endyma; but it was not recognized in this preparation, and even in the embryo represented by Blake (1898, Fig. 26) it seems to have disappeared at a lower level. I. The extension of the metaplexuses dorsad from the metapore upon the cerebellum. § 406. Postcisterna.—Notwithstanding the presumption that all the cisternas form a continuous series, my obser- vations, up to the present time, induce me to regard the * At the time § 83 was made up into the page I was unaware that the German edition (1894) of Minot’s ‘* Embryology ”’ has this passage, p. 698: ** The foramen of Magendie (Wilder’s metapore) and the open- ings of the lateral recesses, according to this view, would be not true perforations of the ependyma, but the outlets of evaginations.”’ space in the angle between the cerebellum and the ob- longata as presenting an important peculiarity. viz., as lying, not between the pia and the visceral arachnoid, but between two layers of the latter. The facts upon which this view is based cannot be detailed here. The view is indicated upon Fig. 807. I am aware of the difficulties involved in its acceptance; without question, the postcisterna communicates on the one hand with the true encephalic cavities through the metapore, and on the other with the spinal subarachnoid space; its free communication with the other cisternas, although commonly accepted, seems to me not yet clearly demonstrated. § 407. Is there Direct Communication of the Subarach- noid Spaces with the Intrarachnoid (or Subdural) Space ?— Whatever view they adopt regarding the constitution of the arachnoid as a whole, most writers agree that the arachnoid covering the brain and myel is continuous, ex- cepting for the capillary spaces about the nerve roots re- ferred to in § 401. Hence, while the neurolymph may pass to and fro between the true encephalic cavities and the postcisterna through the metapore, and may thus enter the other cisternas (§ 406) and the spinal subarach- noid space, it is nevertheless confined thereto. But Dr. Langdon (1891) holds that “at the base of the cranium there are two points where the visceral [ental] arachnoid is deficient, one on either side, in the ‘ bridge’ of arachnoid which stretches across from the cerebellar lobes to the under [ventral] surface on the oblongata. These foramina measure about half an inch (12 mm.) in longitudinal diameter by one-fourth inch (6 mm.) trans- versely, and are crossed by three or four fibrous bands, the attachment of which to the edges of the openings produces a multiple crescentic appearance of their mar- gins, which suggests the name ‘lunulate foramina.’ ” It will be noted that the location of these alleged lunu- late foramina in the arachnoid corresponds with that of the ventral ends of the lateral recesses. Hence, on the one hand, if both are natural, the transfer of the neuro- lymph from the true encephalic cavities to the arachnoid space is provided for; on the other, the relation of the nerve roots to both the piaand the arachnoid renders both liable to rupture during extraction or manipulation of the brain. Hess implies (1885, Fig. 10, a.) that the arach- noid was cut and reflected at this point. On the whole subject, and on the metapore see the later observations of Blake, 1900. § 408. Mig. 807 tllustrates: A. The usual relation of the meninges in these respects, viz., the independence of the dura; the adhesion of the pia to the brain substance; the dipping of the pia into the narrow depression at either side of the vermis as a vascular fold; the adhesion of the arachnoid to the pia over most of the cerebellum, so as to constitute a piarachnoid (Fig. 796). B. On the caudal aspect of the cerebellum, the forma- tion of a considerable space, the postcisterna, by the separation of an ectal layer of the ental or visceral layer of the arachnoid. § 409. The inadequacy of the foregoing account of the postcisterna and its relations with the metapore is fully conceded. It is no disparagement to the labors of Blake and others to add that no account known to me is alto- gether clear, consistent, correct, and complete. The dif- ficulties involved can be fully appreciated only by those who have already attempted to elucidate the subject. The material must be specially prepared for the purpose and examined by improved methods, both anatomical and histological. Burt G. WILDER. § 410. The following list includes treatises upon the gross anatomy of the brain, mostly recent, likewise a few special papers ; other papers are named in the text. Other things being equal, preference is given to such as contain full bibliographies. The history of Neurology up to 1822 is given in Burdach. For current literature consult the Jowrnal of Comparative Neurology ; Anato- mischer Anzeiger ; Index Medicus ; Neurologisches Centrat- blatt; Brain; L’ Encéphale; Nevrdve; Jahresberichte 217 Brain, Brain, fiir Anatomie, etc. See § 12. A. A. A. Proc. stands for Proceedings of the Association of American Anatamists. BIBLIOGRAPHY. Blake, J. A., 1900: The Roof and Lateral Recesses of the Fourth Ventricle Considered Morphologically and Embryologically. Read before the Assn. Amer. Anat., December 28th, 1898. Jour. Comp. Neurol., x., 79-108, 7 plates. Broca, P., 1888: Mémoires sur le cerveau de ’homme et des pri- mates, O. Burckhardt, R., 1895: Der Bauplan des Wirbelthiergehirns. logische Arbeiten, iv., 181-150, taf. viii., 1895. Burdach, K. F., 1822: Vom Baue und Leben des Gehirns, Q., 3 vols. Clark, T. E., 1896: Comparative Anatomy of the Insula. Journ. of Comp. Neurol., vi., 59-100, 5 plates. Dalton, J. C., 1885: Topographical Anatomy of the Brain, Q., 3 vols. Dana, C. L., 1893: Text-Book of Nervous Diseases; Being a Compen- dium for the Use of Students and Practitioners of Medicine, O., illustrated, New York. Dejerine, J., 1895: Anatomie des centres nerveux, R. O., 2 vols., Vol. I., pp. xiii. and 816, 401 figures. [The macroscopic anatomy occu- pies pp. 233-517 of vol. i.] Eberstaller, O., 1890: Das Stirnhirn; ein Beitrag zur Anatomie der Oberfliche des Grosshirns, O., pp. 140, with 9 figures and | plate; Wien. Edinger, L., 1896: Vorlesungen tiber den Bau der nervésen Central- organe des Menschen und der Thiere. Fifth edition, R. O., pp. 386, 258 figures, Leipsic. (See also Hall, translator, 1899.) Edinger, L. u. Wallenberg, A., 1899: Bericht tiber die Leistungen auf dem Gebiete der Anatomie des central Nervensystems. (566 titles, 1897, 1898, with commentaries.) Schmidt’s Jahrbiicher der Ge- sammte Medicin, cclxii., pp. 72. Findlay, J. W., 1899: The Choroid Plexuses of the Lateral Ventricles of the Brain, their Histology, Normal and Pathological (in relation especially to Insanity). Brain, vol. xxii., 1899, pp. 161-202; 3 plates. Fish, P. A., 1890: The Epithelium of the Brain Cavities. Amer. Soc. Micros. Proc., 140-144, 1 plate, 1890. , 1893: The Indusium of the Callosum. Journ. Comp. Neurol- ogy, iii., 61-68, 1 plate. , 1899: The Brain of the Fur Seal, Callorhinus ursinus, with a comparative description of those of Zalophus Californianus, Phoca vitulina, Ursus Americanus, and Monachus tropicalis, O., pp. 20, 4 plates. From the report on the Fur Seals and Fur-Seal Islands of the North Pacific Ocean, part iii. Flatau u. Jacobsohn, 1899: Handbuch der Anatomie u. Vergleichenden Anatomie des Centralnervensystems der Saéugetiere, I., Makro- skopischer Teil, R. O., pp. 578, 6 plates, 120 figures in text, Berlin. [Contains a good bibliography. ] . Gage, Mrs. S. P., 1895: Comparative Morphology of the Brain of the Soft-Shelled Turtle (Amyda mutica) and the English Sparrow (Passer domestica). Proc. Amer. Micros. Soc., xvii., 185-228, 5 plates. , 1896: Modifications of the Brain During Growth. Abstract of paper read before the Amer. Assn. Adv. Sci., August 24, 1896. Amer. Naturalist, xxx., 836-837, October, 1896. Gerrish, F. H. (editor and collaborator with Bevan, A. D., Keiller, W., MeMurrich, J. P., Stewart, G. D., and Woolsey, G.), 1899: A Text- Book of Anatomy by American Authors, R. O., pp. 917, 950 figures, Philadelphia and New York. Giacomini, C., 1884: Guida allo Studio delle Circonvoluzioni Cerebrali, O., Turin. Gordinier, H. C., 1899: The Gross and Minute Anatomy of the Central Nervous System, R. O., pp. 589, 48 plates and 213 figures, Philadelphia. pond, G. M., 1900: Suggestions to Medical Writers, O., pp. 180, Phila- elphia. Hall, W. S., 1899 (translator of Edinger, *‘ Vorlesungen,’’ 1896): The Anatomy of the Nervous System of Man and of Vertebrates in Gen- eral, R. O., pp. xi. and 446; 258 figures, Philadelphia. Hervé, G., 1888 : La Circonvolution de Broca, O., pp. 275, Paris. Hill, Alex., 1890 (translator and annotator of Obersteiner’s ‘‘ Anlei- tung ’’ (1887) : The Anatomy of the Central Nervous Organsin Health and in Disease, O., pp. 432, with 198 illustrations, Philadelphia, 1890. Hill, Charles, 1900: Developmental History of Primary Segments of the Vertebrate Head. Contribution from the Zool. Laboratory of the Northwestern Univ. Zodlogischer Jahrbiicher, Abt. f. Anat.gu. On- togenie der Thiere, xiii., pp. 393-446, 3 plates and 4 figures in text. [Preliminary paper in Anat. Anzeiger, 1899, 353-369]. His, W., 1895: Die anatomische Nomenclatur. Nomina anatomica, Verzeichniss der von der Anatomischen Gesellschaft auf ihrer IX. Versammlung in Basel angenommenen Namen. Eingeleitet und im Einverstindniss mit dem Redactionsausschuss erlaiitert von Wilhelm His. Archiv fiir Anatomie und Physiologie, Anat. Abth., Supplement Rand, 1895, O., pp. 180, 27 figures, 2 plates. Ibanez, G., 1899: Die Nomenclatur der Hirnwindungen. Dissertation, Berlin, pp. 37. Key u. Retzius, 1875: Studien in der Anatomie des Nervensystems, F., 2 vols., Stockholm. Krause, W. [editor], 1880: Handbuch der Menschlichen Anatomie, 3 ee O. Hanover. [A later edition, 1899, is in course of publica- tion. Langdon, F. W., 1891: The Arachnoid of the Brain (read before the Association of American Anatomists, December 29th, 1890). New York Medical Record, August 15th, 1891, 177-178, 2 figures. Mickle, W. J., 1895: Atypical and Unusual Brain Forms, especially in relation to Mental Status. Presidential address (British) Medico- Psychological Association, 1895. Brit. Med. Jour., September 28th, 1895: Journ. Ment. Sci., July, 1896 et seq. Mills, C. K., 1886: Arrested and Aberrant Development of Fissures and Gyres in the Brains of Paranoiacs, Criminals, Idiots and Negroes. Preliminary study of a Chinese brain. Presidential ad- dress, Amer. Neurol. Assoc., 1886. Journ. Nery. and Ment. Disease, xiii., September and October, 1886, pp. 37, 2 plates. 1897: The Ner- vous System and Its Diseases, R. O., pp. 1056, 459 figs., Philadelphia. 218 Morpho- Inaug. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Minot, C. 8., 1892: Human Embryology, R. O., pp. 815, 463 figures, New York. German edition, 1894. Obersteiner, H., 1896: Anleitung beim Studium des Baues der Ner- vosen Centralorgane im gesunden und kranken Zustande, third edition, O.,; pp. 572, 205 figures, Leipzig und Wien. (See also Hill, translator of second edition.) Parker, Andrew J., 1896: Morphology of the Cerebral Conyolutions with Special Reference to the Order of Primates. Journ. Acad. Nat. Sci., Philadelphia, N. S., x., Q., pp. 247, 15 plates, 31 figures in text. Parker, T. J., and Haswell, 1898: A Text-Book of Zoology, 2 vols., O., London and New York. 1900: Manual of Zoology, O., New York. Pfister, H., 1899: Ueber die occipitale Region und das Studium der Grosshirnoberfliche, O., pp. 86, 4 plates, bibliography of 108 titles. Stuttgart. [Discusses particularly the human homologue of the ** ape-fissure.”’ ] Quain, 1890-1898: See Shiéfer. Reichert, C. B., 1861: Der Bau des menschlichen Gehirns, O. Retzius, G., 1896: Das Menschenhirn: Studien in der Makrosko- pischen Morphologie, F. and Text, pp. viii. and 167, xiii. (really 141) figures. Atlas, xcvi. plates, Stockholm. Shifer, E. A., 1893: Neurology, Part i. of vol. iii. of the tenth edition of Quain’s Anatomy, edited by Shafer and Thane, London and New York, 1890-1898. Spalteholtz, W., 1900: Handatlas der Anatomie des Menschen, Mit Unterstiitzung von W. His bearbeitet., Bd. iii., Abt. 2, Gehirn. (Announced.) Spitzka, E. C., 1884: Contributions to the Anatomy of the Lemniscus. N. Y. Medical Record, xxvi., 393-397, 421-427, 449-451, 477-481, 16 figures, October and November, 1884. Spitzka, EK. A., 1900, a: The Brains of Two Distinguished Physicians, Father and Son. A Comparative Study of their Fissures and Gyres. Illustrated with 20 plates, and several figures in the text. To be read before the Association of American Anatomists, December, 1900. 1900, b: A Contribution to the Question of Fissural Integrality of the Paroccipital; observations on one hundred brains. Idem. 1900, ¢: The Mesial Relations of the Inflected Fissure ; observations on one hundred brains. Idem. 1900, d: Preliminary report, with projection drawings ilustrating the Topography of the Paraceles in their Relations to the Surface of the Cerebrum and the Cranium. Idem. Stilling, B., 1878: Neue Untersuchungen tiber den Bau des kleinen Gehirns des Menschen, etc., Q., pp. 357 and lxxviii., folio atlas of 21 plates, Cassel. : Stroud, B. B., 1895: The Mammalian Cerebellum. Part I., The De- velopment of the Cerebellum in Man and the Cat. Journ. Comp. Neurol., v. 71-118, 8 plates, 1895. 1897, a: A Preliminary Account of the Comparative Anatomy of the Cerebellum. A.A. A. Proc., May, 1897, pp. 20-27, 1 plate. 1897, b: The Morphology of the Ape Cere- bellum. A. A. A. Proc., December, 1897, 107-126, 1 plate. 1899: If an ‘‘ Isthmus Rhombencephali,”’ why not an Isthmus Prosencephali ? A. A. A. Proe., December, 1899, 27-29, 2 figures; Abstract in Science, March 16, 1900. Studnitka, F. K., 1895: Zur Anatomie der sog. Paraphyse des Wirbel- thiergehirns. Sitzungsber.der K. B6hm, Ges. Wiss. Math.-Nat. Cl., 1895, pp. 13, 1 plate. , 1899: Ueber den feineren Bau der Parietalorgane von Petromyzon marinus. Idem., 1899, pp. 17, 1 plate. Turner, Prof. Sir W., 1890: The Convolutions of the Brain. Journ. Anat. and Physiol., xxv. 1-53, 42 figures. Van Gehuchten, A., 1900: Anatomie du systéme nerveux de l’homme, 38me edition, R. O., 2 vols., pp. xxiv. and 527-579, 702 figures, Louvain. (The macroscopical anatomy occupies 186 pp. of vol. i.) Weinberg, R., 1896: Die Gehirnwindungen bei den Esten, eine anat- omisch-anthropologische Studie, Q., pp. 96, 5 double plates, Cassel. Waldeyer, W., 1896: Hirnfurchen und Hirnwindungen. [447 titles, with commentaries.] Ergebnisse der Anat. u. Entwickelungs- geschichte, 1896, 146-193. , 1899: Hirnfurchen u. Hirnwindungen. Hirnkommissuren. Hirngewicht. [190 titles, with commentaries.] Idem., 1899, 362- 401, 8 figures. Wilder, B. G., and Gage, S. H., 1892: Anatomical Technology as Applied to the Domestic Cat, third edition, from the second re- vised, O., pp. 600, 1380 figures, and 4 lith. plates (chap. x., pp. 400- 503, is devoted to the brain), New York and Chicago. Wilder, B. G., 1896, h: Neural Terms, International and National, Journ. of Comp. Neurol., vi., December, 1896, pp. 216-352, including 7 tables; Parts vii-ix. have also been reprinted under the title “Table of Neural Terms, with Comments and Bibliography.” 1897, ¢: What is the Morphologic Status of the Olfactory Region of the Brain? A. A. A. Proc., December, 1897, 94-99; Science, Febru- ary 4, 1898, vii., 150-152. 1899, a: Historic, Ethical, and Practical Considerations Respecting the Names and Numbers of the Definitive Encephalic Segments. Abstract A. A. A. Proc., December, 1899, 3-4. Science. March 16th, 1900. 1899, b: Comments upon the Figure of the Mesal Aspect of an Adult Brain as published by His and repro- duced in the B. N. A. Abstract A. A. A. Proc., 1899, Science, March 16, 1900. 1899,¢: The Basis and Nature of a Segmental Schema of the Brain. Abstract A. A. A. Proc., 1899, Science, March 16, 1900. 1899, d: Is Neuron Available as a Designation of the Central Ner- vous System? Abstract A. A. A. Proc., 1899, Science, March 16, 1900. 1900, a: Further Tabulations and Interpretations of the Paroccipital Fissures. Abstract A. A. A. Proc., 1900. 1900, b: Revised Schema of the Cerebral Fissures. Abstract A. A. A. Proc., 1900. 1900, ¢: Revised Interpretation of the Central Fissures of the Educated Suicide’s Brain which was exhibited to the (Amer. Neurol.) Asso- ciation in 1894. Journ. Nery. and Ment. Dis., October, 1900, 536-539, vol. xx. For note as to earlier titles, see § 12. BRAIN, ABSCESS OF.—Cerebral abscess is always the result of the introduction of pus-producing germs into the tissues of the brain. The organisms which are found most frequently are streptococcus pyogenes and REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. staphylococcus pyogenes aureus. Staphylococcus pyo- genes albus and citreus are also found occasionally, but are always associated with the former ones. When the pus from the brain lesion has been compared with that from the primary wound or otorrhoea, the same organisms have frequently been found in both places. Bacillus pyogenes feetidus has been found in one case in the abscess and in the discharge from the ear. Fraenkel’s diplococcus pneumoniz was obtained in a meningeal abscess which accompanied an abscess in the cerebellum. In one case the observer was unable to decide whether the germ was Eberth’s bacillus entericus or Neumann’s bacillus meningitidis purulente. In several cases pyo- genic organisms were associated with Gessard’s bacillus pyocyaneus. In two cases oidium albicans was dis- covered; in one of these the brain contained small ab- scesses which were filled with the fungus. Sabrazés reports a case of abscess of the centrum ovale, abscess of the apex of the right lung, anthracosis of the lungs and purulent softening of an infarction in the right kidney. The pus of the abscesses contained a micro-or- ganism which was regarded as-a~-streptothrix. It is probable that the lungs were the primary point of en- trance of the germs. Ferré and Faguet also found a streptothrix in a cerebral abscess. Fraenkel obtained pure cultures of tubercle bacilli from the pus of a tuber- culous abscess of the brain. These various germs may be derived from any part of the body, but in the large majority of cases the primary lesion is located in the vicinity of the head and is due either to injury of the head or to ear disease. When the disease is due to injury of the head the pyo- genic organisms are sometimes introduced directly from the outer world. For example, in punctured wounds of the skull, the foreign body (splinter of wood, dagger, etc.) may be the direct carrier of the staphylococci and streptococci into the brain. Sometimes the skull itself is infected, then infection thrombi develop in the diploic vessels, and the bacilli pass along the perivascular sheaths to the brain. The infective injury to the skull may also be produced without fracture, if the outer table has been laid bare. In the majority of cases due to injury the abscess is found in the vicinity of the injured part of the skull; but in exceptional instances it is found on the opposite side of the brain (contrecoup). A similar pathological condition is presented by affec- tions of the face and scalp, which may set up thrombosis of the veins and thus communicate with the brain. Next in importance—perhaps even equal—to traumatic causes stand inflammations of the middle ear. The primary lesion is generally present from early childhood, as a sequel of one of the infectious diseases common to that period of life. It terminates in caries of the petrous portion of the temporal bone, attended usually with sup- purative otitis media. Caries in the tympanic cavity usually extends most markedly in certain directions. When it spreads through the antrum and involves the mastoid cells, some of which are adjacent to the sigmoid groove, the latter is apt to be involved and exposed. When the caries attacks the roof of the middle ear, perforation into the middle fossa of the skull frequently results. When the petrous portion is the site of extensive disease, suppurative leptomeningitis of the basal ganglia and cerebellum is apt to occur; even when the destruction is much less marked and the in- ternal auditory meatus is exposed, the infective inflam- mation may pass along the sheaths of the facial and au- ditory nerves. In perforation of the tegmen, the abscess is situated in the temporo-sphenoidal lobe; in perfora- tion into the sigmoid groove, the abscess is generally located in the cerebellum. The mode of development of the abscess may vary considerably. If the tegmen is involved the overlying dura mater be- comes inflamed and adherent to the adjacent pia mater, and thus the veins and lymphatics of the latter are directly affected. The arterial vessels become throm- Brain, Brain, bosed, and particles from the resulting emboli are carried with the pathogenic cocci to the interior of the temporo- sphenoidal lobe where they give rise to an abscess. As in cases of injury, the process may also creep along the perivascular sheaths. When the perforation takes place into the sigmoid groove, the outer wall of the sinus undergoes inflamma- tion; this extends through to the inner wall and thus induces thrombosis. The thrombus offers a nidus for the micrococci which pass along the cerebellar veins to the cerebellum. It must be remembered in this connection that the current of blood in the superficial veins may flow in either direction. The cerebellar arteries may also be thrombosed, and thus convey infected emboli to the interior of the cerebellum. Cerebellar abscess may also be due to direct extension of the inflammation through the dura on either side of the sigmoid sinus. In young children the infection often-travels through the petroso-squamosal suture. Cerebral abscess from ear disease is much rarer after acute suppurative otitis media than after the chronic form. In rare cases it follows tuberculous and syphilitic affections of the temporal bone. Otitic abscesses occur generally in the temporo-sphe- noidal lobe or the cerebellum on the same side as the aural lesion. In 119 cases collected by Koerner, 79 de- veloped in the cerebrum and 40 in the cerebellum. Infection from the nose and its appendages is much rarer. In a case reported by Dreyfuss, the infection, which started from suppuration of the antrum, was due to thrombophlebitis of the pterygopalatine and ophthal- mic plexuses. In another case the process extended to the adjacent ethmoid cells and caused perforation of the lamina cribrosa. When the primary lesion affects the frontal sinuses, the posterior wall usually undergoes per- foration or the iafection takes place through the diploé. In very rare cases the primary infection is located in the orbit. In almost all of this group of cases the abscess is situated in the frontal lobes. Embolic abscesses of the brain may be due to infection in any part of the body. "They are observed particularly in association with pulmonary Tiga putrid bronchitis, empyema, gangrene, tuberculous cavities). They are less frequent after septic endocarditis, suppurative proc- esses in the abdomen, joint and bone suppuration. They have also been seen after typhoid fever, scarlatina, diphtheria, glanders, and general pyzemia. Boettcher re- ports a case after pulmonary suppuration in which lung pigment was found in the brain. In two instances the abscess was due to the presence of oidium albicans. The category of so called idiopathic abscesses of the brain is being continually narrowed. Although the ex- istence of such cases cannot be absolutely denied, still none should be pronounced idiopathic until careful search has been made unsuccessfully in all the organs for some possible source of infection. PaTHOoLoGicAL ANATOMy.—An analysis of 458 cases collected by Le Fort and Lehmann showed that the ab- scess occurred in the cerebrum in 827 cases, in the cere- bellum in 113 cases, in the cerebrum and cerebellum in 11 cases, in the pons Varolii in 5 cases, in the cerebral peduncle in 1 case, and in the fourth ventricle in 1 case. According to Macewen 93 per cent. of traumatic ab- scesses and 87 per cent. of otitic abscesses are solitary. The majority of metastatic abscesses are multiple. Ab- scesses of the brain vary extremely in size. Some of the multiple abscesses occurring in the course of pyeemia or ulcerative endocarditis may be the size of a pea. Old chronic abscesses may occupy a large part of a cerebral hemisphere, or perhaps a considerable portion of the cerebellum. ; Acute abscesses contain a thin pus, usually of a color varying from yellow to green, sometimes of a darker shade, from admixture with blood. Under the micro- scope this is found to contain pus corpuscles, drops of myelin, granular matter, and detritus of the nerve ele- ments and the pathogenic micro-organisms. The walls 219 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. of the abscess are usually irregular and jagged, and tear readily from the contact of the fingers. The cavity is irregular in shape at first, but at a later period it tends to become more rounded. For a varying distance around the cavity the brain substance may have a reddish, speckled appearance from enlargement of the blood- vessels and the presence of capillary hemorrhages. Still more externally the brain tissue is stained slightly yel- low and softened from inflammatory eedema. The latter phenomenon is observed sometimes over a large area, and often appears to be the immediate cause of death. Some- times the abscess ruptures into one of the lateral ven- The membrane rarely insures a complete standstill of the process, inasmuch as it undergoes suppuration in places and this attacks the surrounding brain tissue. The new focus may again be surrounded by a fresh membrane. The contents of the cavity are usually somewhat viscid, and consist of broken-down pus globules, drops of fat, cholesterin crystals, and granular matter. In a very few instances the contents have been found condensed to a thick, cheesy consistence, and in one case it is stated that earthy matter was present (calcification). When the ab- scess is of large size, fluctuation can usually be detected Fic, 808.—Abscess Cavity in the Brain. tricles, and in rare cases the pus makes its way through the foramen of Monro into the opposite ventricle. In such cases death almost always occurs before ependymitis supervenes. Softening may extend to the ventricles and produce ependymitis even though perforation has not occurred. In other cases the abscess ruptures through the cortex (almost always at the convexity), and in this event, likewise, death may supervene before the develop- ment of meningeal inflammation. But in a large num- ber of such cases meningitis occurs at the site of rupture and rapidly spreads over the entire meninges. Quite a number of cases have been reported in which the pus made its way through the original site of injury to the skull, through the external auditory meatus, through the sphenoid bones into the nasal cavity, or through the orbital plate into the orbit. In the majority of cases the amount of healthy tissue between the cortex and abscess does not measure more than a few millimetres in thickness. In rare cases the abscess may be situated an inch or even more from the cortex. The abscess may be connected by a narrow fis- tulous tract with the meninges. Chronic abscesses are usually round or ovoid in shape, and are provided generally with a connective-tissue mem- brane of variable thickness which lines the cavity. Ru- dolph Meyer states that about seven weeks usually elapse before the formation of a well-defined membrane. Lal- lemand found an abscess surrounded by a soft vascular membrane in a case which proved fatal thirteen days after the onset of the first symptoms. Huguenin found no membrane in an abscess which had lasted thirty-two days. Equally varying statements are made by other writers. 220 (Specimen in the collection of Prof. M. Allen Starr, M.D.; photograph taken by Dr. Edward Leaming.) upon the convexity; the convolutions are flattened upon the side of the lesion, and sometimes the falx cerebri is pushed toward the opposite side of the brain. When the abscess is situated in such a position (particu- larly the cerebellum) that the escape of fluid from the ventricles is interfered with, internal hydrocephalus may be the result. The complications of cerebral abscess include suppura- tive meningitis, extradural suppuration, and thrombosis of thesinuses. All these conditions may also precede the development of the cerebral abscess. According to Hessler, among 106 abscesses of the cere- brum 67 were uncomplicated, in 13 there was thrombosis of the sinuses, in 26 meningitis. Among 59 cerebellar abscesses 48 were uncomplicated, thrombosis of the sinuses was present in 10, and meningitis in 6 cases. Macewen has reported a remarkable case of suppura- tive meningitis in the posterior fossa, while simple serous meningitis was found in other parts. Widespread cedema of the brain is found not infre- quently in cases of cerebral abscess, even in those pro- vided with a thick membrane, and which do not appear to have given rise to much pressure. General cerebral anemia is also observed quite often under such cireum- stances. The development of these sequelee is still un- explained. CLINICAL History.—The symptoms of an acute ab- scess of the brain after injury vary to a remarkable ex- tent. Perhaps the immediate symptoms of the traumatism have been very slight; the scalp has been wounded, but the bones have escaped injury, and the patient is not supposed to be seriously injured. Or the patient has presented for a few days the signs of cerebral concussion, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. and then apparently recovers. Fora variable length of time (from a week to two or three months) he continues in apparently good health, but then begins to complain of headache, dulness, and irritability. The headache is one of the most constant and earliest of all the general symptoms. It is rarely absent but varies greatly in in- tensity. It is especially severe during the growth of the abscess, and usually slight during the period of latency. It is sometimes felt over the entire head, but is generally more severe on the side of the abscess. In Koerner’s twenty-one cases of cerebellar abscess, the pain was located in the occipital region only eight times. Pain in the back of the head is sometimes observed in frontal abscesses. Headache is often accompanied by rigidity of the back of the neck, particularly in abscesses of the posterior fossa. In the majority of cases, according to Macewen, the temperature is normal or even subnormal during the en- tire course. When the symptoms begin suddenly fever may be. present, but it is probable that the febrile move- ment is partly due, in many cases, to the primary disease or to complications. As a rule, the pulse is slow at the height of the dis- ease. Toynbee and Wreden described cases in which it fell to 10-16 per minute. The slowness of the pulse may persist during an increase of the bodily tempera- ture. After a while the headache increases in severity, and the patient may be confined to bed on account of the general malaise. The irritability and excitement like- wise increase, delirium supervenes, and epileptiform con- vulsions may make their appearance. Then the delirium changes into hebetude, somnolence, and coma; the pulse becomes rapid and irregular. Death either ensues rapidly or recovery slowly occurs, and the patient is restored apparently to health, with the excep- tion, perhaps, of a monoplegia or hemiplegia, or even without any local symptoms. He then enters upon the so-called latent stage. Thesymptoms described are very like those of acute meningitis, and, indeed, this lesion may be associated with the encephalitis from the begin- ning, or it may develop secondarily. Sometimes the symptoms begin with great suddenness, and at once assume an alarming aspect. In another series of cases the symptoms of concussion ‘or compression of the brain, due to the original injury, continue without intermission or improvement, and are rapidly merged into those due to the developing en- cephalitis and abscess formation, so that it is impossible to tell when the one process ends and the other begins. Such cases usually run a more rapid course than the former variety. Finally, not a few cases have been reported in which the abscess has remained entirely latent for a long period, without giving the least indication of its presence. In fact, the autopsy alone may reveal the existence of a hitherto unsuspected chronic abscess. Ina case observed by Nauwerk, the period of latency lasted twenty-eight ears. Af Sometimes the sole symptom of the so-called latent stage has been the occurrence of epileptiform convulsions, so that the case has been regarded as one of ordinary epilepsy. In other cases, chills, followed by a hot stage and sweating, occur at irregular, or, in rare cases, per- fectly regular intervals, so that a diagnosis of intermit- tent fever has been made. An instance of this kind has come under my own observation. Usually, however, such patients also suffer from violent headache, fre- quently localized in the vicinity of the abscess. Abscesses of the frontal lobe are more apt than others to be unattended with symptoms during the stage of latency. In a case of this kind, observed by me in the person of & lunatic, the mental condition seemed to be somewhat improved during the period of latency (one month). The night before her death, she had what were supposed to be hysterical convulsions (irregular twisting movements without loss of consciousness), as the patient had exhibited other hysterical symptoms for a year (the Brain, Brain, injury which gave rise to the abscess was received a month before the onset of the convulsive seizures), On the following morning the patient was found dead in bed. The autopsy showed an abscess of the frontal lobe, which had burst (evidently shortly before death) through the convexity. The clinical history of otitic abscess of the brain is modified by the symptomatology of the primary disease of the ear. The initial symptoms usually consist of pain in the ear, vomiting, vertigo, tinnitus, and rise of bodily temperature. Inasmuch as all these symptoms may be the result of simple retention of pus in the diseased ear, it may be impossible to determine for some time whether the brain has really become involved. The condition is still further obscured by the fact that in these cases we observe frequent complications with purulent meningitis, pachymeningitis, and thrombosis of the sinuses. In the majority of cases the abscess runs an acute or subacute course, Mental obtuseness generally becomes noticeable soon after the onset of the disease. The patient answers questions correctly but slowly, and, when the eyes are open, stares into vacancy. The somnolence may deepen quite rapidly into coma. When the disease runs a chronic course, the history is essentially the same as that of the traumatic variety. On account of their embolic origin metastatic abscess- es usually develop suddenly. In the majority of cases the emboli enter the middle cerebral artery and are carried to terminal branches, so that we generally find evidences of an affection of the motor region of the brain. Pure Jacksonian epilepsy is not an uncommon feature of these cases. Paralytic symptoms are much more frequent. Various aphasic disturbances have also been observed. In a considerable proportion of cases the abscesses are multiple and the focal symptoms are thus obscured. The brain symptoms are often associated with evi- dences of general infection, viz., fever, chills and sweats, and rapidly developing cachexia. It is unnecessary to say that, if the abscess is situated in such a position that it either involves the cortex in some part which presides over a special function, or destroys the white matter in such a manner as to cut across the fibres leading to such portions of the cortex, the corresponding symptoms will be produced. Thus, hemianopsia, aphasia, word-deafness, paralysis of indi- vidual nerves (very rarely), monoplegia, or hemiplegia may be produced in this manner. As occurs likewise in the clinical history of tumors of the brain, hemiple- gia results usually from a succession of ‘monoplegias, due evidently to a gradual spread of the destructive process from one set of fibres to another. This fact may be of invaluable service in making a regional diag- nosis. But, unlike tumors of the brain, cerebral abscesses rarely give rise to paralysis of cerebral nerves. Choked disc is also much less frequent and less marked than in tumors. According to Oppenheim, choked disc is much less frequent than optic neuritis. The affection of the optic nerve is sometimes confined to one eye. In opera- tive cases the optic disturbances may disappear gradu- ally after the operation. The frequent absence of choked disc may be accounted for, perhaps, by the fact that the encephalitis spreads by causing adjacent parts of the brain to become directly involved in the inflammatory process, and in this way less pressure is produced upon adjacent parts. In a certain proportion of cases all “head symptoms ” are entirely wanting during the so-called latent stage, and we are sometimes astounded at the autopsy at dis- covering the great apparent disproportion between the amount of brain tissue destroyed and the slight character of the symptoms which had been produced. This is es- pecially striking if we compare the symptoms with those which usually result from cerebral hemorrhages, even when much smaller in size. It must be remembered, however, that the latter lesion is usually situated in such a position (internal capsule and surrounding parts) that 221 Brain, Brain, comparatively slight destruction of tissue interferes ma- terially with the conduction of nervous impulses. Vomiting is a not infrequent symptom, and may occur when the stomach is either full or empty. In certain rare cases, the sole symptoms observed dur- ing the period of latency are those of mental derange- ment, and the patient is supposed to suffer from insanity as the result of injury to the head. In a case recently under our observation, such an error in diagnosis was made by a very eminent neurologist, and the true na- ture of the case was revealed only at the autopsy, as the psychical symptoms persisted, uncomplicated with any other manifestations, until the terminal men- ingitis set in. As a general thing, the latent period is brought toa close by a sudden irruption of symptoms, beginning either with an epileptiform convulsion or a series of convulsions, with great exacerbation of the headache, mental irritability and delirium, or with sudden coma. The symptoms which follow are very similar in character to those which we have described above as occurring in acute abscess. After a short period (varying usually from a few hours to several days), the symptoms either terminate fatally (this is the rule) or they gradually clear up. But sooner or later, after another period of latency, in which the symptoms are more violent than in the first period, a second outburst occurs, which terminates fa- tally. From the reports of a few isolated cases it seems prob- able that chronic abscesses may undergo spontaneous re- covery, inasmuch as the pus becomes cheesy or even calcareous. Butsuch an event, if it happens at all, must be extremely rare. DraGnosis.—In making a diagnosis of abscess of the brain great importance attaches to etiological consid- erations. We are rarely justified in making the diag- nosis unless we obtain a history of a previous in- jury to the head, of a purulent disease of the ear, nose, or other adjacent parts, or of some source of in- fectious emboli in distant parts of the body, notably in the lungs. Injury to the head is followed, in rare cases, by tumor of the brain. But in such cases it will usually be found that the primary wound was not infectious in character, and, moreover, the symptoms follow one another in a steadily progressive manner. Furthermore, choked disc is much more constant and pronounced in tumor cerebri, while the subnormal temperature, or the fever and chills of abscess are wanting. Injury to the head may also give rise to other symp- toms which simulate abscess of the brain but which are in reality due to hemorrhagic encephalitis. In the latter affection the symptoms begin suddenly. They may terminate in complete recovery or rapid death, or the majority of the symptoms may disappear and leave per- manent focal symptoms. In considering suppurative disease of the middle ear as a factor in the diagnosis of cerebral abscess, it should not be forgotten that severe cerebral symptoms may be produced by the mere retention of pus in otitis media independently of the existence of cerebral lesions. A number of cases have also been reported in which optic neuritis or choked disc was associated with simple otitis media. This peculiar combination has been explained in various ways, viz., as the result of thrombosis of the sinuses, of infection of the carotid canal and extension along its lymph channels to the sheath of the optic nerve, and of serous meningitis. Extra-dural abscess often cannot be distinguished from cerebral abscess; indeed, in many cases the two lesions are combined. According to Jansen, extra-dural ab- scesses exhibit the following characteristic features: («) thickening of the bone, subperiosteal abscess or cedema- tous swelling behind the mastoid process; (0) pain on pressure and percussion in this region; (¢) impaired mobility of the head, particularly around the sagittal axis; (¢) nystagmus of both eyes, on voluntary motion, chiefly toward the side of the healthy ear. 222 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Otitic thrombosis of the sinuses is also difficult of dif- ferentiation. In the majority of cases there is consider- able intermittent fever, and the pulse is irregular and rapid. Many cases are attended with chills, sweats, and profuse diarrhcea. Insome casesall these symptoms may be wanting. In thrombosis of the cavernous sinus we find cedema of the eyelids and surrounding parts, and protrusion of the eyeball. In thrombosis of the trans- verse sinus, certain symptoms may be due to implication of the upper part of the jugular vein. This vein is tender on pressure and may be felt occasionally as a hard cord. Small abscesses may develop in surrounding parts. (idema behind the mastoid process is very fre- quent. Focal symptoms are usually wanting in thrombosis of the sinuses. When abscess and thrombosis are combined the condi- tion becomes still more difficult of diagnosis. It is also difficult in many cases to differentiate menin- gitis from abscess. The former disease usually runs a more rapid course than abscess, is attended with con- siderable fever and acceleration of the pulse, general convulsions are frequent, and there is also hyperesthesia of the entire skin in many cases. Rigidity of the neck is a common symptom, together with retraction of the ab- domen and increase of the tendon reflexes. In children all these symptoms are sometimes produced by retention of pus in the middle ear and may be relieved by evacua- tion of the pus. The regional diagnosis must be made according to the principles laid down in the articles on Diagnosis of Local Lesions and on Functions of the Cerebral Cortex (both in the present series of brain articles). Proenosis.—The prognosis of this affection has been modified very materially in the last fifteen years by the progress in antiseptic surgery. Spontaneous recovery by caseation or calcification of the abscess or by rupture externally is extremely rare. But operative interference now promises a good measure of success. Oppenheim found that in 53 cases of operation upon traumatic cere- bral abscess 36 terminated in recovery. Koerner col- lated 92 operative cases of otitic cerebral abscesses; 51 cases recovered and death occurred in 41 cases. Mac- ewen’s results were remarkably favorable. Among his 25 cases of cerebral abscess he operated upon 19, and of these 18 recovered. The poorest chances of successful surgical interference are presented by metastatic abscesses in which there is general pyzemic infection. Complication with thrombosis of the sinuses or meningitis also makes the prognosis more unfavorable. TREATMENT.—Medical treatment of this affection, apart from meeting the individual symptoms as they arise, is utterly useless, as we possess no remedy which will cause the absorption of the pus after it has once formed. Prophylactic measures are useful, perhaps, in prevent- ing encephalitis after injuries to the head. The chief measures are absolute mental and bodily rest (the patient kept on his back, not allowed to sit up, to read, or to talk with those around him), which should be continued, if the injury has been violent enough to produce uncon- sciousness, for at least a week or two after the subsidence of the cerebralsymptoms. Inaddition, the bowels should be kept thoroughly open by some mild saline, or by small doses of calomel. Prophylaxis may also prove of benefit in diseases of the ear and nose. Free vent to the pus should always be secured, and paracentesis performed as soon as reten- tion of pus develops. As soon as the diagnosis is assured, operative interfer- ence is indicated. In some cases this has proved success- ful, even when the patient was in a moribund condition or a complication with purulent meningitis had de- veloped. In some instances repeated operations have been necessary, either because the abscess refilled or be- cause fresh abscesses developed in the immediate vicinity of the primary one. Leopold Putzel. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, BRAIN, ANAEMIA OF.—Anzemia is a condition and not a disease in the proper sense of the term. Moreover, it is a condition which rarely or never exists uncompli- cated. The causes which produce it are very apt to pro- duce independently irritation and inflammation, or the same conditions which at first bring about an anzemia of the brain may, if their action be longer continued, excite in its place a cerebral hyperemia. In the present state of our knowledge it is, moreover, often impossible for us to prove whether certain symptoms are really produced by an anzemia or by a hyperemia of the brain, and in such cases we are forced to come to a decision on very imper- fect grounds. Of the fact that the anzemia in itself acts as an irritant on the nerve centres there can be no doubt, but its chief effect on them is produced through the deprivation of nutrition which it causes. In considering anzmia of the brain, it is not possible for us to differentiate the symp- toms caused by deprivation of nutrition to the cerebral tissues through loss of blood and those caused by de- privation of nutrition to the same parts on account of the poverty of the blood in nutritive material suited to their needs. Hence the term cerebral anzemia has come to denote not only that condition in which there is an - absolute diminution of the amount of blood in the brain, but also all those, so long as no toxic element is involved, in which the blood supplied to the brain is, from its com- position, incapable of affording due and sufficient nourish- ment to the tissues. As a change in the condition of the blood is inmost cases concurrent with a diminution in its amount, we may fairly say that cerebral anemia, when universal, is usually “a complex condition, depending not merely upon a deficiency of the quantity of blood supplied to the brain, but also upon a change in its quality, and upon a diminution in the intracranial press- ure ” (Ross, ii., 611). Anzemia of the brain may be either universal or partial, according as the whole or a portion only of the organ is involved. Partial anzmia, except when caused by oc- clusion of a blood-vessel through pressure, thrombosis, or embolism, is rare, and its symptoms are often not recognizable during life. We shall hence consider here only universal cerebral anemia. This may be either acute or chronic, and it may be due to a condition confined to the brain alone or may form part of a general anemia. Acute universal anemia of the brain is always the result of the sudden withdrawal of a large quantity of blood from that organ. It occurs typically in ligature of the large arteries in the neck, the innominate, the carotids, or the vertebrals. These operations are performed usu- ally either on account of injury, or for some tumor or aneurism. The vertebrals were formerly sometimes tied as a cure for epilepsy. 1. The most common cause of acute cerebral anemia is, however, undoubtedly hemorrhage. This may oc- cur from any part of the body, provided only that sufficient blood be lost with sufficient rapidity. Put- ting aside hemorrhages due to injuries, the more com- mon forms are metrorrhagia, especially post partum, epistaxis, heemoptysis, and hemorrhages from the stom- ach and intestines; occasionally also the rupture of aneurisms. In cases of hemorrhage from injury the influence of shock must always be taken into account, as there are few cases of severe injury in which it does not exist toa greater or less degree. The pathological condition exist- ent in shock is as yet unknown. One hypothesis is that maintained by Groningen, that the complex of symptoms known by this name is due to an exhaustion of the medulla oblongata and of the spinal cord, produced by violent and severe drains upon their strength. Other writers consider shock as due to sudden changes in the calibre of the blood-vessels. Thus it is defined by Fischer as a reflex paralysis of the vaso-motor nerves, especially of the splanchnic, produced through a traumatic con- cussion. However this may be, cerebral anzemia is cer- tainly produced by sbock, and, as Travers says of shock and fainting: “They differ in degree and duration more than in kind.” 2. Acute cerebral anemia may be produced by any sudden change in the distribution of the blood im the body at large. Any cause which suddenly attracts a large quantity of blood to one portion of the body will naturally reduce the amount which can go to the other parts, and hence will-induce an anemia in them. This sudden change in the general distribution of blood in the body is said to occur after violent labor, when, the uterine vessels being suddenly released from pressure, large quantities of blood enter them freely and are thus with- drawn from the rest of the body. To this cause are prob- ably in part also due the serious symptoms which some- times occur after the withdrawal of large quantities of fluid from the pleural or peritoneal cavities. Another example of this form of disturbance is given in the action of Junod’s boot, which, if carelessly used, may prcvoke dangerous symptoms. 3. A third cause of this form of anemia is want of energy in the action of the heart. This is a common cause of chronic anemia, but the acute form may readily be produced by any sudden demand for increased exertion on the already weakened heart. This is readily seen in anemic persons and those suffering from insufticient action of the heart, in their liability to faint on any slight exertion, or even on rapid change of position. More especially is this the case in convalescents from acute febrile diseases, and it is particularly apt to occur after acute pneumonia. This frequently takes place when the patient rises suddenly from the horizontal position, the change in the distribution of the blood, which under normal circumstances would not be perceived, making itself felt. In organic diseases of the heart cerebral anzemia in the acute form frequently occurs, more especially in aortic regurgitation, in which death from syncope is not un- common. Persons suffering from myocarditis or from fatty degeneration of the heart are likewise peculiarly liable to attacks of fainting. Anemia of the brain may in like manner be produced by irritation of the vagus nerve through its action on the heart. Brown-Séquard and others have found that crushing of the right semilunar ganglion causes stoppage of the heart, and the deaths which sometimes occur from syncope in nervous and delicate persons, who are suffer- ing from hepatic colic, may perhaps be referred to some similar cause. We may also mention here, though with- out any special reference to the method of their causa- tion, those cases of syncope and collapse which occur in perforation of the stomach or intestines, and in which death is not infrequent. Hill believes that “the cerebral circulation is controlled by the vaso-motor centre acting on the splanchnic area.” That intestinal disturbances even of a light character are especially liable to produce syncope is well known. Even a transient abdominal pain or a slight attack of in- testinal colic frequently causes the symptoms of faintness or even actual syncope. Syncopal cardialgia and a tendency to faint are said to be especially common in those suffering from the dyspepsia of gout. 4. Again, a diminution of the amount of blood in the brain, sufficient to produce the symptoms of cerebral anemia might be caused through the spasmodic contrac- tion of the cerebral arteries. This is supposed to occur, when, from emotion or mental excitement, there is pallor of the countenance, and even loss of consciousness, with- out any failure of the action of the heart. The not un- common occurrence of fainting at the sight of surgical operations, or at the sight of blood, would come under this head. Syncope, and even sudden death, may be caused by the sudden advent of any strong emotion— surprise, terror, grief, or joy. How far ‘shock or the irritation of the vagus comes into play in these cases is yet undecided. Nothnagel considers it possible that in attacks of epi- lepsy we have to deal with a spasmodic contraction of the cerebral blood-vessels, due to the irritation of a cere- 223 Brain. Brain. bral vaso-motor centre; but this cannot in the present state of our knowledge be considered as proved. Hill states that there is no evidence of the causation of cere- bral anzeemia by spasm of the cerebral arterioles. The occurrence of vaso-motor nerves on the vessels of the pia seems probable according to the latest investiga- tions (Obersteiner, Hill). Hill states that “in every experimental condition the cerebral circulation passively follows the changes in the general arterial and venous pressures. ” That cerebral anseemia may also be excited by irritation or stimulation of the sensitive nerves is well known. In- tense pain may produce faintness or even syncope, but the exact method of action by which this effect is brought about must still be considered undecided. Nothnagel’s and Krauspe’s experiments on the sciatic and crural nerves do not appear conclusive, more especially in the face of the conflicting results obtained by Riegel. Ross states that these symptoms “may result from reflex irrita- tion of the vagus or direct irritation of the sympathetic. But the direct effect produced on the nerve centres must also contribute to the result.” Nothnagel considers the cerebral anzemia caused by catheterization to be likewise due to irritation of the vaso-motor centres. 5. Cerebral anzemia may in like manner be produced by the sudden introduction of foreign substances into the cavity of the cranium, thus inducing compression of the blood-vessels. The most common cause of this is an effusion of blood; but in cerebral or meningeal hemor- rhage the pathological condition is a complex one, and it does not properly come within the limits of this article. 6. It is probable that acute universal anszemia of the brain may be induced by certain poisons, but direct proof in this regard is still wanting. Chronic universal anemia of the brain may be produced not only by all the causes mentioned above, provided that their action be gradual and continued for a sufficient length of time, but also by all conditions of the system in which theamount of bloodasa whole is much lessened or its active power much diminished. Hence in all vases of general anzemia and chlorosis we find a corre- sponding anemia of the brain. This is especially apt to occur after long and wasting diseases, such as phthisis pulmonum, Pott’s disease, or long-continued suppuration in anyform. More particularly is this the case whenever large quantities of fluid of any sort are steadily withdrawn from the body for any length of time, as in chronic diar- rhea. Hyperlactation is a not infrequent cause. Noth- nagel, moreover, considers that many of the symptoms occurring in cases of starvation are directly referable to cerebral anzemia, although in these cases there probably always exists a greater or less amount of cerebral irrita- tion. Anemia of the brain and meninges is specially apt to occur in the convalescent stage of acute febrile diseases, “the late cerebral anzemia of severe fevers” of Jaccoud, who considers, however, that this is not a simple anemia but an aneemia with dyscrasia. Affections of the heart, moreover, are not uncommon factors in the etiology of chronic anemia. Whenever there exists a weakness of the cardiac action, whether due to functional causes or to organic lesions, we may suspect anzemia of the brain. This is probably always present to a greater or less extent in cases of fatty de- generation of the cardiac walls and in most cases of un- compensated valvular disease. It is most frequent in insufficiency of the aortic valve. How far chronic anemia may be brought about by the presence of extraneous substances in the cranial cavity is an open question. The presence of inflammatory exu- dations, transudations, or tumors is supposed at times to cause an anemia by pressure, but in many cases an inritative process seems to preponderate and a hypersemia exists. Partial or circumscribed anemia of the brain is caused by the diminution of the calibre of the blood-vessels sup- plying a portion of the brain, or by their occlusion. Unilateral anzemia is produced by ligature of the carotid. 224 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. In many cases it is but temporary, and the symptoms soon disappear, but in others they are said to remain and become more or less permanent. This depends, at least in »art, on the condition of the communicating arteries of the circle of Willis, irregularities in which were found by Ehrmann in from nineteen to twenty per cent. of the bodies taken at random and examined by him. The commonest cause of partial anzemia in the brain is thrombosis, or embolism, by which a blood-vessel is partially or wholly occluded. The presence of tumors or exudations may likewise cause a partial ansemia by pressure exerted over a vascular area, or on a special blood-vessel. How far local spasm of the cerebral blood- vessels may cause circumscribed anzemia is still doubtful. Nothnagel states that it may occur in hemicrania and in the petit mal (epilepsy). Eulenburg says: “The -group of symptoms called hemicrania sympathico-tonica is to be explained by supposing a unilateral tonic spasm of the vessels of the head caused by tetanus in the cervical region of the sympathetic, or in the spinal centre of the cervical sympathetic.” SymMPToMATOLOGY.—Experiments made on compression of the carotids in healthy male adults show that the fol- lowing effects are produced. In the first place, there is pallor of the countenance, then convulsive efforts to close the eyes are seen, with contraction, to be followed later by dilatation of the pupils, a sighing respiration, dizzi- ness, staggering, and finally unconsciousness. A sensa- tion of choking may occur, and sometimes vomiting and general convulsions. How far these symptoms may de- pend on the anzmia pure and simple, and how far they may be due to other causes, we cannot consider here. In the present condition of our knowledge it is not possible to determine with absolute certainty, in regard to many of the symptoms which are present in conjunction with anemia, as to whether they are due to the anemia itself or to various concomitant conditions; while, on the other hand, there are many conditions in which the symptoms generally ascribed to angzemia are present, and in which the condition and circumstances of the general body would point most strongly to an ansemia of the brain, and yet in which, on post-mortem examination, the actual state of the cerebrum would seem to be rather hyperemic than anemic. Thus Flemming, in the “ Pathologie und Therapie der Psychosen,” says: “The fluctuations in the quantitative relations of nutrition in the brain vary be- tween the extremes of lack and of excess of blood, anzemia and hyperemia. Under circumstances which, as well from-the precedent injuries as from the whole behavior of the organism, would lead us to conclude, in so dispro- portionate a blood supply (oligsemia), that even the brain could not readily be provided with its normal needs, we still see the psychical functions altered ina manner which points far more to an increased supply of blood. The autopsy also, in such cases, shows the opposite of what. we should expect from the general oligsemic condition of the body. It shows the brain throughout, or partially, on its surface, or in its internal portions, reddened by the blood seen through the tissues, while the cut surface is dotted with numerous bloody points and the vessels are distended with blood. In short, there where we expected anemia it shows far more a hyperemic condition.” Hence, in describing the symptoms which are usually referred to anzemia of the brain, we desire that these facts be constantly borne in mind, that in many cases symp- toms have been ascribed to anemia which were in all probability due to other conditions of the brain, and even when the anzemia coexists there is in a large proportion of cases no proof that the symptoms are due to it alone. In acute anemia of the brain we have a series of symp- toms extending all the way from general weakness to profound insensibility, and which are known according to their intensity by the names eclysis, lipothymia, and syncope. All these are apt to be classed together under the name of fainting fit. These symptoms are subjec- tively usually as follows: A personabout to faint usually notices first a slight oppression in the breathing, and a sensation of lightness in the head. He is often inclined REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. to gape, and finds difficulty in fixing or concentrating his attention. Gradually the respiration becomes deeper and more labored, and a feeling of nausea and weight in the epigastrium comes on. At the same time his face becomes paler and paler, and he becomes more and more dizzy, until he finds it difficult to maintain his equi- librium. His head feels tense and his ears begin to ring, a mist comes over his eyes, and at times he is scarcely able to see, though still able to stagger toward the fresh air. He is often nauseated, and perhaps vomits. Sur- rounding voices can be heard but not distinguished, and, unless relieved, he becomes insensible and falls without a cry to the ground. If now left to himself he generally soon recovers, but recovery can be readily hastened by the presence of fresh air, or by gentle stimulation of the olfactory nerves. Objectively, the principal symptoms noticeable are, in the first place, the extreme pallor of the face, especially marked on the mucous membrane of the lips, the gaping and deepened respiration, then the staggering or loss of control over the equilibrium. The pupils contract at first and then dilate, and the pulse be- comes small and its tension is diminished. The skin is pale and cold, and a cold perspiration breaks out over the forehead and sometimes over the entire body. This stage ends in the abolition of consciousness and of voluntary movement. These are the usual symptoms in a slight attack of fainting coming on gradually from exposure to heat and close air, or from mental emotion. When the fainting, however, comes on rapidly, the prodromal symptoms may not appear, but the patient turns pale and falls in- sensible almost immediately. In severe cases, in addition to the previous symptoms, we may have Jacksonian epilepsy or generalized convulsions, sometimes extremely violent, and resembling in all respects epileptic convul- sions. These are liable to occur in all cases of sudden and profuse hemorrhage in previously strong and healthy individuals. When the anemic condition is produced more slowly, either from long-continued undernutrition of the body or as the result of a severe physical strain, as a serious fever or other acute illness, the symptoms present themselves in a somewhat different form. In children, after any severe strain on the physical forces, and particularly after intestinal diseases, in which a considerable amount of fluid is rapidly withdrawn from the tissues, we meet with the so-called hydrencephalotd disease, for our knowl- edge of which we are still principally indebted to its first describer, Marshall Hall, who “first gave a cursory sketch of this morbid affection in a little volume of ‘Medical Essays’ published in 1825.” He there says: “The state of exhaustion is very apt to be induced in early infancy, and as the reaction is feeble at this period of life, the case soon assumes the character of sinking. - This state of things is often mistaken for inflammation of the brain or hydrencephalus.” In adults as in children, chronic universal anzemia of the brain is liable to be characterized by a condition of abnormal stimulation, both mental and physical. In both there is the same restlessness, uneasy sleep, and in- tolerance of light and sound; while in adults the mental irritability is probably more prominent only because it is more readily shown. In the severer forms, and more particularly in cases of starvation, delirium, the “ delirium of inanition,” is liable to occur. This is usually active and frequently maniacal in character, and is accompanied by hallucinations, illusions of sight and hearing, and not infrequently by delusions of persecution. Noth- nagel states that there is almost always an undertone of sadness, and that hence the symptoms as a whole belong to the type named melancholia agitans. It is said that occasionally this may pass into permanent insanity. In regard to the delirium of starvation, Longet writes as follows: “There is some consolation for us, after con- sidering the pathological conditions in which hunger presents itself, with the character of inexorable irresistible force, in turning to the analogous phenomena which are produced in the healthy individual when deprived of Viol. 1I—15, Brain, Brain, food. We are compelled to believe that under these cir- cumstances there supervenes a pathological state; a peculiar delirium, that of hunger, the delirium of starva- tion appears; were it not so, we should refuse to admit that the sentiment of egotism could reach the degree to which we see it carried in the starving man. Hunger speaks louder than laws, religion, feelings; all is hushed before its imperious commands.” In the case of Lieutenant Greely, who was exposed to slow starvation in the late Lady Franklin Bay Expedi- tion, the following record was made by Dr. E. H. Green, June 22d, 1884, the day of rescue: “On admission fainted after being carried below in the wardroom, and vomited. Nervous system: excitable and irritable, at times almost emotional, eyes wild and staring; insists on talking, craving news, and demanding food, complains of no pain.” His bodily weight was then one hundred and twenty pounds. In August, 1883, it had been one hun- dred and sixty-eight pounds. The next day: “No sleep, mind more tranquil but too active, great desire to talk and read; less persistent in demanding food; complains of soreness in limbs. June 25th, marked improvement, mind more tranquil; talks quietly without excitement; slept two or three hours naturally, awoke refreshed.” After this there was steady improvement. The details in regard to the other organs of the body are purposely omitted, as not being relevant to our subject, but ‘there was no organic lesion anywhere. All the symptoms here present were probably due to lack of food. We must here again emphasize the fact that in these cases it is impossible in the present state of our knowl- edge to decide how far these symptoms are actually due to a condition of cerebral anemia, or whether, as some observers think, there is present a fluxional hyperemia of the brain. Some of the symptoms present in cerebral anzemia de- serve especial consideration, and among these we should place first the disturbances of the organs of special sense. Tinnitus aurium is one of the commonest symptoms of cerebral anzemia, even in its lighter forms, and is usually accompanied or followed by partial deafness. It is prob- able that these symptoms are due, at least in part, to irritation of the auditory nerve, for although the blunt- ing of the mental perception might readily be adduced as the cause of deafness it could hardly be held to pro- duce a ringing in the ears. Abercrombie’s oft-quoted case of a much-weakened and anszemic patient, who was deaf when he sat upright but could hear well when he lay down, or when his face was reddened, would tend to confirm this view. In the same way the appearance of specks before the eyes and the blurring and dimness of vision which so frequently occur may be referred to irritation of the optic nerve. The occasional occurrence of total amaurosis would also seem to point to this. It is most common after severe hemorrhage, especially from the stomach, rarer in connection with inanition. It may or may not be accompanied by severe pain in the head. It may come on suddenly in the course of a few hours or it may take several days to develop. Travers says: “It succeeds somewhat abruptly to uterine flowing and large and sudden depletion for acute diseases. The pain is not confined to the region of the orbit, though it affects chiefly, if not exclusively, the same side of the head; it is that peculiar nervous pain to which women are subject after uterine hemorrhage, attended with a sense of defined pressure, as of an iron finger on the brain, and sometimes a distressing, jarring noise, like that of a mill or thresh- ing-floor, or the rattling of the shingles as a heavy wave of the sea recedes.” Samelsohn found cause in one case to suspect hemorrhage into the sheath of the optic nerve. A. von Graefe in his cases found nothing on immediate examination, but afterward atrophy of the optic papilla. Schweigger (Transl., Philadelphia, 1878) declares that the relation between loss of blood and disease of the optic nerve is wholly unexplained and that the latter can- not be due to simple anemia. Disorders in the sphere of the motor nerves may be either convulsive or paralytic. Kussmaul and Tenner 225 Brain, Brain. have shown conclusively that in rabbits convulsions are almost uniformly produced in cases of rapid, profuse hemorrhage, or where the great arterial trunks leading to the brain are ligatured, except in the case of very weak animals or in such as were under the influence of ether. They found, however, that closure of all four of the arteries, both carotids and both vertebrals, was neces- sary in order to produce rapid convulsions. In all their cases the convulsions weie epileptic in character. In man convulsions have been noticed in connection with fainting, from the earliest times. Hippocrates says in his Aphorisms: “ Zzacpodu yivovtac % id TAypdo.og 7} Kevootoc”” (convulsions arise either from plethora or from anemia). Marshall Hall, in his observations on blood- letting, declares that “convulsion is, after syncope, the most familiar of the immediate effects of loss of blood. It is most apt to occur in children and in cases of slow and excessive detraction of blood.” . . . And again: “It is most apt to occur in cases in which the patient has been freely bled in a more or less recumbent position, in which the blood has flowed slowly, or in which time has been lost during the operation.” Anzemic convulsions rarely occur except after hemor- rhage, when the amount of blood lost must be consider- able. The loss must occur all at once, or nearly so, and the patient must not have been previously in a much de- bilitated condition. Thus, children in a hydrencephaloid state, and persons suffering from chronic anemia, are not likely to be attacked with anemic convulsions. In contradistinction to convulsions complete paralysis without coma does not occur in universal cerebral anzemia, though after ligature of a carotid temporary hemiparesis and paralysis are not uncommon. If the paralysis be permanent there is probably some organic lesion pres- ent. The general weakness of the limbs in syncope may be regarded asa form of paresis. “Cheyne-Stokes respira- tion and Traube-Hering blood-pressure curves are very common in states of partial anzemia of the bulbar centres ” (Hill). The Dracnosts of anemia of the brain, except in those cases of partial aneemia due to the obliteration of blood- vessels, which do not come under consideration here, can be made only through consideration of the accompanying general symptoms. Inasmuch as in hyperemia of the brain the local symptoms are in many cases the same as in anemia, the differentiation of these two opposite con- ditions will depend much on the history of the case. Even the condition of the vessels of the face and head is no positive proof of the condition of the internal vessels, nor would an increase or diminution in the supply of blood in the retina afford more than a presumption that the same condition existed in the meninges. The condi- tion of the heart and the influence of vosture and of al- coholic stimulants afford further aid in determining the diagnosis. The PRoGNosis in common cases of syncope is decided- ly favorable, although even in ordinary cases of fainting from mental infliiences fatal results now. and then occur. Less favorable is it in cases due to severe hemorrhage, even when not complicated by shock. On the other hand, in those cases of acute syncope where we have reason to suspect some weakness or lesion of the heart, —for example, in all cases of cardiac disease, and in con- valescence after acute febrile diseases,—the prognosis is more serious. This especially applies to those cases in which the immediate cause of the syncope is some sud- den change of position. In cases of chronic anemia in the adult, syncope, as a rule, is not in itself a very seri- ous symptom, but whenever a prolonged coma occurs, especially if accompanied by convulsions, there is cause for anxiety. In the hydrencephaloid condition in chil- dren, if the patient be seen and the disease recognized in time, recovery is probable under judicious treatment. The prognosis must in all cases depend, in this as in other diseases, in great part upon the severity of the symptoms. - The condition of the pupils is said to form an important element in the prognosis, contraction al- 226 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ways preceding dilatation, while they become normal again as the patient approaches recovery. TREATMENT.—In simple syncope from mental emotion or from reflex irritation but little treatment is needed, except that the patient should be placed in a horizontal position and should be allowed plenty of fresh air, when recovery generally occurs quickly. Stimulants, such as. ammonia, applied to the mucous membrane of the nose and air passages, are of assistance. As the syncope be- comes more severe, we employ cutaneous stimulants, the simplest and best of which is the sprinkling of cold water over the face and chest. Mustard may be applied to the skin, especially over the cardiac region; but the most. effective external stimulant is the electric brush. Internal cardiac stimulants, such as coffee, alcohol, or ether, are: often of decided benefit. The carbonic dioxide in cham- pagne is said to promote the rapid absorption of the al- cohol, and hence this form should, when convenient, be: used. In the severer cases, when the unconsciousness. becomes prolonged, especially in those in which the loss. of blood has been very great, the limbs should be ban- daged, so as to drive all the blood as far as possible into. the body and head. As a last resort, transfusion should be attempted. In cases of chronic anemia all means should be used to improve the general condition and strengthen the bodily forces. Milk is often the best form of nutriment, but when it can be borne a generous diet, including eggs. and meat, is advisable. Wine is frequently of benefit when given in suitable doses, and in severe cases it is- often indispensable. Alcohol is generally of much im- portance in cases of hydrencephaloid, and in these Noth- nagel recommends the early use of musk. In all cases- the surface of the body should be kept warm, if neces- sary, by the direct application of heat. When mental excitement exists, all cutaneous stimu- lants or irritants are to be avoided, as they are said to- increase the pain and restlessness. Under these condi- tions opiates often act well, better probably than chloral, which has also been recommended by good authorities. William N. Bullard. BIBLIOGRAPHY. Hall, Marshall: Medical Essays, London, 1825, Gooch: Account of Some Diseases Peculiar to Women, 1829. Abercrombie: Pathological and Practical Researches on Diseases of the Brain and Spinal Cord, Edinburgh, 1829. Hall, Marshall: Researches, Principally Relative to the Morbid Effects: of the Loss of Blood, London, 1830. Observations on Blood-Letting, London, 1836. Lectures on the Nervous System and Its Diseases, London and Philadelphia, 1836. Cooper, Sir Astley: Guy’s Hospital Reports, vol. i., 1836. Kussmaul and Tenner: On the Nature and Origin of Epileptiform Convulsions Caused by Profuse Bleeding, etc. Translated bv Bron-- ner, New Sydenham Society, 1869. (Original in Moleschott’s Unter-- suchungen, iii., Frankfort, 1857.) Nothnagel: Virech. Arch., Bd. xl., 1867. Jolly and Riegel: Virch. Arch., Bd. lii., 1871. Krauspe: Virch. Arch., Bd. lix. Fischer: Ueber den Shok. Volkmann’s Vortrage, No. 10. Nothnagel: Article, ‘* Anzemia, Hyperzemia, Thrombosis, and Embo-- lism of the Brain,’ in Ziemssen’s Cyclopeedia, vol xii., 1877. Jaccoud: Traité de pathologie interne, Paris, 1879. Ross: Diseases of the Nervous System, vol. ii., New York, 1888. Boston Medical and Surgical Journal, exi., No. 8, 1884. Green: Boston Medical and Surgical Journal, exi., No. 10, 1884. Hill: The Physiology and Pathology of the Cerebral Circulation,. London, 1896. . Obersteiner: Jahrb. f. Psychiatrie u. Neurol., xvi., 215, 1897. BRAIN AND NERVES, CHEMISTRY OF.—The pro- portion of water in the nervous tissues varies at different. ages and in different parts. It is more abundant in the gray than in the white matter and in early than in adult: life. In the gray matter of the adult it forms about eighty-five per cent. of the total constituents, in the: nerves about sixty-five per cent. The solids comprise the following: 1. Proteids, including nucleo-proteids, globulins, and, according to some, albumins. 2. Substances rich in combined phosphoric acid: nu- clein, protagon, lecithin. 3. Complex nitrogenous substances, yielding a carbo- hydrate on decomposition and known as cerebrosides. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. 4. Cholesterin, a complex alcohol (C.;H,,OH). 5. Neurokeratin, a substance resembling ordinary ker- atin (from hair, etc.) and found in neuroglia and the medullary sheaths. 6. Extractives: Kreatin, xanthin, hypoxanthin, inosit, lactic acid, uric acid. 7. Inorganic salts. Several of the above call for a brief note. Nuclein is a compound formed by the union of a pro- teid with nucleic acid. Nucleic acid is phosphoric acid, P.O;, combined with a member of the purin group (xan- thin, hypoxanthin, adenin, guanin). Protagon, discovered in 1865 by Liebreich, was stated by Hoppe-Seyler and others not to be a definite substance but a mere mixture. Recently, however, its existence has been confirmed by numerous workers. Gamgee and Blankenhorn suggest CisoHsosNsPOs5, as its empirical formula, but others claim that it may be found in several closely related varieties. On decomposition it yields one of the cerebrosides and the decomposition products of lecithin (fatty acids, glycero-phosphoric acid, and cholin). It may be obtained as a loose, white powder. It dissolves in eighty-five per cent. alcohol at 45° C., but separates on cooling as a snow-white, flaky precipitate consisting of balls or groups of fine crystalline needles. The Cerebrosides are complex nitrogenous substances, yielding among their products of decomposition fatty acids and a carbohydrate (galactose). A number of varieties have been described, among which the best recognized are cerebrin, homocerebrin, and encephalin. Kossel and Freytag give the formula of cerebrin as C3 oHi40.N2013, and of kerasin or homocerebrin as C7oHise- On2. The relative proportions of the above-mentioned sub stances vary in different parts of the nervous system, but the following figures are probably approximately correct. The total solids vary from 10 to 40 per cent. and are made up as follows: Of the total solids: Proteids, 25 to 55 per cent. ; nuclein, 1 per cent.; protagon, 5 to 10 per cent. ; lecithin, 10 to 80 per cent. ; cerebrosides, 0.5 to 10 per cent. ; cholesterin, 10 to 50 per cent. ; neurokeratin, 3 to 6 per cent.; salts, 0.5 to 2 per cent. The proteids are most abundant in the gray matter, cholesterin and the cerebrosides in the white matter. The salts are given as follows by Geoghegan in parts per 1,000 of brain: POLAT ASD so 1s;0.0 e106 2 Potassium ....... 0 Sho15 0010 00 Ree OO A 7 Magnesium 2 Calcium ......... 09 The reaction of the central nervous system, especially the gray matter, has been stated by many writers to be acid during life, but according to Halliburton it does not become so till shortly after death. T. Wesley Milts. William 8S. Morrow. BRAIN, ANEURISM OF ARTERIES OF.—Aneurisms of the cerebral vessels (independently of the miliary aneu- risms which are treated of in the discussion of Cerebral Hemorrhage) are comparatively rare, though Coats makes the surprising statement that, “in persons under forty years of age cerebral hemorrhage is due to the rupture of aneurisms in the great majority of cases.” These aneurisms are situated commonly on the arteries of the circle of Willis, and, according to Lebert, the ves- sels are affected in the following order of frequency: basilar, middle cerebral, internal carotid, and posterior communicating, and the artery of the corpus callosum. The middle cerebral and basilar are involved in more than half the cases. The other vessels are only excep- tionally the site of this lesion. Robertson reports a case in which an aneurism had burst into the right lateral ventricle. It wassituated on a branch of the right middle cerebral artery, and had hollowed out a bed for itself in the substance of the corpus striatum and optic thalamus. | of the vessel. Brain, Brain, According to the majority of writers, the vessels of the left side appear to be affected more frequently than those of the right side, but in Coats’ eleven cases all were situ- ated on the vessels of the right side of the brain. The male sex seems to furnish a mueh larger proportion of the cases than the female sex. The anatomical structure of cerebral aneurisms is en- tirely similar to that of similar lesions in other vessels of the body, and therefore need not be discussed here. They vary from the size of a pea to that of a hen’s egg, though tumors of the latter dimensions are extremely rare. As a rule, they do not exceed the size of a hazelnut. The immediate causes of the origin of this lesion have not been ascertained very clearly, but there appears to be little doubt that it does not bear such close relations to atheromatous degeneration as aneurismal dilatation of other vessels of the body. Ina considerable proportion of cases the aneurism is the result of embolism, and this explains its comparative frequency at an early age (endo- carditis, heart disease). Imperfect closure of the vessel by the embolus leads to inflammatory changes in the walls of the vessel, and, as the lumen is still partly open for the passage of blood, the weakened walls yield to the blood pressure and an aneurism is gradually produced. Syphilis acts in a similar manner by weakening the walls of the vessels. The lesion has also been attributed to the effects of in jury to the head. The aneurism produces various local effects. When situated in the circle of Willis it may cause erosion of the bones at the base of the skull. Asa matter of course, it also produces pressure on adjacent soft parts, and as the circle of Willis is usually involved, the various cerebral nerves are mainly subject to compression, then the me- dulla oblongata, pous Varolii, and crura cerebri. Klippel reports a case in which an aneurism of the right posterior communicating artery, as large as a wainut, had com- pressed the adjacent brain substance from the edge of the pons to the right optic nerve. During life the pa- tient had suffered from ptosis of the right side and com- | plete immobility of the right eye, with disturbance of vision on both sides. The aneurismal sac may also press upon adjacent ves- sels and give rise to thrombosis, with its usual train of sequences. In other words, the pressure effects are very similar to those of other forms of tumor situated at the base of the brain. An aneurismal murmur has been heard in a few cases, on auscultation of the skull. In still rarer cases this murmur has been heard by the pa- tient himself. When the aneurism is situated upon the basilar artery it is apt to giverise to hemiplegia. According to Lebert, this occurred nine times in thirty-one cases. Schmidt re- ports a case in which a diagnosis of cerebral hemorrhage had been made: A man, aged fifty-seven, had an apoplectic attack with unconsciousness, left hemiplegia, including the facial nerve; the pupils were sensitive to light; sensibility was: intact. The condition of the lower limb improved con- siderably, the arm became contractured. Death occurred: two years later from pneumonia. The autopsy disclosed a cylindrical aneurism of the basilar artery, extending from the lower end of the pyra- mids on the left to the corpora candicantia on the right. There was a depression of the pyramids in the medulla oblongata, and its edges were softened; also a depression in the pons, chiefly on the right side. There was distinct gray degeneration of the left lateral column of the cord and median bundles of the right anterior column. Although, as I have stated above, the symptoms of cerebral aneurism are usually very similar to these of other kinds of tumors situated at the base of the brain, it differs from them in the fact that choked disc is a very rare symptom in the history of the former affection. In this respect it is somewhat similar to cerebral abscess, and, like the latter, it may also remain latent until the occur- rence of a sudden apoplectiform attack, due to the rupture In quite a number of instances it has been 227 Brain. Brain, found that the first rupture of the vessel did not prove fatal, and that a second rupture occurred after a variable period, sometimes extending over a couple of years. The majority of writers assert that the rupture of the aneurism gives rise to meningeal hemorrhage; but this opinion should be revised in view of the fact that in all (eleven) of Coats’ cases, and in a number reported by other observers, the hemorrhage took place into the sub- stance of the brain. The extravasation is generally so extensive that it breaks through the brain tissue into the lateral ventricles, and often also into the other ventricles. Treatment of this affection is altogether futile. The most that can be done is to relieve the pain (which is often even more excruciating than that caused by other forms of cerebral tumor) by the administration of mor- phine. Trial may be made of potassium iodide, as, in aneurism in other parts of the body. Leopold Putzel. BRAIN, ATROPHY OF.—As applied to the brain, the term atrophy embraces the results of three different kinds of morbid processes. In the first two there is really atrophy in the ordinary meaning of the term—that is, loss of substance through previously existing disease. Thus: First, loss of substance, either from idiopathic disease inherent in the brain, progressive general paraly- sis; or associated with general disease, infectious fe- vers; or, from failure of nutrition, senescence, insanity. Second, loss of substance from destruction of tissue, or from a sclerosis secondary to localized destructive lesions. In the third class there is no proof that a tissue once ex- isting has been destroyed, and the term atrophy can be used only by a certain license. But for practical conveni- ence there are many reasons for ranking the cases in question with the atrophies. They are, third, cases of imperfect development of the brain, cerebral agenesia, partial or general (microcephalus). This classification of cerebral atrophies is traversed by another division into congenital and acquired; since many cases of arrested development of the brain are clearly traceable to diseases identical with those which occur after birth. The agenesia is then secondary, and except from its intra-uterine origin, could be referred to the second class of cases. CONGENITAL, PRIMARY, AND GENERAL ATROPHY OF THE BRAIN constitutes microcephalus, the rarest form of idiocy (Ireland). No destructive lesion is discernible, but the size of the brain as a whole is much below normal, and the internal proportion of its parts isdisturbed. The dimensions of the cranium correspond to those of the brain, and thus during life the size of the latter can be estimated by measurements of the former. Normal mental faculties are impossible with an adult head of from eleven to thirteen inches in circumference and from eight to nine inches from the root of the nose to the pos- terior border of the occipital bone. A circumference of fourteen to seventeen inches and an antero-posterior diameter of eleven to twelve decimetres implies a brain too small for ordinary intelligence (Voisin). Ireland calls microcephalic all adult heads below seventeen inches in circumference. The lightest human brain on record weighed six ounces, in a child five months old (Sanders). In this the circumfer- ence of the head was less than six inches. Several brains are described of seven ounces (normal weight for men, forty to fifty-two and one-half ounces; for women, thirty- five to forty-five ounces. In microcephalic brains, the frontal lobes taper to a point; the occipital lobes either taper, or are much shortened, in either case exposing more or less of the cerebellum. The parietal and temporo- sphenoidal lobes are the best developed. The corpus callosum is often thinned, or shortened at its posterior end. The island of Reil may be left uncovered. The convolutions are remarkably simple; few secondary folds are developed. The disposition of many sulci is changed, the fissure of Sylvius shaped like a V, instead of a Y (Vogt); the calcarine fissure is prolonged so as to sepa- rate the gyrus fornicatus from the gyrus hippocampi 228 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. dl (Putnam-Jacobi), the bridging convolutions of the occip- ital lobe are indistinct or wanting (Betz). Ina celebrated hypothesis, microcephalic brains have been considered to constitute anatomic reversion to the ape type (Vogt). There is, however, no constant resemblance between the two; the brain of the microcephale may be simpler than that of orang or chimpanzee, it is not similar (Gratiolet, Adriani). , The intelligence of microcephalic individuals who sur- vive is rudimentary, but at various degrees removed from imbecility, complete aphasic idiocy. There is no definite proportion between the degree of intelligence and the size of the brain. Inthose whoattain adult age a certain amount of speech is often possible, and there is some power of attention, memory, and emotionality. Some- times the amount of intelligence is remarkable, if we consider the dimensions of the cranium (case, Antonia Grandoni; circumference of head, at age of forty-one, thirteen inches). There is usually full and restless use of the limbs, and the impressions of the senses are lively. The absence of local or general paresis distinguishes cases of pure microcephalus from those in which the arrest of cerebral development is associated with destructive lesions. Sometimes, however, the muscles are notably feeble, the characteristic restlessness of microcephaly is exchanged for immobility, varied by rhythmic, swaying motions (Meynert). In these cases there is probably nutritive alteration of the brain tissue; or deficient elaboration of its minute structure (Jastrowitz). There may be persistence of the molecular substance which precedes the formation of the medullary sheaths to the nerve fibres, or of the large granular fat cells, which be- long to the transitional stage, and have been sometimes taken as evidence of congenital inflammation (Virchow). CONGENITAL PRIMARY (?) AND PARTIAL ATROPHY.— In this class of cases, one or more portions of the enceph- alic masses are absent, and no traces remain of destruc- tive lesions sufficient to account for their disappearance. Thus they have been explained by a primary aberration of development. The explanation is most plausible in regard to partial or total defect of the corpus callosum (Hitzig). This great commissure begins to develop toward the end of the fourth month,of pregnancy, by buds which appear on the internal lateral surfaces of the hemispheres, and grow simultaneously inward and back- ward. In partial defect it is the posterior portion of the corpus which is wanting, showing an arrest of the partly completed process. The arrest sometimes involves the fornix trigonum and septum lucidum, sometimes these are intact. In all recorded cases, the anterior white com- missure is preserved. The lateral ventricles are dis- tended. This fact suggests that an undeveloped corpus has been destroyed by a ventricular effusion, the latter subsequently reabsorbed. The cerebellum has several times been found defective. In one celebrated case, unique according to Hitzig, the organ was completely wanting, being reduced to two small knobs, at the base of a serous cyst which occupied its place under the ten- torium (Cruveilhier and Combetta, case Labrosse). Hitzig explains this case by an arrest of development; the author, much more plausibly, by a serous apoplexy which had occurred in early or in fetal life. The loss of the cerebellum was accompanied by total absence of the pons; the pyramids arising directly from the cerebral peduncles. In Otto’s case, the cerebellum was very much reduced in size by filling up of the occipital fossz, through inflammatory thickening of the bones. The atrophy was therefore again a secondary lesion. Atrophy of the cerebral hemispheres is usually evidently traceable to destructive lesions. Sometimes, however, the traces of these have disappeared, and the atrophy then seems primitive. Cruveilhier describes the reduction of one hemisphere to one-third the size of the other. The space beneath the dura mater was filled with serous fluid. Iso- lated groups of convolutions are often atrophied: thus, lower part of the central convolution, with supramar- ginal and superior temporo-sphenoidal (Beach); central convolutions on one side (Virchow’s Archiv, July, 1882); REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, central convolutions on both hemispheres (McNutt); right ascending parietal convolution (Bastian); right cerebrum, right crus, pons, and pyramid, left lateral pyramidal tracts (Pick); paracentral lobule, superior ex- tremity of left ascending parietal convolution (Varigny). In many of these cases a primitive arrest of development has been assumed; in none is it demonstrated, or even probable (Steffen, Brouardel, Hasse). The entire class of cases should therefore be consolidated with secondary atrophies. CONGENITAL SECONDARY ATROPHY.—This is partial or general, according either to the extent of the destructive lesion, or of the interference with the general develop- ment of the brain which may have been exerted by a localized lesion. Nutritive processes throughout the brain may be so disturbed that nerve tissues cease to grow, nutrition is diverted to the cranial bones, prema- ture ossification of the skull occurs, with some degree of microcephalus. On the other hand, with a fetal hydrocephalus, all the brain above the medulla may be destroyed and con- verted into a serous cyst, while the cranial bones con- tinue to grow, until after birth the head attains a cir- cumference of two feet (Cruveilhier). The lesions leading to congenital cerebral atrophy are produced during fetal life, and do not differ essentially from those which may be occasioned during the process of parturition, or so soon after birth that the symptoma- tology becomes identical with that of strictly congenital lesions. They are, in addition to the hydrocephalic effu- sions just mentioned, hemorrhage, inflammation, and soft- ening by steatosis. Throughout fetal life the rapidly growing brain is exposed to a graded series of accidents, corresponding to varying tendencies to effusions from the cerebral blood- vessels—now serous, now sanguinolent. At a certain degree of intensity these dropsies or hemorrhages result in complete malformation of the brain (hydrencephalon, or anencephalon); more limited in extent, the effusion results in the formation of a cyst, whose contents may be clear serum, or serum stained with the coloring matter of blood. The cyst replaces whatever nerve tissue has been destroyed. Intra-uterine cerebral hemorrhage is much more liable to occur into the meninges than into the substance of the brain itself. A clot is then formed in the cavity of the arachnoid, and lying upon one or both cerebral hemispheres, which it is destined to com- press during the process of its shrinkage. The subjacent tissues atrophy under the double influence of the pressure and of the sclerosis excited by its irritation. Precisely such arachnoid hemorrhage, with consecu- tive atrophy, is a not uncommon accident of a difficult parturition; and is thus the efficient cause of many cases of idiocy and spastic contracture. Hemorrhage is also possible, but much less frequent, during the first months or year after birth. The cerebral atrophy, however, can be called congenital only when dating from accidents which occur previous to all distinct psychic develop- ments, thus hardly after the first month. Meningo-encephalitis is, during the period immediately succeeding birth, more frequent than hemorrhage, and also occurs before birth. An intense form, occurring at the third or fourth month of pregnancy, is probably the cause of the pseudencephalic monstrosity. Traces of a more tolerable, and even extensive, grade of inflamma- » tion are found in thickened brain membranes, enclosing shrunken masses of nerve tissue, or even empty of these. All but the most limited and localized cases of menin- gitis are liable to be complicated by hemorrhage from the tender blood-vessels. Localized basal meningitis may interfere with the development of the brain, and thus, if the paradox be permitted, cause a species of primary atrophy, with premature ossification of the skull. The most striking effect of such lesion, from its proximity to the optic chiasma, is a descending neuritis and atrophy of the optic nerves. When a portion of the brain has been destroyed by either hemorrhage or inflammation, serum is poured out to fill the threatened vacuum. This non-encysted fluid is found both in the ventricles, in the cavity of the arachnoid, and in the subarachnoid space. It constitutes the so-called hydrocephalus e vacuo, which must always be interpreted asa secondary lesion, and not as the essen- tial cause of the symptoms observed during life. In certain cases a portion of the nerve tissue of the brain is found to have simply disappeared, sometimes throughout the entire depth of the hemisphere, thus leaving an opening which leads from the convexity pia to one of the ventricles (porencephalic defect, Kundrat), This lesion is not entirely peculiar to the new-born, for it has been found in adults after chronic brain disease (Cotard). In the new-born, however, it is due to a pecul- jar lesion, a steatosis of the nerve substance, which re- sults in red or white softening, according as it is or is not complicated by vascular congestion and capillary hemorrhage (Parrot). The foci of steatosis contain a great number of granular corpuscles, due to the fatty infiltration of neuroglia cells; also free granulations and species of cylinders, resulting from deformation of the corpuscles of Gluge. The veins are occluded by thrombi. The nerve tissue is reduced to a milky pulp, and, if the process lasts long enough, is gradually reabsorbed. The lesion may be circumscribed to a mass the size of a filbert, or may extend nearly throughout a hemisphere. In the first case it is usually multiple; in the second, the corpus callosum is the most affected. One of the most important anatomical consequences of any of the above-described lesions of the brain is a de- generation of the motor tracts which lead from the seat of the lesion to the lateral and innermost fasciculus of the anterior columns of the spinal cord (crossed and pyram- idal tract). This degeneration involves two elements: atrophy of the myeline sheaths of the nerve tubes, and proliferation of the neuroglia tissue between them. These elements are combined in various proportions, and when the atrophic process predominates, it is difficult to say that a simple agenesia of the spinal cord has not com- plicated an arrest of development of the brain. The fibres of the pyramidal tracts assume their myeline sheaths much later than the other segments of the cord, beginning at the fifth month; but they should be com- pleted at birth in the cord (Flechsig), though still incom- plete in the cerebral peduncles (Parrot). Simple defect of these sheaths, therefore, without sclerosis, might, at birth or a little before it, result from a check to the de- velopmental process, dating from some epoch of the sixth, seventh, or eighth month of intra-uterine life. ... Dural. Meningea anterior...... Preduralis........ Predural. : Meningea media....... Mediduralis...... Medidural. Meningea parva ....... Parviduralis ..... Parvidural. Meningea posterior .... Postduralis ...... Postdural. Meningea inferior ..... Subduralis....... Subdural. Sinuses. Oy a superior Longitudinalis ... Longitudinal. az Longitudinalis inferior Falcialis ......... Falcial. az.). Torcular Hero- Pp Goatoens sin. KOZ.) TOTCHIAD .. si.5.00 0% Torcular. um Sphenoparietalis Saae : fi ‘Ale parvee .... Sphenoidalis ....: Sphenoidal. Petrosus superior...... Superpetrosus.... Superpetrous. Petrosus inferior....... Subpetrosus...... Subpetrous. Petrosus anterior ...... Prepetrosus...... Prepetrous. [RQGUMISUROI CS) sietvecsccnsic LONLOTH 4 osccceee Tentorial. Lacunz laterales sinu- Lacune parasinu- Parasinual * spaces. um. ales. Intrinsic Veins of the Brain. Cerebri superior........ Supercerebralis .. Supercerebral. Cerebri anterior eats anterior ex-} Precerebralis .... Precerebral. ma Cerebri media.......... Medicerebralis ... Medicerebral. Fossz Sylvii ........... PVA Vidicreteteleveytiars v:tie Sylvian. Basilaris Rosenthali Cerebri inferior s. as- + Subcerebralis .... Subcerebral. cendens Occipitalis lateralis Cerebralis lateralis et inferioris Occipitalis interna Cerebri posterior in- ferior Callosi terna. Magna Galeni Cerebri interna communis Cerebri interna s. inti- ma s. profunda Right and left vein of Galen Postcerebralis.... Postcerebral. Suboccipitalis .... Suboccipital. posterior ex- Callosalis ........ Callosal. (ag). Galentnasesses oc Galen’s. * The form parasinual was kindly suggested and approved by Prof. B. I. Wheeler, the comparative philologist. Corporis striati l ae A Lateralis ventriculi f T#Dialis......... Tenial. peer ae eGo Precornualis ..... Precornual. Septi lucidi aD Ae ; Antr.-ventriculi t Paraseptalis...... Paraseptal. Cornu posterioris Postcornualis .... Postcornual. Ohoroldeawee cnewshuces. Medicornualis .... Medicornual. Medullares superiores.. Superalbales ..... Superalbals. Rami corporis striati... Striatales ........ Striatal. Rami thalami optici.... Thalamici........ Thalamic. Ramus thalami optici ap et (Rosen- | phalamocruralis . Thalamocrural. Pedunculi cerebri Azygos conarii ........ Conarialis........ Conarial. Cerebelli sup. media.... Supercerebellaris. Supercerebellar. Cerebelli sup. lateralis.. Paracerebellaris . Paracerebellar. Cerebelli inferior ...... Subcerebellaris... Subcerebellar. Dural Veins. Durze matris cerebri | : Meningea fo LACIE Seo Dural Meningea media ....... Mediduralis ...... Medidural. Ophthalmomeningea.... Ophthalmoduralis Ophthalmodural. ARTERIES. The encranial arteries present two distinct systems of vessels: I. The dural, commonly called meningeal. II. The intrinsic, or those of the brain proper. These latter do not anastomose with any other arteries. Rarely there are marked exceptions to this rule, and per- haps oftener slight inosculations about the sella turcica. Heubner (1874), from injections in adults, says: “The territories of the medidural and of the cerebral arteries must be considered as absolutely independent of one an- other.” Langer (1877), speaking of infantile and young subjects, states: (a) that one or two dural branches of the precerebral anastomose in the falx with terminal twigs of the dural artery; (0) also that pial branches of the pre- cerebral may reach minute dural arteries accompanying the supercerebral veins as they spring over to the dura near the longitudinal sinus. I. THe DuRAL VESSELS ramify in the exterior of the dura. Ina general way it is true that the pre-medi- and post-dural arteries are branches respectively of the in- ternal and external carotid and vertebral arteries. These various branches interanastomose freely, so that dural infarction does not occur. They are distributed not simply to the dura, but also to the diploic cranial bones; small twigs may also pass to extracranial parts. 1. The Branches from the External Carotid supply the middle belt, and, in fact, nearly the whole of the dura. They are: (1) The Medidural, the largest and most constant ofall the dural arteries, arising from the internal maxillary and entering through the spinous foramen. Its branches pass up the divergent sulci meningei (for arteries and accompanying veins) of the lateral cranial wall, connect- ing at the top with those from the opposite side. Of its two main divisions, the larger anterior is often for a short distance arched over to a canal. The furrows of the medidural artery on the entocranial wall deepen with years, and in old age the artery sinks quite into them. It has two primary branches, a larger cephalic and a caudal, the former again soon (at the sphenoidal angle of the parietal bone) separating into two secondary rami. The anterior ramus runs up behind the coronal suture, though a little more obliquely, being, according to Marchant, pretty constantly from 0 to 18 mm. (averaging 5 to 6 mm.) away at the foot of the suture, about 1 cm. at its middle, and 15 mm. at its dorsal part. The second ramus starts on the entotemporal sur- face 4 cm. behind the pterion, on an average. At its middle, on the entoparietal surface, it averages 54 mm. behind the coronal suture. Farther dorsad, the distance is very variable, 830 mm. more or less. ; The primitive caudal branch leaves the temporal squama 58 mm. behind the pterion, then goes toward, and becomes parallel with, the lambdoidal suture. The relations of these vessels to the subjacent cortex, important clinically, Duchaine sums up thus: (1) The cephalic branch runs up opposite the frontal lobe some 249 Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. centimetres before the central fissure, rather nearer the coronalsuture. (2) The midramus starts almost opposite the fissure, then runs up some centimetres behind it. (8) ‘The caudal branch is always a centimetre or more distant from the fissure, and is still farther separated above. Besides many minute branches to the sinus walls, out- going nerves, and orbit (vide infra), it may send to, or re- ceive from, the deep temporal region minute rami per- forating the interposed wall; in young subjects (Hyrti) considerable branches may pass through the anterior fontanelle and the sagittal suture to the soft cranial cov- erings. Oy The Parvidural, an inconstant accessory medidural, arising close to the latter, or even directly from it, and entering by the oval foramen. It goes to the Gasserian ganglion and adjacent dura. (8) The Mastoid branch of the occipital (or external carotid, 15 in 120 times, Wyeth, 1878), entering by the mastoid foramen, within which it always sends a branch to the diploé. It is small, variable, and destined for the wall of the lateral sinus and adjacent dura. Here again ‘a reverse course has been observed, where the postauricu- lar arose froma duralartery by emerging through a fora- men in the mastoid (Bankart). (4) Supradural branch or Ramus Parietalis, also from the occipital, accompanying the emissary through the parietal foramen. It is usually insignificant, and often absent. (5) The Subdural branches are very small and variable. They include twigs from the ascending pharyngeal, oc- cipital, and stylomastoid arteries, enter by the pre- and post-lacerated, precondyloid, and stylomastoid foramina, and partly supply the dura of the posterior fossa and basilar sinuses. 2. Branches from the Internal Carotid.—(1) The cavern- ous carotid yields several small rami to the sinus wall, the pituitary body, Gasserian ganglion, and dura about the sella turcica. These are variously styled receptacular and vayed arteries, even predural in case of any prominent single branch. Their field of distribution and that of the parvidural are evidently complementary. (2) The Predural usually refers to the one or more slight branches of the ethmoidal arteries, supplying the adja- cent dura of the precranial fossa. 3. Branch from the Vertebral.—The Postdwral artery arises opposite or just below the occipital foramen, passes with the vertebral into the cranial cavity, and supplies the dura of the postcranial fossa, especially the posterior portions, as the cerebellar falx, etc. The only anastomoses of special interest, between dural and extradural arteries, are with those of the orbit. Such connections always exist. Often a medidural branch enters, through either the sphenoidal foramen or some special opening, and supplies the external wall, even substituting partly or wholly the lachrymal artery, or a branch of the lachrymal may take the reverse course. Very rarely the medidural arises directly from the oph- thalmic (Zuckerkandl, four cases, Hulston, one), and then passes by the sphenoidal fissure to its usual distribution. ‘This possible origin should be borne in mind in the rare operation of tying the medidural at the base of the skull. II. Inrrinstc ARTERIES (or those of the pia and brain substance).—In removing the brain from the skull we sever at its base the four arteries which suffice for its entire blood supply. These are, anteriorly, the two car- otids entering through the carotid foramen and canal, posteriorly, the two vertebrals entering beside the foramen magnum. By means of communicating branches at the base of the brain—the vertebrals having first united, and their common basilar trunk having divided into the two postcerebrals—the primary vessels combine to form the circle of Willis. From this practically all and only the cerebral arteries emanate. Previously, however, several branches are given off by the vertebrals and basilar; while the carotid yields only the ophthalmic. The latter is said always to originate before any of the cerebral branches, and some millimetres before the bifurcation of the cerebral carotid. 250 The Vertebrals and Basilar supply in their course the organs of the posterior fossa, viz., cerebellum, pons, oblongata, and their adnexa. In approaching the distal border of the pons the vertebrals unite to form the mesal basilar. This is occasionally divided within by a septum, or separates into two vessels which soon reunite. The basilar lies in the median sulcus of the pons, directly on the basilar process of the occipital bone ; opposite the central border of the pons it ends in the two postcerebrals. Only occasional variations are attributed to the vertebrals: (1) absence of one, the existing vessel being joined by a branch from the opposite carotid; (2) both may join the basilar on the same side; (8) or one may be represented by two or three branches before entering the formation of the basilar trunk. The lateral branches are: 1. Postcerebellar, the largest offshoot of the vertebral. It passes around the oblongata, beside the pneumogastric nerve, to supply the extremity of the cerebellar lobe as far as the median line, the subvermis and adjacent sur- face, and the plexus of the metepicele. 2. Recurrent Spinal Twigs, also from the vertebral, are given as follows by Kadyi: Immediately after the vertebrals traverse the dura there arises from each a 1 mm. thick branch (dorso-myelic), which, after giving up twigs to the restiform body, descends along the dorsal border of the lateral columns of the cord. This is homol- ogous with other branches entering by the dorsal nerve roots. Sometimes this arises from the vertebral in com- mon with the postcérebellar. Near the union of the vertebral to the basilar there arises—usually one on each side, though unequal—the myelic branch for the ventromyel. These two, how- ever, either soon or oftener after entering the spinal canal, combine to form the azygoid ventro-myelic artery. They are thus continuousand homologous with the other myelic arterioles coming in along the ventral nerve roots. A full consideration of the minute details of the arterial distribution in the oblongata is given by Adamkiewicz (vide Plate XVII.). These vessels come wholly from the upper (intracranial) part of the vertebrals as they cross the ventral surface of the oblongata. The main facts regarding the three classes of secondary or nutrient arterioles (external or surface vessels) he ac- cepts from Duret: 1. The radicals, direct from the verte- brals, supply the outgoing nerve roots (facial, acoustic, glosso-pharyngeal, vagus, accessorius, and hypoglossus). 2. The nuclears, at right angles from the one or two dorso-myelics in an extent of 3 to4cm. These pene- trate the median fissure, at the bottom of which they form a kind of sagittal leader, and end beneath the floor of the metepiccle (fourth ventricle). 3. Arteries for the other portions of the oblongata (olivary bodies, pyramids, corpora restiformia), in part at least from the myelics. Moreover, on the oblongatal surface is a rich network of vessels. The ventromyelics opposite the oblongata give off a multitude of twigs that take a very sinuous course and soon settle into the furrows. For the dorsal surface of the oblongata there is no external supply until below the calamus—upper end of myel. Its source is the dorsomyelics. These latter, at the first cervical roots, turn caudad between the accessory nerve roots (nearer the dorsal), and when at the level of the fourth or fifth cervical roots they end by also anastomosing with vessels of lower origin. From the middle portion of the vertebrals, between the ventro- and dorso-myelics, arise the largest branches (subcerebellars), but these dodge the oblongata and are wholly for the cerebellum. Topographically, Adamkiewicz distinguishes three sets of finer or nutrient arterioles (internal or substantial ves- sels) after the manner of the myelic supply. (1) Ventro-fissurals, relatively large, dividing in the ventral commissure into two branches, one to each side for the corresponding ventro-mesal cinerea. In the ob- longata these supply principally the pyramidal tracts and decussation, lemniscus, interolivary tract, raphé, and the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, following nuclei—gray dorsal columna, n. pyramidalis, n. arciformis, oliva, and hypoglossus. (2) Dorso-fissurals, of course only caudad of the cala- mus. These divide at the dorsal commissure into two border vessels, and are for the substance of the dorsal columns, nucleus gracilis, accessorius centre, and casu- ally the hypoglossus. (3) Coronal, radial, or lateral system. These are very numerous, penetrate the alba from all sides (excepting of course the metepicele), and in part reach the subjacent cinerea to then help form its mass of capillaries. A sub- class here—nuclear arteries—consists of six to eight rela- tively large twigs entering the angulus restiformia oliva- ris and running parallel toward the middle of the floor of the metepicele, to supply principally the centres for glosso-pharyngeus, vagus, hypoglossus, and acusticus. The following parts receive these radial or lateral afflu- ents—the ventral columns, lateral nuclei, lateral cornu, caput of substantia gelatinosa, nuclei cuneati gracilis, ar- ciformis et pyramidalis, and the oliva itself. 3. Medicerebellar, usually from the basilar trunk. This passes along the middle cerebellar crus to the preventrad surface of the respective cerebellar hemisphere, including the flocculus. 4. Transverse branches, three or fourinnumber. These are parallel and accessory to the preceding. 5. Auditiva Interna. Starts like the last, but passes to the internal auditory meatus and structures of the inner ear. 6. Ponticular branches. These immediately enter the pons perpendicularly, and supply its substance. They represent true terminal arteries (Heubner), quite com- parable to the perforants of the cerebrum. From the importance of the tracts supplied they have likewise great interest to the pathologist. 7. Supercerebellar. This starts near the end of the basilar, passes outward along the front border of the pons, winds around the crus cerebri near the optic lobes, and is distributed to the supervermis and general dorsal surface of the cerebellum: It also supplies the post-optic arteries. The basilar branches all emanate at practically a right angle to the mother trunk. Those going to the surface anastomose much more freely than do the cerebral arteries. Accordingly Heubner found the pia districts of single arteries much less definite over the cerebellum than over the cerebrum. Moreover, the branches of the two sides communicate dorsad across the median line; this is explained by the development of the cerebel- lum from a single median vesicle. The only communi- cation between this system of vessels and the cerebral— except through the basilar trunk—is by small branches of the precerebellars and postcerebrals across the crura cerebri. CrRcLE oF Wiuuis.—The carotid ends at the outer angle of the chiasma in two main branches, the pre- and medi-cerebral arteries. At about 1 cm. in front of the chiasma the two precerebrals are connected by the pre- communicant. From either the medicerebral or the carotid passes the postcommunicant to the corresponding postcerebral. Hence the circle (or polygon) of Willis is made up by one precommunicant, two precerebrals, two medicerebrals (or two carotids), two postcommunicants, and two postcerebrals. This is the classical arrange- ment; fromit, however, there are frequent and important deviations. Professor Windle found that it held in only 76, or, overlooking any disproportion in the postcom- municants, in 119 out of 200 cases. Only in the apes do the vertebrals nearly equal the carotids. In man, Ehr- mann, from 157 measurements, found that very constantly the basilar trunk was equal to one carotid (7.e., furnished one-third of the brain supply). The communicants are not simply to re-establish a circulation in case of obliter- ation, but they normally act to equalize pressure in the local vessels. When this circle is complete and of normal structure, an adequate collateral circulation is established after occlusion of any one part. From this circle and the first few centimetres of its branches originate a multitude of arterioles passing to the basal ganglia and adjacent structures. Dercum offers “ A Collection of Anomalies of the Circle of Willis” (Jowrnal of Nervousand Mental Diseases, 1889, January), and J. H. Lloyd (Jdzd., 1890, p. 225) gives such a case of a type described by Duret (right vertebral absent, both precerebrals from left carotid, etc.). St. John Bullen (Journal of Mental Science, 1890, January, p. 38) bases the following statements on the examination of 1,565 brains (from the insane), but holds statistics too uncertain. Arterial variations occur much oftener in general para- lytics than in those dying of other forms—this applying equally to all segments of the circle of Willis. The components of this circle and their branches: The Precommunicant.—This is a transverse branch beneath the rostrum, from 1 to 2 mm. in size, connecting the two precerebrals, and forming the anterior side of the circle. Windle found it normal in 159, double in 14, in- completely so (forked at one extremity) in 6, triple in 1, absent in 8, and associated with union of the precerebrals in 2. Wilder notes the latter condition in 6 out of 7 cases, and Starrin 2of 14. Duret says that when double one is of normal size, the other very small. Its place is sometimes supplied by a fasciculus of small twigs. The precommunicant, Bullen finds, may be absent, or merely rudimentary, or double. Its branches—more numerous when the communicant is unusually long—are: 1. The Termatica, a mesal vessel at its origin. Wilder found this present in all of seven brains examined. “It usually divides soon into a right and left portion, which supply respectively the cinerea forming the surface of the triangular area ventrad of the genu and rostrum, and then extend around the genu to the dorsal aspect of the callosum.” Windle notesitin nine of hiscases. It passed along the longitudinal fissure for two-thirds of the length of the callosum, and divided into branches supplying the opposed surfaces of the hemispheres. When the com- municant is wanting, this vessel may start from the junc- tion of the precerebrals. 2. Small retrograde rami to the lamina of the chiasm. 3. Arterioles which plunge into the callosal rostrum, and very often one or two considerable branches com- pletely perforating the rostrum and ramifying on the crura of the fornix, the anterior commissure, and the septum. The Precerebral (vide Plate XVI. and Fig. 818, 3).— This at its origin is almost perpendicular to the carotid. Often the artery of one side is larger than, and partly substitutes, that of the other side. Windle found it nor- mal in 181 of 200 cases. In 2 the right was absent, its place being partly supplied in one by twigs from the right medicerebral, in the other by a small branch from the carotid. In1the right was double the size of the left; in 1 the two united to a single trunk; and in 8 they united for a short distance, six times replacing and twice accompanying the precommunicant. Hither precerebral may, according to Bullen, (1) be replaced by two small trunks; or (2) be absent, its region being supplied by branches of the opposite artery. The short oblique portion, dorsad of the optic nerve, between carotid and precommunicant, represents part of the circle of Willis. This portion may give off the fol- lowing branches: 1, Arterioles to the optic nerve of the same side. 2. Lateral arterioles to the neighboring con- volution and the callosal rostrum. 38. When, from pre- mature division of the carotid, the precerebral goes over a longer course, it much oftener gives large twigs to the caudate ( preperforantes). Duret says that these branches take one of two courses. In one they penetrate almost within the expansion of the olfactory nerve, perforate the callosum at its junction with the lower part of the caudate head, and divide into five or six almost sub- ependymal ramifications not extending ‘beyond the first 2 cm. of the caudate. In the other, one or two arterioles, of about 1 mm. diameter, follow a retrograde course of 3-4 cm. to the preperforated space beneath the caudate, to which latter exclusively they are distributed. From the precommunicants on, the precerebrals run 251 Brain, Brain, side by side around the genu and caudad at the bottom of the longitudinal fissure. After giving off the first few branches the main trunk may divide into three branches, as stated by Duret, whose description is largely followed; or several successive branches are given off, as in the accompanying plate. Together, they supply the inner two-thirds of the ventral surface of the frontal Fig. 818.—Arteries of the Base. (After Duret.) prethalamic (postperforants). vian fissure, and also its branches crossing the insula. lobe, the anterior four-fifths of the opposed surface of the hemispheres, the callosum (largely), and a portion of the convexity. 1. Subfrontal twigs, to the olfactory groove and region as far as subfrontal sulcus. 2. Prefrontal branch, to mesal surface of superfrontal and convex surface of superfrontal and part of medifrontal convolutions. 3. Medifrontal branch, to the callosal convolution, and paracentral lobule. After doubling the crest of the hemisphere it terminates about the dorsal extremity of the central fissure. 4. Postfrontal branch, to precuneus and the adjacent portion of the convexity, nearly or quite reaching the occipital fissure. 5. Cullosal artery. This may pass around the splenium to terminate in the pineal gland, and even posterior commissure. It goes to the callosal convolution and vault, perforating the latter and ramifying over the whole extent of the roof of the paracceles. The Cerebral Carotid (Fig. 818, 1).—As a rule the post- communicant is a direct branch of the carotid, though it often starts from the medicerebral. In the former case the carotid, from this branch to its termination at the 252 1, Carotid ; 2, medicerebral ; 3, precerebral; 4, postcerebral; 5, preperforants (striate arteries) ; 6, prechoroid; 7, postcommunicants ; 8, postchoroid ; 9, medichoroid ; 10, callosals (termination of precerebrals) ; 11, medioptics ; 12, The carotids are drawn frontad to show the preperforants. The left temporal lobe is cut away, exposing the medicerebral trunk at the bottom of the Syl- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. commencement of the Sylvian fissure in the pre- and medi-cerebrals, forms part of the circle of Willis. In this short course a few lateral branches are given off: 1. Arterioles to the external angle of the chiasm. Either these or the chtasmie arterioles from the precere- bral supply minute twigs to the first portion of the optic nerve. 2. Frequently, one or more of the perforantes to the caudate. 38. Prechoroid (Fig. 818, 6). This may come from the medicerebral, or even from the postcommunicant; in any case its origin is peripheral to that of the last named. It is directed oblique- ly caudad along the outer side of the optic tract to attain the cho- roid plexus in the lateral horn (through the extremity of the transverse or Bichat’s fissure). It gives off: (@) internal and slightly recurrent branches to the optic tract; (0) internal branches for the central part of the outer aspect of the crus cerebri; (¢) external branches to the uncus (a terminal arteriole, Heubner); (d) extremely fine twigs to the two-thirds of the choroid plexus that it is stated to traverse. In general, Kolisko’s work cor- roborates that of Heubner. Ina large number of examinations this vessel was never absent. It hasa pretty constant diameter of 0.5 mm. In the foetus it is relatively very large. In animals (dogs, cats, rabbits) it was regularly pres- ent, but arose from the Sylvian. The branch to the uncus was al- ways present, but has free anasto- mosis in the pia. The branches in plexus and tela also anastomose freely with others near; but those rae brain substance are termi- nal. The prechoroid supplies the fol- lowing parts: The posterior arm of the internal capsule, with the lamina medullaris externa of the thalamus to the level of the upper angle of the midlenticular seg- ment—usually only the posterior two-thirds; the white substance back of the internal capsule as far as the roof of the medicornu; the inner lenticular segment; the un- cus; the optic tract (in its pos- terior half); the lateral choroid plexus; the endyma of the posterior and lower parts of the paracele; the greater part of the tail of the caudatum; exceptionally the external parts of the upper half of the thalamus. But the posterior arm of the internal capsule is also in part supplied by the medicerebral and posteommunicant (the anterior third of this part by the latter vessel), the deeper parts by the prechoroid and postcommunicant, and the upper parts (above apex of midlenticular seg- ment) by the Sylvian (lenticulo-optic ramus of Duret), Circulatory disturbances in the supply territory of the prechoroid cause opposite hemiplegia by softening in the posterior segment of the internal capsule, involving the pyramidal and cranial-motor tracts. Hemianesthesia, hemianopsia, and hemianosmia may likewise follow closure of the prechoroid, but are usually headed off by collateral supply. When the postcommunicant is large, its blocking may cause opposite facial and hypoglossal paralysis, since these tracts traverse the front part of the posterior arm of the capsule. The Medicerebral (vide Plate XVI. and Fig. 818, 2).—The- EXPLANATION OF PLATE XVI. | fs sd as . . 4 . “% + te + - J a 7 s « . t U » e _ " ty =? ® s . . a a an Fx; is EXPLANATION OF PLATE XVII. ARTERIAL SUPPLY OF OBLONGATA (FROM ADAMKIEWIOZ), ENLARGED Srx DIAMETERS. Fia. 1.—At Decussation of Pyramids. Hs, Dorsal Column. Ng, Nucleus gracilis. Ne, Nucleus cuneatus. Sge, Substantia gelatinosa centralis. Cep, Caput cornu posterioris (aut tuberculum Rolando). AIT, Root of hypoglossus. Vr, Remnant of ventral column. Prk, Decussation eminence. Py, Pyramid. g, Boundary between Py and Vr. S, Arteria sulci. Sa, A. sulci (at deeper layers). Acc, Aa. centrales cornuum anteriorum. Aca, Aa. cornu anterioris. Anl, A. nuclei lateralis. As R, A. tuberculi Rolando. Anc, A. nuclei cuneati. Ang, Aa. nuclei gracilis, F, A. fissure. Fie. 2.—Opposite Middle of Metepiccele. H, Hypoglossus nucleus. Va, Post. vagus nucleus. Po, Ponticulus (velum medullare posticum). Gi, Glossopharyngeus nucleus. Ac, Acusticus nucleus. Ib, Longitudinal bundle. (Krause’s respiratory fasciculus.) Cr, Corpus restiforme. X, Ant. vagus nucleus. IX, Root of glossopharyngeus. Aro, Angulus restiformio-olivaris. O, Oliva. No, Nucleus pyramidalis. Ozs, Interolivary tract. R, Raphé. Py, Pyramid. Na, Nucleus arciformis. S, Arteria sulci. Sce, Affluents to external nest-like capillary coils, from. sulcus artery. Sci, Affluents to inner same. Aoli, Sublateral olivary artery. Aso, Olivary ramus from sulcus artery. Aoli, Subolivary arteries. Aolm, Medilateral olivary artery. Aols, Super-olivary artery. An, Arteries of the nuclei (glossopharyngeus, vagus, hy poglossus). Vn, Nuclear vessels (glossopharyngeus, acusticus). F, Arteria fissure. Fie. 3.—Longitudinal Section through Olivary Body. O, Oliva. Br, Pons. Aoli, Aa. olive laterales inferiores. An, Aa. nucleariz. EFERENCE HANDBOOK | | , Plate XVII. moe OFTHE : -* MEDICAL SCIENCES. a %, a 7 . TABOR? Us, ‘ pee My ACN ; eee AVA TIA a 4 Fas ‘Ge a) --= g OS ee : sites SE me Dra a Cal ear yt AOR cM or DUNE GN ee e Br a ae ere ee Arterial Supply of Oblongata (from Adamkiewicz |) Libr °7Y OF [HE UNIVERSITY of ILLINOIS. > REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, vessel represents the most direct continuation of the cere- bral carotid. It lies at the bottom of the Sylvian fissure, as do also the primitive portions of its larger branches as they spread out over the insula. When the postcom- municant starts from the medicerebral, the previous short (4-6 mm. long) portion of the latter participates in the circle of Willis. No branches are assigned to this art. : The medicerebral in its further course yields two classes of branches: (a) direct, perforating, or nutrient arterioles ; (0) large and small pia arteries. (a) A few perforantes (Fig. 818, 5, 5) from the earlier part of this artery may pass directly to the caudate head, with those described under precerebral and mentioned under carotid. Butthe main group from this source take a somewhat different course, and, as stated by Heubner, are often detached from the trunk farther out in the fissure. These have been divided into two sets. The first to leave the trunk—lenticular arteries—are the finer, and are simi- lar in deportment to the preceding, except that they go to the first and second segments (apex) of the lenticular nucleus. The second, coarser set runs along the base of the lenticular nucleus on the limit of the external cap- sule. A portion of these pass caudad and dorsad to the thalamic extremity of the lenticular nucleus, and termi- nate in the thalamus—lenticulo-thalamic arteries. One arteriole, noticeably larger than any of the others and the frequent source of hemorrhage in this region, passes dorsad and mesad to the third segment of the lenticular, where it gives off many side twigs, and finally divides into four or five terminal branches, supplying also the adjacent internal capsule, etc. Two or three accompany- ing arterioles extend toward the third segment, and may attain the tail of the caudate. Collectively these are termed lenticulo-striate arteries. A further group might be made of the small direct vessels traversing the insula to gain and supply the claustrum ; as this is, however, a derivative of the ex- ternal gray layer, these twigs more nearly correspond to the general cortical and albal arterioles. Of the perforantesas a whole, it may be said that they all emanate at right angles from the inner side of the mother vessel. Their size varies from 0.5 to 1.5 mm. They immediately enter the brain substance, only occa- sionally dividing, and never anastomosing before doing so. They usually run a further short course before branching. The ultimate distribution of each is pencil- shaped. They are destined to supply the central gray nuclei and the capsules, notably the inner. They are all true terminal arteries, without any anastomoses either between themselves or with other arteries. According to the French school, even their finest capillaries do not con- nect, but on this point the Germans teach otherwise. (6) Pia branches of the medicerebral. After a course of 1 to 2.5 cm. the main trunk, either at one stroke or successively, divides into several large branches. 1. Previously, however, there are usually a few small rami for the adjacent borders of the frontal, and especially the temporal, lobes (see Plate XVI.). 2. Frontal branch. This is generally the first large ramus. Like the succeeding, it runs some distance deep in the sulcus and subdivides often, at least before ap- pearing externally. It is especially destined for the subfrontal convolution. It supplies the orbital surface of the frontal lobe external to the orbital fissure, and the convexity dorsad to the middle of the medifrontal gyrus, caudad to the precentral sulcus. Duret found a very ent corresponding artery in several species of ani- mals. 3. Preparietal. This nourishes the precentral and ad- jacent extremity of medifrontal convolutions, and may by an early branch include the postcentral also. 4, Mediparietal. Thismay gain the fissure of Rolando to supply not only the postcentral convolution, but dorsad a portion also of the precentral. It may also reach the adjacent parietal region. 5. Postparietal. This is a large branch in the horizon- tal Sylvian fissure. Its ramifications do not extend be- yond the parietal or occipital fissure, but may pass be- yond the supertemporal. 6. Temporal. This is included under the last by many, but it is often an early and large branch of the medicere- bral. By its numerous considerable subdivisions it then covers practically the whole external temporal surface. At least the supertemporal convolution and much of the meditemporal are regularly supplied. Its distribution extends nearly to the suboccipital convolution. There is no special artery for the insula, but it receives several small branches from the preceding as they cross it. The Postconmunicant.—Connecting the pre- and post- (carotid and vertebral) systems. They start from the carotid or medicerebral, and run directly caudad to in- osculate with the corresponding postcerebral at 5-12 mm. from the latter’s origin. They pass ventrad of the optic tracts and also encounter the crura cerebri. In size and occurrence these vessels are variable, and fre- quently unsymmetrical. The left is more often the smaller or even absent, though some filiform anastomosis from a corresponding branch of the carotid usually does exist. As a very large branch from the carotid, espe- cially the right, it may replace the corresponding postcere- bral wholly or in part, or conversely; a large left com- municant has been observed to arise from the postcerebral and supply the same medicerebral. Aside from disparity in size (43 times) the postcommunicants were normal in 175 of Windle’s cases. Excepting slight anastomosis, both were absent in 8 cases, the right in 9, the left in 13. In 7 both were very small; in 28 the right was much larger than the left; in 15 the reverse. Anomalies, says Bullen, are more common in the post- communicants than in all the others. Of these vessels, either (1) may beabsent; (2) may be replaced by a branch from the subcerebellar, internal carotid, postcerebral, or two small nutrient branches respectively from the last two vessels; (3) may supply unusual regions; or (4) may be unconnected with the carotid system. This vessel gives off laterally pia branches, (a) internal, (6) external, and (c) inconstant penetrating rami. (a) 1. Chiasmic branches to the caudal side of the chiasm. 2. Twigs to the tuber cinereum and infun- dibulum, a descending ramus supplying the pituitary body. 3. Two to the mammillary bodies. (0) 1. To the optic tract. 2. To the cerebral crura. 3. Often considerable branches to adjacent temporal gyri. (c) 1. Prethalamic Artery (internal and anterior optic of Duret). It penetrates between the tuber cinereum and mammillary bodies, and ramifies in the more anterior part of the aula, on the walls of the infundibulum, etc. 2. Medithalamic artery (posterior internal optic). At times large, it enters the postperforated space and passes directly dorsad near the inner thalamic wall, to which and the gray commissure it is distributed. This vessel comes as often ‘from the postcerebral as from the post- communicant. The prethalamic may also have the same origin. The Postcerebrals, from the end of the basilar to the postcommunicants, complete the circle of Willis. This part furnishes: (1) three or four arterioles to the internal aspect of the crura cerebri, supplying its basal layer, the locus niger, etc.; (2) little branches entering the thalamus through the postperforated space. These accompany, and often include, the above-described medithalamic artery. Windle found the postcerebral arteries normal in 173 cases. The vessel was derived from the carotid instead of the basilar in 11 cases on the right, 9 on the left, and 4 on both sides. There were 2 postcerebrals on the same side—the smaller from the basilar, the larger from the carotid—in 3 cases: 1 on the right and 2 on the left. Either of the postcerebrals may (Bullen) (1) be absent; (2) be a branch of the carotid system; (3) be replaced by a large postcommunicant; or (4) be replaced by two thread- like vessels from the basilar. This trunk, in passing around the crus, describes a kind of semicircle, directed toward the transverse fissure. Dorsad of the crus, at about 1 cm. from the optic lobes, 253 Brain. Brain, it turns latero-caudad to gain the calcarine fissure, where it breaks up to supply the basilar postcerebral region. From its crural portions it supplies, besides other branches, nearly all the nutrient arteries of the ceelian walls. 1. Little twigs to the outer part of the crus, penetrat- ing almost immediately. Instead of several in the thala- mo-crural sulcus, there may be a single larger one, par- allel to the main stem. 2. The fairly constant Medioptic (median quadrigem- inal), giving fine offshoots in its course to the crus, and terminating in a bunch of fine vessels in the interval of the optic lobes. 3. Postthalamic (so-called posterior and external), two or three, or a single larger one, starting midway from this portion of the postcerebral, and following the crus to enter the thalamus between the geniculate bodies. 4 Geniculate, emanating directly, or from the thalamic. 5. Postchoroid (posterior and lateral), starting near the optic lobes, and entering between the layers of the velum. It always divides into two principal rami: a lateral one for the third of the choroid plexus not supplied by the prechoroid artery, ¢.¢., for the plexus over the thalamus; the other more median one for the velum (ramus velaris). 6. Medichoroid (posterior and median choroidal), from the postcerebral at its nearest approach to the median line. It courses beside the conarium, to which it yields some rami, and immediately divides into two branches, one to the velum of the aula, the other exclusively to the choroid plexus of the same cavity. . The choroid plexi and velum represent a double layer (fold) of the pia, within which the ccelian arteries and veins course. Duret states that in all the ceeles the arte- ries to the velum are distinct from those to the plexus, often even from their origin at the postcerebral, and al- ways at their entrance into the corresponding cavity, and that they never mingle in their distribution. From the velar arteries are detached a multitude of little arterioles, which penetrate the thalamus 1 to 1.5cm. They have the arrangement of cortical arterioles, and are pencillated. The two velar branches terminate in the head of the cau- date, either simply subependymal or passing deeply into its substance. The velar branches to the aula emit little arterioles laterally at intervals of about a millimetre. These penetrate perpendicularly the adjacent wall. They supply also the posterior and gray commissures, and terminate in a fine pencil in the anterior commissure. The plexus arteries, on the contrary, do not usually participate in the nutrition of the celian walls. They divide into four or five long parallel branches from which little arterioles pass into the plexuses, properly speak- ing. They enter the little tufts by their base, and form very attenuated and sinuous capillary meshes. It has been suggested that they are the remains of former branches ramifying in the embryonic ccelian pia, and that they became coiled up when this membrane retracted. 7. Preoptic (anterior quadrigeminal), very short, com- ing from the most median part of the postcerebral, or from some branch of the latter. It forms a very delicate pencil over the preoptic body. This makes the third pretty constant pair of optic arteries, as these lobes are very vascular. They have some anastomoses across the median line. 8. Artery of the cornu Ammonis, oftener from some branch of the postcerebral than arising directly. It does not ramify on the ccelian surface, but passes between the Ammonshorn and the hippocampal convolution, to trav- erse the cortex in the manner of external arteries. 9. Variable branches to adjacent temporal gyri. Final Divisions of Postcerebral.—These may be brought under three general heads (see Plate XVI.). 1. Pretemporal branches to the uncus in part, and the basal surface of the temporal lobe as far as the border of the convexity, except the third nearest the apex of the lobe, which is supplied from the medicerebral. 2. Posttemporal to the basal surface of the occipital lobe, including a variable amount of the adjacent tem- poral region, and doubling the border of the convexity 254 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. to supply a little of the external occipital region. The hippocampus may be supplied from the parent stem, or from either 1 or 2. P 3. Occipital artery. This runs along the calcarine fissure, sending a large branch through the occipital fissure; it supplies the cuneus and general median sur- face of the postcerebral lobe, and a considerable strip of the adjacent occipital convexity. Spitzka says that an artery large enough to cause fatal hemorrhage enters the: gray and white of the right occipital lobe. GENERAL FEATURES OF THE ARTERIAL SUPPLY.— The distribution of each primary trunk includes: (a) bas- ilar or nuclear branches; and (4) pia or cortical branches. (a) These are the pre- and post-perforating and ccelian. arteries, arising in part from the circle of Willis. They supply the central ganglia, coelian structures, and in part the centrum semiovale. To the same class belong the direct arterioles from the basilar to the nuclei in the pons. Excepting occasional and unimportant anastomoses, these are all true terminal vessels. They divide within the brain substance at an acute, and not a right, angle. (6) The pia branches or divisions as described are only averages, complementary variations therefrom al- ways being present; though it is claimed that while “their origin is often very variable, their distribution is constant.” The larger arterial trunks correspond to the main fissures. To a marked extent it is true that the same branch does not supply both sides of a sulcus. Branches usually leave the parent stem at almost or quite aright angle. Some writers try to show a freer supply to the left hemisphere. Duret’s attempted correlation of arterial distribution and physiological function was at. least premature (1877) and faulty. Anastomoses.—The basal circle of Willis comprises all the communications readily demonstrable on the unin- jected pia arteries of the cerebrum. Only within this. circle and over the optic lobes are there any minute con- nections across the median line of the hemispheres. There has been a dispute as to the extent to which the ramifications of adjacent branches on either hemisphere are connected. Duret, after numerous, varied, and evi- dently careful examinations, says: “Never have we found an anastomotic network in the pia.” He also notes the frequent superposition in the pia of fine arterial ramifications. Nevertheless he found considerable in- dividual differences, and regularly some fine (0.2 to 0.25. mm.) communications, especially at the periphery, 7.¢., be- tween adjacent territories of distribution. On p. 927 he acknowledges that in the great majority of cases, owing to anastomoses, “however rare and unimportant,” softening from occlusion of any of the large basilar trunks spares. the peripheral parts of the artery’s territory. In the four-months foetus he found abundant fine anastomoses. Heubner (p. 174), on the contrary, says: “The chief [pia] branches end in a kind of communicating canal system or reservoir, which is spread out in the shape of a tubu- lar net over the whole surface of the brain.” By inject- ing “under weak finger pressure” he found plentiful anastomoses up to 1 mm. in diameter. Heubner’s de- scription harmonizes with that of older writers, and is corroborated by Lucas, who by sufficiently penetrating injections was able to demonstrate an abundance of com- municating arterioles up to 0.25 mm. (vide Plate XVIIL., Fig. 2). It remains true, however, that when the com- municants of the circle of Willis are poorly developed, the peripheral anastomoses are, in a large number of cases, incapable of substituting them. Direct or Nutrient Arterioles of the Convolutions.—These emanate at right angles from the pia branches, of all sizes. They penetrate the crests of the convolutions perpendicularly, the inclined surfaces obliquely. They are innumerable—scarcely more than 1 mm. apart. Ac- cording to size and distribution there are two classes: 1. Cortical, 0.05 to 0.08 mm. in diameter. The finer stop in the cortex proper; the others go to the boundary of gray and white. The capillary network from these rami has been divided into three somewhat differently characterized layers, each parallel to the rolling surface. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. 2. Albal (arteriole longs), 0.08 to 0.14 mm. in diam- eter. These are almost rectilinear, can be followed a distance of from 3to4 cm., and branchat an acute angle. They supply a considerable portion of the centrum semi- ovale. One often passes down along the axis of the con- volution. A group of five or six at the bottom of a fissure (in section) diverge on entering. The capillary network of the albals is more elongated than that of the corticals, and accompanies the fasciculi of nerve fibres. Both classes anastomose freely in their finer branches, though in general pencillate. From the anatomical arrangement it is believed that the intravascular pressure is less in the gray than in the white substance. It has been claimed by many that the thyroid gland acts as a safety diverticulum to the cerebral supply; and furthermore, that the lack of this regulator explained the occurrence of so-called cachexia strumipriva after removal of that gland; but any such special function of the thyroid is at least not proven. Width of Brain Arteries.—To make a relative estimate of the capacity of the arteries at the base, Bevan Lewis (“Examination of Brain,” 1882, pp. 20-22) determined their average diameters in 45 cases (insane). That of the vertebral was, r. 3.147 mm., 1. 3.42; of basilar, 3.82; of postcerebral, r. 2.658, 1. 2.56; of carotid, r. 3.951, 1. 4.02; of medicerebral, r. 3.138, 1. 3.55; and of precerebral, Te 2.78, 1. 2.66. The sectional areas are of course propor- tional to the square of these diameters. Asa rule, the united areas of branches equal very nearly the area of the parent trunk—excepting the preponderance of the vertebrals over the basilar (22.4 to 14.8). Loéwenfeld has found that the relation of the artery width to the brain weight is, even normally, somewhat variable, and that often, though not by any means in all cases, the width of the brain vessels rises and falls with the width of the aorta; moreover, that not rarely abnor- mally small brain arteries occur in otherwise well-devel- oped arterial systems. He also made out a difference in the two sides, the left carotid being usually wider than the right. Pressurein the Brain Arteries.—A further matter, noted by St. John Bullen (oc. czt.), may partially indicate the rel- ative pressures in the main brain arteries. He remarked atheroma of the basal vessels in 410 of 1,565 autopsies, or 26 per cent. of the total. It was present to a consider- able extent, either generally dispersed or in special trunks only, in 175 cases, and to a less extent in 2385. The relative frequency by location was: medicerebral, 38 per cent.; basilar, 80 per cent.; postcerebral, 21 per cent. ; carotid, 10 per cent. Mendel (1891) has found experimentally that the press- ure in the cortical arteries is materially less than that in the carotids, while that in the striatal arteries is not materially less. This he attributes to the fact that the latter are terminal vessels, though it is doubtless quite as much due to their less circuitous supply. He further thus explains the frequency of hemorrhage in the striatal region. Tedeschi’s conclusions regarding the brain arteries refer in part to moot points, but really contain nothing new and are deceptive in statement. VEINS. The venous passages of the pam and its membranes include: I. The dural veins. II. The intrinsic veins, or those of the brain proper. III. The sinuses. IV. The venous exits from the skull. All the intrinsic and most of the dural veins discharge into the sinuses, or appendatory spaces, which in turn convey the plood to the exits. ‘Otherwise these two sets of veins are separate systems, not interanastomosing, unless occasionally near their mouths. The intrinsic veins without exception have thin, readily collapsing walls, while the sinuses are held open by the firm enclos- ing dura. Brain, Brain, all these vessels are devoid of muscular elements, though occasional unstriped fibres have been observed in the in- trinsic veins. From this absence of actively contracting fibres, it follows that these vessels play a merely passive role in the encephalic circulation. The encranial veins, like the external veins of the head, are devoid of true valves. However, at the orifices of the diploé veins (Dupuytren, Langer, doubted by Trolard) and in the ophthalmo-dural vein, valves may occur. It hasalso been claimed that the supercerebral veins in part present a valvular arrangement at their discharge into the longi- tudinal sinus.. The general impression that valves never occur in any of the veins above the common jugular is therefore incorrect. I. VEQUNS OF THE DuRA (including those of the diploé). —These are many in number, but all of small size. They anastomose so freely that they might almost be de- nominated a plexus. In position they are comparable to the plexus venosus existing between dura and periosteum of the spinal canal. In their ultimate distribution they form two vascular nets, according to Langer, one in the outer, the other in the inner, layer of the dura. The beautiful, almost regular, interlacing of the former, figured by Langer from the fcetus, the writer is able to corroborate. By means of small veinlets penetrating the inner plate of the skull, the dural veins communicate ex- tensively with those of the diploé. They include: 1. Medidural, or Vene Comites, accompanying the medidural artery and its branches. The two on either side of an artery repeatedly connect with each other and with neighboring veinlets. The largest pair is about the common trunk of the artery. One of these passes ex- ternally through a basal foramen to the pterygoid veins. The other ends in the medicerebral vein or its temporal sinus, or directly in the sphenoidal or cavernous sinus, with which latter it usually at least connects. The diploic canals have some special openings into the larger medidural veins. 2. Superdurals. These appear in part as direct con- tinuations of the preceding, and then are double. They pass to the longitudinal sinus, largely through the inter- mediation of its lateral spaces. Labbé suggests that the supra- and medi-dural veins may constitute a small col- lateral path between the long sinus and basal conduits. 3. Faleial Trunklets (Fig. 819, &), ranning to the longi- tudinal sinusand to the falcial sinus when present, other- wise to the tentorial. The tentorials go to the lateral and tentorial sinuses, also in part by way of the parasinual spaces. 4, The numerous veinlets for the other dural arteries, é.g., in the occipital fossa, have a more independent. course and end in adjacent sinuses. Venous Canals of the Diploé, even less yielding than the sinuses. Breschet’s description is somewhat modified by Trolard. The diploé is made up of little areole. These canalize in any direction, though in general ventrad to discharge near the base. These canals are quite unsym- metrical, and do not increase in size in their course, ex- cepting where there are casual enlargements; areole, conduits, and lacune are lined with a smooth membrane. Generally the diploé begins to appear about the tenth ear, though small straight veins are evident earlier. esorptiod of the cancelli goes on continuously, and after fusion of the sutures they may pass from one bone to another. In the aged we find a sort of wide-spaced venous plexus, no longer canals. There are several ex- terior outlets and numerous interior ones. Even the one through the supraorbital notch passes to the ophthalmic vein and so to the cavernous sinus. Casual mention will be made of most of the special terminations. II. VEINs oF THE PIA AND BRAIN SUBSTANCE. —From their derivation and discharge, these vessels naturally fall into three classes: A. The supercerebrals, passing to the longitudinal sinus. B. The internal or Galen’s system, tributary to the tentorial sinus. C. Basal veins, ending in the various sinuses of the base. A. The Supercerebral veins return the blood from the In general it may be stated that the walls of | convexity as far as the Sylvian fissure, and from the 255 Brain, Brain, median surface of the hemispheres as far as the super- callosal fissure. There may be a slight interval between the frontal set and the others, or a smaller vein may here occur; otherwise they are all fairly equidistant. There are usually six to eight large trunks on each side. These veins tend to empty into the sinus in pairs. This is less marked in the frontal set. It is most easily demon- strable in the faetus, owing to theabsence of Pacchionian bodies, or thickening, adhesions, etc., at the border of the convexity. The last pair ends in the sinus some 8 to 5 cm. before the torcular. The second or third pair from the last may be somewhat larger than the others, and then represent the so-called anastomctic vein, though its size is quite as much due to the greater width of the brain in this part. Although Labbe says this vein runs along the postcentral fissure, it is probably identical with Krause’s fetal vena sulci centralis. Moreover, each supercerebral vein is double, also best seen in the feetus. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. sinus, while the others open more and more at the side, and the last quite at the bottom of the sinus, even com- ing up a distance through the falx. Toward their field of derivation these trunks pursue an indifferently parallel course. In general, over the cortical area the finest veinlets are richly distributed everywhere, from the bottom of the fissures to the crest of the convolutions. B. The Internal System, Tributary to the Tentorial Sinus.—Along its course this mesal sinus receives only unimportant, mostly dural, veinlets. At its commence- ment there may be two affluents: (a) the falcial sinus; (0) the vena Galeni. (a) The inconstant falcial sinus also receives only dural twigs in its course, but at its commencement—opposite the frontal border of middle third of callosum—may take up a small vein or veins coming from the frontal third of the callosum, and from the bordering convolutions. Fic. 819.—The Vena Galeni. (From the author’s ** Veins of the Brain,” ete.) The two constituent veins are of unequal size, the larger external one coming from the convexity, the smaller inner one coming from the median surface (of hemi- sphere). They may soon unite to one trunk, but gener- ally, in their further course to the sinus, they lie side by side within a common sheath, and do not lose their in- tegrity as independent conduits until about to open into the sinus. Commonly some of the paired, as well as their constituent double veins, are wanting to complete the diagram. The frontal set take a course very nearly at right angles to the sinus, or the first of them may even run caudad along the sinus before discharging. They usu- ally spring over to the dura a couple of centimetres away fromthe sinus. This point has since been more carefully gone over by Mittenzweig. In 200 cases he found 59 in which the presupracerebals (to only 9 in which the postsupracerebrals) jumped over from the piarachnoid to the dura at 3 to 4 cm. from the long sinus —thus favoring their rupture, as he thinks. Farther along the sinus the veins take a more and more oblique course until they at last run forward a distance of 38 or 4 cm., to discharge against the current. At the border of the convexity, or farther out in the pia, the vein makes the necessary bend to approach the sinus as described. It then runs a short distance in the pia, becomes in the foetus a free trunk for a further short length, and finishes its course in the dura. Again, the frontal set open at the lateral angle of the 256 Labbé calls this the ¢nterhemispheric vein, and says that the 1 to 2 cm. long veinule bifurcates, sending one branch to either side. A parallel term, mesolobica, was given by Breschet to the precerebral vein. (0) Vena Galent. This discharges through a slit in the basal wall of the sinus, just caudad of the free border of the tentorium. The name is now limited to the short (1 cm. long, 6 mm. broad) trunk from the union of the velar veins to the sinus. Within, it is often divided by a longi- tudinal septum. The course of Galen’s vein and that of the adjacent portion of the velars is very peculiar. The vessels sink a little after crossing the optic lobes, then encircle the splenium, and become subtentorial before ending in the sinus. The latter bears the relation thereto of a tangent to a circle (ede Fig. 819). Galen’s vein does not usually receive any lateral afflu- ents. It arises from the union of the right and left velar veins. Each of these consists of two portions, a terminal bent part ( portio curvata, Fig. 820, ¢ c) from the conarium to the vena Galeni, and a peripheral, or ccelian, straight part ( portio recta) from the origin of these veins, opposite the foramen of Monro, The two curved portions start and end together, but midway diverge 0.5 cm.; they re- ceive laterally many large branches. The straight por- tions run parallel and adjacent, but receive only few and small additions. The affluents to the portio curvata are largely of cor- tical origin; (1) v. suboccipitalis; (2) v. supercerebellaris; REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. (8) v. callosalis; (4) v. subcerebralis; (5) vv. optici et conarialis; (6) v. postcornualis. 1. The Suboccipital vein (Fig. 819, }) comes from the collateral fissure and median portion of the suboccipital surface of the cerebrum. 2. The Supercerebellar vein (Fig. 819, h), oftener a single trunk, but occasionally bilateral, empties into the main vein near its termination, or even directly into the sinus tentorialis. It starts from many little branches over the dorsal surface of the cerebellum, the supervermis, and in its further course takes up small veins from the crura cerebri, and at times also from the optic lobes. 3. The Callosal vein (Figs. 819 and 820, g) (first men- tioned by Labbé, 1879, then independently described by the writer in 1884) may be either single or bilateral. It is a small but long vessel, and the only one emptying on the concave side of the portio curvata. Its origin is near the middle of the callosum, and dorsad as far as the cal- losal fissure. It runs caudad at the bottom of the longi- tudinal fissure, and curves around the splenium close to Galen’s vein. In animals (sheep) its size almost equals that of Galen’s vein. 4. The Subcerebral (Fig. 819, e) is a large vein, though its derivative territory is very variable. It forms by the union of many branches—collectively termed Prebasal Veins—opposite the preperforated space. The prebasilars include the first five next following: (1) The Precerebral vein takes nearly the same path, but is too small and uncertain to be well compared to the precerebral artery. Itsderivative area is very much less. It comes around the genu to the base, where it passes before the chiasm to the subcerebral vein. The right and left are usually of unequal size, but communicate, though by an insignificant branch compared to the arterial precommunicant. The two veins may also unite before the chiasm and pass to one of the subcerebrals, in which case there are one or more slight connections in front of the chiasm with the other subcerebral vein. This vein receives branches from the genu and adjacent median frontal surface. (2) The Olfactory is a tiny veinule, very constant, and demonstrable as far as the olfactory bulb. (8) Subfrontals. One of these is frequently more de- veloped, and may empty instead directly into the Sylvian or the medicerebral vein. (4) The Sylvian vein, as shown by the writer, is dis- tinct from and a variable complement of the medicerebral vein (vide infra). It lies at the bottom of the basi-Sylvian Jissure, covered up, except near its termination, by the tip of the temporal lobe. It arises in the region of the insula from a great number of radicies. When the medi- cerebral is poorly represented, the Sylvian may take up twigs from the surface of the temporal and frontal lobes; ‘some of the venze perforantes pass, as a rule, to this vein. There is here often a group of perforantes, separated from the others and coming from the brain substance caudad of the veins. (5) The Vene Preperforantes are small, very variable in number, and take a straight course for a short distance before splitting up. They come from the striate nuclei and adjacent frontal albalis. Their radicles approximate those of the precornual veins, yet without observable an- -astomoses. (6) The subcerebral vein receives, in its course obliquely across the optic tracts and crura cerebri, several small veinules from the chiasm, infundibulum, mammillary bodies, crura, etc. These anastomose freely with one an- other, and with those of the other side, thus making an outstretched network over these parts which connect -on the one hand with a small network before the chiasm, and on the other with that across the pons. This corre- sponds in general to what Labbé terms the inferior inter- hemispheric veins. Frequently there are accessory vein- ules from the basal temporal surface. (7) The Subcornual vein, in that it comes from the end of the middle horn, is comparable to the prechoroid artery. It is very constant in occurrence, but not in size. ‘Though connected with the choroid plexus of the medi- VOI Lea Brain, Brain, cornu, it originates in the cerebral substance, sometimes even from the lateral wall of the postcornu, oftener op- posite the caudad border of the thalamus, where branches are received from the albalis lateral to the thalamus or from other directions. In its course along the lateral wall of the horn it receives many accessions, notably from the cornu Ammonis, and as it curves around the end of the horn several twigs from the albalis of the temporal apex. (8) Postperforant, at least one considerable veinule. The post-perforating veins come, according to Hédon, from the cinerea of the walls of the diaccele, and even from the mesal surface of the thalamus. He also claims that in the striate nuclei the perforating veins anastomose with those going toward the cavities and Galen’s system. He further recognizes the communications in the medi- cornu between the choroidal and the infracornual veins. (9) Crural branches, one in particular, can be followed along the crus to the cerebellum. 5. The fine Conarial vein and variable Optic twigs often end in the supercerebellar vein instead of directly in the velar. They originate in a fine venous plexus over the optic lobes and conarium, which appears to be connected across the crura cerebri with the basal network described above. 6. The Postcornual vein is variable, complementary in derivation to the subcornual. It may arise in the albalis near the tip of the occipital lobe, and then runs subepen- dymalalong the cornual wall. The parathalamic branches above ascribed to the subcornual, and some from the Am- mon’s horn, pass often in part to the postcornual. The radiate radicles of this vein are traceable through the albalis nearly to the cortex (Fig. 820, g, q). There is frequently another vein intermediary between (7) and 6, emptying into either the subcerebral or the post- cornual, The straight portion of the velar vein in its course through the velum receives the following, all at right angles: 1. The Splenial veins (Fig. 819, f) are very small, and but two or three in number as they come out through the fornix. They often combine with thalamic radicles and empty as one trunk into the velar. 2. The Thalamo-Crural vein, usually one on each side, but sometimes multiple (Fig. 820, m, m). This begins about the cerebral crus, makes its way dorsad and mesad through the thalamus, and joins the portio recta at about its middle point. It approaches the ventral side of the velar, and hence is but too easily overseen. Neither 1 nor 2 runs any length in the velum. 3. The Thalamic veinules are very variable in size, number, and position. They may even be entirely wanting, or run to neighboring veins, e.g., the post- cornual. These arise only to a limited extent in the thalamus; they come chiefly from the albalis beyond, running across or a trifle embedded in it. Where one of these is specially large it might be termed the Z'rans- thalamic. Opposite or toward the apex of the thalamus, the velar vein is formed by the immediate or mediate union of several small trunks. Most of these are in a cluster coming in laterally between thalamus and striatum; the latter nucleus appears much richer in veins than the former. Of all but the first, the intraccelial course of these veins is subependymal. 1. The Medicornual vein (Fig. 820, 7) takes a sinuous course in the outer edge of the choroid plexus, of about double the actual distance. Its membranous envelop- ment makes it a counterpart of the pia veins, and hence the actual continuation of the velar, as held by Bell. It begins in the middle horn, where it is said to anastomose with the subcornual. It comes out of the horn with the plexus, bends to follow the lateral thalamic border, and ends in any one of the veins near the commencement of the velar. Meanwhile it receives a multitude of radicles from the plexus, and some that seem to come from the surface of the thalamus. 2. The Tenial vein comes from the thalamo-striatal 257 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Nevertheless it has few This short trunk is made Of these groove, beneath the teenia. tributaries from the thalamus. up by three sets of veinules: (a) Striatal. Fic. 820.—The Coelian Veins. there are usually two or three larger and several smaller branches, coming from the substance and surface of the caudate, and passing to the teenial trunk or to either of the following: (0) A prealbal trend of veinules, passing along the outer ccelian border toward the precornu, and thence largely to the albalis of the frontal lobe. (¢) An opposite trend, directly caudad, a short distance along the outer ccelian wall, and coming from the lenticular nucleus, the internal and external capsules, and the superimposed portion of the centrum semiovale. Many of these various albal radicles can be followed almost to the cortex; their angles of union are acute. 3. The Paraseptal trunk (Fig. 820, 0, 0). This short vessel, with its two constituent Precornual veins, is the most direct continuation of the velar. Laterally it re- ceives small Septal and Genwal accessions. There are usually two parallel precornuals (p, p). They come from the extremity of the horn and follow its contour around to the septum, or run in the adjacent border of the cau- date, though they take up no important radicles from that nucleus. Their multitude of radicles come from the albalis in the basal portion of the frontal lobe, also de- monstrable nearly to the cortex. 258 (From the author’s ‘* Veins of the Brain,” etc.) 4. The Superalbals (Fig. 820, n, ) are commonly two small trunks that appear at the outer border of the cecele,. opposite the body of the caudate, cross the latter, and empty through the teenial or para- septal trunk. They come from the ccelian roof, and the frontal and parietal albalis dorsad of those: previously described. C. Basal Veins (Fig. 821).— These do not constitute a system in the sense of having a common point of discharge—in fact, they have already been described in part under Subcerebral Vein. A1- though they are quite irregular in termination—small veins seem occasionally to end at any point in the basal sinuses—still there are: four frequent points of discharge: (1) Cavernous and (sphenoidal)- sinus; (2) superpetrosal sinus; (3) middle of lateral sinus; (4) some sinus about the foramen magnum. 1. Some small veins from the pituitary body and other struc- tures about the sella turcica have. been described as tributary to the: vene circle of Ridley. But the largest vein discharging at this. point is the Medicerebral, a super- ficial vessel following the Sylvian fissure. This should be distin- guished from the smaller though complementary Sylvian vein cours- ing at the bottom of the fissure. The medicerebral is inclined to be double, ¢.e., there are then two parallel adjacent veins, one taking up frontal branches, the other only temporal. In this case one: vein may receive some of the pre- basals above described and empty into the sphenoidal or the-cavern- ous sinus, while the other runs meso-caudad in the dura across. the temporal fossa to the middle of the superpetrosal sinus. This. latter is the course that the whole medicerebral vein takes in many cases, as Trolard rightly says; the dural portion may be termed the: Temporal Sinus; by one or two: lateral orifices it communicates. with the medidural veins which it crosses. 2. The discharge of the subcerebral vein through the vein of Gaien, as given above, holds for about one-half the cases—not always alike on the two sides. The main trunk may be diminished by the termination of some of its usual prebasal constituents in the cavernous sinus or medicerebral vein. Whether larger or smaller, the trunk as often passes to a basal sinus (superpetrosal) by turn- ing ventrad instead of dorsad on reaching the cerebral crus. One or more Precerebellar Veins from the flocculus region (Floceular Vein) pass to the superpetrosal sinus, with the subcerebral vein, when this terminates at the base; other- wise they seem to connect with this by veinules along the lateral surface of the cerebral crus. Among the cerebellar veins Hédon, referring to Merkel, mentions. one that “comes from the flocculus and empties into the superpetrosal sinus. An important branch of this vein rises from the interior of the cerebellum in the region of the dentatum, receives also veins from the cerebellar medipeduncle, and emerges with the peduncle under the flocculus. The main trunk can acquire a very con- siderable size when it receives a branch of the basilar vein” (precerebellar vein, Fig. 821). REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, 3. The Postcerebral Veins (Fig. 821, MW) usually unite into one trunk just at the point where, turning caudad, they form an ampulla in the dura and enter the sinus. This is at the lateral border of the occipital lobe, opposite the exoccipital fissure. These veins come in part from the convexity, in part from the basal surface of the occipital lobe. The latter may be single or multiple; their deriva- tive area is lateral to that of the suboccipital vein. The former is represented by one large trunk from the direc- tion of the Sylvian fissure; it receives varying temporal branches and larger ones from the external occipital sur- face. The Paracerebellar Veins are smaller than the post- cerebrals, but often empty opposite them, though, of course, subtentorialin origin. They come from the lateral portion of the cerebellum. The very inconstant Postcere- bellar Veins, one or more in number, terminate in the lateral sinus near the torcular, or even in the tentorial. 4. The Subcerebellar Veins include any small vessels at the bottom of the posterior fossa discharging into the occipital sinus. The cerebellar veins,—supra-, pre-, para-, post-, and sub-,—are but partially distinct from the cerebral veins. Oblongata Region.—The ventro-mesal chain of myelic veins (see Fig. 821, 0 ) is continued cephalad on the ven- tral surface of the oblongata to the furrow between this and the pons, there connecting with a fine venous net- work over the surface of the latter (Kadyi). This plexus in turn also connects with the veins of the cere- bellum and of the base forward. Besides irregular smaller ones, there are in particular two constant and considerable veins passing from this plexus, one on either side along the trigeminal nerve to the sinus petrosus (or cavernosus). From the above-mentioned chain on the ventral surface of the oblon- gata, between the pyramids, there frequently arises a little trunk (up to 0.5 mm. or more thick) that joins one of the hypoglossal root bundles and passes out with it through the precondyloid foramen—doubtless a part of Luschka’s plexus venosus hypoglossi. The dorso-myelic chain of veins is continued cephalad over the ob- longata. From a constant mesal vein here a small veinule traverses the arachnoid, covering the cisterna magna. Sometimes this adjoins the accessory nerve, and Kadyi thinks it probably empties into the sinus plexus about the foramen magnum. GENERAL FEATURES OF THE IN- TRINSIC VELNS. — Communications. —In this regard the pia veins must be distinguished from those of the brain substance. In contrast to the arteries, the pia veins communicate freely, not only indirectly through the sinuses, but everywhere on the surface by a network of small ves- sels, as well as frequently by anas- tomoses between larger trunks. The veins of the convexity might almost be said to radiate from the Sylvian fissure (horizontal Sylvian). At least several of the larger ones connect toward the middle of the convexity. Of these, four may be specified: (1) One of the frontal supercerebrals (fronto-dorsad); (2) the second or third from the last su- percerebral (caudo-dorsad); (8) the external trunk of the postcerebral (caudo-ventrad); 4, the medicere- Kadyi. common arrangements of these veins. A, A, Supracerebrals ; B, ramus to olfactory bulb ; C, C, subfrontals ; D, precerebral ;: E, E, Sylvian or insular; F, medicerebral (to cayernous sinus); F’, postmedicerebral (per temporal sinus to superpetrosal) ; G, G, preperforantes ; H. postperforantes ; I, subcerebral (to Galen’s vein); I’, subcerebral (when emptying at base); J, J, subeornuals; K, K, precere- bellars and flocculars; L, L, hypoglossals (to precondyloid emissary) ; M, postcerebral (to, lateral sinus) ; N, paracerebellar (to lateral sinus) ; O, ventromyelic (anterior spinal). bral (fronto-ventrad). Or any two of these trunks may communicate independently, e.g., the medi- and post- cerebral veins by a large anastomosis directly across the temporal lobe (intrapial, of course), There are many other connecting veins, not as markedly bridging the fissures, however. The great anastomotic vein of Tro- lard is No. (4) (medicerebral) when continuous with No. (2). Labbé’s illustration includes also No. (8). Trolard - says it “sometimes takes origin at the side of the longi- tudinal sinus, but oftener it forms by the union of veins anastomosing at the middle part of the convexity.” He encountered it twenty-five times in thirty subjects. Ac- cording to Labbé this anastomosis, instead of being with the medicerebral, may, in its absence, be with the deeper Sylvian vein. Practically these various anastomoses present a collateral path in the pia, between longitudinal, lateral, and cavernous (sphenoidal or superpetrosal) si- nuses. The basal veins, excepting the perforants and the cerebellars, have ample though smaller anastomoses, including an indifferent counterpart of the circle of Willis. It is evident that the derivative area of the pia veins can never be closely defined. The internal system must be separated into those veins uniting in the curved portion of the velar, and those tributary to tne straight portion. The former, as the writer has elsewhere shown, have the following sets of Fig. 821.—Veins of the Base (34 natural size). The two sides represent respectively the more Those of the myel and oblongata are largely after 259) Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. anastomoses: (1) Between the callosal vein—including practically the rare interhemispheric vein—and the me- dian branches of the supercerebrals, across the callosal fissure; (2) between the suboccipital vein and the basal branches of the postcerebral; (3) between the supercere- bellar and other cerebellar veins; (4) between the subcere- bral vein—when, as in about one-half the cases, this dis- charges into the velar—and the many veins adjacent to its derivative area. These communications are all in the pia; from clinical cases we know that these may suffice to compensate fairly when only the tentorial sinus and the short common vein of Galen are closed. They do not suffice, however, when there is any impediment to this collateral discharge, and possibly not when the sub- cerebral vein ends elsewhere. Of the veins passing to the portio recta of the velar vein, only one, the medi- cornual, has superficial anastomoses. As this is a long, tortuous vessel, and connects with the subcornual only by small and questionable anastomoses, it is of itself entirely unable to compensate when the portio curvata becomes occluded. We have, remaining, the various ceelian veins coming directly from the brain substance, to which the postcornual may also be added. Neither between these nor between their subdivisions short of the ultimate capillaries did the writer succeed in finding any anastomoses. The same holds true for the perforat- ing veins of the base. There still might be intrasub- stantial connections between these vessels and the cortical veinules. However, the apparently positive results of injections by Duret, and especially by Labbé, are all ex- plicable by the surface anastomoses above described. There may be such occasional but inadequate connections paralleled by the rare ones between the otherwise terminal perforating and ccelian arterioles. Hédon (1888) says that a few do exist. Clinical evidence also goes to show that the veins emanating from the ccelial walls are all essentially terminal vessels, and that closure of the velar vein—unless just at its mouth—cannot be compensated. Cortical Veinules.—Duret found only six or eight in the section of a medium-sized convolution, one or two emanating perpendicularly at the dorsum of the gyrus, and from four to six by the sides. However, they had a diameter triple that of the arterioles. They start principally from the capillary transition plexus—between gray and white—and from the deeper albalis. Developmental.—From various peculiarities in the vas- cular supply of the human brain, more especially the caudad displacement peripherally of the postsupracere- bral veins, the writer has adduced evidence favorable in a general way to Hill’s theory of a developmental rota- tion of the brain, and showing further that in any such rotation the brain and pia have glided caudad under the dura and brain case. Here may be added a casual observation of a persistent fetal form, made at the autopsy of a child of twenty- two months, dead of tubercular meningitis. The large left medicerebral vein took the temporal course in a deep groove (per temporal sinus, intradural), and passed out at the foramen jugulare spurium instead of passing to the suprapetrosal sinus, first, however, connecting with a much smaller prepetrosal sinus. No such appearance on the right. GENERAL RELATIONS OF THE VEINS AND ARTERIES. —In the pia, over the convexity and on the median sur- face, the arteries lie beneath the veins (Labbé), as gen- erally in the body elsewhere. But over the insula, and evidently in the sulci generally, the writer has observed the reverse; while of the finer pial arborizations Labbé asserts that the venous lie beneath the arterial. Though the larger veins often jump across from one gyrus to the next, the a_tcries go down with the pia more or less deeply in*< « -e fissures, to come up near or distant over the next gyius. Only by a forced comparison can any of these veins be said to accompany the arteries. By contrast, the dural vessels conform in their general bearing to those else- where; they have abundant collateral anastomoses, most of the arterial branches are accompanied by two veins, etc. 260 Dwight quotes the suggestion that, as the blood in the internal jugular and carotid flows in opposite directions, the arterial pulsations might interfere with the venous discharge, if both lay ina common canal. Trolard drew a strong analogy between the vertebral artery, surrounded by the vertebral vein and plexus, and the carotid through the cavernous sinus. “The supply arteries of the en- cephalon bathe (?) in venous blood; the carotids from the moment they enter the carotid canal; the vertebrals from the moment they penetrate the vertebral canal.” This point has been elaborated by Riidinger (vzde abstract in Boston Medical and Surgical Journal, 1888, ii., 3238). He shows that by this cushioning the pulsatory move- ments of the arteries are not abolished as they would be if they filled the bony canals. The diameter of the carotid canal he gives as 5-7 mm.; that of the artery, 3-4.3 mm. In the cavernous sinus the artery, though situated at one side of the cavity, is not in contact with either the bone or the dura. The various retarding bends and angles in both classes of vessels can only be referred to. They affect very un- equally the circulation in the different parts. The exist- ence in the pia of vessels larger than capillaries, connect- ing the arteries with the veins, has been many times asserted and denied—the last investigator, Labbé, con- triving todo both. This point still awaits final settlement. Ill. Tue Dura Srnuses.—The encranial sinuses are all intradural, and all except the tentorial (with the fal- cial) lie against the cranial wall. They do not collapse on being slit open, nor do they admit of much distention —the falcial and the parasinual spaces excepted. They are lined by a continuation of the inner membrane of the jugular. Allen counts 16 sinuses—10 paired (sym- metrical), and 6 unpaired (azygous). But their number depends so much on the way they are divided as to cause the remark that the easiest piece of anatomical work was to describe a new sinus. They have been variously classified: (#) In two re- ciprocally perpendicular planes, the vertical plane in- cluding the longitudinal and tentorial (plus falcial), the horizontal including the remaining; or (4) in three hori- zontal planes; or (¢c) as connecting at three points, viz., the torcular and the two cavernous sinuses (to which Trolard sought to add a precondyloid confluens); or (@) according to the area drained. The Longitudinal Sinus.—This, the longest sinus, runs parallel to the sagittal suture, slightly grooving the bone in a curved line from near the crista galli to the internal occipital protuberance. It lies between the folds of the falx, as they diverge to continue as the parietal dura. Its section presents a rounded triangle, increasing in size from the accession of large veins. Its lumen toward the bottom is crossed by numerous irregular strands (trabec- ulee, chordee Willisii). The openings from the supercere- bral veins are usually larger than those from the para- sinual spaces (and dural veins). The sini subalterni of Malacarne are often seen in the falx just beneath the sinus, and present more or less developed parallel narrow passages freely connecting with the main vessel. At the torcular this sinus more often turns into the right lateral. Rarely it, or its tributaries, drops down through the falx to the falcial sinus, or just before the torcular to the tentorial, or even divides, following the lambda sutures to each lateral sinus. The whole longitudinal sinus may be occluded without causing disastrous results. Faleial Sinus.—This may run along about two-thirds of the free border of the falx or near the border, and then represents the continuation of the tentorial sinus. It is rather a large dural vein than a sinus. At its commence- ment the occasional interhemispheric veins empty. Its only lateral tributaries are usually small dural veinules, though part of the supercerebral veins or of the longi- tudinal sinus have in rare instances been seen to turn this way. On the contrary, Knott once saw the falcial pass to the longitudinal, and some connection between. the two is not uncommon. But, as stated by Luschka, this sinus is very variable in size and occurrence. In a series of adult subjects the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, writer found that its average occurrence was only one in six; in the foetus it was never present. Trolard’s at- tempt at presenting this as an important anastomosis between the dorsal and internal systems, or as a safety diverticle of the latter, was quite overdrawn. Tentorial Sinus,—This lies at the junction of the falx and tentorium (Figs. 819 and 820, a). It extends in full size from the torcular to the intersectiom of the free falcial and tentorial borders opposite the point where it receives its main tributary, the vein of Galen. Its sec- tion is a triangle with narrow base resting on the ten- torium. Laterally it takes up small dural radicles, and often a supercerebellar vein. It is straight, lies in the median line, and is directed caudad. “It opens into the lateral sinus by an oval mouth formed by strong pillars of fibres.” Torticular.—A. confluens sinwum in the sense of the old writers does not exist. “The right lateral sinus for the most part begins higher than the left, and may be con- sidered as the continuation of the longitudinal. In some subjects the right or left lateral sinus begins from the longitudinal one, while that of the other side is continu- ous from the tentorial; and then the lateral sinuses are separated at their origin by a membravous isthmus” (Charles Bell, 1827). Riidinger speaks of a “valvular arrangement” separating the two currents. In 26 out of Knott's 44 cases, the tentorial opened into the left lateral sinus, in 6 into the right, in 12 mesially. The statistics given below, on the larger jugular canal, bear on this question. This peculiarity of the paths at the torcular tends to prevent a reflux of blood from one into the other, or any interference of the currents. However, in a considerable minority of cases the cur- rents must intermingle. From the arrangements of the sinuses at the torcular, thrombosis of the longitudinal and right lateral is more often associated than of the longitudinal and left. A comparison of the few casual cases at hand shows 6 of the former to 2 (or possibly 8) of the latter. Of course, much more frequently—in 12— all three sinuses were involved. Lateral Sinus.—This runs from the torcular, at first in the attached tentorial border, then curves (jflezura sigq- motdea) to follow the groove in the mastoid and gains the jugular canal. It has been seen to take a more basal course, running: first in the cerebellar falx, then beside the foramen magnum to its usual exit. From the exten- sive investigations of Hartmann, Riidinger, Bezold, and Politzer, it appears that frequently the sigmoid portion approaches within a few millimetres of the posterior wall of the auditory meatus. The one into which the longitudinal sinus turns, usually the right, is double the size of the other, and also a trifle longer. Rarely, one lateral is minimal in size or even absent. It receives laterally the postcerebral and paracerebellar veins and superpetrosal sinus, and gives off two inconstant emis- saries. Korner (1889) has shown that intracranial disease from caries of the petrous is more frequent on the right, and from a study of 449 skulls he attributes this to the fact that the lateral sinus at its sigmoid flexure enters deeper into the mastoid and the petrous pyramid on the right than on the left, and thus on the right approaches nearer the primary focus of disease. In 22 cases on the right and 8 on the left, there were gaps in the bony partition. He also holds that in the brachycephali the sigmoid ex- cavation goes lower and deeper than in the dolichocephali, and that hence in the former such encranial sequele fol- low more readily ; but this has been disputed by Schiilzke. Birmingham, of Dublin (Brit. Med. Journ., 1890, ii., 683), from an examination of 100 recent dry specimens, points out that the relations of the lateral sinus to the surface are extremely uncertain, owing both to variations in the sinus curves and to irregularities in the bones. It begins opposite the external occipital protuberance in 50 per cent.; lower (by never more than one-half inch) in 83 per cent.; and higher in 17 per cent. It does not run forward horizontally, but is distinctly arched. The bend of the sinus where it turns down at the asterion may vary, within wide limits, from a gentle to a very sharp curve. It then runs down in front of the post- mastoid margin, about one-half inch behind the meatus, and turns into the jugular foramen about one-quarter inch below the level of the meatus floor. Occasion- ally the sinus is only one-twelfth of an inch from the surface. Cavernous Sinus (Plate XVIII., Fig. 1), distinguished by its irregular outline and cellular or reticulated ap- pearance from intercrossing fibrous bands. It represents a colossal perivascular structure about the carotid, in a way similar to that established by Braune and his school for certain lymphatics accompanying veins. The late von Langer, in one of his last publications, based on cor- rosion and other preparations from infantile subjects, showed that the cavernous sinus is originally a plexiform network of veins, which, by fusion of its channels, takes on its later characteristics. The wall resorption goes on to old age, when villous offshoots of the remaining tra- becule are often seen to project into its cavity. It is traversed by the carotid (cavernous portion). All the orbital nerves except the optic pass near or through its outer wall. Besides veins and emissaries, it is the com- municating centre for all the prebasal sinuses. Frontad it tapers to the ophthalmic vein—the swollen end of which has been dubbed Sinus Ophthalmicus. Laterally, the cavernous receives the Sphenoidal Sinus. This runs out along the dependent side of the lesser sphenoidal wing. Knott notes great variability in its size, though never complete absence, a small vein at least being found. Peripherally it receives or connects with a medidural vein, and also a diploic canal, and may take up the medicerebral and connect with ophthalmodural veins. The Subsphenoidal Sinus, on the great wing of the bone, was found by Knott fourteen times on the right and nine on the left side. Mesad, the cavernosi connect by the two Transverse Sinuses—which alone deserve to be called transverse. These follow the walls of the sella turcica, curve slightly to enclose the pituitary body, and complete the so-called vene-circle of Ridley (Plate XVIII., Fig. 1). Sinus Prepetrosus (jugularis spurius of Luschka, petroso-squamosus of Hyrtl, petrosus anterior of Bell). This occasional sinus, at the bottom of the temporal fossa, describes a curve along the petro-squamous suture, from the spinous foramen—connecting with the medidural vein and also with the cavernous sinus—to either (or both) the emissarium temporale or the petrous portion of the lateral sinus (often by perforating the prominent petrous ridge). Its physiological interest arises from the prominent part which it plays in the foetus. Zuck- erkandl (1878) found this sinus 22 times in 280 skulls. Knott, 4 times in 44, found what appears to have been a continuation of this sinus to the sphenoidal; in 7 of 44 subjects he found the prepetrosal on both sides, in 19 on one side only. Caudad, the cavernous empties into the oblique su- per- and sub-petrosal sinuses, but principally the former. The Superpetrosal Sinus starts from the cavernous, runs in the prolonged attached border of the tentorium along the dorsal ridge of the petrous bone, and enters the lateral sinus against the current at the beginning of its sigmoid flexure. It alone offers a direct encranial connection be- tween the prebasal and lateral sinuses. The temporal sinus (medicerebral or anastomotic vein) and the subcer- ebral vein discharge into this in nearly one-half the cases, the precerebellar vein more constantly. As a con- sequence, its size varies considerably, though it is usu- ally small. The vestibular and even tympanic veins of the ear pass to the superpetrosal sinus, either directly or by a dural vein. In his forty-four subjects, Knott notes its absence twice on the right and once on the left. The shorter Subpetrosal Sinus runs in the petro-occipital groove, from the cavernous sinus to the subpetrosal vein, which, by bending before its discharge into the jugular vein, secures an unimpeded outlet for this sinus (for con- nections, vide infra, Vena Subpetrosa). 261 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Occipito-Basilar Plexus.—In the occipital fossa are sev- eral sinus canals that vary much in size and distribution. The Occipital Sinus, usually bilateral, runs along the cere- bellar falx and connects with the lateral sinuses by small mouths beside the torcular. Pre-, trans-, and post- occipitals have been made out. The so-called circular sinus of the foramen magnum is more often incomplete dorsad of the hole. The basilar sinuses over the like- named process connect with the preceding and with the prebasal sinuses. Langer has shown that, like the cav- ernous sinus, all of these are the persistent channels of what originally, in the foetus, was a vein plexus; and he has also corroborated Virchow’s description of their en- largement in the aged. Parasinual Spaces.—These areolar venous pockets or derivative reservoirs (lacunte, recessus lateralis), though described with increasing definiteness by a long series of observers, find but little mention .in the text-books. Their principal development is opposite the middle of the longitudinal sinus (bilateral). As numerous minute spaces they further occur along nearly the whole length of the said sinus, and also (Langer) beneath it in the falx, beside the lateral sinuses, on both sides of the tentorial sinus, and it is said even about the cavernosi. The di- lated intradural termination of the postcerebral and para- cerebellar veins has also been thus classed. They all occupy the attenuated space between the dural layers lateral to the sinuses, and hence are very shallow and of irregular outline. They have a lining membrane, also many intercrossing fibrous filaments, and are injectable from or with the sinuses. In positionand characteristics they are intermediary between dural veins and sinuses. Where present they receive most if not all the dural veins. The larger spaces are traversed by incoming pia veins with which they connect by one or more openings. They increase in size as life advances, and then have in- timate relations with the Pacchionian granulations—so much so that they have even been termed Pacchionian blood cavities. The circulation in their interior is not believed to be very active and the spaces have repeatedly been found thrombosed. On opening a sinus or the jugular canal blood usually flows out inamore or less pulsatory stream showing that the ruling interior pressure is positive. In the cases of operative perforation of a lateral sinus (Jacoby, Knapp, Benton, Guye, Owen, Reeve, von Baracz, and others, usually ending in recovery) there is no record of air being aspirated. But in one case of opening of the longitudinal (Genzmer, 1877) so much air was aspirated as to prove quickly fatal, and Francois-Franck (1881) has endeavored by experiments to show that aspiration can be communicated through the vertebral veins to the diploic canals of the occiput. Occlusion.—Blocking of any single sinus is not neces- sarily dangerous, though occlusion of a cavernous or the tentorial is always a serious matter. By experimental blocking of the dural sinuses in the dog, Ferrari (1888) has shown that a large part of the whole sinus system, e.g., all the sinuses of the calvarium, may be rendered impermeable without injury to the functions of the brain. However, occlusion of the col- lective blood efferents from the skull is of course quickly fatal, being usually preceded by an epileptic attack. But all this and more had been already determined by clinical experience in man. IV. VENovus OPENINGS THROUGH THE SKULL (EMts- ‘SARITA, ETC.).—From their number and pathological im- portance, and for clearness of description, these passages ought to constitute a separate class. Each of the cranial bones (except the ethmoid) has a foramen permitting direct communication between the dural sinuses and veins and the exterior veins; still these are of very unequal size, and in part disappear in the adult. There is but little topographical correspondence between the position of these exits and the area drained through them; nor is the area in any case closely definable. They may all act as efferent vessels although the ophthalmic veins are usually afferent—partially so, says Sesemann, 1869; 262 largely so, Gurwitsch, 1883, and Merkel—and certain of the others may conduct either way according to circum- stances. Only Nos. 2, 6, 7, and 8 are superficial, while 7, 8, 11, and perhaps 4, belong rather to the dural and diploic system. Nearly all the blood normally passes out through the two postlacerated foramina with their four canals. But any one of the exits and, so far as known, any two—or, in case of the smaller emissaria, several—may be permanently closed without causing serious harm. Both internal jugulars have been tied in the same subject (Pilger, 1880) without other evil con- sequences than a temporary headache. 1. Jugular Canal.—In the lateral part of the postlac- erated foramen. This, by far the largest of all the exits, leads from the sigmoid flexure of the lateral sinus to the bulb or gulf of the internal jugular vein. Its path through the foramen is often more or less separated from the passing nerves, etc., by @ bony septum, thus forming a true jugular foramen. Rarely it is very small on one side, or even absent (four or five known cases). By adding the series of 159 skullsexamined by Dwight to the 100 by Riidinger, we have 259. In 1738 of these the right jugular foramen was larger than the left (7.e., about two-thirds), in 65 the reverse (one-quarter), and in 21 the two were equal (one-twelfth). This harmonizes with what was said above (swb Torcular). 2. Emissarium Mastoidewm, of most importance in fetal life. It arises directly from the lateral sinus, and empties usually into the occipital vein (extracranial), sometimes into the postauricular, or even directly into the external jugular. In the 16 perfect skulls ex- amined by Green (American Journal of Otology, vol. iii.), it was absent on both sides in 1, and on one side in 1. It was always just behind the posterior limit of the mastoid process. The external opening was opposite the meatus (at about the middle of the perpendicular height of the mastoid) in 20, above this in 2, below in 6, and directly on the base of the skull in 1. Its diameter measured 5 mm. in 1, 4mm. in 4, 3 mm. in 10, 2 mm. in 10, and 0.5 mm. in 4, 3. Emissarium Postcondyloideum (postjugular vein), passing from the lateral sinus near its termination to the upper cervical or vertebral veins. In 44 skulls, Knott found this on both sides in cnly 138, on the right in 21, and on the left in 10. In Dwight’s series of 142 skulls, with unequal jugular foramina, the postcondyloid fora- men was larger on the same side as the larger jugular in 58, on the other side in 37, and equal or absent in 52 (this foramen being wholly for the transit of the emissary). 4. Emissarium Precondyloideum, connecting with the occipital sinus or its basal prolongation, taking up a diploic vein, and passing in part to the prepetrosal vein, in part to the plexus about the vertebral. As plexus venosus hypoglossi, Luschka described a cluster of veins about the hypoglossal bundles as they unite in the inner portion of the foramen, from which two veins passed down the canal. Trolard says that externally the pre- condyloid foramen presents a deep cavity in which is lodged a true venous confluens. Ventrad its wall is hid- den by the external part of the atlo-occipital ligament. He says that this confluens receives five veins: (1) Ven. trad and mesad, the medilacerate; (2) latero-ventrad, a connection with the subpetrosal vein; (8) dorsad, a pre- condyloid vein; (4) latero-dorsad, an inconstant vertebral vein (passing between atlas and occiput, behind the in- ternal jugular, sometimes in a bony canal); (5) a little vein on the preatlo-occipital ligament, communicating across with the intraspinal sinuses. Dwight, in the same series of 142 skulls, found the precondyloid foramen larger on the same side as the jugular in 16, on the other side in 11, the two sides equal in 115. “There does not appear to be any definite rela- tion between their size and that of the postcondyloids.” 5. Small uncertain veins through the foramen magnum or beside the vertebral arteries, connecting some mar- ginal sinus or vein with the vertebral and spinal vessels. The fine veins in the spinal cord also connect with intra- substantial ones above. EXPLANATION OF PLATE XVIIL | | | EXPLANATION OF PLATE A VALI: Fie. 1.—Sinus Cavernosi et Intercavernosi—Sinus Circularis of Ridley. Inferior aspect of a corrosion preparation from a child, with afferents and efferents (some- what enlarged, and also arbitrary as to execution of smaller vessels). From Langer’s “ Der Sinus cavernosus der harten Hirnhaut,” Sitzbr. d. k. Akad., 1885, Vienna (Fig. 5). V.o., Vena ophthalmica superior et inferior. S.z.c., Sinus intercavernosi. ; #, Emissary veins passing through the oval foramen to the pterygoid plexus. S.p.z., Sinus petrosus inferior. L, Space for the dorsum ephippii. Fig. 2.—Fine anastomotic network between three arterial twigs in the pia of the parietal region. (Lucas, Paris Thesis, 1879.) Fig. 3.—Lobule of a choroidal villus; one portion bare of epithelium. Sinuous vascular loop. En- largement, 500 diameters. (From Luschka.) a, Portion covered by epithelium. b, Fibrillary connective tissue. c, Structureless connecting substance extending well beyond the capillaries. Fic. 4.—Very perfectly injected vessels of a choroidal villus. Two hilus vessels, a vein, and an artery. Loops, vascular nets, etc. Enlargement, 50 diameters. (From Luschka’s “ Die Ader- geflechte des menschlichen Gehirns,” 1855, Taf. ii., Fig. 2.) ae Dees OF THE Rererence HanpBook MEDICAL SCIENCES. oa Brain-Vessels (Vide Explanation at End of Article). LIBRARY OF THE UNIVERSITY of ILLINOIS. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain. 6. Hmissarium Occipitale, a small mesal conduit from the torcular through the occipital protuberance to the external veins of the occiput. It is often, but not always sinuous, and takes up an azygoid diploic trunk. Knott found it as a small but traceable vein in 6 of his 44 cases. In most of the others there was a small vein piercing one of the bone plates and anastomosing with the diploé veins. 7. Hmissarium Parietale.—In 100 skulls Gruber found the parietal foramen on both sides in 29, on the right in 19, on the left in 12; average distance from angle of oc- cipital squama, 3-5 cm.; distance from sagittal suture, 2-17mm. Their size varies ordinarily from 4 to 1 mm. They do not terminate internally directly in the long ‘sinus, but in the parasinual spaces or dural veins. 8. Diploie Connections.—Innumerable small openings through the inner plate of the skull connect the dural veins and spaces with the diploé canals. These are largest and most numerous along the longitudinal sinus (corrosion preparation). 9. Orbital Connections.—(a) The ophthalmic vein is, next to the jugular, the largest and most constant of all the passages. It empties largely into the cavernous sinus (through the orbital fissure, where it bears a constant constriction), but has free anastomosis with the prefacial vein at the inner canthus. Allen says that formerly the trunk of the facial was opened at this point to relieve cerebral congestion. (0) The central retinal vein has full anastomoses with the ophthalmic, but goes as arule to the cavernous sinus, or frequently to a fine venous plexus around the optic nerve, and then by several veinules in part to the subophthalmic vein, in part to the said sinus. (c) The smaller subophthalmic vein or veins connect doubly with the larger into which, or oftener into the sinus cavernosus, they discharge (always afferent, say Sesemannand H. Meyer). Peripherally, they anastomose with facial and even pterygoid veins. (d) The oph- thalmo-dural vein of Hyrtl] (1859) is practically included under the more or less constant connection of the medi- cerebral vein and the sphenoid sinus. Occasionally this sinus or vein has a small anastomosis, through the lateral part of the orbital foramen, with the ophthalmic or other orbital vein. Evidently, the vena aberrans of Verga (1856) should be classed here. As a passage from the ophthalmic vein or cavernous sinus to the lateral sinus, Knott mentions one case (on right); or between ophthal- mic vein and superpetrosal sinus, three instances (on left). 10. The Hinissary of the Foramen Rotundum from the cavernous sinus, and accompanying the superior maxil- lary nerve as described by Nuhn, was twice seen by Knott (on right). 11. The medidural vein discharges largely through the oval, or spinous, foramen. Nubn described a pair of veins which, after traversing the oval foramen, formed a plexus about the inferior maxillary nerve and terminated in the infratemporal veins. Knott found these veins on both sides in 18; two veins on right and one on left in 6, the reverse in 4; a single vein on each side in 11; no vein on one side in 5. Luschka and Trolard describe a vein, from the cavernous sinus, that receives dural veins from the anterior petrous surface and departs through the oval foramen; in this case the medidural emerges through the spinous foramen. 12. Plexus s. Sinus Caroticus.—Bell (1827) mentions a vena sodalis arteria carotidis, as an emissary from a petrous sinus, descending through the carotid canal. Rektorzik (1858) seems to have rediscovered this. A prolongation of the cavernous sinus into the carotid canal constitutes the sinus caroticus. This breaks up into a plexus of small veins about the artery, converging to one or more small trunks below, that may pass to the internal jugular. It may connect with 11 and 18. Knott was always able to find this communication, though the vessels varied much in size and number. 13. Vena Medilacerata.—Englisch is credited with having described (1863) a constant communication, out- side the skull, between the cavernous sinus and the sub- petrosal vein. As inferior petro-occipital sinus, Trolard independently described the same. “On the exterior base of the cranium a small vein occupies a groove ex- tending between the two lacerated foramina. Its direc- tion is latero-caudad. Itinosculates with cavernous sinus or carotid plexus, and with the precondyloid confluens ” (vide supra, sub 4).. Knott found this in 14 out of 33 cases. 14. Vena Subpetrosa, from the subpetrosal sinus, through the premedian portion of the foramen postlacerum, to the jugular vein. Here it is separated—not rarely by bony lamina, thus forming the foramen anomalum of Gruber, 1869—by three nerve trunks from the jugular canal. From numerous investigations Gruber found that only rarely did this vein pass quite through the foramen before entering the jugular, and that then it first con- nected with the termination of the lateral sinus. How- ever, in 8 out of 22 times Knott found that the vena sub- petrosa ended at about the level of the lower margin of the jugular foramen, in 9 a little above, and in 5 a little below. It connects also with the precondyloid vein or confluens, and commonly receives the internal auditory veins. To these may be added the following, of rare occur- rence in the adult: 15. Emissarium Temporale (foramen jugulare spurium). This is held to be a relic of the primary jugular vein. When present, it proceeds from the prepetrosal sinus, perforates the temporal bone beneath the root of the zygomatic arch, emerges just behind the glenoid fossa at the edge of the porus acusticus externus, and ends in the external jugular system. 16. Horamen Caecum, in fetal life a communication be- tween the longitudinal sinus and the veins of the frontal sinus, ethmoid bone, and nose. Rarely, if ever, observed in the adult. 17. The very rare pathological venous blood tumors of the cranium (vide Mastin, Jowrnal of the American Medical Association, 1886), arterio-venous aneurisms of the scalp, etc., occasionally communicate on the one hand with ex- ternal veins of the head, on the other through openings in the bone usually with the long sinus. 18. Possibly a couple should be added from Hédon. Small rami accompany the olfactory bundles through the cribriform plate of the ethmoid, of course connecting above with the vein of the olfactory bulb. “A vein leaves the aqueduct of Fallopius by the stylomastoid foramen to anastomose with the external jugular or post-auricu- lar (Sperino). It joins, according to Blandin, a small dural ramus traversing the hiatus of Fallopius.” LyMPHATIC SYSTEM IN THE Brain.—There are no lymphatic glands in the cranial cavity ; nor does the brain possess a system of independent lymphatics. Within the brain substance all the larger lymph passages accom- pany the blood-vessels as cylindrical enveloping spaces. These are at least twofold: (a@) Adventitial spaces between media and adventitia, which latter are not closely bound together in the vessels of the central nervous system as in the remainder of the body: (0) perivascular spaces of His and Robin, connecting with the subpial or so-called epicerebral space. Their cxistence in normal tissues has been repeatedly disputed, and unquestionably their size is artificially much increased by the usual methods of preparation. The latest investigators, Rossbach and Sehrwald, assert very positively the real existence of these spaces. They worked by Golgi’s method, claiming that this marks the lymph, and thus the lymph spaces, rather than the ganglion cell and its processes. The beginning of the lymph passages is to be sought in the very narrow spaces surrounding the ganglion cells —pericellular spaces (Obersteiner). To each of these latter spaces run, according to Rossbach and Sehrwald, many fine canals (rootlets), often coming a long distance through the albalis, and starting about vessels and from glial lymph spaces. These surround the protoplasmic cell processes. The efferents from these cell spaces pass along the apex process, branch, and empty into perivascular and superficial glial spaces, or directly into the epicere- 263 Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. bral space. The lymph system of each ganglion cell has no direct anastomoses with that about any other such cell. They also describe a lymphatic plexus about the glia cells (periglial space), especially in the external cortical layer, and in the first subcortical albalis. These are often intermediary between the pericellular spaces and the perivascular spaces, into which latter and the epicerebral space they empty. The results of Rossbach and Sehrwald, regarding lymphatics in the brain substance, are evidently dis- credited by Frommann (Centbl. f. med. Wiss., 1888, pp. 881, 882). As regards the hypophysis, Pisenti and Viola (zbid., 1890, pp. 451, 452) believe that certain structures observed by them represent lymph spaces. A. cortical lymph-connective system has been studied by Bevan Lewis. The lymphatics of the choroid plexus in the paraccele unite (Arnold) to one trunk following Galen’s vein. In the ependyma lymphatic networks have occasionally been observed. The lymph passages collect in the pia to larger trunks, follow the course of the veins, and pass out, in part through the jugular foramen to superjugular glands, in part through the carotid canal to the deep cervical glands, in part beside the vertebral vessels to the infrajugular glands. Little evidence of lymphatics in the myel is found by Kadyi. The perivascular spaces of His occur, but are likely of artificial origin. From the results of one injec- tion he figures a network of voluminous canals running longitudinally beside the central canal, and that possibly represent a lymphatic system. SeRovus CAVITIES, CEREBRO-SPINAL FLUID, ETC.—Be- tween dura and arachnoidea is the subdural space. In the normal condition this contains only a capillary layer of fluid. The dura has a system of lymphatics accom- panying the blood capillaries, within their adventitia. Besides, in the endothelium of the dura independent lym- phatic plexi and stomata have been described, presenting a communication with the subdural space, and conduct- ing off the subdural fluid. Through the oval and spinous foramina pass (Arnold) lymphatics to the deep facial glands, probably coming from the dura. The interstices of the pia, ¢.e., the somewhat broken room between arachnoid and pia proper, constitute the subarachnoidal space (cavum subarachnoidale). This is the retainer of the cerebro-spinal (cephalo-rachidian) fluid. Although this fluid can pass back and forth between the corresponding cephalic and spinal spaces, it is no longer held that there is a continuous ebb and flow from one to the other at each respiratory movement and even pulsa- tion. This space is exceedingly attenuated wherever the brain lies close to the skull, as over the convexity. At other points it forms lacuna-like pockets, termed by Key and Retzius cisterne. Among these may be mentioned: Cisterna magna (cerebello-oblongata), where the arachnoid spreads across from the caudad border of the cerebellum to the oblongata; cisterne frontis (laterales et media) ; cisterna Sylwii; and over the optic lobes the cisterna ambiens. The celes connect with these cavities (the ceelian fluid comes from the choroid plexuses—vide Plate XVIIL., Figs. 3 and 4); the metepiccele with the cisterna magna through the foramen Magendii and the aper- ture laterales; the paraccele with the diaccele per the foramen of Munro; and the diaceele with the metepiccele through the aqueduct. There is no canalis Bichati, for- merly supposed to connect the paraccele with the sub- dural space. Hence, while the ccelian and subarachnoid cavities are united, neither has any direct connection with the subdural space. An indirect connection may be offered by the nasal lymph net, as this may be injected from the subdural as well as subarachnoidal space, by way of perineural lymph passages about outgoing nerves. Another assumed indirect connection is by Pacchionian bodies and the sinuses. The experiments of Key and Retzius, confirmed by Kollmann (1880), seemed to show that the perforations of the dura—opposite venous spaces —by these bodies furnish one of the principal discharge 264 paths for both-subarachnoidal and subdural spaces. Probably, however, their injections produced artificial openings, not existing intra vitam. Certainly they do not usually attain any development until long after youth has passed. Further reasons in opposition are given by Adamkiewicz in his polemic (Eulenburg’s “ Real-Ency- clopidie,” 1886, art. “Gehirndruck”) against Bergmann’s theory of brain compression, and in favor of his own somewhat novel views. Material injected into the sub- arachnoidal space in animals traverses the supercer- vical and submaxillary glands. In man it can pass out in the optic sheath to the bulb, in the sheath of the facial and the acoustic as far as the internal auditory meatus— whence fracture of the petrous with tearing of the nerve sheath leads to oozing out of cerebro-spinal fluid—and finally to the lymphatics in the nasal mucous membrane, the supposed path of meningeal infection from nasal sources. The writer has recently shown that during the whole of fetal life in the human subject, there exist efferent passages for the cerebro-spinal fluid along the larger nerve trunks from the spinal cord, notably those from the lumbar enlargement. After birth, however, these promptly close up. In the lower animals they are more persistent. The subarachnoidal cisternze protect the large basal vessels from compression, and in like manner the peri- cellular spaces shield the enclosed cell and its process from shock and pressure. Further, the perivascular channels protect the brain substance (His) in a more gen- eral way. William Browning. LITERATURE (MODERN). General. Dwight : Anatomy of the Head, Boston, 1876. Langer: Blutgefasse der Knocken des Schadels und der harten Hirn- haut, Vienna, 1877. Kadyi, H.: Ueber die Blutgefasse des menschlichen Riickenmarkes, Lemberg, 1889, pp. 152. Browning: The Normal and Pathological Circulation in the Central Nervous System, Philadelphia, 1897. Arteries. Heubner : Luetische Erkrankungen des Gehirns, etc., Leipsic, 1874. Duret: Recherches anat. sur la circulation de l’encéphale. Arch. de Physiologie, 1874. Ibid.: Various previous articles ; also Gaz. médic., 1877, No. 4. Lucas, E.: Essai historique, critique, et experimental sur la circula- tion artérielle du cerveau. Thése de Paris, 1879. Wilder : American Neurological Association, 1885. Reported in Jour- nal of Mental and Nervous Diseases, July, 1885, pp. 348, 349. Windle: The Circle of Willis. Reports of British Medical Association for 1887. New York Medical Journal, ii., 1888. Done i Des ruptures de l’artere méningée moyenne, Paris, 890, p. 115. Adamkiewicz, A.: Die Arterien des verlingerten Markes vom Ueber- gang bis zur Briicke, Vienna, 1890. [Reprint.] Kolisko, A.: Ueber die Beziehung der Art. choroidea anterior zum hintern Schenkel der innern Kapsel des Gehirns, Vienna, 1891, p. 56. Veins. Rosenthal: De intimis cerebri venis, in Acta Acad. Leopold. Carol., vol. xii., Bonn, 1824. Labbé: Note sur la circulation veineuse du ceryeau. Arch. de Phys- iologie, 1879. Browning: The Veins of the Brain and its Envelopes, Brooklyn, 1884. (This work has been freely used in preparing the present article.) Hédon : Note sur la circulation veineuse de l’encéphale. Journal de Médecine de, Bordeaux, June 3, 1888. Hédon, E.: Etude anatomique sur la circulation veineuse de l’en- céphale, Paris, 1888, pp. 96. Browning, William: The Arrangement of the Supracerebral Veins in Man, as Bearing on Hill’s Theory of a Developmental Rotation of the Brain. Journal of Nervous and Mental Disease, November, 1891. Svijachenitioff, Grigor: [Anatomy of Veins of Posterior Part of Head, of Neck, and Base of Skull], St. Petersburg, 1889. (Treats of extra- cranial veins, emissaries, etc.) Sinuses. Trolard : Recherches sur l’anatomie du systéme veineux du crane et de V’encéphale. Arch. Gén. de Méd., 1870. Riidinger: Beitrige zur Anatomie des Gehérorgans, und der venésen Blutbahnen der Schadelhéhle, Munich, 1877. Knott, J. F.: Cerebral Sinuses and their Variations. Trans. Lond. In- ternational Med. Congr., 1881. Browning: Spaces Beside the Dural Sinuses, etc. of the Medical Sciences, October, 1882. Langer: Der Sinus Cavernosus der harten Hirnhaut. d. Wien. Akad., May, 1885. American Journal Sitzungsbericht REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. PLATE XIX. Representation (in the two lower pictures) of the condition known as *‘Choked Disk,” as seen with the ophthalmoscope. For purposes of comparison, the appearance of the normal fundus oculi is shown in the upper picture.—( From Haab—Aitlas of Ophthalmoscopy.) ” 1 “Lae wal 4, — ‘) 7 are > aa So a a ia a nas - “5 4 . ne - s md 7 a yae 4 le - the oo =P “wa a = 2 7% ee Ek cy + tes = a 7 { ® wa ; . ' ) 30 ee aes : er ae AS g en) | i 4 : + m< . ~ > ry z a ~ . me. = nt : 7 = = mm 7 ’ ie? ae =e 4 ta , ae ear f matt ui ae . Mi ae a 4 * th, ‘ LIBRARY OF THE UNIVERSITy of ILLINOIS. a i mat a @ 4¢ _ 1 Ye 3 ‘ ‘ x oy REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, Lymphatics. Many articles by Arnold (1888), Hyrtl (1860), His (1865), Robin, Schwalbe, Obersteiner (1870), Riedel, Arndt, Krause, etc. Key and Retzius: Studien in der Anat. des Nervensystems, ete., 1876. Rossbach and Sehrwald: Uber die Lymphwege des Gehirns. Centbl. f. med. Wiss., 1888, Nos. 25 and 26. BRAIN, COMPRESSION OF.—Notwithstanding the unhappy use of a word that does not describe the subtile condition it is meant to express, the term compression is a convenient one that seems justified by the necessities of analysisand study. It is generally used ina pathological sense to describe a complexity of symptoms arising from a particular state of the brain characterized mainly by disorder of the circulation within the cranium, and mani- fested by more or less derangement of the three great faculties of the nervous system. As a principle used to account for the phenomena of brain disease, and as a complication that is often present after various lesions of the brain and its membranes, the special and differential diagnosis of compression is of grave importance, and includes a wide range of cerebral pathology. The prevailing opinions of writers on this subject are somewhat misleading, since compression, in its true sense of occupation of less space, is a condition of the brain which in most cases seems to be assumed rather than demonstrated to exist, and it is rare to find a case of compression in which there are not present the symptoms both of concussion and laceration of the brain. Errotocy.—The squeezing of its constituent parts or the diminution of volume that is,supposed to interfere with the functions of the brain may be effected by press- ure from without the encephalon, or by tension within its proper substance. ‘The condition arises from a great variety of causes, most common of which are cerebral tumor, hemorrhage, and inflammatory foci. Hyper- trophy of the brain, simple congestion, hydrocephalus, and effusion from various causes may result in compres- sion. The effusion may take place quickly or slowly. Some experiments, however, point to the fact that the symptoms of compression are not to be attributed to augmentation of tension of the cephalo-rachidian liquid. Other causes are foreign bodies, loose splinters, or larger portions of depressed bone, and, in fact, any in- jury of the head, whether simple contusion, scalp wound, or fracture of the skull. Whatever be the cause of com- pression, it should be borne in mind that the most char- acteristic symptoms are brought about by sudden action, for compression established slowly upon the brains of animals by the injection of a liquid causes no apprecia- ble symptom, unless the quantity injected be unusually large; and it should be further remembered that, in the human subject, appreciable symptoms of compression are not always induced by such causes as sanguineous extravasation into the cranium and the cerebral ventricles, nor by the pressure of a foreign body, a tumor, or a fracture. Symproms.—Loss of consciousness and paralysis, which vary according to the seat and extent of the compression, are symptomatic of the condition, no matter whether the compression be sudden, like that following a wound or some mechanical injury of the skull and its contents, or whether it be slow, as that following enlargement of the brain from extravasation of blood, lymph, pus, serum, or tumors. Paralysis, excepting that of one or the other eye, is always on the side opposite to that which is the seat of injury. Thesymptoms may come onalmost immediately after any injury of the brain that disorganizes its sub- stance; but there are other cases in which compression takes place slowly and after a certain lapse of time. The initial symptoms that characterize this period are mainly subjective and those of congestion, as vertigo, head- ache, confusion of ideas, nausea, and, on rare occasions, vomiting. Then follows a lethargic sleep and more or less paralysis, and the patient cannot be aroused by any stimulus. The face is suffused and dusky, it wears an expression of well-pronounced stupor, and the eyelids are usually closed and immovable; respiration is slow, labored, and stertorous, something like the act of snor- ing, and thé peculiar blowing movements of the lips in expiration have been compared to the act of smoking a pipe. Deglutitionisimpossible, and the tendon reflexes are abolished. As the intracranial trouble increases the pulse becomes slow and labored. It may be hard and frequent, or small and intermittent. Sometimes it is very irregular, and the symptoms may resemble those of anemia of the brain and medulla, brought about by ex- perimental means. Paralysis of the sphincters is gener- ally present, with involuntary evacuations; or the patient may have torpidity of the bowels and obstinate con- stipation. Retention of urine, often present from pa- ralysis of the bladder, is followed by incontinence as the result of overflow from distention. The skin may be cool or it may be hot and perspiring, and the tempera- ture, though generally normal, may reach as high as 106° F. One or both of the pupils may be contracted or dilated, or they may rest immobile and unresponsive to the action of light. Thesymptoms of optic neuritis may also be present, and sometimes nystagmus is noted. Pa- ralysis both of motion and of sensation, in one or both ex- tremities, may exist in case the compression is exercised on the hemispheres, and convulsive movements and twitching of the limbs may occur on the paralyzed side or on the opposite side. Death occurs from arrest of respiration. (See Coma and Asphyzia.) Driaenosis.—These pathognomonic symptoms, which are chiefly owing to effusion under the dura or to fracture of the inner table of the skull with resulting secondary anemia, are not always met with, nor do such injuries as those inflicted by nails and arrow-heads driven into the skull, and even by missiles lodged in the brain, always produce the symptoms of compression. Sometimes the brain may be compressed without any disturbance of its functions. Pressure from an abscess, causing a hollow in the brain as large as a man’s fist, has been known to cause no symptom of compression. Itis, moreover, doubt- ful whether depressed fracture be a frequent cause of compression, since the injury is always complicated by laceration, the symptoms of which are often mistaken for those of compression; and it is often difficult and al- Ways embarrassing to determine, after an injury of the head, whether we have to deal with a contusion of the brain, a simple concussion, or the more problematical symptoms of cerebral compression. One state so often merges into the other that the attempt to establish a clear basis for a sure diagnosis of the respective conditions seems hopelessly confused and intricate. Roughly speak- ing, the most characteristic symptom of concussion is somnolence and intensity of the evil from the outset; contusion manifests itself by agitation, delirium, convul- sions, contractions, and the delay of febrile symptoms; while the most salient symptom of compression is paraly- sis, except in the case of effusion of blood into the convex- ity of the hemispheres or into the ventricles, when con- tracture or tonic muscular spasm of extended duration is the more prominent phenomenon. Without being a sure sign, paralysis constitutes at least a valuable element in the diagnosis of a condition that has no single confirmative sign. If there be an unequivocal sign of cerebral com- pression in the majority of cases following injuries of the head, it is, perhaps, that furnished by obstruction of the venous circulation, in consequence of which the blood of the eye is not returned into the cavernous sinus, when we find with the ophthalmoscope papillary or peripapillary congestion, a general or partial serous infiltration of the papilla, and astrong dilatation with tortuosity of the ret- inal veins. (These appearances are shown in the accom- panying colored plate.) In concussion the fundus of the eye retains its normal state; in compression there is al- ways serous peripapillary infiltration, dilatation, tortuos- ity, and sometimes thrombosis of the veins’of the retina. The intraocular changes herewith portrayed are not al- ways pathognomonic, but they lend to the diagnosis an additional source of correctness. As arule, when the eye- grounds show arrest of the retino-choroidal circulation, we have an indication of the arrest of cardiac circulation and of the nervous functions. 265 Brain. Brain. ParHnoLoey.—According to many observers, the gen- eral sy mptoms of compression are owing to cortical anemia, and the general impairment of cerebral function is owing to disturbance in the capillary circulation, which prevents the normal interchange between the plood and the tissues, and results in phy siological death of the af- fected portion of the brain. In compression, the blood may be extravasated upon the surface of the brain, the effusion taking place between the skull and the dura, and in the cavity of the arachnoid, or in the intervening spaces that separate the membranes from the brain, or it may be effused into the ventricular cavities, or into the substance proper-of the brain. The volume of an ex- travasation between the dura and the bone is sometimes very large; but, as a rule, effusions of this kind are al- ways much larger at the v ault of the cranium than at its base. Sanguinary effusions between the dura and the pone, according to the summarized opinions of writers on the subject, generally coagulate into a firm clot that may either be absorbed or undergo organization and be- come adherent to both the bone and the dura, This clot never becomes encysted as do clots in the cavity of the arachnoid, but may undergo ossification. It is also sus- ceptible of other changes. Thus, for example, it may lead to necrosis of the neighboring bones of the skull, which may be perforated by an abscess having as its foyer the sanguineous effusion. Blood extravasated between the layers of the arachnoid, especially on that part which covers the cerebrum, is of common occurrence in the severest head injuries, and forms at the convexity of the hemisphere a thin, evenly spread layer. It clots rapidly, loses its coloring matter, undergoes organization, assuming the form of a false membrane or of a membranous cyst, and may be absorbed and take on a secreting action like other cysts. Effusions between the visceral layer of the arachnoid and.the pia are less common than those in the cavity of the arachnoid, and are generally associated with some in- jury of the brain itself. They spread extensively into the spaces usually occupied by the cerebro-spinal fluid, and do not become encysted as in other situations. Traumatic effusions into the brain substance may occur inany situation. They are generally associated with lacer- ation or other severe injury of the brain, and are for the most part fatal. Should recovery take place, the blood clot undergoes changes similar to those observed in the organi- zation of an ordinary clot from cerebral hemorrhage. All effusions of blood between the dura and the brain are susceptible of being reabsorbed, of being encysted in a false membrane, and of giving place to encephalitis, meningitis, and other grave symptoms that come emi- nently within the province of surgery ; in fact, it is chiefly from this point of view that compression has been treated by the great masters. Clinical and experimental facts show that in compres- sion from injury of the occipital region death results not from failure of the heart, as often surmised, but from failure of the respiration. The symptoms are not me- chanical but depend on trouble of circulation inthe bulb, and have their point of departure in the cortex of the hemispheres including the vaso-motor centre. In place of attributing many of the troubles grouped under the subtile heading of compression to pressure ex- erted upon the brain, it would be better to attribute them to congestion, to contusion, to laceration of the cerebral substance, and to interference with the function of the respiratory centre, which puts us in a position to doubt whether the effects of compression upon the brain are not susceptible of further and more convincing proof. Procnosis.—The integrity of the brain is not compro- mised by mere compression itself, nor is the condition a very fatal one. Its gravity depends on consecutive in- flammation, secondary ansmia, and the effect on the respiratory centre. Sometimes the symptoms disappear spontaneously and gradually without interference. The TREATMENT of compression raises many questions of operative interference, which are discussed elsewhere under their respective headings. The whole end of treat- 266 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ment is to restore interrupted respiration and prevent cerebral inflammation. In endeavoring to do this, artifi- cial respiration and heat to the head by irrigation appear most commendable. Irving C. Rosse. BRAIN, CONCUSSION OF THE.—(Concussion of the cord is analogous to concussion of the brain.) The term “concussion of the brain” comes down to us from the earliest ages; it was used by Hippocrates, Galen, and Cel- sus; its modern significance was given it by Boirel, but it was Littré who first studied the subject post mortem, in 1705, The subject of concussion of the brain, or commotio cerebri, has received much attention from various work- ers, especially in the last fifty years. The theories con- cerning it have varied widely, even to the extent of contradiction. The general cause of this condition—trau- matism—and the characteristic symptoms of the same— sudden unconsciousness, feebleness of heart and respira- tion—are well known; but what occurs in the cells af- fected is as yet undiscovered. Verneuil, the eminent French surgeon and writer, after much observation and experience on this subject, formulates the following definition: “It is a series of phenomena occurring more or less suddenly which result from a mechanical shaking (jarring movement) of the anatomical cells, tissues, and organs, characterized by temporary excitation or depression of the properties, offices, or uses of the parts which are shaken; and as a result there are caused anatomical changes similar to those which are normally seen in the successive phases of functional activity and functional repose.” According to Pick, this term was first used because there was thought to be a shock and molecular disturb- ance to the cerebral tissues with no visible lesions or lacerations. This cannot hold, since the autopsy almost invariably discloses macroscopic lesions. However, these lesions are not necessarily the cause of the insensibility. It has been shown by William Savory that the state of unconsciousness and insensibility passes away, while the lesions remain. In many cases the extent of the lesion is not sufficient to produce the existing symptoms, and, again, the lesions may be present when there is no insen- sibility. There are three grades: mild, severe, and fatal. In explanation of the mildest grade the following has been offered: The cerebral cortex, owing to’a momen- tary deprivation of nutrition, following lowered blood pressure and fall of temperature, ceases for the time being to function, and so follow loss of memory and uncon- sciousness. In the more severe type the molecular disturbance is more violent and is naturally followed by graver symp- toms. Mental functions are temporarily suspended, the condition of the patient somewhat resembles sleep, al- though the eyes are often in motion unnaturally with closed lids; or if at rest, they are not upturned and di- vergent as in normal individuals. This may be termed “the sleep of concussion.” There isnosnoring. Indeed, there may be disturbances of the cardio-pulmonary func- tions or paralyses of different parts of the body from localized lesions of the brain. In the fatal form, death may follow at once or after a few hours. ErroLocy AND PatTHoLocy.—The gross cause of cere- bral concussion is, beyond doubt, some form of trauma- tism either applied directly to the head or indirectly transmitted, as in the case of a fall upon the feet—when the shock is transmitted through the spine,—or in that of a blow or a fall upon the chin. But the changes pro- duced in the brain substance and the subsequent results have been the subjects of much argument. Treves groups the theories of concussion under three heads: 1. Molecular disturbances. 2. Multiple hemorrhages. 3. Vascular disturbances. In the molecular form of disturbances the brain sub- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. stance is thrown into vibrations by the violence trans- mitted to it. The old idea that obtained, viz., that there were no macroscopical lesions, has been entirely over- thrown by modern workers, for, as has been noted, in all fatal cases which come to autopsy macroscopical lesions consisting of hemorrhages or lacerations are almost in- variably discovered. Not infrequently, however, these hemorrhages are too insignificant to be the cause of death or even of the symptoms of concussion. That cerebral anemia exists is hardly disputed. The cause of this ane- mia has offered a field for discussion. Duret describes “the cone of depression and the cone of bulging,” meaning by the first the point which re- ceives the injury and by the second the area just oppo- site. The force of the injury imparts to the cerebro- spinal fluid an impetus which drives it from the lateral ventricles into the third ventricle through the aqueduct of Sylvius into the fourth, and the latter, receiving more fluid than it loses, becomes distended. This distention causes a stimulation of the restiform bodies resulting in cerebral anemia. Duret also believes that the small hemorrhages are due to the blood-vessels losing the sup- port of the cerebro-spinal fluid. Anzemia may exist by displacement of blood following the indentation of the skull. According to Fischer the loss of vascular tone may result from the nervous shock of the injury and may cause permanent vascular degen- eration. Emotion is probably followed by a loss of vas- cular tone. The results of shock are sometimes similar. Possibly this mechanical vibration causes both physical and chemical changes in the nerve cell. Phelps believes that the stimulation of the restiform bodies resulting in efferent reflex action causes direct capillary contraction. After the cortical centres have received a shock there is instituted an instability of cerebral nutrition due prob- ably to increased sensitiveness of the vaso-motor centres and a liability to anemia or hyperzemia from very slight causes. Oftentimes individuals after head injuries are unable to undergo severe labor or exposure to the sun or the effects of alcohol. These facts were clearly recog- nized in the late Civil War, for men who had suffered in- juries of the head were relegated to the invalid corps. Symproms.—The most characteristic symptoms of this condition are sudden unconsciousness, loss of memory for events just preceding or during the injury, muscular weakness, dulled sensibilities, general prostration, vomit- ing, and changes in the circulatory system, as illustrated by the respiration and the pulse. These symptoms vary in their intensity and duration in accordance with the severity of the injury sustained. They may be very slight, consisting only of momentary unconsciousness, pallor, and mild interference with respi- ration; or they may be so severe as to be followed by death in afew moments. Treves notes three stages: 1. Stage of collapse. 2. Stage of reaction. 3. Stage of convalescence. This is a convenient and comprehensive classification. The clinical picture of the mildest grade is illustrated by what is familiarly known as the state of being “stunned.” In this condition the patient hears strange noises, there are visual disturbances, dizziness, general weakness, inability to stand or to use the arms; the eyes lose their natural expression, the eyelids close. The pulse is always weak; sometimes it is slow, at other times it is rapid—more generally the former; and it is probable that immediately after the injury it is always slow. Respira- tion is disturbed, irregular, and now and then of a sigh- ing character. The paralysis which occurs is generally only temporary as well as functional, for these phenomena disappear with returning consciousness. In cases of well-marked concussion the superficial re- flexes and knee-jerks are not pronounced, neither are the cranial reflexes. In slight cases these are sluggish. A common symptom is delirium. This may be violent or mild, the nocturnal form being most characteristic in cases of cerebral traumatism. Brain, Brain, In the more severe cases the symptoms are more accent- uated. The unconsciousness may amount to coma, the patient being incapable of being aroused; he cannot even swallow. There are successive attacks of vomiting; the pulse is irregular, small, and generally very slow. Res- piration can scarcely be detected. The skin is cold. The pupils are. equal and more or less dilated, their reaction to light varying with the extent of the injury. There is incontinence of rectum and bladder, for although the sphincters of these organs are relaxed the organs themselves are not paralyzed. The temperature is the same on both sides of the body; rectal temperature is in- variably subnormal, even falling to 95° F. In the stage of reaction there is a general improvement in the bodily functions. The temperature rises, the skin becomes warm, circulation improves, respiration is stronger, and the pulse gradually becomes normal. This stage is ushered in by vomiting. Consciousness comes back by degrees, and with returning consciousness head- ache oftensupe:venes. The loss of memory noted in this stage may refer only to events just preceding the re- ceipt of the injury, or it may also include those which oc- curred at the time of injury. The loss of memory may continue for some time after consciousness is fully re- gained. During this stage the patient may die with symptoms of encephalitis or of spreading edema. Effu- sion of blood may often cause death in injury to the head with or without any marked external injury. Effusions may occur upon the surface of the brain after superficial lacerations of its substance. The duration of the stage of convalescence may be from a few days to weeks or even months. When re- covery is prolonged it is fair to assume that laceration has taken place. Such an hypothesis would also ac- count for those cases in which complete recovery never takes place and in which mental disturbances persist. DraGnosts.—Concussion of the brain should be differ- entiated from opium poisoning, alcoholic coma, com- pression, and contusion. From opium poisoning it should be distinguished by the narrow pupils and stertorous breathing, which serve as diagnostic differences. It is often of medico-legal importance to diagnose this state from alcoholic coma. While in the latter the odor of alcohol might at first sight seem conclusive, it must not be forgotten that the brain lesion may also be present, having been received after the alcohol had been taken; also that alcohol in some form may have been given after the receipt of the injury. At all events, when a perfectly clear history pointing unmistakably to alcoholism cannot be obtained, give the patient the benefit of the doubt and treat with a view to the existence of the possible brain lesion, opium of course having been excluded. Bourneville differentiates apoplexy and non-traumatic hemorrhages from concussion by the temperature, which is subnormal] in the former, later becoming normal when recovery is to take place, but rising to an extreme degree in cases that terminate fatally; whereas in traumatic lesions the temperature rises at once while the results are uncertain. The history will also throw much light on the diagnosis. Between concussion and compression the following table will be found to contain the points of differentiation: Concussion. Onset of symptoms immediately after injury received. Onset sudden. Immediate uncon- sciousness. Muscular system generally re- laxed, no definite paralysis. Pulse always weak, generally slow, sometimes rapid, and ir- regular. Respirations slow and shallow, may be sighing. There is incontinence of urine. The pupils are equal, dilated, and react to light. The surface temperature is equal on the two sides. Compression. Onset of symptoms some time after receipt of injury. Headache and drowsiness, grad- ually increasing to unconscious- ness. Definite paralysis, local or gen- eral. Early slow, becoming rapid as the condition advances. Early respiration is regular and slow, later becoming irregular, resembling Cheyne-Stokes. Retention and overflow of urine. Pupils are irregular till the last stage, then are dilated and do not react to light. neansaaarbe teh is generally irregu- ar. 267 Brain. Brain, Proenosts.—The prognosis must always be guarded. In slight cases recovery is generally to be expected. Unfavorable signs are coma, very slow pulse, convul- sions, and paralysis. Signs of compression and of lacera- tions in the stage of reaction modify the prognosis. TREATMENT.—The treatment must vary with the stage at which the case is seen. If an external wound exists it must be treated, as in ordinary cases, according to its character. General directions for the stage of collapse are to regulate the depression of the circulatory and respiratory systems by means of warmth applied to the body; stimulants may be administered by the mouth if the patient can swallow; per rectum, or hypodermatically. Alcohol is contraindicated unless stimulation is indicated. The stimulants that may be used are ether, musk, strych- nine, atropine, sparteine, nitroglycerin, camphor; coun- ter-irritants such as sinapisms may be applied over the precordium and epigastrium or to the calves of the legs. If the patient continues to be unable to swallow he may be fed through a stomach tube or per rectum. Black coffee enemata are also useful. é In the stage of reaction stimulants should be withheld, the diet should be light, and the bowels should be kept open by purgatives and enemata. Darkness and quiet are essential. When recovery is delayed shaving the head and the application of cold by Leiter’s bags are to be commended; calomel and salines are beneficial. In the stage of convalescence the patient should not be permitted to work and should be shielded from all men- tal excitement. Fresh air, rest, and light diet are es- sential. Chloral hydrate and potassium bromide are indicated in cases of irritation. Potassium bromide aids in pre- venting inflammation. There must be no constriction at the neck; the head must be kept low; the scalp should be shaved and examined with care, for in fractures of the skull there are often no symptoms of a concussion for days or even weeks. “ Railway spine” or spinal concussion, formerly used to describe the results of concussion, is a misnomer. Traumatic neurasthenia may result; this is similar to the condition following injuries to the spine when health, on account of organic disease or of overstrained nerves, is at a low ebb at the time of the injury. Traumatic in- flammation of the brain or of its membranes may result. Abscesses may also follow. Cerebral irritation is a condition sometimes following concussion. Its symptoms are probably owing to bruis- ing of the frontal lobes. The patient lies on the side with the limbs curled up and is unconscious. He is rest- less and very irritable; the eyelids are closed; the pulse is slow—from 40 to 50; there is an absence of heat in the regions of the head and spinal cord; and generally there is incontinence of feces and urine. This condition may continue for as long a time as three weeks. The patient then extends the extremities and as- sumes the supine position. ‘The temperature becomes nor- mal, the pulse more rapid, and recovery may supervene. On the other hand, the mind may be permanently affected. There is absence of memory during the illness. The findings at the autopsy table have been substan- tiated by the animal experiments performed by Koch, Fiehlene, Wittkowski, Albert, Goltz, and others. Emma E. Walker. BRAIN, DEVELOPMENT OF THE.—The develop- ment of the brain is bound up with that of the nervous system at large. While in the lower animals the nerve cells appear scattered or grouped in various parts of the body, and such scattered ganglion cells are found in even the highest animals, yet it is characteristic of the central nervous system as found in vertebrates that the nervous structures are collected into a common aggregate which contains only such admixture of other than nervous tissue as may serve to protect, support, and insulate the latter. It is obvious that the ordinary vegetative func- tions of life and many adaptive processes may be satis- factorily performed without a nervous system as such, 268 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. as may be seen in the higher plants. The development of a central system, then, is an indication of preparation for higher functions than those of nutrition and metabol- ism or even of complex adjustment to the environment. Harly Stages.—After the egg has been differentiated into an animal and a vegetative pole and after the vegeta- tive cells (by a process of invagination or substitute for it) have acquired an internal position, the cells remain- ing at the periphery (ectoderm or epiblast layer) repre- sent the rudiments from which are to spring all the cells and specific organs not only of the central nervous system but of the sensory apparatus which forms the avenue from the external world to the central system. The ectoderm also contains, of course, the forerunners of the cells of the epidermis at large. In general, the rudiments of the central nervous system collect in a broad longitudinal band extending along the dorsum of the embryo, while the rudiments of the sense organs exhibit a tendency to be arranged in one or more series along either side of the central band or medullary plate (Fig. 822).* In lower, especially aquatic, forms this lateral sensory band is evident in late life as the series of lateral-line organs, and it is plain that some or all of the Fic. 822 (Nos. | to 4).—Transverse Sections through the Neural Plate and Neural Tube of an Embryo Bird. chd, Notochord; hy, ento- derm; mf, neural folds; mg, neural groove ; mp, neural plate; ne, neural canal; nt, neural tube; so, somatopleure; sp, splanchno- pleure. (Mihalkovics and Balfour.) In No. 4 the rudiment of the spinal ganglia is represented but not lettered. organs of special sense obey the same law of serial arrangement, the ear in particular betraying relation- ships to the lateral-line system. (Compare Vol. I., p. 627.) The Newral Plate and Tube.—The neural or medullary plate is supported from below by a band of cells derived from the original. entoderm which separates from the latter to form a solid rod (perhaps theoretically a tube at one stage), called the chorda dorsalis. The medullary plate grows more rapidly than the adjacent ectodermal tissue, and thus forms a raised border on either side with a groove in the median dorsal line. This medullary groove is continuous behind with the lip of the blastopore or opening left after the invagination of the entoderm. As the lateral margins of the medullary groove rise higher above the surface (both nervous and epidermal portions participating in the growth), the groove is trans- formed into a tube. The concrescence of the lips of the fold begins at a point corresponding with the site of the future midbrain. In the vicinity of the blastopore the groove may remain open for some time, and there is formed a direct communication with the primitive digestive tract through what is known as the canalis neurentericus, a *These and several of the following cuts are introduced without change from the article by Professor H. F. Osborn in the former edition. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. communication that is disturbed only by the final closing of the blastopore. At the cephalic extremity also the closing of the tube is long delayed, and there is left an opening called the neuropore communicating with the exteri- or at the front of the head. In bony fishes and other verte- brates whose eggs have much yolk, the tube may be formed first aS an ap- parently solid cord of cells, but the final result is the same. At the cepha- lic extremity of the digestive tract, which at this stage ends in a blind sac separated from the pharyngeal invagination by the portion of the ectoderm known as the septum of Remak, is a region of fusion called the area reuniens. Here the cephalic end of the chorda, the base of the brain tube, and the angle of the enteric cavity tend to adhere temporarily. On the cephalic side of the septum the ectoderm gives rise to (an appar- ently single) median in- vagination which ex- tends dorsally to meet a similar outgrowth of the infundibular region of the brain, combining with the latter to form the hypophysis or pitu- itary body. On the op- posite side of the sep- tum a somewhat similar outgrowth from the cephalic dorsal angle of the digestive tract forms the so-called Seessel’s sac, which in some cases seems to connect with the cephalic end of the chorda. In birds at least this sac is distinct from the chorda which subse- Fig. 823.—-Median Section of Brain of Bird Em- bryo, to Show Hypophysis and Pharyngeal Sac. Fig. 824.—Later Stage of Hypophysis. Fia. 825.—Illustration Showing the Relation between Chordal Sac, Alimentary Canal, and Brain Flexure in Opossum. (From Selenka.) quently degenerates and leaves a convoluted thread-like vestige behind it that is closely connected with the site Brain, Brain. of origin of Seessel’s sac. The latter, after the breaking through of the septum, comes, in birds, to lie in connec- tion with the base of the hypophysis (Fig. 828). This region seems to mark the morphological front of the head, and the medullary tube is often open at front, forming a neuropore (Fig. 826). Gradually the tube ex- tends cephalically, and the base and roof unite along a line a part of which becomes that part of the base of the Fie. 826.—Brain of Torpedo, to Show the Neuropore, 7.p. brain occupied by the postoptic and preoptic recesses, the remaining part being the lamina terminalis (Fig. 826). The portion of the brain developed cephalad of the area reuniens, 7.¢., in front of the cephalic end of the chorda, is called the prechordal as distinguished from the remain- ing, or epichordal part of the brain, and is morphologi- cally different from the latter. In early stages of the de- velopment of the brain tube it appears segmented, and many attempts have been made to prove that these seg- ments, or neuromeres, have a morphological significance and that they correspond with the segments discoverable in other and especially the mesodermal tissues. It has also been supposed that evidence of this primitive seg- Fig. 827 (Nos. 8 to 14).—Horizontal Sections of the Forebrain (8 and 9, of abird; 10to 14, of arabbit). (K6lliker, Mihalkovics, L6we.) cal, Corpus callosum; chd, choroid plexus; fmr, foramen of Monro ; frx, fornix; hms, cerebral vesicle ; hemisphere; inf, infundibu- lum; msc, mesencephalon; stm, stem; str, corpora striata; trm, lamina terminalis ; thm, optic thalami; ve, ventriculus communis ; vtr, fifth ventricle; v’, lateral ventricle ; v3, third ventricle. Other letters as above. mentation could be seen in the arrangement of the roots of the cranial nerves. On the whole, however, it must be admitted that, while it is not difficult to detect the segmental arrangement in the epichordal part of the brain, the prechordal portion either was not derived from 269 REFERENCE HANDBOOK OF THE MEDICAL. SCIENCES. FIG. 828 (Nos. 15 to 19).—Vertical Sections of the Brain (15 to 18, of the rabbit; 19, of the bird). (Mihalkovics.) cbl, Cerebellum ; chd4, tela vasculosa ; chd3, choroid plexus of third ventricle ; epc, epen- cephalon ; hph, hypophysis; it, iter; psc?, prosencephalon ; psc}, diencephalon ; pns, pons Varolii; smr, sulcus of Monro; v4, fourth ventricle. a segmented rudiment, or, if so, it has suffered such complete alteration as to Lam. berm: StSERZ» Ee Optv, Wf-b. Fig. 829.—Dorsal View of Chick of Fifty-Eight Hours. (After Mihalkovies.) Lam. term., Lamina terminalis ; F’-b., fore- brain; Opt. v., optic vesicle ; M-b., midbrain ; H., heart. prevent the identification of the neuromeres.* In all vertebrates the por- tion of the medullary tube destined to become brain is divided at an early stage into three embryonic vesicles, the forebrain, midbrain, and hind- brain respectively (Figs. 827 and 829). Inall higher verte- brates the midbrain is the site of a very important flexure which is formed at an early embryonic stage and causes the forebrain to assume a ven- tral position with reference to the remainder of the brain. The division into three lobes homologous with the vesicles may take place in some cases before the closing of the tube, but this may be looked upon as an instance of retardation in the development of the tube and is of no morphological significance. Embryonic Brain Zones.—After the closing of the F1G. 830 (Nos. 30 and 31).—Transverse Sections through the Forebrain of a Rabbit, Showing the Development of the Optic Vesicles and Rudimentary Parts of the Eye. (K6lliker.) 1, Lens; hph, hypoph- ysis ; opt!, primary optic vesicle ; opt?, secondary optic vesicle. medullary tube the dorsal and ventral median portions are thinner than the lateral walls and have been called * Locy and his school identify eleven neuromeres in the brain, five of them being cephalad of the cerebellum. 270 by His basal plate and roof plate respectively, though they are rather lines or zones than plates. On either side Fig. 831.—Figure of Hu- man Embryonic Brain. (From His.) A, Optic vesicle ; H, prosenceph- alon; Z, diencephalon ; M, mesencephalon; T, isthmus; Tr, infundib- ze ulum; Pm,mammillare; Br,pons; Hh, cerebellum ; Rf, roof of fourth ventricle ; Gb, auditory vesicle; VV, medulla; Nk, cervical flexure. Fic. 832.—Youngest Stage of Ichthy- ophis. J, Infundib- ulum; — shaped figure. The stem is directed obliquely ventrad and intersects the gyrus fornicatus. The parieto-occipital fissure forms the more direct con- tinuation of the stem, and continues on the ectal surface as the external parieto-occipital fissure. The calcarine branch passes toward the occipital pole. The stem is called the anterior calcarine fissure. The apex of the cu- neus gives off two deep annectant gyri—the gyrus cunei and anterior cuneo-lingual gyrus. The gyrus cunei forms a barrier between the parieto-occipital fissure and the stem, while the gyrus cuneo-lingualis anterior separates the stem and the posterior part of the calcarine fissure. The calcar (hippocampus minor) is formed wholly by the stem or anterior calcarine fissure. In apes the calcarine fissure -is deep and much more stable than the parieto-occipital. In the chimpanzee the gyrus cuneus is on the surface (a condition found in 3.9 per cent. of human brains), while in the orang and gib- bon the cunei may be on the surface or at the bottom of the fissure. The gyrus cunei is never absent. Cunning- ham believes that the whole calcarine fissure of anthro- poids corresponds to the “stem” of the human calcarine; or rather, the whole length of the precursor of the human calcarine is the equivalent of the ape calcarine. The posterior calcarine of man is of later origin and takes the place of an abolished portion of the original fissure. The cuneus of the ape does not have the same morphological value as that of man. Only the cephalic part is present in the ape; the caudal part is absent or blended with the gyrus lingualis. In the ape the entire length of the cal- carine fissure is on the tentorial face of the hemisphere. The posterior calcarine fissure is distinct from the “stem” in origin, the latter being a “complete fissure ” and having unbroken continuity of existence with the fore-part precursor. T he Occipital and Parietal Indices are the distances along the mesal margin of the hemisphere intercepted by the intersection of the external parieto- -occipital fissure and the fissure of Rolando respectively; in the first case the measurement being taken from the occipital pole, in the second from the parieto-occipital intersection, and both these distances being given in terms of hundredths of the entire length along the dorsal margin of the hemisphere. For the human brain the following averages are given: 3 T0656 MONS saree vues risteteie OY index, abe peh ea A index, 28.5, to 7% months.. oe 18.6: 24.7. 6: to 844 months.. na 20.7 ; Pe 24.1 Full-time foetuses.. eS 20.8 ; bie 25.7 Mirstl2 MONS ..cns a ecerciet eee %y 22.3 5 PS 25.6 AAD VORIR. co tiece seve sais ieleerers sts a 23.2; x 24.2 WN foe GR (el he emma nee eneers My 20.8 ; ‘a 27.4 PA CHUTIES sesistisucits oraleidiaisietre alete etecaiite 3 21.25 ve 25.5 Brain. For apes the following table is given: OVATI Osa dernetstessteie tierce qanmersreare oO. index, 23.23 P. index, 21.3. OHIMPANZESeaciceciee as ai sieisiee ets 24.2 ; 19.9. Fiamiadr yas). cecctcntse aeaemaratiese i 29.5 ; 20.5. Gynlocepnalusiieecne cece concen eee ONT ss ihe 22, 6. MAnNGaby cc ienitiencsaedon cence: i 30.5 ; ry 24.1, MaCAQle:.aaeoneousiiere cence hy 31.0; = 19.0. Cercopithecusst..cdacsae vs ace en's ‘i 32.9 3 hy 19.0 COD UB eerccatelal terse nlectereceisrenstanners Ms 33.1; ny 20.6 The low parietal index and high occipital index are in- structive features. In low apes there is an enormous in- crease in the occipital portion of the border; whereas in the high apes the amount of increase is smaller. The relative shortness of the parietal border in high apes is due to the relative increase of the occipital and frontal borders. In low apes the reduction of the parietal por- tion is entirely due to the great size of the occipital lobe. The following summary is reproduced verbatim: 1. At an early period in the development of the cere- bral hemisphere a series of deep infoldings of its thin walls make their appearance. On_the exterior of each hemisphere these show in the form of sharply cut linear fissures. 2. Certain of these fissures, are permanent; the great majority are transitory. 3. The transitory fissures, with two exceptions, have disappeared by the time the corpus callosum is fully formed. 4. A deficiency of the corpus callosum is associated with a persistence of the temporary fissures. 5. The temporary fissures indicate an important stage in the growth of the cerebrum, and are apparently asso- ciated with the mapping out of the occipital lobe. 6. A quadrupedal pause in the growth of the cerebrum brings the skull capsule into antagonism with the growth of the hemispheres, and, in consequence, the wall of the cerebrum is thrown into folds. These folds disappear as the occipital lobe assumes shape, owing to the expansion of the cranial cavity, and a restoration of growth har- mony between skull and brain. 7. Consequently it is only in Primates, which alone possess well-developed occipital lobes, that tr ansitory in- foldings of the cerebral walls in all pr ‘obability exist. 8. The two transitory fissures which do not disappear before the full development of the corpus callosum are: (a) the external calcarine, and (’) the external perpen- dicular fissure of Bischoff. In point of fact the latter fissure does not appear until after the full development of the corpus callosum. 9. The external calcarine fissure produces an infolding of the outer wall of the posterior horn of the lateral ven- tricle, which presents the same direction, and lies imme- diately opposite to the true calcarine infolding, or the calcar avis. 10. The fissure corresponding to this in apes is, as a rule, permanent, and in some species its anterior end forms in the adult a bulging on the outer wall of the ventricle. 11. The external calcarine fissure disappears before the sixth month of foetal life in man. 12. The external calcarine fissure is present on the outer surface of the fcetal cerebrum from the beginning of the fifth month to the end of the sixth month. 13. It is a complete fissure and corresponds to the “ Affenspalte ” on the ape’s brain. 14. The “ Affenspalte ” on the ape’s brain is also a com- plete fissure, and presents a well-marked bulging on the outer wall of the posterior horn of the ventricle; but, unlike the external perpendicular fissure of the human foetus, it is permanent. 15. Certain fissures, therefore, which are complete and temporary in the human brain, are complete and perma- nent in the ape’s brain. 16. The complete permanent fissures in the human are: (a) the fore part of the calcarine; (0) the hinder part of the fissura arcuata; (¢) in many cases the parieto-oc- cipital; and (d) in some cases the midcollateral. The Sylvian fissure is not a complete fissure. 275 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. 17. Of the fissura arcuata the hinder part alone is pre- served as the fissura hippocampi. The fore part, which is generally supposed to be retained as the callosal fissure, is in reality obliterated. 18. Synchronous with the appearance of the radial transitory fissures on the mesal face of the hemisphere two fissures appear, which lie in series with the former and occupy the ground afterward held by the parieto- occipital and calcarine fissures. These may be termed the precursors of these fissures. 19. The precursor of the parieto-occipital fissure some- times shows an unbroken continuity of existence with the parieto-occipital fissure of the adult brain. In other cases it is obliterated, and its place is afterward taken by a secondary sulcus, which attains, however, a very great depth. 30. In the adult brain the parieto-occipital fissure, even in its complete form, does not form any eminence on the inner wall of the posterior horn of the ventricle, because it does not extend downward as far as the cavity. Above its lower end the hemisphere is solid. 21. The posterior end of the calcarine precursor is in every case obliterated, and the anterior part retained. The extent of the part obliterated varies considerably in different brains. 22. The anterior preserved portion of the calcarine fis- sure forms the “stem ” of the >— shaped fissural ar- rangement on this part of the hemisphere, and its hinder part corresponds to the calcar avis. 28. In the place of the hinder portion of the calcarine precursor, which is obliterated, a secondary furrow ap- pears. This may be termed the posterior calcarine sulcus. 24. The posterior calcarine sulcus is formed in two pieces which run together and also form the “stem.” In this way the entire length of what in anatomical lan- guage is called the calcarine fissure is formed. 25. The posterior calcarine sulcus is not a complete fissure. 26. In the ape the entire length of the calcarine fissure is represented by that portion of the fissure which in man is termed the “stem,” and by that alone. The posterior calcarine sulcus does not exist in any form in the apes. 27. The cuneus, therefore, has a different morphologi- cal value in the apesand inman. In connection with this compare the abnormal human hemispheres. These exhibit certain conditions which approximate to those present in the apes. The Fossa and Fisswra Sylvit.—The sign of the Sylvian depression appears at the end of the second month of development. Dr. Cunningham summarizes his investi- gation as follows: “1. As growth proceeds the outline of the Sylvian fossa changes considerably. At first nearly circular, it elon- gates in a vertical direction and then backward on itself, and assumes a triangular outline. “2. The high prominent mantle border or rim which surrounds the depression is divided by intervening angles into four sections, viz.: the temporal (postoperculum), or lower; the fronto-parietal (operculum), or upper; the frontal (preoperculum), which is formed by an open- ing out and flattening of the primitive single anterior angle; and an orbital (suboperculum), or front portion. “3. Each of these portions of the bounding rim acts as an independent line of growth, and consequently, in course of time, four opercula grow over the Sylvian area so as to enclose it. The temporal and fronto-parietal opercula appear first; the frontal and orbital do not de- velop until a much later period. “4. The so-called three limbs of the fissure of Sylvius are formed by the meeting over the Sylvian area of the contiguous lips of the four opercula; the posterior hori- zontal limb intervenes between the fronto-parietal and the temporal opercula; the anterior ascending limb be- tween the frontal and fronto-parietal opercula; the an- terior horizontal limb between the frontal and the orbital opercula. “5. The frontal operculum is therefore the same as the ‘cap de Broca,’ and it shows great variations in its 276 length, It may be absent altogether, and then the two anterior limbs of the Sylvian fissure are fused into one. When the frontal operculum is reduced in length we have the Y-condition of the two anterior Sylvian rami. “6. The Sylvian fossa once mapped out on the surface of the hemisphere, it extends very rapidly. The growth is not proportionate with that of the hemisphere, it is much more rapid. “7. During intrauterine life the anterior end of the insula maintains a very nearly fixed position with refer- ence to the anterior end of the cerebrum, while the pos- terior end of the cerebrum moves rapidly toward the occipital pole. After birth the posterior end of the in- sula is fixed, while the anterior end, as growth advances, oscillates slightly—at first approaching and then retreat- ing from the anterior end of the cerebrum. “8. An anterior limb of the Sylvian fissures can be determined only by the following tests: (a) it must cut right through the entire thickness of the operculum and reach the furrow surrounding the island of Reil; (0) it must lie in front of the precentral sulcus. “9. A single anterior limb of the Sylvian was present in 30 per cent. of the hemispheres examined; the two anterior limbs, quite distinct and separate, were present in 37.5 per cent.; the Y-shaped condition of the two limbs was present in 31.5 per cent. “10. The two orbital limbs of the Sylvian fissure can- not be regarded as belonging to the same category of the true anterior limbs. They are not developed as primitive deficiencies in the orbital operculum. “11. The posterior insula is not connected with the ex- tremity of the temporal lobe, as Erbstaller has asserted, but with the limbic lobe. “12. On the surface of the foetal insula there appear three radial furrows which correspond in every respect with the three ‘Primiirfurchen’ on the outer surface of the mantle (viz., the fissure of Rolando, the inferior pre- central sulcus, and the vertical limb of the intraparietal sulcus). The radial furrows on the insula clearly belong to the same fissural system and intermediate links be- tween the three radial fissures on the outer surface of the hemisphere, and the three radial fissures on the insula may exist in the form of secondary sulci, cutting the margin of the fronto-parietal operculum. “13. The fissure of Rolando is clearly the proper boundary of the frontal lobe. Above, it is separated only from the calloso-marginal fissure, which bounds the lobe internally, by a narrow but superficial gyrus; below, the inferior transverse furrow of Erbstaller acts as an inter- mediate link between it and the sulcus centralis insule. The sulcus centralis insule and the calloso-marginal - sulcus are brought into close relationship at the anterior perforated spot on the base of the brain. An almost continuous fissural system, therefore, marks out the lim- its of the frontal portion of the cerebrum. “14. The temporal pole is formed entirely by the for- ward growth of the fore part of the temporal operculum. “15. In the adult brain the insula is proportionately longer in the male than in the female. At all periods of growth it would seem that the insula is relatively longer on the left side. than on the right side. In the negro brain it would appear that the insula.is relatively shorter than in the European brain. “16. In the anthropoid ape the so-called anterior limb of the Sylvian fissure is not homologous with either of the anterior limbs in man. “17. In the chimpanzee and orang there are only two opercula, viz., the fronto-parietal and the temporal. The frontal and orbital opercula of the human brain are entirely absent in the anthropoid cerebrum. “18. Restricting the term insula to that part of the hemisphere surface which is concealed from view by opercula, the extent of this area in the ape is very much less than in man. The central index is 18.2 in the chim- panzee and 21.5 in the orang; in man the central -index is 29.6. In the lower apes the central index is higher than in the anthropoids. “19. In man the field of the insula shows marked REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, changes with reference to the cranial wall during intra- uterine life. More and more of its area comes to lie under cover of the parietal bone, and relatively less under cover of the frontal bone, as development pro- ceeds. In the aduit the coronal line cuts the insula in such a manner that thirteen per cent. of its length lies in front of it and eighty-seven per cent. behind it. “20. In the chimpanzee and the low apes no part of the insula lies in front of the coronal line; in the orang the upper and anterior corner of the insula projects slightly in front of this line. “21. In the human infant and young child, as well as in the ape, the point at which the stem of the Sylvian fissure reaches the outer surface of the hemisphere is situated relatively farther back than in the human adult. “22. The Sylvian fissure is relatively longer in the left hemisphere than in the right, and in the ape than in AO.) “28. In the Cebus (Figs. 853 and 854) the Sylvian fissure lies above the level of the squamous suture; in the ma- caque, homadryas, and orang, it lies immediately sub- jacent to the fore part of the suture; in Cynocephalus anubis and the chimpanzee the fissure is situated in its fore part below the level of the front part of the suture. “29. The relative depth of the parietal and temporal lobes in the lower apes resembles that in the human child; in the anthropoid ape the relative parietal depth of the hemisphere exceeds that in the human adult.” The Fissure of Rolando.—Cunningham found that in sixty per cent. of the brains examined the upper end of Fig. 852.—Left Cerebral Hemisphere of a Chacma Baboon. p, Various parts of the intraparietal system of furrows ; p1, sulcus postcentralis inferior ; p?, two parts of the sulcus postcentralis superior ; %, ra- mus horizontalis; i.p., sulcus postcentralis transversus ; 0, occipital operculum. the fissure of Rolando turned over the mesal border of the hemisphere; in nineteen per cent. its ventral end was connected by a shallow transverse sulcus with the Syl- vian fissure. The fissure of Rolando appears in two parts; the lower two-thirds appears before, and inde- pendently of, the upper third. The relative position of the fissure of Rolando is remarkably constant. The upper fronto-Rolandic index is 53.8, the lower 43.3. In anthropoids the upper end of the fissure of Rolando is placed relatively farther back than inman. The aver- age Rolandic angle in the human brain is 71.7. The average relative length of the fissure of Rolando is 39.3. The Intraparietal Suleus.—“1. The entire sulcus, single and continuous in some of the lower apes (e.g., Cebus), becomes broken up in the human brain into a group of furrows which present different relations to each other in different cases. “2. Three of the elements of the sulcus in the human brain, viz., the sulcus postcentralis inferior, the ramus horizontalis, and the ramus occipitalis, are disrupted portions of the original fissure; one, the sulcus postcen- tralis superior, is a superadded element (Fig. 859). “3. In the development of the sulcus in the human foetal brain, all the four segments of the sulcus have, as a rule, an independent origin, although, as Pansch has shown, the sulcus postcentralis inferior and the sulcus horizontalis very frequently appear as one continuous furrow. “4. The sulcus postcentralis inferior usually appears first; then the ramus horizontalis and ramus occipitalis; and last of all the sulcus postcentralis superior. “5. In Cebus there is no sulcus postcentralis superior; it is present, however, in most of the old-world apes, é.g., the baboon, macaque, gibbon, chimpanzee, orang, and gorilla (Fig. 858). “6. In the chimpanzee and orang there is reason to be- lieve that this segment of the postcentral sulcus consists of two elements, one placed above the other (Figs. 856 and 857). “7. Eberstaller’s third and lower segment of the post- central sulcus (viz., the sul- cus postcentralis transversus) is not only present in man, © but also in the majority of the old-world apes. “8. In the apes the intra- parietal sulcus is deeper than the fissure of Rolando; the opposite is the case in man. This would seem to indi- cate that the morphological value of the sulci is different in man and the apes. The phylogeny and ontogeny of these furrows are in apparent variance with each other. Fic. 853.—Cerebrum of Cebus Albifrons. f, Sulcus frontalis inferior ; ~.c., sulcus postcen- tralis inferior; 7, fissure of Rolando ; s, Sylvian fissure ; p, intraparietal sulcus; 3, ra- mus horizontalis; p*, ramus occipitalis ; st, furrow corre- sponding to sulcus transversus occipitalis of Ecker; p.0., pa- rieto-occipital fissure; an., first annectant gyrus; a.f., ape cleft. The fissure of Rolando appears first on the develop- ing cerebrum of the human fcetus, yet it is the intra- parietal sulcus which first makes its appearance in the evolution of the primate cerebrum... . “11. In man there appears to be a general tendency toward a union of the two originally distinct postcentral elements of the sulcus, and a divorce from the lower of those of the ramus horizontalis. ... “13. The ramus oc- cipitalis was connected with the ramus hori- > zontalis in 63.7 per cent. of the adult hu- man hemispheres ex- amined. “14, The union be- tween these two ele- ments of the sulcus, as Ecker and Wilder have shown, is much more common on the left side than on the right. “The sulcus transversus of Ecker is not the homologue of the ‘ Affenspalte’ in the apes, but merely a terminal bifurcation of the ramus occipitalis.” The Sulcus Precentralis.—“1. The sulcus precentralis inferior in the human brain is composed of a vertical and a horizon- tallimb. The latter is carried forward into the middle of the front- al convolution. “2. This furrow is the earliest to appear on the outer surface of the frontal lobe of the foetal brain. In some cases it is seen in the fifth- month cerebrum in the form of a long, deep, vertical sulcus, which subsequently undergoes a retrograde development before its adult condition is reached. In many cases, in its early condition, it pre- sents a form in every respect comparable with that ob- ; oT Fig. 854.—The Outer Surface of the Cerebrum of Cebus Albifrons. 1, Fis- sure of Rolando; p.c.i., sulcus pre- centralis inferior ; h, ramus horizon- talis; /?, inferior frontal sulcus. Fie. 855.—Another View of the Same. p.c.s., Sulcus preecentralis inferior (?) ; €.0., a Slight trace of the sulcus fronto- orbitalis. Other letters as in Fig. 854. Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. served in the cerebrum of the low ape (Cebus). Fre- quently it is developed in several pieces. “3. The sulcus precentralis superior is closely con- nected with the basal part of the first frontal furrow. It is usually developed along with it. It consists of two pieces—an upper and a lower—which may be partially or completely separated from each other, as well as from the basal part of the first frontal furrow by an annectant yrus. “4. Two additional furrows belonging to the precen- tral system are occasionally present, viz., the sulcus precentralis medius and the sulcus preecentralis margi- nalis. “5. The sulcus preecentralis medius may arise in two different ways: (a) It may be formed by the ramus hori- zontalis of the inferior precentral sulcus divorced from the vertical stem and assuming a very oblique or an al- most vertical position; (>) it may consist of a new ele- ment placed between the superior and inferior precen- tral furrows, but showing a closer connection with the LOMMET ea “12. The superior frontal gyrus and the middle frontal gyrus are each partially sub- divided into two tiers or sub- divisions by furrows which may be respectively termed the sulcus frontalis mesialis and the sulcus frontalis me- dius. “13. Both of these furrows “28. About the seventh month of feetal life the in- ferior precentral sulcus of the human brain attains a position which it retains unaltered throughout all the subsequent changes of growth; previous to this it is placed relatively farther back on the surface of the hemi- sphere. “29. At first it is placed in front of the coronal suture. The sutural line, however, moves forward so that the sulcus ultimately comes to lie behind it. “30. In the ape cerebrum the inferior precentral sulcus lies relatively much farther forward than in the cerebrum of man. It may be placed subjacent to, or in front of, the coronal line.” The Hippocampus. — The median part of the mantle, that portion which adjoins the opposite hemisphere and the thalamus, is very early separated from the rest of the cortex by a total fissure con- sisting of the hippocampal Fic. 857.—Right Hemisphere of a Male Orang, Six Years Old. fissure, the fissura calcarina, and ‘the (temporary) fissura parieto-occipitalis. The por- tion so separated is the gyrus r, Fissure of Rolando; 1, sul- cus postcentralis inferior; »?, two parts of. sulcus postcen- tralis superior; p°, ramus horizontalis; ~*, ramus oc- Fig. 856.—Cerebral Hemisphere of Young Female Chimpanzee, as seen from above. The oper- culum on each side has been removed. 7, Fissure of Ro- lando; p!, sulcus postcentralis inferior; p?, two portions of sulcus postcentralis superior ; p, ramus horizontalis; p4, ramus occipitalis ; b, terminal bifurcation of the intraparie- tal sulcus ; p.0., parieto-occip- ital fissure; a.7., first parieto- occipital annectant gyrus; a, deep annectant gyrus in the course of the intraparietal sul- cus; €, secondary sulcus in the superior parietal lobule ; a.f., bottom of the ‘ape-cleft”’; 0, cut surface of occipital oper- culum ; t?, parallel sulcus. have secured a firm footing in the human brain, but only one (viz., the frontalis me- dius) has established itself upon the brain of the chim- panzee (Fig. 856). . . . “17. The sulcus frontalis mesialis is absent or poorly developed in the brain of the NESTON ees “20. The sulcus preecen- tralis inferior and the inferior frontal sulcus are the fur- rows which are most firmly impressed upon the brain of theapes. In Cebus they alone are present; in Calithrix there are also traces of the sulcus preecentralis superior and sul- cus fronto-orbitalis; in the baboon there are, in addition, a rudimentary sulcus fron- talis superior, and perhaps (?) traces of a sulcus frontalis medius (Figs. 852 and 8538). “21. Inthe chimpanzee and the gorilla the sulcus frontalis medius is often present in a form precisely similar to that seen in the human brain; in the orang the condition of this sulcus is doubtful; in the gibbon the sulcus frontalis medius is absent. “22. In the chimpanzee, therefore, the same convolu- tion ties may be seen as in man, with this exception: the superior frontalis is never split into two by a sulcus frontalis mesialis. “23. The inferior fronta] convolution of apes is very different from that in man. “24 The frontal and orbital Sylvian opercula are completely absent in the apes. “25. Consequently, a portion of the island of Reil is uncovered and exposed on the surface of the cerebrum. “26. The sulcus fronto-orbitalis of apes corresponds to the anterior limiting sulcus of the island of Reil in man. “27. There are no anterior limbs of the Sylvian fissure in the anthropoid apes. The so-called anterior limb of the Sylvian fissure corresponds to the anterior free border of the fronto-parietal operculum. 278 cipitalis; a.n., first parieto- occipital annectant gyrus; _p.0., parieto-occipital fissure ; a.f., bottom of *“‘ape-cleft’’; o, cut surface of occipital operculum ; 8s, fissure of Syl- vius; t}, parallel sulcus. marginalis, and from it there develops caudally the curi- ous structure known as the hippocampus or Ammons- horn. The hippocampus is enrolled like a scroll and its mesal margin is rolled by an inverse curve into the space left by the loosely rolled fornicate portion. This portion of the cortex has been shown to be related to the function of smell, and to it are traced various bundles from the olfactory tuber. From it aiso rise fibres which cross in the hippocampal commissure or decussate in the fornix LLY ees a Fig. 858.—Right Cerebral Hemisphere of a Male Orangoutang, Six Years Old. f1, Sulcus frontalis superior ; £2, sulcus frontalis infe- rior ; f.m., sulcus frontalis medius ; ¢.0., sulcus fronto-orbitalis ; p.c., sulcus preecentralis inferior; p.c.s., sulcus preecentralis superior ; p.c.i., Sulcus przecentralis inferior ; 7, fissure of Rolando ; 1, suleus postcentralis inferior ; p?, sulcus postcentralis superior ; 3, sulcus horizontalis intraparietalis ; ¢.c., external calcarine fissure ; t1, par- allel sulcus; t?, second temporal suleus; H1, H?, H8, transverse temporal gyri of Heschl; R, insula; A}, first annectant gyrus; S?, anterior free border of the fronto-parietal operculum ; O, anterior edge of the occipital operculum. body and thence descend by the columns of the fornix to the thalamus. Some of the fibres pass to the tuber cinereum and enter the mammillary bodies. The Olfactory Region.—From a part of the hemispheres near the cephalic end of the gyrus marginalis, in lower REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain. Brain, animals at the cephalic extremity of the brain, while in higher mammals the point is. ventrally folded, there arises a protuberance called the olfactory lobe. Still cephalad the ventricle is produced to form a dilatation of the wall—the olfactory tuber. The actual means by which the tuber is formed may be discovered by watch- ing the early stages of development. At a very early period the front of the hemispheres comes into actual ¥iac. 859.—Outer Surface of a Cerebral Hemispheve in the Early Part of the Seventh Month. t}, Parallel sulcus; .c.i., inferior frontal; f1, sulcus frontalis primus; .c.s., sulcus preecentralis superior ; 1, fis- sure of Rolando; p, intraparietal sulcus; p1, sulcus postcentralis inferior ; p*, ramus horizontalis of the intraparietal sulcus; 4, ra- mus occipitalis ; e.p., fissura perpendicularis externa. contact with the depressions of the skin forming the olfactory fossa (Figs. 863 and 864). In this fossa there de- velop the ganglion cells of the olfactory from the proximal end of which the olfactory fibres make their way into the hemispheres. In this way the hemispheres are connected reer Fig. 860.—Horizontal Section of Guinea-Pig Head. Dc., Diacele; St., striatum; Aw., aula; L.t., lamina terminalis; P., plexus; H., bip- pocampus; a. and p., proliferating areas; 2., inner capsule. with the epithelium and the connection is retained from this time on. In some cases, as in certain fishes, the growth of the head causes the brain to be withdrawn a long dis- tance from the olfactory fosse, and the tuber is drawn out into an almost thread-like stalk which has often been mistaken for the olfactory nerve. In other cases the tuber has refused to be separated from the brain, and the frbres connecting with the olfactory epithelium have been extended and have been usually called the olfactory nerve, though here again incorrectly, for in a strict sense there is no olfactory nerve and this bundle should be called the root. In the tuber two portions can be dis- tinguished, the unaltered protrusion of the brain called the pes, and a slipper-like enlargement covering the pes, called the pero. Inthe latter isdeveloped what is known as the glomerule zone, in which the final branches of the olfactory root fibres mingle with the arborizations of the Fic. 861.—Two Horizontal Sections of Brain of Young Opossum, to Show Hippocampus and Fimbria. special mitral cells of the pero. Fibres from the latter pass backward to the region of the hippocampus. The Diencephaion and Mesencephalon—The external characters of the thalamus have already been mentioned in sufficient detail. Within there develop a number of clusters of cells which are better known in lower animals than in man, but in all cases the exact function remains problematical. It seems certain that the several tracts from organs of special sense here find rendezvous and from these temporary stations extend to the cortical areas. From the cerebellum fibres enter the nucleus ruber. From the geniculate nuclei the optic radiations Fig. 862.—Hinder Portion of Cerebral Hemisphere of Full-Term Foetus, Showing Conditions Approximating to Those of Anthropoid Apes. 1, Upper end of fissure of Rolando ; ¢.m., calloso-marginal sulcus ; p.0., parieto-occipital fissure ; cuwn., cuneus ; ¢, gyrus cunei; p.c., praecu- neus; g.f., gyrus fornicatus ; ¢.c., callosum ; c.f, collateral fissure ; OC, posterior secondary calcarine fissure; S, “stem” of calcarine fissure. pass to the occipital cortex. The rapid growth of the roof of the mesencephalon, as well as the curvature of the base due to the midbrain flexure, tends to fill the mid- brain vesicle, and in mammals the narrow iter alone re- 279 Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. mains. The basal or pes portion develops the several centres for visual co-ordination, while the dorsal longi- tudinal fasciculus lies immediately beneath the iter. Ventrally the fibres passing in both directions connecting the prosencephalon with the medulla oblongata form a thick mass on the ex- ternal aspect of the pes, called the crusta, through which the fibres of the third nerve find exit. Fig. 864.—Epithelium of Olfactory Pitin Prolif- eration. Fig. 863.—Section through Head of Gar- ter-Snake Embryo. a, Midbrain; b, olfactory pit; c, infundibulum. The Medulla Oblongata and the Cerebellum.—Reference has already been made to the relation of the cerebellum to the medulla, and also to the fact that this massive organ is built up partly from proliferations from the lateral walls of the fourth ventricle and partly from the concrescence of masses proliferated at the cephalic margin of the tela. In some mammals, at least, the writer has described a process of actual eversion of a sac from the lateral walls of the fourth ventricle in the region of the future cornucopia to give rise to superficial proliferating areas to supply Figs. 865 AND 866.—Horizontal Sections through the Head of Embryo Guinea-Pig. 860 from the same series farther dorsad.) Fig. 865 passes through the level of the eyes and infundib- ulum. The extension of the ventricle of the optic recess into the stalks of the optic nerves is shown at O.r. the cornucopiz is shown; Fs., frontal sinuses. 280 G.g., Gasser’s ganglion; L., lens; Op.l., optic lobes, roof of mesencephalon ; r.l., lateral recess of fourth ventricle extending upward within a fold of the rhomboidal lip to cover the lateral aspects of the cerebellum, as atx. Fig. 866 passes at a somewhat lower level, and shows the extension of the lateral recess near the tip of the cerebellum. At L.r. the beginning of the surface when cut off from the direct replenishment from the ventricles by the intrusion of the white matter. (Of. Figs. 865-868.) In an entirely similar way Professor Fig. 867.—Transverse Section of the Medulla and Cerebellum of Mouse Embryo. P.z., Superficial proliferating zone derived from the epi- thelium of everted lateral recess; L.r., lateral recess; Pl., plexus; c., cornucopia; VITI., root of eighth nerve; IV., fourth ventricle. His explains the origin of the olives by the eversion of the walls of the fourth ventricle at a lower level and the final envelopment of the proliferating epithelium in the parietes of the medulla. The margin of the cellular portion of the roof of the fourth ventricle constitutes the rhomboidal lip (“ Rauten- lippe” of His), which has been shown by many independent observers to have a most important function as a pro- liferating organ for both the medulla and the cerebellum. In man there is a greater development of nervous matter in the roof of the fourth ventricle and the walls of the lateral recess than in lower mammals. In all mammals there is a caudal as well as two lateral protru- sions of the membranous walls (tela). The lateral pro- trusions form the lateral recesses just mentioned, while the caudal projection in man becomes perforate, forming the foramen of Magendie or metapore. This pore is char- acteristic of anthropoids, but is absent in lower mammals. Even as early as the end of the third week the forebrain ‘forms almost a right angle with the medulla, and during the fourth and fifth weeks the pons flexure increases till the base of the mesencepha- lon is separated from that of the medulla only by the narrow and deep “saddle cleft.” From the dorsal ex- tremity of this cleft arises the fossa Tarini. The pons flex- ure gives opportunity for the development of the cerebel- lum by providing a place for it. The flexure finds recipro- cal expression in the choroid fold or inward loop of the tela. The cerebellum is divided into a median vermis, and, on either side, a pileum, para- flocculus, and flocculus. The regions which form the pilea are first developed and the vermis is last toappear. The first sulci also appear on the lateral parts and not on the (Compare also Fig. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, vermis. At about the middle of the third month four or five transverse convolutions appear on the vermis. By the fifth month the definitive form of the cerebellum is clearly defined. By this time the prepeduncles con- nect with the midbrain, and the valvula is formed by the Fig. 868.—Portion of Similar Section to Show the Double Proliferating Zone with Fibre Layer Between, at a, b, c. thinning of the dorsal walls cephalad of the vermis. As early as the third month the restiform bodies connect with the lateral lobes to form the postpedunculi. In the fourth month the medipedunculus and pons become obvious. : The formation of the pons by the decussating fibres of the medipeduncle of the cerebellum greatly modifies the cephalic part of the organ and leaves an isthmus region between the cephalic border of the pons and the mesen- cephalon which otherwise would perhaps hardly rise to the value of a recognized portion of the brain. At different levels in the medulla the sensory and the motor bundles connecting the cord with the upper parts of the brain decussate, and by this means the simplicity of structure seen in the cord is entirely destroyed in the myelencephalon. Added to this is the remarkable dif- ferentiation of the centres of the several cranial nerves (q. v.), Which also obscures the original uniformity of arrangement. The effect of the increased emphasis laid upon a particular sense is well illustrated in fishes, in which, for example, huge excrescences arise on the me- dulla in the region of one or other of the cranial roots, almost equal to the cerebellum in size. Several authors have observed even in human brains serially arranged eminences in the floor of the fourth ventricle, but whether they indicate neuromeres in the ) sense in which that term is now used in morphology, and what their fate may be in the adult, remain points of dis- pute. At the end of the second month there may be recognized in sections of the medulla four somewhat dis- tinct regions: (1) the region of the motor nuclei; (2) the substantia reticularis; (8) the region of the lateral nuclei and the substantia gelatinosa, and (4) the region of the olives. To these in later stages are added a vast number of tracts and scattered nuclei which may best be studied in the adult brain. The various regions of the brain developed in the manner above described have been given a great variety of names, and there has as yet been no general agreement as to the connotation of many names in common use. The system proposed by Professor His is given below because of its completeness, though it will require to be modified in detail to adapt it to more general usage. ne pele oblongata, Myelencephalon I. ) Bhouben: ) 1. Fons , | .e \ II. Cerebellum t Metencephalon II. f gE III. Isthmus rhombencephali ITI. J a sats IV,. Pedunculi cerebri IV. Corpora quadrigemina + fesencephalon IV. V,. Pars mammillaris hypothalami } Enceph- Ve. Thalamus ] haan | Dienceph- f Vs. Metathalamus he Pate alon V. V,. Epithalamus eat VI,. Pars optica hypothalami ee td ee | Heri 3» Rhinencephalon peta VIy. Pallium : ( spheerium J Prosen- | cephalon Telenceph- alon VI. The term epencepahalon is often applied to the cere- bellum, but, in spite of its great size in man, it is only an extension of the lateral walls of the medulla. It has been proposed to use oblongata as the brief substitute for the full form, “medulla oblongata,” but the substan- tive seems the more natural part of the binomial, as the objection that medulla is ambiguous is of no practical moment. Prosencephalon has been generally used as synonymous with telencephalon as applied by His, and by using met- encephalon instead of rhombencephalon we have a series of terms, founded on a sound embryological basis, which may be considered correlative and which are easily ap- plied, viz., meten-, mesen-, dien-, and prosen-cephalon. Closely related to the prenatal changes above described are their postnatal consequences. There is no sharp line to be drawn between the phenomena of growth before birth and those which continue in after life. Changes in proportion during the adolescent period affect the relation between head and body and between brain and the re- mainder of the central nervous system. Brain develop- ment proceeds in advance of that of the body at large, though in cases of defective development of the brain the body may attain a considerable degree of perfection, as has been shown by Lenowa. In a feetus of twenty-one weeks, according to Bischoff, the percentage weight of the brain to body is 18.5, in new-born male children 15.8, in new-born female children 12.2, at sixteen years of age the percentage is 3.9, inadult males it is 1.9, and in adult females 2.1. At birth the weight is nearly alike in the two sexes, but the absolute weight is, of course, influenced by the size of the body. During the first year, and to a somewhat less extent for the three following years, the Fic. 869.—Longitudinal Section of Cerebellum of Early Mouse Em- bryo. Mes., Mesocele or iter; V., valvula; R.l., rhomboidal lip, and proliferating area derived from it; Pl., plexus; Ch.f., choroid- eal fold; IV., fourth ventricle: Med., medulla base. growth is very rapid. By the seventh year the enceph- alon has nearly attained its full weight. Afterabout the fiftieth year a gradual loss of weight becomes apparent. The continuous and unequal demands made upon vari- ous parts of the brain operate to stimulate growth, waste, and repair to an unequal degree in different parts. In this connection it is important to note that there are laid 281 Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. up in store in certain parts of the brain nascent or latent cells (granules) which may interpolate themselves among the depleted cells of older growth. Education in its broadest sense includes all changes in the brain due to reactions of the organ upon afferent stimuli.. It is usual to state that all the elements (cells, etc.) of the brain are preformed in it at birth. If this were so, then education would consist in the progressive modification of these cclls and the perfection of a wide range of intercommunications between them. Leaving out of the account the possibility of the proliferation of new cells from a germinative epithelium, there can be no doubt that the latent cells above mentioned are called into activity by exercise, and increased brain power and a more extended range of activity are thereby secured. It would apparently follow that activity of mind would hasten the period of senility and brain decline; but as the reverse is the case, it may be assumed that proliferation or an analogous process really takes place. C. L. Herrick. BRAIN DISEASES: DIAGNOSIS OF LOCAL LE- SIONS.—Hisrory.—Although it was known in the first century that each hemisphere of the brain is in func- tional relation with the opposite half of the body, the facts upon which the prevailing theory of the localiza- tion of different functions in separate parts is based were not discovered until 1822. At that time Thomas Hood, in England, and Bouillaud, in France, noticed that dis- turbances of speech were caused by disease in the frontal lobes of the brain. M. Dax (1836) was the first to limit the area governing speech to the left frontal lobe, and Broca (1861) located it more exactly in the left third frontal convolution. The discussion of aphasia in the Academy of Medicine in Paris in 1864 awakened general interest and led to further investigation. Until that time scientific men, rejecting the unwarrantable conclusions of Gall and the phrenologists, had believed the teachings of Flourens, that the brain acts as a whole, its various parts not possessing various powers. The pathological evidence against this position collected by Broca, and strengthened during 1864-67 by facts observed by Hugh- lings Jackson and Meynert, received confirmation in 1870 from a new series of physiological experiments made by Fritsch and Hitzig in Berlin. These investigators found that in animals the anterior portion of the convexity of the brain is métor; that its irritation by electricity causes coordinated motions in the limbs of the opposite side, and that its destruction causes paralysis. Ferrier (1873- 76), Nothnagel (1877), Munk (1881), and Luciani (1884) have confirmed these results, and have shown further that the posterior portion of the convexity is sensory, its destruction being attended by impairment of the powers of perception through the various senses. Goltz, though opposing a strict limitation of functions to definite re- gions, admits that the results of destruction of various parts are different, and he has noticed that extensive in- jury to the anterior portion changes the character of an animal from kind to vicious, while injury to the posterior portion has the opposite effect. The conclusions of phys- iologists differ regarding the results of experiments, but do not overthrow the theory of localization as applied to man; for a mass of pathological evidence has been col- lected during the past ten years which will bear but one interpretation. Charcot and his pupils in France, Noth- nagel, Exner, and Wernicke in Germany, H. Jackson and Ferrier in England, and others, have gathered, classified, and analyzed a very large number of cases of brain dis- ease of limited extent, which were accompanied by defi- nite symptoms, and have established a causal relation between lesions of certain portions of the brain and dis- turbances of certain functions, both motor and sensory. It has also been discovered that deficient development of an organ is accompanied by deficient development of that part of the brain which is in functional relation with that organ, and vice versa (von Gudden). Further, the researches of Flechsig (1877-84) have proven that an anatomical connection exists between cer- 282 tain organs and certain parts of the brain by means of tracts, which can be distinguished from one another by peculiarities in the time and process of their development. To these same tracts are limited the secondary changes which ensue when the active organ at one extremity of the tract is destroyed. All these various kinds of evidence combine to establish the conclusion that definite parts of the brain possess distinct functions, and although there remain numerous functions whose location is unknown, and many parts of the brain whose function is undetermined, a sufficient number of facts is available to warrant in many cases of cerebral disease a localization of the lesion. GENERAL CONSIDERATIONS.—Since the different parts of the brain preside over different functions, the symp- toms present in any lesion will depend as much upon its situation as upon its nature. Certain general symptoms, such as headache, vertigo, convulsions, coma, or optic neuritis, occur in many forms of disease, and being indi- cations of disturbances of nutrition, or of increased intra- cranial pressure, do not indicate the position of the dis- ease. Other symptoms, however, such as disturbances of motion, of sensation, of sensory perception, of memory, or of speech, are known as local symptoms, since each is present only when a certain part of the brain is involved. It is from these that the localization of a lesion can be determined. Local symptoms must, however, be inter- preted with caution, and the direct effect of the lesion must be distinguished from its indirect effect. For ex- ample, immediately after a cerebral hemorrhage, attended with headache, vertigo, or coma, and possibly general convulsions and vomiting, the local symptoms of hemi- plegia, hemianzesthesia, and aphasia may be present, and may lead to the suspicion of a very extensive lesion. After a few days, however, there may remain only a partial hemiplegia, all other symptoms having subsided. In such a case the hemiplegia is the only direct local symptom; the indirect local symptoms—aphasia and hemianzesthesia—being incidental to the pressure on, or to disturbance of, circulation in parts adjacent to the actual seat of disease. It is only when a lesion is single, its effects stationary and of some duration, that a diagno- sis of its position is to be made. In diagnosticating the position of a lesion it is necessary to distinguish disease in the cortex from disease within the hemisphere. The functions of these parts are differ- ent. The gray cortex receives and initiates impulses. The white: matter within the hemisphere transmits the impulses. The impulses sent along white tracts to the cortex become conscious perceptions only when they reach their destination in the gray matter. Theimpulses passing along the white tracts from the cortex have been started in the gray matter as conscious volitions by effort. Thus sensation or motion may be suspended either by disease in the cortex or by disease in the tracts within the hemisphere. The cortex hasanother function. A sensa- tion once perceived, or a motion once acquired, leaves behind it a trace, whose nature is unknown, which shows itself in a disposition in the cells of the cortex to react more promptly to a similar impulse than to a dissimilar one. This is the physical basis of memory. Since simi- lar impulses always enter by the same sensory organ, and since each organ is connected with its own region of the cortex, it follows that the various memories are distrib-, uted in various regions. But these memories are often associated in consciousness, and this association is secured by means of white fibres which pass between and connect the various regions. It becomes evident, therefore, that diseases of memory may afford an important clue to the location of a lesion; and that the distinction between a disease of the gray cortex involving a loss of a certain kind of memory, and one of the white tracts within the hemisphere interfering with the proper association of ideas must not be overlooked. No part of the gray mat- ter can act vicariously for another part. Each tract con- veys its own impulses. Draenosis.—I. CoRTEX CEREBRI.—1. Lesions involv- ing the frontal lobes upon the base may destroy the olfac- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, tory bulb or tract and produce anosmia on the side of the lesion. Lesions in the other convolutions of the frontal lobes, excepting those in the posterior part of the third convolution of the left side, present no distinctive local symptoms. Some disturbance of mental action, mani- fested by an inability to concentrate the attention, to think connectedly, and to control the emotions, or even by a condition of imbegility, may be caused by disease in this region. These convolutions are often defective in idiots, and their comparative development in animals determines the mental power of the individual. But disease in this region in man does not cause a loss of any particular mental faculty, and for the higher powers of mind no location can be determined. Normal mental action im- plies the integrity of the entire brain. When general symptoms of cerebral disease are present, but no local symptoms can be found, the possibility of disease in the frontal convolutions is to be considered, and the occur- rence of the mental disturbance mentioned affords a pre- sumption in favor of this location. Lesions in the posterior part of the third frontal con- volution on the left side in right-handed, and on the right side in left-handed persons give rise to ataxic or motor Fic. 870.—Diagram of the Fissures and Convolutions of the Convexity of the Left Hemisphere of the Brain, with the areas presiding over various functions. ‘The speech areas are shown on this hemisphere. The motor area is more extensive on the left than on the right hemi- sphere. aphasia (Fig. 870). In this area are located the memo- ries of the combination of motor acts necessary to the pronunciation of words, memories which have been ac- quired by practice. If these memories are blotted out, the ability to initiate the impulse required to produce a given sound is lost, and speechlessness results. When this convolution alone is affected the patient can under- stand what is said to him, and may be able to write, but cannot talk (see Aphasia). 2. Lesions of the anterior and posterior central convo- lutions and of the paracentral lobule produce disturbances of motion (Fig. 870). The motor tracts which connect these convolutions of each hemisphere with the body decussate partially in the medulla, and the degree of the decussa- tion differs in different individuals. In the large major- ity of persons the tracts which cross to the opposite side are so much larger than those which go to the same side that the symptoms of cerebral disease are noticed only on the side of the body opposite to the side of the lesion. In all cases, however, except in those in which the decus- sation is complete (one in sixty), the side which is appar- ently normal is slightly affected. The disturbances of motion may be in the form of spasms and convulsions, or in the form of paralysis. Lesions irritating the motor region give rise to the former; those which destroy the cortex to the latter. The lower third of the anterior cen- tral convolution is in functional relation with the muscles of the face and tongue (Fig. 870). The middle third of both central convolutions governs the arm (Fig. 870), the motions of the shoulder, elbow, and hand lying from before backward and from above downward in the order named. The upper portion of both convolutions and the paracentral lobules contain the motor centres for the body and leg, the motions of the hip, knee, and foot lying from before backward and from above downward in the order named. The area related to the movement of the eyes is located by Landouzy and Exner in the inferior parietal lobule. As these areas for each part are distinct, cortical lesions of limited extent may affect one alone, or two adjacent areas; but it is only lesions of very great extent which can destroy them all. Monospasms, or monoplegia, are, therefore, prominent symptoms in dis- ease of the motor region. An irritation beginning in one area may extend to adjacent areas, in which case a con- vulsion may commence in one part and then involve other parts. The relative position of the areas, then, de- termines the order of progress of the convulsion, face, arm, and leg being successively affected, or vice versa ; and face and leg never being involved together without affection of the arm. When the entire side is involved the convulsion may become general. The seat of the initial irritation mav. therefore, be indicated by the order in which the spasms extend. After such a spasm there remains a paresis in the muscles affected, those last and least involved recovering first (see Hpilepsy). If the irri- tating lesion becomes a destroying lesion the monospasm is succeeded by monoplegia, and from the part of the body affected the area in the motor region which is de- stroyed can be determined. In cortical disease it is seldom that the lesion involves a single area without encroach- ing upon adjacent areas; hence, associated monoplegise of face and arm, or arm and leg, are more frequently met with than paralysis of one part alone. But even in these cases the disturbance of motion usually begins or is more marked in one part, rather than in both equally, and the order of extent of paralysis may indicate the direction in which the disease is progressing, and the place from which it started. In paralysis from cortical lesion there is a loss or marked impairment of the muscular sense, and there may be some disturbance of general sensation. pe 2 Ley & Z) ry . * “ay e sc Li ‘MOUTH AND 2 LARYNX Ay Fig. 895.—The Distribution of Motor Areas Over the External Surface of the Cerebral Hemi- (After Horsley and Schafer, from Barker.) spheres of the Monkey’s Brain. areas is removed, depends upon the extent of the lesion; if it is all removed the defect isa permanent one. In the monkey’s brain Munk obtained essentially the same re- sults. A summary of the results of Beevor, Horsley, and Schiifer (1887-1894) will serve best to indicate the pres- ent status of knowledge as to the exact representation of different movements over the Rolandic convolutions of the monkey and orangoutang, which stand nearest to man in biological relationship. The anterior central gyrus, they find, is much more concerned in the motor function than is the posterior central gyrus. They conclude that within the area of motor representation for the limbs, the regions for the larger joints are generally at the upper part of the area, while those of the smaller joints and more differentiated move- ments are at the lower part. Move- ments of extension are represented in the upper part, while those of flexion are in the lower. There ap- peared to be no absolute line separat- ing the area of one movement from that of another, each movement hav- ing a centre of maximal functional representation gradually shading off into the surrounding cortex. They distinguished a primary result of elec- trical stimulation from the subse- quent epileptoid march of the move- ments as the electrical stimulus became diffused through the cortex. Their general scheme of motor rep- resentation is diagrammatically sum- marized in Figs. 895 and 896. The results from ablations of areas of the cortex were quite in accord with their findings by the physiological method. Suggestive is the report that muscular movements of each in- dividual segment are much more fully represented in the cortex of the ourang than in that of the monkey. It seems a general law that the higher the animal the more definite is the area of representation not only of 304 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. individual segments, but of individual movements be- longing to one segment. This would suggest a still more specific motor representation in the human brain. The subdivisions of the motor area in man have been ascertained from a large number of carefully reported cases and autopsies, and from the electrical excitation of circumscribed areas of the cortex dur- ing its exposure for cerebral opera- tions. The exactness with which such localizations can be determined is remarkable. In 1888 Keen extir- pated the focal representation of the wrist in the right cerebral hemisphere which he had fixed in relation to the areas for the movements of the el- bows, shoulder, and face. After op- eration the left hand was found to be paralyzed as regards all move- ments of the fingers and wrist. The elbow was weak, but the shoulder and face were entirely unaffected. The distribution of specific motor areas over the cortex of the human cerebrum is presented in Figs. 897 and 898. The following summary is based upon those of Mills and Gor- dinier, omitting details which in some cases are still doubtful. As shown in the diagrams, the specific leg area occupies the upper third of the two Rolandic convolutions, the arm area the middle third, and the face area the lower third. The trunk muscles are repre- sented on the median surface of these two convolutions, the paracentral lobule. The leg area extends over the posterior part of the paracentral lobule and the upper anterior part of the superior parietal lobule; it occu- pies a greater antero-posterior surface than does the area of the arm or face. The movements of the thigh, knee, leg, foot, and toes are ranged in order from the front backward. The arm area is subdivided from above downward into centres for the movement of the shoulder, elbow, hand, and fingers. The move- Fig. 896.—The Distribution of Motor Areas Over the Median Surface of the Cerebral Hemi- spheres of the Monkey’s Brain. (After Horsley and Schafer, from Barker.) ments of the shoulder are also represented in. the an- terior part of the paracentral lobule. The subdivi- sions of the face area contain from above downward the movements of the orbicularis palpebrarum and oc- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. cipito-frontalis, the mouth, lips, tongue, pharynx, and larynx. The platysmal movements, according to Mills, are probably represented in the posterior part, and the larynx and pharynx in the anterior part. Movements of the head and eyes are probably represented in the posterior part of the first and second convolutions ad- Rinesthetic and General Somatic Sensation Kineesthetic iting ? Fic. 897.—The Distribution of Sensory and Association Areas Over the External Surface of the Cerebral Hemispheres. The diagram shows: 1, The area of kinesthetic and general somatic sensation, occupy- ing the central convolutions and portions of adjacent convolu- tions. (This is usually called the motor area. It is both an emissive or motor and a receptive or sensory area. The localization of the sub- divided sensorimotor areas is indicated in the diagram.) 2, the area of auditory sensation, occupying the middle portion of the superior conyolution and adjacent portions of the transverse convolutions of the temporal lobe; 3, the area of association of the first order, occu- pying the occipital lobe, the second and third temporal convolutions, a portion of the superior temporal convolution, the insula, and the posterior parietal convolutions ; 4, the area of association of the sec- ond order, or the zone of language, occupying the angular gyrus, the upper portion of the superior temporal convolution, the posterior third of the inferior frontal convolution (restricted to a single hemi- sphere, most frequently the left); 5, the area of association of the third order, the area of apperception, occupying the prefrontal re- , ions of the frontal lobes. jacent to the ascending frontal and on the median surface of the first frontal convolution. Those movements of the body which are always bilaterally innervated appear to have bilateral representation, so that an injury of one hemisphere, ¢.g., of the laryngeal centte, fails to produce paralysis. Those movements, on the other hand, which may take piace on one side of the body only, are repre- sented in the assigned area of the opposite hemisphere only. To Munk, in the opinion of the writer, belongs the credit of offering a satisfactory interpretation of the re- lation between the motor and sensory functions of the cortex and between psychical disturbance and the loss of simple sensation. From this point on, I shall merely sum- marize the views of different authorities with respect to various cortical functions, considering first in order the sensory areas, and next the areas of higher psychical ac- tivity. The excitable motor area is a “feeling sphere,” according to Munk, because it receives afferent stimula- tions which excite the cortical cells to give rise to sensa- tions and ideas of bodily movement. Cortical stimula- tion, otherwise than through the afferent tracts, may awaken memories or ideas of such movements. Fritsch .and Hitzig. had indeed referred to the Rolandic convolu- tions as the area of the muscular sense. For a long time, however, sensations of the muscle sense were understood to be due to the efferent stimulus of the cells in that region. This notion gave rise to the theory of an “in- nervation feeling” or “sense,” a theory which Wundt did not entirely give up until the appearance of the third edition of the “ Physiologische Psychologie” in 1887. It is now accepted that the activity of purely motor cells of efferent conduction in the Rolandic region (probably the large pyramidal cells) is unaccompanied by con- sciousness; that sensations or feelings of bodily movement are primarily due to the activity of sensory cells of the same region which receive stimulation from the sensory Vou. II1.—20 Brain, Brain, conduction paths comprising the median fillet and pos- terior columns of the cord. Bastian made the valuable proposition to call these areas “kinesthetic” areas or areas of “kineesthetic sensation.” Goltz’s results were in many ways contradictory of both Munk’s and Ferrier’s, but this contradiction is to a great extent limited to de- tails, and in the main his work is confirmatory of the trend of the results as indicated in this paper. Although he contended that it is not possible permanently to para- lyze any muscle, he distinguishes between fine and coarse adaptations, and shows that although a dog’s paw is not paralyzed as an organ of locomotion by the de- struction of the cortex, it yet remains permanently par- aheee for all those actions in which it is employed asa hand. The testimony of experimental physiologists, includ- ing in addition to those mentioned above Luciani, Hors- ley, and Mott, points unequivocally to the so-called motor area and immediately adjacent convolutions as the centre of kinesthetic sensation and of touch, pressure, heat, cold, and pain sensation as well. For this reason the convolutions of motor function are designated in Figs. 897 and 898 as areas of kinesthetic and general somatic sensation. Confirmatory are also the pathologi- cal findings of Gowers, Westphal, Seguin, Dana, and Starr. Dana’s twenty-five cases, four of his own with twenty-one others, all prove that lesions of the central convolution are attended by partial or complete loss of tactile, temperature, pain, and muscular senses in the limbs of the opposite side of the body. Starr, after thirty cases of cerebral operations consisting of excisions of parts of the motor area, thinks that it is clearly de- termined that the tactile centres are situated in the Ro- landic area, especially in the postcentral gyrus. Redlich, from an analysis of twenty cases of lesions confined to the parietal lobe, states positively that these lobes are the centres for muscle sense. Nothnagel, Luciani, Sep- pelli, and Flechsig long ago asserted that the parietal lobes were concerned in the reception of muscle sense impressions and possibly of the other forms of general sensation. Many pathologists whose opinions justly carry great weight are opponents of the view here repre- sented. Among these, Mills is most worthy of mention as still contending for the restrictedly motorial function of the excitable areas of the Rolandic convolution and K incesthetic and General Somatic Sensation Fig. 898.—The Distribution of Sensory and Association Areas Over the Median Surface of the Cerebral Hemispheres. The diagram presents: 1, The area of kingesthetic and general somatic sensation, occupying portions of the parietal and frontal lobes; 2, the areas of visual sensation in the convolutions adjacent to the calcarine fissure ; 8, the areas of olfactory and gustatory sensation in the uncinate gyrus and adjacent cortex; 4, the area of association of the third order, or area of apperception, in the prefrontal convolutions of the frontal lobes. The portions of the parietal and temporal lobes to which no special function is assigned in the diagram are association areas of the first order. for a distinct representation of cutaneous and muscular sensations in the adjacent postero-parietal convolutions, precuneus and gyrus fornicatus. In support of this view 305 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. he maintains that innumerable cases have been reported of lesions of the motor cortex without impairment of sensibility. He also cites his own experience with that of others which shows that surgical excision of the Ro- landic cortex is not necessarily followed by any sensory impairment. The results of histological investigation of the struc- tural elements of the cortex in the main confirm the view that the functions of the Rolandic cortex are only in part motor. At least four layers of the cortex are distin- guished—a superficial layer rich in small cells and tan- gential fibres, a layer of small and a layer of large pyram- idal cells, and a deeper layer of polygonal cells which are supposed to give rise to short and long associational neuraxones. Only the pyramidal cells, perhaps only the very large pyramidal cells, are supposed to give rise to the projection neuraxones of efferent or cortico-fugal conduction—7.e., those fibres which pass in groups func- tionally related through the internal capsule to the crura cerebri, to terminate about the motor cells of the cranial nerves of the same, but chiefly of the opposite side, or to continue on through the pyramids and, a portion crossed and a portion uncrossed, to terminate about the motor cells in the anterior horn of the cord, partly on the same and partly on the opposite side. The path of these pro- jection neurones has been made out by the stimulation methods of Beevor and Horsley, Burdon Sanderson, Franck, and Pitres, and by the studies of resultant de- generation, first initiated by Tiirck in 1851, and subse- quently extended by Bouchard, Charcot, Pierret, Noth- nagel, von Monakow, Marchi, Hoche. The excision of limited areas of the motor cortex gives rise to secondary de- generations also; these have been studied by von Gudden, von Monakow, Franck, Pitres, Moueli, Marchi, Algeri, Muratoff, Mellus and Langley, and Sherrington. The true motor cells are so situated that they may be stimulated to activity by the constituent cells of the proximate cor- tex, by associational and commissural neuraxones from remote parts of the cortex, or by the neuraxones of affer- ent conduction which terminate, perhaps, in all four lay- ers of the cortex. Cajal has presented a scheme of inter- cortical relation, and has constructed an elaborate theory of the neuronal mechanism of association, ideation, and attention. Problematic as this scheme remains, it indi- cates a new line of speculation as to cerebral functions, based on a discrimination of the various sensory, motor, and associational cells of a given part of the cortex, and promises much fora future better understanding of the specific psycho-physiological activities of the nervous system. Edinger from embryological researches, and von Mona- kow from the study of secondary degeneration, report that the sensory fibres of the fillet or lemniscus terminate in the cortex of the postcentral convolution and parietal lobe. The afferent neuraxone terminations in the Rolandic convolutions are in functional connection with the nuclei of the mid- and hind-brain, particularly with those path- ways of conduction which mediate common sensation. This area, therefore, is physiologically a sensory or recep- tive centre for cortico-petal stimuli of all sense tracts ex- cept the four sense tracts of special sensation, as well as the motor or emissive centre of the most important tracts of motor innervation. The most extensive experiments dealing with the sen- sory fibres leading to this part of the cortex are those of Flechsig. He divides these cortico-petal fibres—which pass together through the internal capsule and which are the indirect continuations of the dorsal roots of the cere- bral and spinal nerves—into three groups or systems, distinguished by the fact that they put on their myelin sheath at different periods. The first group becomes medullated at the beginning of the ninth foetal month. It occupies the posterior part of the internal capsule and, in its upper half, the area immediately behind the fibres of the pyramidal tract. These fibres are dis- tributed exclusively to the cortex of the two central gyri, which are thus the first regions of the cortex to become connected by means of medullated fibres with the sen- 306 sory apparatus of the body (see Figs. 900 and 901). The second group receives its myelin about a month later than the first group. These fibres are distributed to the central gyri, the lobulus paracentralis, and the foot of the superior frontal gyrus. Another portion is distributed to the gyrus fornicatus along its whole length. The posterior bundles run toward Ammon’s horn, and still another bundle enters into the uncus and arrives at the subiculum cornu Ammonis. The whole of the limbic lobe is thus connected with the lateral nucleus of the thalamus. The third system is also joined with the lat- eral nucleus of the thalamus and one part runs directly to the foot of the third convolution, another portion through the pars frontalis of the internal capsule into the frontal lobe almost as far as the pole, part of the fibres reaching the middle portion of the gyrus fornicatus, another part the anterior half of the superior frontal gyri, while single fibres go to the middle of the frontal gyri. Edinger and von Monakow also distinguish from the cortico-fugal pyramidal tract a fronto-cerebro-cortico-pontal tract. These fibres, according to Flechsig, arise in those regions of the cerebral cortex which correspond to the distribu- tion of the third group of sensory fibres, 7.¢., the feet of the three frontal gyri and possibly also the middle por- tion of the gyrus fornicatus. They terminate in the nuclei of the ponsand are concerned with the movements of bilaterally innervated muscles, such as those of the eyes, neck, and trunk. The motor impulses concerned in the speech movements may also, he believes, be carried by these fibres, though according to Barker there is a good deal of evidence that the speech path is separate and dis- tinct. Results indicating the cortical localization of the area of vision have from the first been consistent in prescrib- ing its limits to the occipital lobes and adjacent parieto- temporal convolutions. The location within these limits has been differently assigned; thus Hitzig to gyri in the posterior lobes of the dog, while Ferrier has persistently contended for the angular gyrus. Munk’s careful and critical investigations prepared the way for an undete standing of the relation of the different parts of the visual area. He distinguished between psychical blind- ness and the simple Joss of vision proper, and found different areas giving rise to these diverse conditions. He interpreted the area of simple or primary vision to be the cortical projection field of the retina, whereas ad- jacent areas added those memory images which made visual impressions intelligible. Despite conflicting evi- dence, it is fairly well established that the primary visual areas of the cerebral hemispheres are situated in the neighborhood of the cuneus, and that the calearine fissure bears about the same relation to visual stimulation as the Rolandic fissure does to somesthetic stimuli. This state- ment refers, however, only to retinal stimulations, which constitute in reality only a very smal] part of those sen- sory stimuli which are essential for the maintenance of complete vision. Henschen proposes for this area the name of calcarine retina, and suggests, from an examina- tion of clinico-pathological evidence, that the upper lip of the calcarine fissure of one hemisphere is the projection field of the lower quadrants of the visual fields of the homonymous halves of both retinee, and that the lower lip has a corresponding connection with the upper visual fields. Henschen also assigned the cortical representa- tion of the central portion of the retina to the anterior part of the calearine fissure and of the peripheral por- tions of the retina to the posterior part. The macula seems from many results to have a separate and distinct representation and to be represented for each eye in both cortices, whereas the symmetrical halves of each retina are represented in the hemisphere of the same side only. Cajal has shown that the fibres of the macula retained their individuality as far as the basal ganglia. It is de- nied, however, by von Monakow and others, that there is a distinct cortical area for the macula. He believes that it is represented in perhaps all portions of the occipital lobe constituting the visual area, even in the posterior part of the angular gyrus Examination of the results REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. of pathological findings indicates the possibility of much individual variation both at the centres and along the conduction pathways. There can be little doubt that the cuneus (see Fig. 898, page 305) is the cortical centre of primary visual sensation, and that regions which ontogen- ically acquire the associational capacity of complex visual perception involving the visual memories of past expe- rience, spread out over the convex surface of the occipi- tal lobes and perhaps to adjacent lobes, certainly to the angular gyrus (see Fig. 897). Kinzesthetic stim- uli from the muscles of the eyes are important elements in visual per- ception; whether these are conducted to the visual area also does not appear; it is probable, however, that sensations of eye movements are as- sociated in this area with the light sensations due to retinal stimulation. This conclusion seems the more necessary since, according to Ramon y Cajal, Engleman, von Monakow, von Gehuch- ten, K6élliker, and Held, the centrifugal fibres start in the axis-cylinder processes of the pyram- idal cells of the cortex and arborize in the su- perficial gray matter of the anterior corpora quadrigemina. Proc- cesses from these gan- glia terminate in the nervous feltwork of the retina and are in func- tional connection with the motor nuclei of the ocular and other nerves supplying the facial muscles. The connec- tion of the cortex with these subcortical ganglia suggests that the oculo- motor functions of the occipital lobe are exer- cised centrifugally via the optic radiation, as maintained by Munk and Sherrington (see Fig. 899). Thus through Pde these centrifugal neu- rones the retina, the oc- ular reflexes, and facial instinctive movements may be under the influ- “a fi f : “ai H AN: a @ FWA EP at H ‘i Nopticus. Moe Gatum faterate Optic radiations. _ Stratum pigmenti retine. $ é , -« Radiatio occipito-thalamica,. \\ Lobus occipitalis (cortex) Fourth layer. \ We Dendrazxone. ” \) Fig. 899.—Diagram of the Visual Conduction Paths. Barker.) a, b,c, Rods and cones of the retina; d, e, bipolar cells; f, large multipolar ganglion cells, giving rise toaxones of the optic nerve; g, centrif- ugal axone of a neurone, the cell body of which is situated in the anterior Brain, Brain, obstacles, etc., the retinal reflex of contraction of the pupils to light, and perhaps even of acquired visual re- flexes, such as the flight from a whip, etc. The expres- sion of the emotions of involuntary origin appears to have its origin in the thalamus. The loss of the emo- tional involuntary reflex, at all events, may follow upon a lesion of this subcortical ganglion. As in the case of cortical visual representation, the localization of the sense of audition has been restricted by almost all observers to a region of well-de- fined limits, in this case to the convolutions of the temporal lobe. Fer- rier’s results point to the superior temporo-sphe- noidal convolution on each side, because elec- trical excitation of this area on either side in- variably produced in the monkey retraction of the opposite ear associated with opening of the eyes and dilatation of the pupils; these movements Ferrier regarded as a significant index of au- ditory perception. Munk distinguished an area of greater intensity from adjacent regions of less intensity, both in N. oculo-motorius. the temporal lobes. Lu- ae ciani considers the audi- 5 tory sphere to extend g) over the whole cortical area of the temporal Rods and cones; Membrana limitans externa. External nuclear layer, External molecular layer. Internal nuclear lauers Internal molecular layer. Layer of ganglion cells. Layer of nerve fibres., ‘ae ‘Membrana limitans interna, Colliculus superior. , a lobe. Pathological evi- 5 ero dence has with equal de- ; 7 cisiveness pointed to the temporal lobe. Bastian, ‘Dendrazone. Wernicke, Friedliinder, Shaw, and Mills leave no room for doubt that the centres for hearing are situated in the superior temporal gyrus of each side. Each car seems to be represented in both lobes, as both superior temporal gyri in man must be destroyed in order that total deafness shall ensue. The re- searches of Flechsig, von Monakow, Held, von Kolliker, Ramon y Cajal, and Florence Sabin have shown the anatomical relations of the cochlear Third cortical layer (giant pyramidal cells). (After von Monakow, from ence of the occipital corpora quarigemina (colliculus superior), its terminal dendritic processes branch of the auditory cortex. Of the basal being situated in the retina; h, Golgi cell of type LJ, in the lateral geniculate nerve, Which alone is nuclei, 7.¢., thalamus, Lat Eee neurone connecting the paper ee Raia te the atl gee concerned in hearing . lobe, its axone running in the optic radiation of Gratiolet. The centripe . a pec treese 4 BES external geniculate ang centrifugal courses of the visual impulses are indicated by the arrows. with the various basal body, anterior corpora quadrigemina, connect- ed with the visual function, the external geniculate body alone seems to be in direct relation to retinal stim- uli. Lesion of this ganglion inevitably causes hemi- anopsia, and its destruction is followed by atrophy of the inferior portion of the bundle of Gratiolet. The pulvi- nar of the thalamus, on the other hand, may atrophy without producing hemianopsia if the geniculate body be intact. Lesion of the pulvinar and anterior corpora quadrigemina may, nevertheless, produce important modifications of vision. These ganglia appear to be centres of visual reflexes, such as winking, avoiding of nuclei, the chief of which are the trapezoid nu- cleus, the superior olive, the posterior corpora quadri- gemina, the median geniculate nucleus, and the nucleus lemnisci lateralis. The fibre tracts connecting these va- rious nuclei furnish an anatomical basis for more than one pathway of partial decussation. These fibres are also connected with the anterior corpora quadrigemina and with the motor nuclei of the cranial nerves, thus con- stituting a basal organ for automatic movements of the head, and perhaps of the trunk, in response to auditory stimulation. It is not deemed advisable to present the several parts of the complicated pathway of afferent 307 Brain. Brain, conduction, as these have been made out by various in- vestigators. It will suffice to mention that the collected fibres from these various nuclei pass as the lateral fillet, according to Flechsig in two separate bundles, to the internal capsule, and go transversely through the same in two separate bundles to the transverse gyri of the tem- poral lobe. The one bundle ascends near the external capsule and arrives from behind and above into the audi- tory sense area. The other runs for some distance along with the occipito-thalamic radiations, and passes around the fossa Sylvii from behind and below into the temporal lobe itself, close by the second and third temporal gyri, to reach the transverse temporal gyrus. The exact ex- tent of the sense region, according to Flechsig, corresponds to the two transverse gyri of the temporal lobe, particu- larly the anterior and that portion of the superior tem- poral immediately adjacent (see Figs. 900 and 901, on pages 308 and 309). ‘ The giant pyramidal cells, which are believed to give origin to the cortico-fugal projection tracts, seem to be absent in this region. Flechsig nevertheless maintains that the temporo-cortico-cerebro-pontal path begins here. The axones of this bundle of fibres, usually but mistakenly called Tiirck’s bundle, pass down, through the anterior portion of the occipital part of the internal capsule, to the lateral region of the base of the cerebral peduncles; thence they go into the pons, terminating perhaps in the nuclei of that region. Flechsig is inclined to think that this temporal path represents a mode of connection, by way of the brachium pontis, of one cerebral with the op- posite cerebellar hemisphere. The fibres are medullated at a later period than the fibres of the pyramidal tract; Von Monakow and Déjerine also report on this tract Déjerine believes, however, that the bundle arises from the whole temporal lobe, but chiefly the median and inferior convolutions. Whatever the origin, course, and termination of this tract may be, there can be little fia. 900.—The Sense Areas and Association Areas on the External Surface of the Right Cerebral (From Flechsig.) The closely dotted areas about the central fissure, on the middle part of the superior temporal convolution, and in the posterior part of the occipital lobe, indicate respectively the primary areas of general somatic sensation, of auditory and of visual sensation. The regions not marked with the dots are: 1, The posterior association areas in the parietal, occipital, and temporal lobes ; 2, the middle association area in the insula; 3, the anterior association As the thickly dotted regions shade off into the unmarked regions, so the primary sense areas are continued into adjacent portions of the association areas, presenting a Hemisphere. area in the frontal lobe. gradual transition from the simpler to the more complex functions. doubt as to its existence. The evidence seems to point to the middle part of the superior temporal convolution as the primary cortical auditory area (see Fig. 897, page 805), while the areas for more complex auditory percep- 308 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tions are located in the upper part of the second and third convolutions toward the angular gyrus, and perhaps ex- tend downward over the fourth and fifth temporal con- volutions also, a region in which Mills places a centre for the hearing of words—the so-called “naming” or “idea” centre. The vestibular branch of the auditory nerve is con- nected with nuclei which are in anatomical relation with the cerebellum and with the median fillet; thus stimuli from this branch may pass to the somesthetic area of the cerebral hemispheres. Ferrier located the sense of taste and smell in the sub- iculum and in neighboring portions of the lower temporal convolution. | Munk localized smell in the gyrus hippo- campus. According to Andriezen, the cortical regions which receive the olfactory projection fibres are (1) the region of the genu of the gyrus fornicatus; (2) the septum lucidum; (8) the inferior extremities of the hippocampal and uncinate gyri. Hill looks upon the fornix as one of the conduction paths, and this is certainly in accord with the relation of that structure to the terminal cortical areas just named. Cases have been reported by Ogle, Jack- son, Hamilton, Worcester, and others, in which impair- ment or loss of smell was associated with lesions of the gyrus uncinatus or its immediate vicinity. According to Flechsig, the olfactory conduction path in the fore- brain is the first path connected with the special sense organs to become medullated. Turner grouped the re- gions especially-connected with the sense of smell in 1865 under the term rhinencephalon. His and Edinger con- sider this separation of the parts concerned with smell to be in accord with the facts of embryological and phy- logenetical development. The rhinencephalon is rich in neurones connecting it with the basal ganglia; these lower centres are therefore so situated as to be able to re- spond reflexly or anatomically to all forms of general or special sensory stimulation. The gyrus hippocampus, especially the uncus, appears to be established as the corti- cal sensory area for olfactory stimulation. The _ cortical area for the sense of taste is probably located adjacent to the area for that of smell, per- haps occupying in part a por- tion of the fourth temporal convolution. Turner (1897) in reviewing the subject finds disagreement among investi- gators as to the peripheral gustatory neurones and al- most complete ignorance as to the central neurones. Bech- terew has presented a scheme of taste conduction paths. Peripherally these involve the fifth and ninth nerves in the region of the fourth ventricle, where with the motor nuclei of the fifth, seventh, and ninth nerves. The limited knowl- edge pointing to a definite location of taste sensation is in accord with the relative unimportance of this sensa- tion and with its close asso- ciation to the sensations of smell, of touch, and of tem- perature. The primary centres of sensation occupy only about one-third of the superficial surface of the cerebral hemi- spheres (see Figs. 897, 898, 900, and 901). These physi- ologically are higher sensorimotor centres superimposed upon the lower basal centres, and enable the organ- ism which possesses them to act in response to stimuli they are associated — REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, with more complicated coordination than would be pos- sible with the basal and other lower centres alone. In Figs. 900 and 901 the central portion of each sensory area is indicated by the more numerous dcts which rep- resent, according to Flechsig, their richer supply of cor- tico-petal fibres, while the less frequent dots represent the portion in which these fibres are less numerous. The remaining two-thirds of the cerebral area, unmarked with dots, are not provided with projection fibres either afferent or efferent. The white matter of all these cor- tical regions, with the excep- tion perhaps of that beneath the angular gyrus, becomes medullated considerably later than that of the sense cen- tres, so that even in children three months old the former are sharply distinguishable from the latter by their pov- erty of myelin. Flechsig finds, however, that medullat- ed paths gradually grow out from the sense centres into these non-medullated regions. : Further, between the individ- ual gyri of the non-medullat- ed regions, bands of associa- tion fibres gradually ripen, connecting the individual gyri with others near them and also with gyri at a dis- tance. These areas Flechsig designates association areas; through these alone one sensory area is indirectly con- nected with another. The association areas are there- fore centres whose cells are superimposed upon those of lower primary sensory areas, supplying a mechanism for the higher co-ordinations which are most representa- tive of the intelligent as well as of the conscious life of the organism. He designates as the posterior association area that part which includes the precuneus, all the parietal gyrus, except the postcentral gyrus, part of the gyrus lingualis, the fusiform gyrus, and the middle and inferior temporal gyrus, as well as all portions of the oc- cipital gyrus not concerned in the visual sense area. This association region is therefore situated midway be- tween the visual, the somesthetic, and the auditory sense areas, and is indeed not remote from the olfactory and gustatory areas. The middle association area is consti- tuted by the island of Reil, surrounded by the somes- thetic area, the auditory area, and the olfactory area, from all of which bands of fibres run into it. The prefrontal convolutions constitute the anterior association area, which is chiefly connected with the somesthetic area and the olfactory sense area. The facts advanced by Flechsig are admitted in part, but contested in part also. Thus von Monakow asserts that projection fibres go to nearly all parts of the cortex, _ though he, as well as all others, admits that some parts re- ceive fewer by far than others, the frontal lobe especially receiving few, if any. Some also deny that association tracts connect the sensory areas only indirectly through the association areas. These tracts have been made out in some instances with much precision. The polymorphous cells of the fourth layer and of the pyramidal layers are admitted to give origin to the fibres that either separately or as constituents of well-defined tracts unite in functional relationship the cortices of separated convolutions. By means of the corpus callosum the gyri in one hemi- sphere are connected with those in the opposite hemi- sphere. Of short association fibres there are five differ- ent bundles that have been made out in the occipital lobes sphere. in the frontal lobe. (From Flechsig.) alone. In the frontal lobes, fewer distinct bundles of association fibres have been made out, although Déjerine has described the source of several. In the temporal lobe and insula, similar bundles have been described but Fic. 901.—The Sense Areas and Association Areas on the Median Surface of the Left Cerebral Hemi- The closely dotted regions in the anterior portion of the parietal and posterior portion of the frontal lobes, about the calcarine fissure, and in the hippocampal and uncinate gyri, indicate respectively the primary sense areas of general somatic sensation, of visual sensation, and of gustatory and olfactory sensation. The posterior association area in the precuneus and temporal lobe; 2, the anterior association area The regions not marked with dots are: 1, no definite tracts have been ascertained. The long associa- tion tracts that have been described are, according to Bark- er: (1) the cingulum, which belongs to the rhinencepha- lon; (2) fasciculus longitudinalis superioris, connecting the frontal and occipital lobes; (8) fasciculus longitudi- nalis inferioris, uniting the occipital and temporal lobes; it is suggested that this may be the bundle connecting the visual sense area with the auditory sense area; (4) fasci- culus uncinatus, which extends between the uncus and the basal portion of the frontal lobe, and which may be an as- sociation tract of the rhinencephalon; (5) the tapetum, which is held by some to be a portion of the fasciculus longitudinalis superioris. According to Déjerine, it arises in the whole cortex of the frontal lobe, and, passing through the tapetum, its fibres are distributed to the lateral surface and inferior border of the lobus occipitalis. These results seem to establish a direct connection be- tween the various sense centres, as well as the indirect connection through the association areas as proposed by Flechsig. Whether Flechsig be right or wrong in this, whether subsequent research shall substantiate or dis- prove the anatomical connections and relationships in- dicated by the report of his results of the embryological method, it seems to the writer that Flechsig’s psycho- physiological interpretation of the functions of the asso- ciation areas isin the main incontestibly sound in psy- chology, and accordant with the trend of conclusions drawn from multifarious experimental and clinical in- vestigations. It has already been pointed out that most authorities distinguish between sensory disturbances and perceptual disturbances. Loss of memory and of higher sense per- ception have generally been attributed to regions which lie from the direction of the auditory, visual and somesthetic areas toward theangular gyrus. Itis immaterial whether psychical blindness, deafness, etc., are due to a loss of memory images or to an ataxia of sense perception. It seems clear that the nearer a lesion lies to the calcarine fissure, the Rolandic fissure, or the middle part of the 309 Brain, Brain, temporal convolution, the more likely is the injury to give rise to a loss of sensation only; and the nearer the injury is to the angular gyrus, the more likely is the re- sult to be a loss of perception, ideas, and memories con- nected with sensory impression. And yet it is difficult, both on the physiological and on the psychological side, to distinguish a pure sensation from one with an admix- ture of memory images. What a sensation would be utterly divorced from integral connection with the con- sciousness of the individual it is impossible to say. The association centres of Flechsig are centres of perceptual and ideational integration. Through their activity, in conjunction with the functions of the sensory areas, the actions of the human being are able to reflect the influ- ence of acquired individual experience. The posterior association centre (see Fig. 897, page 305, and Fig. 900, page 308) is concerned chiefly with the intel- lectual processes. Injury to the cells of this centre is followed by various forms of psychical blindness, by apraxia, agnosia, amnesia, and sometimes a weakening of the imagination. The anterior association centre is most closely associated in function with the someesthetic area, and hence also with the motor regions concerned in conduct, so that here in all probability is to be sought the anatomical mechanism by means of which the memory effects of all conscious bodily experiences, especially of acts of will, are retained. In injuries to this region, Flechsig maintains, interest in the external world is lost and the most marked alterations of character, at- tention, reflection, and inhibition are manifest. There may be symptoms of over-appreciation or of great self-depreciation; the speech may for a long time remain unaffected, but judgment as to what is right and wrong, beautiful and hateful, will be impaired, and there may be lack of self-command, even when uninfluenced by violent emotions, readiness to yield to sexual excitement, and finally imbecility. When the posterior association centres are mainly involved it is knowledge of the external world, rather than of his body and personality, that is impaired. Ideas regarding the objects of the external world are confused, there is a poverty of ideas or an inability to express them in words, yet with all this the patient may have perfect self-possession and a normal regard for himself and his friends. These two association centres are not connected with each other excepting through the someesthetic area. Flechsig, accordingly, seems to assume a more or less significant distinction between the intellectual processes and those of volition. The centres are bilateral and are richly connected by fibres of the corpus callosum, In this they are distinguished from the middle association centre, the island of Reil, which is very sparsely supplied with these commissural fibres. This centre seems to be for the one hemisphere only. It is the association cen- tre more particularly for the cortical elements concerned in the speech function, situated, as it is, in such close proximity to the inferior frontal convolution and to the temporal convolution; it is therefore in connection with the portions of the posterior association centre that are _ connected with the visual and auditory speech functions. ‘These functions are so closely connected with the intel- lectual processes that a few words on the most recent conclusions as to their nature and localization will assist toward a comprehension of the relation of the association centres to the rest of the nervous system. The history of the study of the symptom complex known as aphasia throws an interesting sidelight on the localization of cerebral function. Mention has already been made of the conclusions of Wernicke, Kussmaul, and others. It is quite impossible to enter in this connec- tion into an analysis of this very important chapter of cerebral localization. Collins’ monograph on the “ Gene- sis and Dissolution of the Faculty of Speech” gives a con- cise critical résumé of the various views, and sketches a theory of speech location essentially in harmony with 310 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. that of Déjerine, and, in the opinion of the writer, most satisfactory from all points of view. By the time of Kussmaul the three elements involved in aphasic disturb- ance were well recognized—the motor emissive element, the visual element, and the auditory element. Charcot deserves the credit of emphasizing the fact that so-called motor aphasias are generally kinzesthetic aphasias, de- pending upon the loss of motor images. He believed that there was an articulate speech centre in the inferior frontal convolution, and a graphic kinesthetic centre in the middle frontal convolution. An individual who de- pended in speaking or writing upon kinesthetic images originated in these centres, Charcot called a moteur; one who depended on the visual elements was a visuel; and one who depended on the auditory elements was an auditif. The predisposition to belong to one of these three types might be inherited or might be acquired by education. The centres for the auditory and visual ele- ments lay close together in the neighborhood of the angu- lar gyrus. Charcot taught that these centres must act in harmonious co-operation in order that intellectual ex- pression and conception should be complete. These cen- | Yy Ye = 2 fi ee Wy YY ppg ]/ GY Fic. 902.—The Zone of Language, According to Déjerine. (From Mills.) The zone of language, as indicated by the shaded regions, comprises the portion of the third frontal convolution posterior to the ascending branch of the fissure of Sylvius and the lower extremity of precentral convolution, the upper portions of the first and second temporal convolutions, and the supra- marginal and angular convolutions of the parietal and occipital lobes. tres were, however, independent, and an injury to one might remove certain elements without necessarily inter- fering with the others. This view was a great improvement upon the complex schemes that had been evolved by the Germans, of whom Lichtheim showed that no less than fourteen different areas might be the seat of a lesion producing aphasia. Naming centres, ideational centres, propositionizing cen- tres, and the like were thus cast aside. A tendency tow- ard an extreme of localization for different phases of the faculty of speech was in this way checked. Déjerine made a great step in the direction of still greater simplic- ity. He established the dependence of sensory agraphia upon loss of visual memories in the angular gyrus, which causes alteration of internal language, due to loss of visual images associated with word-blindness. He maintained that writing with the hand was not a specialized func- tion but simply the outward expression through the hand of visual images of various graphic symbols. This view is not accepted by some authorities, notably Mills, Gor- dinier, and Bastian, who still maintain the existence of a graphic centre. It may appear that in certain individual cases the cells in the second frontal convolution may be so trained by education that after adult life is reached the destruction of these cells may cause an inability properly to co-ordinate the muscles of the arm. The graphic-motor centre appears nevertheless to be less stably established as a specifically differentiated portion of the cortex than is the kinesthetic speech centre in the left inferior frontal convolution. Déjerine also contended REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, against the functional independence of the three speech centres, mantaining that the language centre is really a zone constituted of portions of the temporal, parietal, and inferior frontal convolutions of which the three recognized speech centres were focal areas of most intense representa- tion. The extent of this zone of language, which is shown in Fig. 902, is not strictly delimited. Collins says: “It varies in individual cases and at different periods of life in the same individual; namely, it is sub- ject to phylogenetic and to ontogenetic variations as well, the latter depending somewhat upon the speech acquisition of the individual and on the range and num- ber of avenues by which he receives or has schooled him- self to receive information from language.” An injury to any portion of the zone of language will produce disorders of all the elements of speech function. This centre is emissive to the cortex of the Rolandic re- gion, in which there are separate areas for the movements of respiration, vocalization, and lingual and labial action, from which proceed the true motor impulses. The cen- tre in which are stored visual images is situated in the angular gyrus; the auditory centre occupies a position in the posterior part of the first temporal convolution immediately adjacent to the gyrus; the island of Reil may be involved. The speech zone receives and com- bines impulses coming into it from the auditory, visual, and kineesthetic areas. The views of Déjerine are in opposition to the theory of a cortical centre as a restricted area performing a cer- tain specific psychical function and no other. Very simi- lar are the views of Flechsig. The parts of the sensory areas which produce simple sensations have been shown to fade insensibly into the regions which perform func- tions related to more developed perception, and these shade off again into areas of ideation and conception, whose functioning constitutes a summation of impressions from all sense regions. For these areas I believe we may accept Flechsig’s boundaries and name of posterior association centre. Perception, ideation, imagination, memory, thought, reason, etc., are not distinct psychical processes, but all are analyzable psychologically into as- ‘sociations or groups of ideas of more or less remote sen- sory origin. As these mental processes are revealed only through external expression, the cortical areas in which they are represented, of which the angular gyrus is the topographical centre, have a motor side also. In the ‘same manner that the pyramidal tracts from the motor areas act ultimately upon the cells of the lower motor nuclei to induce more complex co-ordinations than are possible when spinal or basal centres act alone, so it is the function of the cells of the association area to act in a more complicated way upon the Rolandic neurones and other projection tracts. A part of this association area, Déjerine’s zone of language, is shown to be connected with the association of those elements which constitute language, a function which has grown in the history of the race to have an amazing significance for man’s in- tellectual life. Consequently I believe we may separate the zone of language (including the posterior third of the inferior frontal convolution, doubtfully the posterior third of the second frontal, the island of Reil perhaps, the angular gyrus, the upper part of the first and per- haps second temporal convolutions) from the rest of the association zone, aS an area representing higher co-ordi- nations peculiarly significant for the processes of thought. We may designate the zone of language as a higher asso- ciation area, or an association area of the second order. This specialized association area has a representation on only one side of the brain, whereas we have reason to be- lieve that both cortical association areas take part in the simpler intellectual processes, although that on the left would appear to be somewhat more important. In spe- cial cases the right zone may perform language func- tions, even in right-handed persons, just as many persons learn to write with the left hand if the right has been in- jured or removed. The prefrontal lobes have been variously designated as “silent” or “functionless” areas, as higher psychical centres, as centres of inhibition, as apperception centres, and as centres of the will and personality. So great is the misunderstanding of the nature of the functions of these lobes, even at the present time, and so often is posi- tive evidence wrongly interpreted and even misquoted, that a somewhat extensive presentation of the facts and conclusions with respect to their functions is demanded. The result of stimulation of these regions is negative, hence they are designated as silent areas. Ferrier, how- ever, reports movements of the head and eyes, and early suggested that these might be movements characteristic of attention, which is the basis of intellection, and that these lobes might therefore be considered areas of higher psychical function. Extirpation of these prefrontal regions in dogs and monkeys by Hitzig, Ferrier, Horsley and Schifer, and Goltz was accompanied by slight, hardly noticeable, mental deterioration. Munk and other ob- servers, on the other hand, deny any loss of attention, perception, thought, or inhibitory power. Many authori- ties report areas for movements of the head and neck and of the trunk, and such centres are now assigned to the roots of the upper frontal convolution. Bianchi (1888-95) contributed the first experimental demonstration conclusively pointing to the psychical functions of the frontal lobes. His experiments were made upon twelve monkeys and six dogs, all of which he subjected to very minute observations both before and after the operation, these observations extending in some cases over a period of years. To determine the bound- aries of the prefrontal zone, Bianchi stimulated electric- ally all of the frontal region and excised all portions from 2 or 3mm. in front of the excitable areas for the arm, face, jaw, and trunk. No special effort was made to pre- serve the olfactory bulb in the monkeys, but it was kept intact in the dogs. The results of electrical excitation agree with the conclusions of other observers. Regions in front of the motor area of head, neck, and eyes were found to be unexcitable with a current of equal strength. Stimulation of the base of the upper frontal convolution produced slight rotation of the head to the opposite side and some lateral displacement of the trunk at the level of the lumbar region. Excitation of the inferior area caused raising of the eyelid together with dilatation of the pupil. The results which Bianchi obtained from unilateral extirpation may be summarized as follows: 1. During the first weeks were noted rotatory move- ments, concavity of the trunk toward the mutilated side, and paresis of the opposite arm (obvious in the more deli- cate movements). These symptoms disappeared at the end of two or three weeks. No oculo-motor disturbances were observed. 2. Tactile sensibility was normal except in one dog (diminished in opposite limb) and one monkey (hypervs- thesia in opposite ear and face). 3. In one monkey there was diminution of hearing on one side. 4. Taste and smell appeared normal. 5. In all cases there were visual disturbances. A piece of sugar was not seen with the right eye until it was nearly in a line with the visual axis. The left eye ap- peared to be normal. 6. There was no perceptible difference in behavior or psychical manifestations of animals mutilated on one side only. They were still susceptible of feelings and capable of new adaptations. When both lobes were removed, there was apt to be a weakness of the left limbs and a tendency to rotate toward the right; but in some cases, after a time, all move- ments were perfectly performed, though in a listless, auto- matic fashion. Sensibility was not necessarily disturbed. There was a decided lack of interest, the habitual state seeming to be one of indifference, and the strongest feel- ings manifested were terror and the desire for food. Affection for the keeper and for the other animals disap- peared. There was a lack of power to make new adapta- tions, to defend themselves, and to resist the influence of sensory stimuli. For example, the monkeys would pick 311 Brain, Brain. up and eat a piece of plaster as readily as a piece of sugar. Even if they spit it out after breaking it up, as sometimes happened, they would return to the fragments and swallow them, apparently unable to resist the re- semblance to sugar. Psychical life seemed to be reduced to the existence of actual sensations; there was no change or resource, and experience profited nothing. Percep- tion seemed to lack some of the factors necessary to the formation of a complete judgment. There were crude sensations, but no co-ordination of simple presentations into representations of higher complexity. Bianchi’s conelusions are as follows: Paralysis of the trunk muscies does not always occur, and it is in any case but temporary. The phenomena observed upon destruc- tion of the frontal lobes cannot be explained by the oc- currence of a temporary trunk-muscle paralysis. Bianchi does not look upon Ferrier’s hypothesis as satisfactory. The facts obtained point to more than a simple defect of attention correlated with paresis of ocular and cervical muscles. Bianchi does not accept the view that the frontal lobes are distinctively inhibitory centres. On the contrary, he justly contends that every part of the nervous system becomes under different circumstances an inhibitory centre. When some particular area of the brain is ex- cited there is an afflux of nervous waves into it, and this weakens the aptitude of other regions to fulfil their func- tions. If busy with a problem one becomes deaf and blind; if auditory or visual centres are strongly excited, the flow of ideas is weakened or arrested. Bianchi’s final conclusion may be stated thus: In the frontal lobes, the incoming and outgoing products of sensory and motor areas are co-ordinated and fused with the emotional states that accompany perception; this area, therefore, determines what has been called the “ psychical tone” of the individual. From the time of Bouillaud many cases have been re- ported of injury to the frontal lobes without sensory or motor symptoms and with no apparent diminution of in- tellectual capacity. In the light of more recent knowl- edge of the effects of lesions in this region of the cerebral hemispheres, it isno doubt correct to infer that these cases were not carefully observed. Forexample, the American Crowbar Case, 1868, in reality a classical instance of con- clusive evidence as to the peculiar functions of the pre- frontal area, is still frequently misquoted and wrongly interpreted in medical literature, despite the critical an- alysis of Ferrier and Mills. The subject of this injury was a young man, twenty-five yearsof age. At the time of his injury, he was engaged in tamping a blasting charge in a rock with a pointed iron bar three feet seven inches in length, one and one-fourth inches in diameter, and weighing thirteen and one-fourth pounds. A pre- mature explosion drove the bar clean through the frontal region of the skull, entering at the left angle of the jaw and passing out ‘near the sagittal suture in the frontal region. The patient recovered and lived for twelve and a half yearsafterward. Froma post-mortem examination of the skull it was clearly seen that the whole lesion was situated anterior to the coronal suture,and hence embraced only the prefrontal region. The following report, by Dr. Harlow, of the patient’s mental condition after re- covery from the injury presents a typical picture of mental decadence: “His contractors, who regarded him as the most effi- cient and capable foreman in their employ previous to his injury, considered the change in his mind so marked that they could not give him his place again. The equilib- rium or balance, so to speak, between his intellectual faculties and animal propensities seems to have been destroyed. He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fel- lows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A 312 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. child in his intellectual capacity and manifestations, he had the animal passions of a strong man. Previous to his injury, though untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart business man, very energetic: and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage.’ ” Corroborative evidence is contained in many subsequent observations. Lepine, in 1877, reported a case of abscess of the right frontal lobe in which the patient “was in a state of hebetude.” Heseemed to comprehend what was said but could scarcely be got to utter a word. Bara- buc, 1876, reported a case of atrophy of the frontal con- volutions in both hemispheres in which muscular power and sensation were unimpaired, but the patient was in a state of complete dementia, marching about restlessly the whole day, picking up what came in his way, mute and quite oblivious of all the wants of nature and requiring to be tended like a child. Davidson, 1876, reported a case of injury to both frontal lobes in which the only symptoms were of a psychical nature. Every action that this pa- tient performed left the impression on the mind of the observer that it was purely automatic or machine-like. Cruveilhier reports a case of complete idiocy from birth until the age of fifteen, with atrophy of two-thirds of the frontal lobe. Ferrier states that the frequent association of idiocy with such defect of the frontal lobes is a gener- ally recognized fact. Williamson, 1896, presented five cases of gross lesions, tumors, and abscesses involving the prefrontal region of one or both hemispheres in which were noticed marked mental symptoms. He gives the following instructive summary of these and forty-five other cases recorded in recent medical literature: A condition of mental decadence; a dull mental state; loss of power of attention; loss of memory ; loss of spontanei- ty ; the patient taking no heed of his surroundings ; sleep- ing during the greater portion of the day, or being semi- comatose. (In two of these it is noted that the patients were in a perplexed mental condition, and constantly appeared to be searching for something.)............+.. 32 Loss of memory; mental failure, but patient cheerful...... 6 Patient suspicious; suffered from delusion, and was oc- Casionally VIOlOME = 21.15) 0jsiexeie:e)e efe's 910-01 le vols vitor tea nee Patient irritable and vViolent.........0ssseccesevees 1 Patient generally asleep; irritable when awake... ou eh Patient ambitious, excitable; memory lost ..............6. 1 Slowness of mental processes; patient simple and childish. 1 nar anxiety ; childishness; hallucinations ; suicidal ten- ONCIES se. Fates civiaic viele ao eine pilsle’elale orate waisig/els eth att aetna It may be considered as having been demonstrated be- yond the possibility of a doubt that injury to one frontal lobe probably, and injury to both lobes certainly, will cause mental deterioration. The amount and character of this deterioration can be ascertained only from a careful detailed examination of the antecedent and subsequent capacities of the individual. In general, the phenomena are slight intellectual degradation, moral and emotional perversion, deficiency of attention, and volitional inef- ficiency. The functions of these lobes seem peculiarly representative of the mental character and general con- duct as these have been developed as the result of a life- time of education and action. These areas may therefore be designated association areas of the third or highest order. They exercise no functions which are not per- formed by the other association areas in less degree of complexity. Wundt calls these areas, centres of apper- ception; an appropriate term if we remember that ap- perception is a synthesis or organized coordination of all the acquired intellectual and other responsive reactions of a brain to the environment of the individual pos- sessing it. As pointed out by Waller, it is thus a “high- level neural synthesis”; similar syntheses of lower level being accomplished by other portions of the cerebral hemisphere. Hughlings Jackson presented a similar view in the suggestion of a hierarchy of neural processes, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, Stripping the individual, who has attained adult life, successively of his prefrontal lobes, the association zone of language, the other association areas, will successively reduce him to a lower grade of human being than he has come to be. The cells of the prefrontal lobes may .be put to different uses in the brains of different persons. Loss of the frontal lobes might leave a Descartes still a fairly satisfactory college professor. The loss of these lobes and of portions of the other association areas might not unfit the college professor to live the normal life of a day laborer whose frontal lobes may be put to a strain to maintain his lower standard of activities. It may be well to summarize the general conclusions of this article and to indicate the point of view from which these conclusions have been examined. It is customary to distinguish between sensory and motor functions of the nervous system, as though certain nerve elements performed the duty of supplying us with sensa- tions, and others contributed an equal service by bring- ing about our movements. Waller has emphasized the objections to this view, maintaining that no centre is exclusively either motor or sensory, but that all centres are both sensory and motor. In this, he correctly inter- prets the facts, which show that brain centres physio- logically perform their functions only when they both receive and emit stimuli. It would clear up many psy- chological notions, that are often confusedly interwoven with reports of the function of various centres, if it were kept constantly in mind that no centre, no neurone, and no nerve is motor, and on the other hand that no centre, no neurone, and no nerve is sensory. All manifestations of life and consciousness are pre- sented in the movements of the organism. These movements are, therefore, the immediate phenomena. A movement, even though it may possibly be restricted to a single muscle, is yet the summation of the con- traction of its individual fibres. The function of any nerve fibre is not to produce a movement, but to stimulate or irritate a muscle fibre to exercise its in- herent function of contracting. Similarly, it is the func- tion of an afferent nerve fibre not to convey a sensory stimulus, but to innervate the neurone or neurones about which its central dendrites terminate. Even the sim- plest reflex action is the result of the co-ordination of at least two nerve elements which are intercalated be- tween the peripheral point of application of a stimulus and the muscle fibres to which the motor neurones run. A single segment of the spinal cord, through the ana- tomical relationship of its neurones, is capable of serving as the reflex centre for complicated co-ordinated move- ments. The explanation as to why certain definite movements are elected to follow in response to a given stimulus is partly anatomical and partly physiological. In the first case, the answer ultimately reverts to biology to explain why neurones should be found so located as to be capable of mediating particular movements in re- sponse to definite stimuli. If we ascribe the cause to the functional habit of the neurones, we again must refer the question to biology to give an explanation of the inheritance of this congenital function, or to tell how neurones acquire during their existence in the organism a particular function or habit. When spinal centres comprise more than one segment, the problem remains the same; more neurones with their axis-cylinder proc- esses have been intercalated, and the response of the peripheral neurones is now conjointly inspired by a larger group of neurones. The movements that result upon stimulation of more extensive centres will be characteris- tically different from those of segmental origination, but . nevertheless these movements will still depend upon the interrelations of the neurons in the centres or upon an acquired or inherited habit. The neurones, which are alone capable of stimulat- ing muscle fibres, are located in the anterior horns of the cord and in the nuclei of the motor cranial nerves. These neurones may therefore be acted upon by peripheral neurones of afferent conduction alone, in which case they will respond with simple movements; or they may be acted upon by other additional central neu- rones. These constitute aggregated masses in the medulla oblongata, the cerebellum, the various basal ganglia, and the cortex of the cerebral hemispheres. As one mass after another is added, the peripheral motor neurones become the recipients of stimuli from larger and larger groups of central neurones, and the co-ordinated movements that follow will represent the combined or co-ordinated influence of their various cell elements. Thus, in the spinal cord, the neurones suflice to bring about simple reflexes; by adding the neurones of the cerebellum, more complex movements of locomotion are produced; add- ing the basal ganglia contributes the anatomical elements that render the reflex mechanism sufficiently complex to bring about the co-ordinated adjustment 01 the various sense organs to stimuli, and also to initiate the instinctive movements of the facial parts and body, which are in- terpreted as expressions of emotion. But these move- ments can all be accomplished without consciousness, and are apparently not acquirable in the lifetime of the individual. They represent instinctive or inherited reactions, simple if relatively few neurones take part in. the co-ordination, complex and often apparently purpos- ive if a greater number of neurones are involved. When to these neurones are added the neurones of the sensory areas of the cortex, of the association area, of the zone of language, and of the prefrontal lobes, the physiologi- cal problem is still merely the question of the anatomical connection of these neurones 7nter se and with the periph- eral neurones. The evidence and the interpretation of what these neurones contribute to the production of com- plex bodily movements involve, however, two factors not necessary of consideration in connection with the functions of centres below the cortex, namely, the rela- tion of consciousness to these processes and the develop- ment of acquired functions or habits. Considered relatively, the functional activities of the cortex are largely the result of an ontogenic education, whereas those of the lower centres are the result of an inheritance of functions acquired in the course of organic evolution. But when anatomical and physio- logical connections have been established in a given adult brain, the physiological problem is then the same as before;—namely, “ What additional complexities of movements are now possible from this additionally com- plex mechanism?” The existence in our minds of cer- tain sensations due to the stimulation of particular areas may assist in establishing the functional relationships of these areas inter se and to lower centres, but the sensa- tions themselves can form no part of a physiological ex- planation of the responsive movements that take place in consequence of such connections. The same principle must apply to the association centres as areas of higher psychical activity. The polite request “Please get off my toe” is as much a motor response of the peripheral neurones as the cry of pain. Experience shows that for the first reaction, certain cells of the cortex must have integral connection with the efferent pathway, which are. not necessary for the much simpler movement. The psychologist cannot distinguish between perceptions and sensations as distinct entities, nor between intellect and imagination as diverse processes, nor does he regard the will as a faculty exclusive of other manifestations and processes of the mind. When it is maintained, therefore, that there are areas of higher level than the cortical sen- sory areas—first, an association area which is the anatom- ical docus for those cells whose functioning is responsible for the phases of consciousness distinguished by the terms knowledge, conception, imagination, thought; a second association area, the zone of language, which is the basis of the function of language as an intellectual and emotional instrument; and still a third region, the prefrontal lobes, which is essential for the preservation of high intellectual and moral character and for volitional effectiveness—it is not meant that these three centres con- tribute each a different mental element to consciousness, nor yet that they are the organs of three diverse mental faculties. The analysis suggests that a human being, 313 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. who may manifest, at different times through speech, conduct, and bodily movement, intellectual capacity and moral character of different grades, must have these three areas intact, if he is to continue to evidence the highest attainment of which he is individually capable. A question, often confusing, is frequently allowed to become involved with this psycho-physiological paral- lelism of increasing intellectual complexity and increas- ing integration of the cells of the central nervous sys- tem. On the one hand, the mere addition of neurones apparently forms a satisfactory explanation of the in- creased complexity of cortical reactions over that of the spinal reflexes. The psychical functions of the brain might therefore represent the result of a mere phylo- genetic increase in nerve tissue, a product of cortical in- tegration. On the other hand, in the human being and higher o- ganisms, it is a common experience to find automatic actions developing from conscious actions, even becoming so set in the nervous system as to appear ineradicable reflexes. Many facts tend to suggest that conscious reaction has always presided over the phylo- genetic development of reflex action; that psychical function thus preceded reflex function, and both helped to determine the course of organic evolution. This view was entertained by Cope, the eminent biologist, and is exploited as a fundamental philosophical hypothesis by Wundt, without doubt the leading psychologist of the day. Many difficulties present themselves to the accept- ance of either theory. It is not necessary for us to take sides on this issue, when considering the localization of psychical function over the cortex of the cerebral con- volutions; but it is desirable to keep this and similar psy- cho-physiological speculations from interfering with an acceptance of reported facts and conclusions. It is not worth while to enter into a consideration of the various theories which have been propounded at dif- ferent times to explain the specific nature of the nerve ex- citation which passes along the nerve fibres of a pathway of conduction. The crudest physical concepts have been called upon to do duty by way of explanation; thus the cell has been likened to a battery and the fibres to con- ducting wires; the nerve stimulus is frequently spoken of as a wave of nervous impulse, similar to but not identical with the electrical wave, propagated at an ap- preciable rate, flowing from nerve fibre to nerve fibre. ‘Theories of electrical tension, of galvanism, of molecular vibrations, and of chemical explosions, are scientific fan- cies rather than hypotheses. When the nervous pathway was shown to be made up of unitary cellular elements, that were contiguous but not continuous, biological theory interpreted the conduction of the nerve stimulus as a series of ameboid movements. It may be said that no hypothesis has yet been formed that offers even the hope of becoming a sufficient explanation. In addition to the original authorities, mentioned in the text, the writer has been much assisted by the critical abstracts of the literature to be found in the publications of Ferrier, Jackson, Macalister, Collins, Gordinier, and Barker, and especially by the “Sketches of the History of Reflex Action,” by Hall and Hodge, in the American Journal of Psychology, from which have been drawn many statements of the established facts of the phenomena of reflex action. Lightner Witmer. BRAIN, GROWTH OF THE.—The following article aims to present a general account of the growth changes which occur in the human brain and cord, between the time of normal birth and the natural end of life, thus in- cluding those found in old age. In dealing, as in this case, with data for the most part very incomplete, the danger of confusion arises from the tendency, on the one hand, to make a general applica- tion of special observations, and, on the other, to inter- pret the absence of positive as equal to the presence of negative evidence. With these words as a preface, how- ever, we may spare ourselves the duty of showing in special instances the limitations of the observations cited. In discussing the changes which occur in the neuraxis 314 (brain and spinal cord = central nervous system), the fol- lowing outline is employed: A. Growth changes in the neuraxis and some of its divisions. B. Growth changes in the neuraxis—considered as the reSultant of changes in the cells which constitute it. 1. Number of neurones. 2. Size of neurones. 3. Changes in the cytoplasm of the cell bodies during growth. C. Growth of the cerebral cortex. A. GROWTH CHANGES IN THE NEURAXIS AND SOME OF Its Divistons.—The human encephalon varies widely in weight at maturity, even when members of the same race and the same social class are alone compared. Dif- ferences in the final weight must be looked upon as re- sulting from differences in the process of growth. The weight of the encephalon at maturity is illustrated by ne Be EAL table based on the observations of Dr. oyd:! TABLE I.—SHOWING IN GRAMS THE WEIGHT OF THE ENCEPHALON AND ITS SUBDIVISIONS IN SANE PERSONS. THE RECORDS BEING ARRANGED ACCORDING TO SEX, AGE, AND STATURE. (From Mar- shall’s tables based on Boyd’s records. ) SANE. MALES. FEMALES. sla Saas d e\/a|é El g|2 sh eh ee ee ; | 2 | SS aee 2 2 D D = = ‘D ‘> 2 ™ L ro) raf fe ra ra =) oD op 5 2 © < 8 sa Be el | ac hs 3 Li hee | Stature 175 cm. and upward. Stature 163 em. and upward. 20-40 | 1409 | 12382 149 | 28 23 134 | 1108 | 1265 | 20-40 41-70 | 1863 | 1192 144 | 27 23 131 | 1055 | 1209 | 41-70 71-90 | 1380 | 1167 137 | 26 24 130 | 1012 | 1166 | 71-90 Stature 172-167 cm. Stature 160-155 em. 20-40 | 1860 | 1188 | 144 | 28 26 137 |°1055 | 1218 | 20-40 41-70 | 138385 | 1164 144 | 27 26 131 | 1055 | 1212 | 41-70 71-90 | 1805 | 1135 142 | 28 24 128 969 | 1121 | 71-90 Stature 164 cm. and under. Stature 152 cm. and under. 20-40 | 1381 | 1168 188 | 25 24 130 | 1045 | 1199 | 20-40 41-70 | 1297 | 1128 1389 | 25 25 129 | 1051 | 1205 | 41-70 71-90 | 1251 | 1095 181 2 25 123 974 | 1122 | 71-90 These records were obtained from 2,086 patients of the Marylebone Workhouse in London, representing, for the most part, the least favored class of persons native to Great Britain. For the purpose of weighing, the en- cephalon was divided into three portions: (1) The cere- brum, including all parts frontal to the midbrain; (2) the cerebellum, severed at the peduncles; and (8) the stem—the midbrain, pons, and bulb taken together. Owing to the fact that these records are based on a workhouse population, it is probable that they represent brains less well grown and earlier subject to senile atrophy than would be the case among the more pros- perous members of the community. The general rela- tions to which we are about to call attention would, however, remain the same. On comparing the sexes Table I. shows that the heavier brains belong to the males; on comparing those of differ- ent stature within each sex, that they belong to the tall individuals; and when those of the same sex and stature are compared, according to age, to those in the prime of life, ¢.e., twenty to forty years of age. Sex and stature, then, are conditions which modify the weight which the brain will attain at maturity, and after the prime of life its weight diminishes. Having indicated the weight at maturity under the conditions of the race and social class here chosen, we have next to determine the weight of the encephalon at birth, and the course of the changes by which it reaches its full size. Vierordt has collected the most complete series of ob- servations for the change in brain weight between birth REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, and twenty-five years of age. The data are taken mainly from German records. They are printed in Table IT. TABLE II.—TO SHCW THE INCREASE IN BRAIN WEIGHT WITH AGE. ENCEPHALON WEIGHED ENTIRE WITH PIA. (Compiled by Vierorat.) MALES. FEMALES. Age. Number Brain. Number Brain of cases. Grams. of cases. Grams 0 months 381 38 384 1 year 945 11 872 2 years 1025 28 961 yee: 1108 23 1040 4 1330 13 1139 5 1263 19 122 6 1359 10 1265 7 1348 8 1296 8 1377 9 1150 o 1425 1 1243 10 1408 4 1284 11 1360 1 1238 12 1416 2 1245 13 1487 3 125 14 1289 5 1345 15 1490 8 1238 16 1435 15 1273 17 1409 18 1237 18 1421 21 1325 19 1397 15 1284 20 1445 33 1228 21 1412 31 1320 22 1348 16 1283 23 13897 26 18 24 1424 33 1249 52/59 1431 33 1224 424 When the data in Table II. are cast in the form of. a curve representing the increase in weight according to age, we obtain the chart given below (Fig. 908). Opec eeeee Oo 6S) 10) 120 14° 16-18 20. 22 Years. wae a COMAPI Se _ ASGRE eee ese Pf Fie. 903.—Curves Showing the Variations in Brain Weight During the First Twenty-Five Years of Life. Based on Table II. In the records of Vierordt it appears that, except at birth and in the fourteenth year, the male has a greater brain weight than the female.* In both sexes the most rapid increase in weight is dur- ing the first year; it continues to be rapid up to the fourth or fifth year, and then becomes slow till the seventh year, when the weight of the brain found in the adult is * During the period of very rapid growth, a slight disparity in the average age of the cases compared easily reverses the weight relations according to sex. This is the probable cause of greater weight in the female at ** birth,” as reported by Vierordt. More careful determina- tions by Mies, 1894, and Pfister,4 1897, show the male brain to be heavier. e nearly attained. From this age on, there is a very slight and very slow growth up tomaturity. At the time when nearly the final brain weight has been attained—namely, the seventh or eighth year—the full difference of 100 grams or more existing between the two sexes is evi- dent. From this, it happens that the rapid growth of the brain has occurred while the body is still very im- mature, since boys of seven years weigh on the average only fifty pounds, and girls but forty- ‘two pounds—this in both sexes being about one-third of the adult body weight; and that the differences characteristic of sex have been established before sexual maturity. The irregular- ities of the curve are to be explained as statistical mainly, and dependent on the comparative smallness of the num- ber of cases available for each year. No significance is to be attached to the dip in the male curve at fourteen years. The very high averages for the males at twelve and fourteen years, and for the females at thirteen years, are to be noted, since they occur in other similar series.® These “premaxima” are most readily explained by as- suming that an overgrowth of the brain during these years of beginning adolescence is one source of constitu- tional weakness, and hence the children dying at this period exhibit heavy brains. There is no reason to sup- pose that within the life cycle of the individual, the brain attains during these years a greater weight than that shown at maturity. From the table of final weights (Table I.) as well as from that just presented on growth, it is plain that the difference in the weight of the encephalon according to sex is one exhibited at birth; that it increases during the growing period, and is maintained throughout life. In the first instance, this difference is most closely asso- ciated with the difference in the total body weight of the two sexes, and is so correlated in the mammalian series. Table I. further shows us that the taller persons have the heavier brains, and this may probably be extended to mean the heavier persons, since when fairly compared, the taller are also probably the heavier. In old age in both sexes, the brain weight diminishes, as the result of shrinkage in the encephalon. There is some reason to think that this involutionary process is delayed in the more favored social classes. It is an important fact that the differences in the weight of the encephalon according to sex, age, and stature are correlated with only very slight variations in the proportional development of the subdivisions of the encephalon as here examined. Table III. shows the percentage value of these subdivisions for different ages at all statures. TABLE IIJ.—SHOWING THE PERCENTAGE OF WEIGHT OF THE SUB- DIVISIONS OF THE ENCEPHALON, THE RECORDS BEING GROUPED ACCORDING TO AGE. BASED ON TABLE I. MALES. FEMALES. a a ad Sei ine se Se cate Be) ge oa fees =| a = D 3) = aq fat 2 a : a 2 Bi . Ape | nef ok todd Na ca Ge < BoleSal owl es BES Pecan < 20-40 100 | 87.52) 10.49} 1.91 “1,96 10.9 | 87.13} 100 | 20-40 41-70 100 | 87.00} 10.6 | 1.94 2.02 | 10.8 | 87.14) 100 | 41-70 71-90 100 | 87.83) 10.6 | 1.98 2.11 | 11.16 | 86.4 100 | 71-90 Here there is a very slight falling off in the propor- tional value of the cerebrum in persons of advanced age. In general the value of the male cerebrum is slightly in excess. In the next table (IV.), where the comparison is made according to stature, there is a regular decrease in the value of the male encephalon with diminishing stature, and at all statures the male cerebrum is slightly in excess of the female. 315 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. TABLE IV.—SHOWING THE PERCENTAGE OF WEIGHT OF THE SUB- DIVISIONS OF THE ENCEPHALON, THE RECORDS BEING GROUPED ACCORDING TO STATURE. BASED ON TABLE I. MALES. FEMALES. @|s|e ales Stature. reall petals eo Are =| 2 | 4 | @| Stature. i Die Os eee tes a Deal res a] o > | 2 BS o o |s8 A} oO iS) n io) o oOo |e 175 cm. and | ay x ye § 163 cm. and “upward. 100 ele an 1.90) |1.91 es 86.93 100 | upward. 172-167 em ....|100/87.2 |10.65}2.08] |2.10)11. 1686.68) 100 160-155 ns 164 em. andl ” 414 a| | low qa § 152 em. ani auiers ¢ |100/87.17/10.6 1.86) |2.09)10.83)87.06)100 heneiandad: In Table VY. it is possible to make the comparison of the proportional development of the several divisions from birth to old age. TABLE V.—SHOWING THE PROPORTIONAL WEIGHT OF THE DIVI- SIONS OF THE ENCEPHALON AT DIFFERENT AGES. (Boyd.) MALES. FEMALES. oe . ool ° g é ° g > =] | bt | 2g =e |G Eo £|es3 = = . va U2 a s Fe 3 Age. 3 3a d 5 g Age. S &a| 42 =) 5 ioe g =] &B 2 2 a o 7a) A es) aR 45 ‘New born.| 92.4 | 5.8 | 1.60 45 |New born.| 92.1] 6.2 | 1.50 22 7-14 87.8 | 10.3 | 1.61 18 7- 87.9 | 10.5 | 1.50 99 30-40 87.3 | 10.6 | 1.98 80 30-40 87.0 | 10.8 | 2.01 95 70-80 87.0 | 10.7 | 2.09 || 128 70-80 86.9 | 10.9 | 2.15 We see here that the cerebellum is the portion least developed at birth, and that between birth and the seventh- year period, the proportions found at maturity are very nearly established. In this table, again, the percentage value of the cerebrum tends to be slightly greater for the male. During the active growing period the reduction in the percentage value of the cerebrum is due, of course, to the more active growth of the cerebellum and stem, while during the involutiopary period—that is, between seventy and eighty years, in this table (V.)—the dimi- nution in value is due to its more rapid shrinkage, as can be seen by examining the absolute weights exhibited in Table I. As regards the subdivisions of the cerebrum, Fran- ceschi® has some observations which are unique. He de- termined the weight of the thalamus and striatum for each half of the cerebrum, in a number of persons and at various ages. During the first five years, the records are too few and indefinite to be valuable. Beginning with twenty-one years, however, he has the following data to present: TABLE VI.—GIVING THE WEIGHT OF THE BASAL GANGLIA IN THE Two SEXES AT DIFFERENT AGES. WEIGHT IN GRAMS. (Franceschi. ) MALES (Basal ganglia). FEMALES (Basal ganglia). Number Number Age. of ob- Mean weight. Age. of ob- Mean weight. servations. servations. Right.| Left. Right.| Left. 21-40 16 41.2 40.8 21-40 20 36.0 36.0 41-71 38 41.6 42.3 41-70 45 37.7 38.0 71-87 22 42.4 42.4 71-87 21 37.7 41.0 This table shows no regular difference between the two halves of the brain. There is, however, a constant difference according to sex, these structures being about ten per cent. heavier in the male; and very curiously, an actual increase in weight in the last age group, when according to the other records the total weight of the 316 cerebrum is /ess than that found during the prime of life. This peculiar relation must be confirmed before it can be regarded as significant. In connection with the determination of the weight of the encephalon as the result of growth there are several problems arising frcm the effect of deformation of the skull during the growing period, and from the possibility of compensatory enlargement of the cranium along one or more axes when its normal growth is hindered. The winding of the child’s head with a compressing bandage, - so as to elongate it in the fronto-occipital axis, has for generations been practised about Toulouse, in France. The study of the brains of aged persons from this local- ity with skulls thus deformed has been made by Ambia- let,? his investigation being the most important study along this line. As might be expected, the effects of this treatment are more pronounced if the deforma- tion has been great than if moderate. Ambialet is able to show, first, that on the average the total weight of the encephalon was diminished, by this treatment, only from two to three per cent; further, that the relations between the cerebrum and the remainder of the encephalon were but slightly modified, the relative value of the cere- brum being reduced a fraction of a per cent., and, finally, that when the cerebrum is divided into lobes, after the method of Broca, the relative weights of these lobes are not significantly different from those found in the normal brain. Since the skulls in question are very evi- dently abnormal in shape, these results indicate that compensatory growth has occurred in the enclosed brain. This result would agree with those recently obtained from the study of crania by Boas,* which he formulates as follows: “Among skulls belonging to the same type, a . breadth above the average is compensated by a height and a length below the average.” This is probably only a special case representing a general tendency toward a final arrangement of cranial diameters which will result in the cranial capacity normal for the individual. The effects of bandaging the skull appear to cause a general nutritive disturbance rather than one limited by the boundaries of the bandage, and the results are not due to direct pressure on the enclosed brain. So far as this aspect of the problem is concerned, we have the beauti- ful researches of von Gudden® on the growth of the skull and brain, which show that while these two struct- ures may to a slight extent mutually adapt themselves to each other, yet the fundamental growth changes in the brain are in a high degree independent of merely me- chanical conditions. In connection with the encephalon, we shall present such data as are available on the human spinal cord. The weight of the cord at different ages can be best shown by a comprehensive tabulation of the results, though these are hardly numerous enough to be used for the formation of a curve (see Table VIL.). It thus appears that the spinal cord increases from an average weight of 3.42 gm. at birth to 27 gm. at matu- rity—an increase of nearly eightfold (7.8),—gaining in weight about twice as much as the encephalon. The encephalon has nearly attained its adult weight at the seventh year, while the cord (see table) at this time has less than two-thirds of its adult weight. So far as this table shows, the cord grows more rapidly than does the brain at every period succeeding birth. The final enlarge- ment of the cord is correlated with the growth of the trunk and limbs that occurs during adolescence—a series of changes by which the cranial cavity is but slightly af- fected. The weight of the cord is therefore closely cor- related with the length of the vertebral column. The proportion of the weight of the spinal cord to the weight of the brain is somewhat greater in men than in women, owing probably to the greater growth of the trunk in the male. ; Since the central nervous system rapidly reaches nearly its full size while the remainder of the body is still quite small, it follows that the proportion of the weight of the entire body represented by it, decreases. To show the relative development of the central ner- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, TABLE VII.—WEIGHT OF THE HUMAN SPINAL CORD AT DIFFERENT AGES. ; Bopy. WEIGHT IN GRAMS. ewe Grams of Observer. Sex and number Age. Tenoth brain for each of cases. Weight “Milli. ‘ Brain. Cord. gram of cord. Grams. | metres. ; Wi ed cand deecannoc 10 males, 116. MAGS yon 5 eisib's.0'0 21 male and fomaleWBIrth to LL dayscsnjseecs os ||reseresssidensarces ; i ‘ ie f : fe ) Range BR weet 11 females, 113. * be 1 iT] BION LOS s nest Ossie aalcie tievslctetsts aie Males ls Danielbekof ...| 200 AVCYADO ACER SO' GAYS coke al'aillllie:s aie cisinre-o1'lts afelslele/sce Females 399.2..| 38 0002 Females 104 WMIGSE sche ts.s +s EPOMBIOA ss sae.03 00 One year six months.......| | 4,856 COBY: Ou wreiviyer stele WM olAecdars obialemter Seres 94 eres +s URIIOM SMa eee ae a: SUX VORIS Seis eisceicre sen emics ail iors cats w cr wtarets 1,060 .. | Re once TB. BBiis ockenasclettes 73 Pele thscsse0.s IfOMBIC Rene regret Ten years nine months.....||.......... 1,330 PASO ean eres Nf ess tcp tara ee OC 69 BaD tere s's.5. 5 cine MMAR aes ead e ale Eighteen years six months..||.......... 1,750 EBAO\ easivnet 27.50 Rieti aroha a ; “ “ Slane Oe NT ee eon 10 males, 51. SECO NOIEG 13 Brctereisty sieeve) NL UULEY Oats raters stcrsisioihiasinic's/arti| leie ee «ca siais' ole sletierniete.e 6 Seite das Range 24-33.3 gm..| 4 females, 49. vous system, as represented by the brain at different ages, the percentages below are given from Vierordt: TABLE VIII.—PERCENTAGE VALUE OF THE BODY WEIGHT AS REPRE- SENTED BY THE ENCEPHALON AT THE AGES NAMED. BRAIN WEIGHT. Age. Male Female RECA MEET ORCaCarcloisafo a's «ie sve s\0 side ove eie-e'ee c'erined 12.29 12.81 NOTIRUEY CHC ema selcieieis aie it's, cc's sn di’via Giese sioe-svsie « 10.50 11.39 PUM NAN VES torsrate leit cise) bles 0:4 ei8'disielereele.vie\s'siviee:s 7.94 7.98 PLM Ie RCM cemeteries a aihicisia'sis ie.sav ole ovis ve.sws eo 5.59 5.56 DME MAREN OREN corel ciecatereie'sa.c)s,scc 4 crereiove e #61. erarvieis 3.62 3.09 PUDUp ATR WOU GUIS Ol atare seo escie,o Cele: axe ieie'ereiolere s eielaeie.e @ 2.43 2.31 PEWOHUYsHVO VORTS: i. scccsccccccccncesceccece 2.16 2.23 This table shows that the proportional value of the central nervous system falls off rapidly during the grow- ing, period and that the proportional value is greater in the female except in the ten, fifteen, and twenty year records. This greater proportional value in the female is the result of the smaller body weight, and the departure from this relation at the periods noted above is a statis- tical deviation, due most probably to the fact that during adolescent growth the increase in body weight occurs earlier in the female than in the male, and hence at these times the table compares the sexes at different phases of their growth. In the growing neuraxis the changes in weight run nearly parallel to the changes in volume, but are a trifle more rapid, owing to the fact that with advancing age the specific gravity of the nerve substance increases and the percentage of water decreases. Although there are numerous observations on the per- centage of water in the human neuraxis at maturity, the changes occurring during growth have not been studied. To supplement this lack, a series of observations (not yet published) made on the white rat by Mr. Polkey and myself will be utilized. From white rats at different ages the brain and spinal cord were removed separately, and the proportion of water in them was determined by drying, at about 97° C. A study of the results shows that at birth the brain contains about 87 per cent. of water and the cord 85 per cent., whereas in old age the brain contains about 78 per cent. and the cord 72 per cent. Thus a differ- ence in the percentage of water exists between the brain and cord at birth, and this difference increases steadily throughout life. In the case of both portions of the neuraxis, the curve representing the diminution in the percentage of water can be divided into three parts. The first part covers the first eight to ten days after birth. During this time the diminution in the percentage of water is slow. The second part comprises the next forty days of life. Dur- ing this period it is very rapid. The third part is from the end of the second period to the termination of life, during which there is a very slow but steady diminution in the percentage of water. The principal change in the central nervous system correlated with the proportional loss of water is the for- mation of medullary substance, and the two processes run very nearly parallel. B. GRowtH CHANGES IN THE NEURAXIS CONSIDERED AS THE RESULTANT OF CHANGES IN THE CELLS WHICH ConstitutTE Ir.—The changes which occur in the cen- tral nervous system as a whole are but the resultant of all the changes taking place in the cells which compose it. An exhaustive list of these components would in- volve the cells forming the blood-vessels and the sever- al sorts of supporting structures—ependyma, neuro- glia, and connective tissue—in addition to the neurones proper. Lack of information concerning changes in the non-nervous structures will, however, preclude more than incidental mention of them, and we can turn our attention to the neurones, not, however, forgetting that the non-nervous structures are much more impor- tant constituents than this treatment of them would in- dicate. 1. Number of the Neurones.—It is first necessary to de- termine when the number of nucleated nerve cells (neu- rones, actual and potential) is fixed. The absence of karyokinetic figures in the human system at the time of birth is presumptive evidence that the number of nerve cells is not increased after that period. Other observa- tions suggest that the production of new nerve cells has been completed in man by the end of the third month of foetal life, and even if the production of new cells has not absolutely ceased at this time, our present evidence indicates that it has become very slow. It may be ob- served in passing, that in the white rat at birth cell di- vision is still very active; but this has little bearing on the condition found in man, because the time of birth in different mammals does not furnish a base line for com- parison, since the maturity of the animal at birth varies enormously with the species, and in this instance the new-born rat is to be compared with the human fetus at least several months before birth. Granted that the number of nucleated nerve cells is formed early, we have next to inquire what happens to them after they have been formed. The studies of His!° and others have shown that the first appearance of these elements is in the form of a neuroblast, which in some cases develops into the complete neurone, while in others it may remain undeveloped for years or even throughout life. When it does undergo development the order of the changes is in general that described by Cajal"! for the cortical neu- rones (the pyramidal cells in the cortex of the rabbit). First, the formation of the axone, then the dendrites, and finally the collaterals; these portions being all well marked before the neurone as a whole has attained its full size. After this, the medullary sheath appears: first on the axone, and later on the collaterals. Never- theless, even in those neuroblasts destined to undergo a complete development these changes do not occur at the same time in all the individuals. The fact that the sum of the nucleated cells which furnish both the permanent neuroblasts (granules of the authors) and the developed neurones is not increased after an early period in the foetal development of man is the first important datum. 317 Brain. Brain, The second fact is that a number of these potential neu- rones begin to develop shortly after their formation, while others delay a longer or shorter time. Thirdly, all statements regarding the number of neurones (nerve cells) in any part of the nervous system are based on the number of fully characterized nerve elements there present, and leave unennmerated the potential nerve cells in the neuroblast stage. Since the well-charac- terized neurones are transformed from the neuroblasts only gradually and in series, it follows that during the earlier phases of growth the nwmber of neurones will increase ; but, as has just been explained, this increase is at the expense of neuroblasts already present in the locality, and does not depend on the formation of new cell elements. From this it follows that in a given part of the nervous system there exists, after cell multiplication has ceased, the paradoxical conditions whereby an increase in the number of nerve cells may occur without any increase in the total number of neuroblasts and nerve cells taken to- gether, since the latter arise by the transformation of the former. In order to follow this increase in the number of neu- rones in the growing animal, it will be advantageous to use the following classification of the cell elements. By this classification, the neurones constituting the nervous system are arranged in three groups. Group I. The afferent neurones: Those furnishing the afferent path- ways and having their cell bodies located in the spinal ganglia or their homologues. In this class the cell body lies outside the neuraxis. Group II. The central neu- rones—constituting the great mass of the central nervous system: All parts of these neurones lie within the wall of the original medullary tube, and all the neurones are concerned with the distribution cf the impulses within these limits. Group III. The efferent neurones—con- cerned in distributing the impulses to the organs of expression. motor element of the ventral horn of the spinal cord, with its cell body within the wall of the medullary tube and its axone passing either to striped muscle tissue or to the peripheral neurones of the sympathetic system. To this last group the neurones of the sympa- thetic system also belong, but in this case both the cell bodies and the axones are found outside of the central system. Since it is the mass of the central neurones which con- stitute the very great proportion of the central nervous system, and since this is the group which undergoes the greatest variation in the mammalian series, it has seemed desirable to separate this group from the other two, and this has been done by means of the foregoing classifica- tion. The studiesof Birge!? on the number of root fibres in frogs of different sizes and of Hardesty '* on the growth of these fibres, show that in the afferent and efferent groups in the frog new axones are continually being formed, and we infer that this new formation fol- lows from the development of neuroblasts which have remained latent for some time. The growth of the frog is so long continued that it is usually said to grow as long as it lives—a statement by no means demonstrated. The conditions are, however, very different from those found in mammals in which the period of growth is much more limited and the size of the body is fixed. In mammals, the available observations are very few. There are no observations on the increase of the neurones in the afferent system of the mammal (Group I.) except the recent study of the dorsal nerve root (fourth coccy geal of the cat) by Dale.'4 Here, the number of medullated fibres was found to be the same at different levels of the root, thus failing to show in the cat the outgrowing fibres revealed by Hardesty in the frog. It appears then that the number of dorsal root fibres in this locality is early fixed in the cat. Passing next to the efferent neurones, the records of Kaiser!® on the “motor cells of the ventral horn” in the region of the human spinal cord, comprised between the fifth cervical and first thoracic segments, inclusive, are as follows: 318 The type of the efferent neurone is the - REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. TABLE [X.—SHOWING THE NUMBER OF DEVELOPED CELLS IN THE VENTRAL HORN IN THE CERVICAL ENLARGEMENT OF MAN AT DIF- FERENT AGES. (Kaiser.) Age. Number of nerve cells. Foetus, sixteen weeks. 50,500 Foetus, thirty-two weeks. 118,330 New-born child. 104,270 Boy, fifteen years. 211,800 Male, adult. 221,200 We assume, of course, in accordance with the explana- tion given above, that the additional neurones are derived from neuroblasts already present. If the numbers here given are interpreted literally, they mean that to the ventral roots of these segments there are added during the periods given the equivalent number of new fibres. Moreover, this addition, according to the table, would go on for a long period, and thus we might expect to find evidence of outgrowing axones in the ventral roots of persons more than fifteen years of age. In the case of the ventral root of the fourth coccy- geal of a cat, Dale was unable to find any evidence of outgrowing fibres; and, furthermore, the studies of Schil- ler!® on the oculo-motor nerves of cats of different ages showed that at eighteen months the number of fibres pres- ent was hardly four per cent. greater than the number found at birth, indicating that here, at ‘least, the number added between birth and maturity was small. TABLE X.—SHOWING THE AVERAGE NUMBER OF FIBRES FOUND IN EACH OF THE OCULO-MOTOR NERVES OF CATS, FROM BIRTH TO: EIGHTEEN MONTHS OF AGE. (Schiller.) Extreme Mean js f Age of specimen. number of | V@viation in. fibro number of fibres. New born, A, B, C (average of three cases) .. 2,942 2,905-2,980 One month, D, E (average of two cases) .... 2,961 2,946-2,976 Four months).Bs;51. son, cbeienicemonmetion tries 3,007 2,995-8,016 Twelve months, G (mother of A, B, F)....... 3,018 3,002-3,019 BighteenmMonths, EH sant ecitecctsteetcrsiciee ee 3,085 3,020-3,050 Using the observations of Schiller to control those of Kaiser, it may be argued that the number of efferent neu- rones in the cat is early completed. Probably the same is true for man; and if it is true for man then the great. increase in the number of cell bodies found by Kaiser in the ventral horns of the spinal cord is due to the develop- ment of central rather than of efferent newrones. Until more evidence on these points is available, how- ever, further discussion would be useless. The total number of neurones found in the brain and cord of man is doubtless variable, but for individuals of the same race the variability is probably not large. This. is concluded from the constancy in the proportional de- velopment of the divisions of the encephalon. The closest determination of the number of neurones in the cerebral cortex of man has been made by Miss Thomp- son,!? who employed as a basis the records of Hammar- berg.'8 According to this computation, there are in the cerebral cortex 9,200,000,000 well-marked nerve cells. Using these results as a foundation, and estimating that. in the remaining gray matter of the neuraxis the cells. have aa average frequency equal to that in the cortex, I have computed that the total number of nerve cells in the entire central nervous system is 11,200,000,000. 2. Size of Neurones.—In this connection it is impor- tant to remember that on passing down the mammalian: series from larger to smaller forms, the nerve-cell bodies. diminish much less rapidly in volume than does the en- tire animal or its central nervous system. From this it: follows necessarily that in the nervous systems of small animals, with their small absolute weight and their com- paratively large cell bodies, the number of the neurones must be far smaller than that found inman. To show the average size of the cell bodies in one locality ina REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. series of mammals, the following table from Kaiser is quoted: TABLE XI.—SHOWING IN A SERIES OF MAMMALS THE MEAN DIAM- ETER OF CELLS FROM THE VENTRAL HORNS OF THE CERVICAL EN- LARGEMENT. THE MEASUREMENTS FOR THE CHROMOPHOBIC AND CHROMOPHILIC CELLS ARE KEPT SEPARATE. (Kaiser.) MEAN DIAMETER OF CELLS IN #. Chromophobe Cells. Chromophile Cells. 1 Plecotus auritus......... 28-53 2 Talpa Europa ......... 36-54 | 1 Talpa Europea......... 17-40 2) Erinaceus Europzus.... 25-45 3 Cercocebus sinicus ...... 33-60 | 3 Cercocebus sinicus....... 238-46 4 Cuniculus domesticus... 41-61 | 4 Cuniculus domesticus... 32-57.5 Be HOMO Ac teus .ceee cee 28-59 1 Bat. 2Mole. 2! Hedgehog. 3Monkey. 4 Rabbit.. 5 Man. With this peculiarity of the cell bodies is to be con- trasted the behavior of the axones. The calibre of the axones is most closely correlated with the volume of the cell bodies, and therefore is not more subject to diminu- tion than the cell bodies themselves; but, on the other hand, the length of the axones necessarily varies with the size of the animal. From this it follows that the total volume of corresponding neurones is always dimin- ished in the smaller animals, and this too despite the fact that the diameters of the cell bodies and the axones may be but little modified. In man a notion of the volume of the average neurone at maturity can be obtained by dividing the volume of the central nervous system, so far as it is composed of neurones, by their estimated number. The volume ob- tained is 90,000 u?.* The neuroblast, according to His,!° has a volume of 700 cubic micra. According to this the average neurone would have increased only about one hundred and twenty-eight times in volume—whereas it can be shown that very © many neurones increase more than a thousandfold. Since a large number of neurones can be shown to in- crease many times more than the average enlargement, it follows that there must bea very large number of neuro- blasts which develop either slightly or not at all. In support of this statement, attention is called to the fact that in the cerebral cortex the smallest neurones have diameters much smaller than that of the original neuro- blasts; while in the cerebellar cortex, the granules with a mean diameter of about 7 « appear still more reduced. There is at present no satisfactory explanation for these cases. The only observations on the changes in the volumes of growing cell bodies in man are those by Kaiser,!> made on the cell bodies of the ventral horns of the cervical en- largement of the spinal cord. TABLE XII.—SHOWING THE VOLUMES OF THE LARGEST CELL BODIES IN THE VENTRAL HORN OF THE CERVICAL CORD OF MAN. (Based on Kaiser’s records of the mean diameters.) Proportional Time volume of A hie Age. the cell bodies, | terval. 1= 700 »3.+ UNOS TIS tae Genee Four weeks........ 1 RMR Saeas anes Twenty weeks ..... Ly SEe ree ties aictes' Twenty-four weeks. Bil 36 weeks. | Fe opera Twenty-eight weeks 67 So CGE Oe Thirty-six weeks... 81 MODE U EYES GI ese a lle die: tne,eirdvenseieise c1ne's 124 overti{ieen years. |i s.css sessed ss 124 ( 15 years. BYLEUIMENELCLULNU cin veysie ood ote staidiets cieieisvercle-tie.cis 48 160 15 years. + The volume 700 «3, in the foetus of four weeks, is taken from His, and the figures represent multiples of that volume. The proportional volumes given in Table XII. show that the rapid enlargement of these cell bodies occurs be- * The estimated number of neurones—excluding the spinal and sym- pathetic ganglia—is 11,200,000,000._ The volume of the central nervous system, composed of neurones = 1,005¢.c. The individual neurone, therefore, has the volume given above. Brain. Brain. fore birth. It gives, however, the same values for the child at birth and the youth at fifteen years, while in the mature man the size is somewhat greater. This is so pe- culiar a result that one is inclined to give greater weight to the statements of Marinesco,!? who finds the cell bodies in question to increase in diameter from their formation up to twenty-five or thirty years, and the giant cells of the cerebral cortex to enlarge for a still longer time. Opposed to Kaiser are also my own observations on the white rat, where the growth of the cell- bodies con- tinues, though at a diminishing rate, up to maturity. It appears from the white rat that the enlargement of the cell bodies is an event that takes place early, in the first half of the period of rapid growth of the neuraxis (first fifty days of life), and that it is mainly accomplished at a time when the axones are still increasing in all dimen- sions, and when medullation is yet very incomplete. The central nervous system in its first embryonic form is amass of neuroblasts; in its completed form it is com- posed mainly of axones and their medullary sheaths. The condition at maturity was brought out by investiga- tions of Miss Thompson,!7 on the proportion of the cere- bral cortex occupied by the bodiesof the neurones. The observations were made on material hardened in alcohol and stained with methylene blue (Hammarberg'*). The cell bodies, under the conditions chosen, represented only 1.57 per cent. of the entire volume of the cortex. If we should increase this to 3 per cent. and include the den- drites with the cell bodies, there would still remain 97 per cent. of the cortex composed of other substances, and in a large measure this 97 per cent. would be repre- sented by medullated axones. All the white substance of the nervous system is, in even a greater measure, composed of the same constituents, so that, taken all to- gether, the medullated axones form the great proportion of the entire system. For this reason at least, this divi- sion of the neurone (the axone) requires special considera- tion. There is in the first place no reason to assume that the relative size of these structures is exactly the same in two brains otherwise comparable. But owing to their great preponderance a slight variation in the size of all the axones and their sheaths might alter very decidedly the gross weight of the encephalon without at the same time necessarily adding to its physiological complexity (Donaldson ®°), It is easy to see that even among the central neurones,—as, for example, the pyramidal cells of the cerebral cortex, the axone of which reaches to the lumbar enlargement of the spinal cord,—the axone with its sheath must be many times the volume of the cell body. The medullated axones of the large pyram- idal cells are of such a diameter that a length of about 0.5 mm. of axone is equal in volume to the cell body. This gives twenty times the volume of the cell body for each centimetre of the medullated axone, and if it ex- tended 40 cm. we should have the cell body with (2040) 800 times its volume as represented by the medullated axone. In the peripheral nervous system the relative mass of the axones is even greater than in the central system. Observations on the white rat show that in the case of the largest neurones belonging to the mid-lumbar spinal ganglia, there is a direct correlation between the increase in volume of the growing ganglion cell body and the area of the cross section of its axone; the ratios of en- largement being similar for both.*? Further, from the time when the medullary sheath is formed on the axones of these cells up to maturity, this sheath exhibits in cross section a simple and constant relation to the enclosed axis—viz., the area of the enclosing medullary ring be- ing very nearly equal to the area of the enclosed axis. This same relation between axis and sheath appears in the peripheral system of man, but the relation existing in the central nervous system has not yet been deter- mined. As to the calibre of the medullated axones in the peripheral system, Westphal *! reports in the periph- eral nerves of man at birth the smallest fibres, including the sheath, 1.2 to 2 ~ in diameter, and the largest 7 to 8 » with an average diameter for all of 3 to 4 4, while 319 Brain, Brain, in the adult the large fibres are from 10 to 15 » in diame- ter. From the third to the sixth week the myelin be- comes more abundant and the fibres double in diameter. In the eighth month there are still some unmedullated portions in the nerves, but these gradually disappear. There is no fixed relation between the volwmes of the cell bodies and the length of the axones which they pro- duce. In the frog Dr. Dunn” has shown that the fibres of greatest diameter in the sciatic nerve pass to innervate the muscles and skin of the thigh, while those going to the parts of the frog’s leg below the thigh have a smaller, average diameter, as well as being individually of less calibre. In this instance, therefore, the fibres of larger calibre tend to run the shorter course. Looking upon the three groups of neurones as elements modified to receive stimulation, and to transmit impulses, it is found that the afferent neurones (Group I.) increase on the receptive side mainly by the expansion of their peripheral axones in the skin and muscles; that the cell body is practically devoid of dendrites receiving but few stimuli, and that their field of influence is determined by the extension of the proximal axone within the central system. The central neurones (Group II.) extend their receptive side by the multiplication of the dendrites, and their discharging side by the extension and ramification of their axones; while the efferent neurones (Group III.) extend their receptive side by the multiplication of their dendrites within the central system, and on their dis- charging side influence a greater or less mass of muscle or of sympathetic neurones according to the ramifications of their axones. From this it will be seen that the complexity of the central nervous system depends first on the ramification of the proximal axones of Group I., second on the rami- fications of ‘both the dendrites and axones of Group IL., and finally on the ramifications of dendrites alone in Group III. It is to this complexity that the growth changes in the neurones ultimately contribute, and there already exist very suggestive observations by Athias?? showing how the growth of the dendrites of the Purkinje cells and of the terminals of the “climbing fibres” are correlated. During growth the cell bodies may also change in shape apparently under mechanical stress. In those parts of the spinal cord like the cervical and tho- racic regions, where the segments of the cord lengthen with the growth of the vertebre, the axes of the mature cell bodies tend to be drawn out parallel to the long axis of the cord; whereas in the lumbar region of the spinal cord, where the segments remain short, the bodies of the efferent neurones are more nearly equiaxial. As the spinal cord increases in weight, the central canal also becomes larger. This involves (in the case of the white rat) a large extension of the wall of the canal, formed by the ependyma cells. Measurement of the ependyma cells shows that the individual elements in- crease but very slightly in their diameters, and hence the great increase in the wall must be due to the inser- tion of new cells. Itseems probable, moreover, that the ependyma lining the other cavities of the neuraxis is ex- tended by a similar process. Neurones tn Old Age.—As a rule the life of the neurone is coterminous with that of the individual. There is, however, evidence that some neurones die before the in- dividual dies, but no evidence shows that new elements take the place of those which thus perish. Old age in man is accompanied by a loss in the gross weight of the encephalon. This has not yet been de- monstrated in animals. In the white rat, however, old age is correlated with the smallest percentage of water found. Systematic studies on the white rat show that in old animals (three or more years) the cell bodies in every division of the neuraxis are shrunken when com- pared with the corresponding elements during the prime of life. Casual observations on man suggest the same changes, though they are well demonstrated only in the spinal cord. Hodge*+ found in a man of ninety-two years a diminished number of Purkinje cells in the cere- 320 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. bellar cortex, and in the spinal ganglia the cell bodies and nuclei were shrunken, the nucleoli absent from all but a few cells, and the cytoplasm was loaded with pig- ment. ‘The coarse changes in old age appear, therefore, in the cell bodies and their parts—while the finer changes will be brought out when the alterations in the cytoplasm with age are described. We should further expect in old age a loss of physiological connections between the separate neurones, but this has not been demonstrated. Changes in the Cytoplasm of the Cell Bodies during Growth.—The studies of Marinesco!® and Biervliet ** show that in the large cell bodies of the efferent group in the ventral horns of the spinal cord the “stainable substance” of Nissl is fully formed at birth—the other portions of the cytoplasm being correspondingly well differentiated. This does not mean that this stain- able substance is formed in all these cells at this time, but only that those neurones which have first devel- oped have already attained this differentiation. The process repeats itself as the neuroblasts, with longer latent periods, gradually enlarge. The neurone in its ‘first embryonic stages stains by the Nissl method so as to reveal a faint blue tint evenly distributed in the cytoplasm. As the element grows, the blue tint be- comes denser at the periphery of the cellbody. Here discrete particles, stained intensely, appear, and these, increasing individually in size, also form a wider band which spreads toward the nucleus. As the features of the mature’ cell become more evident the diffuse blue tint disappears, as though the constituent capa- ble of that reaction had by degrees become concentrated in the masses of stainable substance. This process of the formation of stainable masses is carried farthest in the largest cell bodies—for example, in the large cells of the spinal ganglia; those of the ventral horns of the cord and the large pyramids of the cerebral cortex. The smaller cells of the neuraxis exhibit varying degrees of a less complete formation of the stainable substance, rep- resenting in their final condition phases through which the largest cells have already passed. In old age the neurones undergo involutionary changes one at a time. The masses of stainable substance become disorganized ; the changes progressing from the centre or nucleus toward the periphery. When this occurs, a black or yellow pigment-like substance, often in very fine grains, appears to take the place of the masses destroyed. In the ventral-horn cells true pigment is to be found about the twentieth year, though it comes much earlier in other portions of the neuraxis. With the destruction of the stainable substance, the cell body, as well as the nucleus and its contents, tends to shrink and to stain less strongly. In correlating growth with function, it is often stated that a neurone which is destined to become medullated does not become functional until its medullary sheath has been acquired. The young white rat, in the nervous system of which there is at birth not a medul- lated fibre, is a sufficient contradiction to this dic- tum. It is admitted, nevertheless, that in general the appearance of functional adjustments runs parallel with the medullation of the neurones by which those adjust- ments are mediated; but the two events do not stand in a strict causal relation. The same is true of the stain- able substance of Nissl in the cell body, where the for- mation of well-marked masses is characteristic of full development and full functional power, without being absolutely necessary. By prematurely exposing to light the eyes of young rabbits, the optic nerves of which were unmedullated, Held 2° was able to hasten the forma- tion of the medullary sheath in the stimulated animals. Just how this experiment should be interpreted is not perfectly clear; but if we consider it as due to exercise, then the unmedullated fibres must, in spite of statements to the contrary, have been capable of being exercised even before they acquired their sheaths. Beyond this experiment there are no data on the effect of activity on the growth processes in the central nervous system. In this connection we recall that the encephalon has at- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tained very nearly its full weight at seven years, that is, at a time before any formal school training has begun. If this is granted, then the subsequent functional powers which the child may attain are correlated with a very small addition of substance to the encephalon. This seeming paradox disappears, I think, when the very small volume of the cell bodies in the central system is considered (27.2 gm.), and when it is remembered how avery slight additional weight of material could be so disposed as to add greatly to the physiological complex- ity of the system. Judging by every-day experience, it appears that favorable growth conditions have their effect more in prolonging the growth changes that have once been in- itiated than in hastening prematurely the onset of any given set of changes, and that when growth is hindered, there often appears in the individual a “ prematureness,” which we might call precocity, if it did not tend to be- come permanent in spite of increasing age, and thus in later years show itself in its real form as an arrest of development. C. GROWTH OF THE CEREBRAL CorTEX.—Despite the great interest which attaches to changes in the cerebral cortex, our information is very imperfect. In one local- ity in the white rat, on the lateral aspect of the hemi- sphere at the level of the optic chiasma, the thickness of the cell layer increased as follows between birth and maturity: TABLE XIIJ.—WHITE RAT—THICKNESS OF CELL LAYER OF CORTEX IN MILLIMETRES. Weight of rat in grams. Age. ER BRACE as cio tieicitiwivis aibie;e'e sta. e s SITE Ne sericea 40 MEE er etteteateiciales eras sive craic lsi@is, fe evers Ten days...... 82 me OO SI OCLC BO OAR ESRC OREO Twenty days.. 1.32 Rie Sines oa wetenleeatrals lcs fie we cele ous Pio8,0 Fifty days..... 1.37 dbssdberoeeatsteteieletts siethavcicte ais sieve ere Uo.cle a 07s Maturity ...... 1.49 PAPE RAS eet aivle Dole eis sinis cies 2 ajsisia.a.s'.0, 010 OLAS) ccc 1.36 The data on the change in the thickness of the human cortex are contradictory, some observers claiming that it actually becomes thinner with age. For this reason we omit a discussion of this point and pass to the determina- tion of the increase in the medullated fibres, which all investigators have found. The general course of the development of the fibre systems of the human cerebral cortex is described in the following way by Kaes,*? and we here quote from a sum- mary of his observations given by Miss Thompson. *! _ For the stages earlier than one and one-quarter years, Kaes relies on the observations of Vulpius,?* but the subsequent history is based on his own investigations. The first group of fibres to become medullated are the cortical projection fibres. At birth these appear raying out almost as far as the cortex. At about four months the fibre proprie, the first of the cortical association fibres, become medullated (Fig. 904). At about eight months the first of the intracortical fibres begin to be medullated in those regions which are most advanced. The description of the further development cannot be accurately assigned to definite ages, partly because some regions of the cortex develop so much more rapidly than others, and partly because Kaes examined no brains between the ages of one and one-quarter and eighteen years. A general description of the course of events can, however, be easily derived from a comparison of the different stages of advancement within the same brain. The first cortical fibres which develop shortly after the fibree propriv are a few scattered fibres running parallel to the layer of the fibre propriz on its ectal border. Gradually these latter increase in number, spread for a short distance toward the surface of the cortex and as- sume a stratified appearance. These form the beginning of the “outer association layer” of: Kaes. Before the formation of the outer association layer is completed two other sets of fibres appear; one of these surrounds the Vou. I.—21 Brain, Brain, outer limit of the projection fibres, which by this time have completed their normal growth into the cortex. This is the Baillarger or Gennari layer. It marks the ectal border of the outer association layer, but is com- posed of fibres of larger calibre than the remainder of that layer. The second set of fibres which appears at this period is the zonal layer, at the ectal border of the cortex and immediately beneath the pia. It also is com- posed of fibres of large calibre. The stage of develop- ment just described is characteristic of the advanced portions of the cortex in a child of one and one-quarter years. Its distinctive features are, in brief, a partly formed outer association layer, consisting of some strati- fied fibres lying next the fibree propriz, and the Baillarger layer at its ectal border. At this stage these two por- tions of the outer association layer are separated by a region free from medullated fibres. On its ectal side Zonal layer. Il and Il Meynert layers. pasa a / Stripe of Gennari Ror Baillaréer, \Oufer Associafion Fibrae propriae of Mey nerf 5 Fig. 904.—Semidiagrammatic Representation of the Cortical Fibres in a Section of the Occipital Cortex of a Male Child of One and One- Fourth Years. (From Theodore Kaes, 1894. The designations are the same as those used in Kaes’ papers.) the Baillarger layer is separated from the zonal layer by a second region free from medullated fibres, the region corresponding to the “IT. and III. cell layers” of Meynert. As development continues, the layer formed by the outer association fibres spreads gradually toward the Baillarger layer until it reaches the latter. At the same time the Baillarger and zonal layers grow broader and richer in fibres. The next stage is marked by the ap- pearance of the inner Baillarger layer, and of the first fibres of the II. and III. Meynert layers. The inner Bail- larger layer appears as a narrower line of coarser fibres among the fine fibres of the outer association layer, just ental to the outer Baillarger layer. The fibres in the II. and III. Meynert layers are the finest of the cortex. The first of these to become medul- lated are those lying nearest-the outer Baillarger layer. From the region of its first appearance, this layer (II. and III. Meynert layers) gradually extends ectad, and this process continues until these fibres meet those of the zonal layer. The final stage in the development of the cortex is the addition of a secondary system of coarse fibres to those which have been already described. The fibres of this secondary system are first seen in the outer association layer. Shortly afterward fibres of the same sort are found scattered through the II. and III. Meynert layers. At first these appear singly, but later are organ- ized into a stratum which Kaes identifies with “ Bech- terew’s streak.” Still later, similar fibres appear in the Baillarger layer, and in the most highly developed cortex 321 Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. known they appear as a secondary system of coarse fibres generally distributed through its entire thickness. Very few regions of the cortex reach this highest stage, however, even in the fully grown adult. The period from youth (eighteen years) to maturity is in general characterized by the gradual appearance of the fine fibres in the II. and III. Meynert layers, and the formation of the secondary fibre system of coarse fibres; but in the fully grown cerebrum there are regions which do not reach even the stage at which the fibres of the II. and III. Meynert layers become medullated. The central gyri exhibit the most highly developed fibre systems. The addition of new medullated fibres may continue, according to Kaes, up to the fiftieth year of life, though this limit must certainly be subject to wide individual variations. Flechsig?* has shown that the cortico-petal projection fibres first became medullated in the regions of the cortex, which mediate sensations, and thus by following the proc- ess in these fibres, the sensorimotor areas of the cortex can be mapped out. Their demarcation occurs within the first three months after birth. The intervening por- tions of the cortex form the association centres of Flech- sig and develop later. In the great sensorimotor region about the central fissure Passow*®® has been able to show that the association fibres are at maturity best de- veloped in the more ventral portion which contains the (discharging) pyramidal cells controlling the movements of the lower arm, hand. and face. In the child at one and one-quarter years this layer is equally developed through the length of the gyri, that is, there is no differ- entiation between the cell groups controlling the leg and the proximal portions of the arm and those which con- trol the distal portions of the arm, and from this we infer that the cortical control of the finer muscles and finer movements increases for some time after that for the coarser movements has been completed. Henry Herbert Donaldson. REFERENCES. 1 Boyd: Phil. Trans., 1861. Marshall: Journal of Anatomy and Physiology, 1892. 2 Vierordt: Arch. f. Anat. u. Physiol., 1890. aed Correspondenz-Blatt der Deutsch. Anthropolog. Gesellsch., 894. 4 Pfister: Archiv f. Kinderheilkunde, 1897. 5 Topinard: Eléments d’anthropologie générale, 1885. ® Franceschi: Bull. d. Soc. Med. di Bologna, 1888. 7 Ambialet: La déformation artificielle de la téte dans la région Toulousaine, Toulouse, 1893. 8 Boas: American Anthropologist, July, 1899. ® Von Gudden: Experimental-Untersuchungen tiber das Schaedel- wachsthum, Miinchen, 1874. 10 His: Arch. f. Anat. u. Physiol., 1889. 11 Cajal: Rev. de Ciencias Médicas, Barcelona, 1893. 12 Birge: Arch. f. Anat. u. Physiol., 1882. 13 Hardesty : Journ. Comp. Neurol., 1899 and 1900. 14 Dale: Journ. Physiol., 1900. 15 Kaiser: Die Funktionen der Ganglienzellen des Halsmarkes, Haag, 1891. 16 Schiller: Compt. rend. Acad. d. Sci., Paris, 1889. 17 Thompson : Journ. Comp. Neurol., 1899. 18 Hammarberg: Studien uber Klinik und Pathologie der Idiotie, Upsala, 1895. 19 Marinesco : Revue neurologique, No. 20, 1899. 20 Donaldson: Note on the Significance of the Small Volume of the Nerve-Cell Bodies in the Cerebral Cortex in Man. Journ. Comp. Neurol., vol. ix., 1899. 21 Westphal: Neurologisches Centralblatt, No. 2, 1894. 22 Dunn: Journ. Comp. Neurol., 1900. 23 Athias: Journ. de l’anatomie et de la physiologie, Ann. Xxxiii., No. 4, 1897. 24 Hodge: Journ. Physiol., 1894. 25 Biervliet: Le néuraxe, 1900. 26 Held: Arch. f. Anat. u. Physiol., Anat. Abth., Leipzig, Jahrg. (1896), H. iii. u. iv., S. 222. 27 Kaes: Jahrb. d. Hamburg Staatskrankenanstalten, Bd. iv., 1893- 94, 1896. Since this date Kaes has published several important Hegety 28 Vulpius: Arch. f. Psychiat. u. Nervenkrank., Bd. xxiii., 1892. 29 Flechsig : Gehirn und Seele, Leipzig, 1896. 3@ Passow : Arch. f. Psychiatrie, 1899. 31 Thompson: Journ. Comp. Neurol., vol. x., No. 3, Oct., 1900. 32 Donaldson: Journ. of Nery. and Ment. Dis., Oct., 1900. BRAIN, HISTOLOGY OF.—Mernops.—The nerve tis- sues of the brain may be studied fresh or in frozen sec- tion, by maceration and isolation, or after hardening by various methods. 322 Fresh Tissues.—Nervous tissues from animals can be obtained immediately after death. In human beings a certain number of hours practically always elapse be- fore the material can be removed from the body. Cer- tain post-mortem alterations occur early, particularly in the most labile constituents of the nerve-cell protoplasm. But for ordinary histological purposes tissue obtained from the central or peripheral nervous system within twelve hours after death, provided the body has been kept cool, is sufficiently fresh for minute microscopic examination. For many studies, too, tissue removed as late as twenty-four hours after death, provided the body has been kept cool, is quite satisfactory, though one should be sceptical in such tissue in drawing conclusions from the condition of certain of the microscopic pictures, for example, those of the Nissl bodies, and the so-called fibrillary structures. In examining fresh tissues either teased particles or sections made by the double knife of Valentine may be employed. The teasing method is particularly applica- ble to the study of the peripheral nerves. These may be observed in an indifferent fluid like physiological salt solution. or blood serum, or after the addition of some reagent (acetic acid, osmic acid, caustic potash). Sec- tions of entirely fresh tissue made with the double knife of Valentine are very fragile, besides being extremely difficult to prepare. They may be examined in physio- logical salt solution, care being taken that the cover slip is not pressed upon. Ehrlich’s method of staining fresh masses of tissue will be referred to later. Maceration and Isolation.—F¥or the isolation of histo- logical elements, especially in the central nervous system, the use of some macerating fluid is desirable. A Fasciculus thalamo mammil- ae j laris (Vicg ad’ Azyri). - ENN f-"{Columna fornicis. i we MY ractus opticus. Fic. 966.—Frontal Section through a Normal Human Brain at the Level of the Ansa Lenticu- laris (Anterior to the Nucleus Hypothalamicus). Berlin, Bd. xxvii., 1895, Taf. iii., Fig. 28.) stituent Neurones,”’ New York, 1900.) (After C. von Monakow, Arch. f. Psychiat., (Taken from *‘ The Nervous System and Its Con- 359 Brain, Brain, ess and several basilar dendrites. A single axone de- scends into the white substance. The layer of polymorphous cells contains also a few pyramidal cells, but a large proportion of cells in this layer ¥ Capsulau interna. ~ thalami! See thalami (ant.). Nucleus ies 1 < A \ a Piittamen.” he is Fee ce Aw. iS Globus pallidus, pars“ Nee lateralis, eo Globus pallidus, pars medialis. Commissura anterior cerebri., Fic. 967.—Frontal Section through a Normal Human Brain at Level of Anterior Part of (After C. von Monakow, Arch. /. Psychiat., Berlin, Bd. xxvii., 1895, Taf. (Taken from *‘ The Neryous System and Its Constituent Neurones,’’ New Thalamus. iv., Fig. 33.) York, 1900.) are dendraxones (Golgi cells of type II.), and the so- called Martinotti cells which have ascending axones. The cortex in the region of the sense centres has a peculiar stamp for each particular sense centre. The structure of the occipital cortex near the calcarine fissure may be cited as an example. A section is shown in Fig. 969. The enormous complexity of the various layers is obvious. The cortex varies much in appearance, too, in different animals, as will be seen by comparing a section through the human cortex with one from that of the dog and of / Nucleus lateralis thalami. / Nucleus anterior thalami (a). Capsula ventralis nucl. ant. / Tenia thalami.; art Fasciculus thalamo-mammil- fie laris (Vicq d’ Azyri). ay Stratum griseum centrale. i--k--Pedunculus thalami medialis. &\-" Columna fornicis. v 8 Ansa lenticularis; pars ventralis. the mole (vide supra). A schematic section of the cerebellar cortex is shown in Fig. 970. The structures seen in ordinary hema- toxylin and eosin preparations are illustrated in Fig. 971. hésumé of Conduction Paths in the Brain.—The prin- cipal conduction paths in the brain are made up of several sets of superimposed neurones or neu- rone systems. The conduction paths may be di- vided into the centripetal or sen- sory, the centrif- ugal or motor, and the associa- tive. The centripetal or sensory con- duction paths in- clude those (1) of bodily sensation ; (2) of taste; (8) of smell; (4) of sight; (5) of hear- Sane (eS molec- ular layer. pyramidal layer of small cells. pyramidal layer of large rt cells. layer of poly- morphous ing. ; cells. The centripetal conduction path of bodily sensa- tion carries the impulses concern- ed in touch, tem- perature, pain, muscle sense, and visceral sensa- tions. It consists of a direct con- duction path and Fig. 968.—Golgi Preparation of the Cerebral Cortex. (After Béhm u.-yon Davidoff, ‘*Lehrbuch der Histologie,”’ 8. 282, Fig. 201.) 360 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. several roundabout conduction paths. Just which im- pulses are carried by these various portions of this cen- tripetal conduction path is not known. The most direct conduction path consists in all probability of three sets of superimposed neurones or neurone systems: (1) The peripheral sensory neu- rones (including the ganglion cells, and their prolongations, of the ganglia on the dorsal roots of the spinal nerves, and the ganglia on the sensory cerebral nerves). (2) A set of neurones extending from the nuclei of ter- mination of the peripheral sen- sory nerves to the ventro-later- al region of the thalamus (in- cluding the nu- clei of Goll and Burdach in the medulla and the fibres of the me- dial lemniscus). (5) A set of neurones, the cell bodies of which are situated in the ventro-lateral part of the thalamus and the axones of which reach to the someesthetic area of the cerebral cortex, that is, to the central gyri, the feet of the frontal gyri, and the gyrus fornicatus. The less direct portions of this conduction path concern mainly the portion of the conduction path situated between the per- ipheral sensory neurone systems and the neurone system extend- ing from the diencephalon to the somesthetic area of the cortex. Roundabout routes are made through the cerebellum by way of Gowers’ tract and the direct cerebellar tract to the cerebellum, and by way of the brachium con- junctivum from the cerebellum to the red nucleus. From the red nucleus a neurone system extends higher up, probably to the cortex, possibly indirectly, by way of a new neurone whose cell body is situated in the hy- pothalamus. The conduction path just described is diagram- matically illustrated in Fig. 972. The peripheral sensory neu- rones of the path concerned in bodily sensation have their cell bodies situated in ganglia. These cell bodies give off an axis-cylinder process which bi- furcates T-shaped to form two fibres. One of these fibres runs to the periphery, the other into Fic. 969.—Section through the Cortex of the Gyrus Occipitalis Superior. (After C. Hammarberg, ““Studior ofver Idiotiens the central nervous system. xlinik och Patologi, ete., That going to the periphery is Upsala, 1893, Taf. ii. the stronger, the central fibre Ms-4:) being of smaller calibre. The bundle of medullated central fibres froma given ganglion forms the dorsal root of onespinal nerve. The peripheral fibres are connected in their distal parts frequently with special kinds of terminal sensory apparatus; sometimes they end free in among the cells of the tissues at the per- iphery. The central fibres entering the spinal cord un- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, dergo Y-shaped division with formation of a long ascend- ing limb and a short descending limb. On their way they give off collaterals which run in to end in the gray substance, and the main. fibres themselves ultimately of the sensory neurones of the second order chiefly termi- nate, a new neurone system (sensory neurones of the third order) begins. The perikaryons of this neurone system are situated in the ventro-lateral nuclei of the thalamus. Fic. 970.—Schematic Diagram of the Cerebellar Cortex. Ordinary nuclear staining (the layer of Purkinje cells is omitted); B, section vertical to the surface of a convolution; C, longitudinal section through a convolution. Band OC by the chrome-silver method. 1, Stellate cell; 2, molecular layer; 3, granular layer; 4, medullary layer; 5, axone of a Purkinje cell; 6, moss fibre; 7, cell of granular layer; 8, axone of cell of granular layer; 9, climbing fibre; 10, teloden- drion of collateral of climbing fibre; 11, axone of cell of granular layer; 12, large stellate cell; 13, stellate cell. terminate by running in to end in the gray matter of the central nervous system. The longest fibres from the dorsal roots reach the medulla oblongata and terminate in the nucleus funiculi gracilis of Goll or the nucleus funiculi cuneati of Burdach. The shorter fibres of the dorsal roots end in the gray matter of the central system near the point of entrance. The collaterals and termi- nals of the sensory fibres end in the spinal cord, chiefly about the cell bodies of neurones in the dorsal horns and in the middle zone of the gray matter. The axones of these cells carry impulses farther cerebralward. ‘ Mitral cells Nasal Muc. Memb. Brain, Brain, running through the occipito-thalamic radiation of Gra- tiolet to terminate ultimately in the gray matter of the cortex of the occipital lobe, especially that about the fissura calcarina (Fig. 974). The centripetal conduction path which carries the im- Corpus Soratc’s : Str medull. Fic. 973.—Schematic Representation of Some of the Principal Neurone Systems of the Olfactory Conduction Path. Projected into sagittal plane. Bulb. olf., bulbus olfactorius; Col. forn., columna fornicis; Col. sup., colliculus superior; Comm. ant., commissura anterior cerebri; Corp. mam., corpus mammillare; Corp. pin., corpus pineale; G.0.b., ganglion opticum basale ; Gl. olf., glomeruli olfactorii; Gyr. amb. rhin., gyrus ambiens rhinencephali; Gyr. olf. lat., gyrus olfactorius lateralis; Gyr. 0. m., gyrus olfactorius medialis; Gyr. semiann. rhin., gyrus semilunaris rhinencephali; Gyr. subcall., gyrus subcallosus; Lam. crib., lamina cribrosa ; NV. a. th., nucleus anterior thalami; Nn. olf., nervi olfactorii; Nucl. hab., nucleus habenule ; Ped. cerebri, pedunculus cerebri; Str. long. med., stria longitudinalis medialis; Str. medull., stria medullaris; Tract. olf., tractus olfactorius; Tract. opt., tractus opticus; J, axones of mitral cells going to stria olfactoria lateralis; I’, axoue of mitral cell terminating in gray matter of trigonum olfactorium; JJ, axone of mitral cell terminating in gray matter, whence axone goes to commissura anterior cerebri; II’, axones to anterior commissure; II’’, centrifugal fibre terminating in bulbus olfactorius; JJ, axone of mitral cell terminating in gyrus olfactorius medialis; JV, axones of neurones connecting the olfactory portion of the uncus (gyrus ambiens and gyrus semilunaris) with the hippocampus (cornu ammonis) ; V, axones from hippocampus to fornix; V’, axone to commissura hippocampi; V’’, axones from fornix to septum pellucidum ; vV’’’, axones from fornix to corpus mammillare; V’’’’, axone from fornix to nucleus habenulz by way of the stria medullaris; VJ, fasciculus mammillaris princeps; VJ’, fasciculus thalamo- mammillaris Vieq d’Azyri; VI’’, fasciculus pedunculo-mammillaris, pars tegmentalis (Hauben- biindel of von Gudden); VII, fasciculus pedunculo-mammillaris, pars basilaris (pedunculus corporis mammillaris); VIII, fasciculus retrofiexus Meynerti extending from the nucleus habenulz to the ganglion interpedunculare. (Taken from ‘The Nervous System and Its Constituent Neurones,”’’ p. 779, Fig. 501, New York, D. Appleton & Co., 1900.) visual neurones or optic neurones of the first order are the bipolar cells of the retina. The optic neurones of the second order or central visual neurones include the cell bodies of the ganglion cell layer of the retina and their ax- ones. The axones of these neurones run through the optic nerve to the optic chiasm, where part of them cross over, decussating with similar fibres of the opposite side. In the decussation the fibres from the lateral half of the retina run into the optic tract of the same side, while those from the medial half of each retina cross over to enter the optic tract of the opposite side. The fibres of each optic tract terminate chiefly in the lateral geniculate body, but some of the fibres terminate in the superior colliculus of the corpora quadrigemina and others in the pulvinar of the thalamus. These are the so-called pri- mary optic centres in the brain. Extending from the primary optic centres, especially from the lateral geniculate body to the occipital cortex, is a third group of neurones (optic neurones of the third order), their cell bodies being situated in the primary optic centres and their axones pulses concerned in hearing is a complex path. The periph- eral auditory neurones (audi- tory neurones of the first order) have their cell bodies situated in the spiral ganglion of Corti. Their peripheral processes run out to end free in among the cells of the organ of Corti; their central processes run in through the cochlear nerve to terminate in the pons, chiefly in the nucleus n. coch- lez ventralis and the nucleus n. cochlez dorsalis. In these two nuclei are situated the cell bodies of the majority of the auditory neurones of the second order. The axones from the cell bodies in the ventral coch- lear nucleus go to form the main portion of the corpus trapezoideum, the fibres of the two sides decussating in the middle line. These axones terminate in part in the su- perior olivary complex of the opposite side, but some of them run forward in the lateral lem- niscus of the opposite side. The axones from the dorsal cochlear nucleus run through the striz medullares and plunge down to the region of the superior olivary complex of the opposite side, where some of them terminate, others entering the lateral lemniscus of that side. The lateral lem- niscus receives also axones from cell bodies situated in the superior olivary complex. In the pons, then, the lateral lem- BG badge i on Y.\ Presse C. (/ Nasal portion Temporal portian Fic. 974.—Scheme of Visual Conduction Path. System and Its Constituent Neurones,”’ New York, 1900, p. 833, Fig. 533.) Chiesma opticum 2 niscus represents the main Gea. p, y \ ( oar Y 65) G ° \ = a AS ° - Re < We = * (Taken from *“*The Nervous 363 edie REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain. through the anterior two-thirds of the posterior limb of the internal capsule, through the middle portion of the base of the cerebral peduncle, form the bulk of the longi- tudinal fibres in the basilar part of the pons and the pyr- amids of the medulla. The majority of the fibres un- dergo decussatiou in the medulla and pass down in the lateral funiculus of the opposite side of the cord. Some of the fibres do not decussate but pass down chiefly in the ventral funiculus of the same side of the cord. A few of the uncrossed fibres descend in the lateral funiculus of the same side of the cord. The axones of the pyramidal tract terminate in the gray matter of the pons, medulla, and spinal cord. The impulses running along the upper motor neurones are transferred to the lower motor neu- rones. ‘The lower motor neurones have their cell bodies situated in the so-called motor nuclei of the cerebral nerves and in the ventral horns of the spinal cord. Their axones form the motor roots of the cerebral nerves and the ventral roots of the spinal nerves. They run out to the vari- ous muscles of the head, trunk, and limbs (Fig. 976). The frontal cerebro-cortico-pontal path consists of a set of neurones whose cell bodies are situat- ed chiefly in the feet of the frontal gyri. Their medullated axones descend through the corona radiata and through the anterior limb of the internal capsule to the base of the cerebral pe- duncle occupying its most medial region. These fibres terminate in the pons among the cell bodies of the nuclei pontis. The temporo- and occipito-cerebro-cortico-pon- ® tal path consists of neurones the cell bodies of which are situated in the temporal and occipital lobes of the brain. Their axones descend to Pulvinar of Thalamus esa WU 2 ne i eae FY Nglosso- ry% Fig. 975.—Scheme of Neurones Superimposed to form the Auditory Conduction Path. (Taken from ‘‘ The Nervous System and Its Constituent Neurones,”’ p. 880, Fig. 565, New York, 1900.) ip Knee ad Ankle B£8) sen Mallon end small Toes conducting path for auditory impulses toward Shoulder higher centres. . A large proportion of these fibres terminate in the nucleus colliculi inferioris of the corpora quadrigemina, which therefore repre- sents a very important way-station in the audi- tory conduction path. Some of the fibres of the lateral lemniscus run past the inferior colliculus and terminate first at a higher level. These fibres are joined by the axones of neurones whose cell “%2% bodies are situated in the nucleus colliculi in- ferioris. The conjoint bundle is known as the arm of the inferior colliculus (brachium quad- rigeminum inferius). These fibres terminate chiefly in the corpus geniculatum mediale, though some go by it. In the corpus geniculatum medi- ale are situated the cell bodies of neurones, the axones of which run out through the posterior part of the occipital limb of the internal capsule to terminate in the cortex of the temporal lobe. This auditory centre in the temporal lobe is situ- ated at the junction of the third and fourth fifths of the gyrus temporalis superior and includes the two transverse temporal gyri situated in the fossa Sylvii. The main features of this conduction path are illustrated in Fig. 975. The principal centrifugal conduction paths to be considered are: (1) the general cortico-muscular conduction path; (2) the frontal cerebro-cortico- pontal path, and (38) the temporal cerebro-cortico- pontal path. The cortico-muscular conduction path consists of at least two sets of superimposed neurones. The upper set of motor neurones consists of neu- rones whose cell bodies are situated in the motor region of the cerebral cortex (central gyri and paracentral lobule). They include the large py- ramidal cells of this area. Their medullated ax- ones are those of the so-called pyramidal tract. These axones descend through the corona. radiata, inp? ene? y 2 Fia. 976.—Scheme of Upper and Lower Motor Neurones. (Taken from ‘The Nervous System and Its Constituent Neurones,”’ p. 1037, Fig. 657, arcle New York, 1900.) srseurde ey 364 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain. the base of the cerebral peduncle, where they form the lateral mass of fibres. Passing through the peduncle they terminate in the nuclei pontis. From the nuclei pontis go off axones through the brachium pontis of the cerebellum, there to commu- nicate with cerebellar neu- rone systems which in turn are capable of throwing the lower motor neurones under their influence. A word must be said con- cerning the commissural neu- rones and the associative neu- rones of the telencephalon. Of the commissural neurones the most important are: (1) those whose medullated ax- ones make up the corpus cal- losum,; (2) those whose med- ullated axones constitute the principal part of the anterior cerebral commissure, and (8) those whose medullated ax- ones make up the commissura hippocampi. The medullated axones of the corpus callosum connect the two hemispheres with each other, possibly identi- cal portions of the two hemi- spheres. The anterior com- missure of the brain may be looked upon as a supplement The fasciculus uncinatus extends between the uncus and the basal portions of the frontal lobe. It is probably olfactory in function. The fornix contains the medul- One impor- lated axones of many association neurones. FIG. 977.—Lateral Surface of the Left Cerebral Hemisphere. The edges of the fissura cerebri lateralis (Sylvii) have been pulled apart to show the insular and retroinsuler region. The fasciculus of the corpus callosum. It is generally supposed that this commissure connects the temporal lobes, the basal sur- face of the occipital lobes, and the olfactory bulbs with one another, the corpus cal- losum connecting similar por- tions of the rest of both cere- bral hemispheres. The fibres of the commissura hippo- campi, or so-called “lyre of uncinatus, the fasciculus longitudinalis superior, and the fascicuius occipitalis verticalis are seen in transparency. (After J. Dejerine, ‘Anatomie des centres nerveux,’’ Paris, 1895, p. 757, Fig. 377.) Arc, Fasciculus longitudinalis superior; Fy), M2, gyrus frontalis medius and gyrus frontalis inferior; f,, sulcus frontalis inferior; fo, sulci orbitales; I3 (C), gyrus frontalis inferior pars triangularis ; Fa, gyrus centralis anterior; Fu, fasciculus uncinatus; Ja, Ip, gyri insule; ip, sulcus interparietalis; ma, mp, mf, sulcus circularis Reili; 0), 02, gyri occipitales; oa, sulcus occipitalis anterior of Wernicke; oOF,, of, oF'3, orbital portion of frontal gyri; OpR, operculum, pars frontalis; OpP.2, operculum, pars parietalis; Ov, fasciculus occipitalis verticalis ; P,, lobulus parietalis superior; P»,, lobulus parietalis inferior; Pa, gyrus centralis posterior; Pc, gyrus angularis ; Po, fissura parieto-occipitalis; por, portion of sulcus interparietalis behind the upper part of the gyrus centralis posterior ; pri, sulcus preecentralis ; R, sulcus centralis Rolandi; S (q@), S (v), anterior and vertical ramus, anterior horizontalis, and ramus anterior ascendens of fissura cerebri lateralis Sylvii; 7, gyrus temporalis superior; 7',, gyrus temporalis medius; ¢,, sulcus temporalis superior; t’, t’, vertical rami of the sulcus temporalis superior; ZJ'p, gyri temporales transversi; VS, fossa cerebri lateralis Sylvii. David,” connect the hippo- campus of one side with that of the other. It is prob- ably to be regarded as an olfactory commissural path. The association neurones of the telencephalon connect a portion of one hemisphere with another portion of the same. Some of them have short axones, others have long axones. Those with short axones connect adjacent gyri, those with long axones connect distant gyri, with one another. The association neurones with short axones include the fibre propriz of the cerebral gyri. In the occipital lobe a number of neurone systems with short axones have been worked out. They include the stratum calcarinum, the fasciculus occipitalis verticalis, the fasciculus occip- italis transversus cunei, fasciculus occipitalis transver- sus gyri lingualis, and the stratum proprium. The association neurones which have long axones in- clude the cingulum, the fasciculus longitudinalis superior, the fasciculus uncinatus, the association bundles of the . fornix, and the tapetum. The cingulum is an olfactory tract which extends in a sagittal direction in the white matter of the two main parts of the gyrus fornicatus, namely, the gyrus cinguli and the gyrus hippocampi. The fasciculus longitudinalis superior is a curved bundle extending in a sagittal direction, apparently between the frontal lobe and the occipital lobe (Fig. 977). The fasciculus longitudinalis inferior is usually de- scribed as extending between the lobus occipitalis and the lobustemporalis. The anterior part of the fasciculus, however, is difficult to differentiate, and accordingly its anterior connections are disputed. tant bundle connects the hippocampus with the sub- stantia perforata anterior and is probably olfactory in function. The tapetum is an association bundle connecting the occipital lobe with the frontal lobe (Dejerine). Lewellys F. Barker. REFERENCES, Barker cpa : The Nervous System and Its Constituent Neurones, New ork, Bechterew, W. von: Die Leitungsbahnen im Gehirn und Riickenmark, Leipzig, ii. Aufl., 1899. Bruce, A.: Illustrations of the Nerve Tracts in the Mid- and Hind- brain, ete., Edinburgh and London, 1892. Dejerine, J.: Anatomie des centres nerveux, Paris, 1895. Edinger, L.: Nervése Centralorgane, v. Aufil., Leipzig, 1896. Van Gehuchten, A.: Anatomie du systéme nerveux de l’homme, iii. ed., Louvain, 1900. Golgi, C.: Untersuchungen ueber den feineren Bau des centralen und peripherischen Nervensystems, Jena, Fischer, 1894. von Gudden, B.: Gesammelte und hinterlassene Abhandlungen, Hrsg. von Dr. H. Grashey, Wiesbaden, 1889. von Kolliker, A.: Handbuch der Gewebelehre des Menschen, Bd. i. u. ii., Leipzig, 1896 yon Lenhossék, M.: Der feinere Bau des Nervensystems im Lichte neuester Forschungen, zweite Auflage, Berlin, 1895. von Monakow, C.: Experimentelle u. pathologisch-anatomische Unter- suchungen ueber die Haubenregion, den Sehhiigel und die Regio subthalamica, nebst Beitrage zur Kenntniss frih erworbener Gross- und PS eins ay Arch. f. Psychiat., Berlin, Bd. xxvii., 1895, S. i, 386. Obersteiner, H.: Anleitung beim Studium des Baues der nervésen Cen- tralorgane, iii. Aufl., Leipzig u. Wien, 1896. Ramon y Cajal, S.: Beitrage zum Studium der Medulla oblongata. Deutsch von Bresler, Leipzig, 1896. Sabin, Florence R.: A Model of the Medulla Oblongata, Pons, and Midbrain of a New-Born Babe. Contributions to the Science of Med- icine dedicated by his pupils to William Henry Welch. Baltimore, 1900, pp. 925-1045. 365 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. BRAIN: HYDROCEPHALUS.—See Hydrocephalus. BRAIN, HYPERAMIA OF.—A term used to signify augmentation of the mass of blood in the vascular de- partment of the brain. An equivalent meaning is con- veyed by cerebral congestion. Both terms indicate in the main an extra-physiological accumulation in the cir- culation of the encephalon, and express the same cause united to different symptoms, although congestion seems to apply rather to the sudden or the so-called fluxionary hyperemia resulting from pathological conditions in other parts of the body. Some writers claim that in- crease of arterial blood passing through the encephalon is the only true hyperemia, and that fulness of the brain should more properly be described by “ venous conges- tion,” which is associated with the anzemia consequent upon impaired vaso-motor innervation of the neuras- thenic state. Like that of many questions in medicine, the history of cerebral congestion is old, and so completely chaotic that in recent times the possibility of its occurrence, and consequently its clinical importance, have been doubted. Putting aside its existence as a separate disease, or as a morbid entity having pathognomonic and regular symp- toms, we will assume that the brain, like any other organ, may be the seat not only of anemias but of hyperzemias either circumscribed or generalized. Analogical justifi- cation so obvious as that furnished by experimental in- vestigation on the lower animals, having reference to venous hyperemia, renders the possibility of increased vascularization of the brain admissible. Further evi- dence that the contents of the cranial cavity may vary in quantity is furnished by the intracranial pressure de- tected in infants in whom the fontanels are open, the scalp being raised above the level of the skull, or de- pressed, according as the head is raised or lowered, or when the tension of the fontanel is increased by com- pression of the jugular veins. When a portion of the brain is exposed, after an injury of the skull, it will be observed to enlarge and to-contract in correspondence with the elevation or depression of the head, the presence or absence of sleep and emotional excitement, or with the action of any cause that accelerates the circulation. Any cause that constricts the neck may produce a sen- sation of fulness and pain about the head, with bleeding from the nose; and as a fact of pathological moment that should be emphasized, there may be mentioned the ob- struction to the flow of venous blood resulting from in- sufficient removal of carbon dioxide. In dependent positions of the head, indications of congestion are notice- able in the bloodshot countenance and other evidences of imperfect return of blood. The existence of intra- cranial congestion in such circumstances is further demon- strated by the very red papille and much-congested vessels of the optic nerve. These changes at the fundus of the eye are not found in such gymnasts as trapeze performers and “fly walkers,” because by constant train- ing and habit the animal economy accommodates itself to the abnormal positions. Variability of the cerebral circulation is further shown in the pallor of the fundus of the eye, following the administration of drugs that are known to irritate the vascular nerve centres, as ergo- tin and belladonna. Finally, the existence of cerebral hyperemia is revealed by the necroscopic appearance of the brains of persons or of animals who during life suf- fered from interruption to the perfect return of blood from the head. PaTrHoLoGicaL ANATOMY. —It is quite difficult to recog- nize cerebral hyperszemia on the cadaver, since evident traces are not always left in the brain, and there may be sanguinary ‘stases brought about by gravity and the position of the cadaver which do not exist during life. Venous hyperemia is more easily recognizable after death than the arterial form. In a severe case of hyper- zemia the tissues over the cranium are often found to contain an abnormal quantity of blood; drops of extrava- sated blood from ruptured vessels are seen on the dura after removing the calvarium; the dura, when detached, 366 is of a bluish tint; the sinuses of the dura, the veins emptying into the sinuses, the veins of the pia and the choroid plexuses are distended with blood; and degen- eration of the vessels themselves has been frequently ob- served. The mass of the brain appears larger and swollen, the gyri are flattened, the sulci effaced, and the ventricles may be filled from subarachnoidean effusion; there is a reddening of the whole organ, and the mem- branes are dry and viscous. This reddish or deep-red tint is particularly noticeable in the intense hypersmia of the new-born. The gray substance, increased in consistence, presents a reddish-gray color, and if the hyperzemia has been in- tense, small punctiform hemorrhages are observed. The white substance, also increased in consistence and in den- sity, is of a uniform rose color. On section the brain, without being edematous, shows numerous sanguinary points which are larger than usual, owing to increased size of the capillaries. The meninges are usually filled, and the veins of the cortex are tortuous. If the case has been a chronic one, uniform widening and tortuosity of the vessels are much more pronounced, showing the devel- opment of small aneurismal dilatations, and sequelse con- ditioned by the increased vascularization, such as vascular development of the cellular tissue which enters into inti- mate relations with the glia. The cribriform or sieve- like appearance observed on making a transverse section of the hemispheres is usually regarded as a consequence of long-standing stasis, especially if found in the brains of old people, of chronic drunkards, of opium-eaters, or of maniacs. There are also reasons for believing that cere- bral atrophy may be developed in old people in con- sequence of continuous venous stasis. The pathological changes of arterial hypereemias peculiar to the cranial cavity are rarely observed on the cadaver, as they usu- ally disappear, with its causes, after death. When we take into consideration the imperfect knowledge both of its mechanism and of its anatomical details, and the diffi- culty to establish the relations existing between its numer- ous symptoms and the lesions that determine them, it is not surprising that the existence of cerebral hyperemia is not always easily demonstrable. The condition may sometimes be studied on the large arteries of the pia, but no one has yet distinguished an arterial from a venous hyperemia in the cortical portion of the brain. It is only in such processes as Basedow’s disease that chronic arterial hyperemia is recognized. The difficulty of recognition is increased by the inflammatory changes and simple hyperplasias that are often present, and often overlooked after frequent and long-continued attacks of chronic arterial hyperemia. According to recent researches, when the disorder has run a rapid course pathological changes may be found in the ganglion cells, or in the cortical connective tissue, with nuclear proliferations in the walls of the vessels, and in the fibrillary plexus of the cortical substance. Errotogy.—If there exists a disproportion between the clinical and the post-mortem phenomena of cerebral hyperemia, it must be admitted that the mass of the blood within the skull varies according to certain cir- cumstances, and that the brain, like other organs of the body, is subject both to anemia and to hyperemia; in- deed, it would be surprising if it were not. The question of hyperemia resolves itself into that of a liquid circu- lating in tubes, in which repletion or engorgement can be produced in but two ways, namely, by increase of the inflow, or by diminution of the outflow. Active fluxion- ary hyperzemia may be caused by the augmentation, and passive hyperemia, or that of stasis, by diminution of the sanguinary flow. The force and abundance of the inflow of blood into the vessels of the brain are influenced by the general increase of pressure, and by diminution of local resistance, and it seems as if the greater number of active congestions should be brought under the first category. For a long time the congestive influence of certain exciting drinks, as tea, coffee, and alcohol, has been admitted; and violent muscular exertion, general plethora, cardiac hypertrophy, emphysema of the lungs, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain. Brain, the effects of strong emotion, and the exaggeration of normal functional activity, are believed to take great part in the production of cerebral congestion. But the general increase of blood pressure plays simply a second- ary part in the production of hypersemia, which it can facilitate or augment only when there exist local altera- tions, such as inflammations or vascular lesions. Hyper- trophy of the heart can scarcely be said to cause conges- tion of the brain, except in cases in which the cerebral vessels have become weakened on account of other causes, and the same may be said of other agents that increase the cardiac impulse. Other conditions that tend to produce congestion of the brain, by excess of arterial tension and too consider- able affux of blood, are chronic Bright’s disease, Base- dow’s disease, intermittent fever, extremes of heat and cold, and the tension produced in the vessels of the head and neck when the aorta is constricted or strongly com- pressed by a thoracic or an abdominal tumor. This in- creased arterial tension may also be brought about by the suppression of the normal or pathological secretions, as the menses at the menopause or other period, by the sudden stoppage of hemorrhoidal bleeding when general plethora exists, by the checking of a chronic diarrhea of long standing, or by stopping the hemorrhages in hzema- - tophilia, and it may result from facial erysipelas, or any cerebral or meningeal phlegmasiz, from diverse periph- eral irritations, from extended lesions of the skin pro- duced by burns and eruptive diseases, as variola, scarla- tina, and measles. An important and considerable class of congestions may result from local increase of pressure or collateral fluxions, by means of which the entrance of blood is shut out from the organs. The pathological phenomena sus- ceptible of giving place to collateral fluxions are acute inflammations, thromboses, and embolisms, and the in- farctions resulting therefrom. Interstitial hemorrhage may have the same result; and the energetic local com- pression excited on the skin by the application of thick layers of collodion also produces a considerable local hyperemia. Fluxionary hyperemias from exaggeration of pressure result from general pressure only, not from local, and the greater part of them result from the patho- logical causes above mentioned. Hyperemias of fluxion, by diminution of local resist- ance, may result when atmospheric pressure is dimin- ished or defective, the simplest type of which is furnished by the application of the large exhausting apparatus used to produce cutaneous revulsion. The opposite condition may bring about the hypersemias peculiar to workmen in condensed air (see Caisson Disease). The congestive phenomena brought about by the rapid dis- appearance of a considerable effusion, as ascites, and even by the extirpation of certain tumors, belong to the same category. The condition is also brought about by direct or reflex paralysis of the vaso-motors which influ- ence the dimensions of the vessels in the brain cavity. The innervation of the vascular walls may be directly diminished by any pressure whatever, as that of a tumor, or they may be paralyzed by reflex action in consequence of an irritation of the sensitive nerves of a part, as ob- served in inflammation and in lesions of the nerve cen- tres. Direct paralysis of the muscular walls of vessels may be brought about by variations of temperature. Extreme heat and cold and insolation are capable of pro- ducing intense congestion, and the action of rubefacients is analogous. Direct insolation doubtless acts by raising the temperature of the cranium to such a degree as to cause incipient paralysis of the muscular action of the vessels, and consequent diminution in the tonic force of their walls. The same nervo-vascular phenomena are asserted to be brought about by the action of such sub- stances as opium, alcohol, belladonna, hyoscyamus, hasheesh, stramonium, and amyl nitrite. Fatty or amyloid degeneration of the vascular walls, especially in old people, transforms the vessels into inert and dilat- able tubes, which may favor hypereemias of this order. The presence of entozoa, or of any pre-existing focus of disease in the brain, is also an etiological factor. Finally, all the processes that decrease intracranial pressure favor the creation of cerebral hyperemia. Among them must be reckoned such causes as intense excitement, no matter whether produced by imagination, temperament, or thought. Intellectual work that consists in logical com- binations of ideas seems to be less hurtful in this respect than the more exciting results of a heated imagination, or the depressing effects of sadness, sorrow, and sudden shocks. Passive hyperemia, or the hyperemia of stasis, may re- sult from the active or fluxionary form. It happens that the capillary vessels do not regain their first tonicity after the enormous distention of an active hyperemia, so that the stases become confused with the preceding fluxions. The causes of hyperzmia by stasis are principally those that retard the return of blood from the brain, either by diminution of the local pressure or by increase of the obstacles opposed to the returning circulation. The former exists in the case of alterations of the arterial walls, or when their contractility and elasticity are lost, and in obliteration of the arteries; the second is seen in the hypostases of certain congestions resulting from the long continuance of one position of the body, or in those following certain maladies, and in the compressions ‘of the venous system by tumors or any neoplasm whatever. Venous congestion or hemorrhagic stasis may result from thrombosis, or it may result from congestion of the vena portee, from compression of the jugular, from a stasis in the region of the lesser circulation, from mitral insuffi- ciency, emphysema, and stenosis of the larynx, from all forced expiratory efforts made with closed glottis, and from all processes that invade the abdominal cavity, especially in plethoric individuals. Chronic constipation and flatulence, blowing wind instruments, violent vocal efforts, parturition, epilepsy, hysteria, and chlorosis — these causes are all at fault in producing this variety of hyperemia. Symproms.—Although no one sign of cerebral hyper- zmia is of absolute diagnostic value, yet its existence is often established by the symptoms alone. Fluxionary hyperemia constitutes rather a phenomenon superadded to various morbid states, but in certain cases of mental alienation over-activity of the mind, though always secondary, is very nearly the only pathological manifes- tation. As in anemia, the symptoms met with in exag- gerated distention of the vessels of the brain are those arising from derangements of the sensorium, the organs of special sense, and of the sensitive and motor nerves. The manifestations of cerebral hyperemia are perhaps better known to alienists and neurologists than to other physicians. They are most important as throwing light on the general pathology of insanity, many cases of which, having unknown or undetermined lesions, are doubtless owing to encephalic congestions. Of the cere- bral functions the most strongly affected is the intelli- gence. Delirium is the prominent symptom of cerebral hyperemia. It is generally that of excitement, and in many cases in no way connected with general paralysis there are found to predominate the delusions of grandeur, riches, ambition, and the like, characteristic of conges- tive mania. The superactivity of the cerebral. circula- tion, as well as that of thought and well-being, may be recalled in the rosy excitement produced by wine and good cheer, in the artificial excitement of poetic frenzy, in the beatific visions of psychopathic women, and in re- ligious ecstasy. Insomnia is one of the surest signs of hyperzmia of the brain. In many cases mania and cer- tain hallucinations are connected with a notable hyper- semia of the gray layer. The delirium of febrile conges- tion, which is of a more distressing character, is owing less to quantity than to the quality of the blood, which is warmer, and besides charged with pyrogenic sub- stances, as miasms, pus, and the like. DraGnosts.—General hyperzsthesia most often coin- cides with furious delirium, and headache also exists in a great number of cases. The troubles of the organs of sense are characterized by excitement and irritability. 367 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. It is claimed that paresthesia may be detected with the zesthesiometer. Generally the pupil is contracted. This has been noted in the greater proportion of cases. Paraly- sis of the dilator or irritation of the sphincter is met with. Photophobia, ocular spectra, and ringing in the ears are symptoms peculiar rather to cerebral anzemia or to the venous variety of hyperemia. The ophthalmo- scope teaches but little in regard to cerebral hypereemia. Its use has, however, justified the supposition of a tran- sitory vaso-motor paralysis during frequent and severe attacks of cerebral congestion in a case of hysteria with paralysis and other symptoms. Diplopia and illusive transformations of hearing are often present with the other derangements of the special senses. Recent obser- vations point to the connection between tympanic con- gestion and cerebral hyperemia. Examination of the membrana tympani appears to indicate the state of the cerebral circulation, a fact demonstrated by comparing the state of this membrane before and after the adminis- tration of quinia or amylnitrite. Itis remarked, in con- nection with this circumstance, that evidences of conges- tion are noticed in the vessels over the handle of the malleus, and that the membrana tympani is of a light pinkish color. There is also a rise of temperature in the external auditory canal. Motor disorders are seen in the agitations and strug- gles of the patient. There may be numbness and formi- cation of the extremities, but paralysis does not in any way belong to arterial hyperemia. Convulsions are most common in infants, and belong rather to anzemia or venous stasis than to arterial hypersemia, and they may be confounded with epilepsy. The vomiting sometimes met with belongs also most often to anzemia. The cir- culatory apparatus is more or less disturbed in cases of active congestion. There are palpitation and a sense of oppression; the pulse is full and rapid and the carotids pulsate. This morbid excitability of the heart is particu- larly influenced by emotional disturbance. There is, however, a difference of opinion as to its symptomatic importance. Reflex excitability is preserved. The phenomena of venous or passive congestions are in reality those that commonly relate to aneemia of the brain, and in a given case of anoxyheemia it is difficult to recog- nize whether the condition be owing to want of blood in totality or to venous stasis. In a venous stasis from thrombosis of the sinuses or from embolism the symptoms present are similar to those of congestion, namely, de- rangements of the intelligence, the sensibility, and the mo- tility, and sometimes there is an agitated state of mind, with dilated pupils. Vertigo, photophobia, auditory subjective phenomena, and incoherence of ideas exist, however, to a less degree in this form than in the fluxion- ary, and in the case of delirium it is rather of the mild or demented kind. The symptoms may vary according to age, sex, and other circumstances. Men are more sub- ject than women. The different periods of life known as increase, maturity, and decline are modifying influ- ences, but it does not appear that season exerts any in- fluence. The symptoms may be light or severe, and they may be acute or chronic. In a case of acute jluaionary hyperemia the patient may, after a short premonitory headache and dizziness, fall senseless, with or without convulsive movements. The face is red, the conjunctive are injected, the pupils contracted, the temporals and carotids pulsate vehe- mently, the pulse is hard and strong, the respiration stertorous. There are often convulsive movements and twitchings, especially in children, combined with slight paresis, and the condition often ends in stuporand death. If the case does not terminate fatally, the symptoms de- crease in severity and disappear entirely, or they may pass into the chronic form. The latter is characterized by a sense of fulness and heaviness in the head, by con- tinuous or paroxysmal headache, dizziness, and pulsa- tions of the temporal and carotid arteries. These symp- toms become worse by lowering the head, and by the influence of alcohol, if the hyperemia is still active. The frame of mind is rarely serene, the patient is morose, 368 excitable, and explosive. There is a disinclination to mental labor, with confusion of thought, the ‘combina- tions of which are illogical, morbid, and exaggerated; and symptoms of morbid apprehension, like those com- mon to agoraphobia, are often present. A morbid fear of impotence is a predominant idea in this condition. Other symptoms arrange themselves according to the fundamental conditions that originate the exaggerated distention of the cerebral vessels. The symptoms of passive hyperemia are not entirely identical with the foregoing. There ismore apathy, and the patient is more depressed. It should be taken into account that the poisonous influences of carbon dioxide obtain in this condition: it is the defect of oxygen in the venous blood, and not its quantity, which causes the characteristic phenomena. DraGnosis.—The diagnosis of cerebral hyperemia is often not clear, because of the likeness of the symptoms to those of anemia. The question here concerns the symptoms that have already been mentioned in connec- tion with the excitements of the three great faculties of the nervous system, another enumeration of which would be tedious. In the delirium of anemic origin, as in grave fevers and inanition, the aspect of the patient is quite the opposite of the flushed face, the brilliant eye, and general rugged appearance so often associated with . hyperemic delirium. The essentially transitory char- acter of the excitement met with in these cases, the syn- cope and convulsions, leave no doubt as to the anemic cause of the delirium. Delirium tremens and a certain kind of delirium from lead-poisoning resemble in some points the delirium of cerebral hyperemia, but the dis- crimination is easy when attention is directed to the his- tory of the case and a knowledge of the patient’s habits. Elevation of temperature is of use in distinguishing in- flammatory diseases of the brain from hyperemia. The latter condition is usually apyretic, but at times it is possible to detect an elevation of one or two degrees above the normal by means of the differential calorimeter applied to different regions of the head. Vertigo, epi- lepsy, uremia, embolism, thrombosis, softening, and hemorrhage may be confounded with cerebral hyper- emia; but each of these affections may be distinguished after careful examination into the condition of the urine, heart, lungs, and blood-vessels, and on comparing the symptoms of the afore-mentioned diseases with those of hyperemia. Proenosis.—The prognosis of cerebral hyperzemia de- pends upon the intensity and duration of the symptoms as well as on individual circumstances. Children are more liable to succumb to the intensity of congestion, and in old people cerebral congestion is particularly danger- ous because of the tendency to rupture in the degener- ated vessels. Strong cerebral congestions are as grave as cerebral hemorrhage, and may lead to death. They may also prove the immediate cause of death in such chronic conditions as tumor of the brain and senile degeneration of its vessels. The tendency to such secondary lesions as hemorrhage, softening, cerebritis, and the like is greatly increased by the frequency of the paroxysms. Active cerebral hyperemia, being more amenable to treatment, is consequently more favorable to recovery than is the passive variety. TREATMENT. —The chief therapeutic indication in acute fluxionary hyperemia is to diminish the sanguineous afflux, and this is perhaps best done by judicious inac- tion and careful watching of the symptoms. The condi- tion is not one either of pressure or of cedema, but of an over-active ‘circulation, and the treatment must vary according as the causes are primary or secondary. The nature of the treatment of active congestion from such causes as extremes of temperature, insomnia, or other irritable condition of the brain will, of course, differ from that required by the secondary congestions caused by suppression of the menses, by gout, or by rheumatism. Rest and position are of primary importance ‘during an attack. The head should be elevated and the arms stretched upward. Quiet surroundings, fresh air, and a REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. darkened room are advisable. Local bleeding is recom- mended by most practitioners, but it should be done with a certain amount of discretion and caution. Asa rule it is contraindicated in children and old people, and in hysteric or chlorotic persons. The so-called derivation and revulsion, in which a considerable congestion of the whole or part of the intestinal canal is produced by the administration of 'a drastic purgative, may diminish the afflux of blood to the brain. In fact, main reliance is to be placed upon the derivative effects of croton oil, colo- cynth, and irritating enemata, as of vinegar; the irrita- tion of hot or mustard baths for both the hands and feet; and the production of diuresis. Reflex action is further brought about by the application of a mustard plaster to the epigastrium, and of the actual cautery to the nape of the neck. Cold vigorously applied to the head, in the form of ice, or cold douches upon the head, com- bined with a hot bath, are adjuncts in the treatment too valuable to be overlooked. When there is a heart com- plication it may be met with cardiac medicaments. Among the internal remedies that it is advisable to em- ploy as agents in relieving the cerebral congestion are the bromides, ergot, oxide of zinc, eucalyptus, and hydrobromic acid. When the symptoms of congestion have disappeared, strychnia, phosphorus, and cod-liver oil may be administered with advantage, and at the same time the patient’s nervous system is to be carefully nursed. This is particularly to be enjoined in the case of chronic hyperemia. Complete intellectual rest, fresh air, regular habits, and the disuse of tea, coffee, alcohol, and tobacco should form part of the hygienic treatment. The milk cure and the grape cure may be mentioned as valuable dietetic measures. If the congestion arises from stoppage of a hemorrhoidal flow, leeches may be applied to the anus. Wonderful effects have been thus brought about. Like results have been obtained by applying leeches to the mouth of the uterus in secondary hyper- gemia caused by suppression of the menses. In this con- dition the electric brush applied to the thighs, with douches to the loins and perineum, has been found effica- cious inrestoring the menses. Galvanization of the head and of the sympathetic nerve, having the power to con- tract the cerebral blood-vessels, may often be used with good effect. A systematic course of hydrotherapeutics is often advantageous. In passive hyperemia the causes are to be made the special objects of treatment. Generally, it is a question of restoring vascular tonicity and combating symptoms that in many respects resemble those of cerebral anzemia. Stimulants may be administered in many cases. Satis- factory results have been obtained from ether inhaled in small quantities. The use of cardiac tonics, as digitalis, when the stasis results from some vascular or cardiac lesion, or when there is cirrhosis of the kidney, is a ques- tion that still admits of a satisfactory solution. Irving C. Rosse. BRAIN: LESIONS OF THE CORPORA QUADRI- GEMINA.—In discussing the lesions of the corpora quadrigemina in man our material is scanty, and it is often impossible to distinguish between the results due to injury of one portion of the brain and those due to the destruction or irritation of neighboring parts. The corpora quadrigemina of mammals correspond in structure to the optic lobes of frogs, birds, and fishes. Little is known about purely destructive lesions of the corpora quadrigemina inman. Experiments on animals would lead us to suppose that destruction of the whole corpora quadrigemina would result in complete blind- ness, and unilateral lesion in hemianopsia. In man, how- ever, this does not always occur. In a case related by Eisenlohr, a revolver bullet entering through the forehead passed directly into the right corpus quadrigeminum and there remained. The power of sight was only par- tially lessened at first—R. $9, L. 28; later, R. 29, L. 29, (Monakow). Monakow concludes that the destruction of a whole anterior corpus quadrigeminum in man causes only moderate affection of sight and leaves the color Vou. IT.—24 Brain, Brain, sense intact. Local lesions of the corpora quadrigemina may cause dilatation of the pupils in one or both eyes and the pupillary reaction to light and accommodation may be much impaired. As the process advances toward the base, disturbances of the ocular muscles become prominent. Total ophthalmoplegia is rare, but there is paresis of the various muscles, not homologous, incom- plete, and developing unvenly. The posterior corpora quadrigemina have nothing to do with sight; after iso- lated lesion of them no effect on vision is observed. Paralysis of the fourth nerve (unilateral or bilateral) and disturbances of chewing have been found in such cases. Lesions of the corpora quadrigemina also produce both ataxia of movement and cerebellar ataxia. Tremor re- sembling that of paralysis agitans and sometimes choroid movements either of the opposite extremities or bilateral may exist. An important symptom in cases of lesion of the pos- terior corpora quadrigemina is a dimunition of hearing in the opposite ear. In cases of tumor or foreign growth in the corpora quadrigemina or their neighborhood the adjacent regions are liable to be affected and symptoms strictly referable to the disturbance of these regions are apt to occur. These symptoms, as well as the general, that is non- localizing, symptoms of cerebral tumor cannot be dis- cussed here, but must be considered as of much impor- tance in forming the diagnosis. Welliam N. Bullard. BIBLIOGRAPHY. Bastian: Lancet, July 25th, 1874. Bernhardt: Beitrage zur Symptome u. Diagnostik der Hirngesch- wiiste, Berlin, 1881. Ferrier: The Functions of the Brain, London, 1876. Ferrier: Glioma of the Right Optic Thalamus and the Corpora Quad- rigemina. Brain, 1882, v., p. 123. Nothnagel: Topische Diagnostik der Gehirnkrankheiten, Berlin, 1879. Putzel: In Supplement to Ziemssen’s Cyclopzedia, New York, 1881. Ross: Diseases of the Nervous System, New York, 1883. von ate uf _m Nothnagel’s Specielle Pathologie u. Therapie, vol. ix; baeL, ie BRAIN: LESIONS OF THE CORPORA STRIATA.— By corpora striata is designated the lateral portion of the collection of gray matter called basal ganglia; these are further subdivided into two parts, the nucleus caudatus and nucleus lenticularis. These parts of the brain are rarely if ever the seat of independent states of disease. The lesions found in this region of the brain are almost exclusively vascular or tumors. The symptomatology of disease of the corpora striata is very obscure, and reports of pathological without dis- tinct clinical findings are often met with. The main symptoms to be expected from lesions in this neighborhood will be dependent upon implication of the adjacent capsular structures. As symptoms pointing with some probability to involvement of the corpora striata, these motorial irritation phenomena are cited: choreatic and athetotic twitchings and spasms or con- vulsive laughter or crying. Joseph Fraenkel. BRAIN: MALFORMATIONS. See Teratology. BRAIN: METHODS OF REMOVING, PRESERVING, DISSECTING, AND DRAWING.—S 1. This article has no ‘direct reference to microscopical or pathological require- ments, which are provided for elsewhere in this work and in special papers.* Neither is it designed for neurologi- cal specialists, or for those who may have the benefit of their counsel, or access to large libraries; but physicians and students at a distance from medical centres, who de- sire to attain a real and personal acquaintance with the gross anatomy of the human brain as an aid to the com- prehension of its minute structure, its functions, diseases, and mental relations, may profit from an account of the methods found useful in a laboratory where many stu- dents have prepared for a medical course. * For example, that of Donaldson, 1894; see the Bibliography at the close of this article. 369 Brain, Brain, § 2. Need of More Attention to the Subject.—In the large city schools considerable time is now devoted to the anat- omy and physiology of the nervous system, and instruc- tion is given especially in histological methods; but even there the gross anatomy is not always adequately worked out by the student himself upon good material, and it is to be feared that in some institutions the conditions de- scribed seventeen years ago (W., 1884, a) may still pre- vail. 3 & 3. Inasmuch as he is permitted to clean scrupulously the abdominal muscles before examining the vastly more important viscera, the average.first-year student is at least consistent in deferring the removal of the organ of the mind until he has carefully dissected the muscle that wrinkles the forehead. With saw and chisel he lacerates the brain, tears it in the effort to save entire the sacred skull-cap; injures it yet more in the process of extrac- tion,* and places it upon a hard, flat surface, where its own weight completes the rupture of delicate connections and hopelessly distorts its shape. Here he leaves it (having to clean some bones), perhaps for a day or two, probably drying, and either freezing or decomposing ac- cording to the temperature. He then transfers it to a basin or pail, covers it with strong alcohol, notes with satisfaction that the surface hardens rapidly, feels sure of finding out all about the brain, and sees himself a fu- ture neurological expert, perhaps even an asylum super- intendent. In due time, armed with his “Gray” and a big knife, he succeeds in identifying the cerebellum, the chiasma, and the pons. Upon the cerebrum he recog- nizes the Sylvian fissure, but is doubtful about the cen- tral; moreover, the effort to detach the dried-on pia cre- ates so many undescribed depressions and _fissural confiluences that he imagines, d da Benedikt, that it be- longed to some hardened criminal. Lifting the occipital lobes, his fingers readily enter cavities which must be the “descending horns of the lateral ventricles,” a trium- phant refutation of the opinion of certain “theoretical ” anatomists that there is no such thing as a “ great trans- verse fissure” till artificially produced. He then slices the brain secundum professoris artem, and is so pleased at demonstrating the “centrum ovale majus” that he is not seriously disturbed at the presence of an unexpected rent in the callosum and an irregular orifice at either side. Continuing his operations, he finds the interior of the brain a mass of amorphous pulp; suspects that the names in the books have much the same significance as those of the heavenly constellations; modestly admits that he may not be sufficiently advanced to comprehend the brain, and resolves that, when this branch is undertaken again, his armamentarium shall consist not of a scalpel but a spoon. § 4. The more important of the macroscopical methods of studying the brain, pursued in the Neurologic Labora- tory of Cornell University, are summarized in §§ 7-82. From the nature of the case a strictly logical sequence is impracticable; certain of them are subsequently described in detail.+ § 5. Acknowledgments.—Did space permit, I would gladly specify the sources of such of these methods as are not original, and the points in which efficient aid has been rendered by my students, past and present, in either carrying out my own ideas or in improving upon them; the following deserve particular mention: P. A. Fish, 8. H. Gage, F. L. Kilborne, B. F. Kingsbury. W. C. Krauss, B. L. Oviatt, M. J. Roberts, M. G. Schlapp, Theobald Smith, H. E. Summers, B. B. Stroud, and F. L. Washburn. *The article ‘‘ Anatomy ’’ in the last edition of the Encyclopedia Britannica G., 876) seems to acquiesce in the present state of things as beyond remedy: ‘‘In taking the brain out of the cranial cavity this commissure [the medicommissure] is usually more or less torn through, and the cavity [diacele] is consequently enlarged.” + That these methods are fairly successful may be concluded from the facility with which those who practise them receive the more advanced or specialized instruction imparted at the great medical schools, and from the nature of the preparations in the museum. Yet there is hardly one of these methods that is not susceptible of change for the better ; indeed, the constant effort to improve them has been a serious hindrance to the completion of this article. 370 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. § 6. Order of Treatment.—Introduction and Acknowl- edgments, §§ 1-6. Summary of Principal Methods, §§ 7-52. Preliminary Work upon Certain Animal Brains, $$ 53-59. Removal of the Adult Human Brain, §§ 60-71. Removing the Brains of Infants and Fetuses, $$ 72-80. Preservative Liquids, §§ 81-90. Injection into the Cavities and Arteries, §$ 91-115. Dry Preparations, §§ 116-119. - Injection Mixtures, §§ 120-121. Economics of Alcohol, §§ 122-127. Storage and Transportation of Brains, §§ 128-181. Dissection, $$ 182-136. Instruments and Apparatus, §§ 137-144. Labelling and Recording, §§ 145-151. Methods of Representation, §§ 152-171. Bibliography. § 7. Before dealing with the human brain, the various processes of removal, preservation, and dissection are practised upon the more accessible brains of the sheep (pp. 158, 178, 208, 209, 872, 374, 382) and the domestic cat (pp. 149 and 151): “ Fiat experimentum in corpore vii.” § 8. Fetal and infant brains are utilized not only for what is learned from them as such (pp. 1386 and 185-189), but also as preliminary to dealing with the adult organ when, as is sometimes the case, the latter is less readily procured and removed. § 9. Although, in most cases, the ultimate object of neurologic study is the comprehension of the structure and functions of the human brain, yet it is held to be de- sirable that students should understand the general pat- tern of the organ and recognize both the conformity of the human thereto and the degree of its departure there- from; for this purpose are studied the brains of certain lower vertebrates, especially the green turtle (Chelone mydas (p. 148) and the sheep (pp. 209 and 374).* § 10. Although the pattern of the cerebral fissures of man and the other primates differs widely and perhaps irreconcilably from that of the other mammals (p. 198, § 303), yet the methods of fissural study apply equally to all, and the comparative simplicity of the fissures in dogs and especially cats renders them convenient subjects upon which to commence a difficult branch of neurology (pp. 187-206).+ § 11. Still other animal brains may be found useful in the illustration of special points (e.g., pp. 140, 148, 150, 170, 204, and 207); but I strongly deprecate the extent to which merely curious or startling facts of compara- tive anatomy are sometimes introduced into medical pub- lications. § 12. Before the detailed study of the contours of the masses there is gained a general idea of the cavities, their connections and their circumscription. § 18. Skulls—which may be purchased or easily pre- pared under nearly all circumstances—are less esteemed — than brains; the “kernel” is more highly valued than the “shell.” § 14. The infant cranium is divided with scissors and nippers (Fig. 986), or softened by ten per cent. nitric acid so as to be cut with the knife. § 15. The common method of dislodging the adult cal- va (calvaria or skull-cap), after the circular cut with the saw, by “inserting a strong hook and giving a quick jerk,” is held to be artistically brutal and anatomically futile; a second, sagittal, section is made, a little way from the meson (middle line) and the calva removed in two pieces; § 60, Z. § 16. Excepting for special reasons the dura is retained * Were opossums as common as cats in most civilized lands the less preponderance of the cerebrum and cerebellum over other parts would warrant the general study of their brains. +I desire to reiterate here the conviction expressed on several pre- vious occasions as to the inutility of the brains of ordinary monkeys for the elucidation of human fissural problems; indeed, our present comprehension and nomenclature of cerebral elevations and depres- sions would be far better than they are had neither Gratiolet nor any other anatomist ever examined a monkey brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES until the calva is removed, and it is sometimes extracted with the brain. § 17. The fresh brain is removed over brine (saturated and filtered), supported in it during the operation, and kept in it until its final disposition is made. § 18. A fresh brain in the dura is lifted by the latter and supported in liquid by attaching cords to the dural edges, the other ends of the cords being carried over the rim of the pail or other vessel and wound about hooks, or otherwise attached. § 19. A fresh brain deprived of its dura, if it is to be either studied from any aspect or injected into the arte- ries or the cavities, is supported and steadied in a pail of brine by passing under it a towel or broad strip of cloth, the ends of which are secured to the pail by hooks, tacks, or otherwise; the brain may thus be kept at any height in the brine, and rotated without touching it. § 20. The fresh brain is never allowed to bear its own weight or to rest upon a flat surface, but is supported in the calva or in a bowl of appropriate shape, or in a liquid of equal specific gravity, or on a bed of ordinary cotton.* § 21. The use to be made of a brain is, if possible, de- termined upon in advance. If only part is to be em- ployed for a specific purpose, the rest is cut away and preservative effort concentrated upon the selected por- tion. § 22. When the brain is to be preserved entire, espe- cially for the elucidation of membranous attachments and the circumscription of the cavities, alcohol (or other active preservative liquid) is injected into the arteries by continuous pressure, and thus carried directly to the tis- sues; §§ 99 and 114. § 23. When a separated head is obtained the brain is sometimes hardened in place by the continuous injection of alcohol (§ 99); it shrinks somewhat, but retains its natural proportions. Such a head, medisected with a sharp saw, is instructive in many respects (Fig. 670, p. 141). Sometimes sections are made in other directions, or the calva removed as with the fresh brain (§ 60). § 24. For macroscopic purposes freezing is avoided, as tending to leave the mass friable. § 25. If a specimen is to be used especially for the elu- cidation or demonstration of the contours and circum- scription of the cavities and the lines of attachment of membranes and plexuses, strong alcohol, or an alcoholic solution of zinc chloride, is injected into the cavities and the arteries. § 26. If certain portions of the cavities are in question, free access of the preservative is gained by widely open- ing some other region, as, ¢.g., by cutting off a frontal, temporal, or occipital lobe. § 27. Unless there are special reasons to the contrary, brains are transected in the narrow region of the mesen- cephal (gemina or optic lobes) (Figs. 689 and 756); the cerebral and cerebellar portions are then removed sepa- rately with greater ease and less risk of laceration(§ 60, J). Each of these regions is medisected, if desired, more ac- curately than the entire brain can be, whether before or after hardening, and the two divisions of either half are subsequently apposed for study, or even attached for ex- hibition. § 28. When the mesencephalic region itself is to be preserved intact, by lifting the occipital lobes a little more the transection is made through the diencephal (thalami) (Fig. 707). § 29. For the study of fissures and gyres, the cerebrum (with the thalami) is commonly medisected (§ 61), and each half hardened by placing it on its mesal surface in the preservative. *So general has become the use of absorbent cotton that one does not always realize that its very excellence for certain purposes renders it less appropriate for others; when wet it packs very closely, where- ra in any liquid, the ordinary cheap cotton retains its elasticity much onger. +The city neurologist has perhaps only to decide that a brain is needed: but others, like the writer, may find it advantageous to keep in a portfolio slip memoranda of what he wishes to do with fresh brains, or heads, adult or young, as the case may be; when the op- portunity occurs he has only to decide among several things that might be done, and little time is lost. Brain, Brain, § 80. So far as possible, incisions of the brain are made in liquid or while the scalpel is irrigated; with hardened brains alcohol is used; with fresh a salt solution. § 31. Specimens which have become dry and distorted are immersed for a day in weak spirit (twenty-two per cent.), and then replaced in the strong alcohol. § 382. When part of a thin brain preparation (¢.g., a hy- drocephalous cerebrum like that shown in Fig. 715) has dried, it is restored by placing on the spot a bit of absor- bent cotton wet in water. § 33. To remove a delicate specimen from a vial, the vial is immersed in a dish of alcohol and the specimen floated out; to replace it, if the alcohol is clear, the vial is immersed and the specimen floated in; if turbid, the specimen may be transferred upon a bit of paper, a watch glass, spoon, or wpon—znot between—the points of the fine, curved forceps (Fig. 985). § 34. Friable specimens are infiltrated with paraffin; see the paper by W. C. Krauss (Buffalo Medical and Sur- gical Journal, November, 1888) and publications there referred to. § 35. Defibrillation—the tearing of brain substance in the direction of the least resistance so as to make “ cleav- age preparations ”—is not regarded as affording conclu- sive evidence of tract arrangement; but it is practised in illustration of facts determined by more exact methods, microscopical, pathological, and experimental. § 36. For the decided maintenance or increase of the color differentiation of the two kinds of nervous tissue, alba and cinerea (p. 139, Fig. 66), specimens are im- mersed in, or injected with (or both), a solution of potas- sium dichromate (§ 85); or Miiller’s liquid (§ 86). § 87. When the color and microscopic structure are subordinate to purely morphologic considerations a choice is made between four compound liquids devised by past or present assistants in the laboratory, the zinc-glycerin (§ 88) or the zinc-formalin (§ 89) of Fish, the saline-alco- hol ($ 90) or the simplified saline-alcohol (§ 90) of Stroud. § 88. Dry (mummified) preparations are made accord- ing to the improved method (turpentine and castor.oil) of P. A. Fish (§ 117). § 39. When the larger vessels are to be studied, Gage’s modification of Pansch’s starch mixture is em- ployed (§ 120); if the ultimate vascular supply is in ques- tion, a fine gelatin mass is used (§ 121). § 40. When practicable the leptomeninges (pia and arachnoid) are removed as soon as they loosen from the surface, which is commonly within two days after im- mersion; but this is not essential, for they may be re- moved at any subsequent period, with merely somewhat more care against breaking or wounding the hardened brain. § 41. Alcoholic brains are examined before fresh ones. § 42. The size and form of the cavities are maintained and the preservation of their immediate parietes is in- sured by injecting alcohol into them; Fig. 731. § 48. The forms of cavities are ascertained by making solid casts; Fig. 718. § 44. Encephalic fragments, and poorly preserved or distorted specimens serve for preliminary dissections, so that the perfect material may be more completely uti- lized. § 45. Before attempting to comprehend large sections, involving perhaps several parts but distantly related ex- cepting by topographical contiguity (Fig. 732), the be- ginner makes dissections for the exposure of parts in their structural continuity; Figs. 681, 682, and 801. § 46. To facilitate discrimination of natural from arti- ficial surfaces, especially upon permanent preparations, incisions always follow straight lines and meet at angles rather than join by curves; see Figs. 708 and 733. § 47. Specimens that might be injured by falling upon a hard surface from the height of even a decimetre (four inches) are held during examination over a pad of cotton or a dish of alcohol, and carried from room to room in a vessel and not in the hand. § 48. Embryos and delicate brain preparations are dis- sected under alcohol, and sometimes pinned to a piece of 371 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. cork loaded with sheet-lead; see Fig. 734. Preparations including the medicommissure (Fig. 709) are supported upon cork while making and for exhibition. § 49. In brain dissection, as in surgery, the knife is made the last resort; blunt points and blowpipes are em- ployed as long as possible. When cutting is to be done the aphorism of Dr. Holmes is recalled: “ Let the eye go before the hand, and the mind before the eye.” § 50. Delicacy of manipulation is cultivated and a prompt check put to all forms of anatomical Philistinism, whether in word or deed; the student is urged to prac- tise self-control, to restrain what Hyrtl calls the “furor secandi,” and never touch his specimen except for a good and sufficient reason. From the ecclesiastical standpoint, perhaps, the “laying on of hands” cannot be overdone, but in practical anatomy its excess is likely to prove the reverse of a blessing. These cautions are called for in Fig. 978.—Base or Ventral Aspect of the Sheep’s Brain with the Eyes Attached. Slightly enlarged. 1, Frontal portion of pallium mesad of olfactory bulb; 3, precribrum (‘‘anterior perforated space’’) just cephalad of the optic tract; 4, tip of temporal lobe overhanging optic tract ;* 5, root of trifacial (trigeminus or fifth craniai nerve): 6, opposite the narrow band of fibres crossing the crus, called by von Gudden “tractus peduncularis transversus,” cimbia by the Ass’n Amer. Anatomists ; 7, trapezium, concealed in man by the overhanging margin of the pons; 8, pyramid. Compare Figs. 672 and 689, pp. 143 and 154. Most of the nerve roots and many other details are (From ‘* Physiology Practicums.”’) row portion of olfactory tract (compare Fig. 688, p. 153); omitted. respect to the dissection of muscles, etc., to which the examination of the brain is as watchmaking to the wield- ing of hammer and tongs. § 51. All specimens are numbered as soon as received (§ 146), and the essential data preserved in the form of a card catalogue (§ 151). § 52. From the beginning students are required to make outline drawings, accurate if not artistic, and clear rather than shaded. § 58. Preliminary Work upon Animal Brains.—I can- not too strongly emphasize the view indicated in § 7 as 372 to the desirability of gaining from the comparatively in- expensive brains of lower mammals the manipulative dexterity and the familiarity with parts and their names so essential to making the best possible use of the pre- cious and costly brain of man. The two particularly recommended are of the sheep and the domestic cat; but the methods of removal and dissection appropriate for the latter may be applied to the rabbit and to small dogs, while larger dogs, the pig, the calf, and cattle may be dealt with substantially as indicated for the sheep. § 54. Removal of the Sheep’s Brain.—Unless already familiar with the general form and size of the organ it will be well to consult the representations of it on pp. 158, 178, 208, 209, 372, 374, 382, ora plaster cast such as may be had for a small sum at Ward’s Natural History Establishment, Rochester, N. Y. The mode of extrac- tion recommended was devised by Prof. P. A. Fish while instructor in my depart- ment in 1890, and is indicated, perhaps sufficiently, in Figs. 979 and 980. In brief, the cra- nium, containing the brain, is removed from the facial por- tion of the head by sawing in a plane coinciding with the ventral margins of the orbits and of the foramen magnum. The corners of the cranium are then sawn off and the brain ex- posed with nippers, beginning with the base. The nerve roots must be divided with the scissors. The dura must be divided about the hypophysis, and special pains taken to dis- lodge the olfactory bulbs from their fossee (§ 60, H). § 55. Instruments Required. —In addition to a stout knife, coarse forceps, and coarse curved scissors, strong nip- pers, and a medium-sized saw, the sawing will be easier and more expeditious if the head can rest against the edge of a board or in an oblique sort of miter-box: the form of this will readily suggest itself if the operation is repeated sey- eral times. § 56. Removal of the Cat’s Brain.—The following direc- tions are condensed and modi- fied from W. and G., pp.'423- 432. The brain only is con- sidered here and other parts are disregarded. Consult Figs. 682 and 686, pp. 149 and 151. The head is supposed to have been cut off. A. Instruments and Materi- als,—Arthrotome or stout scal- pel; coarse curved scissors and forceps; nippers of medium size. B. Removing the Skin. — With arthrotome or knife, di- vide the dorsal skin from near the nose to the caudal free margin. Remove the skin in the easiest way by putting the connective tissue on the stretch and cutting. Note the third eyelid or plica at the mesal angle, represented in man by a vestigial fold of mucosa. C. Removing the Mandible.—Dissect the temporal mus- cles from. the side of the cranium. Divide the zygoma with the nippers, its cephalic end by pushing a point 2, nar- * According to the view expressed on p. 209, § 371, the part marked 3 and the olfactory tract cephalad of it, are parts of the rhinencephal, while 4 and 6 are portions of the prosencephal. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ventrad, between it and the eyeball; its caudal end by pushing a point ventrad from the temporal fossa just cephalad of the auditory meatus. The mandible may now be moved up and down so as to indicate the location Fic. 979.—Left Side of Head of Sheep, Skinned. orbit O, and of the occipital condyles V. See § 54. of the joint; open this with the arthrotome; cut the soft parts about the mouth and throat and remove the mandi- ble together with the larynx, esophagus, etc. D. Remove the eyes by cutting the muscles, etc., with curved scissors. The white cylindric optic nerve at the bottom of the orbit is to be cut, not torn. E. Remove the cervical muscles by cutting lengthwise at either side of the cervical spines and then dissecting off the muscles. With the nippers cut off the spines; the atlas, of course, has none. Note the occipital crest for attachment of the strong musclés. F. Opening the Cranium.—Rest the head on either side. Apply the nippers at nearly right angles to the convex temporal region and “gnaw” through the cranium till the dura is reached, taking care not to plunge the points into the brain. The dura may be recognized by tough- ness and non-vascularity. It may adhere so closely to the bone as to come off with it, but should be left on the brain for the present if possible. Continue to expose the brain by nipping off successive fragments, by break- ing rather than by direct cutting. Before crossing the me- son expose the entire lateral aspect of the cerebrum and continue cautiously cephalad to the olfactory bulb. G. The Cerebellum.—Expose this from the same side. Between it and the cerebrum is a bony tentorium, which may be removed without injuring the brain if the nippers are introduced sidewise for about 1 cm. between the cerebellum and the cerebrum at the meson and just above the meatus. Continue caudad by nipping the sides of the atlas and axis so as to expose a portion of the myel. H. The other haif of the brain is most easily exposed by passing the nippers-point between the cranium and dura at the meson, and nipping or breaking off fragments - as before; but constant care will now be needed lest the fingers crush the side already exposed. I. Remove the mazilla by cutting with the nippers across the spongy ethmoid region about 1 cm. cephalad of the cerebrum, and then dividing the base and sides of the maxillary bone. The olfactory bulbs may now be exposed; at the first trial one or both is almost sure to be torn or crushed. J. Remove the base of the cranium, in fragments, using both nippers and coarse scissors cautiously until at about the middle of the cerebrum is seen the chiasma; try to expose the optic nerves for a few millimetres; avoid pull- ing upon them lest the brain be torn. The hypophysis lies just caudad and is to be saved if possible. K. Hold the specimen, ventral side up, the brain just (From my paper, 1896, g.) Along the line A-B the butcher may cut with saw or cleaver so as to remove most of the face; it extends from the angle of the jaw to a point about mid- way between the nose and the prominence of the head between the eyes. The rest of the face is then to be separated from the cranium by sawing some- what accurately along the line A-C, intersecting the ventral margins of the Brain, Brain, resting in a dish of brine. By raising the base of the cranium carefully there may be recognized successively the pairs of cranial nerves; each is* to be cut with the scissors as far as possible from the brain. Continue caudad as far as the myel was exposed; then divide the myel. L. The ventral dura has probably been re- moved with the base of the cranium. Remove the remainder as convenient, noting the mesal fold between the two hemicerebrums, constitut- ing the falx, and its connection with the layers of dura between which was the bony tentorium. § 57. Hndymal Continuity and Celian Cireum- scription.—A detailed account of these features of the mesal cavities of the human brain occurs on pp. 151-152 in connection with Fig. 687. In connection with it, and preferably as preliminary to it, the mesal aspect of the sheep’s brain may be studied by the aid of Fig. 981. § 58. Transections.—Before transecting or dis- secting the human brain it is well to make and study carefully transections of the sheep’s brain at levels such as are indicated in Fig. 981; and at others as preferred. They are more instruc- tive in some respects if the alba and cinerea are differentiated as by some chromic acid com- pound (§§ 84-86). § 59. Fig. 981 illustrates: A. The general similarity to the corresponding aspect of the human brain as shown on pp. 141, 189, and 213. B. The slighter cranial flexure; p. 142, § 36. C. The smaller relative size of the cerebrum, permit- ting the cerebellum and even the olfactory bulbs to ap- pear in a dorsal view of the organ; p. 144, § 40. D. The large size of the medicommissure; p. 166, § 151. E. The distinctness of the crista in the adult sheep; p. 208, § 366. F. The non-extension of the callosal rostrum, as a copula, to join the terma, as in man and the chimpanzee, and the consequent closure of the narrow pseudocele by the pia only; p. 184, § 228. G. The absence, as in mammals generally, of small foliums upon the lingula; p. 160, § 119. H. The absence, as in mammals generally, of a meta- pore (foramen of Magendie); p. 154, § 78. I. The completeness of the endymal continuity or celian circumscription; p. 151, § 63. J. The possibility of transecting several of the seg- ments without cutting others. A-—A crosses the myel; nasal bone maxilla nasal septum eye zygoma coronoid process : jmenaiule fossa (or condyloid process) basioccipital - oblongata Fig. 980:—Ventral or Cut Surface of the Cranium as Separated from the Face Along the Line A-C (Fig. 979). If the parts outside the lines D-E and F-G are sawn off, the brain may be exposed by removing with the nippers the base and one or both sides of the cranium. B-B the postoblongata, metencephal, overhung by the cerebellum; C-C, the epencephal (cerebellum, preoblon- gata, and pons); D-D, the mesencephal (crura and quad- 373 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. rigeminum); E-E, the diencephal (tuber, medicommis- sure, thalami, etc.), overhung by the cerebrum; HY; the prosencephal (cerebrum) just cephalad of the chiasma DIACOELE” tuber Fig. 981.—Mesal Aspect of the Right Half of the Sheep’s Brain; xX 2. (From “Physiology Practicums.’’) This figure is semi-schematic, cer- tain details being omitted for the sake of clearness, ¢.g., the divisions of the cerebellum, the vessels, and the meninges, arachnoid and pia. The cut edge of the pia, however, is represented by the line between the rostrum and the crista, The names of the cavi- albicans removal is done leisurely * and with care so as not to dis- tort form or rupture membranous connections. Secondly, the calva (calvaria or skull-cap) is divided sagittally 1 to -—.. Splenial fissure ae diatela habena , splenium 1 supracommissure tA ~" ae eg epiphysis METATELA ties, Diacale, etc., should be spelled Diacele, ete. The endyma lining the diatela is really continuous at each end with that of the adjacent parts. The lines A—A to G-G represent planes of instructive transections. G-G, the rhinencephal, at the junction of the olfactory bulb and tract (pp. 153, 178, 208, 209) overhung by the cerebrum. § 60. Removing the Adult Human Brain.*—The method here recommended and described differs from those some- times employed in three respects: First, since the brainis Fig. 982.—Head-Rest Devised by Stroud, in Use. 1900, b.) A, Baseboard; B, upright board; D, chin-rest; E, lateral iron bar. For details see Figs. 988-989, and §§ 142-143. 1-1, Reflect- ed portions of the scalp. (From his paper, not to be sliced or cut into small pieces for histologic examination, but preserved entire or in large divisions for morphologic investigation and demonstration, the * See also the articles Autopsies and Brain, Surgery of. 374 See § 58, J. 2cm. from the meson and removed in two pieces. Thirdly, the subject lies upon the belly with the head supported and steadied in the “head-rest” devised by Dr. Stroud (Figs. 982, 988). A. Instruments and Matertals.—In the absence of a well-equipped post-mortem case (see the article Aw- topstes) the following should be provided: Scalpel, me- dium size; arthrotome (Fig. 985) or a similar stout knife; syringotome (Fig. 985); probe-pointed bistoury (§ 138); coarse scissors and forceps; fine scissors and forceps; tracer; bone-chisel (§ 139); mallet or hammer; strong hook, for catching on the divided margin of the calva and dislodging it;+ saw (§ 140); drill or awl or wire nail; wire and cutting pliers (p. 385); | surgeon’s needles and silk; absorbent cotton; common cotton; plaster of Paris; towels and Japanese napkins; scales; several pans of water and of brine, one large enough for medisection of the cerebrum. The beginner will do well to have at hand for consultation a hardened brain and a preparation of the dural folds (falx and tentorium) or models or good figures of the same (Fig. 800). B. Dividing the Scalp.—Between the roots of the ears carry a cord over the highest region of the head. Wet the hair along this line over a zone 2-3 cm. wide.§ With * Commonly an hour and a half is allowed for the operation ; but on one occasion, in an emergency, With the aid of a single assistant, Dr. Stroud removed a brain and made the head presentable for waiting friends within forty minutes. + In the absence of one made for the purpose it may be made from stiff wire; some large pocket knives have a hook of suitable size and strength. t¢ The pliers used by the linemen of the telegraph and telephone answer admirably for both cutting and twisting. ‘ § This and some other details presuppose that the body may be viewed by friends or that there are other reasons for the minimum of disfigurement. Under certain circumstances they may be disre- garded, although I think it well to maintain an almost esthetic and artistic attitude toward all dealings with the human brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, a narrow scalpel handle or any convenient instrument part the hair along the cord so that none remains cross- ing the line of incision. Mark the proposed line with a soft pencil or a fine point, and remove the cord. Insert a scalpel point at the top of the head with the edge away From the head and cut toward either ear along the chosen line, avoiding deflections and the division of hairs. Di- varicate the edges and repeat the incision if necessary so as to divide fat and connective tissue to the periosteum, or, at the sides, over the ears, to the firm fascia covering the thin (temporalis) muscle in that region. C. Reflecting the Scalp.—Dissect up the scalp at either side and reflect it over the neck and the face to a level, if possible, a trifle lower than the first incision between the roots of the ears. Before reflecting the frontal portion it may be well to cover the face with a pad of cetton to protect the features from undue pressure. D. Circular Division of the Cranium.—Tie a cord around the head just dorsad of the ears, the frontal por- tion passing about 15 mm. from the brows; mark this line with a pen, or cut the periosteum to the bone. If the fresh calva is to be secured in place after the extrac- tion of the brain, leave the fibrous cephalic and caudal margins of the temporal muscles for the stitches to be taken in; otherwise these muscles may be removed en- tirely. In sawing,* three points are to be observed: (1) The thicker frontal and occipital regions should be taken first ; (2) at four places, preferably what might be called the four corners of the cranium, the bone is not to be divided completely until the calva has been sagittally divided (§ 66); (3) if the ectal features of the brain are to be pre- served intact, a sectioned cranium should be consulted in order to estimate the thickness at variable points, and frequent trials should be made by pushing a point, like the probe end of the tracer, into the kerf (saw-cut) at the middle of that part of the convexity; when it can be pushed through, the sawing should proceed with care in each direction. E. Sagittal Division of the Calwa.—After the circular kerf has been completed, but before the calva has been loosened by the chisel,+ carry a cord from the brows to the occiput, over the head, at about 138 mm. (half an inch) from the meson; along this line cut or mark the periosteum, and saw completely through the bone. Then, with taps of the hammer upon the chisel, sever the remaining attachments of the smaller part of the calva along the circular kerf. Sometimes that piece will come off readily; if not, introduce the spatula in the temporal region, where the bone is thin, keep its point pressed against the bone and so detach the piece; in some cases the spatula must be introduced at other points, always with the minimum amount of pressure upon the brain. The mesal adhesions along the sinus are now directly accessible, and a sharp edge may be employed if neces- sary. The location of any other adhesions may commonly be inferred from what existed upon the first piece, and the removal of the larger side of the calva is completed without difficulty. F. The Dura.t—Unless it is desired to retain the calval dura entire the longitudinal sinus should be slit to let out the blood. Commonly, notwithstanding all precau-_ .tions, the saw has cut the dura at some point. There— or at any other point—commence with the scissors or probe-pointed bistoury, and cut the dura along a line about 2 cm. from the margin of the cranium and turn * Most of the sawing should be done by an assistant, that the chief ‘may better accomplish the later operations. + If the conditions are such that the calva must be kept entire there seems to be no other way than to remove it by pulling upon either the frontal or occipital edge with a hook as is commonly done at post- mortems; but this is almost certain to tear the brain or its telas or plexuses so as to render them unsuited for morphological elucidations. t Space will not permit detailed directions for removing the brain in the dura; suffice to say that with care and patience and anatomical knowledge it may be accomplished so that only a small part of the dura is absent from the central region of the base. For the safe ‘handling of the brain and for alinjection purposes even the dorsal half of the durais worthsaving. See pp. 171 and 213, Figs. 720 and 801. it outward so as to protect the delicate brain from the sharp or rough edges of the cranium.* Lift the sides of the dura in turn, cutting with scissors any vessels or fibrous connections between the dura and the cerebrum; near the meson there are several veins entering the longi- tudinal sinus. Unless the entire calval dura is to be preserved the two sides may now be cut away along the margins of the sinus. G. The Falx.—On Figs. 800, 801, and 804 (pp. 212, 218, 215) note its form and its relations to the crista galli, the tentorium, and the callosum. Ina good light divari- cate the frontal lobes so as to expose the narrow cephalic portion of the falx and transect it with scissors. Lift the end slowly, dividing membranous and vascular attach- ments as they appear; at its wide occipital end there will be need of especial care lest the traction dislocate the im- portant relations of parts about the splenium. The wide end of the falx may now be divided along its attachment to the tentorium. H. Freeing the Ventral Attachments of the Cerebrum.— These are (a) the entocarotid arteries (“internal carotids,” Fig. 803, p. 214) and some smaller vessels and fibrous bands; (0) the optic nerves (Fig. 672, p. 143), the hy poph- ysis (Fig. 689, p. 154), and the filamentary olfactory nerves passing from the ventral side of the bulb (Fig. 672, p. 148) through the cribriform plates. Unless these filaments are divided the bulbs or their tracts are likely to be torn. The head should be tilted a little so as to per- mit some recession of the frontal lobes. Raise these and allow a good light to enter between them and the cranial floor. With the syringotome or other small curved in- strument, divide or tear the soft olfactory nerves as they enter the cribriform plate so as to free the bulbs; some- times it may be done most easily with fine curved scissors. The carotids are easily recognized at the sides of the chiasma and should be cut with the scissors. The optic nerves are tough and not apt to tear, but the slender infundibulum is very easily broken; hence, before dividing the nerves, it is well to cut the dura at the margins of the hypophysial (pituitary) fossa and so dislodge the hypophysis as completely as possible. When this is accomplished divide the optic nerves close to the cranium. Now tilt the head first to one side and then to the other so as to permit the division of some veins connecting the temporal region with the cranium. I. The remainder of the operation will differ according as the brain is to be removed entire or in two portions, cerebral and cerebellar. For most purposes the latter is preferable, and it is so much easier that the beginner is advised to adopt it until familiarity with the parts has been gained by experience. J. Transecting the Mesencephal.—Tilt the head so that the cerebrum tends to slidesomewhat cephalad. Lift the occipital lobes and with the scissors cut the vessels and connective tissue and membranes just caudad of the splenium (Fig. 801) so as to expose the gemina, the dorsal lobes of the mesencephal corresponding to the crura ventrad (Figs. 707, 708). This is the narrow region connecting the wider cerebellar mass with the still wider cerebral portion, and hence called sometimes the “isth- mus.” With the probe-pointed bistoury or sharp, narrow scalpel cut this just caudad of the epiphysis; the knife should point almost directly at the tip of the nose if the pons is to be wholly avoided. It is sometimes well to make two cuts, one from either side, directed slightly cephalad as well as mesad so as to avoid the curved mar- gin of the pons. The trochlearis and oculomotor nerves will probably be cut during the transection. If not, they are to be watched for and divided during the next step. The cerebrum may now be lifted out with both hands and weighed (§ 62) or otherwise dealt with as desired § 61). Re Tentorium.—This is to be cut, with the blunt- pointed bistoury or the coarse-curved scissors, along its * For this valuable suggestion I am indebted to Dr. Stroud. 375 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. attached periphery and removed entire, thus exposing the cephalic (“upper ”) aspect of the cerebellum (Fig. 700, p. 159). If the head is tilted a little to one side and the other, the fingers may be safely passed under the com- paratively firm pons so as to lift the whole mass and expose the remaining cranial nerves (Fig. 681, p. 154). When these and the vertebral arteries are divided (Fig. 808, p. 214) the myel itself may be cut well down in the spinal canal. Lastly, afterreplacing the parts and tilting the head cephalad, may be divided the attachment of the arachnoid about the foramen magnum, and the mass may now be removed. It is advantageously kept entire till hardened, but the cerebrum is more easily dealt with and commonly more instructive if medisected at once. § 61. Medisecting the Fresh Cerebrum.—This is to be done with a large knife, thin and very sharp. The mass should rest in a wide dish of brine and be steadied but not actually supported by cotton at the sides. The frontal lobes are held closely together by the arachnoid along a line corresponding with the ventral (concave) margin of the falx (Figs. 800 and 801, pp. 212, 218). This arachnoid must be torn or carefully divided so as to permit the slight divarication of the hemicerebrums and the exposure of the mesal zone of the callosum, recogniz- able from its white color at the bottom of the intercerebral fissure. If there are special reasons for obtaining an accurate medisection of the callosum itself or of the pseudocele (Fig. 756, p. 189) the section may begin with the callosum, preferably the genu or cephalic curvature. Commonly, however, I have found the delicate terma and medicommissure more perfectly preserved when the cerebrum rests upon its dorsum and the chiasma is divided first. In either case the knife should be constantly irri- ated. § 62. Weighing the Fresh Brain.—This may be done in any of three ways. A. With an animal of moderate size, or a child, ora separated head, the weight of the brain represents the loss of weight of the animal, child, or head after its re- moval. B. A vessel partly full of water, salt solution, or brine, is balanced upon the scales;* the brain is lifted from the liquid in which it has been, in the hollowed hands; they and the brain are rinsed with water, and the brain is transferred to the vessel on the scales. If the dura re- mains the weighing cannot be accurate, even by deduct- ing its weight when removed. C. After recording the weight required to balance the added brain, then—having first wet the hands with a liquid identical in composition with that in which the brain is immersed—remove the brain and record the loss of weight. Theoretically it should be the same as had to be added before; practically there is usually some dif- ference, and the average of the two may be taken as representing the true weight. § 68. Determining the Volume of a Brain.—This is done, as with any other mass, in either of two ways. A. Into a vessel of accurately known capacity pour a given volume of liquid; dip the hands in the same, and transfer to it the brain; then from a graduated vessel add enough more of the liquid to fill the first vessel. The difference between the total capacity of the vessel and the sum of the two volumes of liquid introduced repre- sents the volume of the brain. B. Set a vessel in a deep pan, dish, or pail. With any liquid (salt solution, water, or alcohol and water) that is lighter than the brain, fill the vessel just to the brim. Let the brain into it gradually; the overflow will repre- sent its volume. Obviously a combination of the two methods is most satisfactory. § 64. Dividing Nerves and Vessels.—As a rule this should be done with the scissors, not so much to avoid *Some trouble will be avoided if, after the pan of liquid has been counterpoised upon the scales by an approximately equal weight, say 500 or 1,000 or 1,500 gm., the exact balancing is accomplished by removing or adding liquid with a syringe. 376 blunting the scalpels by contact with bone as to avoid the almost inevitable traction and breakage of delicate or important attachments. § 65. Closing Divided Vessels.—This may be desirable either to prevent the disfigurement of the body or cloth- ing by blood, or to permit the injection of the general vascular system. In the latter case, unless the divided vertebrals and carotids can be tied or caught with se77es- jines, the regions in which they open may be filled with plaster of Paris. In the former case, plugs of absorbent eotton may be pushed into the spinal canal and the vas- cular orifices at the base of the skull, and the cranium then filled firmly with the cotton so as to be compressed and crowded down by the calva. § 66. Reuniting the Divided Calva.—lf necessary, at once, or at any time, the two parts of the calva may be united by wires, or even cords, passed through holes at the middle and at each end; such holes may be made with a drill, awl, or wire nail. § 67. Reattaching the Calua.—Whether reunited or not the two pieces of the calva may be secured by wires through holes at each of the four “corners” (§ 60, D). Further stability is gained by stitching the divided edges of the temporal fascia. § 68. Sewing up the Scalp.—A knot should be tied at the end of the silk and the needle introduced at the root of the ear, at first ecto-entad (from the surface inward), afterward ento-ectad (from within outward); the stitches not too long, and not entangling the hair. Even if the concealment’ of disfigurement is not essential the opera- tion should be neatly done unless there are special reasons for unusual haste. § 69. Other Methods of Removing the Adult Brain.* § 70. By Removal of the Occipital Region of the Cra- nium.—At the meeting of the American Neurological Association, June 22d, 1883, as reported in its Transac- tions, p. 84, as reprinted from the Jowrnal of Nervous and Mental Disease, July, 1883, Dr. Spitzka described as follows a method which, he informs the writer, he has. known to be employed by some German anatomists. The writer has not tested this method personally, but is disposed to regard it as better adapted to pathological than to anatomical purposes, and as such entitled to be considered in connection with the usual method, and with that described on pp. 789-791 of Vol. V. of the first. edition of the REFERENCE HANDBOOK: “The scalp is divided in the median line, beginning a little in front of the coronal suture, and extending down the neck. If it is desired to remove the spinal cord the incision is extended to the lumbo-sacral region. Two lateral flaps are formed in the head region, the soft parts being peeled from the dorsal aspect of the cervical verte- bra and the posterior half of the skull. A circular in- cision is made [with the saw] in the skull, behind the ears, and completely encircling it down to the foramen magnum, care being taken not to injure the connection between the articular processes of the atlas and the oc- cipital condyles; the posterior half of the skull is removed exactly as the calvarium ordinarily is, by taps of a chisel; sometimes a rongeur forceps suffices to complete the division near the foramen magnum. The adhesion about, the lateral [and longitudinal] sinus and torcular Hero- phili can be readily overcome by a home-made apparatus like the knife [spatula, or round-pointed knife, curved flatwise] shown by Professor Wilder. The advantages of this method are: 1, The spinal cord and brain can be demonstrated in continuo; 2, the critical operation of lifting the hemispheres and gouging out or injuring the cerebellum in dividing the tentorium is obviated; 3, the nerves and arachnoidal laminze at the base may be divided without allowing the brain to drag by its own weight. These nerves are divided from behind forward. As soon as the chiasm is divided, the skull is inclined a little, and the brain allowed to fall into the hands of the operator by its own weight, it being completely separated, except where the olfactory filaments pass through the ethmoid; * See the article Autopsies. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. but these yield readily, and I have gotten the olfactory bulb intact as often by this as the other method. The removal accomplished, the occipital segment is riveted back, and a stick of wood inserted in the spinal canal and extending to. the cranial interior restores the strength to the head support, impaired by the breaking up of part of the vertebral attachments.” § 71. The method of Féré (as briefly described in a paper “ Procedé de coupe du crane,” Soc. Anat. de Paris Bulletin, ii., 206-207, March, 1877) is by a circular incision very low down from the eyebrows ventrad of the auditory meatus to a point between the foramen magnum and the dorsal arch of the atlas. This, if successful, would un- cover the brain very fully and permit its replacement in the calva after extraction: but it seems inevitable that the petrous bones should give trouble as well as be them- selves destroyed. § 72. Removing the Brain from Late Fetuses, Still-Borns, or Young Children.—This is most conveniently done if the cranium and maxillary region are first cut away from the neck and mandible by cutting with coarse-curved scissors from the corners of the mouth to the nape of the neck. The mass thus obtained is compact and may stand upright in liquid. A. Instruments and materials required. Coarse for- ceps; coarse-curved scissors for bone; another sharp pair for soft parts: tracer (Fig. 985): nippers (Fig. 986); large scalpel; narrow-bladed scalpel, preferably a probe- pointed bistoury; four vessels, holding about two litres each; twoof water; one of preservative; one of saturated brine; if the weight of the brain is to be ascertained (§ 62) the body should be weighed before the head is re- moved, and there should be provided a fifth vessel of normal salt solution (15 to 2,000). B. The scalp should be removed completely, together with the ears, and temporal musclesas faras the zy gomas. C. Cranium and dura. In young subjects these ad- here closely; hence, contrary to what is recommended with adults, they should be removed together in pieces. With the tracer-point lift the united pericranium (ectal periosteum) and dura near the left margin of the prefon- tanel (p. 212, § 388), and with the scissors or scalpel slit the tough membrane so as to expose a little of the brain. Grasp the cut edge with the forceps and with the scissors cut out a piece including pericranium, dura, and interven- ing area of parietal bone. Continue in this way, using the nippers when necessary, until the entire left hemicerebrum isexposed. More and more care will be required to avoid injuring the delicate brain, either by the instruments or the cut edges of bone. Leaving the falx undisturbed, expose the right hemi- cerebrum in the same way, but with even more precau- tion and holding the head so that the left is more or less completely supported in the brine. D. Proceed then, mutatis mutandis, as directed for the adult (§ 60, G). & 73. Removing the Hemicerebrums Separately.—The following modification of the method just described has some advantages. After the exposure of the left hemi- cerebrum cut the veins as before. Let the head tilt to the left so as to expose the callosum. Divide it, as directed above, down to the base of :the skull; then the left half of the mesencephal; then the infundibulum and optic nerve; and finally dislodge the olfactory bulb. These last parts are then to be attended to first on the right side; the falx is easily removed, and the hemicere- brum comes out as soon as the veins are cut. The chief objection to this method is the danger of cutting the mesal aspect of one of the frontal lobes. § 74. When there are reasons for not mutilating the head, the removal of a child’s brain is much less con- venient. The body and legs should be wrapped up so as to be held and turned easily. Unless the child can be held by an assistant, it will be found convenient to let it rest in a sort of trough, like a piece of large roof-gutter; or to roll it up in a sheet of lead, which, upon pressure, will flatten so as to maintain any desired position. The tray or trough must be supported at a level with the rim Brain, Brain. of the vessel of brine, so that the head may hang over into it when desired. Needle and thread must be pro- vided for sewing up the scalp. § 75. Ventral Eaposure.—For some purposes, e.g., when the organ is tu be kept entire, or when the nerve- rogts are to be retained, the young brain may advantage- ously be exposed from the ventral side; this aspect should be first studied, as shown in Figs. 672 and 806; then the base of the cranium may be nipped away, or cut with the coarse scissors; it will be well to expose one side completely first, so that any errors detected may be avoided on the other. With care the hypophysis (Figs. 689 and 708) may be retained. This method is less applicable to adult brains, on ac- count of the thickness of the skull; this, however, may be softened by nitric acid (§ 127). On February 1st, 1884, the writer removed the cranium of a small monkey (Midas, No. 342) by means of a dental engine, working a small saw and a burr. It may be pre- dicted that in time the work now done laboriously with saw and nippers will be accomplished more neatly and expeditiously by some apparatus like the electro-osteo- tome of the late Dr. M. J. Roberts (Virginia Medical Monthly, March, 1887). § 76. Brains of the middle and later gestative periods and at term are most useful for the comprehension of the early and simple condition of the fissures and of the order of their appearance. The best results are obtained by their prompt removal as described in §§ 72-75, and hard- ening with some zinc-chloride mixture (§ 89). The arte- rial injection of such brains rarely preserves them well, and the gyres are commonly so pressed together as to interfere with both the removal of the pia and the recog- nition of their relations. § 77. Harly Fetal Brains, Two to Four Months.—Un- less one has acquired considerable skill in manipulating such delicate objects, these should be hardened in place by one of the following methods, or by a combination of them; a five-per-cent. solution of zinc chloride in alcohol is very effective with embryo brains: A. Injection of the preservative through the umbilical vein. B. Immersion; if alcohol, or the above solution, is used the specimen should be suspended in it. C. Injection of the preservative with a hypodermic syringe both into the body in general and into the cavities of the brain.* The cannula should be pushed through the scalp at the margin of the prefontanel (p. 212, § 388), obliquely latero-ventrad so as to traverse the thin parietes and enter the large frontal portion of the paracele (Figs. 667, 716, 747). The success of the injection is shown by the expansion of the opposite half of the head due to the passage of the liquid through the portas (“foramina of Monro”) into the corresponding paracele. The exposure of such brains must be done under or over alcohol; the cranium and dura must be divided together at each cut (§ 72, C). The operation is tedious, but the results are revelations, no matter how often performed ; no specimens. are more beautiful or instructive; see Figs. 667, 746, 748. § 78. Hydrocephalic brains, and those of fetuses be- tween the second and seventh month, are alinjected in place from the aorta or other artery, and also have the more or less abundant neurolymph replaced by strong al- cohol. This direct, entocelian alinjection is done as soon as possible after the arterial has begun; it is most con- veniently accomplished by making a slit at one margin of the prefontanel large enough to permit the introduc- tion of a cannula and the escape of liquid at itsside. The injection need not be continuous, and, of course, should not be under pressure, but may be repeated at intervals of an hour or two. § 79. When a hydrocephalic or fetal brain is wanted for a special object involving the integrity of the entire cerebrum or the complete distention of the metepenceph- * So far as the writer is aware, this was first done by Professor S. H. Gage, May 17th, 1892, upon specimen 2,947. 377 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. alic cavities, then the undesired region is cut away, the desired region left in the cranium, and the alcohol in- jected through the mesocele, continuously, in order to make up for the non-injection of the arteries. § 80. Removed embryo and hydrocephalous brains are relieved from pressure during hardeuing by inflating the cavities; Fig. 715. The buoyancy of even an adult normal brain is sometimes increased by injecting air into the arteries through a bulb syringe. § 81. Preservative Liquids.—Al\cohol is a perfect pre- servative, but it bleaches the cinerea, and in any mixture with water strong enough to be effective the brain sinks and becomes distorted. The specific gravity of the mix- ture may be increased by glycerin, zinc chloride, or other heavy soluble salts (§ 82-84). Strong alcohol may be ne jected into the cavities and blood-vessels of the brain ($$ 91- 108). $82. Alcohol and Glycerin.—One of my most perfect and instructive fetal brains (1,820; Fig. 751, p. 187) was first placed in equal parts of alcohol and glycerin; after two days half the mixture was replaced by alcohol; after two days more alcohol alone was used, and this was renewed ie the following. The mixture merits systematic trial. & 838. Alcohol and Zine Chloride.—A_ five-per-cent. solution of this salt in ordinary (ninety-five-per-cent.) alcohol is very effective with embryo and fetal brains, whether by injection or immersion. & 84. Ammonium Dichromate.—Our use of this has not been sufficiently extensive for a general statement, but, at the suggestion of Professor Gage, it was employed in association with alcohol very successfully in the prepa- ration of the specimen represented on pp. 176 and 184 (Figs. 732 and 744). In equal parts of alcohol and water the salt was dissolved in the portion of 2.5 gm. to the litre. In addition to the thorough hardening of the sub- stance and the unusually perfect maintenance of the membranous and plexal attachments, the color differentia- tion was sufficient, although the subsequent prolonged preservation in alcohol alone has nearly bleached the cinerea. This salt merits further trial in various com- binations. § 85. Potassium Dichromate.—This is the essential in- gredient of Miiller’s liquid (§ 86). Dr. Stroud has deter- mined that, at the temperature of 20° C. (68° F.), a saturated solution of potassium dichromate contains about ten per cent. of the salt; at boiling the per cent. is forty-four. His method of using it is to effect the solu- tion rapidly in boiling water; when cool, enough water is added to float the brain just below the surface. The specimens in this solution or in Miiller’s liquid should be kept in the dark, z.e., in metal pans with metal covers, or in a dark room. As soon as the brain is firm to the touch it may be soaked for a day in water and then in alcohol, at first about forty per cent., then stronger, until the alcohol ceases to be colored, after which it may be kept in al- cohol of not less than eighty per cent.* The alcohol that is so colored may be used for the same purpose with other brains, or for the storage of specimens not requiring it to be either colorless or very strong. § 86. Miller’s Liquid.—This consists of two parts of potassium dichromate and one part of sodium sulphate in one hundred parts of water. Beyond increasing the buoyancy of the liquid, the sodium sulphate seems to have no special value for either microscopic or macro- scopic purposes and is often omitted. Sufficient buoy- ancy may be attained by increasing the per cent. of the essential ingredient (§ 85). § 87. The Incompatibility of Alcohol with Potassium Dichromate.—A. chemist to whom the matter was sub- mitted states that when alcohol and potassium dichromate are mixed in any proportion the salt will be at least partially reduced, and there will also be formed, from the alcohol, various compounds, as acetic acid, acetic * The specimens may be more completely decolorized by absolute alcohol (W. C. Krauss), by hydrogen peroxide (Unna, Arch. ftir mokros. Andat., xXxx., 48, 1887), or by a one-per-cent. solution of chloral hydrate (Lee, ** Microtomist’s Vade Mecum”’). 378 aldehyde, etc. These processes take place in either the light or the dark, but more rapidly in the light. § 88. Zine-Glycerin Mixture.—After careful considera- tion of prior suggestions, and prolonged experimentation, P. A. Fish published (1898, p. 398; 1894, p. 101) the formula of a liquid which, “though not ideal in its effects, seems to answer the requirements of economy, fixation of the structural elements, differentiation of tissue, a minimum amount of distortion, firmness of texture, and rapidity of action. ~“The formula is as follows: Water. a. soi.cecisys pales oek een 400 c.c Ninety-five-per-cent. alcohol........... 400 c.c. GAY COPIN ovis foroiesdinta hae isiars oon 250 c.c. Zine Chloride@ iets sites) Jt ete eee 20 gm Sodium. chlorid@.< <5 cs:sitep «<0 nee 20 gm “The specific gravity of the mixture should be about 1.04, a little greater than that of the brain itself (1.038). The slightly greater density of the fluid is believed to be more advantageous than otherwise, since it buoys the brain until the tissue has begun to harden and can par- tially support its own weight. The pressure is nearly enough equal on all sides to prevent any noticeable change of form. It is recommended that the cavities of the brain be filled with the mixture (celinjected) and if practicable the blood-vessels also injected. After an im- mersion of about three days the specimen should be transferred to equal parts of the foregoing mixture and seventy-per-cent. alcohol for a week or more, where on account of the lesser specific gravity it should rest upon a bed of absorbent cotton; it is finally stored in ninety-per- cent. alcohol.” § 89. Zine-Formalin Mixture.—Two years later Fish published (1895, @ and 0) the results of two experiments with an agent then comparatively little known. Refer- ring to the zinc-glycerin liquid he says: “ Experiments with formalin (forty-per-cent. formic aldehyde) show that practically as good results may be obtained at less cost when the following mixture is employed: Waters isisc ee mesg hectibs Ree eee 2,000 c.c Formalings....: = << sects eee 50 c.c. Zin’ Chlorides cmigecisseee a cee eee 15 gm Sodium chlorides oa. -e.. eee 100 gm The brain is left in the mixture for a week or ten days (a longer stay is not detrimental); when practicable the cavities and blood-vessels are injected with the same to insure a more uniform hardening.” Respecting the subsequent treatment Dr. Fish writes me that he recommends a course slightly different from that indicated in the papers quoted. For storage, a five- per-cent. solution of formalin, ¢.e., 50 c.c. to 1,000 of water.* In this it may remain indefinitely if properly covered. For museum purposes it may be placed suc- cessively for a few days each in alcohol, 50, 70, 90, and 95 per cent. § 90. Saline Alcohol.—Dr. Stroud, the successor of Dr. Fish, continued experiments with the same important end in view and devised a liquid which dispenses with the irritating zinc chloride, combines the two liquid preservatives, alcohol and formalin, and overcomes the difficulty due to the slight solubility of the sodium chlo- ride in an alcoholic mixture by employing a somewhat larger portion of another salt, sodium acetate. The formula as published in 1896 is as follows: Sodium acetate... 2... assem ee eee 130 gm Sodium Chlorides «4.0. .eaeer oe nee 110 gm Formal [formalin] (forty-per-cent. formaldehy.de)ie= eee 20 c.c. Alcohol (ninety-five per cent.)........ 460 c.c. Water. ics S52 ceo ane eee 540 c.c. Dissolve the sodium acetate and the sodium chloride in the water. Cool and filter, then add the alcohol. With * As the formalin does not prevent the freezing of the water, cold must be guarded against. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, alcohol free of tax the cost is about fourteen cents per litre. For a human brain is required about 8 litres, 7.e., three times the above formula. For a sheep’s brain, about 400 c.c., or half the formula. Brains should remain in brine to soak out the blood for a time dependent on their size. They should remain in the saline alcohol for ten or fifteen days, but a longer period is not harmful. Then they may be transferred to increasing percentages of alcohol. During the last four years there have been prepared by the saline-alcohol scores of human brains and hun- dreds of brains of sheep and other animals, and it has proved wholly satisfactory for macroscopic purposes, whether for dissection or permanent preservation. The * structural and color distinctions between alba and cinerea are well maintained. § 91. Experiments are making with a saline-alcohol in which the components have a simpler ratio, and the results will be announced as soon as practicable. § 92. Hntocelian Injection.—To fill with a hardening and preservative liquid cavities surrounded by flexible walls would seem to be a natural device both for the better preservation of the mass and for the maintenance of the forms and relations of the cavities.* A small glass syringe may be employed for injecting preservative liquids into the brain cavities, either directly or by attaching a rubber tube and cannula. § 93. Seldom, if ever, excepting perhaps with very small or thin-walled specimens (e.g., the brain of Crypto- branchus shown on p. 170, Fig. 717) is a single or mo- mentary introduction of the preservative sufficient. § 94. Continuous Injection.—This involves, first, the elevation of the reservoir of preservative to a height (upon a shelf or at the end of a cord) sufficient to insure steady and adequate pressure; secondly, the avoidance of damage from the clogging or twisting of tubes or the overflow of the liquid that has escaped after traversing the vessels or the cavities. The various requirements may be met by simple arrangement of pinchcocks and flexible wire supports of copper or lead. § 95. Without conceding the existence of other natural orifices from the paraceles (lateral ventricles) (p. 171, Fig. 721), both human and animal brains present outlets for the escape of the injected liquid so as to obviate the danger of rupturing the thinner parietes under any pressure that might be required for filling the cavities. With animals the myelocele (central canal of the spinal cord) is pervious through life. With a cat, for example, where 4 cm. of the myel remained attached to the brain, alcohol injected into the diacele (third ventricle) with a syringe escaped from the myelocele in a stream 8 to 10 cm. long, although the orifice of exit was 42 mm. from the tip of the metacele and 66 from the place of injection. With human brains (excepting early stages when the myelocele would probably be sufficiently pervious) there is anample outlet at the metapore (foramen of Magendie), (p. 154, § 78). The same is the case with apes and some monkeys. Hence the cannula, instead of fitting loosely, may be tied into the infundibulum, or made large enough to fit it closely. In the latter case the cannula may need a rubber collar to prevent its entrance so far as to lacerate the medicommissure or parietes. This precaution may be rendered superfluous by using a cannula which is bent upon itself at a right angle, in the form of a capital letter L turned one quarter way around, thus, —; the shorter arm enters the orifice (for tying in the infundibulum a slight enlargement of the point is desirable); the longer rests upon the base of the brain and has attached to it *The method was first employed by me, as assistant to the late Prof. Louis Agassiz, at Nahant, Mass.,in July, 1867, for permanent preparations of great vascular sinuses in rays. Since that time it has been applied in the anatomical laboratory of Cornell University to the preparation and study of hollow organs of all kinds, stomach, cecum, heart, uterus, kidney, and brain. In 1880 I first learned that the in- jection of alcohol into hearts was advised in 1860 by Hyrtl, and in 1879 by Mojsisovics; the former ascribes the idea to William Hunter. I am not aware that injection of a preservative into the brain cavities was practised or suggested by any one prior to December 14th, 1881, when I employed it upon a child’s brain. the tube connected with the syringe or injection reservoir This tube should be short and slender; in the intervals of injecting it may be compressed, or plugged with a glass or cork. § 96. Entocelian injection, whether repeated or con- tinuous, may be accomplished from any artificial orifice. The most favorable place is the mesocele (aqueduct) after transection of the brain; the cannula may be selected so as to fit it closely. With the cerebellar portion of the brain the metapore would serve as the outlet; with the cerebral it might be necessary to tie the infundibulum to prevent too ready escape therefrom; with a small stream at a slight elevation above the brain it is probable that any excess would be provided for by oozing along the rima. § 97. Entocelian Alinjection per Luram.—Four points are to be kept in mind: (1) The smallness of the orifice (Fig. 672), which may be enlarged, if desired, with the probe or by clipping the infundibulum shorter; (2) the general dorso-caudal direction of the passage (Fig. 687) ; (8) the danger of wounding the parietes, and especially the medicommissure ; the cannula should therefore be short, the tube small and flexible, and the cannula pushed through a disc of rubber so as not to enter more than 1 cm.; (4) the weakness of the encephalic substance after death; hence no more pressure should be exerted than suffices to fill the cavities and cause a slight eleva- tion of the tips of the temporallobes. The alinjection can should be just above the level of the brain, and the can- nula fit loosely in the lura so that the excess of alcohol may escape. § 98. Combined Arterial and Entocelian Alinjection,— This very effectual method of preserving a brain removed in the dura for any macroscopic purpose was employed with the specimens shown in Fig. 720. A separate reser- voir must be used for the entocelian alcohol (§ 97), or the branch tube leading to the lura must be small and kept compressed so that—when the cavities are once filled— the flow will be very slight. $ 99. Arterial Injection of the Preservative.—This is somewhat fully described in &§ 101-108, and is exem- plified in Figs. 670 and 801. As compared with immer- sion it has the great advantages of rapidity and thorough- ness. Any preservative may be employed, and alcohol may be used at full strength. A low temperature is needless, and even perhaps undesirable. Barring a slight shrinkage, the natural conditions and relations are maintained. It must be admitted, however, that sometimes the gyres are somewhat crowded against each other, so that the pial folds are less readily and safely extracted, and the fissural relations less easily determined. This applies particularly to infant brains. § 100. This is not the occasion for a complete history of injection processes or for the presentation of claims to originality. The transmission of preservative liquids to the tissues by a constant pressure apparatus connected with the vessels by which blood reached the parts during life is really so simple as well as effectual that it is hard to account for its comparatively infrequent suggestion and adoption. Without previous acquaintance with what had been done by others,* on October 7th, 1888, with the co-operation of Prof. S. H. Gage, I began upon the body of a young chimpanzee (No. 265) an alinjection of the entire body, which was prolonged for ten days and was completely successful. In November, 1885, a man- atee (No. 844), 150 cm. long, was prepared in like man- ner. Allthe cats used by the general class in physiology are alinjected and packed away till wanted. Still-born children are commonly so preserved, and I recommend that, with alcohol obtained free of tax, all anatomical material in medical dissecting rooms be thus rendered * Arterial alinjection of the brain is named or implied by Ecker (‘Cerebral Convyolutions,’’ p. 45); by Mondino (Trans. Roy. Micros. Society, 1885, p. 904); by Foster and sto! 8 Pract. Physiology,” p 215) ; by Key and Retzius (“ Studien,”’ i 104) ; and by the eee of the tenth edition of ‘* Quain,”’ vol. iii., “Hig. 88. It was done in 1 for Marshall upon a Bushman (Philos. Trans., cliv., p. 501); the dates of its performance for Flower and Owen are mislaid. 379 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. innocuous, free from unpleasant odor, and fit for pro- longed and thorough examination. $101. Location of the Arteries.—Nearly opposite the hyoid bone, or the cephalic margin of the larynx, each common carotid divides into an ectocarotid (“external ”) and anentocarotid (“internal”). In the adult they differ little in size, but may be distinguished in that the ecto- carotid branches at once and lies farther ventrad, while the entocarotid continues unbranched to the cranium and is accompanied by the vagus nerve. If the neck was severed close to the head the two arteries may be dealt with independently. If at the level of the chin (as in the head shown in Fig. 670) the common carotid may be followed up between the mus- cles, using the tracer rather than the scalpel as much as possible. But if the neck is entire, and especially if it is to be kept so, the ectocarotid may be exposed as for sur- gical ligation by an incision along the ventral (“anterior ”) margin‘of the sternomastoid from the lobule of the ear. In any case the ligature must be applied close to the bifurcation of the common carotid or the superior thyroid artery may not be included. As to the vertebral artery, unless there are special reasons for not injuring the vertebre, the transverse process may be nipped away in order to expose the vessel. The cannula is to be inserted in one, and the other tied after the arteries have been cleared. Since the two arteries unite to form the basilar it makes no difference which has the cannula, excepting that there is some convenience in placing it and the carotid cannula on the same side (Fig. 808). § 102. Secwring the Cannulas.—Preferably one cannula is to be inserted in the carotid, whichever is the longer, and another in the vertebral of the same side. Each is to be very securely tied; if there is no shoulder at the cannula point, then tie also around the rubber tubing at its base. All the knots should be the so-called “sur- geon’s,” one end of the thread being passed through twice instead of once; W. and G., Fig. 41. § 103. Clearing the Vessels.—Inject “normal salt solu- tion” (sodium chloride, 15 gm.; water, 2 litres) into a vertebral and entocarotid artery (preferably on the same side) until the liquid runs clear from the other arteries. Place in the alinjection can about 5 litres of twenty- two-per-cent. alcohol, strained through absorbent cotton or filter paper; raise the can to about 1 metre. In connecting the tubes let all air bubbles escape. Small arteries that leak must be tied or secured with serres-fines. The liquid should escape in six to eight hours and be quite bloody. If the last of it is nearly free from blood, the strong alcohol may be used; if not, repeat, using half the quantity of twenty-two-per-cent. § 104. The strong (ninety-five-per-cent.) alcohol may now be used at the same ‘pressure; it will pass through at a rate varying from one-third to eight-tenths of a litre per hour, and be reduced to seventy-five or eighty per cent. At the end of the third day, and perhaps earlier, the strength of the alcohol will be but little reduced; the pressure may then be lessened by lowering the can to one-half the height. By the sixth day the loss in strength may be no more than three per cent., and the discolora- tion insignificant. The alinjection may then be discon- tinued, and the head medisected (§ 109) or otherwise pre- pared. If desired, a colored injection mass may be thrown into the arteries of either the face (ectocarotids) or the brain (entocarotids and vertebrals), or all. § 105. Turning the Head.—There are reasons for be- lieving that the position of a head under injection should be changed daily, in order that no one region of the cere- bral surface shall be more than twenty-four hours in close contact with the cranial wall. ; &§ 106. Repeated Alinjection.—It is probable that the injection of, say, 1 litre of ninety-five-per-cent. alcohol, morning, noon, and night, for a week would harden a brain very well, but accurate experiments on this point have not been made as yet under the writer’s observation. If it be tried especial care should be taken to exclude air bubbles (§ 107), to keep the brain wholly submerged or its base covered with a layer of absorbent cotton dipping 380 into the alcohol. Such injections may be made con- veniently with an ordinary rubber-bulb syringe. Re- peated injection will conduce to the preservation of the celian parietes and of the plexal attachments, but is less effectual than continuous for maintaining the size and form of the cavities. § 107. Exclusion of Air Bubbles during Arterial Injec- tion.—This is accomplished by letting the alcohol run until no bubbles appear either in the cannula or in a glass tube which is introduced near the can. The can itself should always be at a higher level than the adjoin- ing tube, especially when it is lowered for the introduc- tion of fresh alcohol, since bubbles are then most apt to be formed; on this account the tube should be of ample length. § 108. Hiltration.—Whatever liquid is to be injected~ into the encephalic vessels must be carefully filtered through filtering paper, or through absorbent cotton crowded into the pipe of a funnel. This necessity ap- plies to unused alcohol as well as to that which has al- ready passed through tissues. § 109. Medisection of the Head.*—Determine the plane of section by the following mesal points, some of which, of course, are subject to variation: (1) Interval between the central incisorsin each jaw; (2) dimpleat tip of nose; (8) occipital protuberance (inion); (4) myel; (5) vertebral centrum; (6) notch in cephalic margin of larynx; (7) dimple of chin; (8) middle of top of head. This last is ascertained by carrying a piece of inelastic cord over the top of the head, securing each end in an auditory meatus by crowding cotton in with it, and then finding the middle of the cord. At each mesal point make a short but deep incision. Knot one end of a cord long enough to surround the head and neck at the meson; place the knot entad of the central maxillary (“upper”) incisors, and carry it over the nose, head, neck, and chin, back to the mandibular incisors, between which it may be secured by a wedge or otherwise. With the arthrotome divide the scalp, etc., along one side of the cord. Remove the cord, and at the occipital convexity (about at the line from 7 in Fig. 670) bore a hole at the meson deep enough to permit a screw to be firmly fixed. § 110. Adjusting the Head.—Place the head in the saw- box and mark with a pencil the points where the bottom and one side are in contact with the occipital region and the vertex; at these points bore a hole in the kerf large enough to admit one of the screws. Replace the head in as nearly as possible the same position; pass the spatula through the kerf above the hole in the side opposite the vertex, and adjust the head so that the end of the spatula is in thecut inthe scalp. While steadied in that position pass the gimlet or awl through the hole and bore into the skull for a short distance, 8 to 5 mm.; insert the screw at this point. Repeat the operation for the occipital region. This screw should bring the head firmly against the bottom of the box. If it is necessary or desirable to remove the head in order to bore the holes, when the head is replaced the holes may be found by means of the probe end of the tracer. § 111. Packing.—Draw through the kerfs in the two sides a cord just large enough to fit tightly, and pull it down so that it coincides with the cut in the skin of the face. Pack the cotton first in the angle between the two screws; then under the neck, keeping the whole con- stantly adjusted by means of the thread and the kerf at. the neck side of the box. When firmly packed, pour over the cotton some water until no more is absorbed. § 112. Sawing.—Remove the cord from the kerf; insert. the saw so that the handle is close to the side of the box, and make the first few strokes by drawing only—ther * The following instruments and materials should be provided: Saw ($ 140) ; saw-box (§$ 141) ; scalpel, the handle of which is smoothly rounded ; small, narrow-bladed scalpel, arthrotome, and tracer: two. screws, slender rather than thick, and 5-8 mm. longer than the thick- ness of the side and bottom of the saw-box; gimlet to fit the screws; short, stout awl, medium size; spool of stout saddler’s thread ; spat- ula ; cotton, or cotton waste or tow or bits of cotton cloth, previously soaked in water and well squeezed, enough to fill the saw-box quite firmly ; large agate pans or other suitable vessels; jars and alcohol. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, —_——— ua eeoeoeoeoeoeoeoeoeoeoeseseseseseseseseseseaeseseaeseaseaoaoaoaon_ saw in the usual way; a fine stream of alcohol (any per cent. above forty-eight) should irrigate the blade during the entire operation. The back of the saw should be re- tained as long as possible, and screws not removed until nearly reached by the saw. Let a gentle stream of water flow over the sawn surfaces. § 118. Removal of Hither Half of the Hardened Brain.* —A. Remove the falx and falcula (fala cerebell’). At the base divide the infundibulum close to the tuber, leav- ing the hypophysis to be removed separately. Note the location of the optic nerve, and divide by carrying the scalpel point latero-cephalad from the infundibulum for 1 to 2.cm., close to the dura, lest the olfactory crus be injured. Dislodge the olfactory bulb with the syringo- tome, turn it just over the margin of the hemicerebrum, and secure it by a small pin at either side. B. Transection of the Hemicerebrum.—Recognize, if possible, the dorsal end of the central fissure, nearly dorsad of the splenium. Place a strip of paper or a cord across the hemicerebrum between points about 5 mm. caudad of the fissure and the splenium. The half-head should be in alcohol or the blade should be flooded. The vertex should be toward the operator. Note on the empty half-head the angle formed by the tentorium with the meson, or observe on the preparation in hand. Push the scalpel into the brain close to the tentorium, and with a gentle sawing movement carry its point as faras it will go; continue the movements dorsad, making sure that the broad edge of the haft of the scalpel does not bruise the brain. The completion of the transection is an- nounced by the loosening of the occipital region. Prob- ably the greatest difficulty will be the division of the ex- treme ventral part. 'To remove the occipital part, push the probe end of the tracer or avery narrow-bladed scalpel into the brain 10-12 mm. caudad of the section plane, near the tentorium and between two fissures; the direction should be dorso-laterad at an angle of 45°, thus nearly perpendicular to the ental surface of the cranium toward which it is pointing. Dislodge the tip of the occipital lobe by coaxing with the scalpel handle; lift the whole piece slightly with the inserted instrument; it will come out for a certain distance, and then be checked by veins, which may be divided with scissors. C. Mesencephalic Transection.—From Figs. 706 and 708 note that (1) the crusta projects considerably ventrad of the mesal cut surface and (2) that the greatest width of the crus is not more than 15mm. Hold the scalpel with the flat side at an angle of about thirty degrees with the meson, let the ink mark be at the ventral margin of the crus, and cut dorsad with sawing strokes. Place the specimen so that the depths of the incision are illumi- nated, and divide whatever may appear; the hemicere- brum will float up, and be readily removed if the dorsal margin be first disengaged and the prominence of the temporal lobe kept in mind. D. Removal of the Metepencephal.—If the tentorium is to be retained, divide it by cutting laterad from a point just caudad of the angle between the natural, curved margin and the cut, straight margin; it is more conve- nient to remove it entirely. The half-head may now be placed upon a tray and supported, or held by an assist- ant. Crowd the edge of the round scalpel handle be- tween the dura and the myel for 2-3 mm., beginning at whatever point a slight interval already exists, and con- tinue the separation by gentle, yet firm pressure; special difficulties will be encountered at and near the occipital foramen, requiring perhaps the scalpel edge. Do the same for the cerebellum and pons, keeping in mind the + The following instruments and materials should be provided: A pan to contain the half-head (about 11 X 4in.), half full of alcohol of forty-eight to fifty-six per cent., this strength sufficing to fioat the separated pieces so that they may be extricated without. injury (of course, water would do this, but would rapidly soften the brain); a large scalpel, the blade at least 5cem. long and the haft 1.5 to 2 cm. more—a round-pointed “shoe knife’’ will serve; a medium-sized scalpel, marked with ink across the blade on each side 15 mm. from thetip; syringotome. Unless oneis very familiar with the topography of the parts a model or preparation of the hemiencephal is desirable, also a hemicranium of the same side—if possible two, one dry, the other wet, with the falx, tentorium, etc. (Figs. 670, 800, 801). natural curvatures of the surfaces and the locations of the larger nerves, especially the trifacial, the auditory and facial. Specific directions are hardly needed or pos- sible for the rest of the operation. § 114. Arterial Alinjection of a Brain in the Dura.—If the dura has been retained, at three places upon each side, frontal, temporal, and cerebellar (or occipital if the metepencephal has been removed), pin to the dura pieces of broad, stout tape (or strips of cloth 2 to 8 cm. wide) 10 to 15cm. long. In place of pins there may be used garment-clasps with serrated edges. § 115. For temporary purposes, e.g., examination of the base, preparation for injection, and the single injec- tion of a mass, etc., the brain, supported as directed in $§ 18-19, may be steadied and raised or lowered as re- quired, within any vessel of appropriate size. If of wood, the strips of cloth may be secured by tacks (artists’ “thumb tacks” are most convenient); if of glass or metal then an elastic band (e.g., a rubber ring from a jar, or an elastic tape) may be stretched about the rim and the strips passed under it. The vessels must be washed out (§ 108), and the small arteries tied or secured with serres-fines. § 116. Dry Preparations.—The methods of making these have been considered by Fish, who has also devised improvements. The following abstracts are largely de- rived from his papers, 1898, 1894, and 1897. § 117. Fish’s Improved Castor-oil Method.—The value of this is attested by Figs. 983 and 984, and by numerous excellent preparations in the museum of Cornell Uni- versity, brains, infant limbs, and entire small animals. “The essential factor is the complete dehydration of the specimen.” If originally hardened in any other than an alcoholic mixture it is placed successively for at least one week each, in fifty-per-cent. alcohol, seventy, eighty, and ninety-five percent. If carried through too hurriedly there will be more shrinkage. It is then placed in oil of turpentine until translucent, the time required varying according to the size of the specimen. The superfluous turpentine is then allowed to drain off for a few hours and the specimen is placed in castor oil. Here it may remain indefinitely or until all the tissues are thoroughly infiltrated. Draining off the superfluous oil requires a day or two and the specimen then receives a coat of an FIG. 983.—Right Side of the Brain of a Monkey, Macacus cyno- molgus, Prepared by the Castor-Oil Method. x1. (From Fish, 1893.) alcoholic solution of white shellac with a camel’s-hair brush. This is repeated at short intervals until the sur- face is firm and glossy. § 118. Laskowsky’s method is here translated from the abstract in the Newrologisches Centralblatt, vi., 841-342: A. Rinse the fresh specimen in water to remove blood. B. Place in a mixture of water, 100 parts; alcohol (ninety-five-per-cent.), 20 parts; boric acid, 5 parts; let it remain in a cool place [for at least three days; time not given]. C. Remove the pia. D. In a saturated solution of zinc chloride in alcohol let the brain remain five or six days; the bottom of the vessel should be covered with cotton. E. For fifteen to twenty days soak in a mixture of glycerin, 100 parts; alcohol, 20 parts; carbolic acid, 5 parts; boric acid, 5 parts. 381 Brain. Brain, F. Let it dry i in the air, protected from dust. The specimen is claimed to retain its natural volume, distinction of color, and elasticity. & 119. A temporary dry preparation for demonstrative purposes has been recommended by Lenhossek (Anat. Anzeiger, 1887, ii., 8-17; also Amer. Nat., xxii., 858-859). A thoroughly hardened alcoholic specimen, W hen needed Fic. 984.—Transection of the Brain of a Sheep, Prepared by the Castor-Oil Method, and Exhibiting the Differentiation of the Alba and Cinerea. 1. (From Fish, 1893.) for demonstration, is dried in soft linen for absorbent cotton], and coated with a thin layer of celloidin with a soft brush. The celloidin dries in a few minutes, form- ing a thin and transparent yet tough membrane. After two hours’ exposure the brain will begin to shrink and should be returned to alcohol. & 120. Starch-Injection Miatwre.—Of the mixture first proposed by Pansch, the following modification has been devised by 8S. H. Gage and the writer: Dry starch pow derssteen creme cere aie 100 c.c. Chioral hydrate se cmachi ects seeker 10 gm Watery eternal? 5 restos te incre mis eters one 50 c.¢. Alcohol (ninety-five per cent.)......... 50 ¢c.c Gly cerin'yetme as tee ou tein a tetas etere 29 ¢.c Coloring matter. After thoroughly mixing the mass it should be filtered _ through one or two thicknesses of wet cheese cloth. To prev ent the starch from settling, the cloth should be tilted from side to side or the mass may he stirred during the filtration. If the mass is not freshly prepared for every injection, the stock mass should be filtered occasionally to remove hair or any other object that might clog the cannula. Among the colors that are available, probably ver- milion, red lead, ultramarine, Berlin blue, chrome orange, yellow, or green, is preferable. § 121. A Fine, Gelatin Injection-Mass.—The follow- ing ingredients represent about 2 litres, enough for a human brain; gelatin may be used instead of the glue, and no egg would then be needed, but it costs three or four times as much: Best clear glue, 200 gm. (about 7 ounces); carmine, 20 gm. (about 0.7 ounce); glycerin, 240 ¢.c. (about 8 fluidounces); alcohol, 80 c.c.'(about 3 fluidounces); strong ammonia, 30 c.c. (about 1 fluid- ounce); acetic acid (50 per cent.), 80 ¢.c. (about 1 fluid- ounce); one egg. Grind the carmine to a paste with a little water; mix the ammonia with 250 c.c. (about 8 fluidounces) of water, add the carmine paste, and filter through filter paper. Place the glue in a clean dish and cover with cold water; after two or three hours pour off the unabsorbed water, and melt the softened glue. ‘Beat the white of an egg well and mix it with the clue. Heat until it begins to bubble, then filter through fine flannel. Add the coloring liquid to the glue while warm. WNeu- tralize the ammonia by stirring in the acid, a little at a time, until there is no distinct odor of either the acid or the ammonia. Until one has had considerable experience it will be necessary to close the ammonia and acid vials, let a current of air sweep over the mixture, and then de- termine the presence of the odor. Blue litmus paper may be used until there is no distinct coloration of the band 382 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. formed by absorption just above the line made by the mass itself. Mix the alcohol and glycerin and add to the mass. Unless, as with a freshly killed animal, the injec- tion is made before the body has cooled, the part to be injected must be heated, in water, to 40° C. (about 105° F-.). § 122. Alcohol.—Unless otherwise specified, the alcohol mentioned in this article is of the usual str ength, ninety- five per cent. The admixture of alcohol with water in the following proportions gives various percentages: Alcohol 6, water 1 = 84 per cent.; 5: 1 = 82; 4:1 = 78; 321 = 76: 221 = 67; 1.5.21 = 62% 125% G0 eee Ei 1:1.5 =42a 12) soon OE ei at 45; 6s == 18; g 123. Obtaining valoohet Free of Tax for Scientific Pur- poses.—Blank forms for this and all the information re- quired may be obtained from collectors or deputy col- lectors of United States Revenue or from manufacturers of alcohol. See U. 8. Revised Statutes, Section 3297, Treas- ury Circulars of July 2d, 1886, and March 26th, 1889, and New York Medical Journal, March 30th, 1889. § 124. The surface of a fresh brain is never exposed to: strong alcohol without a previous wetting with salt solu- tion or water. § 125. The alcohol in which brains are stored is main- tained at not less than eighty-two per cent. upon the al- coémeter scale of Tralles (§ 126). Weaker alcohol is employed for the immersion of fresh brains, for soaking out the dark coloring matter from brains that have been hardened in Miiller’s liquid, or for the preservation of other specimens requiring a less strength.* § 126. Alcodmeter (Alcoholometer).—This form of hy- drometer, for determining the percentage of alcohol in a given liquid, should be marked with Tralles’ scale. With the slender jar for containing the tested liquid, the cost is about $2.50, but its employment is to be recom- mended upon the ground of ultimate saving of alcohol. § 127. Dilute Nitric Acid.—Thisis useful for softening the cranium of infants or small animals so as to permit cutting with knife or scissors. A ten-per-cent. solution is sufficient. Ordinary commercial acid is about sixty per cent. ; the desired reduction is accomplished by add- ing five parts of water to one of the acid by weight, or seven of water by volume. The specific gravity of the mixture is about 1.057. In any mixture the per cent. of acid may be determined by the method recommended by Fresenius, second American edition, p. 688. § 128. Storage of Hemicerebrums.—The human hemi- cerebrum is a somewhat bulky mass, and may occupy a six-by-eight-inch Whitall & Tatum jar (Fig. 990). Sometimes both halves of a cerebrum may be accommo- dated, although the undivided cerebrum or entire brain commonly requires a nine-by-eight-inch jar. The most favorable method of storing several hemi- cerebrums is in jars nine inches in diameter and of any desired height. The specimens are set in tiers of three, their dorsal convexities against the sides of the jar. Suc- cessive tiers are so placed that a hemicerebrum rests upon the interval between two below. There will be a central vacancy which, if the jar is to be transported, may be filled with absorbent cotton; the alcohol (ninety-five per cent.) should be introduced last. § 129. Transportation of Fresh Brains. — Without affirming the impossibility of transporting a fresh brain safely in a bed of cotton or other soft material, I have found it much better toemploy a liquid of approximately its own specific gravity, about 1.04. The most easily prepared is brine, nearly saturated. Nor is it best to put. in cotton or other material. The brain should just float, without pressing upon the bottom of the pail or rising above the surface. The cover of the pail may be secured with strips of surgeon’s plaster. In cool weather a journey of two or three days may be safely accomplished. In warm weather, if the brain is well cooled inadvance and the smaller pail set in a larger and surrounded with rather large pieces of ice, a day’s. * The “ economics of alcohol ”’ is treated somewhat fully in W. & G..,, pp. 111-1380. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, journey may be accomplished safely. Such open pack- ages should be plainly marked “Specimens of Natural History. This side up with care.” (See also p. 206.) § 180. Other Liquids.—It must be remembered that while brine supports the brain and thus averts mechani- cal injury, and while it retards decomposition, it is not strictly a preservative of nervous tissue. Hence, espe- cially if the weather is warm or transportation is to occupy more than a few hours, it is well to place the brain at once in a liquid which will not only support but preserve it. Several such are enumerated in §§ 81-90. § 131. Transportation of Hardened Brains.—Already hardened brains may be transported either in a small pail of alcohol with cotton as a padding; or in a soldered box; or in a jar (the rubber of which must then be well covered with vaseline to be afterward removed) ;* or simply wrapped inalcoholic cotton covered with paper and oiled silk, or rubber sheeting, and packed in a box with soft material. Glass and metal packages are always enclosed in wood + or corrugated pasteboard. § 182. Removal of the Pia.—The early removal of the pia t has been already recommended, € 40. I have seen some otherwise valuable cerebrums materially injured by faulty methods, and a few suggestions are here offered. A. Begin with the central fissure, if it can be recog- nized, and at about the middle of its length. Apply the coarse forceps so that their approaching points move in the direction of the length of the fissure; pinch up a fold of pia; with the scissors snip at either side of the fold so as to raise it a little; then carry the forceps, held in the same way, more deeply into the fissure, not more than 1 cm. deep, and attempt to draw out the intrafissural fold of pia. If successful, continue to pull lengthwise of the fissure, cutting the pia at either side whenever necessary. B. Most of the other fissures may be dealt with in the same way; but some, notably the occipital and calcarine, are very deep, and arteries traverse them which must usually be cut more than once. C. The Sylvian fissure is not only deep, but spreads laterad over the insula, and there are several arteries. Rather than run the risk of tearing the adjoining gyres it is better to remove only so much pia as easily separates, leaving the rest and the arteries until one of the opercu- lums can be cut off and afterward replaced. D. While removing the pia or studying the lateral fissures of young or fetal brains, breaking is avoided and divarication of the gyres facilitated if the hemicerebrum is placed on its meson on a piece of thick Manila paper (such as is used for the portfolios), which is sufficiently firm to support the organ and yet yields so as to permit the exposure of the fissural depths. When the mesal surface is studied the specimen should rest in a thick bed of cotton. § 183. Prevention of Drying.—The strong alcohol in which brains are preserved (eighty per cent. and upward) evaporates rapidly while the brain is exposed, as in ex- amination or dissection. It may be dipped in the alcohol occasionally, or—which is preferable with delicate speci- mens—the alcohol may be allowed to drip gently upon it from a pledget of absorbent cotton. When a specimen only partly submerged in alcohol has to be left for a short time, drying may be prevented by covering it witha thin layer of cotton, one end of which dips into the liquid. § 134. Dissection of the Brain.—As commonly practised this contrasts strongly with the examination of the rest of fhe body. With the latter dissection is universal, and sections are seldom made or even studied;§ but with the former, sections, macroscopic or microscopic, are the * Vaseline will prevent the leakage of alcohol or other liquid ; but, like oils and grease, it disintegrates rubber; hence the rubber rings should be thoroughly cleansed from it after use. + For mailing alcoholic specimens contained in vials of not over four- ounce capacity, see circular of the Denison Manufacturing Company, New York City, as to “‘iiquid mailing boxes.’’ See also a paper by F. T. Gordon, Medical Record, \vii., 696. ¢It is understood that this includes the arachnoid, which on most parts of the cerebrum adheres closely to the pia; Fig. 796. § Notwithstanding the example and opportunity offered by works like Braune’s *‘ Atlas of Topographical Anatomy’’ and Dwight’s “Frozen Sections of a Child’ and ‘‘ Anatomy of the Head.”’ rule, and dissections, careful, prolonged, and thorough, are nearly unknown in medical schools. Like the pre- ponderance of osteology over neurology, the difference is due to the “nature of things”; but like many other nat- ural conditions it may need modification. The advantages of sections for surgical, pathological, and regional study are obvious; they are easily made, even with the fresh adult human brain, especially by means of the apparatus devised by Professor Dalton.* If the human brain were like that of the frog or opossum, with the several segments of approximately equal size, and nearly upon the same plane, the common method would be more appropriate for macroscopic study. But, in view of the extreme cranial flexure and the overlapping of certain segments by others, the objections to sections are as follows: 1. They present plane surfaces which do not naturally exist in the brain. 2. They are almost invariably oblique with respect to the axis. 3. They commonly include more than one encephalic segment, and are, therefore, so far as the beginner is con- cerned, apt to be more confusing than instructive. 4. They present the parts in contiguity rather than continuity.+ The foregoing objections apply to all sections. A macroscopic section, especially of a brain which has had the cavities alinjected, presents the advantage of exhibit- ing in perspective enough of the natural contours of parts to facilitate their recognition and comparison. Admitting, then, that sections have their uses, what is urged is, not that section-making be practised less, but dissection more. § 185. Preliminary Dissection of Alcoholic Brains.—I am yearly more convinced of its importance on four grounds: A. The brain is a complex organ and at the best per- plexing; the simpler features of form, location, and rela- tion to cavities are morphological, while color, like his- tological composition, has a physiological significance. B. The fresh brain is less easy to dissect neatly, and requires constant support against its own weight, whereas the alcoholic may be held in any position and carved like cheese. C. The beginner should advance cautiously, and there- fore slowly, and the medical student is especially liable to interruption. The fresh brain remains fresh but a very short time, while the alcoholic is in itself imperish- able. Leisure means not only more careful dissection, but also the taking of notesand the making of drawings; hence all the arguments which I have advanced (W. and G., pp. 55, 56) in favor of preliminary anatomical work upon a small animal, which may be kept in alcohol for an indefinite time at slight expense, apply to all alcoholic brains in general, and to those of moderate size in par- ticular. D. After repeated dissection of alcoholic preparations, the anatomist is better qualified to manipulate the fresh brain and to appreciate its beauty. The last word is used advisedly, for, however unattractive may be “subjects” and pathological “cases,” the most exacting artistic sense can hardly fail of satisfaction with the soft white and gray and pink of the newly extracted brain. Resting securely in its calva, for him who has been disciplined by prolonged experience with the “ pickled” organ, there are few more attractive, stimulating, or nourishing articles of intellectual pabulum than a fresh brain “upon the half shell.” § 136. Déssection.—Whether fresh or hardened, I be- * ** Topographical Anatomy of the Brain,’’ Philadelphia, 1885, vol. i., pp. 4-10; abstracts in New York Med. Record, February 15th, 1879; July 31st, 1880. , + Solly’s vigorous reprobation refers particularly to horizontal slic- ing: ‘It is unfortunate indeed that candidates for the medical dip- loma are still very generally required to describe the appearances presented by the brain dissected, or rather destroyed, by the old method of slicing—a method most unphilosophical in its conception, and totally inadequate to impart any real information in regard to the structure of the brain.” co 6) oo. Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. lieve the first step should be to slice off the dorsal parts of the cerebrum to near the level of the callosum and the next the exposure of the paraceles as described in con- nection with Fig. 735. The occipital lobes may then be cut off opposite the splenium and one or both medicornua followed to the tip of the temporal lobe. The next object should be to remove the overlapping parts of the cerebrum from the subjacent diencephal (and so much as may remain of the other segments) so as to obtain a view of the ventral aspect of the splenium and fornix. These may be transected a little caudad of the portas. There will then appear the velum, with the epiphysis. If the velum be lifted carefully there will be recognized the attachments along the dorso-mesal curvature of the thalami which are commonly ignored but insisted upon in Fig. 732. A transection through the portas will give a view of their boundaries, of the cephalic aspect of the medicom- missure, and of the caudal surface of the fornix and the precommissure; most of the other features are more easily examined upon the mesal aspect of the medisected brain. Somewhat full directions for dissection are given by Edinger. Complete directions are desirable, accompanied by figures indicating the appearances presented at each, Blunt-Pointed Scalpel. Syringotome. OX, Wi Hl | 3 J ei il i ‘a cox | it i ll 2 i Arthrotome. Tracer. nil FIG. 985.—Some of the Instruments Useful in the Removal or Dissection of the Brain. All of actual size. The two upper are eye-knives ; the syringotome is commonly called canaliculus knife ; (“foramen of Monro’) and the metapore (‘foramen of Magendie”’), prominent edge might do injury ; it has been my of air may be utilized by using the larger half of the metal pipe, handle continuous with the blade, curved forceps represented have t favorite instrument since 1866. Th more costly syringotome, but its chief use is in isolating nerves and vessels b soon tire the hand or hinder delicacy of manipulation ; the coarse ‘* Coxeter lighter than usual. The flexible blowpipe is most readily made by attaching to a piece of rubber tubing, of the metal blowpipe commonly sold with dissecting instruments. The length of the tube enables the venient distance from the eye ; since inflation is temporary injection, the advantages of witnessing the effects are obvious. and glass cannulas of any size may be employed. The arthrotome has the and one edge of the blade is rounded, excepting near the tip; it is practically a cartilage knife. The fine he points simply serrated ; but for the removal of the pia from the brain surfaces, Fine Curved Forceps. (From ** Anatomical Technology.’’) it is of great use for exploring orifices, the porta and for dealing with membranes and plexuses where a point or a e tracer may be employed sometimes in place of the y tearing the connective tissue. Most forceps are too stiff and ” forceps represented have the blades excavated so as to be 30 to 40 em. long, the smaller half object inflated to be held at a con- A larger volume and especially from the depths of fissures, a pair with interlocking teeth, like those of artery forceps, will be found very useful. 384 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, stage, such as I have framed for the brains of the cat (W. and G.) and sheep (“ Physiology Practicums ”). § 187. Instru- ( . th , ments.—The instru- ments employed in the removal or dis- section of the brain ($$ 50, 186) should, as a rule, be re- served for that pur- iy pose. If used in " ordinary dissection their points and edges should be at- tended to without delay. Some of the less familiar instru- ments are shown in Fig. 985. § 188. Probe- Pointed Curved Bis- toury.—This is practically a longer and stronger syr- ingotome (Fig. 985), the cutting edge being about 5 cm. (2 in.) long, ending in a probe point. The curve is less than that of the syringotome. It replaces the latter in the dissection of the entire human brain, and it is par- ticularly applicable to transecting the brain through the mesencephal, to tracing the medi- cornu, and to slit- ting the arachnoid in following the Sylvian or other deep fissures. § 139. Besides the instruments shown in Figs. 985 to 987, the following, more familiar, are indispensable : Scalpels of three sizes: large for sections; medium for ordinary dissection; small (“ Charriére”) for finer dissec- tion. Scissors, curved flatwise, three sizes. A hand lens, tripod magnifier or “linen tester.” A bone- chisel, or ordinary chisel of moderate width, or even a screw-driver sharpened slightly. A syringe, metal, or rubber bulb. Absorbent cotton; if com- mon cotton is used it must be first thoroughly wet in alcohol or water. Cannulas, rubber tubing, and Fig. 986.—Diagonal Side-Cutting Nippers. A little less than actual size. From ** Anatomical Technology.’”’ This is the smallest size of the English make (Stubs’), and for most purposes should have the handles lengthened by pieces brazed on. The German and Swiss in- struments (for sale by large hardware dealers) are less highly finished and costly, but answer nearly as well. Of these, seven sizes are made, ranging in length from 10-20 em. (4-8 inches), and in price from 60c. to $1.50. Surgical bone forceps and dental wedge-cutters have a spring between the handles and are more expensive. The nippers are most serviceable for removing the calva of infants and fetuses and of small animals. In use they must cut or squarely break the bone; the pulling and tearing to which one naturally re- sorts will inevitably tear the brain or its meninges. the Y-tubes or T-tubes for branching of injection . tubes may be had of dealers. The smaller end of a straight “medicine dropper” makes a fair cannula. aE Fic. 987.—Steel-Handled Spatula. x 0.5. of Whitall, Tatum & Co.) This (ora palette-knife, or round- ended shoe-knife, ground thin so as to be flexible) is indis- pensable for detaching the dura when the calva is to be removed. The methods of making and securing cannulas, and of making injections, are detailed in “ Ana- tomical Technology,” pp. 137-148. Cheap and efficient pinch- cocks may be had in the form of the wooden, spring clothes- pin, which may be variously attached to the wire cranes or used in- dependently upon the tubes. § 140. Saws.—There is no special advantage of the expensive surgical or anatomical saw over Vou. I.—25 Fic. 988.—Head-Rest for the Removal of the Brain. Stroud. A, Baseboard; B, upright board, hinged to A and secured by hooks. the ordinary carpenter’s instrument; it should be kept sharp and well-set, and used for no other purpose. For dividing the cranium any small saw will answer, but the edge should be rather wide so as to make a broad kerf. For medisection of the head, however, the saw should be very large, fine toothed, thin (7.e., make a narrow kerf), have a removable back, and be very sharp and free from rust. § 141. Saw-Box.—This (which might be called a macro- tome) is a coverless box made of boards about 2.5 cm. (1 in.) thick, and with the following inside dimensions: length, 30 cm. (12 in.); height, at middle, 25 cm. (10 in.) sloping to 15 cm. (6 in.) at the ends; width, ac- cording to the length of the neck attached to the head, 25-40 cm. All the parts must be accurately squared and put together with screws. The sides should go outside the bottom and ends, and the bottom have a cleat at each end. Each side is to be divided squarely at the middle of its length by a saw of the same thick- ness as that with which the head is to be cut; the bot- tom also is to be sawn to the depth of 1-2 mm. When finished the box should be thoroughly oiled, inside and out, with linseed or olive oil, to prevent warping when it is wet. § 142. Head-Rest for the Removal of the Brain.—The following description and figures (988, 989, and 982) are from the paper of B. B. Stroud (1900, 5) who devoted much time to the device. The apparatus was shown at the meeting of the Association of American Anatomists in Washington, May 2d, 1900. “This apparatus was devised for the purpose of hold- ing the head firmly with the base of the cranium hori- zontal. This enables the base of the skull to serve as a shallow tray in which the brain is supported during its removal. The subject lies upon the belly, being sup- ported by adjustable clamps fitting into the auditory meatuses, and the head naturally assumes a position in which the long axis of the cerebrum is nearly horizontal. Repeated trials in the neurological laboratory at Cornell University this spring have shown that with a maxi- mum of convenience to the operator there is a minimum of danger of rupturing the cranial nerves and certain delicate structures of the brain itself, which are fre- quently torn when the usual methods are employed. Fig. 988 shows a general view of the apparatus. Fig. 989 shows details of construction. In Fig. 982 it is rep- resented in use. “The device consists of a baseboard A to which is at- tached at right angles a second board B. Both are of seven-eighths-inch oak. Professor Wilder suggested that the upright board should be hinged to the base for con- Devised by B. B. (From Stroud’s paper, 1900, D; see Figs. 982 and 989.) 385 Brain. Brain, venience in storage and transportation. valuable improvement. “The upright B—Figs. 988 and 989, A—has a middle emargination and the sides are cut at an angle as shown in Fig. 989, A. Thechin-rest D is hollowed upon the top to fit the chin. It slides in a shallow groove 0.5 cm. (4 in.) deep, cut in B, and is adjustable by means of the thumbscrew. Thetwo lateral bars # are of iron. They project 3.5 cm, (1} in.) above the board B, and serve to support the two jaws F’and G. “The two clamps for grasping the head, Fig. 982, shown in detail in Fig. 989, B, consist of the jaw /, the guides This is a very C Fic. 989.—Portions of the Head-Rest. A, the upright board, with its side irons, E. B, One of the two clamps for grasping the head. C, improved form of the jaw-piece, F’. I, and the screw J, which pierces F in the form of a spike H, 2 cm. (? in.) long, to enter the auditory meatus. A flat head J, Fig. 989, B, is more convenient for turning the screw than the round milled head shown in Fig. 988. The jaw /'is bent flatwise to fit the curve of the skull and grasp it dorsad of (posterior to) the mastoid process. The other end is curved downward, to fit under the zygoma and thus hold the head more firmly. The guides J are made from one piece of steel bent in the form of a rectangle and made to fit very closely to the top of the side iron #. They and the curved form of /’ prevent a disagreeable rocking motion of the head. F is firmly riveted to Z by means of four double-headed rivets. The upright B is held in position by the two hooks K avOl IL * For the convenience of those who may desire to construct the head- rest the detailed specifications are here reproduced: A and B are made of %-in. oak. A is30x40cem. (12x18in.). B is 30x26 cm. (12x104% in.). It is cut as indicated in Fig. 989, A. The middle cut is 15x13em. (6x5in.). The front side contains a groove 4 in. deep and 39 in. wide to receive the chin support D. Dis of oak 5x9x17 em. (2x 34% x 634 in.). The top is hollowed out to fit the chin 4.5 em. One and seven-eighths in. from the top it is cut down so as to be only .5 in. thick. There is a slot in the middle to accommodate a set screw for fastening it at the different heights. H is an iron bar, 17x2x1 cm. (634 x 34 x 34 in.), and is bent at a point 3.5 em (14% in.) from the top so as to be perpendicular to the base A. F' is of 3; in. steel, 9x3 em. (314 x 114 in.) and formed as shown in Fig. 989, B and C; 1 is the front end shaped so as to fit under the zygoma; 2 is the rear end and grasps the temporo-occipital bone dorsad of the mastoid process. The clamps J are made of 3¢-in. steel 12 x 2.5 em. (434 x 1 in.) and bent as shown in Fig. 989, B. The screw J operates the jaw F. It is made of ye-in. iron 4 in. long. It has a shoulder which is received between and I. The spike H projects one inch beyond F to be inserted into the auditory meatus. A flat head is more convenient than the round one shown in Fig. 988. All sharp edges should be rounded and smoothed to avoid accidental injury to the operator’s hands. 386 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. § 143. Agate- Ware Pans.—The brain anatomist will find most convenient, and in the end most economical, one or’ two “nests” of iron pans, “enamelled,” so as not to rust, with plates of the same for covers. For the largest size- (11 x 4 in.) covers of glass or metal must be provided;. this size will accommo- date a half head. § 144. Butter jars, 10 < 10 cm., or 10 x 20 cm., with tin screw-cap, parchment lined, are sold by the Excelsior Package Co., 49 Warren Street, New York. They are very convenient for temporary storage or for transportation. § 145. Labelling Speci- mens.—Much of the real value of a specimen de- pends upon its identifi- cation as being a certain part of a certain brain, taken from an individ- ual of a certain age, sex, and nationality, and pre- served in a certain way. Even if the possessor has so few specimens that he feels sure of re- membering the entire his- tory of each, his death would abolish the source of information. I have observed surprising in- stances of carelessness in this regard, even upon the part of some who should set an example of scientific accuracy. Were the specimen never to be removed from the jar in which it alone is kept, the object could be accomplished by inserting the label in the jar or attaching it thereto; but this is rarely an: adequate precaution, neither is it often possible to state all the desirable data upon a label attached to the specimen itself. The most satisfactory plan tried is. the adoption of a serial number for each brain. § 146. Ali Specimens are Num- bered.—As soon as received every brain is assigned a number which permanently designates it and all parts into which it may at any time be divided; the same number per- tains to all notes, photographs, and drawings of it. § 147. Sometimes, as with entire: brains or half-brains, it is possible to attach with a cord a metal (sheet. block tin, stamped) number. But commonly the nymbers are written. with India ink* upon bits of parch- ment and attached by small (rib- bon) pins. + § 148. For purposes of dissection, photographing, or drawing it may sometimes be necessary to remove the label, but ordinarily it should be affixed to some other re- gion, so that there may be no possibility of misplacement.. Fig. 990.—Specimen Jar, with Glass: Top, Rubber Ring, and Clamp. (Made by Whitall, Tatum & Co., New- York.) Fourteen sizes are made, ranging from three to nine inches im diameter, and of various lengths.. The size here shown is 6 X 12, and will receive a half brain or the two- halves of a medisected cerebrum 3; for undivided brains and for medi- sected heads the size 9 X 8 suffices. These two sizes cost, respectively, $10 and $18 a dozen. ‘The prices. given in the catalogue are subject. to a discount of fifty per cent. Fie. 991. — Landen- berger’s Specimen Jars. These have a rubber ring and a glass top retained by a wire. The smaller size is 3 X 3in., capac- ity 6 oz. (180 ¢.c.); the larger, 3X4 (high), capacity 10 oz. (300 ¢.c.). 25N. Thirteenth Street, Philadelphia. * Good pencil marks last a long time in alcohol, but ordinary black ink is speedily washed out. : + In time ordinary pins corrode and may break the brain substance when withdrawn; pins of aluminum or silver should be available at a moderate cost. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, § 149. Distinctive Labels.—The ready recognition of cerebrums belonging to groups may be provided for as follows: ; A. The sexes are distinguished by using quadrangular labels for males and circular ones for females. B. Presumed normal white brains have white labels; Africans (of all shades), gray; murderers and other crim- inals, red; insane and idiots, blue. § 150. Immediate Records are Made.—No one’s memory is conceded to be infallible. All data concerning a brain not obtainable from the specimen itself are recorded without delay under the number assigned to it; eg., the sex, age, known, believed or estimated, race, known or supposed weight when fresh, donor, mode of initial pres- ervation, weight or bodily condition of the individual, and his character or mental state. § 151. Card Catalogue.—The basis of the records of each brain is a card bearing the number of the specimen at an upper corner. Upon the face of the card are written the data men- tioned in § 150; also, or continued upon the back, the numbers of neg- atives, and references to published figures or descriptions; suggestions of points to be elucidated are com- monly put on paper slips.* § 152. Drawing is insisted upon.t These drawings should be, primarily at least, in outline only; shading, like charity, “covereth a multitude of sins.” § 153. In beginning the study of a difficult region, the student is ad- vised to determine at once some prominent feature as a landmark, as a “base,” so to speak, “of intel- lectual supplies,” from which he may explore in any direction, and to which he may return when doubts arise. § 154. No observation involving either complex manipulation or novel results is published until it has been submitted to at least one other trained observer. § 155. It is freely admitted that rarely, if ever, is all possible information gained from a specimen at one ex- amination or by a single observer; hence specimens are preserved. ¢ § 156. Methods of Representing the Brain.—The follow- ing considerations and suggestions apply more or less directly to all natural history illustrations, but with especial force to the human brain, on account of its soft- ness when fresh, the difficulty of preserving it, the great size of the entire organ, the minuteness of certain por- tions, the large number of recognizable parts within a Fig. 992.—Tall, Round, Screw - Capped Jar, with Nickel- Plated Caps, Cork-Lined. Three sizes, viz.: four ounces, eight ounces, and sixteen ounces. (Whitall, Tatum & Co., New York.) Answers well for dry or non- volatile contents or for the temporary storage of alcoholic speci- mens. * My own use of slips of convenient size for notes and drawings and descriptions began in 1867 while I was assistant in comparative anato- my at the (Agassiz) Museum of Comparative Zoology at Cambridge, Mass. The slips were about three by five inches. When the first United States postal card was issued that size (13.5 < 7.6 em., 5.25 x 3in.) was adopted. But the subsequent introduction of other sizes has invalidated that standard, and the common and increasing em- ployment of the catalogue card of the Library Bureau (7.5 * 12.5 cm. or 3 X 5 in.) may render it desirable to adopt that size for notes as well. Brief accounts of the ‘‘slip system of notes” are given in Science, January 16th, 1885. and in Wilder and Gage. + Every student of any branch of natural history should compel him- self to learn to draw, however slight may be his inherited artistic ca- pacity. Not merely the laboratory students in Cornell University, but the members of the large general classes in physiology and zoology are required to make drawings of entire animals, and of the parts ex- posed in their dissections. + The time has not yet come, and indeed shows no signs of ap- proach, when I can look at even a familiar brain preparation without learning a new fact, gaining a better insight into what was already known, or receiving an impulse toward some special inquiry. , Db: The Use of Formalin in Neurology. Micros. Society, xvii., 319-830. , 1897 : The Mummification of Small Anatomical and Zoological Specimens. Proc. Ass’n Amer. Anat., December, 1897, pp. 59-61. Stroud, B. B., 1897: On Brain Preservation. Proc. Ass’n Amer. Anat., 1897, pp. 30-82. A 1900: A New Head-Rest for the Removal of the Human Brain. Proc. Ass’n Amer. Anat., May, 1900, pp. 10-i4, 5 figures. Wilder and Gage, 1892: Anatomical Technology as Applied to the Domestic Cat, third edition, from the second revised, O., pp. 600, 130 figures, and 4 lithographic plates. Preliminary Proc. Amer. ’ Wilder, B. G., 1896, g: The Desirability and the Feasibility of the Ac- quisition of Some Real and Accurate Knowledge of the Brain by Precollegiate Scholars. Amer. Soc. Naturalists, December, 1896. Science, vi., 902-908, December 17th, 1897, 3 figures. BRAIN: PACCHIONIAN BODIES.—These granula- tions, once falsely called glands, were perhaps first men- tioned by Willis (1676), then by Méry (1701), and almost simultaneously described by A. Pacchioni. They start as minute spheroidal, partially vesicular outgrowths (villi of Luschka) from the arachnoidal layer of the pia— where it bridges fissures as well as where it rests on the gyres,—retaining its epithelial covering. They must not * Even more objectionable is the omission of the original pagina- tion upon the reprints of papers. The printer does not always realize the conditions and the author often remembers when it is too late. 389 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. be confounded with granulations of the choroid or epen- dyma, with vegetations notably in the cavernous sinus (Hyrtl, 1862), nor with granular (aciniform) conditions of the meninges seen in inflammations. They are often clustered, become pedunculated, penetrate the opposed dura, and finally project into the overlying venous channels, and even excavate (in part repel) the bone. They are usually most abundant opposite the middle of the falcial sinus—more correctly opposite the largest parasinual spaces—but may occur on both sides, along nearly the whole length of this sinus, beside the trans- verse and tentorial sinuses, and even beneath the latter, also in the temporal fossa opposite the trunks of the medidural vessels and the frequently present temporal sinus. They occur not rarely 3 cm., and even farther, from the long sinus along the line of large incoming veins after the latter have left the pia, and also farther out at one point near the frontal border of the parietal bone, probably where a medidural artery bends to connect through the skull with temporal vessels. Hence, in gen- eral, they occur opposite intradural blood channels of some size, and especially those subject to continual varia- tions in calibre (pulsation, ebb and flow). Their preva- lent growth toward and into venous spaces has led to the assumption that the granulations themselves were venous structures, or opened into such (Key and Retzius, Koll- mann, and others; it is not true that Trolard claimed this). But it is now generally thought that the in- jection of the spaces through the granulations must have been effected by the rupture of granulation vesicles.* From the intimate connection of the older granulations with the spaces, they become darker colored; or, on tearing the two structures apart, flecked with blood. But the younger free corpuscles are pale, whitish. The parasinual spaces are said rather to diminish with age, while the granulations certainly increase. Up to the twentieth year they are rarely developed to any ex- tent. In congenital defect of the heart, they appear early and excessive (case of Lambl, 1860; one of the writer). However, at all ages continuous or intermittent compression of the brain space, of whatever origin, is the most frequent cause of their over-development. Under this head fall intracranial tumors of any kind or seat. Repeated congestion, as in chronic alcoholism, is also an accepted factor, doubtless acting mechanically. Various systemic troubles, as nephritis and diabetes, favor the enlargement of these bodies, possibly by un- usual variations in the encranial pressure. In view of all the facts—viz., that while these cor- puscles regularly occur opposite intradural (extra-arach- noidal) blood channels not necessarily venous, their growth is especially favored on the one hand by venous stasis, on the other by pressure from the side of the cranial space—it is evident that they result from the oft- repeated local oscillation of the arachnoid. As the cere- bro-spinal fluid is subarachnoidal, it, especially when under pressure, forces that membrane at its weakest points into any depression, as that beside a dilated vessel —the granulations always grow away from the cranial cavity, never toward tt. When, then, the favoring condi- tion—be that even negative instead of positive—relaxes, the granulations, to the extent that they have formed, press against and penetrate superimposed structures, the continuous alternation of the conditions as continu- ally favoring the process. This, as we believe, clear and simple explanation suffices for all the main features of these little growths. PaTHoLoGy, Cuinical History, ETc.—(a@) Like the wrinkling of the skin, the turning gray and falling out of the hair, and many other processes, the granulations themselves should be considered pathological only when they become excessive or develop prematurely. (0) Calcification or ossification of these bodies is not un- * This is a matter of interest in connection with the theory of brain pressure (Hirndruck). Bergmann lays much stress on the continu- ous (or intermittent) discharge of cerebro-spinal fluid through the granulations into the venous spaces; while Adamkiewicz ignores or argues against the existence of such discharge. 390 usual, They may contain deposits of so-called brain sand and even fat globules. (c) Where they penetrate into blood spaces and even a sinus, they so far interfere with the return current, and also favor thrombosis (only one case of the latter, Férster’s, has been attributed to this cause). (d@) Fovere glandulares, sharp depressions or ex- cavations in the inside of the skull (preceding e and /), quite analogous to that seen in aneurism of a dural artery, are sometimes found. From their more or less intimate relations with the sinus walls, Allen advises avoidance of the middle line in all operations upon the skull cap. However, the diploé itself is never opened by these growths as a new layer of bone always forms around the fovex. (e) Small flat elevations of the ex- ternal plate of the skull, opposite the fovez, and hence near the superior median line, are mentioned by many. (f) Very rarely complete perforation of the cranium oc- curs. 1. Case of Weber-Ribes (1819; v. Pozzi); hole small, and covered by ligamentous membrane. 2. Luschka (p. 116); perforation of squamous portion of temporal bone. 3. Lecat (v. Heincke in Pitha-Billroth); pneumatocele capitis; skull at some points perforated by granulations of the dura. 4. Demme (1862; v. Mastin, “Venous Blood Tumors of the Cranium.” Reprint, 1886). “On the left of the sagittal suture (posteriorly) was a sharp- edged opening the size of a cherry stone, through which protruded a Pacchionian granulation.” 5. The writer’s observation. Man of forty; had suffered over three years from a tumor of the brain; autopsy, August, 1887. At the favorite spot near the frontal border of the parietal, somewhat removed from the sagittal suture, there was a clean-cut, complete perforation of the skull by Pacchion- ian granulations. This was circular, fully 0.5 cm. across, surrounded even in the diploic portion by smooth con- tinuous bone, and covered by periosteal membrane. At the border there was a very trifling over-projection of the outer bone plate. It is recognized that such perforations—even when in- complete—may, from local injury, lead to the formation of epicranial blood cysts, inasmuch as the causative granulations usually traverse some blood channel. (g) In a few cases growths of this class have pressed on passing nerves, causing local neuralgic or paretic symptoms. Though it has been claimed that at times these growths induce headache, it is probable that they are then but co-effects of some other cause. () In ani- mals generally these corpuscles are not present (brains of sheep, calf, rabbit, dog, and cat examined). Luschka found them only in the horse. William Browning. BIBLIOGRAPHY (MODERN). Luschka: Virchow’s Archiv, xviii. L. Meyer: Ibid., xix., 1860. H. C. Bastian: Quarterly Journal of Microscopical Science, 1866. Key and Retzius: Studien, ete., 1875, I. Halfte, Stockholm. Labbé: Archives de physiologie, 1879. H. Lahr: Dissertation, Berlin, 1880. Kollmann : Correspondenz-Blatt fiir Schweitzer Aerzte, 1880, No. 18. Browning: American Journal of the Medical Sciences, October, 1882. BRAIN: SIMPLE MENINGITIS.—(Pachymeningitis, mayvc, thick; leptomeningitis, Aettéc, thin; simple, as distinguished from cerebro-spinal and tuberculous menin- gitis; meningitis of the convexity as distinguished from basilar meningitis.) Meningitis, in general, was first recognized as an affection separate from disease of the brain by Morgagni, 1760. Epidemic cerebro-spinal meningitis first attracted the attention of Vieusseux, of Geneva, 1805, and of Strong, North, Fish, Hale, Miner, and Williams, of our own country, 1806-1814, and was at that early period easily differentiated from affec- tions limited to the membranes of the brain. Parent- Duchatelet and Martinet, 1821, first distinguished inflam- mation of the dura and pia mater, and Guérin and Guer- sant, 1827-1839, first distinctly recognized and set apart the tuberculous, granular, or basilar form of the disease. The first clear descriptions of the exclusively “simple” meningitis, from a pathological standpoint, are to be found in the works of Cruveilhier, 1880, and from a REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, clinical standpoint, in those of Andral, 1834, and of Rilliet and Barthez, 1848. The recognition of the fact that simple meningitis is always a secondary affection is the result of the more accurate post-mortem observations ‘of the last two decades, in the light of the recent in- ‘vestigations concerning infections, and the contributions from rhinology and otology. That the various forms of meningitis are caused by specific micro-organisms was pointed out by the work- ers in bacteriology, especially by Koch, 1882, who demon- strated the tubercle bacillus in tuberculous meningitis; by Leyden, 1883, who found a diplococcus in the cerebro- spinal fluid and the pia, which Fraenkel and later Hauser showed to be identical with the pneumococcus; by Weichselbaum, 1887, who showed the presence of the diplococcus intracellularis meningitidis in epidemic cer- ebrospinal meningitis; and by Foa and by Bordoni-Uffre- duzzi, who described a third and a fourth variety of the meningococcus. Weichselbaum in Germany and Adenot in France, 1884, showed that meningitis occurring during or after an attack of pneumonia depended as a rule upon the same micro-organism that caused the pneumonia. Later observers have found meningitis frequently due to the pneumococcus in the absence of pneumonia. Thus the pneumococcus was found by Grasset in cases of menin- gitis occurring with inflammatory rheumatism; by Gabbi and Puritz in cases of meningitis associated with periar- thritis and endocarditis; and by Ellehorst in a case of meningitis apparently due to fracture of the base of the skull. The diplococcus intracellularis meningitidis is believed by some observers to be a variety of the pneumococcus, while others hold that it is quite a different crganism. The latter view is held by Jaeger, who believes that the dipiococcus intracellularis meningitidis is the cause of epidemic cases, while sporadic cases may be due to the pneumococcus. Jaeger proposes the name tetracoc- cus intracellularis for the micro-organism described by Weichselbaum as the diplococcus intracellularis, since this organism frequently appears in the form of tetrads. In 25 cases of suppurative meningitis reported by Netter the pneumococcus was found in 18, the strepto- coccus pyogenes in 4, the diplococcus intracellularis in ‘2, and the typhoid bacillus in 1 case. Next to the tubercle bacillus, the typhoid bacillus is most prone to cause purulent meningitis. Cases have been reported by Roux, Adenot, Kamen, Honl, Hintze, Fernet, Monsi and Carbone, Stiihlen, Tietine, and other observers. Next in the order of frequency, after the typhoid bacillus, is the bacillus coli communis, which has been found by Howard, Biggs, Sestre, Scherer, and others. A role in etiology has been ascribed to the bacillus pyocyaneus by Kossel, Pesina, and Honl. Among the pleomorphic bacteria that have been de- scribed in the exudates of meningitis are the cladothrix asteroides of Eppinger, and the actinomyces described by Moosbrugger, by Honl, and by Lenzine. Pachymeningitis, inflammation of the dura mater, pre- sents itself in two forms, external and internal, purulent and hemorrhagic, representing entirely different disease processes. form, is really the result of a degeneration rather than of an inflammation; but in theabsence of definite knowl- edge regarding the genesis of this disease, the two forms may be best studied together. PACHYMENINGITIS ExTERNA.—Accidents or injuries which directly expose the dura, or effect its separation ’ from the bones of the skull, with consequent extravasa- tion of blood, whereby is implied, at least, a “hidden crevice” or some communication of the dura with the air, lead at once to inflammation of the outer lamella which may extend so as to involve all the rest of the membranes of the brain. Carious processes of the ear constitute an even more frequent cause of this condition. A mere microscopic breach in the thin wall of bone that Pachymeningitis externa, the hemorrhagic — forms the upper covering of the tympanic cavity will bring pus from the tympanum to the dura. So, also, caries of the ethmoid bone (ozzna) or other bones of the cranium (syphilis, carbuncle) may excite this form of meningitis; and even without caries, purulent inflam- mation of the mucose in the ethmoid and frontal sinuses may extend to the dura through the natural openings of communicating vessels. This complication has been noticed more especially in erysipelas after “mixed infec- tion,” whose nature it is to spread. As purulent pachy- meningitis rarely remains confined to the dura, but ex- tends, as a rule, to involve the pia mater, the symptoms, pathology, and treatment of this condition will be further discussed with leptomeningitis. PACHYMENINGITIS INTERNA (Consult Plate XV., Fig. 1).—The disease of the dura which merits most con- sideration, from its frequency, limitation, and recogniz- ability in life, is that affection of the inner layer which is characterized by the extravasation of blood and subse- quent development of an adventitious membrane, com- monly known as hematoma dure matris, and technically described as pachymeningitis interna hemorrhagica. With these characteristics it is plain that internal pachy- meningitis does not supply the requisite conditions, nor rise to the nosological dignity of an inflammation in the modern sense of the term. It develops oftenest independ- ently of all infection, and should properly be discussed as a subvariety of cerebral hemorrhage. The pathology of this affection remains as yet obscure. The early anatomists and clinicians were fain content with descriptions of the condition without venturing to express opinions concerning the nature of the disease. It was commonly held and taught that the disease con- sisted in the extravasation of blood, and the only ques- tion discussed regarded its situation. Thus Abercrombie and Andral, 1807, maintained that the blood was effused between the dura and the parietal layer of the arachnoid so called; while Houssard, 1817, located the extravasa- tion in what was then, and for the sake of convenience is still, known as the cavity of the arachnoid. The hemorrhagic nature of the affection was nearly lost sight of when Bayle, 1848, considered the hematoma as an in- flammatory product of the dura, but it was again restored by Durand-Fardel, 1854, who believed in the develop- ment and organization of a flat blood clot. Heschl, 1855, regarded the membrane as a highly vascular connective tissue, a view which Virchow, 1856, with his predilec- tions for cellular pathology, elaborated into a hemor- rhagic inflammation of the dura as the first process, and a subsequent infiltration of blood as the second. The authority of these pioneers carried their views with al- most undisputed conviction up to our own times, when the studies concerning the nature and processes of in- flammation and infection naturally diverted attention to the condition of the blood and blood-vessels as prime factors in the production of the disease. That hemorrhagic pachymeningitis is not the expres- sion of an ordinary inflammation is shown by the fact that no amount of irritation of the dura will produce it. In- jections of ordinary irritants into and beneath the mem- branes of the brain of lower animals may be followed by purulent, but never by hemorrhagic, pachymeningitis. On the other hand, the injection of blood with all its constituents sufficed, in the experiments of Sperling, to produce the typical signs and lesions of the disease. The role of the fibrin in these cases is evidenced by the fact that a membrane was not developed after injections of defibrinated blood. Internal pachymeningitis consists, then, in the extrav- asation of blood, the formation of a blood clot which, when the effusion is not too great or rapid, is flattened by pressure, to become subsequently organized into a membrane. In the first stage of the disease process, the thin layer of coagulated blood soon begins to show, in the separation of its fibrin, a meshwork which contains multitudinous blood corpuscles. At this time there is no apparent connection with the dura, whose epithelium remains intact. In the consolidation which continues, 391 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. the clot assumes the appearance and density of a mem- brane, which now in reality develops, from the trans- formation of white blood corpuscles into spindle-shaped connective-tissue cells, whence the synonym, P. fibrinosa. The red corpuscles now gradually lose their coloring matter, which collects in spots on the surface, and in the texture of the membrane (P. pigmentosa) lose their regular contours, and finally become transformed into masses of protoplasm. Young vessels now connect the dura with the membrane, which becomes gradually more dense, thick, and adherent. In the mean time new layers of blood may be effused into the membrane already in process of formation, which consists thus of superim- posed lamellzee—Virchow has seen as many as twenty,— for a time separable from one another. The effusion takes place chiefly upon the convexity of the brain, limited, in fifty-four of sixty-five cases collected by Kremiansky, quite precisely to the region covered by the parietal bones. It is rather more frequently bilateral than unilateral, being confined to one hemisphere in but forty-four per cent. of cases. The source of the hemorrhage still remains a matter of dispute and doubt. Kremiansky thought it came from the middle meningeal artery, an origin which comports well with the situation of the clot; but Huguenin de- clares that he has never seen this vessel affected in any of his observations. This author is inclined to find the lesion in the veins which run from the cortex to the longitudinal sinus along the falx cerebri; and Pacchion- ian vessels have likewise been accused, but all alike without as yet satisfactory anatomical proof. The chief danger of these effusions is pressure upon the brain, which shows itself in proportion to the amount of the extravasation. Huguenin has seen a hemisphere flattened by a large unilateral hematoma, which may be as large as a hen’s egg—Hichhorst mentions effusions of 500 gm.,—and in some cases a lateral ventricle has been reduced by pressure to half its size. The great evil of pressure is obviated in many cases by the latitude allowed by atrophy of the brain substance, a condition rather, as a rule, coincident with hematoma of the dura. In fact, the greatest contingent of cases is found in connection with paralytic dementia, and cases independent of some degree of atrophy are comparatively rare. When, from any cause, a real inflammation is en- grafted upon this hemorrhagic degeneration, serum or pus may be found in connection with the blood which forms the hematoma. As curiosities in this direction, Virchow describes a hydrocephalus externus pachymen- ingiticus, and Weber saw, in a lamellated hematoma, blood in one cavity and yellow-green pus in another. Various changes in the skull, membranes and brain have been observed in connection with pachymeningitis, but none so frequently as to belong to it of necessity. Thus the bones have been found thickened or thinned, with an agglutinated dura at times, the pia anemic, hyperemic and swollen, or cloudy and opaque, separable from or adherent to the dura, etc. The frequency with which general atheroma of the cerebral vessels is seen, with thromboses, softenings, apoplexies, scleroses, etc., of the brain, bespeaks the intimate relation of these proc- esses to the development of the disease, in connection more especially with general paralysis, alcoholism, insan- ity, senile atrophy, etc. Pachymeningitis is a much more frequent affection than is commonly believed. Savage records its presence in three per cent. of the autopsies made at the asylum at Bethlehem, and when it is remembered that there are more cases of dementia and insanity, not to mention al- coholism, out of than in asylums, it is seen that this per- centage is far too low. It is safe to say that most of the cases remain undiagnosticated during life; and death, when it occurs, though perhaps caused by this affection, is ascribed to the disease in the course of which this ac- cident develops. All authors agree in noting three- fourths of all the cases in the male sex, a proportion which corresponds to the relation of the sexes to the affections which produce the disease. For the same 392 reason hemorrhagic pachymeningitis is a disease of ad- vanced life. Exceptional cases at early periods of life— six months to eight years—have been recorded by Weber, Moses, Steffen, and others, mostly in connection with the venous stases from the strain of asthma, pertussis, etc., or the impoverished nutrition of blood-vessels from scurvy, leukemia, and more especially pernicious ane- mia; and cases have been more abundantly reported dur- ing adolescence and maturity in connection with tuber- culosis, empyema, valvular lesions of the heart, the various forms of Bright’s disease, the various infections (variola, scarlatina, acute articular rheumatism, and typhoid fever), and more especially local injuries of the dura (seventeen of seventy-four cases described by Schneider); but aside from these accidents, pachymenin- gitis remains a disease of age. The largest number of cases, twenty-two per cent., in the collection of Hugue- nin, occurred between the ages of seventy and eighty. Symptomatology.—Internal pachymeningitis exists at times without a symptom to mark its presence. Moses reports such a case in a child, aged seven months, who died of catarrhal pneumonia. At the autopsy there was found a pachymeningitic cyst which covered the ante- rior half of the right hemisphere, though no sign of brain disease had ever been manifest in life. Slight extravasa- tions often show no sign because of absence of pressure, or, if slowly effused, because of tolerance, which the brain acquires often in astonishing degree. In other cases the accident is overshadowed by symptoms per- taining to the original disease. These are, however, all exceptional cases. As a rule, the disease may be diag- nosticated during life by signs which are not so valuable in themselves as in their etiological relations. In the majority of cases the disease announces itself suddenly and violently. The patient is stricken with apoplexy. The hemorrhage may be so great as to cause death by compression of the brain within forty-eight hours. The nature of the disease, or more strictly, the localization of the hemorrhage, is, as a rule, in such cases impossible to determine. The first attack is not, however, usually fatal. In exceptional cases the patient may recover fully, but as a rule a train of symptoms ensues which more or less distinctly characterize the dis- ease. These symptoms vary greatly in individual cases, vary according to the locality and extent of the effusion, as well as according to the nature of the original disease; but they do not differ in essential characters from the symptoms of meningitis from any cause. Headache, stupor, which may at any time deepen to coma, mono- plegias, hemiplegias, or, in the irritant stage, unilateral twitchings and convulsions, limited at times to one ex- tremity, or confined to the area of distribution of the facial nerve; aphasia, when the region of the language centre is compressed—these symptoms, together with an irregular or retarded pulse, vomiting, and more especially contracted or dilated pupils irresponsive to light, with little or no disturbance of general sensation, make up a group which as a rule distinguishes the disease. But, as already intimated, it is not so much the symp- tomatology of the affection as its etiological relations which strictly define the disease. The general signs of meningitis refer especially to hematoma only when they occur in the course of general paralysis, chronic psy- choses, alcoholism, chronic Bright’s disease, pernicious anemia, traumata, the affections mentioned in the dis- cussion of the etiology of the disease. Another distinguishing, but by no means so distinc- tive, feature to indicate the nature of the affection, is the recurrence of the symptoms. Total or partial recovery from all the general manifestations of meningitis is fol- lowed in pachymeningitis, as a rule, by repeated attacks, and though the special symptoms may show great variety in relapses or recurrent attacks, the general character of the new signs is definitely sustained. The Diagnosis of pachymeningitis is based upon these two cardinal points: the existence of an underlying con- dition or causative disease, and the more or less rapid recurrence of the attacks. Cases are further character- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, ized by suddenness of onset and rapidity of recovery. Dr. Whittaker had at one time under observation an in- dividual affected with chronic alcoholism who was sud- denly stricken with apoplexy on the streets. The pa- tient was carried comatose to the hospital. The coma subsided in the course of a few hours, to leave a com-- plete right-sided hemiplegia, which entirely disappeared in three days, leaving the individual in better physical and mental condition than for ten years. Many of the cases of so-called “serous” apoplexy, characterized by sudden onset, and more especially by speedy recovery, are really cases of pachymeningitis. The predominance of symptoms indicating cortical lesion is another feature of diagnostic importance. Thus localized convulsions and contractions, monoplegias, contracted pupils, following an apoplectic attack in an individual predisposed to the disease by the factors al- ready emphasized, point almost certainly to pachymen- ingitis. Considerable diagnostic importance has been attached to rigidity of an extremity, which often develops as an expression of irritation of the motor centre of the ex- tremity, to become later manifest by convulsion or pa- ralysis. Collins considers it rather characteristic that the cranial nerves always remain free. A point of differentiation from other forms of intra- cranial hemorrhages is that the symptoms come on grad- ually and the stage of irritation is prolonged. The age and sex of the patient must not be overlooked. Basilar meningitis is differentiated by the youth of the patient, the family history, the presence of tuberculosis elsewhere, by its long prodromes, its insidious approach, its general and special hyperesthesia, opisthotonos, boat- shaped abdomen, etc. Cerebro-spinal meningitis prefers winter, soldiers, and children, occurs at times in endemic proportions, shows opisthotonos, herpes, and sometimes petechie, extreme hyperesthesia, spinal lesions, and does not recur. The Prognosis is always grave. Recovery without recurrence is possible, but not probable. The patient succumbs, as a rule, in a subsequent attack, if he does not fall a victim in the mean time to the original disease. The immediate prognosis is best established, as after any cerebral hemorrhage, by frequent observations of the temperature, whereby the degree of the rise after the initial depression incident to the shock would receive proper interpretation. A sudden or gradual elevation to a high grade (105° F.) at any time thereafter, independent of the original disease, is a sign of most ominous sig- nificance. T herapy.—The treatment of pachymeningitis does not differ materially from that of any form of meningitis or cerebral hemorrhage. The application of an ice bag to the head, the local abstraction of blood by leeches or cups behind the ears or over the temples, “derivation ” by purgatives (calomel, senna, croton oil), constitute the routine plan, which is sanctioned more by time and use than by benefit based upon demonstrable proof. Tran- quillity of surroundings, with all the measures which make up a more or less perfect hygiene, is the most effective agent in prophylaxis in the chronic psychoses; while abstention from alcohol addresses the “ causa indi-. cationis ” in cases dependent upon its abuse. Bright’s disease, heart disease, pernicious anemia, etc., in short, the underlying condition, calls for appropriate treatment, and paralyses, convulsive manifestations, persistent head- aches, whatever symptoms may be left, are to be met with symptomatic treatment. PACHYMENINGITIS CERVICALIS HYPERTROPHICA is a peculiar subvariety of meningitis, produced by great thickening of the meninges in the cervical cord, ‘and marked by severe pains in the back of the neck and both arms, with atrophy of the muscles of the neck and flexors of the hands, and final spastic paraparesis. LEPTOMENINGITIS.—It is possible, as already stated, that a real inflammation may limit itself to the dura mater alone, but such a distinct circumscription is very rare. Inflammation of the dura extends, as a rule, so as to involve the pia mater. The same qualification applies to the pia mater, though a strict limitation to the pia mater is more frequently observed. The subsequent re- marks apply more especially to inflammation of the pia mater, with which the dura is, or may be, secondarily affected in greater or less degree, It is taken for granted that cerebro-spinal meningitis and tuberculous menin- gitis, diseases due to special causes, are not included under the title leptomeningitis, which embraces all other kinds of simple meningitis of known or unknown cause. Leptomeningitis is always a secondary affection. The cases considered idiopathic become, under closer obser- vation, so much fewer every year that it is more safe to appeal to unknown primary affections than to. sub- scribe to the possibility of a spontaneous or idiopathic meningitis of any kind. A thorough conviction in this regard will alone lead to the searching investigation nec- essary in many cases to discover the original disease. Affections of the nose, accessory sinuses, and ear con- stitute by far the most fruitful causes of leptomeningitis. Chronic suppurative inflammations of the tympanic cavity, which constitute over twenty per cent. of all dis- eases of the ear, frequently lead to meningitis through caries of the osseous roof of the tympanum. The roof of the tympanum is composed of an excessively thin plate of bone, which is indeed at times congenitally de- fective, so that the way lies open to invasion of the cranial contents. A more or less openavenue is also offered in the course of, or along the sheaths of, the facial and auditory nerves, and the vessels which penetrate the petrosal fissure. Communication by caries may be also directly estab- lished between the cavity of the cranium and the mastoid cells; while indirect involvement of the meninges may follow phlebitis and thrombosis of the cavernous, trans- verse, and superior petrosal sinuses, as revealed by dila- tation of the veins and local cedema in the region of the mastoid process. Tuberculosis plays a prominent roéle as a special cause in the production of all these processes, while syphilis furnishes a small contingent of cases through caries of the upper meatus of the nose. Every meningitis whose cause is not obvious should excite suspicion of disease of the nose, accessory sinuses, or of the ear. So, also, diseases of the nose, especially those involving the accessory sinuses; and every case of otorrhea, which may sometimes reveal itself to the sense of smell in an offensive odor, before or in the absence of visible discharge, should excite the fear of possible men- ingitis. Trauma or injury to the cranial bones constitutes a not infrequent cause of simple meningitis. When com- pound fracture has occurred, or direct penetration has been effected, the sequence is sufficiently simple. In other cases the meninges, though not directly exposed, become affected through phlebitis, thrombosis, or sup- purations occurring in the patulous veins of the diploé, whereby is implied, as previously intimated, some hidden crevice or pre-existent communication with the air. A far more infrequent involvement of the meninges occurs at times when an abscess in the interior of the brain reaches its periphery, or bursts into a lateral ventricle to come in contact with inflections of the pia mater at the base of the brain. So-called brain “softenings,” which consist simply of brain and tissue débris, and simple hyperemias, the so-called “congestions” of the brain, including sunstroke, could not, with our present knowl- edge of the nature of infections, produce a leptomenin- itis. ; Next in frequency to the direct invasion of the me- ninges from disease of the nose, accessory sinuses, and ear are the metastatic processes from distant ,depdts of in- fection. Any one of the acute infectious diseases may be thus attended or followed by meningitis, which is justly regarded as the most serious complication which can occur—which, indeed, imparts a sudden gravity to an otherwise mild case of disease. Of all the acute in- fections, pneumonia is the disease in which this complica- 393 Brain. Brain. tion most frequently occurs. The intimate relations of tuberculosis of the lung and brain in the frequent se- quence of basilar meningitis upon tuberculosis pulmo- num, prepare us in a measure for the frequent superven- tion of meningitis in the course of croupous pneumonia. The same connection or relation has been ob- served also in cerebro-spinal meningitis, and bacteriologists have pointed out the striking resemblance of the micro-organisms found in these two affections. Pyzemia and septicemia may be said to vie with pneumonia in the pro- duction of metastatic meningitis, while endo- carditis, empyema, acute articular rheumatism, the exanthematous diseases—more especially variola and scarlet fever (aside from ear dis- ease), and very rarely typhoid fever—diseases mentioned in the order of fre- quency, furnish WATTS x exceptional cases. © : ee Hinsdale reports 7 a fatal case of purulent menin- gitis in a new- born child, due to a bacillus belong- ing to the colon group, which had apparently gained entrance to the body through the um- bilicus. As curiosities equally illustrative, however, of the nature of the process may be mentioned the cases of meningitis which have followed such trivial infec- tions as vaccinia and mumps. In a few reported cases, a paradoxical pupil reaction has been noted, the pupils being contracted to the size of a pinhead in the dark, and widely dilated in the light. The condition is rare and no satisfactory explanation of it has been given. The morbid anatomy and symptomatology of leptomen- ingitis do not differ—aside from the fact that the convex- ity is more often involved than the base, when the inflam- mation is due to metastatic and traumatic causes—from the morbid anatomy and symptomatology of cerebro- spinal meningitis (to be described farther on, in this vol- ume). The Diagnosis of meningitis in connection with disease of the nose, of the accessory sinuses, or of the ear, or with a trauma of the bones of the cranium, is very easy, as a rule, but the diagnosis of metastatic meningitis is oftentimes exceedingly difficult. High fever and blood- poisoning may be productive of symptoms which so closely simulate the signs of meningitis as to render an ab- solute diagnosis impossible, at least for atime. The per- sistence of these signs after subsidence of hyperpyrexia sometimes declares the disease. Tuberculosis, pymia, scarlatina, variola, erysipelas, and typhoid fever are the affections which oftenest create doubts as to the diag- nosis. But if close scrutiny be made of the etiological factors, and close at- tention be paid to the course of the disease, the diagnosis, as a general rule, soon be- comes clear. In dis- tinction from tuber- culosis and typhoid fever, it may be said that meningitis develops quickly, almost suddenly, with violent pain in the head, active delirium, and often with stiffness of the muscles of the neck, or retraction of the head. The Kernig Sign.—In meningitis, according to Kernig, of St. Petersburg, if the hip be flexed so that the thigh is at a right angle to the body, the knee may not, with- out undue force, be extended in some cases beyond 90° (Fig. 993, A), never to the point of full extension (Fig. 993, B), and not farther than about 185° or 140° in any case (Fig. 994, (). With the hip extended, the knee may 394 cast Ph aN Ye 1 Anma= name nn neces ganeretnn, 4, FIG. 993.—The Kernig Sign. Fig. 994.—The Kernig Sign REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. be readily straightened (Fig. 994, D). Thus, the ability readily to extend the knee, when the hip is flexed at a right angle (Fig. 993, B), would speak strongly against the presence of meningitis. Netter believes that the sign described by Kernig de- pends upon inflammation of the meninges and conse- quent irritability of the nerves, which is increased by the stretching of the lumbar and sacral roots when the indi- vidual is in the sitting posture, so that the attempt to extend the knee is sufficient to provoke reflex contracture of the flexures of the leg. Such reflex contracture is not produced by extension of the knee when the thighs are extended upon the pelvis. The sign is not pathog- nomonic, as was at first claimed, although it is of great value in diagnosis. Netter has observed it in forty - five out of fifty cases of men- ingitis. Cipollina was unable to find it in some severe cases of menin- gitis, and did find it in other affec- tions without the symptoms or lesions of meningitis. Packard has reported three cases of meningitis in in- fants, with the diagnosis confirmed by autopsy, in which the Kernig sign had been persistently absent. The ab- sence of the sign was ascribed by Packard to a diminu- tion of normal muscular hypertonia in infants. In an- other case the sign was present but no anatomical cause for death was found. Lumbar Puncture (Quincke).—Puncture of the ver- tebral canal, which was originally used as a therapeutic measure, has proven of great value in diagnosis. At first the method was used in the study of diseases of the vertebral canal; but with the knowledge of the com- munication between the subarachnoid spaces of the brain and those of the spinal cord, the method has come into much more general use in the diagnosis of diseases of the interior of the skull. Method.—The trunk should be well flexed, preferably with the patient lying upon the right side and the legs drawn up, or with the patient sitting up and bending the body well forward. The punc- ture is then made, under aseptic precautions, with a clean needle. An aspirating needle with an in- ternal measurement of 1 mm. should be used in adults; in chil- dren, the ordinary hypodermic needle is sufficiently large. With the object of reach- ing the subarachnoid space at the begin- ning of the cauda equina, the needle is introduced between the second and third or third and fourth lumbar vertebra. The puncture is made in the median line in children; in adults it is better to make the puncture close to the spinous process a little to one side of the middle line, in order to avoid the strong supraspinous ligament. The needle is introduced inward and slightly upward, to a maximum depth of from 2 cm. for children to 6 cm. for adults. When the needle enters the subarachnoid space, a varying amount of cerebro-spinal fluid will usu- ally flow out, either in drops or ina stream. Occasion- ally the fluid will not escape or the flow will suddenly cease, probably through the occlusion of the needle by a nA tore REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, flake of fibrin or in consequence of an obstructing fila- ment of the caudaequina. To avoid injury to the spinal cord, it is better to detach the aspirator from the needle, and thus withdraw the fluid without force. Any fluid that is withdrawn should be examined macroscopically, microscopically, and bacteriologically. Thus may be determined, first, whether the fluid be clear, turbid, purulent, or bloody; and second, the micro-organisms that may be present either as the primary cause of the meningitis or as a secondary infection. Osler confirmed the diagnosis in this way in thirteen out of seventeen cases. (See also p. 248 of the present volume.) Tuberculosis and typhoid fever show typical tem- perature curves, with lung symptoms in tuberculosis, and abdominal symptoms in typhoid fever. In scarla- tina, variola, and erysipelas it is rather a question of detecting a complication, as each disease shows charac- teristic eruptions upon the surface. Here, too, the per- sistence of cerebral signs after subsidence of the high temperature is of value. Septicand pyzmic diseases fol- low wounds, are attended with chills, and show joint affec- tions and internal metastases. Ulcerative endocarditis, a septic process, has the same history. Uremia is recog- nized by the dropsy, the condition of the urine, and, so far as the nervous symptoms are concerned, by the pre- dominance of convulsions. Cerebro-spinal meningitis is differentiated by the more prominent disturbances of sensation, by herpes, and by the occurrence of other cases. Basilar meningitis occurs more especially in children affected with tuberculosis elsewhere, or who come of tuberculous stock. It has long prodromes, and a longer duration. Its symptoms are less acute and intense. It more frequently implicates the membranes of the spinal cord. Pachymeningitis is a disease of age. It occurs in drunkards, and in cases of dementia paralytica, chronic insanity, etc. It shows a more fluctuating course. It must be repeated again and again that the various forms of meningitis are to be sep- arated and recognized more by the etiological relations of the disease than by any difference in symptomatology. The Prognosis is far more grave than that of cerebro- spinal, but not so absolutely fatal as that of basilar menin- gitis. The great majority of cases terminate fatally, in coma or convulsions, in the course of from two to ten days. The Treatment of leptomeningitis does not differ in any way from that of any other form of meningitis; what little may be accomplished for the relief of symptoms will be mentioned under Cerebro-Spinal Meningitis, Hpidemic. The physician who is thoroughly indoctrinated as to the dangers of disease of the nose, of the accessory sinuses, and of the ear, and who is thoroughly familiar with the researches regarding the nature of infection, will prevent many cases of meningitis by timely treatment of the nose and ear, and by maintaining scrupulous asepsis in the management of all wounds of the skull. James T, Whittaker. George H. Malsbary. BRAIN, SOFTENING OF.—The brain is said to be softened when its consistency is less than that taken as a normal standard. Diminution of consistence, however, . shows but a part of the morbid work of an affection in which this phenomenon is only a circumstance quite ac- cessory to the more important cerebromalacia, and the term in its literal acceptation could apply only to a diminution of the cohesion of the brain tissues, while their other properties remained intact. Softening, being a symptomatic word with a pathological meaning, like the ‘word apoplexy, is rather a survival of a former belief, and its use is perhaps for this reason undesirable; but the name having been retained amid the fluctuations of opinions of writers on the subject, and in spite of its in- congruity and the fact that it is often applied to cases in which there is really no softening, it is now employed to designate a necrobiotic process that occurs in the elements of the brain tissues and that is consequent upon nutritive changes ordinarily attended by sensory, motor, and men- tal disturbances, which may vary according as the lesion is circumscribed or general in character. PATHOLOGICAL ANATOMy—Descriptions of the patho- logical changes accompanying occlusion of the cerebral arteries and the so-called encephalomalacia are compara- tively new. Their discussion is limited to contemporary authors, who have definitely settled certain points in- volved in the development of a new subject, notwith- standing diversity of opinica touching the nature and character of softening. In determining the question whether the diminished consistence or diffluence of cerebral substance be of pathological origin, two sources of deception should be guarded against; for this condition may be the result either of cadaveric decomposition or of accident happen- ing during the extraction of the brain from the skull. The genuine morbid appearances are then to be distin- guished from the artefacta produced by the investigator, and from the spontaneous changes occurring after death. Nor should the condition be confounded with diminished density or specific gravity. Normal white matter gives a specific gravity of 1.040, but when softened it is from six to eight degrees of the hydrometer scale lower than the normal condition; and the consistency of the brain is the same in individuals of all ages excepting the new- born and very young children. Season, temperature, and the disease to which the patient has succumbed affect this consistence. An epileptic, dying during a paroxysm, in the month of June, by asphyxia from the penetration of food into the respiratory ways, has been known to present at the necropsy, twenty-four hours afterward, a completely diffluent encephalon. In a second instance, forty hours after "death, with the same temperature, and in marasmus and an organic affection of the liver without cerebral symptoms, the brain was found to be in such a softened state that when it was placed on the hand the fingers penetrated by reason of its weight alone; while that of another cadaver, ex- amined seventy hours after death and twenty-four hours after the necropsy, was far from this state of softening. Though most frequent in old age, softening spares no period of life, its occurrence having been noted in the new-born and even in the feetus. That form peculiar to the senile condition appears to have served as a type in all the descriptions given by the best writers, who seem to have overlooked the pathological conformity shown in the failure of the nutrition as the primary and com- mon cause of cerebral softening at the two extremes of life. In the new-born the profound disturbance of nu- trition which, through the intermediary of the blood, disintegrates an organ whose softness has not yet been effaced by age, is essentially the same as that which in the senile state prepares for arterial and cardiac lesions, the formation of embolism or thrombosis, and the con- sequent incomplete irrigation of the cerebral substance by the blood. This starvation of the brain consequent upon diminished supply of arterial blood is now spoken of as necrobiotic and non-inflammatory in its nature. Such terms, however, as cerebral infarction and necro- biosis, though establishing facts, do not explain the phenomena of cerebral disintegration. Certain observers recognize in brain softening inflam- mation of an absolute kind; some regard it as a morbid state analogous to senile gangrene; others see a vital lesion affecting the nutritive integrity of the brain; while still others consider it asa lesion of nutrition owing to local ischemia, provoked by arrest or diminution of circula- tion either in one of the cerebral arteries or in the capil- laries of the brain. This profound trouble of nutrition, the essence of which is unknown, may occur as a primitiye necrobiosis of the brain substance, or this necrobiosis may be pre- ceded by a vascular lesion that causes a want of supply of blood effected through embolism, the local formation of a thrombus, or by compression of the vessels. If a cerebral vessel be stopped, that part of the brain supplied by the vessel is suddenly deprived of nourishment, and 395 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. $s this will be definitely the case if the embolism remains in place. When the vessel in question is a terminal artery, which does not exchange blood with other arteries, there will be immediate stoppage of cerebral function, followed by rapid changes of the brain elements, into fat and eventually into the liquescent state. The anatomical characters and circumstances that pre- side at the evolution of cerebral softening have been fairly made out. Observations in this direction warrant the statement that the arteria fosse Sylvit sinistre is most exposed to embolic occlusion, which circumstance may be explained anatomically by the difference in the angles at which the left carotid and the innominate arteries are given off by the aorta. For this reason the left carotid is liable to catch an embolus coming from the heart, and the left Sylvian artery being the terminal artery in ques- tion, the regions provided by this vessel are consequently most in danger of being affected by the embolic process. These regions are the nucleus lenticularis, the terminal nuclei in part, the external capsule, and part of the in- ternal capsule. The terminal branches of this vessel supply the second and third frontal convolutions, the island of Reil, and proximal surroundings, these being the portions of the brain most likely to suffer from the necrobiotic process. Further anatomical changes in the cerebral substance may result from the formation of an autochthonous coagulation, in consequence of degenera- tion of the intracranial vessels. Circumstances favoring the rapid formation of the thrombus are diminished motor force of the heart, roughening of the inner walls, narrowing and loss of force and elasticity of the vessels. Tumors of rapid growth, and inflammatory processes and their surroundings, which compress the vessels to such an extent as to lead to softening, are phenomena often observed in connection with softening. Occasion- ally the affected vessel is discovered entirely empty at the post-mortem examination, and for this reason it is supposed that the occluding mass has been reabsorbed. The first fact of importance in connection with the pathological details of softening is the infrequency of anatomical changes in the cerebral substance when the seat of obstruction is on the cardiac side of the circle of Willis, which permits the prompt re-establishment of the circulation on account of its free anastomosis. If, how- ever, the embolus is lodged in one of the terminal arteries of the basal arterial system, and a large region be thereby deprived of the necessary supply of fresh blood, there will be flowing back from the veins, and the tissues will become hyperemic and cedematous, and filled with small extravasations known as hemorrhagic infarctions. In this simple necrobiotic change, the blood and coloring matter pass through the ordinary metamorphosis, the tissue of the brain swells and decays, leading to the rapid development of masses of granular cells, and finally to fatty emulsion. Later, the diseased focus may become reabsorbed and a cyst remain in the place of the soften- ing, but this is rare; in fact, such a result may never occur except in the case of a small focus of inflammation. The process is more often followed by red sanguineous infiltration and yellow softening. The color, depending merely upon the amount of blood in the tissues, is, how- ever, not an essential point, nor is sanguineous infiltra- tion always present, and yellow softening is sometimes observed without its presence. ErroLogy.—Although the etiology of the large group of clinical symptoms popularly known as brain softening touches one of the most delicate points of medicine, but little satisfactory is to be said regarding its remote causes. Among those which predispose more or less are old age (from fifty to eighty) or agedness, chronic alcoholism, syphilis, sexual excesses and fast life, Bright’s disease, acute rheumatism, the dartrous diathesis, chorea, scarlet fever, insolation, intense cold, intense and long-continued intellectual exertion, severe and protracted emotional dis- turbance, misery, fright, overwork and responsibility, the abuse of opium, menstrual troubles, and, according to some authorities, the puerperal state. The cachexias and the inopectic diathesis (that is, a tendency to embo- 396 lism, to thrombosis, and to coagulation of fibrin) are adjuvant causes, the importance of which should not be overlooked. Among negroes, the intertropical races, and the inferior races generally, softening and other forms of brain disease are infrequent, but the aptitude for such disease grows with the degree of perfection of the species. Women are less subject than men, principally for the reason that, being women, they do not undergo the strain and exhaustion of high brain energy and severe muscular labor, and are not so exposed as men to the poison and excitement of alcohol, syphilis, and tobacco. Brain softening is the pathological sequence of many different conditions; but the more important causes that bring about the results in question may be stated as fol- lows, when brought concisely together: endocarditis, through the production of movable products; myocar- ditis, through the formation of thrombosis in the heart; all processes in the lungs leading to coagulation or to the reception of septic material into the veins of the lungs; aneurism of the aortic arch; atheroma of the cere- bral arteries; tumors of the brain, and even encephalitic foci; syphilis of the brain; the accumulation of pigment and pigmentous flakes in the blood, in connection with severe cases of malarial intermittent fever; and capillary occlusion through drops of fat. Other sources are in- juries and inflammations of the bone, the occlusion brought about by pus cells or white corpuscles, and the blocking of the vessels by lime metastasis. Of the phenomena of the occlusion of the intracranial vessels usually preceding the encephalomalacia, it is im- possible to present a clinical picture in definite terms without going into the details of embolism, thrombosis, and hemorrhage, for full particulars of which the reader is referred to their respective headings. Although spoken of in the same connection, cerebral softening and occlusion of the cerebral vessels are not necessarily in- terdependent, since softening does not always follow occlusion, and for this reason there is a tendency among some to consider softening as a distinct pathological con- dition. SymptToms.—Softening of embolic origin always begins by the symptoms peculiar to encephalic effusion of blood, or to those of apoplexy, the word being taken in its traditional sense. In fact, the symptomsare so similar to each other that their differentiation may be a matter of great difficulty to the most experienced. The symp- toms that characterize the early period of Hmbolism are sudden. Without premonition the patient is seized with a sudden dizziness, or a momentary headache, and with an involuntary cry falls consciousless; motion and sensa- tion appear to be extinguished, and unilateral paralysis, generally of the right side, follows. The only apparent difference between the symptoms occasioned by em- bolism of a cerebral artery and those of hemorrhage is the more transient state of the unconsciousness. For this reason part of the symptoms are often spoken of as apoplectic. In some cases, when the symptoms are less distinct, the unilateral paralysis forms a prominent feature. Other cases are prominently marked by more or less dizziness, by the absence of coma, by convulsions, and. by unilateral symptoms. This seems chiefly the case when embolism occurs in a circumscribed smaller cortical region, or when the embolus is reabsorbed and the circulation restored. Vomiting sometimes attends the onset of the attack; at other times delirium of a transitory character occurs; and in many cases sudden aphasia results from the anemia produced in the speech centre by the embolic occlusion of the artery supplying that region. There seems to be diversity of opinion among observers regarding the state of the pupils during the onset of the attack; it is probable, however, that they vary in different cases. At the fundus of the eye there may be found papillary or retinal cedema. It is only in chronic senile cases that papillary atrophy occurs. Thrombosis of the cerebral vessels is usually attended by premonitory symptoms, as persistent headache, either diffused or localized, slight dizziness, a sense of general confusion, unilateral disturbances of sensation, and even REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, violent transient paresis. Further development of the trouble gives rise to excitement and active delirium, causing the patient to get out of bed at night and to commmit other unreasonable acts. Symptoms of de- pression may follow this period of excitement, the pa- tient becoming apathetic and answering questions with difficulty. His movements are slow; there is tendency to somnolency; and a notable decrease occurs in the psychic functions, this decrease being characterized mainly by failures of the reasoning process, and by a more or less compromised memory, both of which are shown in verbal amnesia and other dysphasic affections. The humor is changing and emotional, and later the mental and other symptoms may become those of local- ized cerebral disease generally. As the patient goes into greater decline there may be bed-sores, and he may die from these; from an intercurrent malady, as a cardiac, renal,or splenic complication, ora pulmonary phlegmasia ; or a new attack or some new lesion of the encephalon may carry him off. Generally the patient dies in a state of profound adynamia. The size and physiological im- portance of the occluded vessels determine the difference in the extent and duration of the symptoms. In freshand vigorous subjects the occlusion of a small vessel may be followed by recovery, if the collateral circulation be es- tablished before the stage of necrobiosis begins. How- ever, in most cases of autochthonous thrombosis that survive, the subsequent history is that of chronic local- ized brain disease, and of the motor, sensory, and intel- lectual disturbances that follow. The same may be said of embolic softening. Actual softening being fully estab- lished, the most prominent symptoms are permanent weakness, often persistent hemiplegia accompanied by athetoid spasms, and progressive mental weakness end- ing in paretic dementia. With the exception of the dis- turbances of vision, the affections of the special senses are the same as those that occur in connection with cere- bral hemorrhage. The same is true of the sensory, trophic, and vaso-motor disturbances. Sudden amaurosis from occlusion of the arteria centralis retinse has been observed to occur in some cases of embolism. Anzemia of the fundus has also been found; and certain observers attach much diagnostic importance to the arterial and venous hyperemia of the retinal vessels and to conges- tion of the optic disc. The paralyzed limbs are generally those of the right side, for the simple reason that the left Sylvian artery is oftener occluded than the right. Bilateral paralysis may, however, follow bilateral vascular occlusion. Since we are unable to offer any satisfactory explanation of either the presence or the absence of contractures of the paralyzed limbs, they can scarcely be regarded as of pathognomonic significance. Motor restlessness, though characteristic of the worst cases, is greatly influenced by heredity. A patient of bad nervous antecedents, with a spot of progressive softening in one of the corpora striata, may become noisy and restless and suffer from insomnia, while another, with no nervous heredity and under the same conditions, is quiet and manageable. As enfeeble- ment progresses, the motor symptoms are particularly noticeable in the paretic walk and aphasic speech, the latter resulting from a disturbance of the secondary co- ordination consequent upon a lesion of the basal motor ganglia. (See Aphasia.) A brain affected by softening being on the verge of dissolution, the most prominent and troublesome symp- tom is the disturbance of the mental functions. The faculty most prone to failismemory. The vesicular neu- rin not being susceptible to the impression of events, the patient is unable to recall recent experiences and impres- sions with distinctness. The destructive metamorphosis of the convolutional structure is further shown in the impairment of the reflective faculty or power of judg- ment; and as the cerebromalacia progresses the patient may become whimsical and peevish, or his affective power may be deadened, and the intellectual faculties may de- cline into childishness or gatism and finally become ex- tinct. The occurrence of these mental changes in connection with the situation of the brain lesion may be further studied under other headings (see Brain Diseases : Diag- nosis of Local Lesions, and Brain: Functions of the Cerebral Cortez). DraGenosis.—The diagnosis of cerebral softening should be based upon the history of the case and the proving of such fundamental conditions as may produce hemorrhage and embolism or thrombosis. Hemorrhage cannot be distinguished from thrombosis by any absolute means, notwithstanding the various diagnostic signs that have been proposed at various times; but the condition of softening may be established with a probability border- ing on certainty when the associated symptoms are taken into account. When the premonitory symptoms have continued for a long time, the so-called apoplectic ac- cidents point to cerebral hemorrhage rather than to em- bolism, but the symptoms in all probability may be owing to thrombosis. Gradual march of the paralysis indicates thrombosis rather than cerebral hemorrhage. The rapid appearance or disappearance of the attack, and the situation of a centre of softening in the left hemisphere, point rather to embolism than to thrombosis. It can also be affirmed with almost entire certainty that the encephalic foyer is of embolic origin when the pres- ence of the symptoms permits us to suspect the forma- tion of splenic or of renal infarction. Such symptoms would be likely to occur aftera sudden attack in a young subject with an active bruit de souffle and enlargement of the spleen, pains in the lumbar region, and the pres- ence of blood in the urine. Cerebral softening may be confounded with hemorrhage, encephalitis, hematoma of the dura, and with tumors. In tumors the speech and intellect are generally unaffected, and there is pain with convulsions, vomiting, double optic neuritis, and choked disc; in hematoma the history of the case is the main reliance in making out a correct diagnosis; while in encephalitis there is a considerable rise in temperature and the evidence of tissue action in the respective region of the brain, which is notably absent in softening. The lowering of temperature, almost constant at the outset of cerebral hemorrhage, is absent in softening; aphasia is more frequent; paralysis of a mobile character in- creases by abrupt stages, and death may occur during the initial coma. The signs of arterial atheroma are of no value. PRoGNoOsIS.—Softening of the brain, more or less grave according to the extent and intensity of the functional troubles, is a disease that ends in death after a certain time, varying from a few days to several months or years. More die of the acute than of the chronic form. Some think the malady curable, but it leaves ineffaceable marks in the most favorable cases, and the reported re- coveries are to be looked upon with a great deal of doubt. They are said to have occurred in young and vigorous subjects; and when it is taken into considera- tion that the symptoms may have been incorrectly ob- served, or that they may have been those following vari- ous depraved states of the nervous system, the statement becomes more problematical. When not carried off by the initial symptoms, the patient is left with an incurable infirmity, in one of the most unfavorable conditions known. With the gradual enfeeblement of the intellect he is constantly threatened with new symptoms, and the reproduction of the original causes that produced the centre of softening. In fact, these causes greatly influ- ence any forecast that it is possible to make concerning the march and duration of the malady. As a rule, it may be said that the indications are the more favorable in simple circumscribed embolism, and most unfavorable in cases of autochthonous thrombosis. The prognosis is worse when there is slight impairment of the intellect, sensibility, and motility taken together than it is when any one of these singly is profoundly impaired. A case may be regarded as hopeless as long as the underlying cause of the attack remains, and extreme gravity is to be attached to such symptoms as rise of temperature and bed-sores. 397 Brain. Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. TREATMENT.—The causes that produce softening are difficult to remove and the therapeutical treatment of their effects is generally barren in results, notwithstand- ing correctness of diagnosis and the most judicious efforts to meet symptoms as they occur. Once established, senile softening is not amenable to treatment, Preven- tive measures being out of the question, except when the premonitory symptoms have continued for a long time, a consideration of the causes becomes fundamental matter, and the state of the heart and its action the main question. A declivous position of the head and perfect rest in a uniform temperature are advisable dur- ing an acute attack, while the body should be kept warm by artificial heat, warm clothing, and the cautious administration of stimulants. The caution in regard to stimulation is the more to be observed if there be the least suspicion of hemorrhage. In such a contingency it is deemed wise to act as if the case were one of cere- bral hemorrhage, since hemorrhage is more likely to oecur than occlusion, and the harm following stimula- tion in such a case seems to justify the diagnostic doubt. Symptoms pointing to a severe collateral hyperemia may be treated with large doses of the bromides, sina- pisms, dry-cupping, and mild purgation. The actual cautery and bleeding are to be avoided; but when there is general vascular irritation, leeches may be applied to the anus and behind the ears, in connection with intestinal revulsives and cold applications to the head. Digitalis, or strophanthus with glonoin, and amyl nitrite, are in- dicated, if the arterial tension be weak. Their use is, however, inadvisable in old persons. Recourse may be had to nervine tonics and to mild forms of slow deriva- tion after the attack has passed. The diet should be strictly regulated, all intellectual effort should be inter- dicted, the integrity of the nutritive functions should be maintained as much as possible, and the methods of treatment applicable to the chronic symptoms of circum- scribed cerebral disease should be generally observed. Irving C. Rosse. BRAIN, SURGERY OF THE.—History.—AlIthough in 1871 Broca located a cerebral abscess in the speech centre, and greatly relieved the patient by trephining, modern brain surgery begins properly with a modest report of a case by Macewen in the Glasgow Medical Journal for 1879, xii., 210, and a later more elaborate paper, by the same author, in The Lancet for 1881, ii., p. 541. In these papers he narrates three cases, occurring in 1876 and 1879, in which cerebral disease was located by focal symptoms. The first was a case of convulsions of the face, arm, and leg, in the order named, following a fall on the right side of the head. A trephine opening of the dura evacu- ated two ounces of blood, and the boy recovered without any febrile movement. In the second case the symptoms pointed to a lesion of the frontal lobe, and, after trephining, a tumor of the dura mater was dissected out. The patient died eight years subsequently from Bright’s disease. The third was a case of cerebral abscess, existing not at the site of a prior injury marked by a distinct cicatrix, but correctly diagnosticated in a totally distinct position, that is, in Broca’s convolution, by the focal symptoms. The parents declined an operation, and the child died. After death an operation was done precisely as it would have been done during life, and an abscess was found, the size of a pigeon’s egg, at the spot indicated by the localizing symptoms. In spite, however, of. this remarkable paper, the sur- gical world seemed blind to its opportunity. But in The Lancet for December 20, 1884, Dr. Hughes Bennett and Mr. Godlee narrated a case of subcortical tumor of the brain, diagnosticated by the localizing symptoms alone and before operation. When the dura was opened no tumor was visible: but so certain were they that a tumor existed that an incision was made in the apparently healthy brain tissue, and a morbid growth the size of a walnut was found one-fourth of an inch below the sur- face. This case, though ultimately unsuccessful because 398 of suppurative meningitis, instantly arrested the atten- tion of the surgical world by the precision of the diag- nosis, the success of the operative technique, and the evidence it afforded that we could successfully cope with heretofore hopeless cases. Its very failure, like the fail- ure of the first Atlantic cable, but pointed the way to success. The first American paper on cerebral tumor, by Hirsch- felder and Morse, of San Francisco, appeared in the Pacific Medical and Surgical Journal for April, 1886. The case was that of the successful localization, but un- successful removal, of a brain tumor. Two most remark- able papers on brain surgery, however, were published soon afterward by Mr. Victor Horsley, in the British Medical Journal for October 9, 1886, and April 23, 1887. In these papers ten cases were related, all of which were correctly localized; only one died, and the remainder were either benefited or cured. These were in part cases. of removal of brain tumor and of portions of diseased brain tissue the cause of epilepsy, and in part cases of trephining for relief of intense headache, ete. In this country, besides many excellent publications that I have not space or time to enumerate, the most noteworthy early papers published have been those by John B. Roberts, read before the American Surgical As- sociation in 1885; two by R. W. Amidon, in the Medical News for January 21, 1884, and the Annals of Surgery, vol. i., 1885, both of these authors making strong pleas for early and more heroic surgical interference in affections of the brain; and one by Seguinand Weir, in the Ameri- can Journal of the Medical Sciences for July, August, and September, 1888. I have also published several papers to which I may allude; the earliest two appeared in the American Journal of the Medical Sciences for October and Fic. 995.—Skull Showing Points Named by Broca. IV, Nasion (junction of the nasal and frontal sutures); G, ophryon (on a level with the superior border of the eyebrows, and corresponding nearly to the glabella, the smooth swelling between the eyebrows); B, bregma. (junction of the sagittal and coronal sutures); Ob, obelion (the sagittal suture between the parietal foramina) ; L, lambda (junction of the sagittal and lambdoidal sutures) ; J, inion (external occipital protuberance) ; the basion is the middle of anterior wall of foramen magnum; As, asterion (junction of the occipital, parietal, and tem- poral bones). g, gonion (angle of the lower jaw) ; S, stephanion (or, better, the superior stephanion, intersection of ridge for temporal fascia and coronal suture); S’, inferior stephanion (intersection of ridge for temporal muscle and coronal suture); P, pterion (point of junction of great wing of sphenoid and the frontal, parietal, and squamous bones). This may be H-shaped, or K-shaped, or “retourné,” in which the frontal and temporal just touch. November, 1888, and in the Medical News for December 1, 1888. In Germany perhaps the most elaborate and important publication is von Bergmann’s Hirnchirurgie. In addition to these, Mr. Horsley published, in the British Medical Journal for June 16, 1888, an account of the removal of a tumor from the spinal cord, and Dr. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, Macewen (British Medical Journal, August 11, 1888) published six cases in which the posterior arches of the vertebra had been removed for tumor and compression of the cord, and for an abscess in the posterior medias- tinum, two of which (paraplegia from Pott’s disease and fractured spine) had been published as early as 1886 (Glasgow Medical Journal, xxv., 210.) (See article on Spine, Surgery of the.) I shall refer in the course of this paper to a number of other publications, but I have thought it right to sketch thus briefly the early historical development of the sub- ject. ; Two things have made such brain surgery possible. First, the accurate localization of the functions (especially the motor centres) by Ferrier, Horsley, Fritsch, Hitzig, and others, by means of which we can with fair accuracy determine the site of a tumor, ab- scess, cyst, etc., by the focal symptoms. Secondly, the impunity with which we can trephine and open the dura mater, and inter- fere with the brain tissue itself, due almost entirely to the introduction of antiseptic surgery. To Horsley more than to any one else we owe the formulation of rules for suc- cessful brain surgery—rules which will be given at length hereafter. The Danger of Trephining.—For the tech- nique of trephining I refer the reader to the paper under that head in a later volume. But it is important further to consider the ques- tion of the danger involved in this opera- tion. In St. Bartholomew’s Hospital Reports for 1882, Dr. Walsham published a paper en- titled “Is Trephining of the Skull a Dangerous Operation per se?” In this article he analyzes 686 cases, of which 417 survived, the mortality, therefore, being 39.3 per cent. Dividing these large numbers into classes: first, those in which preventive trephining was used (nearly all for frac- ture), there being no cerebral symptoms, the mortality was 21.9 per cent. ; second, trephining in which severe cerebral symptoms existed, the mortality was 48.4 per cent. ; third, trephining in which moderate cerebral symptoms were present, the mortality was 27 per cent.; fourth, late trephining, mostly after inflammation had set in, the mortality was 58.5 per cent.; fifth, secondary trephin- ing showed a mortality of 22 per cent. Walsham showed that in 122 cases of late trephining, in which there was no condition endangering life, only 10.6 per cent. died. Amidon, in the paper referred to, analyzes 100 cases of trephining reported since 1879, in most of which antiseptics were employed. Of these 100 cases 26 died, but of these 23 presented at the time of operation symptoms already endangering life. He there- fore concluded (and most later writers practically concur in his conclusions) that the mortality of trephining per se is but 3 per cent., a conclusion which would seem to be confirmed by Pruniéres and Robert Fletcher, by their investigations, which show the frequency of recovery in cases of prehistoric trephining. Seydel (“ Antiseptie und Trepanation”) even estimates the mortality as only 1.6 per cent. Not only have antiseptics thus diminished the danger of simply opening the cranium, but the numerous cases’ which have been reported of opening the dura, even when followed by removal of tumor or of some brain sub- stance, clearly show that only moderate danger is add- ed in any case by such surgical procedures. “ Hereto- fore,” says Amidon, “the reluctance of the surgeon to open the cranium seems avidity as compared with his hesitation in piercing the dura mater. The cerebral cor- tex seems to be a ‘dead line’ inside the prison walls of conservative surgery, across which even the most daring are tempted or the most unwilling are dragged only by sure indications or desperate chances.” The future danger seems to be, however, that temerity may take the place of timidity, and that many patients will either die or go about with multilated brains that on ought never to have been touched. This word of cau- tion, therefore, at the outset may not be out of place. TOPOGRAPHY OF THE BRAIN IN Its SuRGICAL RELA: TIons.—The relation of the chief fissures and convolu- Fic. 996.—View of the Brain from Above. fF’, Frontal lobe; P, parie- tal lobe; O, occipital lobe; S, end of the horizontal branch of the fissure of Sylvius; c, central fissure or fissure of Rolando ; _A, an- terior central or ascending frontal convolution ; B, posterior central or ascending parietal convolution; F, upper, #2, middle, F'3, lower frontal convolution ; f;, superior frontal sulcus; fo, inferior frontal sulcus ; f3, vertical fissure (sulcus preecentralis) ; P,, upper or pos- tero-parietal lobule ; P2, lower parietal lobule, constituted by Po, supramarginal gyrus ; P2’, angular gyrus; tp, intraparietal sulcus ; cm, calloso-marginal sulcus ; po, parieto-occipital fissure ; t,;, upper temporal sulcus; 0, first occipital convolution; 0, transverse occip- ital sulcus. (Ecker.) tions of the brain to the surface of the skull is of the greatest possible importance. It is essential that we shall be able, from fixed landmarks on the skull, to locate the various fissures and convolutions, and by them the: various cortical centres. The subject has been studied by Reid, Horsley and Hare, Krénlein and others, each of whose methods of research has its own merit. I shall give a brief outline of the four methods, and in doing so I must take it for granted that the reader is fairly well acquainted with the chief outlines of the cerebral cortex. In order, however, to facilitate the study of the external topography of the brain, I have introduced cuts. First: Fig. 995, from Broca, giving the points named upon the skull. Secondly: Figs. 996-998, from Ecker, giving the names of the principal sulci and convolutions. I have also appended two figures from Ferrier’s “ Func- tions of the Brain” (Figs. 999 and 1000) in order to fix as nearly as possible the relations of the various centres, so. far as known at present. The figures in these two cuts are placed as follows: 1, On the postero-parietal lobule (precuneus), the centres for movements of the opposite leg and foot in locomotion. 2, 3, 4, At the upper end of the fissure of Rolando, and hinder part of the first frontal convolu- tion, the centres for various complex movements of the 399 Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. arms and legs, as in climbing, swimming, etc. In this | the centre for hearing. a, b, ¢, d, On the ascending area Horsley states that the arm and leg of the same side | parietal (post-Rolandic) convolution, indicate the cen- are involved together. 5, At the posterior part of the | tres for movements of the fingers and wrist. The cen- c 7 cm F : vw” z ; ‘ Fic. 997.—Outer Surface of the Left Hemisphere. F’, Frontal lobe; P, parietal lobe; O, occipital lobe ; 7, temporo-sphenoidal lobe; S, fissure of Sylvius; S’, horizontal, S", ascending ramus of the same ; ¢, central sulcus or fissure of Rolando; A, anterior central or ascending frontal convolu- tion ; B, posterior central, or ascending parietal convolution ; F'1, superior, F’?, middle, and F'3, inferior frontal convyolutions ; f!, superior, f?, inferior frontal sulcus ; £3, preecentral sulcus; P?, superior parietal or postero-parietal lobule ; P?, P%, inferior parietal lobule, viz. : P?, supramar- ginal gyrus; P®, angular gyrus; ip, intraparietal sulcus ; em, termination of the calloso-marginal fissure ; O}, first, O?, second, O%, third occipital convolutions ; po, parieto-occipital fissure ; 0}, transverse occipital sulcus; 02, inferior longitudinal occipital sulcus; 7"), first, 7'2, second, T3, third temporo-sphenoidal convolutions ; t’, first, t?, second temporo-sphenoidal sulci. (EcKer.) tre for smell is situated in the hook of the hippocampal region (Fig. 998, U). In close proxim- ity, but not exactly defined as to limits, is the centre for taste. The centre for touch is situated in the hippocampal region (Fig. 998, H) and gyrus fornicatus (Gf). To these I also add Figs. 1001 to 1009 from Horsley’s article (Amer. Jour. of the Med. Sciences, April, 1887) for the same pur- pose. I also add a figure from Gowers (Fig. 1010) to show the relations of the convolutions to the skull. The reader desirous of further information will find it briefly stated in the American edition of Gray’s “ Anatomy,” for 1887, p. 681, or very fully in the works of the authors already referred to, together with Ferrier’s “Functions of the Brain.” (See also article Skull, etc.) It must be borne in mind that, as pointed out by Stokes, the relations between the brain and the skull vary at different ages, a fact reinforced by Cunning- ham’s models of the brain hard- ened 77 sttw, and then exposed by removing the bones of the skull, leaving bridges at the sut- ures. Symington points out that the Sylvian fissure lies much higher above the squamo-pari- etal suture in the child than in the adult, and is from half an superior frontal convolution—extension forward of the | inch to even an inch above it. He thinks that they at- arm and hand, as in putting forth the hand to touch | tain the adult relations at about the eighth or ninth year. something in front. 6, On the ascending frontal (pre-Rolandic) convolution, just behind the up- per and hinder end of the mid- dle frontal convolution—move- ments of the hand and forearm in which the biceps is particu- larly engaged, viz., supination of the hand and flexion of the forearm. 7 and 8, Respect- ively for the elevators and de- pressors of the angle of the mouth. 9 and 10, As one, mark the centre for movements of the lips and tongue, as in speech. This especially occu- pies the posterior portion of the inferior frontal (generally known as Broca’s) convolution. Dis- ease of this region on the left side produces aphasia. i1, The centre for the platysma, retrac- tion of the angle of the mouth. 12, A centre for the lateral movements of the head and eyes, with elevation of the eye- A @ lids and dilatation of the pupils. Frc. 998.—Inner Surface of the Right Hemisphere. CO, Corpus callosum, longitudinally divided ; 18 and 13’, On the supramar- Gt, gyrus formes Hy, gyrus Py pea A) 0s ripe hippocarint or yrinces fissure ; U, unci- . Se nate gyrus; cm, calloso-marginal sulcus ; , Median aspect of the first frontal convolution ; ¢, ginal lobule and angular syrus, terminal portion of the central sulcus, or fissure of Rolando; A, ascending frontal, B, ascending including also the occipital lobe, parietal convolution; Pe, paracentral lobule; Pl’, precuneus; Oz, cuneus; po, parieto-occipital indicate the centre for vision. fissure; 0, transverse occipital sulcus; 0c, calcarine fissure; oc’, superior, oc", inferior ramus of 14, On the superior temporo- sphenoidal convolution, indicates Ecker.) 400 the same; D, gyrus descendens; 74, gyrus occipito-temporalis lateralis (lobulis fusiformis) ; 75, yrus occipito-temporalis medialis (lobulus lingualis) ; cf, collateral or occipito-temporal fissure. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain. The fissure of Rolando is also much more oblique in its direction (52°, Hamy) in the child, and lies farther forward on account of the imperfect development of the Fig. 999.—Side View of the Brainof Man. (ferrier.) see pp. 399, 400). (For references frontal lobes. Gradually as these are developed, espe- cially the third frontal convolution, the lower end of the fissure is pushed back and assumes its adult angle and position. First: Landmarks on the Skull. Most of these are readily determined by reference to the foregoing figures, Fic. 1000.—'rop View of the Brain of grin ‘ Ferrier.) (For references see pp. 399, 4! but there are some which must be more minutely de- scribed. The temporal ridges (Fig. 995) are two in number: the upper for the temporal fascia, the lower for the upper border of the temporal muscle. The upper is the better marked, and can be easily followed by the finger from the external angular process backward. It marks the sudden change in the slope of the skull, from the curve of the upper surface to the more vertical direction of the Vou. II.—26 ' side. ‘The lower one is best made out by closing and re- laxing the jaw, when the upper edge of the tempora! muscle can be located by the finger. Like the upper, it begins at the external angular process, but runs at a lower level than the fascial ridge. Its middle is about two-fifths of an inch below it. The points where the Fig. 1001.—Representation of the Centre for the Upper Face and Angle of the Mouth. (Horsley.) coronal suture crosses these two ridges are called re- spectively the upper and the lower stephanion (Fig. 995, Sand S’). The coronal suture starts at the bregma (Fig. 995, B). Drawing the bi-auricular line (Fig. 995), measurements on 185 skulls have given me as a mean result, that in the adult the bregma lies 0.875 of an inch in front of this line. Fig. 1002.—Representation of the Centre for the Vocal Chords (Adduc- tion). (Horsley.) The greatest distance was1.2 inch. In 16of these skulls, the bregma coincided with the point where the bi-auricu- lar line crosses the sagittal suture. In only 7 did it lie behind it, the maximum being 0.9 inch. Starting from the bregma, by shoving the scalp backward and forward, the finger can perceive (but with some difficulty, espe- cially in the aged) the irregularities of the coronal suture, Fig. 1003.—Representation of the Centre for the Lower Face and Floor of the Mouth. (Horsley.) but toward the stephanion they become more marked and can be pretty well appreciated. The parieto-sguamosal 401 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. suture lies beneath the temporal muscle. The highest point of its curved line is at the junction of the upper and middle thirds of a vertical line drawn from the upper Fic. 1004.—Representation of the Centre for the Shoulder. CHorsley.) border of the zygoma to the ridge for the temporal muscle in front of the temporo-maxillary articulation. The point of junction of the great wing of the sphenoid, frontal, parietal, and squamous bones is called the pterion (Fig. 995), and is about half-way between the superior stephanion and the zygoma. It is usually H-shaped. The Relation of the Fissures and Convolutions to the Fig. 1005.—Representation of the Centre for the Elbow and Wrist. (Horsley.) Landmarks on the Skull.—There are five great fissures of the brain to be localized: First, the great longitudinal fissure separates the two hemispheres of the cerebrum. This does not lie precisely in the middle line, but in consequence of the slightly larger size of the left hemisphere, it lies about an eighth of an inch to the right of the middle line. Second, the great transverse fissure, or the fissure of Fic. 1006.—Representation of the Centre for the Thumb. (Horsley.) Bichat, between the cerebrum and the cerebellum. This lies in a line from the external auditory meatus to the tnion (or external occipital protuberance). This marks also the position of the tentorium and of the lateral sinuses. The other three great fissures (viz., the fisswre of Sylvius, the fissure of Rolando, and the parieto-occipital fisswre) may be located by the following rules, 402 Horsley’s Method.—The fissure of Rolando, in relation to the motor region, is the most important in the whole brain. As will be seen by reference to Figs. 996 and 997, Fic. 1007.— Representation of the Centre for the Combined Synchron- ous Action of Both Limbs. (Horsley.) almost all the motor centres lie clustered about it. As Thane has shown, it runs downward and forward from a point half an inch behind the middle of the distance from the glabella to the inion. This point being fixed, if a line be drawn laterally at an angle of 67° (as shown THT Fig. 1008.—Representation of the Centre for the Lower Limb. H, Fo- cus of representation of the hallux. (Beevor and Horsley.) by Hare) for a distance of three and three-eighths inches, it will indicate the fissure of Rolando; the lower third of the fissure, however, changes to a somewhat more verti- cal direction, thus forming a knee-like bend. To fix this important fissure, Horsley uses a strip of metal or of parchment paper, say fourteen inches long, with a sec- ond strip firmly fixed to it at an angle of 67° (Fig. 1011). Fa. 1009.—Representation of the Centre for the Head and Neck, to- gether with Conjugate Deviation of the Eyes. (Horsley.) The zero point of the scale of the longer piece (as sug- gested by Dr. Morris J. Lewis, of Philadelphia) is placed half an inch in front of the angle formed by the two arms. From this zero point the scale (in quarter inches) . leads both forward and backward. The longer arm is placed in the middle line of the shaven head, in such a REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. position that the reading of the two scales at the glabella and at the inion shall be identical. The lateral strip will then mark the fissure of Rolando (three and three-eighths inches); the direction of the lower third being slightly changed, as above indicated. The fissure of Sylvius commences at the pterion, the anterior branch running upward and forward, continu- Fic. 1010.—Diagram of the Relations of the Convolutions to the Skull. 2, and 3, Upper, middle, and lower frontal convolutions; A F, A P, ascending frontal and parietal convolutions ; S P, superior parietal lobule ; Ang, angular gyrus; OcL, occipital lobe; 7'1, 2, 3, the temporal convo- lutions; P O F, parieto-occipital fissure; F' Sy and F' Sy P, tissure of Sylvius and its posterior limb; F’. Ro, fissure of Kolando. ing the line of the squamo-sphenoidal suture, but one or two millimetres in front of it. The posterior branch passes upward and backward half a millimetre above the squamo-parietal suture, as far as its highest point, and from there curves slightly upward toward the centre of the parietal eminence, which it nearly reaches. This fissure limits the motor region anteriorly by its anterior limb, and postero-inferiorly by its posterior limb. The precentral or vertical suleus is of great importance also, as it divides two convolutions of very different functions, and on each side of it has convolutions of great motor importance. It runs parallel to and just behind the coronal suture, and is al- most vertical to a horizontal tangent (74 #1, la Plea Pll a A at the bregma; hence its second name. Its upper end reaches to the level of the middle of the fissure of Rolando. From it, about ona level with the superior stephanion, the inferior Frontal sulcus runs forward. Above the origin of this latter sulcus, the precentral sulcus continues vertically half-way across the root of the middle frontal convolu- tion. Its lower end is separated from the fissure of Syl- vius by a horseshoe-shaped convolution of great im- portance (the operculum), which is nearly always one centimetre wide, and overlies the island of Reil. The superior frontal sulcus starts from the ascending frontal (pre-Rolandic) convolution midway between the fissure of Rolando and the line of the precentral sulcus. Its posterior end, therefore, lies behind the precentral sulcus. The superior and inferior frontal sulci run for- ward and slightly downward, practically parallel with the great longitudinal fissure. The intraparietal sulcus lies behind the fissure of Ro- lando, and bounds the motor area posteriorly. It begins opposite the knee-like bend at the junction of the middle and lower thirds of the fissure of Rolando. As it goes upward it lies about midway between the line of the Ro- landic fissure and the parietal eminence. It then sepa- rates farther from the fissure of Rolando, and so widens HY, (Gowers. ) Brain, Brain, the area of the ascending parietal (post-Rolandic) con- volution that its upper end is known as the superior parietal lobule. In the middle of its course it runs about parallel to the great longitudinal fissure, and midway between it and the parietal eminence. Farther on, it passes by the external end of the parieto-occipital fissure and goes downward and backward into the occipital lobe. The parieto-occipital fissure on the upper surface of the cerebrum is a short fissure about an inch long, at right angles with the great longitudinal fissure, and two or three inches in front of the lambda (the junction of the lambdoidal and sagittal sutures) (Fig. 995, Z). This fissure, on the median surface of the cerebrum (Fig. 998, po), is a long fis- sure running downward and forward. It is joined at its middle by the calcarine fissure (Fig. 998, oc). Between these two fissures is the cwneus (02, Fig. 998), in which lies the cortical centre for sight. In- jury to the cuneus, therefore, produces blindness in the half of each retina on the side corresponding to the injury (hemianopsia). In front of the parieto-occipital fissure, on the middle surface of the hemisphere, lies the precuneus or quadrate lobule (Fig. 998, P;'), bounded in front by the upper end of the calloso-marginal fissure (em). In front of and behind the fissure of Rolando (Figs. 997 and 998) are two most important convolu- tions. The one in front is chiefly known as the ascending frontal or precentral, or, as I prefer to term it, the pre-Rolandic convolution. The one be- hind the fissure of Rolando is known as the as- cending parietal or postcentral, or, as I prefer to term it, the post-Rolandic convolution. At their up- per ends they fuse into the paracentral lobule, and at their lower into the operculum. The two frontal sulci divide the frontal lobe horizontally into three convolutions, viz., the first, second, and third, or respectively the superior, middle, and inferior frontal convolutions. The third or inferior convolution is frequently known as Broca’s convolution. On the left side the centre for speech is located (in left-handed per- sons this speech centre lies in Broca’s convolution on the right side). For the location of other centres in these various convolutions the reader is referred to Figs. 999- 1009. Below the intraparietal sulcus, between its beginning and the posterior limb of the fissure of Syivius, lies the supramarginal convolution (Fig. 997, P*). Below the posterior portion of the intraparietaly and behind the superior extremity of the horizontal limb of the Sylvian fissure, lies the angular gyrus (Fig. 997, P®). uj The temporo-sphenoidal lobe is divided horizontally, by the supertor and inferior temporal sulci, into three convolutions, first, second, and third, or sw- perior, middle, and inferior tem- poro - sphenoidal convolutions. On the median aspect of the hemispheres the calloso-mar- ginal fissure (Fig. 997) has above it the marginal convolu- tion; below it, and immedi- ately above the corpus cal- losum, lies the gyrus fornicatus. Reid’s Method.—Reid’s “ base line” (Fig. 1012) is a line run- ning backward from the infra- orbital ridge through the mid- dle of the external auditory meatus, and prolonged to the middle line of the head posteriorly. The fisswre of Sylvius runs from a point an inch and a quarter behind the external angular process of the frontal bone to a point three-fourths of an inch below the most promi- Fig. 1011.—Horsley’s Instru- ment for Fixing the Fis- sure of Rolando, as Modi- fled by Dr. Morris J. Lewis. 403 Re< Brain. Brain. nent point of the parietal eminence. Measuring from above backward, the first three-fourths of an inch will represent the main fissure; the rest indicates the hori- zontal limb. The ascending limb starts at a point three fourths of an inch back of the anterior extremity, that is, two inches behind and slightly above the external angular process, and runs vertically upward and forward about one-fourth of an inch. To find the fissure of Rolando, draw the base line and the lines for the great longitudinal fissure and the fissure of Sylvius. Then draw two lines perpendicular to the base line: one from the depression in front of the external meatus (Fig. 1012, D E) and the other (F G) from the posterior border of the mastoid process at its root. We shall thus have on the surface of the head a four-sided figure, bounded above and below by the lines for the longitudinal fissure and the horizontal limb of the fissure of Sylvius, respectively, and in front and behind by the two perpendicular lines just described. Next draw a diagonal line (F H) from the posterior superior angle to the anterior inferior angle. This corresponds to the fissure of Rolando, which, however, as a rule, does not quite join the fissure of Sylvius. Cunningham states, however, that this (Reid’s) mode of locating the fissure of Rolando is not reliable, and I much prefer Horsley’s, Krénlein’s, or Hare’s, both as more accurate and much more easily applied. To find the parteto-occipital fissure continue the line for the horizontal limb of the fissure of Sylvius (Fig. 1012, Sy.h.fis.) to the line of the longitudinal fissure. The por- tion of this line, about an inch long, next to the longi- tudinal fissure, will usually approximately correspond to it. The position of the various convolutions can now be readily indicated by reference to Fig. 1010. Hare's Method.—Mr. A. W. Hare has pointed out that neither the cranial sutures nor the prominences of the Fic. 1012.—A, Glabella; B, external occipital protuberance; e.a.p., external angular process of frontal bone; B C, transverse fissure ; A B, longitudinal fissure; Sy.fis., Sylvian fissure ; Sy.h.jis., horizon- tal limb of fissure of Sylvius; Sy.a.fis., ascending limb of fissure of Sylvius ; D, E, perpendicular line from depression in front of exter- nal auditory meatus to middle line of top of head; F, G, perpendic- ular line from posterior end of base of mastoid process to middle line of top of head ; F, H, fissure of Rolando ; .o.fis., parieto-occipi- tal fissure ; +, most prominent part of parietal eminence. (Reid.) face are available for mapping out the brain; the former, because they are too indistinct or obliterated, the latter, because they have no direct relation to the cranium as a whole on account of the unequal development. The same observation, he points out, is true of the bony land- 404 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. marks on the lower portion of the skull. If the external auditory meatus or the mastoid process has lines drawn from it over the convexity of the skull, they will give inconstant results according as the anterior or posterior portions of the head are more or less developed. Four Ton gitud fis. Sore meee 1c, 4 ya on ‘} ) Fic. 1018.— +, Most prominent part of parietal eminence; a, convex line bounding parietal lobe below ; b, convex line bounding temporo- sphenoidal lobe behind; 1.fr.c., first frontal convolution ; 1.f7r.f., first frontal sulcus; f.R, fissure of Rolando; Sy.f., Sylvian fissure; Sy.h.f., horizontal limb of Sylvian fissure; Sy.a.f., ascending limb of Sylvian fissure; p.o.f., parieto-occipital fissure; i.par.f., intra- parietal sulcus; ang.g., angular gyrus; 8.m.c., supramarginal con- volution ; 1.t.s.¢., first temporo-sphenoidal convolution ; 1.t.s.f., first temporo-sphenoidal sulcus; 1.0.c., first occipital convolution ; p.p.l., postero-parietal lobule. (Reid.) points, however, are of value, viz., (1) the glabella, which corresponds to the base of the anterior lobe of the brain; (2) the inion, which corresponds to the base of the pos- terior lobe of the brain, and also to the junction of the falx with the tentorium; (3) the third constant landmark is the external angular process of the frontal bone which limits the cerebrum laterally and has also a uniform relation to the fissure of Sylvius; (4) finally, the parietal eminence is valuable, since it marks the greatest lateral expansion of the brain and bears a special relation to the supramarginal convolution. While its cranial relations vary consider- ably, its cerebral relations are much more constant. The distance from the glabella to the upper end of the fissure of Rolando will be 55.7 per cent. of the total distance from the glabella to the inion. For instance: The distance from the glabella to the upper end of the Rolandic fissure will be— If the distance from the glabella to the inion is— 11 inches. 6.1 inches. 113° (Gk 12 6.6 sas 10h cae i. Oem 13 La 7 In other words, however the proportions of a head may differ, the pre-Rolandic and post-Rolandic regions of the brain are uniformly proportionate to each other, the pre-Rolandic being 55.7 per cent. and the post-Rolandic 44.38. Moreover, the fissure of Rolando runs downward and forward at an angle of 67°, and its average length is 32 inches. Dr. Claude Wilson, of Tunbridge Wells, has con- . structed a cyrtometer (Fig. 1014) consisting of two strips of flexible metal forming a letter T, with a tape to secure the short horizontal limb in place; the mode of using REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. which is shown in Fig. 1015. On the antero-posterior arm it will be noticed that there are two scales. The posterior scale is lettered in capitals from A to Q. The anterior scale is lettered in small letters from a to g, and they are so placed that when in position the distance from the glabella to small a, 0, c, etc., is 55.7 per cent. of the dis- tance from the glabella to capital A, B, C, etc. The horizontal limb being placed on the forehead, so that its inferior border corresponds to the glabella, if the capital letter A falls over the inion, then the small a will corre- spond to the beginning of the fissure of Rolando, and so on for the other letters. The small strip for marking the fissure of Rolando is movable on the antero-posterior limb, and is also reversible to suit both sides. This is now slid along until it corresponds for instance to the small @, when its anterior border marks the line of the fissure of Rolando. Similarly, if the inion corresponds to B or C, the Rolandic strip is slid to 0 or ¢, ete. The Fissure of Sylwius.—To locate this fissure a line is drawn from the external angular process backward to the occipital protuberance (Fig. 1018, EAP to OPr) by the shortest route between these points. This line droops a little toward the external au- ditory meatus in avoiding the great convexity of the skull, which convexity lies in the course of the direct horizontal line between these two bony prominences. It usually passes about half an inch above the meatus, and thus closely cor- responds to the floor of the middle fossa at this point. In front of the me- atus it lies above the level of the floor of the mid- dle fossa; behind it, it runs parallel to, and nearly co- incident with, the attachment of the tentorium and the - posterior half of the lateral sinus. A point one inch and a half posterior to the external angular process on this line marks the commencement of the fissure of Syl- BY! Fig. 1015.—Wilson’s Cyrtometer in situ. G, Glabella; EAP, external angular process; R, fissure of Rolando, its position and direction marked by the lateral strip of metal. Fig. 1014.—Wilson’s Cyrtometer. Brain, Brain, vius. Even in heads of the most varied shapes and sizes this measurement remains constant. From this point a straight line to the centre of the parietal eminence marks accurately the course of the pos- terior limb of the fissure and nearly corresponds in part with the squamo-parietal fissure (Fig. 1018, SF). The ascending limb of the fissure corresponds closely with the squamo-sphenoidal suture in its entire length, and is continued upward in the same line for half an inch (A). The middle meningeal artery is also shown in Fig. 1018 in its relation to the Sylvian and Rolandic fissures. To expose the tip of the temporo-sphenoidal lobe, trephine behind the upper extremity of the great wing of the sphenoid (TS). To expose Broca’s convolution, trephine immedi- ately in front of the great wing of the sphenoid (B). iroenlein’s Method.—K. has recently proposed this simple and accurate method of locating the fissures (Fig. 1016): (1) The base line, ZM, runs horizontally at the lower border of the orbit and the upper border of the auditory meatus.* (2) Parallel with this, on a level with the supraorbital ridge, another horizontal line (KK’)is drawn. (3) An anterior vertical line (ZK) is drawn from the middle of the zygoma to the supra-orbital line. (4) A mid- dle vertical line is drawn from the. articulation on the lower jaw A, and prolonged to R. (5) A pos- terior vertical line is drawn from the posterior bor- der of the base of the mastoid (MK’) and prolonged to P, the middle line of the skull. (6) Draw a line from K toP. Be- tween the points R and P’ it cor- responds to the fis- sure of Rolando. (7) Bisect the angle PKK’ by the line KS. This line corresponds to the fissure of Syl- vius from its bifurcation to its posterior end. The point K is over the bifurcation of the fissure of Sylvius. K and K’ are the points for trephining to reach the anterior and posterior branches of the middle meningeal artery. The method applies equally to all varieties in the shape of the head, both brachi- and dolicho-cephalic. Chiene’s Method.—Mr. John Chiene, of Edinburgh, has proposed a method of fixing the position and length of the Rolandic fissure which is at once simple, ingenious, Fig. 1016. and always available. He folds a square piece of paper once (Fig. 1017, A, B, C, D), on the diagonal line A, C. The angle B A C is then evidently 45°. The angle DAC (45°) is then halved (22.5°) by folding the paper again on the line A E. The sum of the angles B A CandC A E° * I perhaps ought to state here that in different parts of this article I have utilized to a small extent portions of the text contributed to other publications. 405 Brain, Brain, is evidently 67.5°, which is near enough for all practical purposes to the angle of the fissure of Rolando. The side A Bis then applied to the middle line of the head, the point A being placed half an inch behind the midpoint between the glabella and the inion, when the line A E will cor- respond to the fissure of Rolando. But it must be re- membered that how- ever exact our cerebral localization may be, there are exceptional cases that setat naught all our present knowl- edge on this subject. Thus Cunningham re- ports a case of subar- achnoid cyst extend- ing from the fissure of Rolando to the occip- ital lobe with neither motor nor sensory dis- turbance, and Bramwell reports a case of sarcoma of the dura destroying the greater part of the motor centre with- out any paralysis. These and a number of other such cases should make us careful not to be too dogmatic until we learn much more. Percussion of the Skull.—Here, perhaps, as well as else- where, may be noted a point to which Macewen has called attention, viz., that percussion of the skull may afford valuable evidence not only of the condition of its contents, and, as I have pointed out, of that of the skull itself, but also, as I have observed in one case, of the condition of the overlying tissues. Macewen does not state the character of the percussion note, but presumably it is that, when an abscess or tumor exists, there will be a local, increased dulness on per- cussion, with a lower tone. He states that it has been verified post mortem, and that it will probably be of especial value in early life in the diagnosis of tumors of the cerebellum. In a case of hydrocephalus I have observed a markedly increased dulness of one side on per- cussion, and the autopsy showed that the ventricular distention was far more marked on this side. In simple fracture of the skull, hydrocephalus, and large tumors, the “cracked-pot ” sound described on page 421 of this paper may be of service, and I would urge that it be tested and reported on in future cases. In a case of syphilitic necrosis of the skull above the left ear, with a Jacksonian epilepsy in the left arm and leg, and therefore a presumable lesion (gumma?) on the right side of the brain, I have tested the percus- sion note. Over the necrosed bone the tissues were somewhat thickened, but not to any excessive degree. The percussion note was so much duller on the left side, half-way between the sagittal suture and the ear, that two of my assistants with their backs turned to the pa- tient correctly stated which side was percussed, and the same difference was noted as between the same site and the forehead well above the frontal sinus. In a paper published in 1884, I have pointed out the similar value of percussion in the so-called abscess in the frontal sinus and the antrum. GENERAL TECHNIQUE OF OPERATIONS ON THE BRAIN. —This has been carefully formulated by Horsley. In a few minor points I have added to it from my own personal experience, as well as from that of others. I. Shaving the Head.—This is not only important for the operation, but should always precede a definite diag- nosis, and, in fact, be one of the means of making it. So important do I regard this that I should consider no diagnosis as assured, and no operation warranted, that had not been preceded by shaving. The unexpected and the unknown scars found have surprised me in several cases. Besides this, no reliable mapping on the head of the fissures and convolutions can otherwise be made. Ur-------—---------------- e/aielors orebelaysloyave el-elelels!aialels /acola/ elie Meas 4 —1.0 PIDTOUMI ACs ora k ce ecltiinie eiaiel veletotets eraicreleisteretcversiaisce 3 Cholestestomiata soci meiislereteeissteete eer ietaeera aie ciske 2 TiO OMAP oss orarvis stelle clove lansrateistalele eksic eterelst= ree: Erectile or vascular tumors. 2 Dermoid cysts.. 2 Enchondromata . 3 1 Lymphomata...--....... 1 This shows that tuberculosis is nearly twice as common as any other one known cause. Tuberculous tumors are most frequent in early life, three-fourths of them occur- ring before twenty, and one-half before ten, years of age (Gowers). The various forms of malignant tumors exceed in number even those which are of a tuberculous nature. They are most common from twenty to forty. Other varieties, excepting hydatids and cysts, furnish each but asmallnumber. The small percentage of syph- ilitic gummata is rather surprising. Dr. Gowers states that of 637 intracranial tumors the distribution was as follows: Cerebral hemispheres (excluding the central ganglia), 297; cerebellum, 179; pons, 59; central ganglia, 48; medulla, 31; corpora quadrigemina, 13; crura cere- bri, 10. Starr, in a valuable paper on 300 cases of intra- cranial tumors in children, found 96 in the cerebellum. The Symptoms have been so carefully studied and so fully treated by Dr. Mary Putnam-Jacobi, in the present volume of this HANDBOOK (article on Brain, Tumors of), and by Dr. M. Allen Starr, in his article on Brain: Diag- nosis of Local Lesions (see p. 282), that it would be but a repetition here for me to consider them. Three points, however, ought to be more fully noticed, viz., disturb- ance of language, eye symptoms, and local tempera- tures. A most important paper in connection with disturb- ance of language is that by Dr. M. Allen Starr. Words in ordinary use have a complex mental substratum, made up of a number of mental pictures. These are, first, memory of the sound of a word as spoken; if this be lost we have “word deafness.” Second, memory of the appearance of a word as printed or written, if this be lost we have “word blindness.” Third, memory of the muscular movements made in writing a word; if this be lost the result is “agraphia,” or inability to write. Fourth, memory of the muscular movements made in pronouncing a word; if this be lost, although the vocal apparatus is perfect, it is known as “motor aphasia. ” Fifth, the word-hearing and word-uttering processes may be perfect, and the patient can understand what is said to him, and can pronounce words well, but the connection between the word-hearing and the word- uttering processes is broken, and the patient misplaces words or uses one word for another—for instance, call- ing the “four of spades” the “five of telephone.” This is known as “ paraphasia,” or the aphasia of conduction of Wernicke. The lesion in these cases usually involves the island of Reil, and severs the fibres beneath it, the great association tract joining the temporal and frontal lobes with one another. Sixth, the mind may not recognize the use, odor, color, taste, etc., of any object presented to it. This general symptom is termed “apraxia.” It has, of necessity, as many varieties as there are avenues by which the mind may be reached; 416 for instance, by sight, smell, taste, hearing (not only hearing for language, but also for music), either of which may be lost separately, thus producing “ mind blindness,” “mind deafness,” etc. The patient, however, though unable to recognize any object when seen, may be able to do so when felt. These symptoms (according to Starr) are found only when the lesion is in the left hemisphere in a right-handed person, and in the right hemisphere in a left-handed person. Hence, in examining an aphasic thoroughly, Starr states that it is necessary to test, first, the power to recall the spoken or written name of an object, seen, heard, handled, tasted, or smelled. Second, the power to understand speech, andalsomusic. Third, the power to understand printed or written words. Fourth, the power to speak voluntarily. Does he talk clearly? Does he mispronounce words or talk jargon? Fifth, the power to repeat words when dictated. Sixth, the power to read aloud. Does he understand what he reads? Seventh, the power to write voluntarily. Can he read what he has written? Highth, the power to write at dictation. Ninth, the power to copy. Tenth, the power to recognize the use of objects seen, felt, heard, tasted, or smelled. One illustration, and only one, so far.as I know, exists of the diagnosis of a lesion by the existence of “mind blindness,” and this was fol- lowed by a brilliant and successful treatment. This is recorded by Macewen, and is briefly quoted on page 425 of this article. When it is remembered that the second, the third, the fourth, and the sixth nerves, in their entirety, are solely intended for innervation and specializing function of the organ of vision, it will be readily understood how im- portant this apparatus becomes as an index of intra- cranial disturbance. The methods may be briefly given in a series of short captions, as follows: 1. Always, if possible, get central vision in each eye separately, not only for form but for color, as this prac- tically gives the physiological power of the most highly evolutionized fibres of each retina. To do this, cards of known sizes of types or symbols, and graded areas of definite colors, such as green, red, rose, blue, and yellow, should be placed at certain distances in good light, and the results compared with the normal standards for such distances. Should the patient be unable to designate types, symbols, or colors, then keys, coins, etc., of the same size as certain test letters can be held at the related distances, or less if necessary, and attempts made for similar selection among duplicates held in the lap. 2. Power and range of accommodation should be tried separately and combinedly for the smallest type visible, with or without helping lenses, at the nearest, furthest, and best points possible. Retinoscopy may be useful in quite a number of cases. Tonic and clonic spasm must be sought for. 3. Visual fields must be most carefully studied in ref- erence to comparative sizes and areas for white, yellow, blue, red, and green; blind spots and points of feeble color saturation must also be diligently sought for and noted. 4. More complete study of central color perception should now be made with graded intensities of Holm- gren’s wools, and the results should be recorded upon suitable blanks. 5. The pupils should be examined and re-examined separately and in associated action, until definite an- - swers can be given as to their comparative sizes and shapes. 6. Careful attention must be paid to monocular and binocular action of the trides to light stimulus thrown from all parts of the visual field; to associated action with the ciliary muscles, as in accommodative efforts; and to the combined and associated action with the ciliary muscles and internal recti muscles, as in convergence, and these tests must be repeated over and over until un- equivocal results are obtained. Spasmodic action of the irides must be carefully looked for. 7. Hxtra-ocular muscle balance, when the organs are in a state of rest, should be obtained as correctly as possible. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, 8. Combined and disassociated action of the attached extra-ocular muscles in convergence, conjugate deviation, extreme separate and combined excursions in all direc- tions, must be gone over with special study of the vary- ing degrees of change from the slightest loss of innerva- tion up to total paralysis. Search for clonic and tonic spasms should also be carefully made. 9. Combined and associated action of the muscular ap- paratus of the ocular appendages should now follow, in reference both to paretic and to spasmodic changes. 10. Sensibility of the entire ocular superficies, both to touch and pain, should be studied. 11. In cases in which a difference of temperatures is suspected, comparative surface thermometry should be made, although it is really best not to omit it in any in- stance. 12. Accurate ophthalmoscopic study of the media and the fundus of each eye should be repeatedly made, until adequate dataas to the comparative condition of the two organs are correctly obtained. Having thus obtained this grouping of ocular condi- tions in association with the history and concomitant symptoms, determinations can often be made of sufficient accuracy to point out at least not only the probable character of the lesion, but even its possible situation. Negative signs may oftentimes prove themselves of great value in the diagnosis of the position of the supposed growth; and no case can be said to be complete and ready for surgical procedure until all the ocular changes have been properly and carefully studied. For the purposes of help in differential diagnosis the few following general observations may be of use: Optic neuritis is very usual in some stage of intra- cranial tumor, and indicates more rapid progress of the growth. It is of no definite value in the diagnosis of the position, the character, and the size of the mass. If the so-called monocular type be met with in such cases, the neoplasm is most probably situated in the op- posite hemisphere; and should the neuritis be double (which is most probably always the case), it is almost cer- tain that the side of the lesser optic nerve swelling is the one in which to look for the growth. The occurrence of this symptom is less frequent in abscess, and may be more ordinarily found upon the same side as that of the lesion than in tumor. It seldom occurs, if at all, in cor- tical lesions with irritative symptoms. Primary optic-nerve atrophy with or without retinal change, as shown by the ophthalmoscope, is generally found in connection with basilar disease or trunkal in- flammation, from trauma, new growths, general dys- crasia, and the introduction of toxic agents into the sys- tem. In epilepsy it is seldom decidedly marked, being usually found in its incipient form, and seemingly de- pendent upon the number and severity of the seizures. It is not apt to occur in abscess, except in those rare cases of the encysted and slowly growing varieties. Weakening of any single muscle or any group of muscles generally indicates either pressure from a coarse lesion, external to any portion of the related outgoing fibres, or true infiltration of pathogenic material into the neural meshes themselves. Unassociated with other symptoms it is of little value in questions of the position of the lesion, and must be used in conjunction with other data to be of any determining use. Being, how- ever, more of a fixed quantity than muscle irritation, it is of greater importance in such instances than the latter, as it better shows the probable position of the lesion. Localized spasm in itself is probably more apt to be caused by lesions in the motor zones and in the centres devoted to the action of the involved group or groups of muscles. It thus often offers itself of special diag- nostic value in the localization of the initial point of the epileptic spasm. In acute and subacute meningitis, irritative symptoms of both motor and sensory varieties appear, whereas in the chronic form degenerative changes are more prone to occur. Hemianopsia is of paramount importance, more so Vou. II.—27 than aphasia and agraphia. Each variety, carefully considered in conjunction with ophthalmoscopic study, experiments with pupillary responses, and other motor and sensory disturbances, can hardly fail to serve as most important data for indicating the probable situa- tion of the lesion. It must be remembered, however, that each ocular symptom in itself is not etiologically self-answerable. Careful study must be made of all the conditions, so that, by the process of exclusion, adequate data can be obtained upon which to base answers as to the character, ne type, and the situation of the supposed intracranial esion. Surface Temperature of the Head.—Mills and Lloyd, in Pepper’s “System of Medicine,” vol. v., p. 1036, have given the record of four cases of tumor of the cerebrum and one of the cerebellum. Seguin and Weir (loc. cit.) have recorded the temperatures in their case, and I have done the same in the case of tumor in my first paper al- ready referred to. The general conclusion seems to be that the average temperature of the whole head is ele- vated somewhat above the normal, and that the elevation of temperature is usually greatest at the station nearest to the site of the growth. But a much larger number of observations must be made in order to reach a definite conclusion as to this symptom; therefore, every case of supposed tumor, and, in fact, every other lesion in the skull, should have the surface temperatures carefully noted both before and after the operation, if any be done. In the second case in my paper the temperature certainly seemed to be elevated by the irritation of the lesion pres- ent. The elevation immediately disappeared after the operation, coincidently with the cessation of the epileptic attacks. In the third case in which the fits were relieved, but not cured, the temperature did not fall. Our sur- face thermometers also are as yet much lacking in ac- curacy, as they are used in practice. Diagnosis.—While in many cases the diagnosis is suf- ficiently clear, in others we are, of necessity, in the greatest doubt, until the operation, it may be, reveals the correctness or the incorrectness of our conclusions. Hence, as already quoted with approval from von Berg- mann, the great necessity of a correct diagnosis on the part of the neurologist, so that the surgeon may be sure that his attempt to remove a supposed tumor will not cause chagrin to both by finding none. This has oc- curred in numerous instances. In the careful and elaborate paper of Seguin and Weir, already referred to, it is pointed out that the diagnosis before operation must be worked out in five lines of in- quiry. (1) The existence of tumor; (2) its exact loca- tion; (3) whether it is cortical or subcortical; (4) whether solitary or multiple; (5) its nature; to which I would add (6) if possible, its size. 1. Diagnosis of the Existence of a Tuwmor.—When the symptoms referred to by Dr. Jacobi, in her article, are present—such, é.g., as headache, cerebral vomiting, grad- ually developing stupor, convulsions either general or lo- calized, paralysis in varying degrees, choked disc, some- times hemianopsia, slow pulse, probable localized rise of temperature with aphasia and apraxia, and in some cases with but little anzesthesia—it is almost certain that .we have a tumor to deal with. The most difficult diag- nosis is often between tumor and abscess, and for their differential diagnosis I must refer the reader to the article on Brain: Abscess of, on p. 218. 2. Diagnosis of the Location of the Tumor.—This must be done chiefly by the localizing symptoms. In certain parts of the brain a tumor may exist and give rise to no localizing symptoms, but only to general headache, choked disc, convulsions, etc. This is more particularly in the anterior portion of the frontal lobes,’in the tem- poro-sphenoidal lobes, especially on the right side, and in parts of the parietal and occipital lobes. But gradu- ally these “latent zones” are being narrowed progres- sively to smaller and smaller portions of the cerebrum. It is not too much to hope that eventually there may be no “latent zones.” The reader must refer to that portion 417 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. of this article which treats of Topography of the Brain, and to Dr. Jacobi’s and Dr. Starr’s papers in the pres- ent volume, for the details of the methods of localization, whether in the motor or in the sensory zones. One point must be regarded in following the history of a case. If a tumor increase in size, centres adjacent to the first. one involved will also be affected; hence a succession of addi- tional spasms and of pareses will develop in different parts of the body, and they are very important to study. The first limited spasm or paresis Seguin has proposed to call the “signal symptom ”—a happy name for an im- portant symptom in diagnosis. Rapidly produced blind- ness, as pointed out by Zenner and others, is usually due to tumors (especially in the cerebellum) which obstruct the veins of Galen or the straight sinus, and so produce internal (ventricular) hydrocephalus and pressure on the optic tracts, followed by choked disc and hemorrhages. 3. The Diagnosis of the Depth at which a Tumor Lies, 7.e., whether Cortical or Subcortical.—Seguin, in the article already quoted, concludes that a tumor of the cortex cannot be distinguished from a subcortical tumor by the character of the convulsions, or by the: presence or ab- sence of localized headache, or by the cranial tempera- ture. But tenderness on percussion rather than on press- ure may very possibly be of some service. In this as in the question of local temperatures, it must be urged that more exact and detailed clinical histories may hereafter give us the means of making such a diagnosis. How near one may come to removing a tumor and yet miss it, is well shown in a case of Sands, in which he recognized unusual resistance in two punctures by the needle, yet did not remove the growth, which was found at the autopsy just below the surface. Surgery had not then reached its present boldness and success. 4. Is the Tumor Solitary or Multiple ?—If solitary it may be successfully attacked by operation, but if multi- ple such an attempt would be clearly inadvisable in most cases, unless the multiple tumors are grouped within a limited area. If the tumor is single, the localizing symp- toms will probably point to one area alone, if the tumor be small; or if large, several areas may be involved, but these areas will be adjacent to the primary one. If, how- ever, localizing symptoms give two or more centres, far apart, without any intervening centres being involved, then the multiplicity of the growth is probable. 5. The Diagnosis of the Nature of the Tumor.—In some cases this may be made with fair approach to accuracy. For example, if the patient has cancer, tuberculosis, or syphilis in other organs, and shows characteristic symp- toms of intracranial tumor, it will most likely be of the same type as the disease in the other part of the body. Beyond these three classes of tumor I do not think it possible to make other than a guess at its nature. Hale White and von Bergmann are both opposed to operation in case the nature of the tumor is probably syphilitic. I quite agree with Seguin, however, that, provided thorough antisyphilitic treatment has been in- effectual, including the American method of the admin- istration of large and increasing doses of iodides, if pos- sible up to half an ounce a day, the probable gummatous character of the tumor or a syphilitic disease of the bones or membranes is not a bar to operation. gumma has become organized and permanently devel- oped, and has resisted vigorous specific treatment for six weeks, it should be attacked precisely as any other tumor would be dealt with, surgically, unless contraindicated by special symptoms, such as multiplicity, etc. 6. The Size of the Tumor.—This in a few cases can be probably diagnosticated. The diagnosis of a small tumor will be based upon its involving a restricted area of rep- resentation in the brain, as shown by the limited por- tion of the body involved; by the non-progressive in- volvement of neighboring centres; and by the absence of marked pressure symptoms. A large tumor will in- volve a large number of neighboring centres and would show marked pressure symptoms. Until the parts are exposed by operation, however, it is impossible to make any accurate diagnosis of the size of atumor. Itis prob- 418 Once a: able, however, that a few of them will be so large as to prohibit surgical interference, before the general symp- toms will be so grave as to make such interference quite inadvisable. Surgical Treatment of Intracranial Tumors.—I have already referred to the historical case of Bennett and Godlee, which was the first really to arouse the attention of the surgical world to the possible diagnostication and removal of a brain tumor, of which there were no ex- ternal local symptoms. I have also referred to some later cases which have been operated upon. The num- _ber of intracranial tumors operated upon has now reached such proportions (vide infra) that we can assume it as conceded that in all suitable cases operation should be at least attempted. As to operative technique I have already considered the various steps under that head. The only point neces- sary to be’ insisted upon here is, that in cases of tumor which are not encapsulated, it is important that not only the entire tumor shall be removed, but also the zone of apparently healthy but probably infiltrated brain tissue in its immediate vicinity, so that we may be sure, so far as it is possible, that we have removed the entire neo- plasm. In doing so the surgeon must remember that he can excise with greater impunity a larger area in the antero-posterior direction than in the vertical, for reasons already given. Prognosis.—lf the tumor is malignant, its return is only a question of time in the majority of cases. In tubercu- lous and syphilitic tumors the prognosis is, of course, a a much more favorable one; while in cases of benign growths, such as fibroma, recurrence is not to be ex- pected. The prognosis as to death or recovery from such opera- tion cannot be made in any individual case, for up to the time of the operation we cannot be certain of the size and the relations of such tumor, nor of the surgical complications that may arise during its removal. The percentage of recoveries in cases of operation on in- tracranial tumors has been, for a new operation, unex- pectedly large. Of course, in any individual case, it will depend largely on the size, position, complications, ete. When the first edition of the REFERENCE HANDBOOK was published, I could gather only 17 cases of tumor which had been operated on, of which 8 were in the cere- bellum and all 3 died. In 1898 von Bergmann published the most recent sta- tistics, which cover 273 operations for intracranial tumors. of all kinds, of which 169 (61.9 per cent.) recovered and 104 (38.1 per cent.) died. One hundred and fifty-seven were exploratory or palliative operations, of which 82 (538.5 per cent.) recovered and 75 (46.5 per cent.) died. The chief reason for the fatality in exploratory or pallia- tive operations has been either too extensive exploration in search of the tumor or for its removal, or that many of the cases were inoperable from the size or location of the growth and only relief from intracranial pressure was sought. If no tumor is found after cautious search by the knife, grooved director, and the gentlest use of the lit- tle finger, or if, being found, it is not removable, the op- eration should be terminated at once, especially if there is much bulging, indicating a large tumor. In fact, in cases of great increase in the intracranial pressure, until I have determined the fact that the tumor can be removed, Iam very cautious about making a large opening in the dura, since the pressure will force out a large amount of brain substance which cannot possibly be replaced with- out extensive laceration, which invites fungus cerebri. Of fourteen cases in which trephining was done for the relief of increased intracranial pressure, all recovered. Another important cause for the high mortality of the whole series has been the delay in operating. Physicians, who almost always see these cases first, postpone con- sulting the surgeon for an unreasonably long time in the vain hope of improvement. It cannot be too strongly insisted upon that tumors of the brain should be treated precisely like tumors in other parts of the body, by re- moval at the earliest practicable moment. In fact, in REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, the brain the reasons for early operation are even more cogent than elsewhere: its soft tissues are more easily injured; it cannot escape from pressure as do the soft parts, since the bony case in which it lies prevents this; and the growth of the tumor within the skull is insidi- ous and not easily perceived, as it is when accessible to touch and sight. Progressive growth can be inferred only from progressive symptoms. As soon, therefore, as drugs have had a fair trial an operation should imme- diately be done, if the tumor can be located with reason- able certainty and if there is a fair prospect of success by operation. The limit of the “fair trial” Horsley places, and I think rightly, at six weeks. After that, time is wasted and life imperilled by longer waiting, since time only allows of increase in the size of the tumor with wider infiltration of brain tissue and the wider destruc- . tion by pressure, and the operative difficulties and dangers rapidly increase with each week or month of delay. In the case of irremovable tumors, the opening in the skull should not be closed by replacing the bone. This partial operation will often be an immense comfort, and Ihave had the same experience that Horsley has had —namely, that the patient found so much relief from one operation that he requested a second. Operations upon cerebellar tumors—by reason of their proximity to the fourth ventricle, the tubercula quadri- gemina, and the pons with their important and vital cen- tres—are more hazardous than those performed in any other less vital regions of the brain. Out of 23 cases, 15 died. Epiteprsy.—From a surgical point of view cases of epilepsy may be sharply divided into the traumatic and the non-traumatic varieties. The cases arising from traumatism can again be subdivided into (1) those in which the scar, old depression, etc., arising from injury, lies over well-recognized centres, motor or otherwise, and (2) those in which the evidences of injury lie over the so-called “latent zones” in the brain. In those cases in which the lesion lies over well-known centres, and the epileptic fits affect only the muscles corresponding to the motor centres (monospasm or hemi- spasm), there can be no question at present as to the pro- priety of surgical interference, and the excision of the epileptogenous centre so involved. In cases in which the injury lies over a portion of the “latent zones,” I believe that here also it is often proper to operate. It is true, time has cooled our earliest enthusiasm, but epilepsy is such a terrible disease that I find most parents are of my own opinion, viz., that no risk, even of death, still less of the probability of failure, is to be weighed against the possibility of benefit orcure. The danger of death is not very great, the number of failures is large, the number of cases benefited is considerable, the num- ber of cures is limited but encouraging. If we could operate early, before the “epileptic habit” is formed, the number of cures would be much greater. In these traumatic cases it is always possible that the scalp may be the site of irritation, and should there at least be no evidence of depression of the skull, it would always be wise, therefore, to excise the scar first of all, especially if it be tender, or if pressure upon it produces pain or an epileptic fit, or if the epileptic aura starts from the scar. Even should none of these symptoms be present, and if the bone be not fractured, I should deem. it right first to excise the scar and then to wait in order to see whether this would cut short the epileptic seizures. Thus Briggs reports five such cases and Mears one in which such a happy result followed mere excision of the scars. I also have had two cases in which the attacks have not returned for several years after merely ex- cising the scar. In one case the immunity has reached nine years. Any other source of peripheral irritation must also be eliminated, as has long since been ob- served. Briggsrelates a case in point in the same paper, in which a girl had both a depressed cranial fracture and necrosis of the tibia. He wisely operated on the tibia first to eliminate this as a source of irritation, and the fits had not recurred when the case was reported five years later, thus disproving their origin from the fracture of the skull, which was prima facie the most probable cause. It must be remembered also that any operation is apt to cause a cessation of the fits for some time; hence, before deciding that the epilepsy has been cured by removal of the scar or other source of irritation, at least two or three years of immunity should elapse. Should excision of the scar not cure the patient, or should there be a depression of the skull, with fits cor- responding in their distribution to the motor centre or centres over which the scar lies, the patient should be trephined. The operator may find a splintering of the inner table. Sometimes a cyst will have been developed under the site of the injury. Sometimes, as a result of laceration of the brain tissue at the time of the injury, a brain scar will be found. The dura also wili have been ruptured in some cases, and a scar will be found in it; or mere eburnation of the bones, as a result of osteitis from the traumatism, may be the only lesion. The skull hav- ing been trephined and the dura opened, the damaged brain tissue should be removed; and if there be a scar or thickening of the dura, the dura itself should be removed. In removing the damaged brain tissue, care must be taken to see that it is a// removed, even to the extent of trenching upon apparently healthy brain tissue, and the directions heretofore given that freer excision may be made in the antero-posterior direction than in the vertical (for reasons already mentioned) must be remembered. The bone should not be replaced in a large piece, if by its shape, or for any other reason, it would cause press- ure on the brain. [t may sometimes be replaced to ad- vantage after dividing it into small pieces by the chisel or rongeur forceps. In those cases in which the lesion lies over the “latent zones,” the same rule as that given above would apply to the excision of the cutaneous scar. Should this not effect a cure, then it would be proper to operate. What should be done would depend upon what was found to exist in the brain, and any damaged brain tissue or cyst should be excised as already advised. Occasionally, after accidents, primary trephining will have been done, yet epilepsy will develop at a longer or shorter time after healing. In such cases, no matter where the scar is situated, it is some- times wise to raise the flap over the site of the primary trephining and round off the edges of the bone, and to ex- cise any scar in the dura or in the brain which may have resulted from the primary traumatism, or from any operation done at that time. Occasionally some benefit will follow, but generally the result will only be a tem- porary cessation of the attacks. Non-Traumatic Epilepsy.—First, of the Jacksonian type. So far as our limited experience goes, it seems probable that in cases of distinct Jacksonian epilepsy it is proper to operate, and to excise the centre correspond- ing to that portion of the body which is involved. The experience of Horsley and Macewen, as well as quite a number of other operators, at present would seem to show that such operations at least do no harm, and in not a few cases they have resulted in apparent recovery both from the epilepsy and from the operation. It isa matter of some importance also that if we operate at all, it shall be as early as possible, before the “epileptic habit” has been established. But both in thisand in the non-Jacksonian type, 7 7s of the utmost importance that the fits shall have been always observed by a competent, and, if possible, w trained observer. Ihave had brought to me for operation a large number of cases of alleged Jack- sonian epilepsy, and others of ordinary epileptic type, in which the fits were said to be limited and uniform in the point of beginning. These statements have been in some cases the result of the patient’s knowledge, but. more commonly of that of members of the family only. It is very evident that persons not trained to exact ob- servation, and especially those persons whose affections are involved, and whose first motive would be to aid the: patient rather than to observe the fit, are, as a rule, in- competent observers. Frequently, after placing such persons under observation in hospital, I have found that 419 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. the fits had not been at all correctly described. There- fore it cannot be too strongly insisted upon that accurate observations shall be made the foundation of knowledge before we proceed to excise any brain centre. In mak- ing these observations, not only should the observer note all the phenomena in detail, and especially the muscles in- volved—particularly the muscle or muscles first involved (Seguin’s “signal symptom”)—and the “march” of the fit (that is, the progressive involvement of one muscle or set of muscles after another), but the dynamometer should be used as soon as possible after the fit to deter- mine whether the muscles involved in the fit be paretic. Such operations have been seriously objected to on the ground of subsequent paralysis. This seems to me not to be a valid objection. To exchange epilepsy for paralysis would, I think, be a choice at which few pa- tients would hesitate. It must also be remembered that the excision of a centre for an ordinary group of mus- cles, though it be followed by paralysis which may even be complete, has resulted eventually in so great a restora- tion of power as to convert the paralysisinto only moder- ate paresis, probably through the compensative action of the centre on the opposite side. Thus, in the third case related in my first paper already referred to, in which excision of the wrist centre was done, the patient was entirely paralyzed from May 30, 1888, till early in July. Motion began to return at this time, and when I last saw him, in the middle of September, 1888, he had so far re- gained control of his hand as to be able to play baseball. The fits, however, had persisted, though changed in type, there being now but few severe convulsions, and only a moderate number of attacks of petit mal. In an- other case in which I excised the thumb centre the hand and arm became paralyzed to the elbow. This rapidly disappeared, and in a few weeks the patient could again sew perfectly well and the dynamometer showed no dif- ference in the muscular power of the two thumbs. As to operative procedure in these cases, it is impor- tant, first of all, to obtain a view of the brain sufficiently large for the operator to be able to recognize the con- volutions. Once the convolutions are exposed, no anti- septic solution should be allowed to touch them until the centre sought for shall have been well defined by the battery. Hot water, however, may be used to check the bleeding. As soon as the brain is uncovered the faradic current should be employed by means of my double electrode (Fig. 10238, page 409). The remainder of the operative procedure is as de- scribed in the section on the technique. Secondly, in cases of general or “essential” epilepsy experience has shown that it is better to refrain from operation as a rule. INJURIES OF THE HEAD.—Contusion.—In any case of serious contusion, the patient should at once be put to bed on light diet, and the bowels and general hygiene carefully looked to. The patient should then be closely watched, and, if any serious symptoms arise indicating intracranial mischief, a semicircular flap of the scalp should be raised and the bone inspected. If a fracture of the bone be discovered and the symptoms are at all serious, showing that inflammation of the meninges or of the brain substance has set in, or is impending, ex- ploratory trephining must be done at once, and the dura be opened. Even if no fracture exists, if the symptoms are those of encephalitis, trephining should be done. It is possible, in such a case, either that a piece of the inner table has been separated, with or without external frac- ture, or that the dura has been ruptured or the brain Jacerated, and that inflammation with exudation has be- gun. Once inflammation with its attending proliferation has set in, it is essential that a means of escape for the exudate be provided for, or for the escape of pus if the inflammation shall have proceeded so far. In other words, we should treat contusions followed by serious symptoms of mischief in precisely the same manner that we would treat them in any other part of the body, al- ways remembering that in the brain it is impossible for any exudate or hemorrhage to find its way to the sur- 420 face without surgical assistance, by reason of the bony case in which it is retained. Trephining of the skull, therefore, is equivalent only to incision through the soft parts down to the seat of injury in any other part of the body. In many cases of very severe contusion, it would be proper immediately to make a horsehoe flap in order to determine the question of fracture. The swelling of the scalp is often so thick and so dense that in some cases it is extremely difficult to ascertain whether a frac- ture exists or not without such an incision. It is all-im- portant to know this fact, and especially if there be de- pression or not, so that the proper treatment shall be adopted. Preventive trephining, in many of these cases, is not only justifiable but demanded. A simple incision through the scalp is of itself unattended with danger in these days of antiseptic surgery. It may be objected that if a simple fracture exists, by such an incision we convert it into a compound one; but the position taken by Roberts in 1885 is certainly the correct one, that such an incision, with modern surgical methods, adds nothing to the danger, and is the only method by which we can make an absolutely certain diagnosis in any serious case, and so enable us to pursue a course of treatment which will diminish or avoid the danger. Should there be motor paralysis without any decided loss of sensation, there is almost certainly a lesion of the cortex; but, as Ferrier has pointed out, if sensation is impaired to any extent, there is probably a lesion of the sensory tracts of the internal capsule, or of the centres to which they are distributed. Even after recovery from a severe contusion of the head, the patient should be carefully watched for some months, as in not a few instances abscesses, cysts, or epilepsy has developed after a long time. One case in which I trephined, a month after an exploratory incision of the scalp alone had been made, was most instructive as to the intracranial effects of a very slight extracranial traumatism. Inenlarging the trephine opening, I found that the dura suddenly became remarkably adherent to the bone. Inspection showed me that the area of ad- hesion was precisely under the flap of the first operation. This had been simply the raising of a flap of scalp, had been conducted with the utmost antiseptic care, and had healed without incident in a few days; yet the simple lifting of this flap had been felt instantly within the cranium, and exhibited itself by the strong adhesion be- tween the dura and the bone. A severe contusion, therefore, it can easily be understood, even without fracture of the bone, might set up such inflammation as would ultimately lead to suppuration, to the formation of a cyst or a tumor, or to such organic changes as would be followed by epilepsy. Williams has reported an un- usual case in which a blow on the forehead produced an abscess which discharged through the nose. Compression of the Brain.—In 1885, in a paper read before the American Surgical Association, Roberts in- sisted that the complexus of symptoms passing under the title of “compression of the brain” was due not so much to compression as to brain laceration and inflam- mation. In cases of encephalic hemorrhage, we cer- tainly have an example of compression. Apart from this cause, and probably from tumor and from effusion, in both of which, however, inflammation has a large share, I certainly would agree with the position taken by him. A blow which is followed by symptoms of compression, when it is sufficiently serious to produce violence to the membranes, or laceration of the brain tissues, is, as a rule, one which has been followed by in- flammation; and it is this inflammation with its exudate and swelling that causes the mischief. We are apt to think of increased intracranial pressure as a result to be looked for only from tumor, abscess, or effusion into the ventricles. But it is certainly reasonable to believe that mere inflammation of the cranial contents will be at- tended by swelling as in other tissues, and that thereby the intracranial pressure will be increased. An experiment by Felizet is full of instruction. He filled a skull with melted paraffin, and after this had REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain. cooled, he let the skull fall from a moderate height to the floor. The calvarium was then removed. No fracture existed, but the surface of the paraffin was flattened at the point corresponding to the blow. The skull had been momentarily depressed, and had returned again to its former shape by its elastic resiliency. Undoubtedly the same occurs in the brain, and no such momentary changes of form from violence, even though followed by a restoration of the organ to its original place, can have been produced without more or less laceration of the brain tissue. What is to be feared is that inflammation will take place, and that the products of inflammation will produce symptoms of pressure. Hence, in such cases, I would trephine for the same reasons as are given under the last heading, if similar symptoms arise. Scalp. Wounds and Injuries of the Head.—In every case of scalp wound, the head should be shaved over a large area, and scrubbed with a nail brushand soap and water, followed by an application of ether, and then of a sub- limate solution. The scalp should, of course, by this process be thoroughly cleansed from all dirt and foreign substances, and if need be the edges of the wound should be trimmed in order entirely to get rid of the dust and dirt. The wound may now, and not until now, be ex- amined by a probe and the finger, both of which must be entirely aseptic. Should the injury be limited to the scalp and the periosteum, after providing for drainage, the wound should be closed and dressed antiseptically. But should the skull be fractured, it should be treated as described below. In wounds which produce a crushing or sloughing of the scalp, the late Dr. William Hunt called my attention to the fact that the depressed scar result- ing from loss of scalp tissue only, not seldom may be mis- taken for an old depressed fracture of the skull—an error he had known to be made by more than one good surgeon. Simple Fracture of the Skull without Depression.—This is often exceedingly difficult to diagnosticate. One of my patients, a bright, intelligent fellow, experimented on his own head the morning after a fall of nine feet, by tapping on his head on the injured side. He elicited a “cracked-pot” sound which did not exist on the unin- jured side. It is possible that this may be sometimes of great value in diagnosticating simple fracture without depression. If the fracture be simple and without de- pression, and without cerebral symptoms, it should be treated expectantly, but the moment that there are any symptoms of encephalitis the trephine should be used for the reasons previously stated. Two most instructive cases of such trephining are reported by Heusner. Simple Fracture with Depression.—In simple fracture with depression I should certainly advise immediate preventive trephining, even if there be no sign of en- cephalic mischief present, although I am quite aware that many conservative surgeons are opposed to such radical treatment. As already stated, the conversion of a simple fracture into a compound one is at present at- tended with no serious risk. It must be remembered that any violence sufficient to break a bone and to de- press it will unquestionably have produced some lacera- tion of the brain substance, and possibly of the dura. In addition to this, as the inner table is so much more easily fractured than the outer, occasionally a fragment may have been detached and driven into the brain. The immediate dangers arising from such a fragment of bone and laceration of the cerebral tissues and membranes are _ those of serious inflammation, and if the products of in- flammation are confined within the skull, without possi- bility of escape by drainage, the danger is a serious one. Even should the patient recover, as is undoubtedly often the case, the numerous instances of epilepsy arising from irritation of a scar, from a cyst, or from secondary de- generation are so great, and the danger of trephining so small, that but little choice would seem to exist. Compound Fractures of the Skull.—The rule in such cases should be always to explore by a large incision in the scalp. Should there be no depression, no strong probability of separation of the inner table, or of serious laceration of the brain, or of hemorrhage, the wound ‘should be most scrupulously disinfected, and, after careful antiseptic dressing, the expectant plan should be pursued. Should the fracture bea mere linear fissure, after careful disinfection, if the fissure be at all impregnated with hair, dirt, etc., the soiled edges should be carefully chiselledk away so as to make sure that we have cleaned them of all infective material; for it is in the probable infection more than in the mere fissured fracture (apart from the violence of the accident) that the danger of encephalic mischief lies. In doing this only the outer table need be cut away. An antiseptic dressing should then be applied. But if depression exists, and there are symptoms which lead us to believe that serious injury to the brain, or fracture of the inner table, or hemorrhage is present, preventive trephining should be done at once. It goes without saying that a large area of the scalp should be shaved and most rigidly disinfected in all these cases. Mr. Mayo Robson has reported an excellent illustra- tion of the value of comparatively early trephining in such cases. A man received a blow on the left side of the head directly over the arm centre, the scalp showing a small lacerated wound. The right arm was paralyzed, this condition being attributed by the surgeon who first saw him only to bruising. Later rhythmic epileptiform spasms began in this hand, followed by facial paresis, cedema of the left optic disc, and exaggerated reflexes on the right side. Exploration showed a depressed frac- ture, and trephining saved his life. The twitchings dis- appeared in six days after the operation. Even had he recovered without operation he would probably have suffered from a Jacksonian epilepsy. Ina case of extensive compound fracture of the oc- ciput, so early as 1810, Hutchison boldly anticipated modern surgery with the happiest results. The patient had fallen thirty feet and fractured the occiput, the frac- ture extending into the foramen magnum, as proved at the operation. He was trephined at once, and, to the embarrassment of the surgeon, the dura bulged beyond the outer surface of the bone, and by its elasticity showed that there was an extravasation of blood beneathit. The next day this was incised, the blood evacuated, and, after a tedious illness from a suppuration that would now hap- pily be conspicuous by its absence, the patient recovered. In Punctured Wounds of the Brain, which are of course always compound fractures of the most dangerous char- acter, the rule should be adsolute to trephine at once, whether there be brain symptoms or not. The almost certain danger of septic inflammation, and the need both for immediate provision for drainage and for antiseptic cleansing of the wound, render immediate trephining imperative, just as incision, cleansing, and drainage of a similar wound in the soft tissues isthe rule. No better illustration could be given than that of a case reported by Ball in which a man was struck on the left temple with a pen-knife. The wound was not considered serious enough to warrant ‘his admission to the hospital where he first applied. Ten days later aphasia, word blindness, and word deafness set in, without paralysis. Five days later he was trephined. The knife blade had penetrated the dura and wounded the brain. memory, imbecility. ENE stupor. Cases. Per cent./Cases. Per cent.|Cases. Per cent.|Cases. Percent./Cases. Percent.||Cases. Percent. Medulla, 29 cases.........se08. 6 20 2 ii 2 i 1 3.0 11 38 18 62 Cerebellum, 162 cases .......... 48 29 1 . 6 3 9 5 64 39 98 60 DTEOR OT CASES vec cccs cee necice Ss aie ate re 66, ewe a aehte 28 49 ve wate PONS, 56 CASES 0... ccseeee 48 i : s 1 bias 29 51.5 27 48.5 Basal ganglia, 40 cases . 45 1 oF 2 sats ae ASAE 21 52 19 47 Lobes, 192 cases........ 46.5 9 4 11 5.5 5 2.5 115 60 77 40 OCC IDA Es . aru y aici ofere aie Sdcic er ae oe GAC ac Darcie ae: ahah i Sev ROTA ete ra/e ties ees sie 10% a i eect: 6 10 11 19 AMICUS eC cciieniccees sels s 15.5 i 2 re 7 12 19 33 17 29.5 SEPIO IATA cece ccapccs vase ress 3 ae 56 Rate ne Git ie ocr Corpora quadrigemina, 13 cases} 4 30 2 15 4 30 10 77 3 23 ways the excitation of a vomiting centre in the medulla; and this can be brought about by pressure transmitted from any part of the brain. This pressure is, however, more direct when exercised from some point in the pos- terior cranial fossa; hence a second reason for the in- tensity of the symptom in cases of tumor of this locality. The vomiting is unattended by nausea and occurs on an empty stomach and with a clean tongue, and in these respects contrasts markedly with the vomiting of uremia. It is apt to follow the headache closely, and, as in mi- graine, to occur at the height of the paroxysm of pain, and also in the early morning. Epileptiform Convulsions constitute a fourth diffused symptom, which is very characteristic of tumors of the brain. Their causal relations to increased intracranial pressure have been strikingly shown by Leyden’s experi- ments. In these, pressure was directly applied to the brain of animals previously trepanned for the purpose. Convulsions occurred as soon as the pressure had risen to 180 mm. of mercury. Pressure, however, is only one of the mechanisms by which convulsions may be excited. Kussmaul’s experiments, made many years ago, showed that sudden anzemia of the brain, such as might be in- duced by copious hemorrhage, was invariably followed by convulsions. The predominance of convulsions in cases of brain tumor, according to the locality occupied by the latter, does not follow the law which is applicable to symptoms traceable to increased pressure, for convul- sions occur oftenest in cases of tumor of the cortex and cerebral lobes, presumably of the portions of the centrum ovale which lie immediately beneath the cortex. General convulsions, therefore, like local spasms, are rendered imminent by direct excitation of the motor tracts. Curi- ously enough, convulsions are almost excluded from the symptomatology of the pons, though this region, which is traversed in every direction by motor tracts, probably contains the convulsing centre. But apparently the properties of the centre become abolished before they can be effectually irritated. This absence of convulsions, when certain positive signs are present at the same time, is of real value in localizing a tumor in the pons. As the convulsion is not proportioned to the locality of greatest tension, so it stands in no relation to the time at which tension is greatest. It occurs as an initial symptom, or during the active period of the disease; but it usually disappears, with other irritative symptoms, in some other manner toward the close, when intracranial pressure is at its maximum. Sudden variations in such pressure, caused by fluctuations of the circulation, seem to be the essential proximate cause of the convulsions of brain tumors. The form of the convulsion does not differ from that observed in idiopathic epilepsy, and the diagnosis between tumor and epilepsy is often difficult. It can be made only by means of the concomitant symptoms. Convulsions occurring in adult life for the first time should at once excite suspicion of brain tumor and lead to an ophthalmoscopic examination for choked disc. According to Bruns, convulsions may occasionally precede for years, and with intermittences of years, all other symptoms of an intracranial growth. Apoplectiform Attacks occur with brain tumors, and may, though rarely, be the first symptom, and followed by paralysis or paresis. It is extremely difficult, then, to distinguish the case from one of ordinary cerebral hemorrhage. Hemorrhage into or around the tumor is a frequent cause of apoplexy, and thus may first reveal the existence of a tumor hitherto latent; or it may occur in- cidentally among phenomena already well defined and recognized. Finally, the apoplectic attack may usher in the terminal period; the patient never completely recovering, but passing into a soporose condition and finally into coma. The apoplectic ictus is not invariably associated with hemorrhage; it may be due to sudden alterations of intracranial pressure, by which the func- tions of brain tissue are temporarily suspended, as after concussion. Psychic Changes.—The earliest is usually an extreme irritability, which contrasts with the lachrymose emo- tionality characteristic of softening of the brain. Occa- sionally this culminates in attacks of maniacal excite- ment; oftener, however, the patient suffers from mel- ancholic depression, and gradually becomes more and more apathetic and taciturn. This taciturnity, which is a diffused symptom, must be distinguished from true aphasia. As in all mental disturbances, the memory fails. Dementia may precede death for some time, es- pecially if epileptic convulsions have been severe. The specific psychic symptom of brain tumor is drowsiness, from which it is often difficult to rouse the patient. When roused, however, his mind may seem unexpect- edly clear. The drowsiness is proportioned to the degree of general intracranial pressure. It is particularly marked in tumors of the frontal lobes, which may reach a considerable size without occasioning other symptoms. Table III. shows that the liability to psychic symp- toms other than drowsiness is not at its maximum when the tumor is seated at the cortex, nor when a cortical tumor is in the frontal lobes. Cortical tumors stand third from the bottom of the scale in this respect; the highest place is occupied by tumors of the corpora quadrigemina, seventy-seven per cent. A relative infre- quence of mental disturbances is observed in tumors of the medulla and pons. On the other hand, the high percentage of such disturbances in tumors of the centrum ovale may probably be, at least in part, attributed te . their influence upon the cortex. To such influence must, in last analysis, all psychic perversions be ascribed; and the high proportion of cases in which these are present with tumor in any locality of the brain is explained by the extreme sensitiveness of the cortical substance to dis- turbance of the intracranial pressure from whatever point diffused. Psychic symptoms, of one kind or another, are seen to be extremely frequent in tumors of the brain, being present in about half the cases. Their presence, therefore, materially aids in establishing the diagnosis. Certain specific psychoses, as paranoia and hysteria, are occasionally excited by the presence of a brain tumor. Choked Disc.—This symptom, when present, is more nearly pathognomonic than any other of brain tumor. According to Oppenheim, ninety per cent. of all cases of 437 Brain, Brain. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. choked disc are due to intracranial growths. The choked disc has been differently regarded as the expression of two different morbid processes: an inflammation of the optic nerve, “neuritis optica,” or a mechanical obstruc- tion to its circulation, which should be the choked disc proper. Oppenheim notes that in tumors of the base of the cranium, which are liable to obstruct the flow of lymph into the sheath of the optic nerve, the choked disc is usually lacking, and tumors of the optic nerve itself are apt to lead to direct atrophy of the nerve with- out any preliminary stage of choked disc. These facts are counted as an argument in support of the celebrated doctrine of von Graefe, who attributed the choked disc in all cases to an obstruction offered to the venous cir- culation of the optic nerve, from immediate or mediate pressure exercised upon the sinus cavernosus; hence a serous transudation from the veins, rendering the papilla swollen and edematous. As seen with the ophthalmo- scope the papilla appears engorged, tumefied, nebulous, irregular, and with ill-defined edges; a spirus of cloud covers both the centre and the circumference, rendering the whole surface opaque. The arteries are diminished in calibre, the veins appear interrupted at various points. papilla sometimes atrophies without passing through any stage of choked disc. Until atrophy sets in, vision is not necessarily impaired. Thus, out of a total of 82 cases of choked disc, vision remained intact in 37, or 45 per cent. In a great many cases no ophthalmoscopic examination is made, unless vision is impaired, and this explains why such examination is lacking to the history in 282 out of 485 observations analyzed by Bernhardt (47.8 per cent.). In many of these negative cases it is very possible that choked disc really existed, so that the real proportion of this lesion in brain tumor cannot be considered as known. 5 The ten per cent. of cases of choked disc which are not caused by intracranial growths have a very diverse etiol- ogy. Thecondition has been seen in pernicious anzemia ; in a few cases of arteriosclerosis, when the arteries of the optic nerve are involved; inabscess; in multiple sclerosis. In a certain number of cases cerebral tumor manifests itself exclusively by one or more of the foregoing “ dif- fuse” symptoms. Among Bernhardt’s cases of tumors of the cortex, centrum ovale, cerebellum, and basal gan- glia, this limitation may be found 71 times out of a total of 297 cases, or 23.8 per cent. TABLE IV.—CASES OF DIFFUSED SYMPTOMS ALONE. ' . . Lan | eS gl | ee aa Bee by Je 3 | 2H] oQ] coo l| gs ls else ssisss| » | gd | &9 q 85/82) 85 |See¢@n ae¢slagdala sn] g ) a5 S | 32/82 | 38 |S88/88 5/32 cls85| | 2 | Ss Seat. as S Sai we sae Sa SF bi cs Set 3 2 ‘2 | Psychic alteration. Total. $ | S85 | 88 | 83 |Sas|saaisaee(see| 51 & | x mo) Ry me | mS eRe Sim ER Smee > | So] Es = 5 = 5 I =) = FTE SS) iS) = CS) 3 Ss ° ° © Cortex, 57 CaS€S ......eeeeees 4 3 1 5: re 1 is 1 1 | In 7 of these......- 11 = 19 per cent. Lobes, 124 CaS@S «0.0. swceeses 5 3 8 2 4 5 3 2 4 1 | In 22 of these...... 37 = 29 per cent. Basal ganglia, 26 cases ...... 2 1 we ; oe Ae « 5 2 1 alone, 1 besides.. 6 = 23 per cent. Cerebellum, 90 cases ........ 2 6 1 3 At % 4 1 In 4 of these....... 17 = 18.5 per cent. TPOUAL . s ccclessrevelesis ore eens 13 13 10 2 7 6 7 2 8 2 35 71 = 23.8 per cent. In one form the capillaries are increased in size, in the other they are effaced. Bruns considers these two forms simply gradations of each other, the neuritis optica being the incipient stage, the choked disc proper the advanced stage of the same process. When the arteries have almost ceased to be distinguishable, except at the periphery of the retina, small hemorrhages usually form in the retina, and spots of fatty degeneration are seen, the latter being a serious threat of speedy blindness. Against the doctrine of venous obstruction as a cause of choked disc, it has been urged that the free inoscula- tion of the ophthalmic vein with the angular branch of the facial suffices to avert complete venous obstruction, even when the circulation in the cavernous sinus has been retarded. Further, a free communication has been de- monstrated between the intervaginal lymphatic space of the optic nerve and the subarachnoid space of the brain. It has been shown that a rise of intracranial pressure suffices to force cerebro-spinal fluid into the intervaginal space of the nerve, thus causing compression of its cen- tral vessels, local obstruction, and swelling from transu- dation, apart from venous obstructions. Choked disc sometimes appears in cases in which the tumor is so small that much increase of intracranial pressure seems doubtful. It is then more probably due to inflammation of the optic nerve, first propagated from irritated brain tissue to the central terminations of the nerve, neuritis from diffused cerebritis (Mackenzie), or excited by direct pressure upon the optic tract. Such direct pressure is exercised by tumors of the corpora quadrigemina, the chiasma, the cerebral peduncles, or the interpeduncular space. Choked disc is found far more frequently (54 per cent.) in cases in which the tumor involves the corpora quadri- gemina, than in those in which it involves any other part of the brain. The smallest percentage is in the class of cases in which the basal ganglia are the seat of the tu- mor. When there is direct pressure on the optic tract, the 438 The existence of mental symptoms in a large propor- tion of these cases (49 per cent. of them) is the circum- stance that might, perhaps, most surely guide in the diagnosis, otherwise so difficult. The proximate consequences of increased intracranial pressure, which are the immediate cause of the diffused symptoms, have been differently interpreted. It was long maintained that the brain substance was nearly as incompressible as water. Room, therefore, could be made within the cranium for a neoplasm only by propor- tionate expulsion of blood and lymph, and by atrophy of the brain tissues in the immediate vicinity of the tumor. Adamkiewicz’s experiments have shown, how- ever, that the nerve tissue surrounding the tumor is compressed, 7.e., its solid molecules are approximated, and the fluid normally interposed between them is, to a greater or less extent, expelled. For, when a piece of laminaria was inserted under the skull of an animal pre- viously trepanned for the purpose, and was allowed to swell, thus rapidly encroaching upon the intracranial space, microscopic examination of the tissue in which the foreign body was embedded revealed the fact that all the nerve elements of this tissue were closely crowded together, thus apparently multiplied in a given space. The zone adjacent to this was intensely vascularized from dilatation and new development of capillaries, and, in ad- dition, it was hypertrophied from proliferation of con- nective tissue. In the experiment, the swelling of the laminaria was much more‘rapid than is the growth of any tumor, and the condensation and nutritive irritation of tissue were therefore exaggerated. To a greater or less extent, however, both these lesions must always be produced by the presence of a foreign body within the cavity of the cranium... Only when the tumor grows very slowly are they absent, or reduced to sucha minimum as to occasion no symptoms, either diffused or focal. The elements of gliomatous tumors are the most liable to so insinuate themselves between the elements of the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, brain tissue as to avoid compression, and no well-defined line of demarcation separates the tumor from the brain mass. In this respect the sarcomata contrast markedly, and may be distinguished by the naked eye by the zone of softening which circumscribes them. Carcinomata and tubercle directly destroy brain tissue and take its place. The occurrence, in twenty-three per cent. of the cases, of diffused without focal symptoms indicates that the centres of origin of nerve tracts have remained un- affected, though the vomiting and convulsive centres and the nervous filaments of the dura mater have been irritated ;-that lymph has been forced into the sheath of the optic nerve, or that a descending neuritis has been excited by propagation from the zone of cerebritis sur- rounding the tumor; and that the delicate psychic mechanisms of the cerebral cortex have been irreparably jarred and are out of working order. This immunity of motor, sensory, or special-sense nerve functions is usually due to the localization of the tumor in a “latent” portion of the brain; but it is also sometimes observed in cases in which the tumor occupies a (presumable) focus of nerve origin. Thus, although there can be no doubt that the ultimate origin of the motor nerves contained in the pyramidal tracts is in the central gyri and paracentral lobule, tumors seated in these localities have sometimes been observed entirely unaccompanied by motor symptoms, either irritative or paralytic. Two such cases are contained among the eleven of the table. In one of these there were forty hydatid cysts in the brain, a form of neoplasm very fre- quently latent. In the second case, however, there was amost extensive sarcoma occupying the lower half of the anterior central gyrus, posterior half of third frontal gyrus, and under half of insula. _ Two explanations are offered for these cases. First, that the elements of the neoplasm have insinuated them. selves so gradually between those of the nerve tissue, or have displaced them with so little injury, that the func- tions of this tissue have not suffered. ‘This explanation applies to cases in which, instead of the cells of a nu cleus of origin, the fibres of a nerve tract have been dis- placed, as in some extraordinary cases on record in which a tumor has occupied nearly the entire pons, yet has oc- casioned no motor symptoms. The second explanation applies only to cortical centres. According to Exner, the different mechanisms of the cortex, though specially concentrated at certain localities, exert their influence somewhat beyond these limits, though with constantly diminishing intensity and effectiveness. Hence it is oc- casionally possible, though the main centre be destroyed, that its action may be supplemented by that of others habitually subordinate. In more than three-fourths of the cases of brain tumor, in addition to the diffused symptoms hitherto described, the patient suffers from perversions or abolition of one or more cerebral functions other than psychic ones. These are known as the focal symptoms. The simplest focal symptoms are those elicitable by per- cussion and auscultation of the cranium. In a certain number of cases, careful percussion awakens pain over a definitely limited area; and elicits also a peculiar tympa- pitic sound (Macewen), indicative of a marked thinning of the cranial bone, and due to the more extensive vibrations of air in the nose and mouth which occur when the skull is thinner than normal. In a few rare cases auscultation discovers another sound, an arterial murmur synchronous with the arterial pulse. This is conspicuously heard with aneurisms, but is by no means confined to them. It is analogous to the murmur which may be heard in ra- -chitic children or in those with open fontanels, or even in certain cases of intense anemia. Other focal symptoms, and far more frequently encountered than the foregoing, depend on the perversion or abolition of mobility or sensibility in one or more cranial nerves or spinal nerve tracts; or on similar alterations of one or more of the special senses. Among the latter, however, is to be ex- cepted the impairment of vision directly traceable to choked disc or optic neuritis. An intense interest has recently attached to these symptoms as a means of unravelling the physiological problems of the localization of brain functions. For this purpose, however, the study of tumors is much less valuable than that of other brain lesions, such as, for example, localized softening; for their limits are irregular, and their effects, through transmission of pressure, often diffuse themselves in structural or functional changes far beyond these visible limits. For clinical purposes, therefore, it is necessary to ascertain first what symptoms are generated by lesions really limited to certain localities; second, to what extent the complication of these by others, diffused or symp- tomatic of different localities, may aid us in diagnosing a tumor instead of any other focal disease. Focal symptoms are always unilateral at the beginning —a most useful criterion in distinguishing tumor from diffused disease of the brain. The appearance of symp- toms on the side of the body opposite to that where they first began indicates an extension of the tumor across the median line, except when parts are affected which are endowed with bilateral cortical innervation. Exten- sion of the growth across the median line, for obvious reasons, most frequently occurs at the narrowest regions of the encephalon, the pons and (though less frequently) the medulla. It is, however, also seen in tumors of the corpus callosum, but the second hemiparalysis is much slighter than the first. Case (Bristowe, Brain, October, 1884): Illness twelve weeks. Left hemiplegia, gradually extending to right side; then general paralysis, principally on the left side, ten days before death. Progressive drowsiness or stupid- ity, aphasia. Sarcoma occupied anterior two-thirds of fornix and corpus callosum, extending into the centrum ovale in both hemispheres, but principally in the right. In addition to these symptoms involving purely cere- bral functions, the functions of respiration and circula- tion are sometimes modified from the direct or indirect morbid influence exercised upon the medullary centres. Lesions of Motitity.—These are by far the most numer- ous, the most varied in character and in combination of all the focal symptoms of brain tumor. They belong to three different classes: First, irritative, including tremors, choreiform movements, local spasms,* and Jacksonian epilepsy; second, paralytic, consisting in the partial or complete abolition of motive power; third, ataxic, imply- ing inco-ordination among functionally combined move- ments. Irritative Lesions of Mobility.—A fine tremor or a clonic spasm, incessant or periodically repeated, is often seen, either in muscles which have already become paralyzed, or in those which become paralyzed at a later date. Case (Berger, Arch. der Hetlkunde, XIX. Jahr.): Woman, aged forty-eight. During a year, about every eight days, an attack of clonic spasms in the right arm, then paralysis of the same arm, followed by paresis of the buccal branches of the right facial; clonic spasms persist after paralysis sets in: death a week later. Tumor in left anterior central gyrus, compressing the posterior and second frontal gyri. Case (Berkley, Med. News, 1882): Patient with spasm of the left angle of the mouth for two and a half years, Sudden death from cardiac disease. Calcareous nodule three-sixteenths of an inch in diameter on the right as- cending frontal convolution, an inch and a half above _the fissure of Sylvius; the locality corresponds to Fer- rier’s centre for the zygomatic muscles. Tremors and localized spasms are valuable diagnostic symptoms; for, first, they are more frequent with tumors than with other localized brain lesions; second, they are more frequent in the cortex; and, third, they are espe- cially frequent in the motor zones. All these circum- stances are demonstrated by the following tables. The first is compiled from Exner’s collection of one hundred and sixty-four cases, exclusively of cortical lesions. Tumors of cortex (44 cases): Spasm, 3 = 6.5 per cent. ; spasm and paralysis, 14 = 31 per cent.; paralysis, 14 = 31 * The general epileptiform convulsions being a diffuse symptom. 439 Brain, Brain, per cent. ; no motor symptoms, 18 = 29 per cent. Total spasm, 17 = 38 per cent. Other lesions of cortex (100 cases): Spasm, 1 = .09 per cent. ; spasm and paralysis, 18 = 11.5 percent. ; paralysis, 62 = 56 per cent. ; no motor symptoms, 36 = 82 per cent. Total spasm, 14 = 12 per cent. Thus, in more than one-third of all cases of brain tumor, localized spasms or contractures exist at some period of the disease. When present, they indicate a greater probability of localization in the cortex than in any other part of the brain; and after that, in the region of the corpus striatum and thalamus opticus. In the table, the highest percentage falls to tumors of the peduncle; but this fact is offset by the great rarity of tumors in this region. TABLE V.—PROPORTION OF CASES OF SPASM WITH TUMORS. 3 el gies ease Seat. eA ees eo ere ee ea Hag % BS/ 8/2515) 3] 2 ass B°| a /ds)s|3|5| shes Zz Lie 2 & a Cortex— Central gyri.......... 39 AA Pla 10M 28 ay eal Parietal lobe (motor).| 11 he ff 1 veh stl BE} Total motor zone ..| 50 4 31 | 11 35 7 5 Frontal QyTl oie 14 2 1 4 Dili claliont Other latent parts....| 18 1 2 3] 23] 8 Per cent, Total Cortex ..5.. 0 77 G | 34) 1% |-41) 68) 20=25 Centrum ovale......... 124) 12) 22) 45) 34] 2% | 45=36 ‘Basal canvas. .— ose: 41 9} 10] 14] 19 | 46 S=19 Pedunele Parsee ocsee 10 il 5| 3 6 | 60 2= 20 Corpora quadrigemina.| 138 1 3] 2 30 C= be: ONS: his ceecieimicecusne 56 3 Ve [|code aki aes S14 Cerebellum .........++. 165 | 20| 12) 26| 32] 19 | 107=64.5 Medulla Heike dee sies stccee'e 30 8 2) 154) 10) 83 biG Ota) cretcinssveniianns 516 156 | 30 | 202 = 37.5 It is evident that spasmodic contractions of muscles may be caused by irritation either of the nerve elements of a motor centre, or of the fibres of a motor tract de- scending from it, but that the first condition is more favorable. A continuous fibrillary twitching is frequent in cortical tumors. But tumors of the pons and medulla are rarely accompanied by spasm; it seems that the liability to irritation increases higher up in the tract, and also when the latter is more incompletely invaded. Irri- tation of the skin over the affected muscles will often throw them into spasm. Paralyses of Motility.—These are especially character- ized, as a rule, by their gradual development, a circum- stance which is most useful in distinguishing brain tumors from hemorrhage. It does not, however, serve to differ- entiate tumors from softening, for in the latter the paraly- sis is also gradually developed. To a certain extent the paralyses of tumors share the peculiarities of those caused by other lesions of the same locality. As already stated, however, in the case of tumors, the paralyses are rarely purely typical through. out the whole course of the disease, because they con- stantly tend to encroach upon other regions than that in which they originated; and because their influence, by transmitted pressure and nutritive irritation, is apt at all times to diffuse itself considerably beyond the region which they visibly occupy. A paralysis which may seem at a given stage to be entirely atypical may, how- ever, exhibit in the history of its development peculiari- ties which point out the true nature of the disease. The local diagnosis is best assured when a localized spasm has passed gradually into a localized paralysis. The paralysis has been preceded by a slowly progressing paresis, or by tremor or spasm in the affected muscles, or has existed in one set of muscles, or in one limb, or in one or more cranial nerves; or there has been a combination of paralyses of such nerves with others of the extremities, 440 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. before the disease reached its complete evolution. Or, further, the very first appearance of paralysis may have been preceded by one or more diffused symptoms; or it may have been ushered in by an epileptiform convulsion or an apoplectic attack, remarkable for its brevity and incompleteness. Or a paralysis may declare itself at once, in a fully developed form, but isolated, as in one facial nerve, and after prolonged headache, attacks of vomiting, and change of mind or character of the pa- tient. The typical characteristics of the paralyses, ac- cording to locality, are as follows: Corter.—The paralysis, at the outset at least, is “dis- sociated,” monoplegic. One arm or one side of the face is affected, or the two together are affected on the same side. It is extremely rare that paralysis begins in the leg; but this extremity often becomes involved later, and then the patient suffers from a complete hemiplegia, difficult to distinguish at first from the common hemi- plegia due to hemorrhage into the internal capsule. It is very rare, however, that the paralyzed limbs become rigid. It is with tumors in this region that clonic spasms are most frequent, either before or during the paralysis. Symptoms of tumors of different regions of the cortex follow, approximately, the rules which have been laid down for other lesions, according as they occupy the “latent” or the motor zones. The latent regions are those parts of the brain in which, with rare exceptions, lesions produce no motor symptoms. ‘The motor zones are those whose lesions are always followed by spasm or paralysis, except ina very few cases, in which the absence of symptoms is explained by the extremely slow growth of the tumor, which allows nerve tissue to accommodate itself to increased pressure. When an “absolute field ” exists it will be found that, in all cases in which motor symptoms are absent, this field is entirely free from lesion. In the regions adjacent to these, lesions some- times do and sometimes do not producesymptoms. This fact, as already stated, has been explained in two ways —by the theory of transmitted pressure, and by the theory of a “relative field,” which contains motor mechan- isms of less degree of intensity and concentration than those belonging to the “absolute field.” The absolute motor zones are: First, for the upper extremity, the anterior central convolutions, especially the lower two-thirds, the upper half of the posterior central convolution, the paracentral lobule, and, in the left hemisphere, the greatest part of the superior parietal lobe, and possibly a few points on the occipital. Second, for the lower extremity, it is the upper third of both central convolutions and the paracentral lobule, and in the left hemisphere again the greater part of the superior parietal lobe. This “absolute field” is, accord- ing to Exner, surrounded by a relative field which oc- cupies the posterior half of the superior frontal gyrus, almost the entire convex surface of the other two frontal gyri, both parietal lobes, and the upper part of the oc- cipital lobe. This field belongs to both extremities. The centres for the muscles of the trunk have been placed by Horsley and Schiifer in the gyrus marginalis. Third, there is no absolute field for cither facial mus- cles or tongue, the mechanisms for both seeming to be diffused over the greatest part of the hemispheres. But. the seat of greatest concentration, for the facial nerve, exists at the lower half of the anterior central gyrus and the lower third of the posterior central; while a relative: field extends over the posterior half of both lower frontal gyri and the anterior part of the supramarginal gyrus. The principal centre for the hypoglossal nerve is the lower part of the anterior central gyrus and adjacent: part of the middle and inferior frontal gyri. Fourth, no definite cortical field has been outlined for either the motor-oculi nerve or the trigeminus. In regard to the first, however, it seems certain that all the branches. of both nerves are influenced by the centres of a single hemisphere. The zone for common sensibility coincides with the motor zone as above defined. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain. Fifth, the zones latent in regard to motor or sensory symptoms include all the frontal lobes, the temporo- sphenoidal lobes, the parietal lobe of the right hemi- sphere, and the occipital lobes. Lesions of these lobes may remain absolutely latent, and did so in 13 of Exner’s 44 cases of tumors, that is, in 29 per cent. But, even when unattended by paralysis or spasm, lesions of these latent zones are liable to be followed by such disorders of speech, of vision, or of hearing as lead to the localiza- tion, within their boundaries, of the centres for these im- portant functions.* In Table V. it will be seen that there were 9 cases of paralysis, with or without spasm, occasioned by tumors in the non-motor regions; the per- centage of paralysis to whole number of such tumors be- ing 387 per cent. Out of the whole number of cases of paralysis from 77 tumors of the cortex (51 cases), the vercentage belonging to tumors of non-motor regions was 17.5 per cent.; that of those belonging to motor regions (42 cases) was 54 per cent. of the whole, and 84 per cent. of the tumors of that region; while, finally, the probability that a tumor situated in the cortex would occasion some form or degree of paralysis is indicated by the relation of 51 to 77, or 66 per cent. Centrum Ovale.—A much larger percentage of tumors remain latent in this region than in the cortex, as, for example, 36 per cent., instead of 25 per cent. (see Table V.). The absence of symptoms is to be expected when the tumor neither occupies nor affects bundles of fibres coming from the motor regions of the cortex. In the following table Ladame’s and Bernhardt’s cases are com- bined, and show to what extent tumors situated in non- motor regions may yet inhibit the mechanisms of the motor regions. : TABLE VI.—PARALYSIS WITH TUMORS OF CENTRUM OVALE. MOTOR REGIONS. NON-MOTOR REGIONS. n n nD n a Bi a A = oF hae, Ps Seat. S a Fe Seat. FS Zz FA Es} =] 3S iso] a ray a a Pars centralis ante- Pars frontalis ..... 37 37 rior and _ posterior Pars occipitalis....| 10 23 (EEN RS) id eee 61 16 Temporal lobe .... 2 3 Other parts........ ar h PIGUA a eteteiniecers/s0i0's.0 61 16 ARO oaanneia 49 70 The paralyses which are associated with tumors of this region present nearly the same characteristics as do those associated with tumors of the cortex if they are near the surface; that is, they are liable to be monoplegic; but they resemble those of tumors of the internal capsule, if they approach the basal ganglion, in which case they may become completely hemiplegic, and may be followed by rigidity. Tumors in the anterior part of the centrum are chiefly indicated by motor symptoms, spasm. or paralysis; those situated posteriorly cause sensory symp- toms—hemianzsthesia, or pains on one side of the body. Usually a long period of paresis precedes that of com- plete paralysis. The percentage of cases of paralysis in tumors of the centrum ovale, whether calculated from the smaller ~ number of cases in Table VI. or from the larger num- ber in Table V., is about: the same, viz., 54 per cent. in the first case, 56 per cent. in the second. Basal Ganglia.—Tumors of the corpora striata, optic thalami, and lenticular nuclei occasion: hemiplegias, which often differ from those of hemorrhage in the same region, exclusively by their gradual rate of development. The paralysis is, however, sometimes monoplegic; thus, * The wide diffusion of the mechanisms for the motor-oculi nerve and the facial, which render their paralyses of little value in regional diagnosis, is probably correlated to the complex relations of these two nerves to the mechanisms of psychic existence, and their functions in the innumerable shades of facial expression. out of 41 cases, it was:confined to the facial nerve four times, to the arm once, to the arm and facial once, and to the leg once. It is extremely remarkable that large tumors may exist in this region without causing any symptoms whatever. This is the rule for tumors limited to the thalamus or to the lenticular nucleus. Acute lesions, such as hemorrhage in the latter ganglion, cause temporary hemiplegic symptoms, but these subside, probably because the function of the destroyed tissue is supplemented by that of other motor centres. But such temporary paraiyses are not seen with chronic lesions, as. for example, tumors, unless these are complicated by an accidental hemorrhage. But tumors limited to the corpus striatum will certainly cause paralysis if they involve the anterior two-thirds traversed by the motor tract of the internal capsule. It is injury to this tract which determines the phenomenon of “late rigidity ”; a phenomenon depending on the de- scending degeneration which reaches the spinal cord, and which, though so commonly seen after cerebral hemor- rhage, is not peculiar to that lesion, but only to the local- ity which it most frequently occupies. If a tumor involve the posterior third of the internal capsule, whose fibres pass between the corpus striatum and the thalamus, it tends to destroy the sensory fibres which pass in this locality (Charcot, Veysiére), and causes a hemianesthesia in addition to the motor paralysis. This complication is therefore of great use in establishing the diagnosis of tumors of this region, which from their encroaching tendencies are so liable to involve all parts of the internal capsule. It is possible that a transmitted irritation to sensory fibres has something to do with the high percentage of spasms observed in tumors of the basal ganglia (46 per cent., see Table V.). There were 24 cases of paralysis, with and without spasm, which is 58 per cent. of the whole number. Hemianopsia, or paralysis of some ocular muscles, oc- curs with such tumors of the thalamus as touch upon the corpus geniculatum externum. Athetoid movements and intention tremor are very characteristic of thalamic tumors. Still more so is Bechterew’s symptom, namely, preservation of the innervation of facial muscles for voluntary movements, with loss of the automatic move- ments involved in emotional expression,—as in laughing or crying. This isolated mimetic paralysis seems to be quite peculiar to lesions of the thalamus. Peduncle.—Asmight be expected, tumors of this region cause hemiplegic paralysis in almost all cases (eighty per cent.). Together with the extremities, the facial nerve and also the hypoglossus are usually involved. The most characteristic circumstance, however, is the paraly- sis of the motor-oculi nerve by direct pressure upon its trunk as it emerges in the interpeduncular space. The paralysis is on the same side as the tumor, that is, on the side opposite to the hemiplegia. The paralysis is usu- ally total, in which case there will be unilateral dilatation of the pupil, ptosis from paralysis of the levator palpebre muscle, and divergent strabismus from paralysis of the internal rectus. In other cases, one or more of these symptoms may exist alone. As the tumor grows larger it sometimes crosses the interpeduncular space, and com- presses the nerve on the opposite side. This important symptom existed in seven out of the ten cases of Ladame and Bernhardt. It isnot, however, absolutely pathogno- monic of lesions of the peduncle; for it results, with exactly the same forms, from every tumor of the inter- peduncular space; thus, from those springing from the base of the cranium. Corpora Quadrigemina.—Tumors of these bodies lie outside of the direct cerebro-spinal motor tracts, and thus produce much less definite motor symptoms. Some degree of paralysis existed in 5 out of 18 cases; in 1, paresis of the arm and facial nerve; in 2, a unilateral facial paresis; in 1, paresis of one leg; and in 1, paresis of one-half of the body. On the other hand, the motor-oculi nerve seems to be paralyzed as often as in the case of tumors of the pedun- | cles; a fact which might be expected from the proximity 44] Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. of the corpora quadrigemina to the nuclei of the nerves, which lie immediately below them. In 14 cases, diver- gent strabismus existed in 8 (5 cases of Bernhardt, 3 related by Nothnagei). In 1 other case, the abducens was paralyzed, so that internal strabismus existed (Gowers, Lancet, 1879). Cerebellum.—Absence of true motor paralysis, taken together with impairment of the power of equilibration, is highly characteristic of tumors of the cerebellum. Out of a total of 165 cases, only 38 showed any kind of paralysis (23 per cent.). This is almost the proportion in which the symptom is absent in tumors of the cerebral cortex. Excluding the cerebellum and corpora quadri- gemina, the probabilities of paralysis with brain tumor are expressed by the percentage 89, while for the cere- bellum and corpora quadrigemina alone the percentage is only 24. Tumors of either lateral lobe of the cerebellum cause of themselves no motor symptoms, even ataxic, and may be completely latent. Out of the 38 cases of paralysis the tumor occupied the middle lobe of the cerebellum in 4; in 5, one of the peduncles; in 15, though mainly situ- ated in a lateral lobe, it extended into the middle lobe, or else compressed the pons or medulla. The facial nerve may be affected either by an isolated, or by an alternating, or by a hemiplegic paralysis, in the rare cases in which hemiplegia occurs. The lesion is never really of cerebellar origin, but always secondary to encroachment upon the pons or medulla. Pons Varolit.—In this locality tumors produce the most extensive and also the most complex combinations of paralyses. They are occasionally paraplegic, and not infrequently they become, little by little, generalized throughout the four limbs. This creeping generalization is highly characteristic of tumors of the pons. On the other hand, only cranial nerves may be affected. Case (Wernicke, Archiv f. Psychiat., Bd. vii.): Pa- tient aged fifty-eight years. In July, headache, diplopia; difficulty in opening and shutting mouth. By end of August, paralysis of left facial nerve, including upper branches; rigidity of left masseter; eyes persistently deviated toward the right; diminished sensibility of face and head on the right side, that is, on the side opposite to the facial paralysis. Death occurred in October with- out further motor affection. Section discovered a tumor on the floor of the fourth ventricle, on the left side of the middle line. Associate nucleus of facial and abducens completely destroyed; left facial nerve nucleus, as also part of the fibres of the right trigeminus, destroyed. After the frequent generalization of the paralysis, the remarkable paralytic symptoms of pontine tumors are: 1. The coexistence of hemiplegic paralysis of the ex- tremities with paralysis of one or more cranial nerves on the opposite side of the body; alternate paralyses. 2. The occurrence of a persistent conjugate deviation of the eyes, thus distinguished from the same symptom in lesions of the hemispheres, where it is always transitory. To these positive symptoms may be added an important negative characteristic, namely, the nearly complete absence of local irritative symptoms, and, to an even more marked degree, of general convulsions. The alter- nate paralyses are produced by tumors in the lower part of the pons, which injure the nerve nucleus or compress the nerve trunk on the side on which they are situated, and injure the general motor tracts of the limbs previous to their decussation, so that the resultant hemiplegia fol- lows the usual law for cerebral paralysis, and appears on the side of the body opposite to the lesion. When the tumor occupies the upper segment of the pons, anterior to the cerebral peduncles, the facial paralysis will be on the same side as the limbs, since it depends not on a lesion of the nucleus or nerve trunk, but on one involv- ing the central fibres after their decussation. When the tumor occupies the region of the abducens nucleus, the movements of both eyeballs to that side are paralyzed. The double nature of the paralysis proves that the nu- cleus common to the abducens and internal rectus has been affected. 449 In the most typical cases, all the branches of the faciai are paralyzed, including those innervating the orbicularis palpebre. The eye cannot be closed, and the patient presents the appearance of Bell’s paralysis. The electric excitability of the nerve may then be diminished. How- ever, neither of these last conditions is invariable, even when the paralysis is alternate. Double facial paralysis is extremely rare. It is lesions of the pons which have furnished the explanation of the remarkable phenomenon—conjugate deviation of the eyes —which for a long time puzzled pathologists. This de- viation implies paralysis of the abducens nerve of one side, supplying the external rectus, and coincident paraly- sis of a branch of the motor-oculi nerve supplying the internal rectus on the opposite side. The apparent re- moteness from each other of the nuclei of origin of these two nerves rendered this phenomenon extremely difficult to understand, until the discovery was made, in the pons, of a common nucleus, which unites fibres of the abducens with fibres from the lower nucleus of the motor- oculi on the opposite side. Destructive lesions of this associate nucleus are followed by a permanent conjugate deviation, as in the case (Wernicke) above quoted. It becomes evident that the transitory deviations of the eye, frequently seen immediately after an attack of hemor- rhage into any part of the brain, are due to a remote shock propagated to this same nucleus. The abducens nerve is not infrequently paralyzed alone, causing a converging strabismus of the affected eye. Isolated paralysis of the motor-oculi nerve is much more rare, and is seen only when the tumor or its influ- ence extends above the pons into the cerebral peduncles, or above them to the nerve nuclei. Ptosis, from isolated paralysis of the levator palpebre branch, has sometimes been observed alone, and, so far, in cases of tumors, but not in those of any other lesion. This symptom would, therefore, be useful in differential diagnosis. Paralysis of the hypoglossus isnot rare. Itis indicated by an impairment of the voluntary movements of the tongue and by disturbance of speech, dysarthria. This paralysis alternates with that of the extremities. It is distinguished from progressive bulbar paralysis by ab- sence of atrophy of the tongue. The motor branch of the trigeminus is sometimes paralyzed, more often irritated, causing, in the latter case, spasmodic trismus or clonic convulsions of the muscles of mastication. Difficult deglutition is also sometimes present, but does not seem to be attributable to paralysis of the pharynx muscles, but rather to be a secondary consequence of paralysis of the tongue and of certain muscles innervated by the facial nerve, the styloglossus, digastricus, and stylohyoideus (Nothnagel). The following table exhibits the various combinations of paralyses, which have been observed with tumors of the pons. TABLE VII.—MOTOR PARALYSES WITH TUMORS OF PONS (56 CASES). Cranial nerves Combination No motor alone. Limbs alone. of limbs and cranial symp- nerves. toms. 3d nerve ...... 2;Hemiplegia... 7 On same side, 7th nerve..... 3}Paraplegia.... 3]/Hemiplegiaand 38d and 6th Four extrem- 7th nerve........ 4 nerves ...... Hee in YB Aye aides 2| Alternate paralysis. 6th and 7th |Armalone.... 1/Hemiplegia and— nerves ...... 3 30 DELVE sass 2 7th and 12th 6th nerve ....... 3 4 nerves...... 1 7th nerve........ 4 3d, 7th, and 3dand 6th nerves 1 12th nerves.. 1 3dand7th nerves 3 3d, 5th, 7th,and 6th and ‘ith 12th nerves.. 1 DCIyes Prescee 5 3d, 6th, and 7th NELVES es ncnnee 1 3d, 5th, 7th, and 12th nerves... 1 3d, 6th, 7th, and | 12th nerves... 1 Total...... 13 TOTAL ese! Total rsccecetrn 25 4 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, The number of cases in which the cranial nerves or those of the limbs were paralyzed independently of each other is, in this collection of cases, exactly equal. The number of cases of combined paralyses is just double that of either of the classes of isolated paralyses. Among the cranial nerves, the liability of the facial is evidently the greatest; it was affected, alone or in combination, twenty-four times; the abducens sixteen times. Medulla.—In this region the liability to paralysis again diminishes. Tumors of the medullaare not infrequently confined to the floor of the fourth ventricle, so that the motor tracts and nuclei are both left uninjured. In this case, the patient escapes all paralysis; indeed, he often remains with singularly few symptoms for the subject of an organic disease seated so near to vital nerve centres. Out of 30 cases, 12, or nearly half, remained free from motor symptoms. In one case, so far unique (Erichsen, Petersb. med. Zeitschr., 1870), a bilateral paralysis of the vocal cords was noted, due to lesion of the accessory nerve. TABLE VIII.— MOTOR PARALYSES WITH TUMORS OF MEDULLA (30 CASES). Nene ig hea Extremities. Combination. Negative. 3d nerve...... 2|Hemiplegia ... 1|/Hemiplegia and— 7th nerve ..... 2|Three extremi- 6th nerve ....... 3d and “7th nts": Wane art Same side. nerves...... 1/Paraplegia.... 2|/Hemiplegia and— “th and ilth =(|General....... 2| 6th nerve (alter- nerves ...... NAtiNg) wees 1 5th, 6th, and 3d, 6th, and 7th 7th nerves... 1 MIGLV eS teneees 1 od, 7th, and 12th NIONV.OS orsievelejerere 1 12 7th and associ- ated 3d and 6th NOVV CS vreau. 1 Motalls ss... 7 Totale.aer. 6 "Otel saesaae as 5 12 The third form of motor lesion is atazia. This form of lesion is principally seen with tumors of the cerebellum and corpora quadrigemina; the latter, pos- sibly from the connection of these bodies with the cere- essential that the middle lobe be involved or indirectly affected ; tumors limited to a lateral lobe are characteris- tically latent. Forced movements, or inclinations of the body or head to one side or the other, are sometimes associated with tumor in a lateral peduncle on the corresponding side. A tendency to fall forward or backward has been asso- ciated with the situation of the tumor in the anterior or posterior extremity of the upper or lower processus vermiformis (middle lobe). A combination of ataxia with ocular paralyses was pointed out by Nothnagel to be highly characteristic of tumors of the corpora quadrigemina. Recently there has been described an ataxia in tumors of the frontal lobes closely resembling that supposed to be special to the cerebellum. It is due to paralysis of the muscles of the trunk, whose centre of cortical innerva- tion is placed by Horsley and Schiifer in the gyrus mar- ginalis, thus in the middle line. Hence with a unilateral tumor there will be bilateral ataxia. LESIONS OF SENSIBILITY.— With the exception of head- ache, already described as a diffuse symptom, alterations of sensibility are very much less prominent in the symp- tomatology of tumors than alterations of motility. It is evident from this table that, in the cortex, the seat of sensibility coincides with the seat of motility. Pain or anesthesia rarely exists without paralysis, or ex- cept in connection with tumors situated in the motor zones. The liability to pain, other than headache, with tumors of the centrum ovale, is very slight (5 cases out of 124).* It has already been pointed out that tumors of the basal ganglia will cause hemianzesthesia in paralyzed limbs, provided they involve the bundle of fibres which pass in the posterior third of the internal capsule; other- wise they will not be attended by lesions of sensibility. The table, therefore, expresses the probabilities of this precise situation, in giving the proportion of cases of pain or anesthesia as eight out of thirty-nine, or twenty per cent. The highest percentage is with tumors of the pons, and the next highest, if the few cases of tumors of the peduncles of the cerebrum be excluded, is with those of the medulla. In these places occur pain and anesthesia TABLE IX.—LESIONS OF SENSIBILITY WITH BRAIN TUMORS. WITH MoTOR PARALYSIS. WITHOUT MOTOR PARALYSIS. 4 gS eS 6 |% 28s Seat. Unilateral. Double. Trigeminal. Unilateral. Double. Trigeminal. 5 § aac ————— | | | 2 &p Bg a Angs- .. | Anges- n Anges- : Angs- .. | Ances- -, | Anges-| © : 2 ood Pain. thesia, | Pain. thesia. Pain thesia Pain thesia Pain. thesia. Pain. thesia.| 4 z = a” ‘Cortex (57 cases): ; CAMA VTP... s anccte es 6 v4 1 Saas 11 [14 =% Parietal gyri...c..+..-- 1 3 il 12 | 5=2% “ay Say eee ee are 1 Oe 9|1=10 ERINDOLAllstece asec cvccs|)) oereeece 2 1 L138=%5 WCCMNEAL ce ccclicesccecsee|| cecenece sees ete 1 O="0 Entire cortex ........ 8 15 eee her 34 |28 = 40 ‘Centrum ovale (124 cases) 5 14 mtd Anite 105 |19 = 15 Basal ganglia (39 cases) . 1 5 ony btefats 2 SIs 2p Peduncle (10 cases) ...... a a ; a a0ae ; anne 1 5 | 5=50 Pons (51 cases) .....++- Db iden a oH bed [27 = 62.5 Medulla (30 cases) ....... 4 5 2 1 1 baler 1 16 [14 = 46 | ‘Cerebellum (167 cases) ... 2 7 1 1 4 5 5 ae isi eae, Seen £42 25 = 14.5 Corpora quad. (18 cases) . 1 aoe Ae 1 ROE = |enoceul Wisconoel latce pepe edie [eth Total (491 cases) ..... Sie 6F of ail 59 = 12% 5 = 1% 4 = 0.8%| 10 = 2¢||8 = 1.2/8 =1.6%| ....] ....| 1 368 Percentage of lesions of sensibility in all cases equals 25. bellum through the superior cerebellar peduncles. In the pons and medulla, the advent of paralysis is often pre- ceded for some time by a staggering or reeling gait “like a drunkard’s.” This same symptom is very conspicuous in tumors of the cerebellum, and, when associated with the negative symptoms of absence of motor or sensory paralysis, points very strongly to tumors of this region. For the development of the symptom, however, it is in the facial range of the trigeminus. When similar symptoms are excited by tumors of the cerebellum, it is only because the pons or medulla has been compressed. *The percentage of headache, however, was sixty-six, the highest after the cerebellum and rare cases of corpora quadrigemina. The liability to headache, from distention of the dura mater, is constantly seen to bear no proportion to perversions of sensibility due to lesion of sensory tracts or centres. 443 Brain. Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Trigeminal neuralgia or anesthesia is, like cramp or paralysis of the masticatory muscles, a most important symptom for helping to localize a tumor in the posterior cranial fossa. It is noticeable (see table) that trigeminal anesthesia has hitherto been observed on the side op- posite to the paralysis, while anesthesia of the extremi- ties has nearly always existed on the same side. The cerebellum and corpora quadrigemina show the same minimum liability to lesions of sensibility as they do to motor paralysis. Their precentage, almost alike for the two cases, is, however, not lower than that of the centrum ovale. LESIONS OF THE SPECIAL SENSES.— Vis¢on.—Disturb- ances of vision are extremely frequent as symptoms of brain tumor, and are of three kinds: First, atrophy of the optic papilla as a consequence of choked disc, and therefore as a remote consequence of increased intra- cranial pressure; second, deviations of the eyeball or eyelids from isolated or combined paralyses of the nerves supplying the ocular muscles, the third, sixth, and seventh; and finally, third, amblyopia or amaurosis, re- sulting from direct affection of the optic nerve in its course through the cranium, or at its cerebral centres, the mode of development being therefore almost precisely an- alogous to that of paralysis of any other nervous tract by direct compression. The first two kinds of ocular defect have been sufficiently described; the third comprises two different kinds of lesions, those affecting (by compression) the optic tract or chiasma, and those which affect the optic stations at the posterior extremity of the thalami or at the corpora quadrigemina, or else at the final visual centres of the cortex. The optic nerve or chiasma is liable to compression from tumors arising from the base of the cranium or from the hypophysis, and also from tumors of the peduncle; an acute descending optic neuritis, with atrophy of the papilla, is usually excited. When one tract or one side of the chiasma is compressed, hemiopia results, a phenomenon dependent on the semi-decussation of nerve fibres which takes place in the human chiasma. Thus pressure on the right side beyond the chiasma, of such a nature as to injure the fibres of one tract, will abolish vision in the right half of both eyes. A tumor in front of the chiasma may cause temporal hemiopia of both eyes, since it injures fibres coming from the nasal half of both eyes. There is no way in which a double nasal hemiopia can be produced by tumors at the base of the brain. Tumors of the thalamus might be expected to affect the sight from lesion of the corpus geniculatum, with its branch to the optic tract. Asa matter of fact, how- ever, blindness is not very common from tumors of this locality—only 5 cases out of 26 (19 percent.) As already mentioned, hemianopsia is seen with tumors of the thal- amus, when they involve the corpus geniculatum exter- num. ‘Tumors of the corpora quadrigemina, however, have an immensely large portion of cases. Out of 11, 9 showed either amblyopia or amaurosis, 5 with and 4 with- out choked disc (81 per cent.). Visual defects from lesions of the cortex are extremely interesting in connection with two physiological prob- lems, viz., the question of a second decussation of optic- nerve-fibres in the cerebrum (Charcot), and that of the localization of the mental centre of vision. This centre was placed by Ferrier at the angular gyrus, as an infer- ence from direct experiment upon the brain of monkeys. But Exner, on the authority of four cases of lesion reach- ing to the cortex, of which two were tumors, places the visual centre in the first and second occipital gyri—the cuneus and adjacent part of the lobulus quadratus. Case (Gowers, Lancet, 1879): Visual hallucinations of a peculiar nature, associated with some degree of am- blyopia, affecting both eyes, but more markedly the left. Tumor occupying first and second occipital gyri, posterior half of superior and inferior parietal lobes, the cuneus, and a part of the lobulus quadratus. Case (Jastrowitz, Centralbl. fiir prakt. Augenheilkunde, vol. i, 1877): Paralysis of both right extremities and 444 -and visual hallucinations of various kinds. facialis; aphasia, with agraphia; hemianopsia dextra. Tumor of the left occipital lobe, principally in the occip- ital gyri and the precuneus. Case (Pooley, Arch. f. Augen- und Ohrenheitk., Bd. vi.): Together with various characteristic symptoms of brain tumor in a syphilitic man, extensive binocular hemianopsia. Tumor in posterior lobe of left hemisphere, surrounded by extensive zone of softening. Left thala- mus completely softened. A tumor of one hemisphere may thus cause’ double hemiopia, a single or double amblyopia or amaurosis, The double ~ hemiopia from unilateral lesion, has been interpreted asa proof that, arrived at the cerebral hemispheres, optic fibres which had decussated in the chiasma, recrossed to the op- posite hemisphere, thus finally arriving at the same side of the retina as that from which they started. Hemiopia is habitually unaccompanied by choked disc. Crossed homonymous hemianopsia is the characteristic local symptom of disease of the occipital lobes. The symp- tom occurs also with lesion of any portion of the optic tract, from the chiasma to the occipital cortex. When the lesion is in the medulla of the left occipital lobe, to the hemianopsia is added another important symptom complex, namely, alexia and optic aphasia. It is deter- mined by injury to the association tracts running through the left occipital lobe from the occipital convolutions on both sides to the speech centre in the left superior tem- poral convolution. The patient recognizes objects by sight, but is tnable to name them, unless he either feels, hears, smells, or tastes them. He cannot read words, but can write spontaneously and under dictation. Mind blindness indicates with certainty lesion of the occipital lobes (Bruns). Six cases of amblyopia and amaurosis have been ob- served with cortical tumors, unaccompanied by choked disc. These are all to be attributed to a lesion of the visual centre; and, when located in the frontal lobe, the lesion must be regarded as indirect. The amaurosis or hemiopia, with tumors of the centrum ovale (thirty-nine cases, or thirty-one per cent.), probably always implies a transmitted lesion of the cortical visual centre. Of the two cases of hemiopia, referred to in table X., one is used by Exner and Nothnagel as documentary evidence in support of the theory of a visual centre in the cortex of the occipital lobe, but it is placed by Bernhardt among the tumors of the lobes. The total percentage of blind- ness is higher with tumors of the cerebellum than with those of any other locality, except the corpora quadri- gemina. Out of 91 cases there are 41 with some degree of blindness (45 per cent.). Of these, 23, or nearly half, are without choked disc; the blindness being therefore due to the direct action of the tumor upon some visual centre. It seems most probable that the centre affected is that of the corpora quadrigemina; the influence being transmitted through the superior cerebellar peduncles. The high percentage of blindness in the two localities so especially liable would be shown, therefore, to have the same significance. Tumors of the pons and medulla also determine amaurosis otherwise than by choked disc, through direct upward pressure upon the corpora quad- rigemina. The direction of the transmission is the same as for the upper (unassociated) nucleus of the motor-oculi nerve, which lies just below the corpora quadrigemina. Out of a total of 51 cases for medulla and pons together, there are 14 cases of amblyopia or amaurosis, or 27 per cent. To judge from this table we should infer that the chances of amaurosis in brain tumor were exactly equal, whether choked disc existed or not; but that the chances of amblyopia were three times as great without the choked disc as with it. This probably means that if choked disc occur, the impairment of vision which may have been initiated independently of it, by the direct in- fluence of the tumor, will rapidly increase to. complete blindness: whereas, without this local complication, the visual defect may for a much longer time, or even alto- gether, remain partial and incomplete. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, TABLE X.—LESIONS OF VISION (IN 369 CASES). ool a wel ra > 5 WITH CHOKED DIsc. WITHOUT CHOKED DIsc. aye peers ae 2 ; : ; Z “oe =F ai ie ke i (mie gee z sss) 2 1-8) | 8 ol ea aa eee mee 25 ae dha Hh ce 3 8 Hemiopia. | 4 . $ |S5F || Sg a2 S o S| | q q 5 ae = S a = < a 4 < oe od 8° Z SURREAL wa ccicie ia e's ein neo sie 1 acme | wiaseerttd ears < 3 20 BUSES er ccslate's|e1e 6. s:e.0:0 6 0,0.0700. iL aes F 3 2 n 12 MOIloesciess cokes ensees ses eitetereste i! nor j 8 SCR TECIREI ET Yoreclarcisieie sieves | oie cies imate me eiteent d-cee. Ml eleeier Il). esses ove ete eee OF 3 SIAMIPOEA Satainaieisciececics elses 8» afters end Abe Rea reece Watsees cote wate doele AGL 1 Maer Entire cortexX...........0+.. . BG |] eee | wees 3 Da ON esieceiots cae 4 2 10.5 16 4 43 Centrum ovale ......:..600. COE essomrin MOR ie eer |e fete te Sis aan ie Le BLA 12 70 ASO CANOE. sisa svieea sa. 26 nee eyarcel alll W | teisteletace ave 4 1 19 19 2 18 Cerebral peduncle.......... 10 i nage verccuar| meo rere cree 2 : : Ser Sites 7 PAE eMe Peters iste cis tieves: sieve cs 30 1 3 TSR oil wiccreecs 6 20 33 2 18 MEG Aits sce scec assesses ce 21 Ano RV iD etnies 1 3 19 2 15 PIETODENAN Tots) orsio (0 oisisis, 0.010.010 91 4 “14 EOE || Wm ereereyecete 9 14 25 45 11 39 Corpora quadrigemina ..... ST erate 2 3 pe I adeetndnd 3 a 36 81 1 1 MME eetetateiclctels sais. clsie' siete BBO) Gece 12 BU AM Rete el “nates dels 42 36 38 254 Total lesions of vision = 127 in 369 cases = 34 per cent. Hearing, Taste, and Smell.—All these special senses together are less frequently affected than is vision alone. Out of a total of 869 cases of brain tumor, lesions of vision existed in 127, or 84 per cent. But ina total of 561 cases (which include Ladame’s), hearing, taste, and smell were altogether affected only in 67, or 12 per cent. In 46 out of these 67 cases the patient suffered from either tinnitus or deafness, the latter rarely complete. In 29 per cent., the tumor was situated in the cerebellum. This fact tends to confirm, if need be, the recent ana- tomical demonstration, which traces the central fibres of the acoustic nerve to the cerebellum. By far the highest percentage of disturbance of hearing is exhibited by tumors of the corpora quadrigemina. It is singular that reports of tumors of the frontal lobes so rarely mention symptoms indicating lesion of the olfactory tracts. It would seem that an indirect influence or diffused pressure is insufficient to pervert the sense of smell; this is af- fected only by actual disorganization of the tracts. Ina few cases, anosmia, associated with frontal headache, psychic disturbance, and absence of motor or sensory paralysis, has been a valuable symptom which correctly pointed to tumor in the frontal lobes. But anosmia has also been observed with a tumor of the supramarginal convolution. The sense of taste, though controlled by two medullary nerves, usually escapes injury, even with tumors of the medulla. Unilateral paralysis of the acoustic nerve, with correlative deafness, is strikingly frequent in tumors of the cerebellum. TABLE XI.—LESIONS OF SPECIAL SENSES (561 CASES—369 FOR VISION). oe | 2 lee] # oad dt Seat of tumor. = g a & a & S/S Woeles tess ise Ay s Ay > Ay Cortex (59 cases) ..........- 1 1.5 4 7 9° | 16.0 Centrum ovale (192 cases) .. 8 4 3 89 | 31.5 Basal ganglia (41 cases) .... 2 4 oe 5 | 19 Peduncle (3 cases).......... Bia Pies ia 3 Wace Corpora quad. (13 cases).... 4 30 at 9 | 81 Cerebellum (167 cases)...... 26 | 15 2 1 41 | 45 ONS ODI CASES) \scaics bese sees 3 5 9 16 10 | 33 Medulla (80 cases) .......... 2 6 3 10 4 | 19 ME DESI Nerr ttatctets's\s.<) o\0ie/sla'«.s)si¢ 46 8.0 21 8.5 || 120 | 21 Disturbances of Language.—These symptoms were formerly confounded either with symptoms of mental alienation or else with difficult articulation due to tongue paralysis. But their interest and importance have been greatly widened by the modern discoveries that a patient may retain other mental conceptions yet lose that of spoken or written speech; and that the generic aphasic defect may be resolved into several modes: motor aphasia, sensory aphasia, agraphia, alexia. The cerebral region belonging to the faculty of speech occupies an extensive area in the left hemisphere, including the third frontal convolution, the insula, the posterior end of the first temporal convolution, the adjacent parts of the gyrus angularis and occipitalis sinister, together with sub- cortical association tracts. Tumors in the right hemi- sphere may also occcasion speech disturbance, when from their considerable size they compress the left hemisphere; or when they cause a distention of the opposite lateral ventricle; or because, as Oppenheim asserts, the right hemisphere participates to a real though subordinate ex- tent in the function of speech. When a disorder of speech has been a very early symp- tom of the tumor, it constitutes a valuable means of local diagnosis. Nevertheless speech symptoms not infre- quently fail though the tumor be situated in a speech centre; while, on the other hand, any form of aphasia may be caused by tumors at a distance acting on the speech regions by transmitted pressure, or encroaching on them in the course of their growth. With tumors of the central or frontal convolutions the aphasia is some- times preceded by a bradyphasia; or the patient finds a difficulty in beginning words, or in speaking above a whisper. When aphasia occurs with tumors of the left occipital lobe, or complicates an alexia or hemianopsia, it is always a sensory aphasia. Tumors of the third frontal convolu- tion are liable to produce spasms of Jacksonian epilepsy in the face, tongue, jaws, and larynx. From the foregoing analysis of the causation and especial probabilities of diffuse and focal symptoms, it is possible in a given case to answer the two questions: first, Is there a brain tumor present? second, In what part of the brain is it situated? I. ExisTENCE OF Brartn Tumor.—Although a tumor of the brain may develop during either childhood or ado- lescence, let us suppose it to have begun its growth in an individual of middle age, who perhaps has shown a tendency to tuberculosis. In such a case we can assume that the clinical picture will be somewhat like the fol- lowing: For weeks or months the patient will suffer from persistent or periodic headache, usually localized at one spot; the pain is peculiarly severe, and is increased by percussion. After a time there will be attacks of vomit- ing, which sometimes coincide with the most intense paroxysms of pain, and sometimes do not. These at- tacks, furthermore, seem to bear no relation to the char- acter of the food taken, or to the condition of the diges- tive organs; they do seem, however, to be dependent upon changes in the position of the body, as, for example, from the recumbent to the upright position. As in the 445 Brain, Brain, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. case of sea-sickness, the attacks are sometimes incoerci- ble. They are associated with vertigo; and in turn the ‘vertigo may occur independently of either the headache or the vomiting. It is apt to occur at intervals, and is often chronic in character. After the symptoms which have just been enumerated have lasted for a variable length of time, the patient’s gait becomes uncertain; he reels or staggers, or shows a tendency to fall forward or backward. This tendency sometimes increases until complete loss of equilibration renders the patient unable to stand, though he may be entirely free from paralysis. The muscles of one side of the face or of one arm begin to twitch, or even to be agitated by clonic spasms, which either may persist all the time, except during sleep, or else may recur in periodic paroxysms, followed by paresis, gradually increasing to paralysis in the same muscles or in others, e.g., in the arm or leg, after twitch- ing of the muscles of the face. The progress of the paralysis is apt to be interrupted by one or more convul- sions, or by attacks of apoplexy or of loss of conscious- ness; or one of these may usher in the first signs of paralysis, which at the outset may be complete, facial, monoplegic, or hemiplegic. Paresthesia or ansesthesia is next likely to manifest itself in the paralyzed limbs, or on the side of the face opposite to these. Afterward the symptoms succeed one another in about the following order: alternate paralysis of cranial nerves and extremi- ties; deviations of the eyeballs, isolated or conjugate; dilatation of the pupils, ptosis, much more rarely ap- pearance of Bell’s paralysis; occurrence at this time of diplopia, hemiopia, or amblyopia, gradually increasing to complete amaurosis; much more rarely deafness or anosmia, and the discovery of choked disc before or af- ter the development of ocular symptoms; progressively increasing modification of psychic character—at first marked irritability, then impairment of mental powers, loss of memory, apathy or hallucinations, maniacal ex- citement, and melancholic insanity ; before or at the same time with the appearance of this mental change there will be lesions of speech, dysarthria, aphasia, or word- blindness, the two latter often suddenly developed, as after an embolus, the first proportioned to the degree of tongue paralysis and gradual. A patient presenting the foregoing assemblage of symptoms, all progressively in- creasing, has, with very great probability, a brain tumor. In addition, is to be noted the freedom from pyrexia, and usually from changes in the rhythm of either pulse or respiration. The gradual, sometimes rapid, emacia- tion, the fact that acute accidents, though often followed by an exacerbation of existing symptoms, or even by the first appearance of new ones, have nearly always been preceded by others which have established themselves insidiously, are circumstances important to the diag- nosis. This being the general picture of the disease, individual cases are framed by the special emphasis of one or more symptoms, or the obliteration of others. The individual peculiarities depend upon (1) the locality of the tumor, (2) upon its rate of growth, (3) upon its complications, and (4), only to a very slight extent, upon its nature. Peculiarities due to Locality.—These may be divined approximately from such an analysis as has already been given of the symptoms proper to lesions of each given locality. The a priort judgment must, however, be modified in view of the tendency of tumors to encroach, in growing, upon territories adjoining their original seat, and also in view of the frequent diffusion of their influ- ence beyond any situation which they may occupy. The following summary of symptom groups is arranged in the order of characteristicness. It does not correspond to the order of frequency of locality, which, as indicated by the combined tables of Ladame and Bernhardt, would be as follows: CONTIN OV ALG i eisiclelestere sinceinictoisielotste/aloleistetey 192 = 29 per cent. Cerebellaninl sss vein. cic evoivatets wceiste cleraraereloteciets 167 = 27 4 ICOTTO KS: kecoiclelaeiejpipseiargereleicterd ates se acelin eivteniotor 74=11 A Cente ween Basal Panga. ye sevens eve miutefelaiainisinielsiaraleis/ alot 446 Meduila rates crc ioleiaa weesisicemprteinneeiemiere ette 30 = 4 per cent. COrpora, QUAGTIPEMINA tenes colette s cies 18. = 2 ies Cerebral peduncle. c.s.; seem. amerie eee eer 10") ee Extra-cerebral (including pituitary gland). 71=11 es 649 But if we consider localities in the order of distinctness with which a tumor in them may usually be recognized. the order would be as follows: cerebellum, pons, cerebral peduncles, cerebral cortex, basal ganglia, corpora quad- rigemina, medulla. Locau Draenosts oF Tumors.— Tumors of Cerebellum. —The most characteristic symptoms occur when the tumor involves the middle lobe. Headache is early, severe, and prolonged, often occipital; vertigo and vomit- ing are prominent; they may be for a while the only symptoms; epileptiform convulsions of great violence, but not often repeated; choked disc occurs early, preced- ing amaurosis, but also followed by this; peculiar ataxia, resembling the gait of a drunkard; loss of equilibrium in standing, with tendency to fall forward or backward; often paralysis of one abducens combined with that of op- posite rectus internus; absence of other motor paralysis or of general sensory symptoms; loss of patellar reflexes; the intelligence clear till toward the end, when apathy deepens gradually into coma. From pressure upon the pyramids and the cerebral nerves, alternate paralysis is frequent, as are cardiac and respiratory symptoms from pressure on the medulla. From the same cause, singultus, irre- sistible yawning, salivation. All the nerves at the base of the brain are liable to be irritated and subsequently para- lyzed. Varied symptoms in the area of the trigeminal area; pains in the tongue, simulating a gouty neurosis; neuroparalytic keratitis; paralysis of the masticatory muscles; clonic spasms in the territory of the facial and vago-accessorius, in the larynx, soft palate, and pharynx. Unilateral paralysis of the tongue from pressure on the hypoglossal may be added to unilateral paralysis of the acoustic nerve. When a lateral lobe of the cerebellum is the seat of the tumor, the symptoms are apt to be complicated late in the disease by hemiplegia or hemianzsthesia or both, or by alternate paralysis. Cerebellar tumor is distinguished from pontine tumors by the marked ataxia which precedes the paralysis. Tumor of Pons, Lower Half.—Uncertainty of gait, rather than ataxia, succeeded by isolated paralysis of third, or sixth, or seventh, or twelfth nerve, not preceded by symptoms of irritation in the muscle which it supplies; or else alternate paralysis, passing into incomplete para- plegia or general paralysis; permanent conjugate devia- tion of the eyes; amaurosis in a third, choked dise ina fifth, of the cases; entire absence of convulsions; head- ache, vomiting, and vertigo milder than in cerebellar tumor, or absent, but intelligence affected in half the cases. Tumor of Upper Part of Pons.—Combination of symp- toms proper to cerebellum and pons, as lobe of cerebellum is frequently compressed. Isolated rather than conjugate paralysis of the third nerve; paralysis of the facial on same side as hemiplegia: irritation of the trigeminus, sometimes of motor root, occasioning trismus; or of sensitive root, causing neuralgia on the side opposite to the hemiplegia. Sudden death is especially frequent in tumors of the pons. In contrast with tumors of the cerebellum, sensory symptoms are manifold in tumors of the pons. The most common isa simple anesthesia of the extremities. on the side opposite the tumor; but sometimes without alteration of the cutaneous sensibility, the muscular and stereognostic senses are impaired. The tracts for the cutaneous sensibility and muscular sense are separated. Besides the Gubler form of alternate paralysis, when the facial is paralyzed on the side of the tumor, the hypoglos- sal, and extremities on the opposite side, there is occasion- ally seen a lesion of the trigeminus on the side of ‘the tumor with hemiplegia on the opposite side. “Lesion of the motor root causes paralysis of the masticatory muscles with atrophy and electrical degeneration; lesion of the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Brain, Brain, sensory root causes first neuralgia, later anesthesia. Keratitis neuroparalytica also occurs. Variations in the form of paralyses are frequent and liable to be misleading. There may be no paralysis of the extremities, but only of cranial nerves, especially the peculiar lesion determining permanent conjugate devia- tion of the eyes. Oran entirely cerebral form of hemi- plegia may exist,or the lesion may limit itself to the nerve nuclei of the pons, paralyzing them without causing mo- tor hemiplegia, but crossed anesthesia or ataxia, or, through irritation of the pyramidal tracts, crossed inten- tion tremor. Only for a short time does a pontine tumor remain unilateral, but soon it crosses the median line and occasions much complication of the symptoms. The cranial-nerve paralyses become bilateral. The conjugate deviation of the eyes to one side is neutralized by a second on the opposite side, so that the ocular bulbs remain rigid - ly fixed in the middle line. All four extremities and both hypoglossal nerves become paralyzed. Since the coronal fibres which pass through the pons from both cerebral hemispheres are injured, the medullary nerves dependent upon them—the glossopharyngeal, vagus, and accessori- us—are paralyzed, a pseudo-bulbar paralysis results, with difficult deglutition, dysarthria, paralyses of the palate and pharynx, and disturbances of phonation. As rarer symptoms may be mentioned albuminuria, polyuria, mellituria, and fever. Tumors of the Cerebral Peduncle and Interpeduncular Space.—The characteristic symptom of this locality is an alternate paralysis in almost all cases (eighty per cent.), The limbs, the facial, and the hypoglossal nerve are paralyzed on the same side, the side opposite the tumor, The motor-oculi nerve is paralyzed by direct pressure on its trunk as it emerges into the interpeduncular space, and therefore on the same side as the tumor. The paraly- sis is usually total, so that there is unilateral dilatation of the pupil, ptosis from paralysis of the levator pal- pebree, and divergent strabismus from paralysis of the internal rectus. Such alternate motor paralyses may exist alone, when the tumor is limited to the pes pedun- culi; but if the lemniscus is involved, crossed sensory dis- turbance, crossed ataxia, or intention tremor from irrita- tion of the fibres of the pyramid will be added to the symptomatology. These symptoms may exist alone without motor paralysis when the tumor begins in the lemniscus. As the tumor grows larger, it crosses the in- terpeduncular space, causing bilateral oculo-motor pa- ralysis and paraplegia, often symptoms of the pseudo- bulbar paralysis. As in tumors springing from the base of the cranium, all the basal cranial nerves may ulti- mately be involved—trochlearis, abducens, trigeminus, and even facial. Vaso-motor symptoms occur when the substantia nigra is involved. Tumors of the Cerebral Cortexr.—The symptoms vary so greatly, according to the precise part of the cortex which is affected, that each part must be considered separately. Frontal Lobes.—Notwithstanding the important func- tions which doubtless pertain to the frontal lobes, a tumor in them not unfrequently remains latent. Bruns denies that psychic symptoms are particularly frequent in frontal tumors; but, according to our tables, they are present in forty-nine per cent. of the cases. One peculiar psychic symptom has been observed, namely, a tendency to crack jokes, the so-called “ Witzelsucht” of Jastro- witz. which has been already mentioned as depending on paresis of the trunk muscles, and which simulates the better known cerebellar ataxia. Tonic cramps of the muscles of the trunk and neck are sometimes noticed,— sometimes a persistent rigidity of the neck. Many symptoms are due to pressure upon neighboring parts. Pressure on the central convolutions will lead to mono- or hemiplegia. Growth downward toward the base of the brain may bring a frontal tumor into direct or in- direct contact with an optic nerve, or with the chiasma, resulting in a unilateral choked disc or unilateral nerve atrophy and blindness. Or there may be one-sided paralysis of the ocular muscles, especially the abducens; ‘ison the right side. Another characteristic symptom is the ataxia, - or a unilateral anosmia; or an exophthalmus if the tumor penetrates the orbit. To these symptoms may be added attacks of Jacksonian epilepsy; motor aphasia; cireum- scribed tenderness on percussion; lesser degree of head- ache, but greater tendency to stupor. These concomi- tant symptoms may serve to differentiate between a frontal ataxia and an ataxia due to cerebellar tumor. Central Convolutions.—These contain the centres for all the voluntary movements of the body—centres, how- ever, extending into several other areas. Thus the gyrus paracentralis; the posterior part of the first frontal con- volution; the anterior part of the superior temporal, the gyrus marginalis (trunk muscles); the foot of third frontal convolution (motor-speech centre); second frontal convolution (centre for movements of head and eyes); neighborhood of facial and hypoglossal centres (move- ments of vocal chords and jaw muscles). Tumors in this extensive motor zone, therefore, are indicated by most characteristic symptoms of localized spasms and paraly- ses which occur early in their history. Horsley and Schii- fer’s experiments on the cortex have permitted further refinements of localization: for the thumb, in the posterior part of the anterior central convolution; for the foot and toe movements, in the posterior central convolution; and on the limits between the leg and arm centres, special centres for the movements of hip and knee. The larynx and the muscles of the trunk receive a double cortical innervation, and thus a unilateral tumor will cause muscular twitchings or Jacksonian convulsions on both sides of the body. As a second consequence of the double innervation, such regions as the eyes and larynx usually escape paralysis in hemiplegia. According to the most modern view, the motor cen- tres in the central convolutions are also centres for sensi- bility, and nevertheless sensory symptoms are usually lacking in tumors of the motor zone. Local muscular spasms are, however, frequently preceded by parzesthe- Sias in the affected limbs, constituting a sensory aura. Sometimes the whole attack remains limited to the aura, constituting a sensory epilepsy. Orthisagain is replaced by a psychic equivalent, a feeling of fear or excessive anguish. When the sensory symptoms are primary, it may be inferred that the tumor occupies the posterior central convolution. The frequent absence of sensory paralyses is explained by a wider distribution of sensory mechanisms, of which a part escape injury in all but the most extensive lesions. Parietal Lobes. —The symptoms differ on the right and left sides. SIMA Sc Spring Spring. Chloride of sodium ...... 6.9675 | 6.4409 3.5430 2.2500 Chloride of potassium....| .0309 0296 0230 0805 Chloride of calcium ...... ieiets ao ih omagee 2870 Chloride of magnesium .. tiga Aree le Pickett 1.0338 Bromide of sodium....... 2150 .0169 0100 Bromide of magnesium .. Saac Soaliet \ cea 0238 Iodide of sodium......... 0005 -0014 Todide of magnesium .... oer ius eeullamaeeetres 0021 Sulphate of soda......... .0053 0048 .0183 Carbonate of soda........ 0485 1762 4558 Carbonate of lime........ 1480 | .1175 2100 | 1264 Carbonate of magnesium.| _.5262 5172 2940 8672 Carbonate of iron........ Trace. | Trace. Trace Trace. PARTELLUS seplgree Giatsic'e'cs vie sles 0044 sate 0026 PUMICE eres vleieisiein tale oieisiers oe 6 0310 «0425 0840 .0225 TeOti 7.3470 4.6407 14.6433 These springs are carbonated saline, mildly charged with carbonic acid gas. There escapes with the water of the Gas Spring a large amount of carbureted hydro- gen gas. The water of the White Sulphur Spring con- tains sulphureted hydrogen equal to about one cubic inch per gallon. The springs are situated on a level CALENDULA. MARIGOLD.—< The florets of Calendula officinalis L. (fam. Composite)” (U. 8. P.). These florets are strap-shaped, nearly half an inch long, three-toothed, hairy upon the tube, of a bright yellow color, pistillate, with a two-branched style. The odor is characteristic, the taste aromatic and bitterish. They contain a little volatile oil and an amaroid, with resin and an abundance of the bright yellow coloring matter, Calendulin, which is inactive. The drug possesses very slight aromatic- bitter properties, but is chiefly used for coloring pur- poses. It is now much less used than formerly, and will doubtless be omitted from the next edition of the Pharmacopeeia. The dose is 1 to 2 gm. (gr. xv. to Xxx.). The herb possesses similar properties, but is even weaker and contains much more mucilage. It has been used similarly, as well as for making poultices. Through an error, this, instead of the florets, was incorporated in the preceding edition of the Pharmacopceia. Henry H, Rushy. CALIFORNIA, SOUTHERN.—In this article only a brief and general account of the climate of Southern Cali- fornia wiil be given, as the principal resorts and sections will receive especial mention under their respective heads, in regular alphabetical order. Southern California is an irregular area of territory, equal in extent to England and Wales, lying between latitude 35° 40’ and 82° 30’, with a coast line of 380 miles. It is bounded on the north by the Tehachapi Mountains, which are spurs of the coast ranges and Sierra Nevada; on the east by the Colorado River; on the south by the Mexican frontier; and on the west and southwest by the Pacific Ocean. In the western portion is the southern coast range, forming the eastern boundary of the coast plain, w hich contains numerous beautiful v alleys, such as the Santa Claraand Santa Buena Ventura. This coast plain extends for 150 miles, and is from 15 to 25 miles in depth. Between the coast range and the Sierra Madre and San Bernardino ranges lies the interior plain, 200 miles in length and from 15 to 30 miles in depth. Here is the great. San Gabriel Valley, which has been called the Lombardy of America, and numerous lesser valleys. “Between the coast plain and the long interior valley, Fig. 1072.—Bay of San Diego, Southern California. plateau which extends for many miles in all directions, the country being open and well cultivated. The Grand Hotel is commodious and comfortable. The manage- ment is excellent. All modern methods for utilizing the waters are at hand, and a physician resides at the hotel during the season. There are also a number of boarding- houses and cottages on the grounds, all of which are under the controi of thecompany. The hotels are open from June to October. The Caledonia Springs are the best known of Canadian mineral springs, and are resorted to by large numbers from Canada and the United States, particularly from the South. In addition to the water consumed at the springs large quantities are bottled and sent to all parts of Canada and the United States. Beaumont Smalt. the coast range of mountains is broken, and, opposite the Los Angeles plains, entirely disappears for a space. The whole country becomes thus a great open coast-land fac- ing the south, and with the hig h Sierra for a back- eround. ”* North and east of the Sierra, or inland range, lie the Mojave and Colorado deserts. It is with the resorts on or near the coast, or with those in the interior plain, that we have especially to deal as climatic stations, such as Santa Barbara, San Diego, Coronado Beach, on the coast; or, farther inland, Riverside, Redlands, San Bernardino, and others. The soil iscomposed largely of disintegrated granite, which is sandy and porous, ‘and in many Tocali- ties there are also large patches of adobe or red clay. * “ California of the South,’ by Walter Lindley and J. P. Widney, 1888. 553 California Geysers. California, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. SAN DIEGO, LATITUDE, 32° 43’; LONG-||SANTA BARBARA, LATITUDE, 34° 28’;/|LOS ANGELES, LATITUDE, 384° 3/5 ITUDE, 117° 10’, LONGITUDE, 119° 41’, LONGITUDE, 118° 5’. Climatic Data. Jan. |April.| July. | Noy.| Winter | Year.|| Jan. |April.} July. | Nov.|Winter | Year.|| Jan. |April.| July. | Nov.|Winter | Year. Temperature— Average or normal ....| 53.6° | 57.7° | 67.1° | 58.2°| 54.5° | 60.4° || 51.2° | 60.5° | 66.8° | 56.0°/54.01°| 60.7° || 54.1° | 58.0° | 71.1° |62.0°| 58.5° | 62.0° Average daily range...| 17.8 | 14.1 | 11.6 |18.1 | 16 14.3 || 18 18 19 25 ciowje | LOL 2001.) 20:2) 28.0 aie Mean of warmest...... G1.8591/68:82 75.0.0 66: Oul enn cule neat omnes 69.2 | 62.3 «+e || 62.9 | 69.2 | 82 70.7 Mean of coldest........ 44.5 | 51.2 | 61.9 | 48.7 42.8 | 52 69.7 |53 42.8 | 49 58.9 | 46.2 Highest or maximum ..| 78 87 86 85 83 86 89 82 82 94 98.1 |86 Lowest or minimum... .| 32 39 54 33 38 i 44 40 30 39 51.2 |34.2 Humidity— Mean relative.......... 71.2% | 72.4% | 76.4% |66.4%| 70.9% | 72.9% || 71% | 67% | 72% 64% 73% || 62.9% | 70.1% | 69.4% |57.3%| 63.6% | 66.6% Precipitation— ane in inches ..... 1.85} 0.68] 0.02) 0.70) 6.04] 9.49 || 3.7 1.4 LG WALT | ATi a.9 1.3 .95| 8.65} 18 Wind— y Prevailing direction ...| N.E.| W. W. |N.W.| N.E. | W. Wie N.E.| W. W.. IN. Bal ON Benen vy Average hourly velocity in Miles Seen eset 5.1 6.6 6.3 5.1] 5.4 5.9 4.3 5.3 5.1 3 4.6 || 5.5 5.4 4.9 4.9] 5.4 5.1 Weather— Average number of clear days.:. nse. scn 11.3 | 10.2 8.2 | 13.5 | 33.5 | 122.7 || 24 16 27 13 231 17.5 |10.2 | 10.4 | 18.8 171.3 Average number of fair OAYSick cee vateeas tices D127 419) 6S 10 ease abo 6 3 9 63 8.5 | 12.5 | 19.7 9.3] 26.6 | 144.8 Average number of clear and fair days...| 22.5 | 22.1 | 24.8 | 23.5 | 67.2 | 277.8 || 25 22 30 22 294 26 22.7 | 30.1 | 28.1) 74.5 | 316.1 The main features of the climate of Southern California are warmth, equability, a large amount of sunshine and a small amount of annual rainfall. “Taken as a whole,” says Professor Hilgard, “Southern California corresponds in its climatic features and adaptation to the Mediterra- nean region of Europe and Africa; a grand Riviera with a partial background of the desert as well, where the date palm and ostrich finda congenial home, and alluvial plains equalling in riches the famed delta of the Nile.” “Warm winters, comfortably cool summers, very low rainfall, and rainfall so distributed as to divide the year into a dry and aso-called rainy season, almost unparalleled preponderance of cloudless weather, and (in consequence of the low latitude) a long duration of the daily sunshine in winter—all these are characteristic of every portion of Southern California. In comparative humidity of the atmosphere lies the chief difference between its coast stations and those lying at a greater or less distance from its coast line” (Huntington Richards). “The warmth and equability of this climate depends,” says Dr. C. F. Williams,* “upon three factors: its south- ern latitude, its protection by the various mountain ranges from cold, northerly or easterly winds, and the influence of the Pacific, and especially the warm Kuro Siwo, or Black Japan current, which washes the shores of the Western States.” There exists a certain misapprehension regarding the matter of dryness of this climate. For example, as good an authority as Lindsay refers to it as “intensely dry.” Williams calls ita “dry, warm climate,” and Remodino remarks that “every term in the meteorological vocabu- lary relative to moisture and dryness has been conscien- tiously applied to the region.” The fact is, that the coast districts, like all other coast resorts, exhibit the fea- tures of a marine climate, one of which is a large amount of moisture, and upon this fact, as we know, depend the coolness and equability characteristic of such a cli- mate. If one would find real dryness he must, as Solly says, seek it beyond the mountains in the desert country. If, however, “he seeks more days of sunshine and opportu- nities for outdoor life, with a more equable temperature and an average humidity a little greater than that of New York or Boston, he can find what he desires at Santa Barbara or San Diego.” Even as far inland as Riverside, more than 50 miles from the coast, the humid- ity is appreciably greater than at Aiken, for example, and very considerably greater than at most of the Colo- rado, New Mexico, and Arizona resorts. Still further, one must bear in mind the fact, as Solly says, “that, in spite of the great amount of sunshine during the day in California, the foggy and damp nights and mornings *** Aero-Therapeutics,”’ 1894. 504 take up a great part of the twenty-four hours.” This. authority notes the following observation made by him- self at Redlands: “On one occasion when at 4:30 P.M. the relative humidity, as indicated by the hygrometer, was fifty-five per cent., at 6 p.m. it had increased to eighty per cent.” ““The difference between noonday and mid- night temperature,” says Kate Sanborn,* “between sun and shade, is something to be learned and guarded against.” RIVERSIDE, 60 MILES FROM THE Coast, 850 FEET ABOVE SEA LEVEL. Jan April July Noy. Year. Mean monthly temp.. 53.1° 61.2° 77.0° 62.2° | 62.0° Maximum temp...... 78.2 89.2 101.2 89.2 Minimum temp ...... 32.7 39.2 60.5 39.5 Relative humidity.... 67% 1 56% 2 63% 3 76%4 | 67% Precipitation— Average in inches 3.27 1.43 1.35 | 10 Wind— Prevailing direction aun. Siete S. W. W. Weather— Average number of (1890) clear Gays.tacne.: 16 20 29 15 208 Average number of Tair: Gays. ese. s 105 Average number of cloudy days...... 14 9 1 10 52 From July, 1885, to July, 1886, there were 280 absolutely clear days, and 38 days of rain or showers. 1¥For the spring of 1888. 2Summer of 1888. 4 Winter of 1888. 3 Autumn of 1888. The accompanying tables of climatic data of San Diego, Santa Barbara, Los Angeles, and Riverside exhibit, so far as such statistics can, some of the principal cli- matic features of this region. As there isno government. weather station either at Santa Barbara or at Riverside, the figures for these places must be considered as only approximately correct. A general similarity will be noted in the climates of all these places. As one goes inland the relative humidity is seen to lessen. The num- ber of fair and clear days is very large, the precipitation very small, the prevailing winds are from the west, and there is no great wind velocity. At Riverside, a distance of 50 miles or more from the coast, the maximum tem- perature, especially in summer, is seen to increase. A peculiarity of this climate, not indicated in climatic charts, is the great difference between the character of the atmosphere during the day and during the night. At night the humidity is greatly increased, an example of which has already been noted in the case of Redlands. This increase of moisture by night renders the air chilly *** A Truthful Woman in Southern California,” 1895, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. z California, California Geysers, and raw, and in many cases would prevent the free ad- mission of night air into the sleeping-rooms. Even dur- ing the day this chilliness is experienced in passing from the sunshine into the shade, and when the wind blows. Another peculiarity is the frequent night fog, present not only on the coast, but extending many miles up the valleys. These fogs, which are most prevalent during the spring and summer, appear about nightfall and dis- appear during the early forenoon. Occasionally they persist during a part or the whole of the day. The an- nual mean average number of foggy nights at Los An- geles, for thirteen years, was 57. In 1891 there were 22 fogs in San Diego, 12 in 1893, and 26in 1894. At Santa Barbara there were 73 fogs in 1894. The rainfall, which is small in any event, except on the highest summits, occurs in the winter, which is the rainy season. This rainy season, however, varies very greatly from year to year. Sometimes the rain is delayed for weeks, and then it may rain continuously for days. One cannot predict from the annual average precipitation what the rainfall will be for any single year. For in- stance, Los Angeles has a normal precipitation of 18 inches, but in 1881 it was 5.6 inches, and in 1884, 40.5 inches. The normal of San Diego is 10 inches, but it has had a minimum of 3.71 inches and a maximum of 25.97 inches. The heaviest rainfall occurs in the months of December, January, and February. Even January, how- ever, may be a very dry month. In the desert regions there is almost no rain. Thus, for instance, at Indio the annual average for nine years was 2.32 inches. It is to be remembered, as Solly points out, that even in the rainy season the monthly rainfall is not usually more than the normal monthly rainfall for Eastern cities, and there are longer periods of fine weather. “The welcome rains,” he continues, “bring a vivid green to the brown valleys and hills, and the beautiful ‘ procession of flow- ers,’ Which continues from December to May, enraptures Eastern visitors.” Regarding the winds there is one point which the tables do not show, and which, as Widney says, most impresses the observer in his study of this meteorological factor, and that is, their regularity. One can be assured that at certain seasons of the year the wind will blow from a certain quarter, and rise atacertain timeeach day. Fur- ther, he knows that if the wind blows from a certain quarter, certain climatic conditions will follow: if it blows from one direction a moist atmosphere and rain will result; if from another, a dry atmosphere, cold in winter, hot in summer; if from still another, there re- sults clear, cool weather with moderate moisture. Much has been written about the great variety of cli- mate to be found in Southern California. For instance, Dr. Edwards writes* thus: “ Within a few hours from any given point one may obtain the climate to his liking.” Such sweeping statements are manifestly misleading, for where in any inhabitable locality in Southern California can be found the cool, dry air furnished in the elevated plains of Arizona, New Mexico, or Colorado, at such re- sorts as Tucson, Santa Fé, and Colorado Springs? In addition to the favorable climatic conditions of this marvellous section of country, there is the fascinating charm of beautiful and diversified scenery—sea coast and mountain—with varied and luxuriant vegetation. A great variety of fruits of both tropical and temperate regions are produced here: oranges, lemons, grapes, figs, olives, guavas, piheapples, pears, peaches, and straw- berries all the year round. Riverside has its famous Magnolia Avenue and orange groves; Sierra Madre its vineyards; Santa Monica its ostrich farm; and San Diego its beautiful Coronado Beach, which Charles Dudley Warner calls, in “Our Italy,” “An unique corner of the earth.” The temperature of the sea water is 60° F. or more throughout the year, so that one can enjoy sea bathing at any time of year. There are also abundant opportunities for hunting, fishing, camping, riding, and almost every kind of outdoor diversion, If we consider *** Two Health Seekers in Southern California,” 1897. all this, and the fact of an almost continuous sunshine, we can understand how outdoor life becomes a delight hardly imaginable until realized. Here, also, one cannot only take the open-air treat- ment, but, while doing so, can, if strength permits, oc. cupy himself in making a new home, and in light and pleasing work in garden and vineyard. As Dr. Richards says: “Southern California is not only a good winter resi- dence, but a health-giving and health-restoring home for residence all the year round.” Formerly—and to a large extent at the present time— Southern California was considered one of the most favor- able resorts in this country for pulmonary tuberculosis, and probably more invalids suffering from this disease frequented this region than any other class. Moreover, no discrimination appears to have been made regarding the stage or condition of the pulmonary trouble suitable for this climate. In the writer’s opinion, this will not be so much the case in the future, since experience is prov- ing more and more conclusively every day that the sana- torium treatment of consumption is affording the best results, and that the situation of the sanatorium, climat- ically considered, does not make so much difference, provided pure air, a dry soil, freedom from high winds, and a reasonable amount of sunshine are assured. Almost every State can offer these simple climatic conditions, and hence can have its own sanatorium, This plan, moreover, possesses the further advantage, so much emphasized by the German phthisio-therapeutists, that the consumptive is treated under a climate like that in which, if cured, he will continue to live. There are no published statistics known to the writer of the results of treatment of consumption by the South- ern California climate, so that no comparison is possible with the results of other resorts and of sanatorium treat- ment. That this climate offers excellent opportunities for the open-air treatment of phthisis no one will deny, but that there is any striking advantage in it over that of many other resorts there are no statistics at hand to prove. In the writer’s opinion, Southern California, in the future, will be visited not so exclusively by consump- tives as heretofore, but by the large class of invalids re- quiring a mild, equable, sunny climate, with ample op- portunity for outdoor life and diversion; such as the feeble from age or inherited weakness, convalescents from various acute diseases, those suffering from malaria, catarrhal affections, chronic bronchitis, renal and cardiac diseases, scrofulous children, and those individuals who are in the quiescent state of pulmonary tuberculosis without pyrexia. Finally, to this list must be added that increasingly large number of persons who desire to escape the inclemency of a Northern winter. The conditions for which this climate is unfavorable or doubtful are phthisis with acute symptoms, certain dis- eases of the nervous system, laryngeal phthisis, eczema, asthma, and rheumatism. There has been much exaggerated and immoderate writing on the climate of Southern California, not infre- quently from selfish and commercial reasons, as also from superficial and inadequate knowledge. One physician writes of San Diego that it presents “all the factors req- uisite ina perfect climate.” Another, writing of Pasa- dena, says that it is “the greatest all-the-year-round- health resort in the world,” aud so on. Such wild statements, generally made without any accompanying meteorological data, seem quite unneces- sary in regard to a climate which in fact and truth pos- sesses so many points of excellence as does that of Southern California. Edward O. Otis. CALIFORNIA GEYSERS, THE. — Sonoma County, California. Hotel and cottages. This marvellous region is located in the northeastern part of Sonoma County, about 100 miles north of San Francisco, 16 miles from Cloverdale, and 26 miles from Calistoga. Formerly tour- ists rode on horseback for many miles to visit this realm of fumaroles and solfataras, which is situated about 1,700 feet above the sea level; but, thanks to the push and 555 California Poppy. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Calorimetry. ANALYSIS OF WATERS FROM SEVERAL SPRINGS AT THE CALIFORNIA GEYSERS. , a aps | & B eps 3 me) we | Pm) a MICOS mleo + & 2 hn so go Bo aoe, Ba ° BSo "Sto Ss oo $3 wo ES go nee awe | SEX) ES ES |SSES|(ae8| ESS | SSS | Ses (SEwSlaess| $2 Contents per United States Gallon, | B25 | SER | Br mo, |b | Sao) Beas, | Cas aan Pinks eogr| Fk Expressed in Grains. dae) Sse | oe ga late Qesee! age 8a] cae Besa 2ogda saat S75 |FSe| Sf | Be [sseclgo | PES | See | S78 asesisess| (28 a B| *8 | <& jFo. c's) efelafe.e\elo.e)sisieies 76 Magnesium sulphate........+.+-.s05+ mdalecsclt Beceninns 1.16 Magnesium CHIOTICE.......ccccecsccerescscesevevecees 40 MANCINI CHIGTIGE. . 2.050 cccccc cles cccreccevcvevccvece 96 Calcium sulphate...........cccccscccvcs ASOOAOC AE CCT 1.25 FELTOUS PPOLOKIGE, ....25.0ccccccccccrcecccnersssencss 45 IMPANIDANCSE ss obeys viois oo vine vie sicinle vice nisieivin vin vie-0 se .010 eens Trace BAUER otto kcistrisininls Har Wasleiieise sirienmewnsneeis.e 6 ot ATL rad cine a Cotesia’ ounia.sioie svi ei'tls Wal aus| ortlercls)e.e.s\0© oie 3.61 OTAANIC MAtter........cecvccevecsecssscseccveccscrers Traces. MS AITHO MUN core iaians circle aiainviclslc nits o'o aihie'elee uv ee cessive 41.98 Sulphureted hydrogen Zas..........sseeeseeveveees 6.30 cu. in. Temperature Of Water ........2ceeeeecsceeenenene 121.6° F. The springs have gained considerable celebrity in ob- stinate cases of syphilitic contamination, rheumatism, ete. James K,. Crook. CALLOSITAS.—( Callus, Hardened Skin).—SyYNoNnymMs. —Callosity; Tyloma; Tylosis; Callus; Keratoma; (F7.) Durillon. DeEFINITION.—A circumscribed thickening and weld- ing of the horny layer produced by intermittent friction or pressure. Jallosities are congenital or acquired. The congenital callosities, however, are now usually discussed separately under the heading of Keratodermia or Tylosis Palme et Plante. The latter are diffuse or circumscribed kera- tomata, usually symmetrically distributed over the palms or soles, or over both, springing from an apparently nor- mal skin or surrounded by a red areola. Arsenic from prolonged use often causes a similar condition. Peculiar symmetrical horny hypertrophies are some- times associated with certain neuroses or unknown con- stitutional conditions; these are often preceded by mild inflammatory symptoms. The so-called syphilitic kerato- dermias should probably be placed with the latter class. The term callosity is more properly applied to the acquired form, which is essentially a result of external irritation by friction, by ¢ntermittent pressure, or rarely by chemicals. Continuous pressure or friction causes active inflammatory reaction, either vesiculation, or pustulation, or slough- ing. The result of this milder trauma is best seen upon the hands of mechanics, oarsmen, wood-choppers, and those whose occupations necessitate this irritation, as yellowish or yellowish-brown, circumscribed, round, or irregularly shaped flat or raised patches of thickened skin that are hard and resistant to the touch. They occur usually over the bony prominences or burs, and spring from apparently normal skin. Callosities may occur upon any portion of the body subjected to the exciting factor. The feet, next to the hands, are most frequently affected, due to walking bare- foot or to badly fitting shoes. This thickening of the horny cells is an effort of nature to protect the more delicate underlying structures. His- tologically there is probably no actual increase in the pro- duction of epithelial cells but a “welding” (Unna) to- gether of the pre-existing horny cells by the friction, into a homogeneous horny mass; thus the cells normally thrown off are retained, producing an apparent increase and an actual thickening. Except in those cases in which the condition results from a more violent trauma, no marked inflammatory symptoms, aside from a slight dilatation of the vessels, are seen. The acquired callosities can be differentiated from the keratodermias by the history and symmetry of the latter, though it must be remembered that in those who are particularly susceptible, very little friction may produce a marked callus. The syphilitic conditions of the palmsand soles usually begin in the centre and not over the bony prominences, spread peripherally, and at some points the horny layer is often split up or undermined. The treatment of callosities is first to remove the cause, whatever that may be. To soften and remove the thick- ened horny layer salicylic acid is the remedy par excellence. It can be used in form of a plaster (10 to 20 per cent.) or in flexible collodion (3 ss.-3i.). Either should beapplied for several days, when the affected part is immersed in very hot water for several minutes and the dead, macerated cells removed by gently scraping with a curette or dull knife blade. This procedure is repeated as often as necessary until the skin is reduced to its normal thickness, when a mild tar application will effectually complete the cure. William A. Hardaway. CALORIMETRY (L. calor, heat + Gr. pétpov, meas- ure) is the name applied to the process of measuring the heat given off from any body or substance; and a calo- rimeter is an instrument for making such measurement. Animal calorimetry is determining the heat produced 557 Calorimetry. Calorimetry. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. and the heat given off by an animal. This is accom- plished either by indirect or by direct calorimetry, each of which will be described in its proper place. A respi- ration calorimeter is one which is so arranged as to allow the inspired and the expired air to be analyzed at the same time that direct calorimetric observations are made. The unit of measure for heat in calorimetry is the calo- rie.* This is the amount of heat required to raise 1 gm. of distilled water 1° C.+ In work involving small amounts of heat this is com- monly used, and is often spoken of as a small calorie. Another unit, often called simply “calorie,” is the amount of heat required to raise 1 kgm. of water 1° C. This is called a large calorie (or sometimes a great calorie) to distinguish it from the small calorie. It is used when larger amounts of heat are to be measured. One large calorie =1,000 small calories. When the term “calorie” is used in connection with physiological experiments, the large calorie is generally meant. It will be so used in the present article. Other heat units in terms of different thermometer scales and different quantities of water were formerly employed in calorimetry, but their use is now being fast given upin favor of the calorie or large calorie —a change which is highly desirable for the sake of uni- formity. In engineering the B. T. U. (British thermal unit) is still widely employed even in papers of unques- tioned scientific standing. Its use in physiology was, for the most part, abandoned a decade or more ago. In physics and in chemistry calorimeters are mostly used for determining the specific heats of different sub- stances, for determining the heat of various combustions, and for determining the latent heat of fusion and of vapor- ization. It is not within the scope of the present article to discuss these methods or the instruments involved. In the sciences more closely allied to medicine, calorim- etry is used to study the phenomena of animal heat and its regulation in the healthy body—physiology; to study the same in fever—pathology; and to study the effect of drugs and poisons which influence body temperature— experimental pharmacology. The classic researches with the calorimeter in these fields will be discussed in the respective sections of this article, which for convenience of reference will be divided as follows: § 1. Introductory and historical. $2. Indirect calorimetry. 3. Direct calorimetry. 4. Description of calorimeters employed in classical i 5 MUTT dical researches. . Calorimetry in physiology. 3 6. Calorimetry in pathology. § 7. Calorimetry in experimental pharmacology. $1. InrRopucToRY AND HisTorrcAL.—Our modern conception of animal heat, viz., that it is produced by the slow oxidation of combustible materials in the body, first became possible with the establishment of our pres- ent theory of combustion, which dates back to the last quarter of the eighteenth century, and is dependent chiefly upon the brilliant researches and conclusions of Lavoisier (1772-94). Prior to that epoch, there was a perfect chaos of speculative theories regarding animal heat. Haller taught that this heat was produced by the friction of the blood in the heart and in the vessels; that every heart beat put the tissues on a stretch, that be- tween the heart beats they rebounded by their own elas- ticity, and all these motions produced heat by friction. Summing up he says: “ De cordis primo insito calore nulla On m AW 1A a, *Tt is interesting to note that among physicists and chemists one sometimes meets the spelling calory and the pronunciation caléry or ca’/lory. Among physiologists the original spelling calorie is re- tained (this statement is made after consulting all the available text- books of physiology), as is also the pronunciation caloree’ in conformity with the spelling and older pronunciation. Lexicographers seem to prefer the spelling calory, but give both calory and calorie as cor- rect. + Since the specific heat of water varies at different temperatures, this would be more accurately stated as the amount of heat required to raise 1 gm. of water from 15° C. to 16°C. See Berthelot, ** Thermo- chimie,’’ Paris, 1897, vol. ii., p. 5. ¢ When very minute quantities of heat are to be measured, the micro-calorie is sometimes used. A micro-calorie is .001 small calorie. 598 dubitatio superest.” Van Helmont attributed animal heat to a vital spirit. Descartes ascribed it to a fermentation of the blood in the cavities of the heart. Hamberger held that the heat of the body was comparable to the heat of adunghill. All these theories had their followers at the time the combustion theory entered the field—the theory of Haller being, probably, the dominant one. Animal heat soon came in for its share of investigation in connection with the general question of the origin of heat which was occupying the attention of investigators in England and in France at the epoch referred to. The first calorimetric researches on animals were made by Crawford in Edinburgh, and an account of them was published (1779) in a pamphlet entitled “Experiments and Observations on Animal Heat and the Inflammation of Combustible Bodies, Being an Attempt to Resolve These Phenomena into a General Law of Nature.” In this work Crawford clearly secures for himself and for England the priority in calorimetric observations on ani- mal heat, and the title of his pamphlet, as well as the matter it contains, leaves no doubt as to his position in ascribing animal heat to an oxidation of combustible sub- stances in the body. Crawford’s work has not received the recognition it deserves, and, even in English books, one occasionally sees the statement that Lavoisier was the first to use the calorimeter in experiments on animal heat. Lavoisier* had already, in 1777, from his analyses of expired air, published the fact that in the lungs the air lost oxygen and took up carbon dioxide; but his calorimetric observa- tions were first published + in conjunction with Laplace in ne year following the appearance of Crawford’s pam- . philet. Unfortunately, Crawford used the nomenclature of the old phiogiston theory to which English scientists still clung, but he measured the heat given off by guinea-pigs, and he also analyzed the air they breathed during the experiment, and his conclusions, translated into the lan- guage of modern chemistry, may fairly be given as fol- lows: Both CO, and H,O are given off by the animal from its lungs. The blood brings back from the capillaries a combustible material for which the oxygen has a great affinity. Theoxygen unites with this and produces heat which the blood distributes through the body. The heat is produced in the process by which the O is transformed into CO, or H,O. “Animal heat seems to depend upon a process similar toa chemical elective attraction.” Con- sidering that the whole theory of chemical affinity was then in its infancy, one can hardly expect a more defi- nite statement than this from a pioneer series of experi- ments. It will be seen that Crawford places the seat of com- bustion in the blood in the lungs. In this he takesa view expressed by Lavoisier, two years before, although Lavoisier, contrary to the way he is generally quoted, clearly states the possibility that there may be only a gaseous exchange in the lungs, the true oxidation taking place farther back—a position now universally held to be the correct one. § 2. InpDrREcT CALORIMETRY.—“ Indirect calorimetry ” is the name given to the method by which the heat pro- duced and the heat given off from the body are not meas- ured directly, but are calculated from the amount of oxy- gen used, and the amount of oxidized waste products given off from the body during a given period taken in connection with the body temperature. This method yields accurate results when the experiments are contin- ued uninterruptedly for a considerable time—say twenty- four hours—and when cognizance is taken of the com- position of the ingesta and of ali the waste products thrown off by the lungs, skin, kidneys, and intestines, and the temperature of the body is also carefully recorded. In many experiments the observers have considered only part of the waste products, and the experiments have been of short duration—one hour or less. While such *** Mem. de l’Acad. des Sciences,” 1777, p. 183. + Op. cit., 1780, p. 355. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Calorimetry, Calorimetry, investigations may throw light on certain isolated points in connection with the chemical changes in the body, it must be said that any conclusions drawn from them, applying generally to the heat phenomena of the animal, are untrustworthy. This becomes apparent when we consider the nature of the chemical changes productive of heat which go on in the body. The greatest amount of heat made in the body is pro- duced by the oxidation of food, which is prepared for absorption by the digestion processes and then carried by the blood to the lymph which bathes the cells of the dif- ferent tissues. These living cells then slowly burn the combustible parts of the food, and throw the waste prod- ucts back into the lymph surrounding them, from which the said waste products are taken up by the blood and carried to different organs for removal—the excreting organ depending on the character of the waste. The food which is thus burned consists mostly of carbon, hydrogen, and nitrogen, witha certain amount of oxygen, but not enough to cause its complete combustion, so that to burn it, as is done in the cells, requires the use of a considerable quantity of the oxygen which we breathe. It must not be forgotten, however, that the oxygen in the food itself is just as potent as the oxygen we breathe for forming oxidized waste products. So it is clear that unless we know how much oxygen the food contains we cannot use the oxygen taken up in the lungs as an accu- rate measure of oxidation. Again, it is a well-known law in chemistry that when a highly complex molecule breaks down into more stable ones, there is a certain amount of energy liberated, and this energy is apt to take the form of heat. Now the food contains a large number of these highly complex molecules which break down into simpler ones and give rise to heat. The oxygen in the food is in different com- bination in different kinds of food, and the same oxidized end-product of the breaking down of one food may rep- resent a very different amount of heat from that which it represents inanother. This hasadirect bearing on the “heat equivalent ” of different food-stuffs. From the above it must be seen that a determination of part or even all the oxidized waste products will not give satisfactory data from which to calculate the heat pro- duced in the body, if the waste products alone are taken into consideration. Some experiments have been made in which calcula- tions of the heat produced have been made only from the CO, excreted. It is true that of all the elements of the food whose oxidation gives rise to heat, carbon is the most important, and it is also true that CO, is the chief waste product of such oxidation. It must further be granted that the amount of CO, given off by the lungs forms a rough and general index to the total amount of oxidation in the body, but this method is unreliable as a quantitative measure of heat produced, chiefly for the following reasons: (a) There is always more or less carbon in food which is not oxidized all the way down to COs, but stops at intermediate stages. The amount of carbon thus incom- pletely oxidized varies under different conditions which are not easy to control or to recognize. This partial oxidation gives rise to heat, and there is no CO, to show for it. (b) The oxidation of the hydrogen in food gives H.0 as its end product. The amount of heat thus produced is considerable, and there is no CO, to show for it. (ec) The amount of CO, thrown off by the lungs de- pends toa large degree upon the depth of respiration, owing to changes in the partial pressure of CO: in the pulmonary alveoli. With shallow respiration an animal can store up a large quantity of CO, in the blood, and give this off if the respiration becomes deeper, so that for experiments of short duration a very considerable error may be introduced simply by the animal changing the depth of its breathing. (d) The condition of an animal, with regard to food, has a profound influence on both the heat produced and the CO, excreted, but they do not vary quantitatively together. Thisis shown by the following table compiled by Rosenthal * from the experiments of Senator and Lie- bermeister: CALORIES OF HEAT PRODUCED PER HOUR. Animal in Senator’s experiments. Measured by Calculated calorimeter. from COg. DOG As TOSI Oh ve trerscncieicie cleierers'e a clala olaversis 12.6 11.2 STALVIN Gs ccievocvee cecaieecale Swe steve te 10.9 10.24 during digestion .......... Actvern 18.9 16.0 Dog By fasting so ian cee vetie vecie cei cere 16.5 14.1 « during digestions. . ins ecc esc eece 19.4 15.4 DOSIO. Tasting ensuecclcnemeniecite: dentine 16.9 10.24 SIALUINS ae aineiteirsleteciseaennnn cr ont 15.3 9.6 during digestion oe riers. oe ens 22.0 12.2 It may be seen at a glance that the difference between the amount of heat measured directly by the calorimeter and the same value calculated from the CO, is consider- able, and that this difference varies with the food. The figures in the table are for one hour only, so that the error for a day might be twenty-four times ss great. Indirect calorimetry becomes accurate only when a careful analysis is made and the temperature recorded of everything (food, drink, air, moisture, etc.) which enters the body (ingesta); and the same is done for everything which leaves the body (egesta). The difference between the potential energy of the ingesta and of the egesta will represent the energy which the body availed itself of, and temperature records of the body will show how much of this has taken the form of heat. Such observations are excessively laborious—far more so than direct calo- rimetry. When made in connection with direct calorim- etry, however, they are exceedingly valuable, and to such experiments we owe one of the most important discoveries in modern science, viz.: that the human body obeys the law of the conservation of energy just like an inanimate machine—or, in other words, the fundamental laws of physics and chemistry dominate vital phenomena with all the rigor that they exercise in the inorganic world.+ Nearly all experimenters in the field of indirect calo- rimetry have employed modifications of the apparatus used by Regnault and Reiset,t or by Voit,$ in the classi- cal researches of these authors. For an excellent résumé and criticism of this work, with references to original papers, the reader is referred to an article by Zuntz on “ Respiratory Exchanges ” in Hermann’s “ Handbuch der Physiologie,” Leipsic, 1880, vol. iv., part 2, pp. 118-129. § 3. Direct CALoRIMETRY.—Direct calorimetry con- sists in placing the body emitting heat in an appropriate apparatus (calorimeter) which will measure the amount of heat given off. Two widely different classes of observations in the field of calorimetry are of interest tous inmedicine. The one relates to the heat equivalent of foods, or, in other words, to determining the value of the different food-stuffs as energy-producers in the body; the other relates to the study of the animal body itself by means of the calorim- eter. ; Each class of researches demands different methods and different instruments. Those of the former class will be briefly touched upon here, while those of the latter will! be more fully described. The older method of determining the heat equivalent * Rosenthal, *‘ Hermann’s Handbuch der Physiologie,” 1880, vol. iy., part ii., p. 374. + To be strictly exact, it must be said that the experiments in ques- tion have come up to ninety-nine per cent. of absolute accuracy. Considering the complexity of the experiments and the probable error involved, this is sufficiently close to warrant the above statement. For a fuller discussion of this interesting question the reader is referred to Rubner, “ Calorimetrische Methodik,”’ Marburg, 1891; Rubner, “Die Quelle der thierischen Wiarme,”’ Zeitschrift fiir Biologie, 1893; Rosen- thal, *‘Calorimetrische Untersuchungen,” Arch. fiir Physiologie, 1894 and 1897; Atwater and Rosa, ‘“‘A Respiration Calorimeter,” etc., ** Re- port of Storrs (Connecticut) Experiment Station,’’ 1897; and Atwater and Rosa, and Rosa, * Physical Review,” 1899 and 1900. +t Regnault and Reiset, Ann. de chim. et de phys., 1849, (3), xxvi. § Voit, Zeitsch. f. Biol., xiv., p. 122. 559 Calorimetry. Calorimetry. of a given food was to dry it carefully and then mix a known quantity of it with some chemical which would furnish oxygen, such as nitre or a mixture of potassium chlorate and manganese dioxide. This made a sort of gunpowder, which was detonated in a closed vessel sur- rounded by water, and the heat given off was measured by the rise in temperature of the water. An improved method, suggested by Frankland, was first practically applied by Berthelot in a special calo- rimeter which he devised. This is known as the bomb calorimeter, and is made so as to contain the food to be in- vestigated, with oxygen at a very high pressure (seven to twenty-five atmospheres). The food isignited by means of a platinum spiral heated white hot by an electric current. Berthelot found that in such an atmosphere the food was. completely oxidized. The bomb is immersed in water, and the heat given off is estimated from the rise in tem- perature of the water. There are many forms of calo- rimeters used for such determinations, but one of the two principles here outlined is at the bottom of all of them. These methods give accurate and valuable results. They are applied not only to studying the heat equiva- lent of foods, but are also used to determine the heat equivalent of partially oxidized waste products from the body, such as urea. It must not be forgotten that we utilize only part of the potential energy of many of our foods, so that to rate the value of different foods as di- rectly proportional to the figures in tables giving their heat equivalents would be a grave error. We are suffi- ciently acquainted with the metabolism of most of them to make a fair estimate of their true value as energy lib- erators in the body, but sn adequate discussion of that question would be too voluminous to be attempted here. Turning our attention now to the subject of direct calorimetric observations on animals, we may describe the process as follows: An animal is placed in one of the forms of calorimeter to be described in § 4, and the heat given off from the animal is determined in calories. This is known as the heat dissipated. If the temperature of the animal is the same on entering and on leaving the calorimeter, the heat produced must just equal the heat dissipated, for the animal brings out with his body just as much heat as he took in, and the heat dissipated while in the calorimeter must be exactly equal to what was produced there. If the temperature of the animal is higher on leaving than on entering the calorimeter, it shows that in addition to the heat dissipated and recorded by the calorimeter, there was an extra amount formed sufficient to raise the temperature of so much weight of animal so many degrees. In accordance with the laws of physics this extra amount may be found by the fol- lowing formula: x=wdh. In which— x = the extra heat formed and not recorded by calo- rimeter. w = weight of animal. d = the difference in the animal’s temperature between entering and leaving the calorimeter. h = specific heat of animal’s body. The total heat produced is then found by adding the value of z to the amdunt of heat dissipated. If the temperature of the animal falls while in the calorimeter, it shows that the heat dissipated and recorded by the calorimeter represents not only the heat actually | produced by the animal while in the instrument, but also» a certain amount of heat which is represented by the cooling down of so much weight of animal through so many degrees. In this case we amount of heat found by the above formula from the amount of heat dissipated and recorded by the calorim- eter, to get the true amount of heat produced during the time of the experiment. Direct calorimetry furnishes the most reliable means of studying variations of heat production in the body, and by this method, and this method only, can we solve a number of interesting problems, notably those connected with fever. The temperature alone is a very unsafe guide. It has been shown over and over again, by direct 560 must subtract the | REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. experiment, that we may have high fever, while the ani- mal or man is producing dess heat than normal, and it has been shown, also, that certain antipyretics will lower the temperature while the production of heat in the body is far above the normal. The temperature of the body depends upon two factors, und may be influenced by either of them separately or by both together. These factors are heat production and heat dissipation. In warm-blooded animals the balance is arranged so as to keep the temperature constant. If more heat is produced, for any reason, there is a corre- sponding increase in heat dissipation so that the temper- ature remains about the same. If more heat is dissipated more heat will be produced so as to keep the balance even and the temperature constant. If the balance is disturbed, as during fever, it is clear that we cannot tell in which factor the trouble lies by such an instrument as the thermometer, which only records the balance between them. These questions will be discussed more fully in the later sections of the article, and are only introduced here to show the importance of direct calorimetry in medi- cine. Some of the objections urged against experiments of short duration in indirect calorimetry will also apply to direct calorimetry. The metabolism of the body is be- wilderingly complex, and transient commotions produced by causes beyond the observer’s perception may give results which would be totally inapplicable to calcula- tion of averages, and which multiplied by the time suffi- cient to extend them to days would lead us to serious errors (see p. 559). § 4. DESCRIPTION OF CALORIMETERS EMPLOYED IN CuiassicAL MepicaL REsEARCHES.—As the study of the heat equivalent of foods is usually taken up with chem- istry rather than with medicine, and as the field is large enough to make a monograph by itself, it is deemed ad- visable to omit here a description of the apparatus and methods employed in this line of research. Those inter- ested will find an excellent treatise on the subject in Atwater’s “ Methodsand Results of Investigations on the Chemistry and Economy of Food” (U. 8. Dept. of Agri- culture, Bulletin No. 21, 1895). The fundamental object of all calorimeters, for animals, is to register the amount of heat given off by the animal placed within them. This is done in different ways in different instruments, and the various kinds of calorim- eters may be classified, according to the means used to measure the heat, as follows: (A) Fusion (ice) calorimeters. In these the heat is made to melt some solid (usually ice), and the amount of heat is calculated from the quantity of the substance ° melted. (B) Vaporization calorimeters. In these the heat is made to volatilize a liquid, and the amount of heat is measured by the quantity of liquid volatilized. (C) Water calorimeters. In these the heat is taken up by water, and measured by different methods according to the instrument. (D) Air calorimeters. In these the heat is taken up by air and measured by different methods, according to the instrument. (#) Respiration calorimeters. Each accurate calorimeter, whatever its form, must be calibrated. This is done by producing within it known quantities of heat, approximating those it will later be used to measure, and noting how accurately (and some- times how rapidly) the calorimeter will register this heat. The known quantity of heat is usually produced by burning, within the calorimeter, a given quantity of hy- drogen, alcohol, or some pure oil, or by passing an elec- tric current of known strength through a coil of known resistance. The heat produced is calculated from the formula: B= Px Race In which H= the heat produced, I= the strength of the current in amperes, R = the resistance of the wire in ohms, and & is a constant, which, to give the value in calories per hour = .864. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Calorimetry. Calorimetry. This is the latest and most accurate method, and serves admirably to give varying amounts of heat through the range in which the calorimeter would be called on to register the heat of animals, including man. Class A: Fusion Calorimeters.—The only calorimeter of this class employed in animal calorimetry was the ice calorimeter of Lavoisier and Laplace.* It consisted of three metal cylinders, placed one within the other, with spaces between them. The animal (guinea-pig) was placed in the innermost cylinder, and the space between this and the middle cylinder was filled with ice, which was melted by the heat given off by the animal. The space between the middle cylinder and the outer cylinder was also packed with ice to prevent heat from the out- side from reaching the ice in the space next the animal cylinder. The water from the ice melted by the animal was collected and weighed and the heat calculated by multiplying this weight by the latent heat of fusion. This is a very accurate form of calorimeter, but it is not well adapted to animal experiments, as the animal is kept in surroundings of an abnormally low temperature, and this seriously affects its production and dissipation of heat. The researches of Lavoisier and Laplace are classical, in being the second to employ the calorimeter, and the first to give valuable results of extended observa- tions which were stated in terms of the modern combus- tion theory. In these experiments the animal was fur- nished with air, and the O used and the CO, given off were determined. Class B: Vaporization Calorimeters.—Calorimeters of this class were used by I. Rosenthal and by Neesen.+ I. Rosenthal + devised a calorimeter in which he used a fluid witha boiling point near that of the ordinary room temperature, ora fluid with a boiling point a few degrees below the normal temperature of the animal. The fluids which he recommendsare acetic aldehyde, CH;,CHO, with a boiling point of 21° C., and ethyl ether, (C:H;).0, with a boiling point of 34.9° C. The calorimeter consisted of an inner cylinder, in which the animal was placed, and an outer cylinder containing the liquid to be volatilized. The whole was surrounded by a water bath kept carefully at the temperature of the boiling point of the liquid in the outer cylinder. Thus no heat could either be gained or lost by the liquid in the outer cylinder except such as came from the animal in the inner cylinder. The heat from this source was all spent in volatilizing the aldehyde or the ether, and from the quantity thus volatilized the amount of heat given off by the animal could be determined. By filling the outer cylinder with ice the instrument could be used as an ice calorimetey, and thus, as Rosenthal pointed out, according to the material used the heat dissipated could be determined for temperatures of 34.9°, 21°, or 0° C. by the same apparatus. This calorimeter, as constructed, could be used only for small animals, such as mice, or for isolated organs, such as muscles. Class C: Water Calorimeters.—The water calorimeter was the first employed in animal calorimetry (see account of Crawford’s researches, § 1). From that time (1778) to the present it has been the favoriteform. After Craw- ford it was used in the classical researches on animal heat by Despretz,§ and by Dulong, || and on fever by Senator, | and by Wood. ** In its simplest form, a water calorimeter consists of a tank containing a definite amount of water into which is plunged a water-tight metal box containing the animal. ee and Laplace, “*Mémoires de l’Academie,’’ Paris, 1780, p. 369. + See Richet’s ‘* Dictionnaire de Physiologie,’ Paris, 1897, vol. ii., p. 405. The writer was unable to find a reference to Neesen’s original article. tI. Rosenthal, Arch. fiir Physiol., 1878. § Despretz, Ann. de chim. et de phys., 1824, vol. xxiv., p. 337. | Dulong, Ann. de chim. et de phys., 18438, p. 140. In 1822, the Paris Academy offered a prize for the best experimental researches on animal heat. Despretz and Dulong were competitors and Despretz won. The work of the two was contemporaneous, but Dulong’s paper Was not published until 1843, after his death. ae ‘* Untersuchungen tiber den fieberhaften Process,” Ber- , 1875. ** Wood, ‘* Smithsonian Contributions to Knowledge,” No. 357. WAI, IO ty The animal is supplied with air by tubes entering and leaving the box. The heat given off by the animal raises the temperature of the water, and, knowing the weight of the water and the increase in temperature, the amount of heat thus given off can be calculated in calories. In text-books, the calorimeter of Dulong is generally de- scribed, but in the present article the Reichert calorimeter is chosen as a type of this class. This instrument com- bines all the simplicity of the older forms with the accu- racy and convenience of modern improvements. It has been used by Reichert * in his researches on animal heat, on fever, and on drugs. The calorimeter consists of a metal box A, for the ani- mal, and a larger metal box surrounding the box A, the CT TAS A) Dy y.') ZY) Y ad ( yn ~ Ww WD WO’ = ( e KK AN SN m PT MU = SS i ( SE Fig. 1073.—Reichert’s Water Calorimeter. space between the two metal boxes being filled with water. The whole isenclosed in a wooden box, the space between the outer metal box and the wooden box being filled with shavings SH, to prevent the radiation of heat. At the right of the figure is an opening from the exterior into the box A. This is for putting in and taking out the animal. During the experiment it is closed by a wooden plug fastened with clamps to the wooden box. The tubes HN and #X are for the entrance and exit of air, and each is furnished with a thermometer as shown in the figure. Another thermometer, (7, registers the temperature of the water. Sis a stirrer to mix the water thoroughly so as to be sure that the temperature recorded is the temperature of the whole mass of water. The ar- rows show the direction of the air current through the animal box. Ott + devised a water calorimeter of sufficient size to take aman. The inner chamber, to receive the patient, was cylindrical in form, and the air, as it was drawn from this chamber, passed through a lead pipe coiled in the water and thus gave off its heat to the water. The water was slowly stirred by a mixer driven by an electric motor. D’Arsonval’s compensating calorimeter, of constant temperature, is another form of water calorimeter, al- though the principle involved in the measurement of heat is different from that of the calorimeter last de- scribed. t This instrument is shown in Fig. 1074. It consists of two cylinders, of thick copper, enclosing a space between * Reichert, University Med. Mag., 1890, vol. ii., p. 173, and “American Text-Book of Physiology,’’ 1896, p. 586. +Ott, New York Med. Journ., 1889, vol. xlix., p. 343; also Journ. Nerv. and Ment. Dis., 1890, vol. ene 348. + D’Arsonval, Arch. de Physiol., 1890, p. 612. : 561 Calorimetry. , Calorimetry. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Through this space run two spirals of metal tub- -ing like the worm of a still. These spirals are shown in cross-section in the figure. One of these spirals connects the inner chamber of the calorimeter with the outside air. ‘The air is aspirated through the calorimeter, passing in by a tube on the left, as shown by the arrow in the figure, and out, by the spiral, tothe exterior. In passing through the spiral it gives up its heat to the petroleum with which the space between the cylindersis filled. The other spiral opens, at both its ends, on the exterior. It conducts a stream of cold water which is made to flow through it. The space between the copper cylinders, enclosing the spirals, is filled with petroleum because of its mobility. When the heat of the animal warms this petroleum it ex- them. pands, and exerts pressure on the apparatus shown in the . figure to the right of the calorimeter. This is arranged to control the flow of water through the cold-water spiral. When the calorimeter is working this makes a sensitive, automatic regulator. If the temperature of the petro- leum tends to rise the pressure exerted by its expansion causes more cold water to flow, and this immediately reduces the temperature of the petroleum to the point for spiral. On the surface of the water is a float which rises as the water in the cylinder rises. This float is attached to a lever which has on its short arm a counterpoise weight for the float, while the long arm is made to write on a cylinder driven by clockwork. Since the rise of the lever is directly proportional to the amount of water flowing through the spiral, and since this is directly pro-. portional to the heat given off by the animal, it follows that the ordinates of the curve written by the lever will be directly proportional to the heat which we wish to measure. The abscissas will be in terms of time, and will be proportional to the speed of the drum. By regulating the length of the lever and the speed of the drum a curve may be obtained which can be read in terms of calories for any convenient unit of time, minutes, hours, days, etc., without further calculation. A more elaborate re- cording apparatus with electrical contacts is figured and described by D’ Arsonval (Arch. de Physiol., 1890, p. 616). The same author has described a more convenient but less accurate calorimeter based on a modification of the one just described (op. ezt., p. 620). One of the most recent, as well as one of the most elab- orate and perfect water calorimeters, is that of Atwater and Rosa.* In this calorimeter experiments, lasting sev- era! days, have been conducted on man. The principle involved is practically the same as that of D’Arsonval’s compensating calorimeter (Fig. 1074); the heat being removed by coils of pipe carrying cold water through the chamber where the man is placed. Fora full description of this instrument and methods employed, the reader is referred to the original papers. A more condensed description of the ~ apparatus is given under the head of Respira- > tion Calorimeters at the end of this section. Calorimetry by Baths. The study of heat phenomena in animals by baths has found a place in medical literature chiefly through the classical researches of Liebermeister,+ and his pupils Kernig, Hattwig, and Gildemeister. The method here employed was to place the patient in baths of different temperatures, and to calculate the production of heat from the = t0" il = —=— _ gain or loss of heat by the patient and by the water under different conditions. This pro- cedure presents certain crudities and sources of Fig. 1074.—D’Arsonval’s Compensating Calorimeter of Constant Temperature. which the instrument is set. (Fora description of this regulator in detail, see Arch. de Physiol., 1890, p. 614.) The cold water is furnished from a tank, and is made to enter the calorimeter at a known temperature. >> YZZZZ ZN (2. i litnxrcccrcctcedsuuuuQ1uunnnnNnlr ANAAAAAAAAAAAAAANAAAANANAAAAAAANAAARANAA ANS NA ASSESS ASSSNE SEES SS LLLLLLELLELLILILLULELLLLILLUALLLLULILLLLLULLLLLLLLIULLUL LIMIT INI EbEG VLA NS SSSS SSS SSS SUS SSS SSS SGT VILLA VA ZEEE a a ome ei ad era ag ms ek LLa (SR a ee \LLLSLLSLILILSLELLLELLLLTSDTSSSTSTLELELTDDELLL TELLS TTA: | 00) ASR Se SSS Se Se SE en) Meer | eee LLL WCZIZZZZLLL LLL LLL LLL LLL VILL LLL LLL HH N| || N N N N N i N Z N UZ NXAAAAAAAAAAAAAARAAAAAAAAAAN OAAAAAAAAAAAAAANAAAAANANANAANAN ANANSI SDSS N< SCALE | METER BESSSSSS LL LLUTATTLDEIOITLE 3 Beeeeecceccccccccccccccecccceleclcecceceeeccccceceeeeet Fig. 1079.—Horizontal Cross-Section of Respiration Calorimeter, 565 Calorimetry. Calorimetry. The amount of the outgoing water and its temperature are measured, thus determining the heat carried away. “ A general idea of the apparatus can be had from Figs. 1078 and 1078. Fig. 1078, froma photograph, isa general view of the principal parts of the apparatus, though the pump and aspirators used for moving, measuring, and sampling the ventilating air current and the refrigerating machine are not shown. In the centre is the large cham- ber which is surrounded by sheathing of wood. At the end of the chamber, on the right, is shown a glass door which servesalsoasa window. In the foreground, near the cen- tre and at the right, are the pipes through which the ven- tilating current of air passes. At the right of the window and just below it are the arrangements for cooling and for measuring the current of water which brings away the heat from the interior of the chamber. . At the left, in front of the large brick pillar, is a table at which an ob- server sits torecord the temperature of the interior of the apparatus and of the currents of air and water, these temperatures being measured by electrical thermometers. Behind the brick pillar is the refrigerating machine, not shown in the picture. The object of this is to cool the brine, 7.e., a solution of calcium chloride contained in a large tank in the centre foreground. The tank is sur- rounded by a wooden casing. The ventilating current of air, before it enters the chamber, is passed through copper cylinders which are immersed in brine in this tank, and thus cooled to a temperature of from —19° to —22° C., or from —2° to —8° F. At this very low tem- perature nearly all the water is removed from the air, so that it enters the chamber quite dry. Just before enter- ing, at the right of the glass door, it is warmed to the temperature of the interior of the chamber. On coming out it passes once more through copper cylinders in the cold brine, and thus the larger part of the water which has been imparted to it by the respiration of the man in- side the chamber is frozenand removed. The air pump is at the right and the aspirators are at the left of the position occupied by the camera in taking the photo- raph. en The Respiration Chamber.—The internal construction of the chamber and the arrangements for regulating the temperature are shown in horizontal section in Fig. 1079. “The chamber proper is practically an apartment with double walls of metal, the inner wall being of sheet cop- per and the outer one of zinc. The interior is 2.15 m. (7 ft.) long, 1.92 m. (6 ft. 4 in.) high, and 1.22 m. (4 ft.) wide, the corners being rounded. It thus hasa little less than 28 square feet of floor space. The cubic content is not far from 4.8 cubic metres or 175 cubic feet. The inner wall is made of large sheets of copper, the seams being soldered so that when the windows and other open- ings are closed the chamber is air tight, and the only air which enters or leaves is that of the ventilating current. Outside this copper wall is one of zinc. Between the two metal walls is an air space(A) of 7.5cm. (3 in.). In this space stands a wooden framework to which the two metal walls are securely attached. This metal chamber is the calorimeter proper. In order to protect it from the fluctuations of temperature of the room in which it stands, it is enclosed within three concentric walls of wood. Between the zinc and the innermost wooden wall is an air space (B) of 5 cm. (2 in.), between this wall and the next is a third air space (C) of 5 cm., and finally be- tween this and the outer wall is a fourth air space (D), likewise of 5cm. The wooden walls are made of matched pine covered with sheathing paper. The outer one is double with sheathing paper between. The air in the spaces A and C is ‘ dead air,’ while that in the spaces B and D can be kept in constant circulation by means of rotary fans in boxes outside. Each of the spaces B and D is continuous around the sides and over the top and bottom of the calorimeter, and each communicates with its fan box by means of one passage extending from the top of the air space to the top of its fan box, and another from the bottom of the air space to the bottom of the fan box. We may thus look upon these air spaces as shields guarding the interior space occupied by the calorimeter 5966 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. from changes in temperature without. They thus ren- der necessary aid in accomplishing a fundamental object, namely, the keeping of the temperature of the air in the space B the same as that of the interior of the chamber. When these temperatures are the same there will be no. passage of heat through the walls, either into or out of the chamber. “The outer air current (D) is used for the coarser regu- lations of temperature. In the middle of the dead air space (C) is a wall of sheathing paper intended to more effectually prevent the external temperature from affect- ing that of the calorimeter. “ The walls are provided at the right with glass doors or windows. At Ein Fig. 1079 isa cylinder of copper which ' - passes through the walls of the chamber and also through the encasing walls of wood. This cylinder, which is 15 cm. (6 in.) in diameter, serves for passing food and other materials into and out of the calorimeter chamber, and ig here called the ‘food aperture.’ It is closed at the ends by caps aand b. The outer (2) is screwed tightly to the cylinder so as to make an air-tight closure. Outside of this is a box or cover (c), made of wood and filled with cotton or other non-conducting material, the purpose being to prevent the passage of heat through E. “ Measurements of Temperature. The measurements of temperature are made in part by mercury thermometers, but mainly by electrical methods. The electrical meas- urements of temperature are made by use of either the German silver-iron thermal junctions or by resistance coils of fine copper wire. - Provision is made for connecting these with a D’Arsonval galvanometer especially con- structed for the purpose by Mr. O. 8. Blakeslee, mechan- ician of Wesleyan University. The electrical thermome- ters permit measurements of .01° C. or less. “ Temperature of Air Inside the Chamber. Inasmuch as the temperature of the air is not the same in different, parts of the chamber, and it is desirable to know the average or resultant temperature of the whole, the at- tempt is made to learn the latter by the use of a series of five electrical thermometers at places near the sides, top, and bottom. These consist of resistance coils of copper. wire connected with a slide wire Wheatstone bridge and the galvanometer outside. The measurements are so del- icate that even slight movements of the person inside, such as rising from the chair, reveal themselves to the observer outside by the immediate rise in the thermomet- ric reading. “ Regulation of Temperature of Ingoing Air. In order that the ventilating current of air shall not carry out of the chamber any more or any less heat than it brings in, the temperature must be the same when it enters as when it leaves. Accordingly the incoming air, which leaves, the brine tank at a very low temperature, is warmed, before its entrance to the chamber, to the temperature of the outgoing air. The devices for this purpose are such that the difference of temperature of the incoming and outgoing currents can be kept inside of .01° C. In actual experiments the positive and negative differences are made to counterbalance each other. “Arrangements for Preventing the Passage of Heat through the Walls of the Calorimeter. The difference be- tween the temperature of the copper wall and that of the zinc is measured by a system of thermo-electric junc- tions, in three hundred and four pairs, distributed over the sides, top, and bottom, one-half of the junctions (iron- German silver) being in close thermal contact with the copper wall and the other half (German silver-iron), with the zinc wall. The difference of temperature of the two, walls is made as small as possible by warming or cooling the air in the space B, and the positive and negative dif- ferences are made to counterbalance each other. Thus, the corresponding movements of small quantities of heat, inward and outward also counterbalance, and the cham- ber neither gains nor loses heat through the walls. “For the measurement of the differences of tempera- ture, as well as for the warming and cooling, the walls, of the calorimeter are considered as divided into four sec- tions, viz.: (1) the top; (2) the upper half of the sides or REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Calorimetry, Calorimetry, ‘upper zone’; (3) the lower half of the sides or ‘lower zone’; (4) the bottom. The systems of thermo-electric elements for heat measurements, wires for warming and of water pipes for cooling, are each divided into corre- sponding sections. “The Observer's Table. This is shown in Fig. 1078 at the left, in front of the brick pier. A shelf fastened to the pier and shown on the right of the latter, behind the table in the picture, holds the galvanometer and scale. The scale is seen in the picture at the front end of the shelf over the table. The galvanometer is at the other end of the shelf, two metres from the scale and obscured by the pier. On the table are the switches to bring the various circuits into connection with the galvanometer, and with them the Wheatstone bridges, and the banks of electric lamps for varying the heating currents. “With the aid of the devices thus briefly described an experienced operator at the observer’s table can easily control the temperature of B and make it follow the vari- ations of the interior of the chamber very closely. When the rate of generation of the heat in the chamber is rea- sonably uniform and the temperature is nearly constant, the deflection of the image on the scale at the observer’s table can usually be kept within one division of the scale, which means an average difference of temperature be- tween the copper and zinc walls of less than .01° C. In ordinary experiments the difference is generally kept within this limit and seldom reaches .05°. The differ- ences are both positive and negative, and are easily made to counterbalance each other during shorter periods and during the whole experiment. “ Measurement of the Heat Carried Out by the Water Current. The principle here employed is simple. The chamber neither gains nor loses heat by the air current nor through the walls. The current of cold water which passes through the heat absorbers inside the chamber is caused to enter ata temperature generally but little above the freezing point, and to flow out at such a rate as to absorb and carry off the heat just as fast as it is gener- ated inside theapparatus. The temperature of the water is measured as it enters and as it comes out. The mer- cury thermometers are shown at G and H in Fig. 1079. The electrical thermometer indicates the difference of temperature between the incoming and outgoing water currents by the difference of resistance of two coils of thin copper wire, of which one is in each pipe at the place of entrance or exit from the calorimeter. The dif- ference is measured by a Wheatstone’s bridge on the observer’s table. The mass of water is measured auto- matically by the apparatus shown below and at the right of the window of the respiration chamber in Fig. 1078. “From the mass of the water which has passed through the absorber in a given time, and the rise in temperature, the quantities of heat brought out are readily calculated. To this is to be added a certain amount of heat which is carried away with the water vapor produced in the ap- paratus. This is practically the difference between the water vapor in the incoming and outgoing air. From the amount of this vapor, and its latent heat at the tem- perature of exit, the amount of heat it carries out is easily computed. “ Metre Pump for Regulating, Measuring, and Sampling the Ventilating Air Current. for analysis, aspirators of 150 litres capacity were em- ployed at the outset and are still used. The measure- ments with these have been found quite accurate.* The most satisfactory arrangement we have found, and one which serves the threefold purpose of maintaining the air current, measuring its volume and delivering aliquot samples of convenient size for analyses, is an apparatus designed and made by Mr. O. S. Blakeslee, and appro- priately designated by him as a ‘metre-pump.’ The air coming from the discharge pipe escapes into the room, but by a special device the air of each fiftieth * See ‘‘ Report of the Storrs Station for 1896,” p. 91, and ** Bulletin 44 of the Office of Experiment Stations of the United States Department of Agriculture,” p. 19. For taking samples of air. stroke is diverted into a receptacle, from which it is being constantly drawn for analysis. “ Cooling Apparatus. It is desirable that the ventilating current of air shall enter the respiration chamber as dry as possible. To this end it is cooled to a temperature of —19° to —22° C. (—2° to —8° F.), by passing through copper cylinders which are immersed in brine in the tank shown in Fig. 1078. The brine is cooled by use of an ammonia refrigerating apparatus.* The airafter passing out of the cylinder is warmed before entering the cham- ber in the way described. On coming out of the cham- ber the air current is again passed through copper cylin- ders immersed in the brine, and thus practically all of the water which has been imparted to it within the chamber is removed. The same brine is used for cooling the current of water which passes through the absorbers and conveys away the heat from the chamber. “ Analyses of Air, Determinations of Carbon Dioxide and Water. The methods used for these purposes are essen- tially the same as described in the ‘ Report of the Storrs Experiment Station,’ and ‘ Bulletin 44 of the Office of Experiment Stations of the United States Department of Agriculture,’ above referred to. It will therefore suf- fice to say here that the larger part of the water is caught in the copper cylinders, immersed in the cooling brine as above described, and its amount found by weighing. The residue of the water of both the incoming and out- going air current is determined in samples by passing through U-tubes containing pumice stone and sulphuric acid. The carbonic acid is in like manner determined by passing through U-tubes containing soda lime. “In the ordinary experiments the determinations of water, carbonic acid, and heat are made for periods of six hours.” § 5. CALORIMETRY IN PuysioLocy.—Heat Centres.— In§ 3 it was pointed out that the temperature of the body depended upon the balance between two factors: heat production and heat dissipation. We know that heat dissipation is dependent chiefly upon three factors: the supply of blood to the skin, the sweat, and respiration. The more blood in the vessels of the skin the more heat will be radiated off; the more sweat formed the more heat will be lost by the temperature of the sweat and by evaporation; the more vigorous the respiration the more heat will be lost in the expired air and by evaporation in the air passages. Each of these functionsis dominated by a special centre or set of centres, the vaso-motor, the sweat, and the respiratory centre, respectively. The question has naturally arisen, How is it with heat produc- tion? We know that the nervous system controls the chemical activities of the tissues—is there a centre which dominates this control? If so, how? Are there centres which cause an increased oxidation of food with increased production of heat? Are there centres which inhibit this oxidation and thus decrease heat production? Are there specific nerves through which such centres act on the tis- sues? It is in the experimental investigations relative to these questions that the calorimeter has been most em- ployed in physiology. The method of experiment has usually been to produce a lesion of the central nervous system, or to stimulate a definite area; and to note the effect on the animal’s tem- perature, or to measure the effect on heat production and heat dissipation by direct or by indirect calorimetry. It is obviously not within our province to undertake a critical review of all the work done on a specific sub- ject, such as heat centres. Besides, our information is at present in a state more or less chaotic, as has always been the case with work of this kind on the central ner- vous system. We need only recall the confusion which existed fifteen or twenty years ago regarding experi- ments on “localization” in the cortex, of the centres of motion, and of the special senses, to get a fair idea of the present condition of our knowledge regarding heat * See description of the arrangements for cooling in ‘* Report of the Storrs Experiment Station for 1896,’ p. 92, and ‘* Bulletin 44 of the Office of Experiment Stations of the United States Department of Agriculture,’ p. 22. 567 Calorimetry. Calorimetry. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. centres. The outcome of it all has been that to-day practically no one denies the more or less definite locali- zation in the motor area, but few would still adhere to the extreme views of invariable sharp localization of a given centre at a given spot, especially in the lower ani- mals. So with the heat centres. The chief bone of con- tention has been to determine just what was injured in a given operation, rather than to doubt the accuracy of the calorimetric method, although this has not escaped criticism. Then, again, different animals were used in different experiments, and discrepant results were ob- tained in this way, just asin the case of motor localiza- tion. At present we have every gradation, from Ott,* who locates six cerebral heat centres, two in the cortex and four in the basal ganglia, to Mosso,+ who, after a full review of all previous work, and numerous experi- ments of his own, is unable to admit “that there are, in the brain, centres which preside over animal heat.” The first observer to call attention to cerebral heat centres was Tscheschichin,} who, working with Du Bois Reymond, found that lesions of the medulla in the neigh- borhood of the pons Varolii were followed by a decided rise in temperature. His work was on rabbits, and he did not use the calorimeter. This was followed by Lewizky § in 1869, and by Bruck and Giinter| in 1870, disagreeing with Tscheschichin, and by Schreiber, {[ in 1874, agreeing, for the most part, with Tscheschichin, and disagreeing with Lewizky and with Bruck and Giinter. This was the status of the question in 1880, when Wood ** published his elaborate calorimetric researches on fever. Wood found that “section of the medulla at its junction with the pons is followed by increased heat dissipation and heat production, the increased heat dissi- pation usually keeping pace with the increased produc- tion, so that the bodily temperature rises.” Wood also found (p. 148) that “destruction of the first cerebral con- volution in the dog, posterior to, and in the vicinity of, the sulcus cruciatus is followed at once by a very decided increase of heat production, while after irritation of the same nervous tract there is a decided decrease of heat production.” Mild irritation of this region has no in- fluence on blood pressure—its destruction likewise is without vaso-motor effect (p. 153); therefore it is fair to presume that this centre influences body temperature through heat production—not heat dissipation. These earlier researches of Wood were confirmed later by a joint research of Wood, Reichert, and Hare,++ and by others, who find that there are thermogenic centres which affect the production of heat independently of blood pressure. Ott,t{ Richet,§$ and Aronsohn and Sachs, ||| working simultaneously and independently, all claim to have demonstrated the presence, in the brain, of centres which cause a rise of temperature by heat production. Richet and Ott used a calorimeter, Aronsohn and Sachs used the indirect method, determining both O and COs.. This work has in the main been supported by the later calorimetric experiments of Ott [4] and of Reichert,*** and of a number of others who have not employed the calorimeter. These observers, while differing as to the exact location of centres and as to the mode of their action, do agree, for the most part, that such centres exist. Reichert, in the work just quoted, has made an important contribution to our knowledge of heat centres in the spinal cord. He ascribes more importance to them -* Ott, N. Y. Med. Journ., 1889, vol. xlix., p. 247. + Mosso, Arch. Ital. de Biol., 1890, vol. xiii., p. 459. + Tscheschichin, Arch. f. Anat. u. Physiol., 1866, pp. 169-175. § Lewizky, Arch. f. path. Anat., 1869, vol. xlvii., pp. 356-359. | Bruck and Ginter, Arch. f. d. ges. Physiol., 1870, vol. iii., pp. 578-584. 4 Schreiber, Arch. f. d. ges. Physiol., 1874, vol. viii., pp. 576-596. ** Wood, ‘‘ Smithsonian Contributions to Knowledge,” No. 357, p. 74. ++ Wood, Reichert, and Hare, Ther. Gaz., 1886, p. 678. +t Journ. of Nerv. and Ment. Dis., 1884, vol. ix., p. 141. 8§ Richet, Arch. de Physiol., 1885, vol. vi., p. 496. || Arch. f. d. ges. Physiol., 1885, vol. xxxvii., p. 232. I Ott, Journ. of Nery. and Ment. Dis., 1887-88; Ther. Gaz., 1887, p. 399; N. Y. Med. Journ., 1889, vol. xlix., p. 247. peg wet Univ. Med. Mag., 1893, vol. v., p. 406, and 1894, vol. vi., p. 303. 568 than to those located in the medulla, basal ganglia, or cortex, The only later writer who takes an iconoclastic atti- tude with regard to cerebral heat centres, and bases this opposition on experimental data, is Mosso; and he* rather leans toward a position advocated by Girard,+ who says that we cannot speak of a thermogenic centre, but of many such centres scattered in the brain and spinal cord and working together. ¢It is quite probable that, when the confusion now existing is cleared up by later investigations, this view will be found very near to the truth. Those who wish to study this question more closely are advised to consult the papers of Wood, Ott, Reichert, and Mosso, here quoted; also papers by Hale White t and Riegel. White’s paper in Guy’s Hospital Re- ports gives interesting clinical data, which he says sup- port the calorimetrical findingsof Wood. The only clin- ical evidence quoted against cerebral heat centres is a case, reported by Dana,|| of a monster in which there was no cerebrum, basal ganglia, or cerebellum, and only part of the pons—yet the temperature was normal. This would support Reichert’s theory that the cord centres were the most important. To sum up briefly our knowledge of heat regulation and body temperature, we may say that the body tem- perature depends upon the balance between heat produc- tion and heat dissipation, each of which is directly con- trolled by the nervous system. Either of these factors may vary independently of the other, in either direction, so that body temperature may vary, as in fever, as the result of a change in either factor separately or of both acting together. Centres which control heat production are located in the cortex, basal ganglia, medulla, and cord. Some of these produce an increase in metabolism with a consequent increase of heat production, while some appear to diminish metabolism. These are usually regarded as inhibitory to the centres which cause meta- bolic activity. The spinal cord contains centres which influence heat production, and these are still active after being cut off from the medulla. There is a marked co-ordination, so to speak, between the centres which control heat production and those which control heat dissipation, the two striking a bal- ance, in warm-blooded animals, which keeps the body temperature practically constant at a certain point. It will be shown, in the following section, that in fever neither of these sets of centres is completely paralyzed, but that the balance is established at a higher point. The heat-regulating mechanism is more delicate in man than in apes, as shown by the experiments of Lefevre, { _ which are also of great interest in showing the reaction of the heat regulators of patients in a cold bath. The Separation of Motor and Trophic Nerves by Calo- rimetry.—Every muscular contraction is accompanied by the production of heat. It is well known that the mus- cles are the tissues in which is produced the greatest part of the heat which maintains the body temperature. That this heat may be produced independently of muscu- lar contraction is proved by the fact that the body tem- perature remains practically constant even when the muscles are at rest, as during’ repose or sleep. The ques- tion arises, Does the same set of nerves control muscular contraction and heat production, or do we have one set (motor) controlling muscular motion and another set (trophic ?) controlling the chemical changes (metab- olism) which give rise to heat? The first calorimetric experiments to solve this problem were undertaken by Kemp.** Making use of the fact that the drug curare paralyzes only the endings of the motor nerves, while leaving the nerve fibres and the muscle cells intact, * Mosso, op. cit., p. 463. + Girard, Arch. de Physiol., 1888, pp. 326-328. ~ Hale White, Journ. of Physiol., 1890-91; Guy’s Hospital Reports, 1883-84, vol. xxvii., p. 48. § Riegel, Arch. f. d. ges. Physiol., 1872, vol. v., p. 629. . || N. Y. Med. Journ., 1889, vol. xlix., p. 248. ‘| Lefevre, Compt. rend. Soc. de Biol., 1894-95. . ** Kemp, Therap. Gaz., 1889, pp. 86 and 155. eh ‘ , REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Calorimetry, Calorimetry, Kemp studied the effect of different-sized doses of curare on dogs, and found that small doses, just sufficient to paralyze the motion of muscles, still allowed the heat- regulating mechanism to function, and the body temper- ature to be kept up to the normal oreven torise. Larger doses, he found, caused a fall of body temperature and a diminution of heat production as recorded by the calo- rimeter. His conclusion was that since the nervous sys- tem could still control heat production after paralysis of the motor nerve, either the motor-nerve endings para- lyzed by curare retained their grip on metabolism after losing it on motion, or, what was more probable, there were two kinds of nerves, the motor and the trophic; the former being paralyzed by a small dose of curare, while the latter required a larger dose to throw them out of function. Two years later Reichert,* as part of an extended research on the rise of temperature produced by cocaine and caffeine, made a number of experiments covering the same ground as Kemp. The two sets of experiments were not under exactly the same conditions, and the results were not absolutely in harmony. The main point of difference lay in the effect of large doses ofcurare. Reichert found that these sometimes produced a fall in heat production, thus agreeing with Kemp; but in other instances he found the heat production could be kept up to the normal or even increased. The observa- tions of both, however, are in thorough accord on the main point involved, viz.: that the heat-regulating mech- anism can work through nerves which still function after the motor-nerve endings are completely paralyzed. Reichert also added the interesting observation that co- caine fails to produce its characteristic effects in animals even lightly curarized, while caffeine can still produce an increase in heat production and temperature, though its effects are somewhat modified (p. 250). Mosso,+ in working with curarized dogs, found that a dose of strychnine caused a rise of temperature. He did not use a calorimeter in these experiments. Reichert t repeated these experiments and found that strychnine may produce an increase in heat production even when the animal is paralyzed by curare, which is an additional evidence for the theory that nerves, other than the motor, control metabolismin muscles. Reichert finds, however, that the rise of temperature is due more to lessened heat dissipation than to heat production. Relation of Heat Production and Heat Dissipation to Daily Variations in Temperature. — Every clinician is familiar with the daily fluctuations in body temperature, both in health and in fever. A number of observations have been made on animals and on man to see whether there is a diurnal variation in heat production. Most of these have been by the method of indirect calorimetry, and all unite in showing the profound influence of diges- tion on the heat produced. Fredericq, for example, found the maximum absorption of oxygen to be at 10 A.M. and at 2to3p.m. Vierordt, Langlois, and Ott all agree that the period of maximum heat production is about this time. Fredericq noticed that in a starving man these maxima did not occur, and Langlois found that heat production may rise thirty-five to forty per cent. after a meal. Though we may feel warmer after a meal, it is well known that there is no actual rise of tem- perature, as shown by the thermometer, whereas the evening rise and morning fall occur, in a well-fed man, whether a meal be missed or not. Carter,$ in Ott’s laboratory, undertook an investiga- tion of the relation of heat production and heat dissipa- tion to this interesting phenomenon. His experiments were made on dogs, cats, and rabbits, both normal and with fever. He first established the fact that these ani- mals have practically the same daily fluctuations of tem- perature as man, the maximum temperature occurring from 7 to11A.M.,and the minimum from7tollp.m. As the result of his calorimetric observations, he found that * Reichert, Therap. Gaz., 1891, pp. 151, 242. + Mosso, Virch. Arch., vol. cvi., p. 80. + Reichert. Therap. Gaz., 1892, p. 386. : § Carter, Journ. of Nerv. and Ment. Dis., 1890, vol. xvii., p. 785. “the maximum and minimum of heat production and heat dissipation do not occur synchronously with the maximum and minimum of animal temperature. The two are entirely independent of each other”; also, “the heat production and temperature are entirely independ- ent of each other.” This was true in fevered animals as well asin healthy ones. There is no paradox in these results, for we must recall, as shown in § 3, that the tem- perature depends upon two factors, heat production and heat dissipation, and that either or both of these may vary, at the same time, in either direction. What Car- ter’s researches show is the interesting fact that there is something in the body of mammals which causes the balance between heat production and heat dissipation to be established on a different level at different times of the day, and that this something does not reside in the centres which control heat production, nor does it reside in those which control heat dissipation. Lichatschew * found a closer relation between heat pro- duction and diurnal variations of temperature than was found by Carter. Relation of the Size of an Animal to the Amount of Heat Produced.—As this is a subject of interest less from a medical than from a biological standpoint, and as its dis- cussion would require considerable space, it will not be entered into here. Most investigators give as a general law, that, ceteris paribus, the heat produced by an animal is directly pro- portional to the cube root of the square of the weight, while Reichert thinks that “if any distinct relation exists between body weight and the quantity of heat produced it is in direct proportion.” Those interested in studying this question more closely are referred to papers by Rosenthal,+ Reichert,t and Richet,§ the latter of whom takes up a discussion of the effect of artificial conditions of the skin, such as shaving an animal, coating it with oil, clothing, etc. § 6. CALORIMETRY IN PaTHoLoGy.—The chief use of calorimetry in pathology has been in connection with the study of fever. Some interesting results have also been obtained from investigating the effects on the sys- tem, of the products of the growth of specific micro- organisms; these latter will be taken up in § 7, on “ calo- rimetry in experimental pharmacology,” so that the present section will deal only with calorimetry in fever. Lavoisier’s theory, that animal heat resulted from combustions in the body, gained general acceptance about the beginning of the nineteenth century, and from that time until 1863 there was a strong feeling among pathol- ogists that pyrexia was the direct result of abnormally great oxidation in the body. The conflicting theory put forward in 1863 was that of Traube,| who attributed the pyrexia to retention of body heat, due to a constriction of blood-vessels in the skin, the result of which was to keep the heat of the blood from being lost by radiation at the surface. Traube’s chief opponent at this time was Liebermeister, who attributed the rise in tempera- ture to an increased heat production, denying that an increased heat retention ever took place. Numerous experiments have been made by indirect calorimetry, to determine whether there was an increased oxidation of food or of the tissues in fever, and the oxy- gen used, the CO, given off, and the nitrogenous waste excreted have all been taken into account. The results of these researches have not been in harmony, but from some of the most trustworthy we would gather that while the fever is on the rise, there is an increase in the oxygen used and the CO, given off, while the opposite is true for the decline of pyrexia. While the fever re- mains constant more oxygen is used and more CO, is given off than-in-health (nutritive conditions being the same), but there is not as high a percentage increase as when * See Richet’s ‘* Dictionnaire de Physiol.,”’ vol. iii., p. 135. + Rosenthal, Arch. f. Physiol., 1889, p. 31. + Reichert, Univ. Med. Mag., 1890, vol. ii., p. 225. : § Richet, article ‘‘ Chaleur,” in Richet’s “* Dictionnaire de Physiol.,” Paris, 1898, vol. iii., pp. 127-138. | Traube, Allgem. med. Centralzeitung, 1863-64. 569 Calorimetry. Camden, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. the temperature is rising. Most observers found that the respiratory quotient (vol. CO. + vol. O) is the same in fever as in health, but Regnard,* one of the most competent, says that it is diminished, which would mean that the character, as well as the amount, of metabolism was affected in fever. Such experiments as these give valuable information about the chemical processes in the body during fever, and show that in fever there is increased oxidation, and hence increased heat production, as a rule; but they do not settle the question at issue between Liebermeister and Traube, viz.: “Does heat dissipation enter as an es- sential factor?” This can be answered only by direct calorimetry, as pointed out by Senator + when he under- took the first thorough series of investigations on the subject. Leyden had already made this question the subject of calorimetric research, but his method was the unsatisfac- tory one of partial calorimetry by baths.{ His results, however, were in harmony with those of Senator and of Wood, in 1880, the latter’s experiments being the most complete we have in calorimetry on fever. These ob- servers all find that both heat production and heat dissi- pation play an important part in fever, thus showing that each of the older theories of Liebermeister and of Traube was partly right, but neither entirely so. This position has been substantiated by practically all later in- vestigations. Our present views concerning the general pathology of fever cannot be better given than by the following quotations from some of the numerous gener- alizations of Wood: § (a) “The rise of temperature in fever is not dependent altogether upon increased heat production, as in fever there certainly is sometimes less production of heat in the organism than there is at other times when the bodily temperature remains normal; also excessive heat produc- tion may occur even at the expense of the accumulated materials of the organism without elevation of the body temperature.” (8) “In fever a daily temperature variation occurs which is parallel to that seen in health, and differs from the normal variation only in having a higher mean.” (y) “In fever vaso-motor paralysis, when produced, is followed by an immediate fall of temperature similar to, but greater than, that which is produced by a like dis- turbance in health.” (0) “The decrease of heat production which follows section of the cord is much greater in the fevered than in the normal animal.” (e) “The so-called inhibitory heat nervous system is not paralyzed in fever, but is less capable than in health of answering promptly and powerfully to suitable stim- uli; in other words, it is in a condition of paresis or par- tial palsy.” (¢) “The clinical succession and phenomena of a febrile paroxysm, such as that of an intermittent, seem plainly to depend upon the nervous system for their arrangement and relation.” (7) “Irritative fever, if it exists, is produced by an action of the nervous system.” (¢) “Fever occurring in cases of blood poisoning is often, and probably always, the result of a direct or in- direct action of the poison upon the nervous system, and hence is a neurosis.” According to Mosso,| there are two kinds of fevers: one produced by the nervous system, and one independ- ent of the nervous system, which has its origin in the tissues themselves. He claims that cocaine produces fever through the nervous system; while cultures of staphylococcus pyogenes aureus, injected into the blood, * Regnard, ‘‘ Recherches expérimentales sur les variations patholo- giques des combustions respiratoires,’’ Paris, 1878. + Senator, ‘* Untersuchungen itiber den fleberhaften Process,” ete., Berlin, 18738, p. 2. +See § 4, ‘‘ Calorimetry by Baths.” § Wood, ‘Fever: A Study in Morbid and Normal Physiology,” Philadelphia, 1880; also ‘* Smithsonian Contributions to Knowledge,” No. 357, pp. 254 et seq. || Mosso, Arch. Ital. de Biol., 1890, vol. xiii., p. 483. 570 produce fever by direct action on the tissues. He has found that chloral will prevent the rise of cocaine fever, but is without effect on the fever produced by the staphy- lococcus. This question of the probable different origin of differ- ent fevers is an exceedingly interesting one, and would afford a fruitful field for further research. Certain drugs will influence one kind of fever but not another, anda careful study of this question would throw light not only on the action of drugs, but on the pathology of fever itself. Before leaving the subject of calorimetry in fever, two clinical papers should be mentioned, since each was written with direct reference to previous calorimetric work, and deal with the relation of the nervous system to fever. After reading them, one can scarcely doubt that “fever of purely nervous origin” exists. The papers are those of Drs. Hale White and Mary Putnam-Jacobi.* White,+ after a masterly review and synopsis of fourteen cases of lesions of the central nervous system, with clini- cal history and post-mortem findings, concludes that the results of Wood’s experiments on dogs are corroborated by clinical and pathological observations on man. § 7. CALORIMETRY IN EXPERIMENTAL PHARMACOL- ogy.—In this section it is not proposed to discuss the physiological action of the drugsand poisons considered, but simply to show which of these substances have been investigated by direct calorimetry, and what direct calo- rimetry has done for medicine along this line. Unfortu- nately, many of the findings which will be mentioned are based upon too few experiments, so that the value of this section will be to call attention to work thus far completed, and needing, for the most part, corroboration, rather than to show positively established facts in connec- tion with the drugs or poisons. Only researches employ- ing direct calorimetry are mentioned. DRuvGs. Antifebrin.—Hare ! finds that antifebrin reduces normal temperature, and in so doing affects both heat production and heat dissipation. In fever it reduces pyrexia chiefly by decreasing heat production. It seems to have little effect on pepsin fever (see Pepsin, this section). Antipyrin.—W ood, Reichert, and Hare? find that anti- pyrin lessens heat production independently of any action. on the circulation. They think it influences the chemi- cal changes in the body through the nervous system, especially the heat-inhibitory centre. Girard * found that a lesion (pzqire) on the median side. of one of the corpora striata produced less effect after giving antipyrin than before. Martin‘? destroyed Ott’s inhibitory heat centre, and found that antipyrin produced an increase of heat dissi- pation, the same dose not always giving the same quan- titative results. Heat production was reduced in four out of six cases. He compared hydroquinone, antipyrin, thallin, and kairin, and all gave the above result. “As. a rule, heat production followed heat dissipation, in its: ups and downs, although the drugs sometimes reversed. matters,” especially antipyrin. Gottlieb ® attributes the fall of body temperature, after antipyrin, exclusively to increased heat dissipation. He- says there is no concomitant diminution in heat produc- tion. Atropine.—According to Ott,* atropine causes increased: heat production and increased heat dissipation, the effect on heat production being the greater—consequently tem- perature rises. Lewis’ finds that small doses of atropine produced: increased heat production and diminished heat dissipa- tion, while with large doses the temperature fell with in- creased heat dissipation in spite of increased heat pro- duction. * Jacobi, Journ. of Nerv. and Ment. Dis., 1890, vol. xvii., p. 373. + White, Guy’s Hospital Reports, 1883-84, vol. xxvii., p. 48. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Calorimetry. Camden, Caffeine.—Reichert § finds that, under caffeine, heat pro- duction is always increased, while heat dissipation is not affected in any constant way. Curare modifies but does not check the action of caffeine. Carbolic Acid.—Hare! (p. 525) gives a summary of his work with carbolic acid as follows: ‘ Carbolic acid pos- sesses considerable power in lowering normal bodily tem- perature. It possesses more influence over pyretic tem- perature than does salicylic acid, generally preventing a rise or causing a fall of ternperature, but sometimes fail- ing todoso. Its mode of decreasing normal bodily tem- perature is as yet not fully understood, although it would seem probable that it acts on both heat functions. When reducing bodily temperature in fever, it acts chiefly by decreasing heat production, although it affects both functions.” Chloral.—Bevan Lewis’ says: “Hammarsten’s state- ment that the rapid fall of temperature is dependent upon diminished heat production . . . is, I consider, fal- lacious; in fact, all my observations tend to confirm the statement previously made, viz., that the heat production is greatly increased, and that the fall of temperature is really dependent upon the increased dispersion of heat from the body, ensuing from exposure during very gen- eral vascular dilatation.” i Cocaine.—As the result of a very complete research Reichert ® finds that cocaine increases both heat produc- tion and heat dissipation. Its action on heat production is much the greater, so that temperature rises. Curare seriously interferes with the action of cocaine. Curare.—See experiments of Kemp and of Reichert, § 5, Calorimetry in Physiology. Ergotine.—Ergotine, according to Bevan Lewis,’ pro- duces a fall in heat production, with fall in temperature, followed by a rise in both. Hydroquinone.—See Martin’s* “ Researches on Antipy- rin,” above. Hyoscyamine.—Bevan Lewis’ found that hyoscyamine always produced great commotion in heat production and heat dissipation, but no constant effect could be ascribed to it. Kairin.—See Martin’s “Researches on Antipyrin,” above. Neurin.—Ott}° found that neurin produced fever by action on the nervous system independently of the circu- lation. Pepsin.—Many forms of commercial pepsin, when rubbed up with water or salt solution, and injected into the blood, produce a decided fever apart from their action on the circulation. This fever is the result of an effect on both heat production and heat dissipation, the former being the more affected. The active substance in these cases is not pepsin, but proteoses and peptones, which are found along with the pepsin (see Ott,'° and Wood, Reichert, and Hare’). Peptone.—See Pepsin, above. Proteoses.—See Pepsin, above. Phenol.—See Carbolic Acid, above. Picrotoxin was found by Bevan Lewis’ to increase, enormously, heat production. The effect lasted longer than that of strychnine. Heat production then fell to a minimum just before convulsions set in. Quinine.—Wood, Reichert, and Hare? investigated the action of quinine with the calorimeter, and found both heat production and heat dissipation to be affected. We quote them as follows: “ We do not think that our results are sufficient to positively determine whether heat pro- duction or heat dissipation is the function which is pri- marily influenced.” They think that quinine’s chief value is due to its “stimulating or restoring the normal tone of the centres which are connected with thermogenesis, so as to enable them to resist the morbific fever-producing influences. Another author* finds that doses of 0.1 to 0.2 of qui- nine lower the heat production inrabbits. In normal ani- * These observations were found among the writer’s notes without a reference to the original paper. mals the diminution is from eight to eighteen per cent., in animals with fever from pigire the diminution may be as high as forty per cent. Salicylic Acid.—Hare! finds that salicylic acid can re- duce normal temperature slightly; it has little power over the temperature in fever. In reducing normal tem- perature it probably acts on both heat production and heat dissipation; its action on fever is uncertain and ir- regular. Solanine.—This alkaloid was studied by Bevan Lewis,? who found that its vaso-motor effect produced diminished heat, dissipation of heat, with consequent rise of temper- ature. Thisrise took place in the face of an enormously reduced heat production. Strychnine.—Bevan Lewis’ found that strychnine in- creased heat production—the best effects were from small doses. Chloral counteracts the effect of strychnine. Thallin.—Martin? found that thallin regularly in- creased heat dissipation, but had no constant effect on heat production (see also Antipyrin, above). BACTERIAL Porsons. Tuberculin.—D’Arsonval and Charrin* found that tuberculin raised the rectal temperature and at the same time diminished heat production. Pyocyaneus (bacillus).—Certain poisons produced by this bacillus had the same effect as tuberculin mentioned above.* Pyogenes aureus (staphylococcus). — See account of Mosso’s work in § 6, Calorimetry in Pathology. George I. Kemp. 1 Hare, Ther. Gaz., 1887, p. 389, 2 Wood, Reichert, and Hare, Ther. Gaz., 1886, p. 811. 3 Girard, Rev. méd. de la Suisse Romande, 1887. 4 Martin, Ther. Gaz., 1887, p. 289. 5 Gottlieb, Arch. f. exp. Path. u. Pharm., 1891, vol. xxviii., p. 184. § Ott, Ther. Gaz., 1887, p. 514. ane on Lewis, West Riding Asylum Reports, 1876, vol. vi., pp. 8 Reichert, Ther. Gaz., 1891, p. 249. ® Reichert, Univ. Med. Mag., 1889, vol. i., p. 448; and Ther. Gaz, 1891, p. 249. 10 Ott, Journ. of Nerv. and Ment. Dis., 1884. CALYCANTHUS.—(Properly Butneria.)—A genus of three species of shrubs in the family Calycanthacee, grow- ing in the United States. The bark and leaves of B. fertilis (Walt.) Kearney, commonly known as the sweet- scented shrub or strawberry shrub, are used in domestic practice as an antiperiodic. The plant is chiefly of inter- est because of the poisonous nature of the seeds, sheep being killed by eating the fruit. An alkaloid, calycan- thine, has been extracted by Dr. R. G. Eccles from these seeds. H, H. Rusby. CAMDEN, S. C.—Situated in the pinewood, sandhill region of the State, about 30 miles from Columbia and twenty hours from. New York. It is a town of 3,500 inhabitants, between 150 and 200 feet above sea level, and is a winter health resort particularly suitable for cases of pulmonary tuberculosis. The soil is very dry and porous, so that after a heavy shower the roads are not wet, the water quickly soaking into the sandy soil. The water supply and drainage are said to be good and the accommodations excellent, there being two hotels and a number of boarding-houses. The climatic data are as follows: Mean temperature (Fahrenheit): spring, 61.90°; sum- mer, 79.32°; autumn, 62.26°; winter, 45.16°. Average annual rainfall for twenty years, 42.22 inches. The cold- est noon temperature in February, 1890, was 50°; in March, 40°; in April, 50°. The warmest noon tempera- ture was: in February, 83°; in March, 81°; in April, 86° (Solly). The prevailing winds are south and southwest. In February and March there are some high winds, but generally the air is remarkably soft, dry, and balmy. *D’Arsonval, Arch. de Physiol., 1894, p. 362. 571 Camp Diseases. Camp Diseases. “Frosts occur at night only, and snow is exceptional.” The exaet number of sunny days is not known, but is said to be large. The relative humidity, though not known for this place, is probably not very different from that at Aiken, which is 59 per cent. for December, Janu- ary, and February. The oh ven advantages claimed for this region as a health resért are “its dry, balmy, bracing air, with con- ditions favorable for constant out-of-door life”; its dry, sandy soil; the pines, and its easy accessibility. Camden would appear to bea good resort for the open- air treatment of pulmonary tuberculosis, for cases not suitable for the colder regions or altitudes; also for con- valescents from influenza, pneumonia, or pleurisy, and . for those who merely desire to escape the dampness and cold of the Northern winter. Edward O. Otis. CAMP DISEASES.—There are no diseases peculiar to the soldier, but those by which he is chiefly affected are such as not infrequently occur among males of the mili- tary age in civil life. The conditions of military ser- vice, however, are often such that various factors predis- posing to deviation from the standards of health are greatly increased in potency; while the directly exciting causes often operate much more frequently, act over longer periods, and, in the case of infectious diseases, not rarely assume greater virulence. Since all these diseases have their counterparts in civil life, any extended dis- cussion of their etiology, pathology and symptomatol- ogy is unnecessary in this connection; and the treatment of such diseases also varies in no wise from that employed by the more advanced members of the medical profession throughout the civilized world. There remains, then, for discussion the relative importance of various diseases as affecting the health of troops; the predisposing causes, in so far as they are influenced by military service and conditions; the special methods of infection and the dis- semination of infectious material; and, finally, the means of preventing such diseases, as based chiefly upon the special military conditions by which the occurrence of the disease is favored or brought about. Excluding traumatism, the causes which chiefly im- pair the health and efficiency of troops, in garrison or during campaign, may be grouped according to their relative importance, as follows: 1. Diseases of an infectious character, the spread of which, in the military service, is favored by the aggre- gation of young and susceptible individuals, ignorant or careless in regard to matters of personal hygiene, living under conditions implying intimate personai relation- - ship, constant contact and, frequently, overcrowding. In many instances the necessities of military service re- quire an existence in unhealthful localities, favorable to the development of pathogenic micro-organisms and un- der circumstances in which their opportunities for dis- semination and entrance into the system are much greater than in civil life. In addition, the occurrence of these dis- eases is also often markedly favored by depression of the powers of vital resistance, depending upon great fatigue, exposure to inclemencies of weather, insufficient or im- proper food, impure water and vitiated air. These dis- eases assume far greater importance during active service in the field than in garrison, being the chief cause of in- efficiency among troops during campaign. 2. Diseases due to immoral or intemperate habits; as favored by an enforced celibacy, the absence of whole- some home restraint and the monotony often attaching to garrison life. These diseases are factors of the first importance in time of peace in raising the sick rates of an army, but during active warfare or field service they sink into comparative insignificance. 3. Diseases the causative agents in which are un- known, but which appear to be largely excited by expo- sure to cold, wet and dampness, whether they be found in camp or garrison. These affections have but little tendency toward a fatal result, and their importance from the military standpoint lies in the considerable pro- portion of temporary unfitness for service which they 572 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. produce. The number of soldiers who are temporarily in- capacitated for all or part of their duty, from these causes, is always large. 4, Affections due to extremes of temperature. Such are obviously related to climate and season, and are largely influenced by nature of service; being naturally much more frequent among troops on campaign than among those in garrison. 5. Disease due to an improper dietary; this being largely dependent upon facility of supply and transpor- tation, and hence being obviously more frequent among troops on active campaign or serving at remote, isolated, and newly established stations. 6. Disease directly induced by military service. This may be of a functional or organic nature, and is largely dependent upon the muscular labor involved in the exe- cution of military movements, the method of disposing the equipment upon the person, and the mental condition often resulting from field service and conflict. Patho- logical conditions of this character are rarely observed in garrison, but are by no means infrequent during cam- paign. In the detailed consideration of the diseases of the soldier, it is obvious that only such as exert a certain positive influence upon military efficiency require dis- cussion. To consider a number of rare affections, from the liability to which the soldier is no more free than the young man of the military class in civil life, and upon the oceurrence of which military service appears to exert neither positive nor negative influence, is clearly both unnecessary and undesirable. I. InFEcTIOUS DISEASES. AsIaTIc CHOLERA.—Occurrence.—The military history of cholera begins with the year 1757, when the British troops in India suffered greatly from its attacks. It is said that one division of 5,000 men had 500 deaths from cholera in a single day. In 1817, according to Rosse, in a force under Hastings the onset of a cholera epidemic was so sudden that sentries fell as if struck by lightning, and it required three or four men to stand a tour of guard duty of two hours. In five days there were 5,000 deaths, and the command wasalmost destroyed. In 1821, cholera made such ravages in the armies of Turkey and Persia that it forced military operations in Mesopotamia to be brought to an end. In the years 1830-1831 cholera ex- tended all over Europe and was shortly afterward brought to this country. Troops were attacked at a number of stations. At Fort Dearborn, on the present site of Chicago, it is stated by Rosse that 200 men out of a garrison of 1,000 were admitted to hospital with cholera in the course of seven days. During the Crimean War there were 7,375 cases of cholera in the British army, with 4,518 deaths. In the French army, at the same time, there were 12,258 cases with 6,018 deaths. Among the French troops composing the ill-fated Dobrutscha expedition, it is said that at one time no less than 10,000 men lay dead or struck down by cholera. Out of one battalion, besides those already dead, 500 sufferers were carried in the wagons. Coustan states that in one divi- sion of 10,590 men there were 2,036 deaths. In 1866, during the war between Austria and Prussia, more deaths occurred from cholera, in the armies of the latter country, than resulted from battle... At the close of the Civil War our troops suffered severely from cholera; there being, in 1866, 2,818 cases and 1,269 deaths. In 1867 there were 504 cases and 230 deaths, and in 1868 there were 7 cases and 38 deaths. Cholera almost destroyed a body of re- cruits marching from Leavenworth to Fort Hays, in Kan- sas, and wasalso epidemic at Fort Riley and other stations. It was carried by: recruits from New York to California, Louisiana, Texas and Georgia. In 1866 it also broke out in Brazil and the Argentine, and was carried by the armies into Paraguay. In the outbreak of 1878, in this country, our army was little affected, there occurring but 12 cases with 8 deaths; and since that year there have been no further deaths from this cause in our service. The ra Algeria. Rosse states that in Paris, for the period 1832- 49, and again in 1853, the mortality from this cause was 14.76 per thousand among the civil population, and 42.59 per thousand among the garrison troops. In many later instances, however, especially in the outbreaks of 1884 and 1893, the greater care as to sanitary conditions in the mili- tary service preserved the soldiers, while deaths occurred in the surrounding civil population. In the British army, during the decade 1888-97, cholera occurred among troops in India, Egypt, China, and Ceylon. In India, for this decade, the admission rate per thousand was 1.8; the death rate, 1.29. Cholera figures almost annu- ally in the returns for the Russian army, certain military garrisons of which are located in regions at which the disease endemically prevails. Recent figures for cholera in the Russian army are as follows: , Admissions per Deaths per | 1,000 strength. | 1,000 strength. 0.06 | 0.02 4.3 1.83 1.61 46 1.00 35 40 10 OL 002 Dissemination and Infection.—The specific. causative agency in cholera is given off chiefly by the bowels, and to a less degree in the vomitus. The length of time dur- ing which the stools of a cholera patient are infectious is unknown, but it probably is a considerable period. oie aiege sfoie.8. ravers (nie leis 60.91 Medical Department ........cccccscccccccccvssscveccoes 55.31 MTIEATIUC Viel os clelvie ris: alae nine wie erclesdloieio@ s\sluveislere eld nniole's « eivieies 46.28 Malarial fevers are much more common among soldiers than among officers. For the seven years 1890-96, the admissions in our army per thousand strength were 81.74 _ for enlisted men and 40.20 for officers. Common experience shows that a considerable number of individuals, exposed to the malarial poison, escape in- fection. While this may be due to a racial immunity, as already mentioned, the strongest predisposing element in the development of infectious disease, to which malaria is no exception, is a lowering of vital resistance through unsanitary surroundings, bad food, exhaustion, or expos- ure. Among these factors physical exhaustion is not of the least importance, and in this connection Coustan calls attention to the fact that in the late Madagascar ex pedi- tion the proportion of deaths among the French officers was 1:16.6, while among the soldiers, who were ex- hausted by the carrying of heavy burdens and long marching, the proportion was 3:5, Under-fed or fasting Fic. 1084.—Admissions for Malarial Fevers in the United States Army, Arranged According to Age, per Thousand of Each Class, During the Seven Years 1890-96, troops are very susceptible to malarial influences, and early morning drills before breakfast, or late guard duty, are especially favoring factors. Exposure to heat un- doubtedly exerts an influence favorable to malarial infec- tion, and the same is commonly believed to be the case with respect to alcoholic excesses. The acclimation of troops in a malarious country cannot be counted upon—military experience showing that the mortality increases with the length of the so- journ. Oneattack of malaria, unlike the eruptive fevers, predisposes to another; and it is an invariable rule in the French service to select for expeditions in the tropics only such as have not previously been affected with the dis- ease. After residence in a malarious country, with or with- out symptoms denoting malarial infection, the disease often appears in a persistent form after removal to a region in which there is no malaria, This has commonly been observed in recruits sent from malarious stations to healthful districts in the west, and was particularly evi- dent among our troops returned from Santiago. Prophylaxis.—This depends upon the application of both special and general measures of prevention, and of these the-former are probably of the most importance. Ya the avoidance of malarial infection by inoculation it is evident that troops should be shielded against the attacks of insects; further, that the insects should be destroyed. From the nature of military service it is ob- vious that soldiers cannot always avoid being bitten by mosquitoes, especially in the field. Much may, however, be accomplished to this end, and the less the number of bites the smaller are the chances of infection. In garri- son all doors and windows should be provided with screens, and mosquito bars should be attached to all beds. The nets should be square, should be hung inside a framework, tucked carefully under the mattress all around and stretched tightly better to allow the passage of air. The mesh may be fairly large, but should be free from rents. Care should be taken to destroy all mosqui- toes within the netting afterentering. Thisis best accom- plished by holding a light at one corner outside the net, toward which the insects fly and are readily despatched. In the field, in malarious districts, soldiers should be fur- nished with squares of mosquito net or head nets for use at night. The weight need not be more than a couple of ounces, and such a protection would conduce much to comfort and health and amply repay its carriage. In camps, smudges made of green boughs lighted to wind- ward, so that the smoke blows over the men, are often of great value. For this purpose the eucalyptus boughs, 585 Camp Diseases, Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. where they can be obtained, are said to be particularly val- uable, the mosquito having an especial antipathy to this tree. Oil of pennyroyal, or oil of cloves, smeared in small quantity over the exposed surface or dropped on the pillow, may keep off these insects, but being volatile, these substances require to be frequently renewed. In Italy, pieces of onion are often used for the same pur- pose. Mosquitoes which have gained access to barracks may be destroyed mechanically, or by the fumes from burning pyrethrum powder, tobacco, or even from green wood. The vapor of kerosene oil or turpentine also kills them. Leggings are an excellent protection for the ankles against these insects, but gloves or head nets can rarely be worn on the march, Still, except during night marches, malarial infections are probably rarely acquired: under such conditions. Since patients suffering from mal- aria are capable of directly infecting others through the agency of mosquitoes, they should always be treated un- der mosquito netting; and this precaution should be con- tinued for weeks after the actual fever has disappeared. When mosquitoes are present in barracks, suitable conditions for their development are usually found close by. In the case of the malaria-carrying variety, these are small stagnant pools. Where these cannot be filled up or drained, recourse should habitually be had to culicides for the destruction of the larve and pupex. For this purpose the substance most available for military use is kerosene or mineral oil. This should be sprinkled over the surface of the water, as with a broom, until a fine film is produced, which destroys the larve by cutting off the supply of air and choking their air tubes. The adult insects, which alight on the surface to deposit their eggs, are alsodestroyed. This film mustspread over the entire surface of the water, and should last at least two days, to kill the larvee as they are hatched from the eggs already laid. The quantity of oil required naturally varies with the conditions met with. For small, still pools probably one ounce of kerosene to each fifteen square feet of water surface is quite sufficient. Surface vegetation, sometimes very abundant, may often obstruct the mechanical action of the oil, and in waters even very slightly running the supply of the oil must be frequently or continuously renewed. Petroleum, also, has the dis- advantage of evaporating somewhat rapidly in warm weather. Potassium permanganate will destroy the larve, but only in solutions having a strength of five parts to the thousand. Strong infusions of tobacco are fatal to the larvee; and they are destroyed by powdered chrysanthemum flowers, as now found in commercial in- sect powders, in the proportion of three parts to the mil- lion. Recently, Celli and Casagrandi have shown that gallol, in the proportion of seven parts to the million, is the most certain and effective agent in destroying the larvee and possesses the advantage of great permanency. Whatever be the method employed, the life history of the mosquito shows that it should be repeated at inter- vals of from seven to ten days. The introduction of small fish or minnows into fishless breeding-places of the mos- quito is of great importance, as these feed greedily upon the larvee and soon exterminate them. General measures of prophylaxis have been shown by experience to be of much value in the prevention of mal- aria. It isnot advisable to take an army into a malarious country during the fever season, and in localities where fevers prevail to great extent it is well to retire to high ground during the malarial period, as is done by the Eng- lish in India and Jamaica and by the French in Guade- loupe. In locating a camp or post in a malarious district, special care should be taken in the selection of the site. In general, the appearance of the natives will give some knowledge as to the prevalence of this disease among them. The abandonment of a highly malarious post, in time of peace, is much to be desired and can usually be ac- complished. The retention of unhealthful posts is at the expense of unnecessary suffering, and in the past many thousands of lives have been uselessly sacrified to tenac- ity of position. With marching troops, zones of malari- ous country should be avoided or passed over as quickly 586 as possible. The abolition of marshes by flooding or drainage, and the removal of adjacent shrubbery and rank vegetation are great prophylactic measures in reducing the amount of malaria in a garrison. Plants of rapid growth should be cultivated for the assistance which they give in removing moisture from the soil. For this purpose the eucalyptus, castor-oil plant and sunflower appear to be most satisfactory, not only drying the ground but being shunned by mosquitoes. Subsoil drainage is often of great value, but this can rarely be thoroughly carried out in the military service. Barracks should be raised on piers, be cemented underneath and be of two stories in height. All water used for drinking purposes should be sterilized by heat. Foodshould be abundant and nutritious. Dis- tributions of hot coffee for those on guard at night, or engaged in arduous labor, are often of value. The use of quinine as a prophylactic, where troops are temporar- ily exposed to marked malarial influences, is of great im- portance, as has been repeatedly demonstrated. Not only are the cases of malarial infection greatly decreased in number by its use, but the character of the cases which occur is favorably modified. In general, a dose of gr. v. once daily will be sufficient, preferably taken shortly be- fore any unusual exposure isanticipated. Ina malarious country the general issue of a small dose of quinine, after anything lowering the resistive power, asa forced march, wetting, or lack of food, has much to commend it. In the Italian army, arsenious acid has been tried in the pre- vention of malaria, but with little satisfaction. Expos- ure, particularly to heat and night air, and over-exertion should be avoided. Thesoil should be disturbed as little as possible. If this should be necessary, as little as pos- sible should be disturbed at one time and the work should not be begun too early in the day. The minimum num- ber of men should be employed in the work, and only such as have not had a previous malarial infection. MEASLES.— Occurrence.—Among troops, this disease is of frequent occurrence. Under certain conditions, when developed under conditions of want, hardship, exposure, and bad sanitation—and especially when associated with a scorbutic taint—the disease may assume an extremely severe and fatal character. Formerly the occurrence of the hemorrhagic form of measles was not infrequent among troops, and was much dreaded. The exposure, often unavoidable, in the treatment of the sick in tent hospitals does much to develop secondary bronchitis and pneumonia; and to these latter causes are to be attributed also much of the gravity which the disease.has assumed when prevailing among troops during the existence of hostilities. In garrison, the mortality from this disease is small; for the period of peace, 1885-94, in our army, the death rate was but one one-hundred-and-tenth of the rate given by the Registrar-General for the total popula- tion of England and Wales during the same period. From 1832 to 1859, according to Rosse, measles was the cause of 2.7 per cent. of deaths from all causes occurring in the garrison of Paris. During the Civil War there were, in the Union forces, 75,177 cases with 5,174 deaths, the ad- missions per thousand strength during this period amounting to 31.72 and the deaths to 2.02. Among the Confederate troops, Eve states that measles prevailed to such an extent that whole companies, battalions and regiments, under organization, had to be disbanded and the men sent home. During the siege of Metz, measles was extremely prevalent and fatal in the garrison. In our army, for the period 1868-98, there occurred a total of 3,738 cases with 15 deaths, giving an admission rate per thousand strength of 4.50 and a death rate of .017. The disease appears to be more prevalent now than formerly among our troops, the rates being as follows: A Admissions Deaths Period per thousand. | per thousand. 1868-84 1.88 ~ 0,004 85-94 .. 4.85 004 13.72 090 , REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Camp Diseases, Camp Diseases, The expansion of our army with a large number of susceptible recruits at the outbreak of the war with Spain, and their aggregation in large camps where the dissemination of the disease was favored, did much to raise the rates for both admissions and mortality during the last period given above, the admissions for the year 1898 being 25.09 per thousand strength and the deaths from this cause amounting to 0.26 per thousand; while for the previous year of peace, 1897, the admission rate was only .82 per thousand, with no deaths. In the Ger- man army the rates of admission for measles, for varying periods, were uniformly low, as follows: Admissions Period. per 1,000 strength. Sse CETL OSS =I Searle orsis cas ciaeie,a(a'ciate.s's.0isss/ spect esagowiecie vases 1.4 rarer EM BOAT LB. aerate ctele alate, s eraieivie sie's:\psarere vig ah 'ein°s vislereiee 1.5 RENEE ROOM ODIO ioe oviciai dogs sve Sew See de vet ewe oe ceees eee 83 STIL ENS OS arcternic icy cielelr aeieis.civie'vis cee elec cialis sin vives celecle e's it For the French army the rates of admission per thousand strength, for the five years 1890-94, was 9.71. Coustan believes that the system prevailing in the French army, of turning intoa common magazine for storage certain articles worn by the men only during the period of the field manceuvres, greatly favors the dissemination of the infection of measles, and hence partially explains the high rates given by thatarmy. In the Austrian army, for the year 1897, the admission rate was only .8 per thou- sand, but the proportionate mortality was high, .02. Colored troops appear to be less susceptible to measles than are white, but certain mild cases are more liable to escape recognition in the former class; the rates of ad- mission in our army for measles, in 1898, were 25.91 per thousand whites and 14.42 for colored troops. During the Civil War the rates were 30.41 for white and 46.65 for colored troops, this excess as regards the negroes being apparently due to lessened efforts for the control of the disease among them. The disease occurs far more fre- quently among recruits than among old soldiers; in the Civil War the number of cases depending upon the pro- portion of susceptible individuals and occurring particu- larly among country-bred recruits. For the French army Coustan gives the following figures, as illustrating the effects of age and length of service on the occurrence of this disease : Less than one year|More than one year Year service, admissions| service, admissions per 1,000 strength.| per 1,000 strength. 23.63 12.69 99.62 4.04 11.98 6.08 14.80 7.91 In our own service, measles prevails to by far the greatest extent at the recruiting depots; in 1892, the re- cruits at Columbus Barracks furnishing more than half the cases occurring in the entire army. The disease or- dinarily occurs in time of peace most frequently during cold weather, when ventilation is comparatively re- stricted and the opportunity of infection is most favor- able. During the year of war 1898, when the number of recruits was great, the rate of admission was by far ~ the greatest during June and July, thus showing the greater importance of length of service as compared with season in influencing the occurrence of this dis- ease. During the same year the admission rate was 19.82 per thousand among soldiers stationed in the Unit- ed States, while there was a total rate of 48.25 for the troops serving in the West Indies and the islands of the Pacific. The case mortality of measles, as already noted, is capable of varying within very wide limits, ranging from as little as 1 or 2 per cent. in some out- breaks to 40 or 50 per cent. in others. “In Paris, during the siege (January, 1871), out of 215 of the Garde Mobile who took measles, 86, or 40 per cent., died; and the mor- tality reached very nearly the same figures among the French troops who returned to Paris after the Italian war, 40 out of 129 cases dying in one hospital whose sanitary condition was bad.” As in typhus fever, the concentration of a large number of measles cases, with deficient ventilation, appears unfavorably to affect the course of the disease through an intensification of the virulence of the infection. From analogy, it may be assumed that the cause of measles is a specific micro-organism, but as yet its special nature has not been determined. The infection is pre- sumably given off by the breath and mucus from the catarrhal surfaces, also by exfoliated epidermis. The poison undoubtedly is capable of being air-borne and tends to cling to fomites and remain in illy ventilated spaces. The materies morbi is very tenacious of life; and where it once fairly establishes itself, as has been appar- ently the case at Columbus Barracks, annual epidemics are the rule. There is no evidence that the disease is transmissible by water or food; infection probably al- ways occurs through inhalation. In a garrison, the dis- ease is not infrequently introduced by children. The incubation period varies from eight to twenty days, the usual limit being about eleven days. The infective period begins with the earliest symptoms; it is greatest while the catarrh and rash are present, and probably extends well into convalescence. As a general rule, in- fection is over by the end of the fourth week, provided that cough and desquamation have ceased. One at- tack of measles usually confers an immunity to future attacks. Prophylazis.—In civil life, vigorous efforts are rarely made to prevent the spread of measles. In the military service the opposite should be the case, bearing in mind that this disease is never devoid of danger, and, particu- larly in the field, may assume a grave character. Further, it causes the loss of a considerable amount of service by troops to which the state is entitled. In view of the fact that measles was mild under favorable conditions and was often extremely fatal when the patients were ex- posed to inclemencies, it was seriously urged, during the Civil War, to infect all susceptible recruits with this dis- ease, and only after recovery to send them to join their regiments. The prevention includes the isolation of the sick and the disinfection of all clothing, bedding, and surroundings. The discharges should be disinfected, particularly those from the mouth and eyes. For the latter purpose soft rags should be employed, and these burned after use. As far as the patient is concerned, Cameron concludes that “so far as figures are of value, ample air space, free draught, freedom from overcrowd- ing and from effluvium nuisances, conduce most to re- covery.” In the spring of 1898 the writer carried out some inves- tigations with regard to the production of an artificial immunity against measles. The experiments were abruptly interrupted by field service, but appeared to be distinctly favorable so far as carried out. The method employed consisted in the subcutaneous injection of blood serum obtained from convalescents from measles by means of cantharidal blisters. The’ injections were made in children living in an infected garrison, 5 to 10 c.c. being administered in three doses at intervals of about forty-eight hours. None of the cases so in- oculated contracted the disease, while a considerable proportion of the susceptible and uninoculated children became infected. Mumps.—Mumps occurs very frequently among troops, especially in young soldiers, but its mortality is prac- tically nil, and, like some other affections, it becomes of importance merely from the temporary disability for military service which it causes. In a total of 8,122 cases of mumps occurring in the United States army for the thirty-one years 1868-98 inclusive, there was not a single death which could be attributed to this affection. The admission rate for this disease for the period 1868- 84 was 2.99 per thousand; for 1885-94, it was 5.08, and for 1895-98, it was 4.05. The rate of admissions for the entire period, 1868-98 inclusive, was 3.76 per thou- sand. 587 Camp Diseases, Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. In the military service, mumps usually prevails in well- defined epidemics. Alarge proportion of the cases occur in recruits. The aggregation of such young men at cer- tain stations for purposes of instruction is very favorable to the occurrence of this disease; and in 1894, out of 337 cases of mumps occurring in the army, there were 119 cases at the two recruiting depots of Columbus Barracks and Jefferson Barracks. In the previous year, out of a total of 149 cases, 48 cases occurred at the first-named station. Orchitis and atrophy of the testicle are very common among soldiers affected with mumps, being pres- ent in about one-third of the cases. Coustan states that in an epidemic among French soldiers in 1891, every man attacked developed orchitis. Laveran found it 211 times in 699 cases. ; The infection is supposed to be given off by the breath and the secretions of the mouth, but as yet no specific organism has been isolated. It is not conspicuously dis- seminated by means of fomites; in garrison, it frequently appears to be introduced from outside by children. The period of incubation is reckoned as from fourteen to twenty-five days. The patient is regarded as infectious while there is any inflammation or tenderness of the sali- vary glands. Sanitary precautions consist in the isola- tion of the patient and the disinfection of his clothing and equipment. Beyond the cleansing and disinfection of the cuspidorsin the squad room, no further preventive measures, in view of the comparative triviality of the affection, will usually be necessary. Among soldiers mumps not infrequently occurs in close association with measles, but this apparent relationship is probably to be regarded as accidental. The disease is most common during the colder weather. AcuTE Croupous PNEUMONIA.— Occurrence.—Pneu- monia is a disease which, as might be expected, consid- ering the conditions of military life, though not one of the most common to which the soldier is exposed on ser- vice, is yet not of infrequent occurrence nor unproduc- tive of considerable mortality. Though ordinarily the disease occurs only sporadically, at times it appears to take on a distinctly contagious character; and well- defined epidemics of pneumonia among soldiers, either in garrison or in the field, are by no means infrequent. Under such conditions it is reasonable to assume the ex- istence of some common depressing influence, by which a number of individuals are predisposed to an infection, to which, under ordinary circumstances, they would be largely unsusceptible. In considering the prevalence of this disease in the military service, it should not be for- gotten that pneumonia may either occur primarily or be consequent to some other disease, particularly influenza and measles; and it is particularly during epidemics of the latter affections that the rates for pneumonia attain their maximum. While the disease occurs to some ex- tent among troops in garrison, it is considerably favored by the exposure incident to field service. : The rates in our army for pneumonia, since the Civil War, have steadily decreased as a result of the greater care given to the comfort and welfare of the soldier, as shown by the following figures: Dart Admissions per Deaths per Be ect 1,000 strength. | 1,000 strength. 1861-66 (Civil War). ccc srcis's «aie sieiste 32.45 es 868-84 te, ieee aoa Cecile eee eee 6.55 1.01 D8S5-O4. aire rcinticaya ata cleteenetoie' ots toebaterad 4.28 76 1895-08 ce... Sisrnushicanmeasaceme eae 3.66 1 Year 1898 (war with Spain)......... 4.84 83 Year [807 iiuvctee cue csatentos moeiacie oleree 2.96 al The case mortality of the disease has‘also greatly di- minished, but this is probably due to a more rational line of treatment than to any decrease in the virulence of the infection. As compared with the rates for foreign ser- vices, those for our army are extremely low. In the German army the admissions and deaths from pneumonia have been as follows: 588 ; Admissions per| Deaths per ee 1,000 strength. | 1,000 strength. 1881-82 to 1885-86 ......scceseccceces 11.0 0.19 1886-87 to 1890-OL 20.5. ictene eves vos 10.5 43 1891-92 to 1895-96 2... ecedevsscwees 9.3 .36 Voor 1896-07 <5 5 1898 and the decade 1888-97, the rates per thousand of English troops at different stations were as follows: YEAR 1898. DECADE 1888-97. nn = nN = Station. oa (are a Se foes Seu 84 | 32| 2 | gH 42/3 | 2a ||~2| 8 | Ba ALA |S FLAS United Kingdom . 1.9 | 0.22) 0.31 1.2 | 0.2 0.20 Gibraltar .... 4.2 | 1.82 74 5.4 .95 | 1.05 Malian css setae 21.2 | 6.88] 2.44 6.6 | 2.48 | 1.15 Egypt and Cyprus 81.0 | 23.40 | 11.12 || 21.3 | 4.87 | 3.90 @anadar cco. 2ees aes Nee te 1.3 21 25 Bermuda.... 15.0 |} 2.81 | 2.36 || 84.8 | 6.28 | 5.138 West Indies . abit DD 23 9.0 | 2.15 | 1.386 South Africa .. 82.9 | 55.77 | 4.88 |] 12.8 | 1.87 | 1.93 Mauritius'......... 14.6 | 4.86 | 2.87 || 15.0 | 5.84 | 2.15 GOVT ON. Gre ctersieretel asinlelelaie Seeernis 2.1 | 1.48 .09 6.9 | 2.138 84 CTIA irs aisiate wisieicaneiel occa eieio se 1.9 64 39 1.5 50 21 Straits Settlement ........... A a(iil Si ie 1.9 88 29 INGIRMG Ie co hence seca 36.3 | 10.04] 4.90 || 21.8 | 5.75 | ‘8.12 On averaging together the figures for the two cold stations, the United Kingdom and Canada, for the decade 1888-97, the admissions per thousand strength are seen to be 1.25, the deaths .22, and the constantly sick .22. For the same period the average rates for the remaining stations, located in hot climates or in the tropics, were: ad- missions, 12.4; deaths, 2.97; constantly sick, 1.92. From these figures it appears that British soldiers in hot cli- mates or in the tropics are almost exactly ten times as liable to contract the disease as those serving in cool cli- mates; while the liability to death from this disease is fourteen times greater. The apparently shorter course run by typhoid in the tropics, as expressed by the rates for constant sickness, is merely due to the higher rate of mortality, by which the elevation of the former figures, through tardy convalescence, is prevented. In our own service, for the year 1898, the admissions’ for this disease per thousand troops stationed in the tropical islands were 102.18 and the deaths 13.88; while of troops within the United States during the same period the admission rate was 85.46 and the death rate was 8.79. It should be remembered, however, that troops were exposed to tropical influ- . S S % 0 Mea peeks | real ra aes awa iam AES eee | ai pap iad soem =— SS SS Z. SS rnteric fever. WZ. Us the Decade 1875-84. sand strength, when the rate for the army as a whole was 88.56. This fact specifically demonstrates the im- mediately transmissible character of the affection. Causes Predisposing to Typhoid among Troops.—Typhoid fever occurs in all climates, outside the polar regions, but increases in prevalence as the equator is approached. In the British army, distributed asit is all over the world, the prevalence of typhoid varies greatly. For the year Typho-malarial fever, Fic. 1089.—Chart Showing the Distribution by Months, per Thousand Strength, of Cases Diagnosed as Enteric and Typho-Malarial Fever, Occurring in the United States Army During ences but a small part of that year, and that for full periods of ser- vice the difference in rates would undoubtedly have been much greater. Within the limits of the United States the influence of lo- cality is marked. The amount of typhoid fever in the Department of Texas is almost twice as high as in any other military depart- ment. In 1890 it was more than six times as high as in the depart- ments of the East, California, and Arizona. In 1897 it was fourteen times as high as in California, and much higher than in the other de- partments. Coustan states that typhoid fever is far more preva- lent in Algiers and Tunis than in France. As to season, the disease pre- vails especially in our army dur- ing the late summer and early autumn. For the decade 1875-84, as shown by the ac- companying diagram, the disease occurred least fre- quently during March and April and prevailed most ex- tensively in August and September. In the French and German armies it prevails to the greatest extent during and after the manwuvres in August and September; n the Austrian army its prevalence is greater during the July manceuvres. Certain notable outbreaks have oc- WN SESS 3S Se RO ew Roe eat SSS [| NSN aa 597 Camp Diseases, Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. curred in the spring, but these are invariably to be traced to a localized water-borne infection and are excep- tions to the general rule. Military experience shows that an infection of enteric fever often fixes persistently upon asingle barracks, post, or district. As a rule, in those localities in which the disease is endemic, it will be found that unsanitary con- ditions abound; notably impure water supply, defective methods and arrangements for the disposal of excreta, and want of care in respect to preventive measures. In India, typhoid fever has been found to be a more diffi- cult Biase to eradicate from military posts than cholera, persisting with great tenacity and recurring year after year in spite of all efforts—and it has even been found necessary to abandon stations for this reason. Within these endemically infected areas newcomers are especially liable to attack, those long resident in such a zone ap- pearing to acquire a relativ e immunity through repeated mild infections. Great importance was attached by Pet- tenkofer to the height of the ground water in endemi- cally infected regions; a low eround water, in his opinion, always coinciding with outbreaks of the disease. This relation between the disease and ground water appar- ently holds true for certain localities only and need re- ceive no serious consideration. Negroes and other colored races undoubtedly possess an immunity, in their native countries, to typhoid fever. By some this is regarded as a_racial ‘characteristic ; by others as an acquired immunity resulting from an at- es =n fe | 629 = aa eee fe] =i =a =a ee | a aa zal Q~ eet Vannes Fig. 1090.—Admissions for Typhoid Fever, per Thousand of Each Class, aie According to Age, in the United States Army During the Seven Years 1890- tack of the disease during childhood. In India the blood of the natives has been recently shown to give, in most instances, a positive reaction with Widal’s test. In our own service the disease is undeniably less frequent among the negro troops than among the whites. For the period 1867-83 the admissions per thousand white soldiers, for typhoid, not counting typho-malarial fevers as then recognized, amounted to 3.58, while the admis- sions for colored troops were 2.59 per thousand strength. For the year 1887 the admission rate for white soldiers amounted to 4.25, and for colored soldiers .93. During the decade 1887-96 the admission rate for white soldiers amounted to 4.74, and for negroes 2.43. It is interesting to note that for our few Indian soldiers, during this period, the admission rate for typhoid was only .47. During the year of war (1898) the relative insusceptibil- ity of negro troops as regards typhoid fever was espe- cially noticeable, the admission rate being 93.24 per thousand white and 27.64 per thousand colored troops— this, too, in spite of the fact that as a class the negro regiments saw harder service. On the other hand, when the disease has actually occurred the case mortality bas been much higher among the negroes than among the whites. Typhoid fever occurs only exceptionally among the native troops in India, and their immunity as com- pared with the immunity of white soldiers serving in that country has long been noted. As illustrating how great this difference in susceptibility really is, it may be stated that, in 1893, of the forces in India, typhoid fever 598 was responsible for 1.41 per cent. of the sickness and 42 per cent. of the mortality among the English soldiers, and for only .03 per cent. of the sickness and .4 per cent. of the mortality among the native forces. For the white race, nativity appears to bea factor of some slight importance. In the United States army, during the seven years 1890- 96, the admission rate for typhoid fever from the native- born Americans, per thousand strength, was 5.69, for the soldiers of German nativity, 5.41, and for the soldiers born in Ireland, 5.02. Typhoid fever is especially a disease of young soldiers. How much greater their susceptibility actually is can best be appreciated by reference to the accompanying diagram (Fig. 1090), in which the number of admissions are seen to decrease arithmetically by almost exactly one- half during each five-year period up to the age of thirty- five. Not only are young men more liable to contract this disease, but the mortality, also, among those affected is higher. "Thus for the period 1890-96, in our army, the deaths per thousand of each class were as follows: Age. Death rate. 19 Eabers ANA UNEP’. .isvs acls voc eve a 6 cceta oe Meant emer eae 3.32 BS Oe 69 BO £0 Bh 0's bcic ee ce dee o ase eeisldie ese seis ules ae Chmeleeettenaam 23 The case mortality for this period was 16.02 per cent. for soldiers nineteen years of age or under; 9.21 per cent. for those twenty to twenty-four years of age, and 8.89 for those thirty to thirty-four years of age. Length of service, in which fac- tor age must of course be considered to enter, also markedly influences the occurrence of typhoid. The re- port of the surgeon-general for 1885 shows the relative prevalence of this disease, excluding small frac- tions, among men of different peri- ods of service, to be as follows: Percentage Length of service. of cases. 6 months and under............ 48.0 Over 6 and under 12 months... 16 Over 1 and under 2 years ...... 14 Over 2 and under 3 years...... 5.5 Over 3 and under 4 years...... 4.5 All over 5 Years. wuciceclas seteentee Length of service not stated... 4.5 In respect to English soldiers in India, Eyre and Spot- tiswoode state: “The susceptibility of young soldiers to this fever is clearly shown in the length of residence in India; for while the death rate from typhoid was 4.98 per thousand in the first and second years’ service, among those in their third to sixth years and seventh to tenth years it was 1.55 and .55 respectively.” The report of the Sani- tary Commissioner of India for 1896 states that out of the total number of deaths at all ages from enteric fever, 78 per cent. were between twenty and twenty-four years of age and 86 per cent. were in the first year of resi- dence. In India, the prevalence of the disease appears to depend chiefly upon the amount of susceptible mate- rial presented. The influence of the branch of service upon the preva- lence of typhoid fever is by no means small. For the period 1867-83 inclusive, the admission rates per thou- sand strength were as follows: cavalry, 19; infantry, 4.6; artillery, 2.5. For this period the cavalry thus suf- fered more than seven times as much from typhoid as did the artillery, and nearly five times as much as the infantry, while its death rate was more than three times greater than either of the others. This great difference was largely due to the active field service against Indians required at that time of mounted troops. For the seven- year period 1890-96, the admission rates per thousand strength were 8.03 for the cavalry, 5.74 for the infantry, and 4.74 for the artillery. In time of peace the personnel drinking purposes. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. e Camp Diseases, Camp Diseases, of the medical department is affected less than any of the above arms of the service; but during the war with Spain it suffered more than twice as much as any of them. Overcrowding among troops certainly predisposes to epidemic typhoid fever; Marvaud gives figures to show that in the French army the mortality from this disease bears a well-defined relationship to the number of men aggregated at a post. In camp, the effects of over- crowding are particularly noticeable. This is perhaps due in part toa lowered vital resistance in the individual, but is probably chiefly dependent on the greater intensity of the infection resulting from the rapid propagation of the typhoid bacillus on a soil more highly contaminated with organic material, on which it possibly acquires more virulent qualities. Uncleanliness of person and surroundings is a power- ful factor in the development of the disease among troops. Particularly is this the case with regard to the care and disposition of the excreta, the most important and diffi- cult problem presented to the military sanitarian in the field. The common method of disposal of excreta and refuse in camp—by pits—offers many facilities for the development and spread of the specific micro-organisms. All collections of filth are liable to contamination and hence to become foci of infection. In garrison the accu- mulation of organic matter under floors, together with the seepage of moisture as a result of the use of exces- sive amounts of water in cleansing, affords an exceilent medium for the development of the microbe. The influence of great fatigue as a factor in the occur- rence of typhoid has been particularly noted by medical officers in foreignservices. The arduousand exhausting manceuvres which take place yearly in all the larger European armies are invariably followed by outbreaks of typhoid. It is well known that by over-exertion the bac- tericidal power of the blood is diminished and suscepti- bility to disease greatly increased. Coustan mentions, as applying in this connection, the experiments of Charrin and Roger, in which rats made to turn a wheel until ex- hausted succumbed readily to inoculation with an atten- uated culture of anthrax, while similar animals not so exhausted resisted the same inoculation. Insufficient or improper food, through the malnutrition or digestive disturbance which results from its use, may facilitate the invasion of the organism by the typhoid bacillus. Prophylazis.—In the prevention of an epidemic of en- teric fever among troops in garrison, a pure water supply is of the firstimportance. Ifthe water supply be regarded as liable to pollution it should, in garrison, be filtered through the Berkefeld apparatus before being used for In the field, and sometimes in garri- son, water is best sterilized by boiling—preferably by the Forbes apparatus. If the water is originally pure, as water in springs, deep or artesian wells, or unpolluted surface waters, it will only be necessary to insure against its contamination before use. With troops in camp, while the water should be good, an early and correct di- agnosis of the cases of this disease which first appeared is quite as essential. Since in camps enteric fever is more directly propagated from the sick, and the latter can through their discharges soon disseminate the dis- ease through large bodies of troops, the prompt recogni- tion and isolation of these cases, with the disinfection of their excreta, equipments, tentage, and surroundings, is of the greatest importance. As already intimated, the diagnosis of this disease is frequently a matter of much difficulty and may be impossible in all instances, but constant watchfulness on the part of medical officers will reduce this error to the minimum. The beard investi- gating the typhoid epidemics prevailing during the war with Spain concluded that less than half of the cases of this disease which occurred were correctly diagnosed ; but stated its opinion that, in recognizing this proportion, the army surgeon probably did better than the average physician throughout the country does in his private practice. Any such error of diagnosis, however, implies too great reliance upon the mere clinical symptoms of enteric fever—which, it has been stated, are frequently modified or largely lacking—and a too infrequent use of modern and more precise means of diagnosis, as found in the Widal test with blood serum and the diazo reaction in the urine. It is obvious that under many conditions of military service, particularly with marching troops, the former test can scarcely be applied, but in a fixed camp or garrison it can always be carried out—and the tech- nique of the diazo reaction is possible under any circum- stances. These tests should be habitually applied to every case presenting fever the nature of which is not promptly and definitely recognized as being other than typhoid. Since the Widal and diazo reactions may not be given at certain stages of enteric fever, they should be repeated one or more times in possibly suspicious cases. When typhoid fever is recognized as existing, the af- fected individual should promptly be isolated. If in gar- rison, the clothing and bedding of the patient, together with the water-closet or latrine used by him, should be disinfected. If the case occurs under canvas these pre- cautions are required, and in addition the disinfection of the clothing and bedding of those sheltered with him should be sterilized. The tent itself should be disin- fected. If possible the camp, or at least that of the com- pany organization in which the case occurred, should be moved. If this be not possible, the site occupied by the infected tent should be vacated, policed and exposed to the sun. It should not again be occupied. In many in- stances it would, in addition, be desirable to freely scat- ter fresh lime over the former tent area. Since many cases of enteric fever in camp will not be recognized, it should be the rule to regard all human ex- creta as infected, and, where a camp has a permanency of more than three or four days, systematically to carry out measures for the destruction of its presumably nox- ious qualities. The cost of an epidemic of typhoid will be many times the additional expense of these justifiable precautions. In all camps of any permanency the use of excavated latrines should be prohibited, and either the trough system or crematories, as now used in our army, provided. Under the same conditions, urine tubs should be provided for night use and their utilization enforced. Careful police of the camp, with cremation of refuse, should be carried out, to limit soil contamination and prevent the development of the fly plague. A careful sanitary police is very effective in preventing the devel- opment of these insects in very great numbers; but where the plague actually exists the only recourse is toabandon the infected area for a new site, preferably to be located to the windward and at a distance of at least two miles. Other general methods of prophylaxis consist in the allotment of abundant space in the arrangement of the ‘camp; the free exposure of the interior of tents—and of their contents—to sunlight and fresh air; cleanliness of person on the part of the troops; an abundance of good food and, in time of epidemic, the avoidance of exhaust- ing drills and exercises. It is important that a presum- ably infected camp site should promptly be abandoned; though if troops be allowed first to become generally in- fected the procedure is not as efficacious in controlling typhoid fever as in some other diseases, With respect to the measures to be applied to prevent further spread of the infection from the sick, the proper disinfection of the excreta is of the firstimportance. All discharges should be received in a solution of milk of lime. The nates of the patient should be cleaned with paper and afterward with a bit of compress cloth wet with a dilute disinfectant solution. The bed pan should be covered with rubber sheeting and removed at once. In garrison, the contents of the bed pan should be thor- oughly mixed and allowed to stand for half an hour before pouring into the slop hopper; in the field it should be burned at once. The practice of burying typhoid discharges, after measures of disinfection by chemical means, is strongly to be deprecated. In certain instances all the bacilli undoubtedly will not be destroyed, and it 599 Camp Diseases, Camp Diseases. has been shown that they not only develop in organically polluted ground but may grow upward through a con- siderable depth of earth. Even if buried deeply there is alwaysa possibility of their future disturbance. Whether in camp or garrison, the cloth compresses used to cleanse the patient should be destroyed by fire. The bed pan, rubber cover, and slop hopper should be cleansed with disinfectant solution, and the two former wiped dry. Both should be placed in a closed receptable to prevent access by flies. All sputum should be received in spit cups containing a disinfectant solution. Feeding uten- sils should be cleansed in boiling water immediately after use, and any uneaten remnants of food at once dis- infected by burning or scalding. All bed linen, body clothes, and towels soiled by discharges should be im- mediately rolled in a clean sheet wet in bichloride solu-. tion, and removed for appropriate disinfection. Bed spreads and blankets should be sunned and aired as often as possible. They should not be shaken any more than is absolutely necessary. Bed and body linen should be changed daily; rubber sheets should be used over the mattresses. Flies should be kept away from the patient, not only for his comfort, but to prevent the transmission of the disease to others by their agency. After attending to the wants of a typhoid patient, the hands of the attendant in each instance should be rinsed in a disinfectant solution and then washed in warm water, using soap and a nail brush. The urine of patients convalescent from this disease should be examined at frequent intervals for the typhoid bacillus. Return of convalescents to duty or quarters before this bacillus has been absent from the urine for at least one week should not be permitted. To effect the sterilization of the urine, where this bacillus is present, Richardson and others recommend the use of urotropin, in doses of gr. x. three times a day. Saloland other sub- stances appear to have little value for this purpose. Preventive Inoculation.—The problem of preventive in- oculation against typhoid fever, now receiving much at- tention, has a special importance for the military sani- tarian. Bokenham endeavored to producea prophylactic and curative serum by the immunization of horses through the repeated injection of living and dead cultures of the bacillus; but the serum thus obtained was not of sufficiently great potency to give it a practical value, and no means could .be found of precipitating or con- centrating what strength the serum contained. Pfeiffer, Wright and Semple, and others, then endeavored directly to produce in man the immunity which it was shown could be created in animals. At first these investigators cultivated virulent cultures onagar, making up an emul- sion of these cultures with bouillon so that each cubic centimetre contained about 2mgm. of fresh agar growth. The microbes were then killed by exposure to a temper- ature of 56° C. for several hours. was used as a dose, the liquid being well shaken. Re- cently Wright has attained more satisfactory results by cultivating the bacilli directly in bouillon. After incuba- tion at 37° C. for a period of from fourteen to twenty-one days, the culture is sterilized by exposure to a tempera- ture of 60° C. for five minutes. Thisis done by drawing the emulsion into small sterile tubes, which are sealed and placed in a beaker of cold water which is gradually raised to the desired temperature, and this is maintained for the period above noted. Agar tubes are then inocu- lated with the material to make sure of its sterility. Before injection, .5 per cent. of lysol is sometimes added to neutralize any accidental contamination. The amount used for human inoculation is two-fifths of the minimum amount which would be fatal to a guinea-pig weighing 250 gm. The immunizing material appears to be valu- able rather on account of its antimicrobic than its anti- toxic properties. While the reaction following the inoculation is usually slight, it is at times somewhat severe. Rigors, nausea, and a tendency to syncope sometimes occur. There is a well-marked local reaction, which, however, never ad- vances tosuppuration. Where the inoculation is success- 600 Of this emulsion 1 c.c.° REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ful, the blood serum acquires the specific agglutinative property to a marked degree. Cameron found in his own case that at the end of twenty days the agglutinat- ing power of his blood serum was increased forty times; and an increase to this extent. has been shown by other observers to bea common result. In general, the aggluti- nating property is equal to that conferred by an attack of the disease itself. It is not known how long the in- fluence of the inoculation persists; and whena protection lasting more than two years is desired, it is recommended to insure a good reaction by repeating the inoculation after an interval of one week. At present, experience with these inoculations has not been sufficiently comprehensive to warrant the drawing of exact conclusions. The inoculations have been car- ried out on a considerable scale, however, with the sanc- tion of the British military authorities, on soldiers volun- tarily submitting to the operation before leaving for the recent scene of hostilities in South Africa. Foulerton states that reports so far received from South Africa show that typhoid fever has occurred at the rate of six to the thousand among the inoculated and nine to the thousand among the uninoculated. Figures given by Wright based upon 11,295 British soldiers in India show that .95 per cent. of the inoculated contracted the disease where 2.5 per cent. of the uninoculated were attacked. These re- sults, while not brilliant, are certainly encouraging, and render the method well worthy of general use among young soldiers; particularly since the inoculation, when properly performed, is quite free from danger. Typuus FrEver.—Occeurrence.—A chapter might be de- voted to the historical pathology alone of typhus or spotted fever. The disease is as old as the disputes of nations, and has prevailed in formidable epidemics among troops in the field from 400 B.c. down nearly to the pres- ent time. During peace it has always been of compara- tively subordinate importance, although its occurrence in armies has given rise, from time to time, to disastrous outbreaks among the civil population. It is known to have prevailed during the Peloponnesian war; and in 1489 it destroyed 17,000 of the troops of Ferdinand at the siege of Grenada. In 1528, at the siege of Naples, over 5,000 of the French nobility lost their lives from typhus in a period of about three weeks, and the French army of 30,000 men was almost destroyed. In 1542, in the German army at Ofen, according to Hauser, typhus claimed 380,000 victims. Before Metz, in 1552, the be- sieging Spanish army lost 30,000 men in less than two months, compelling the abandonment of the siege. The roads taken by the retreating army were said to have been lined with the dead and dying. In 1556, it deci- mated thearmy of Maximilian II. In 1620, the Bavarian troops serving in Bohemia lost over 20,000 men from spotted fever. In 1628 and 1632 the disease ravaged the Swedish army. Both the Royal and Parliamentary ar- mies in England, in 16438, suffered severely ; in the wars of Louis XIV. it caused enormous losses in the French army. At the siege of Torgati in 1760, it is said that over 80,000 men, out of a total of 85,000, died of this disease in a few months. Typhus is reported as having been one of the great factors in the mortality of our troops during the Revolution; and in 1790 the losses among the Russians. from this disease were so great that operations against. the Turks had to be suspended. In 1799 typhus deci- mated Genoa and the French force besieging it. The greatest recorded ravages of this disease, however, oe- curred during the wars of the first Napoleon. At Sara- gossa, out of 100,000 people, 54,000 died, chiefly from epidemic typhus. At Dantzic and Wilna, in 1803, and during the retreat from Moscow, vast numbers of French troops are recorded as having perished fromtyphus. In May, 1812, the Bavarian allies of the French mustered 28,000 men; in February, 18138, it is said that this disease: had left but 2,500 to bear arms. In August, 1813, the first Prussian army of 60,000 men had lost one-sixth of its strength from an epidemic of typhus. Murchison . states that in Mayence alone, of the 60,000 French troops composing the garrison in 1813-14, no less than 25,000 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ¢ died of typhus in six months. According to Rawlinson, of the French armies around Paris, after the retreat from Russia, 40,000 men are recorded as having died of typhus in six weeks, one-fifth of the remaining force being sick. This disease raged in all the contending armies during the Crimean War, particularly among the French troops. Aitken says: “In the spring of 1856 it was computed that more than 17,000 men of the French force perished in less than three months, chiefly from typhus.” Bau- dens declared that of the typhus cases in hospital in Feb- ruary, 1856, two-thirds were devoted to certain death. The deaths during this outbreak among the French medi- cal officers amounted to 48, and there was scarcely one «that escaped attack. Typhus undoubtedly did not occur during the Civil War, although there were a small number of cases diag- nosed as this affection. These were undoubtedly ful- minant typhoid. It prevailed among the French troops in Mexico, especially on board the ships which conveyed the colored contingent from North Africa. Coustan says that the French troopsin Mexico “suffered a cruel loss.” In 1862-63, and again in 1867, typhus attacked the French garrisons, in Algeria; Marvaud stating that of one body of 3,500 troops, 1,200 died. Its existence dur- ing the Franco-German War in 1870-71 is disputed. During the Russo-Turkish War in 1878 it was said that at one time the cases of typhus were so numerous in the Turkish army as to threaten its disorganization, and the conditions in the Russian army were not much better. After the capture of Plevna, according to Coustan, 50,000 men out of a total of 120,000 died during the period of inactivity, and in May and June of 1879 it is stated that half the Russian forces near Constantinople were pros- trated with this disease. Typhus, in the military service, is essentially a disease of campsand sieges. Of late years typhus has lost much of its dangerouscharacter. Its geographical distribution is not great, and at present, in time of peace, it occurs only among troops stationed in Southeastern Europe, where the disease is endemic. In the Russian army for the period 1890-97, the rates per thousand were as fol- lows: Year Admissions. Deaths. RUUD WEN ors otal ad alele sitive a vis-s.o%s we'd ve's 0.6 0.04 AS) 07 1.8 14 yor "05 3 03 3 02 Be .02 In the Austrian army there were 9 cases in 1897, 4 in 1896, and 8 in 1894. There has been no well-authenti- cated outbreak of this disease in our army within the past half-century. A number of epidemics of typhus have, however, occurred in the civil population of the country—the infective agent being in every case im- ported from abroad. Direct and Predisposing Causes.—The specific exciting cause of typhus fever has not as yet been isolated, though undoubtedly such a factor exists. Recently, in Russia, it is said that the disease has been experimentally pro- duced by inoculation with the blood of typhus patients. It is universally admitted that the most important influ- ences predisposing to its epidemic occurrence are want, misery, and hardship. Typhus appears to be largely favored by overcrowding and lack of proper ventilation. Cold weather, as shown in the Crimean War, indirectly promotes its occurrence among troops for these reasons. Viry notes that typhus was prevalent in public institu- tions in the city of Metz, in 1870, when it did not appear among the French troops living in shelter tents just out- side the walls. Poor food, dampness, fatigue, and other conditions lowering the resistive powers—together with psychical depression—have much to do with epidemics of this disease. Camp Diseases, Camp Diseases, Typhus fever is highly contagious, in the strict sense of the word: and there is probably no disease which has been proportionately more frequently contracted from the sick by their attendants. At Plevna, nearly all the medical officers were attacked: during the Crimean War 12.8 per cent. of medical officers and only .4 per cent. of line of- ficers, among the French troops, died from typhus. The specific virus appears to be distinctly transmissible from the sick to the well through the surrounding atmosphere. While nothing is known of the causative agent, infection appears to occur by way of the air passages. The poison may be harbored by and carried from place to place in fomites. Jacquot, in speaking of typhus in the Crimea, says that “wherever troops affected with typhus have camped, the dejections and excretions which have satu- rated the ground are fatal to troops which follow them.” The morbific agent appears to exist long in infected clothing and dwellings. The activity of the specific virus is favored by unsanitary conditions, and where the disease is introduced among troops which are poorly nourished and clothed and living under conditions im- plying overcrowding, there is every likelihood of an epi- demic cutbreak of the fever. The incubation period is variously stated at from six to fourteen days, though there appear to be some well-authenticated cases in which it was not more than from two to five days. The disease is most. common during the period of youth and early maturity, as found in young soldiers; but the mortality is lower than among those of greater age. Prevention.—It is manifest that: the prophylactic meas- ures against the disease are those that aim to prevent its introduction from without, and those that are designed to eliminate all local conditions favorable to its develop- ment. Quarantine against infected points should be rig- orously maintained. When the disease occurs among troops in garrison, the sick and well should promptly be placed under canvas; for the influence of fresh air upon the virulence and vitality of this disease is undoubtedly of the highest importance. The command, if large, should be broken up into smaller bodies. Especial at- tention should be given to the prevention of overcrowd- ing, to insuring the abundance and proper preparation of food, to the avoidance of fatiguing exercise, and to the maintenance of strict sanitary police. Careful watch should be kept for suspicious cases, and these should be at once isolated. It should not be forgotten that the ag- gregation of large numbers of the sick increases greatly their mortality, as well as the danger to the attendants. Tent hospitals should preferably be used, the supply of fresh air being unlimited and the floor space allowed to each patient being about two hundred square feet. As the contagion is especially virulent near and about a patient, attendants should avoid inhaling the emana- tions or exposing themselves unnecessarily to such in- halation, unless protected by a previous attack. They should not stay in the immediate vicinity of typhus patients longer than necessary and should never sleep in a ward. They should take plenty of sleep and good food, and should frequently employ disinfectant solu- tions on the face and hands. The attendants, like the sick, should of course be quarantined. Careful disin- fection of bed and body clothing and excreta is always called for. The barracks or wards, as well as all articles of furniture, clothing, or equipment contained in it, should be disinfected and thoroughly aired after removal of the patient. YELLOW FEVER.—Occurrence.—Yellow fever is essen- tially a disease of tropical and sub-tropical countries, and is ordinarily restricted to well-defined geographical limits. Bodies of troops serving within these limits for any length of time have uniformly been more or less affected by it. In 1648, “there occurred in Havana, and in the fleet of Don Juan Pujados, a great pest of putrid fevers which remained in the port almost all summer. A third part of the garrison and a larger part of the crews and passengers of the vessels died.” The disease was ex- tremely fatal among the British troops which subse- quently captured Havana; and it is interesting to note 601 Camp Diseases, Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. that the regiment of loyal Americans recruited for this expedition, largely from the south, was least affected. In 1740, in the expedition against Carthagena, its effects were most disastrous. In 1780 a force of 8,000 Spanish soldiers was landed at Havana, and in two months it lost 2,000 men from this disease. In Hayti, during the rebellion of the blacks, the French army of veterans was practically annihilated by yellow fever. Of this epidemic Lemure wrote: “In 1802 an army under the orders of General Leclerc embarked for San Domingo. The effective strength, on leaving Brest, was 58,545 men. In four months 50,270 men were dead; chiefly of yellow fever, which gave 82.5 per cent. of the mortality. Of JANUARY FEBRUARY AUGUST SEPTEMBER OCTOBER NOVEMBER OECEMBER SNS EHERE SERA REaeAe ASSESS cal S SSSSSNSSSASE EEE EE EEE ze DISS SIS ime +4 NISISISISISIISS 1876-77 1396 - LLL Fig. 1091.—Distribution by Months of Deaths from Yellow Fever in the Spanish Army in Cuba, per Thousand Strength, During the Epidemics of 1876 and 1896. the 8,275 men remaining, 3,000 were sick or wounded. In 1809, seven years later, this army was reduced to 300 men, who returned to France.” The French also suffered severely during their occupation of Mexico. According to Coustan, there were 1,705 cases; the fever breaking out six days after the troops landed at Vera Cruz. Dur- ing the Civil War there were, in the Union forces, 1,371 cases and 486 deaths; and in 1867 the disease attacked a number of Southern posts and caused 1,520 cases with 453 deaths. For the period 1868-84 the disease recurred almost annually among such troops as were stationed in the South, the average for the whole army for this period, per thousand strength, giving a rate of .78 for admis- sions and .33 for deaths. For the period 1885-96 inclu- sive, there were no cases of yellow fever in our service. 602 In 1897 there were 7 cases with 3 deaths; and in 1898, at Santiago, there were 604 cases with 70 deaths. For the period 1868-98 the rate for admissions was 1.17, and for deaths .26 per thousand strength. The Spanish army in Cuba has always suffered severely from this disease, es- pecially during the epidemics of 1876, 1877, and 1896. The British and French troops stationed in the West Indies, have been repeatedly attacked. Vature and Mode of Dissemination.—With regard to the nature of the materies morbi of yellow fever nothing is as yet known, though investigations by many army medical officers have been, and are now being, vigor- ously prosecuted; hence it is impossible to say definitely whether it is disseminated by water, air, or insects. It is safe to regard the excreta of a yellow-fever patient as especially infectious. There is an abundance of evidence to show that yellow fever may be transmitted in clothing, merchandise, or similar articles. Such fomites as have been in the immediate vicinity of yellow-fever patients are to be regarded as especially dangerous. Infected habi- tations in the yellow-fever belt are probably the chief points from which the disease is spread. Apparently, the yellow-fever patient, removed to good surroundings, is not so greatly to be feared as is the place in which the sufferer contracted his infection. Experience has shown that, with proper precautions, those in attendance on the sick are not especially liable to contract the disease; and yellow-fever patients have often been treated in the same wards as susceptible patients without the disease having been disseminated. Such practice, however, is of course highly undesirable. While the patient, therefore, does not ordinarily affect others directly, he undoubtedly gives off, presumably in his discharges, the virus of the dis- ease, and this is capable of infecting a particular locality and thus of giving rise to the disease in others. Outside the body the micro-organism probably undergoes devel- opment in the soil. The incubation period of the disease is short, varying from one to five days. Predisposing Causes.—Absolute immunity to yellow fever is not possessed by any race as a peculiar charac- teristic; though relatively speaking, those individuals who are permanent residents in the endemic zones ex- hibit less liability to contract it than do strangers newly arrived from colder latitudes. In general terms it may be considered that the susceptibility to, and mortality from, yellow fever vary directly with the distance from the equator of the place of nativity and residence of the individual. According to Barton, of each 1,000 deaths from yellow fever which occurred in New Orleans in the epidemic of 18538, the distribution of mortality was as follows: Native Creoles.oescsjc:s9 09.0 dis ci as ale.c:e'ele eia'ets leans lela lslereietaneea 3.58 Strangers from West Indies, Mexico, andSouth America 6.14 Strangers from Southern United States.............06+ 138.22 Strangers from Spain and Italy. .........eces «cesses 22.06 Strangers from Middle United States ................0. 30.69 Strangers from New York and New England;.......... 32.83 Strangers from Western United States ............20e0. 44.23 Strangers from Brante: = baci eis ere eis riers els alee eae 48.13 Strangers from British AMEYIC@...........cececoesceses 50. Strangers from ‘Great Britaim 2. s/c sc cies siciemleteeieee 52.19 Strangers from Germany: 2.2. ccc pes ce se cele eeteenirenel 182.01 Strangers-from’ Scandinavia... <.0s6s. sce cesaeneenne 163.26 Strangers from Austria and Switzerland ............... 220.08 Strangers from: the; Netherlands’ <5 -.%. <1.0)2« 1 cemtatiomnna 328.94 Long ago Blair wrote that among the West India island- ers in the Seamen’s Hospital at Demerara, Guiana, the percentage of deaths from yellow fever was 6.9; among French and Italians it was 17.1; among English, Ivish, and Scotch, it was 19.3; among Germans and Dutch it was 20; among Swedes, Norwegians, and Russians it was 27.7. It has been thought that the Creole and the African, irre- spective of place of birth or of residence, possess a racial immunity to yellow fever. This, however, does not ap- pear to be the case. Such a relative immunity is prob- ably only the result of an attack of the disease itself, which in early life may be so mild as scarcely to be rec- ognized; or, to a much less degree, it may be due to the transmission of a relative unsusceptibility from ancestors immunized for generations through attacks of the disease. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Camp Diseases, Camp Diseases, It should be noted that the immunity to this disease un- doubtedly possessed by many natives in the yellow-fever belt is more or less completely lost after they remove to cooler latitudes, and that such individuals on their return to the zone of endemic yellow fever often exhibit a suscep- tibility equal to-that of total strangers to the district. There is, therefore, no reason to believe that the negro pri- marily possesses any greater powers of resistance than does the white man under the same conditions, or that the negro born and resident in cold climates is as unsuscepti- ble as the negro from the yellow-fever belt. Anacquired oran inherited immunity is the essential factor. It should be noted that yellow fever prevailed among the negro troops at New Orleans during the Civil War and caused considerable mortality. Thus also for the year 1898, the rates in our army for this affection, per thousand strength, were as follows: Admissions. Deaths. We TEEPOUDS Mata tains cals neiaeiecieis ceisie tbe o.cie« 9.40 1.04 IONE CULOODS's ovis sccjetlsie. 60's sels. cies ei oven a's 59.19 7.51 The negroes recruited for our service are rarely drawn from districts in which the disease has prevailed. The great difference above noted in favor of white troops, however, is largely to be explained by the fact that the colored troops of our army were nearly all present at Santiago, while a much less proportion of the total white troops were so exposed. Further, one colored regiment, on account of its supposed relative unsusceptibility to this disease, was selected to do guard and police work at the yellow-fever hospital, thus largely increasing its oppor- tunities for infection. A fair comparison of the suscepti- bility of the unacclimated white with that of the negro native to the yellow-fever zone may, however, be drawn from the British troops in the West Indies. For the dec- ade 1888-97 the rates for yellow fever, per thousand strength of these troops, were as follows: Ad- Constant missions. Deaths. sickness. SHEE CI DEATIS calelcierstviete'c e's.s, s10.4:5.0 sve! 0.6 e's, ¥-* 3.0 1.66 0.16 PROUSDUTOPCEDS stacic ces ccs cecscciscsss A 15 02 Prophylazis.—As a preventive of the occurrence of yel- low fever among troops, expeditions into an endemically infected district should not be carried out during the rainy season. Troopsintended permanently to garrison infected points will be with advantage recruited from the native andimmune population. Whether in camp or in garrison, general prophylactic measures of great importance have reference to careful sanitary policing, free ventilation, an avoidance of overcrowding, and a pure water supply, with proper means of maintaining personal cleanliness. During the Civil War the comparative freedom from yel- low fever of Union troops garrisoning New Orleans was regarded aschiefly due to the vigorous sanitary measures introduced by General Butler. Recently, in the occupation of Cuba, the value of proper sanitation in controlling the disease has been strongly demonstrated. Troops should be prohibited from entering infected towns, and particu- larly from entering houses and shops. When an epi- demic occurs among the surrounding population, a care- ful quarantine should be maintained. With the outbreak _ of the disease among the troops all cases should be promptly isolated, preferably in tents. from the sick, especially the vomit and excreta, should be disinfected; if possible, by fire. The clothing and equipments of the soldier, and those with which he may have come in contact, should be disinfected; as should the tent or barrack in which the case occurred. If pos- sible, the troops should be moved to a locality in which the fever has not been known to occur. In this country troops have habitually been transferred from southern stations to Atlanta, when an outbreak of the disease was apprehended. If such a locality is not available, the troops should be moved to high ground—preferably to All discharges ~ an elevation of at least fifteen hundred feet. Moving camp even a mile or so may avert an epidemic, and this procedure should be repeated upon the appearance of every new case. Depopulation of an infected area is es- sential, a fact repeatedly demonstrated in our own ser- vice; as at Fort Brown in 1882 and at Santiago in 1899. If the disease appear on board a transport, the sick should be treated on deck and landed as soon as possible. A predisposition to the disease appears to be caused by fatigue, especially when combined with exposure to the sun; by the immoderate use of alcohol, and by insufticient or improper food. No prophylactic medication is known to be of value. Various methods of preventive inocula- tion have been devised, notably by Freire and Sanarelli, but experience has shown these to be without effect. DISEASES DUE TO INTEMPERATE OR IMMORAL HABITS. ALconHoLisM.—The attitude of the soldier toward the use of intoxicants is largely determined prior to his en- trance into the military service. That the majority of such soldiers as actually become drinking men after en- tering the army, do so as a result of social environment, cannot for a moment, however, be doubted. To drink and ask the companionship of others in consuming alco- holic beverages is the first step toward the development of the drunkard in the army, asin civil life. The idea that social superiority attaches to an ability to consume large quantities of alcoholics still exists to a certain ex- tent among a few soldiers of a lower class: and by such, a novice in the art of drinking may be assailed with ridi- cule and contempt. Such men are largely responsible for the idea which sometimes prevails among recruits that a physical tolerance of alcohol is an essential at- tribute of the seasoned soldier, and that only he who is able to imbibe his share of intoxicant without apparent effect has demonstrated his fitness to enter upon the pro- fession of arms. Besides the above class, a number of soldiers undoubtedly acquire the habit of alcoholism through favorable opportunity, particularly if they are men without aim or purpose in life beyond the per- functory accomplishment of routine duties; men who are possessed of no internal resources for their amuse- ment, and to whom the normal military existence is burdensome, dull, and monotonous. A certain class of susceptible individuals appear to be markedly influ- enced in their use of alcohol by atmospheric conditions, and excessive heat, cold, and moisture have been ob- served to develop a latent desire for drink on the part of soldiers which would probably otherwise have remained dormant. A small number of periodical drunkards are true degenerates. Without apparent cause, in the face of promises and protests to the contrary and in spite of inevitable court martial, disgrace, and punishment, alco- holic excesses are begun and continued until exhausted nature brings the debauch to a close. Then follow deep contrition and humiliation, renewed and earnest prom- ises of reform, and an apparently sincere attempt to repair the damage done to health and character; a period of steady habits, and again a sudden plunge into alco- holic excesses. A large proportion of inebriates, how- ever, as found in the military service, are men of unstable mental equilibrium, indecision, and weak character. Such, under any conditions out of the ordinary, find the mental strain beyond their power of endurance and promptly seek relief in the nerve-benumbing effects of alcohol. Frequency of Alcoholism.—In the army the abuse of al- cohol is one of the most potent factors by which military efficiency is impaired; and in the past drunkenness has been largely looked upon as a distinctively military fail- ing. Its influence, as well as its prevalence, however, is indifferently shown by statistics. All alcoholics do not enter hospital, and a certain proportion succumb to other affections, as gastritis, cirrhosis, and nephritis, in the occurrence and ultimate result of which the use of intoxicants may have played no minor part. Further, the term alcoholism includes many pathological condi- 603 Camp Discases, Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tions and their symptoms, these varying according to the quantity of alcohol taken and the frequency with which it is consumed. Chronic drunkenness occurs chiefly among old soldiers; and this class is naturally not pro- portionately represented on the sick reports as compared with younger men, among whom the use of intoxicants more frequently occurs in the nature of periodical ex- cesses. Acute alcoholism not rarely terminates life, and even at as recent a period as the decade 1886-95 it stood sixth in order of importance in determining the annual mortality among white troops. The proportion of dis- charges and constant non-efficiency from this cause is, however, at all times low. The amount of alcoholism in our service has steadily decreased in the past fifteen years; this having been ac-. complished through greater care in the selection of re- cruits, a growing sentiment in favor of temperance in the social class from which the soldier is drawn, greater efforts on the part of the authorities for the elimination of in- ebriates from the service, and, finally, through the estab- lishment of canteens, the favorable influence of which is discussed subsequently. The following table shows the prevalence of alcoholism in the military forces of the United States during the thirty years of peace 1868-97, inclusive: Aoan Number of cases Number of cases Year. ae 5 th admitted to hospitaljof delirium tremens SLND ayaa per 1,000 strength. | per 1,000 strength. 47,472 32.59 35,221 37.70 31,831 38.20 29,430 45.80 26,844 47.50 7,909 49.40 27,021 58.10 23,575 68 24,886 64.50 23,707 59 23,381 59.40 23,964 65.10 24,004 61 23,222 57.60 23,239 68.70 23,489 66 24,034 2.10 24,188 53.50 1.57 23,572 42.80 1.01 23,841 46.70 24,726 40.20 92 25,008 41.40 51 24,234 40.7 86 23,269 40 90 24,203 37.20 7 25,287 33.80 55 25,376 30.90 82 25,204 30.10 83 25,119 28.80 39 25,417 27.80 58 In 1898, during the war with Spain, the admission rate fell to 15.1; the more active operations and novelty sup- plying much of the desired excitement, while the unusual conditions undoubtedly attracted a superior and more temperate class of young men to the colors. ADMISSIONS FOR ALCOHOLISM AND ITs RESULTS, PER 1,000 StRENGTH, 1885-97. Year White Colored Total for ‘ troops. troops. the army. ASS: :. «ic taetaareamactesp tee eteteatese 59.00 4.00 54.00 1886. '..c lemcneraceeateconee stele ete otaen 50.21 4.67 7.09 TSB; sca cieciinbinna cnaeeinereG@aatite 50.88 2.23 46.31 S88. isco catestetie titetemeete aeiecien 43.97 4.55 40.12 1889; .)./ ccs einee’e since chine cieealee ce 45.64 2.07 41.43 1890. icccnials seme sirente mole metuteoes 44.45 5.59 40.73 ASOL; ciccasssaca bina eatontteters ttamoteteleaies 44.19 3.39 40.01 1802: LFemeeionacewiom ee cieetiels ore 41.19 8.85 37.23 * L8OBS. Bice decison ecmttinces tees 37.23 7.47 33.97 18Q4; cide seals etasasisichet sees 33.79 4.79 80.94 1895.0 tetas pcaloid nowlenmuecicenseer 2.16 6.47 30.11 Ifo! URE UMMan A hambadoendiauso0s 31.20 5.70 29.06 DSO. 55 Sica ae oseleuetne we eietoores are 30.02 4.62 27.86 Decade 1886-05. For ikissctiee sens 42.37 4.89 38.69 * * Including Indian soldiers. 604 The remarkable difference existing between the white and black troops of the United States service as regards the prevalence of inebriety is illustrated in the preceding table—statistics which cover extended periods and which show that there is approximately only one-tenth as much alcoholism among the negro regiments as among the white troops. Few colored soldiers are hard drinkers, and as far as beer and other malt liquors are concerned, there apparently exists a racial distaste for these bey- erages. It is well recognized that where negro troops replace white soldiers in a post, the canteen profits from beer and wine are greatly diminished while the sales of cigars and confectionery are proportionately increased. This racial difference as regards the use of alcoholics is further shown by statistics for the British army cov- ering the European and non-European troops in the West Indies. For the year 1897 the admission rate per thou- sand strength, for the former class, was 15.6, while the death rate was .74. For the native (negro) troops dur- ing the same year the admission rate from this cause was .6, while the death rate was nz. As to the amount of drunkenness existing in foreign ser- vices as contrasted with our own, no accurate comparisons can be drawn, from the fact that abroad none but the se- vere cases of alcoholism appear on sick report. Drunken- ness, however, is fairly prevalent in England and Ger- many—much less so among the Latin nations, who are comparatively free from alcoholic excess. In France, where absinthe is much employed, the rates are said by Laveran to be only about one-tenth as high as in the Eng- lish service, and Viry states that for the fifteen years 1875— 90 the deaths from the use of alcohol in the French army amounted to only 11.5 annually, a considerable proportion of these occurring in Algeria. In Italy and Spain the rates are even lower than in France, and during the oc- cupation of territory by our troops as a result of the late war, it was a matter of frequent comment that an intoxi- cated Spanish soldier was rarely, if ever, seen. In both the British and French services the amount of alcoholism is much greater among troops serving in the colonies than among those at the home stations. Influence of Alcohol on Military Efficiency.—The effect of moderate drinking in the production of an increased amount of sickness is well illustrated by the data col- lected by Carpenter relative to British troops serving in India, based upon 17,334 moderate drinkers and 9,340 abstainers. Of the former class he found that 1 out of every 7.28 soldiers was admitted to hospital, whereas of the latter group but 1 out of every 14.47 was so admitted. Still more favorable to the abstinence class are the figures for the average number of days spent in hospital; the moderate drinkers losing 102 days per thousand as com- pared with an average for the abstainers of 36.4 days. According toan editorial in The British Medical Journal, the admissions to military hospitals in India, during the year 1891, amounted to 5 per cent. for abstainers and to 10.4 percent. for all others. Madden states that in three benefit associations in England, during the five years 1884-88, there were lost by each laborer 26.20, 24.68, and 27.66 weeks through illness—an average of 26.18 weeks: while during the same period, in the “Sons of Temper- ance,”. which admits only total abstainers to membership, the average number of weeks lost by each mem- ber were 7.48—less than one-third the rate given in the other organizations. As to the actual effect of alcohol upon the death rate, it is obvious, as already remarked, that military statistics furnish little information on this point, since only acute cases of intoxication are noted on the records. Chronic alcoholism, however, while it cuts no figure in military statistics, imparts a peculiarly grave character to all dis- eases occurring in drunkards, and does much, through the organic changes, local congestions, and nervous de- pression which result from the continued use of intoxi- cants, to bring about a fatal termination in any serious. affection. Alcohol is one of the most frequent causes of insanity and suicide in the military service. In civil life some: ——— . REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Camp Diseases, Camp Diseases, writers attribute two-thirds of all mental diseases to alco- hol, and it is said to be the chief cause of self-destruction in England, Germany, and Russia. According to Mad- den, in the years 1878 and 1879 it was found that in 27 per cent. of all male lunatics in the asylums of Germany the mental condition could be directly traced to the use of alcoholics. In Austria, according to Gauster, 40 per cent. of insanity occurring in males could be ascribed to alcoholic excesses. In our military service no figures as to the influence of inebriety upon insanity are available; but for the seven years 1887-93, out of 134 suicides oc- curring during that period, alcoholism was officially re- ported as being the cause in 31.3 per cent. With regard to the use of alcohol upon marching troops Rosse states: “The experience of the Ashantee War in 1876 shows that alcoholic drinks are hurtful. The men who did not touch the supplementary ration of rum pre- sented a mortality and morbidity inferior to the other soldiers.” This statement will be supported by all who have served with troops on campaign. As to the effect of drunkenness upon military morals and the maintenance of discipline, no argument is re- quired to show that the infractions of discipline are largely the result of alcoholic stimulation. It was noted of the British troops in India, in 1891, that of all minor offences 1.5 were committed by abstainers to every 6.7 committed by moderate drinkers. As expressed by Smart, “the medical.and court-martial records after pay day, in all camps where whiskey can be procured, fur- nish data sufficient for insistence on its exclusion as the cause of much disease and many injuries and accidental deaths.” As summed up by Parkes: “When debarred from spirits and fermented liquids, men are not only better be- haved but are far more cheerful, are less irritable, and endure better the hardshipsand perilsof war. The cour- age and endurance of a drunkard are always lessened; but in a degree far short of drunkenness, spirits lower, while temperance raises, the boldness and cheerfulness of spirit which a true soldier should possess. If spirits neither give strength nor sustain it against disease, are not protective against cold and wet, and aggravate rather than mitigate the effects of heat; if their use even in moderation increases crime, injures discipline, and im- pairs hope and cheerfulness; if the severest trials of war have not been merely borne, but most easily borne with- out them; if there is no evidence that they are protective against malaria and other diseases, then the medical offi- cer will not be justified in sanctioning their issue or their use under any circumstances.” Woodhull adds: “It is not necessary to insist, from theoretical or medical grounds alone, upon the mischief that alcohol causes soldiers. The observation of any offi- cer of experience is enough. Liquor, besides weakening men physically, tampers with their will power, disturbs their temper, makes them less trustworthy even when sober, is at the bottom of almost every violation of disci- pline, and is the one agent that can convert a regular force intoa mob. The absence of liquor usually means a clear guard-house. Abundant liquor means a heavy sick list, a large guard report, and a general feeling of doubt as to the command. It follows without saying that if the use of alcohol is hurtful in a personal and in a martial sense to the private soldier, who is the lowest unit in the military scale, it is very much more mischiev- ous in its ultimate consequences when an officer, who is so potent with those beneath him, is its victim.” For the United States service the discussion of alcohol- ism would be incomplete without reference to the can- teen, which, more than any other one factor, has brought about a reduction in drunkenness and its results. This institution, officially known as the post exchange, had its origin in our service at Vancouver Barracks in 1880, but it was pot until February, 1889, that the insti- tution was recognized by the War Department, and rules and regulations for its establishment and government published to the army. The purpose of the army canteen, as officially an- nounced, is to supply troops with goods at a low rate of profit and to afford rational recreation and amusement to all enlisted men. The sale of ardent spirits is strictly pro- hibited therein; but commanding officers are authorized to permit light beer and wine to be sold by the drink, on week days, in a room set apart for the purpose, when in their opinion such action is promotive of temperance. Gambling of any character is forbidden. Each canteen is managed by an officer selected by the post commander for his fitness for the position, he being allowed one or more enlisted men as assistants; under recent orders civilians only being allowed to serve as barkeepers. As showing the favor with which the system was received, it is only necessary to say that in 1894, five years after its inauguration, there were 75 canteens in successful opera- tion, and that during that year the total receipts were $1,417,079.62; of which sum no less than $304,649.91 were returned to the men as dividend profits. The effect of the introduction of the canteen system upon the rates for alcoholism was prompt and marked. For the decade 1878-87 the average number of admissions for alcoholism and its direct results amounted to 64.28 per thousand of white troops. This rate diminished dur- ing the next ten years in proportion as canteens were gradually established at various posts, omitting frac- tions, in the following ratio: 44, 46, 44, 44, 41, 87, 34, 32, 31, 30. On observing the admissions for alcoholism for the seven years 1885-91 which immediately pre- ceded the general establishment of the canteen system upon a satisfactory basis, it is found that a yearly aver- age of 1,214.8 men found it necessary to apply for treat- ment from this cause; while for the six years 1892-97, after canteens had been generally instituted throughout the army, an average of only 928.4 men annually re- quired attention for this reason—a reduction amounting to 23.6 per cent. In 1890 there were 17 posts at which the admission rate for alcoholism exceeded 10 per cent. of the strength. In 1891 the number of such posts had decreased to 11, and in the six subsequent years dimin- ished at the following rate: 10, 7,4, 5, 2, 2. This favor- able showing for the army at large was duplicated in the case of each individual post, the introduction of the can- teen failing in no instance to be promptly followed by a diminution of alcoholism. For certain stations this im- provement was extraordinary. In 1889, Willet’s Point had an admission rate for alcoholism of 222.97 per thou- sand. In 1890, the year when the canteen was estab- lished at that post, it fell to 157.50, and in the next year amounted to only 70.46. At Fort Spokane the amount of sickness resulting from intoxicants was reported by the surgeon as having diminished 50 per cent. during the six months following the institution of the canteen. At Fort Douglas, in 1888 and 1889, the total number of ad- missions attributed to alcohol amounted to about 85 per thousand strength; while during 1892-94 this rate fell to 52.95 per thousand strength; and such instances might be multiplied many fold. As to the’value of the canteen in the tropics as well as at home stations, in reducing alcoholism, all are agreed. A report by O’Reilly upon the condition of the British troops in Jamaica states that the canteen, from which the men can always procure beer, has been largely instru- mental in the disuse of stronger spirituous liquors and in a lessening of the evils which followed the free use of spirits in the tropics. In referring to the condition of the Fourteenth United States Infantry at Manila, Cardwell ex- presses his belief that a great improvement shown in the figures for venereal disease and alcoholism in this regi- ment was due to the establishment of a canteen, kept un- der admirable discipline; and he adds: “Cool American beer as a substitute for the ‘ beno’ of the native gin shops has a most beneficent effect.” The cases of delirium tremens will be accepted by all as furnishing reliable data by which the gravity of the admissions for alcoholism may be determined. It is, therefore, of interest to observe that, for the seven-year period above noted prior to the complete adoption of the canteen system, the average annual admissions for this 605 Camp Diseases, Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. cause, actual numbers, were 23.8; while for the six-year period of peace following the establishment of this sys- tem the average number of men admitted vearly for de- lirium tremens was 16.6, a reduction of 31.3 per cent. in this serious class of cases. It can scarcely be doubted that this remarkable decrease was chiefly influenced by the substitution of beer—a milder beverage, which rarely produces such effects—for distilled liquors, whose free use is well known to result in great mental excitement and nervous exhaustion. It isrecognized that alcoholism and insanity are closely related through the direct influence exerted by intoxi- cants in the production of mental aberration. Hence it is not surprising to find that theaverage number of cases of insanity annually coming under treatment was 35.1 for the seven-year period 1885-91, prior to the complete establishment of the canteen system, and only 24 as an annual average for the six subsequent years, 1892-97. These figures show a reduction in insanity amounting to 31.7 per cent. As to the number of days of service lost annually from insanity, the improvement since the insti- tution of the canteen is even more marked. Figures for the years 1885 and 1886 are not available; but for the five-year period 1887-91, the average number of days lost was 1,568, while for the six years 1892-97 the service annually lost to the government from this cause amounted to only 924.5 days—a decrease of 40.9 per cent. The canteen—for the maintenance of good order in which a commissioned officer is held responsible—is an aid to discipline as well as to the health and morals of troops. It provides a resort which, while under thorough military control, offers inducements to the men to remain at home and spend their idle time within the limits of the post; this condition obviously being far preferable to the one formerly existing, when the nearest and most generally patronized places of amusement and refreshment were the grog shops, usually with brothel annexes, which marked the limits of each military reservation. Except with the most dissolute class of men, the soldier is well satisfied to patronize the canteen to the exclusion of outside saloons; knowing, as he does, that he receives good value for his money in articles of excellent quality, and fully appreci- ating that the profits of the institution ultimately accrue entirely to his benefit, and are not, as is the case with outside establishments, diverted to the advantage of others. Besides the congenial resort which it furnishes, the influence of the profits of the canteen in promoting contentment among troopscan scarcely be overestimated, contributing as they do to improvement of the food, to the attainment of wholesome amusement, and to the provision of much by which the soldier’s life is made less irksome and he himself rendered more efficient in the performance of his military duties. The best index of the content- ment of ,troops is to be found in the rate of desertions, since it is obvious that the soldier who is well satisfied with his lot will not endeavor to escape from the per- formance of his military obligations. That the canteen system has, from this standpoint, operated to the general welfare of the men is undoubted, the desertions and percentage of desertions in the regular army, from 1885 to 1897 inclusive, being as follows: 2s a} re or! s w ot tires) od (=| o055 =| Year. | £2 5 5 Year. | & 2 5 5 Suet bine 3 5 B Paulas 5 <¥ A a 4% a) a 1885 24,816 | 2,626 10.6 1892 24,869 | 1,410 5. 1886 24,365 | 2,012 8.3 1893 25,670 | 1,682 6.3 1887 24,488 | 2,525 10. 1894 25,661 926 3.6 1888 24,790 | 2,678 inh 1895 25,209 | 1,34 5.3 1889 25,564 | 2,730 ine 1896 25,148 858 3.4 1890 24,980 | 1,922 Ae 1897 25,300 726 2.9 1891 24,525 | 1,398 5.7 | Average for seven years Average for six years before canteen system after canteen system was thoroughly estab- was thoroughly estab- lished i 4Atas senile 9.18 USHOG pc saps asses overs 4.53 606 From the above table it is observed that during the first year after the canteen system was authorized the rate of desertions fell 26 per cent., while during the next. year, as the system was more generally established, the rate was further reduced to 49 per cent. For the five years previous to the establishment of the first officially recognized canteen the number of men annually desert- ing from the service, per thousand strength, amounted to 101; while for the eight years immediately subsequent. to the institution of this system the annual number of desertions was reduced to 50 per thousand strength. The decrease noted has been practically progressive, and for the two years immediately prior to the war with Spain scarcely one-fourth the number of men, as com- pared with the three years immediately prior to the in- troduction of the canteen system, found the military ser- vice so uncongenial as to desire to escape from completing their terms of enlistment. These results are certainly most gratifying, and there is no reason for believing that. with the development of the canteen along its legitimate lines of growth a still further decrease in the present. small rate of desertions may not be confidently antici- pated. Drunkenness is certainly prevented by the constant military supervision to which the canteen is subjected. The men themselves are usually careful not to indulge in alcoholics to the point of inebriety; while such few individuals as are inclined to be forgetful of the dangers. of excess are usually restrained by companions, or by those connected with the canteen, from passing the bounds of actual intoxication. Should such a condi- tion actually result the drunken individual is rarely left. to his own devices or permitted to become offensive, but is usually prevailed upon by others to return to barracks without committing any breach of discipline. Hence, brawls and disturbances, with resulting court. martial, have, since the introduction of the canteen sys- tem, become relatively infrequent, and pay day, formerly synonymous with debauchery and riotous disturbances, is now scarcely to be distinguished by its effects from any other day. As illustrating the marked reduction of con- victions for drunkenness and for complications arising therefrom, since the establishment of the canteen, the fol- lowing figures, from the reports of the judge advocate general, are of interest: Total number of |Nusmhert rials and Trials ani Year. convictions in the ip rapeieepse Brily. arising therefrom. TSBO"eertasearnetaletiatn otele steals 1,640 842 I tee) Gain cardamone sun dicoccae 1,730 289 WSSR satetarctenrrela caro staceiecuts Reticnes 1,999 357 BRO inreletesalsvoerisiaias vista as 1,752 423 TSO0 Ree tericke ohametneneaeacs 1,907 407 phot) Ron Renee met G Seire: 2,000 47 TL BOR eprarahers (elec etmaisve er atecata eva 2,198 228 SOS S fersssorsclous’s au saetactnasiee 2,189 163 SOE 2 Be cathe eect ednasanes 1,728 120 WBQD Sica veeterarecsielstereicronteiacretas 1,486 142 WBOG i. B inte ciet ehets sesve reels oid etieisine 1,384 168 DOO a oo rctens tye shayetate situa rains, oe 1,245 143 Average for the six years N886=O1G eke ttinaeeita edhe core 1,838 372.5 Average for the six years TSQZ=O7 cee roisa yates anwar 1,605 160.6 From the above figures it is evident that coincident with the thorough establishment of the canteen system there has occurred a decrease, amounting to considerably more than one-half of the drunkenness which formerly tended to the impairment of discipline, to the demoraliza- tion of individuals, and to the occurrence of assaults, in- juries, and deaths. It is idle to deny that this excellent result has been largely due to the attraction furnished by the canteen, combined with the military discipline which prevails in that institution and which reduces to a minimum the possibility of dangerous alcoholic excesses. The opportunity given the men of purchasing light, : REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. nutritious lunches in the canteen is also certainly of much benefit. Many articles of food not obtainable in the company mess are thus brought within reach, and the monotony which often pertains to company cookery may in this manner be agreeably interrupted. It is probable, too, that this feature does much to prevent the intem- perate use of alcoholics. The gastric cravings of hearty and idle men are thus satisfied, and a sandwich with the beer largely decreases the desire for an additional quan- tity of the latter. It is claimed by the advocates of total abstinence that through the sale of beer in the canteen the health and morals of the soldiers are impaired ; that such tacit encour- agement on the part of the government favors indulgence in alcoholics, and that drinking habits are thus formed by those who might otherwise have remained sober men. These objections are purely theoretical, and are at vari- ance with facts as observed since the establishment of the canteen. The sale of beer, under suitable restrictions, un- 10 20 30 40 50 60 70 80 90 10 20 80 40 50 60 70 80 90 Camp Diseases, Camp Diseases, brings with him into the service the result of the moral moulding to which he has been subjected during child- hood and youth in civil life, and does not change his nature or moral standards concerning alcoholics with the mere donning of the uniform. The vice of drunkenness is certainly no longer either directly initiated or aggra- vated as a result of military service, and if the opinions held by some are correct as to the moral conditions ob- taining in the army, then its cause must be sought for within the social classes and the conditions of environ- ment from which the human material composing the army isdrawn. It is certain that there has been no more drunkenness to be found in the army—if indeed there has not been less—during the past few years than has occurred in the corresponding classes of civil life. VENEREAL DiIsEASE.—Of all causes, venereal disease is the one which, in time of peace, brings the soldier often- est to hospital and which most affects his efficiency—this being particularly the case in our own service. 400 10 20 30 40 50 60 70 80 90 10 20 30 40 50 60 70 80 90 10 20 30 40 50 aa = oa | UNITED STATES. GERMANY. JAPAN. Biba SS TSS HOLLAND. EAST INDIES. fener mes, Pp Fic. 1092.—Average Annual Admissions, per Thousand Strength, for all Venereal Diseases, in the More Important Armies of the World, for the Three Years 1890, 1891 and 1892. doubtedly results in good rather than in evil to the troops at large, and may properly be looked upon as a safety valve for those accustomed to regard the use of a certain amount of liquoras both harmlessand proper. Compar- atively few men to-day become inebriates through a taste for alcoholacquired in the military service ; and while there are a certain few individuals who may imbibe too much beer on pay day, they constitute a class which, in the ab- sence of a mild beverage of this character, would probably resort to stronger—and frequently sophisticated—liquors outside the limits of the command. That beer-drinking, viewed in the abstract, is unproductive of good, will be ad- mitted by all; that, when properly controlled, its sale in canteens, rather than its prohibition, redounds to the gen- eral health, morals, and military efficiency, few, ifany, who are conversant with the subject will attempt to deny. It is certainly unfortunate that the temperance element in civil life, which is so constantly endeavoring to enact legislation against the sale of alcoholics of any character in the military service, cannot be brought to regard the matter from tic practical rather than from the sentimental aspect, and thus assist in controlling and largely curtail- ing an evil which it is powerless to prevent, but which, if its efforts toward restrictive legislation should be suc- cessful, would undoubtedly be greatly increased. It may here be remarked that the view is commonly entertained by the civilian class just mentioned that the sol- dier is a sinner above sinners and requires special legisla- tive measures to safeguard him against his weakness—the fact being wholly ignored that the army is recruited from the general community, and merely reflects the qualities of the latter, whether they be good or bad. The recruit The following table shows the ratio of admissions per thousand strength for all forms of venereal disease in the principal armies of the world, compiled from the most available and reliable data: S ae = = oo , ah = RITAIN. $|s|Es| g #5} 2 | £3 |———~ vera |B} 8a) 8] & jee) es) es) 2) a oO iF 3 3 =| Pm = Bees Neves ee aot oS So ge bby | ne apa eaeed Mer Bere lieaten! kets ea hoe 202.2 | 191.0 ISTBS |lesse een Oo ale wee, Noieeed|| LOL 167.6 | 181.6 1874*|.... | 38.4 | 53 easels We iia carestnoeeD 145.7 | 207.5 ASTD Sines O10 1/59 ee elite ceuler cane LO: 139.4 | 213.5 1876 | 57 28.8 | 65.8 ee cal chistes | seen 102.6 146.5 | 203.5 187 57.8 | 30 |66.9 |. mates cree Wiese lao 153.2 | 224.4 187 59.7 | 36 | 754+]. Bete ell Ue seul een | MeL) 175.5 | 291.6 187 63.7 | 38.5 | 81.4 fe PE al | yeteae esepc haa 179.5 | 253.3 1880 | 65.8 | 84.9 | 75.7 tas. dete eaarcve | dost: 245.9 | 249 1881 | 60.6 | 89.2 | 79 Caec a leien lieeret | oOLc8 le4.bsl' 259.6 1882 | 62 41 73.7 Sree, lncealaullias cal: dock 246 265.5 1883 | 58.9 ; 38.2 | 73.3 Hees Neral eon | obit: 260 | 271.3 1884 | 52.1 | 34.5 | 73.5 eae Uineon waleete | eee 270.7 | 293.5 1885 | 50.7 | 32.6 | 69 Soot eat etietes | ae 275.4 | 342.6 1886 | 49.6 | 29.7 | 65.8 Bee Hive ties sO. Wi eOr bel ooo.s: 1887 | 51.6 | 28.6 | 64.4 47.5 |.... | 389.8] 74.87 || 252.9 | 361.4 1888 | 46.7 | 26.3 | 65.4 | 42.4 | 76.5¢)].... | 29.7 | 80.88 || 224.5 | 372.2 1889 | 45.8 | 26.7 | 65.3 | 40.7 | 66.6 |.... | 24.7 | 84.66 || 212.1 | 481.5 1890 | 43.8 | 26.7 | 65.4 | 43 73.4 | 96 27.38 | 75.22 || 212.4 | 503.6 1891 | 43.7 | 27.2 | 68.7 | 41.5 | 71.5 | 60.4 | 37.5 | 72.46 || 197.4 | 400.7 1892 | 44 27.9 | 61.6 | 44.6 | 69 53.1 | 36 76.73 || 201.2 | 409.9 1893 | 42.8|....| 64.5 | 48.1] 93.38 |45.8]....| 73.8 || 194.6 | 466 1894 | 40.9 64.8 2 54.3 80.40 || 182.4 | 511.4 best tial | Ree te bs 84.8 | 48.1 73.70 || 178.8 | 522.8 *In the case of Germany, 1873-74, 1874-75, and so on. + Bosnia and Herzegovina were occupied in this year. + Compulsory examination of prostitutes abandoned. 607 Camp Diseases. Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Among European armies Germany has by far the low- est rate. Russia and France come next, then Austria- Hungary,sthen the home army .of Holland, then Italy. No continental army included in the above comparison has so high arate as that shown by the United States army—and with us, moreover, the actual prevalence of venereal disease, through its concealment to a consider- able extent by the men, is probably greater than the re- turns indicate. The small amount of these diseases in the army of Japan is noticeable. In all the above armies, with the exception of those of Great Britain and the United States, some special regula- tions are in force for preventing the spread of venereal disease. These generally consist of weekly or fortnightly examination of the men for the detection of venereal dis- ease, non-commissioned officersand married men being in some services exempted, together with registration and periodical examination of all women ascertained to be leading a life of prostitution. In the Italian army, reg- ulations of this latter kind were relaxed in 1888. In the case of most of the above armies the comparison may be carried into further details as follows: MEAN ANNUAL ADMISSION RATE PER 1,000 FOR THREE YEARS, 1890-92, DUTCH BRITISH Es TROOPS. || TROOPS. | 3 . Bie ae SHELIA ee a| 2|a a Hog 3 =i Fl s/#/S|e/8s\| 2) 4 | 58 D H 2 Ss ols ) = mo) es) es) eS |e oi a] & Primary and secondary 1 SYPHILIS) ccc cre cca. 5.5} 9.0]13.1]18.9)14.8) 47.0}|101.7/175.4/16.83 All other venereal dis- CASES oc duroc eeu totes 21.8)34.9/29.9/57.4/55.0/408.6]|101.9]262.6)/57.96 In these three years, then, the German army had scarcely more than one-thirty-second, and no European army had as much as one-eleventh, of the amount of syphilis which devastated the British troopsin India. The Dutch troops in the East Indies, with an exceedingly high rate of vene- real disease generally, did not suffer from syphilis one- third as much as did the white soldiers of the British In- dian service; in which the rate has risen rapidly since the period included in the above comparison, while at the same time it has materially declined in the Dutch East Indies. Syphilis.—Figures with regard to syphilis are of par- ticular importance as directly bearing upon the military efficiency of an army. The disease, even at best, seri- ously undermines the constitution and renders the soldier at all times less resistant to invasion by acute disease and to its fatal termination. Even in many cases ultimately returned to duty, the men have frequently been in hospi- tal for considerable periods and are prone to later mani- festations from a temporarily latent infection. In such instances the state has not only paid the man for the time he was unfitted for duty, but receives back a doubt- fully efficient soldier, extremely liable to break down under the fatigue and privations of field service. The prevalence of constitutional syphilis in the United States army, during the past thirty years, has been as follows: Admissions to hospital per 1,000 strength. Admissions Year. to hospital per Year. 1,000 strength. HY NWWWHDDS BERR ESF SRERNESS ORR oo During the year 1898 the admissions for this cause were only 10 per thousand. As is seen by the above figures, syphilis has apparently diminished, during the past thirty years, to one-tenth of the amount existing in 1868. While it is probable that a certain proportion of this reduction is due to a more ac- curate differentiation between the hard and soft venereal sores, the fact nevertheless remains that the reduction in syphilis has been not only great but steadily progress- ive. In the various armies on the European continent the tendency appears to be rather toward a reduction than an increase of syphilitic infection; butin the British army at home, and particularly among the British troops in In- dia, a serious feature of recent years has been the dispro- portionately great increase in the amount of primary and secondary forms of this disease. This growth was not great prior to 1884, when the Contagious Diseases Act was revoked, but since that time the advance has been so extensive and rapid as to be appalling. In the follow- ing tables the rapid development of syphilitic disease among the British troops in India is well shown; though figures for primary syphilis cannot be given for the period prior to 1887, as the hard chancre was not re- quired to be differentiated from the non-syphilitic sore until that year, and then only in part: SECONDARY SYPHILIS, RATIO OF ADMISSION PER 1,000 STRENGTH. Bengal figures— 187 T apis .ecoidsareshasiusteeetioe 22.1 TSGT cove aie chain pie staveletare o\epere'e 23.7 L878 34 sic steinastomtaetonen 22.1 1868 wud release partesic we btes 25.4 18%9', o iaceazasanase stein 24,1 VSCOM NR Sean carne te ete 23 1880) 3. oe seen ceemaees 23 ASTON. il fea todas eeitdeee 25 1881 5.0.05..aRe Seto 23.1 AST esate mmetometecetente 24.2 1882 «+ sis sislelelsolateresanreterae 23.2 IBF. Getta tecneoloe oeatael 22.8 1888. oe lass sis:a eraurereieatefereete 23. All India— L884 Sots cite vrneelont een ete 1BI2 Fo eas encase tdens 22.4 Mean for years 1872-84.. 23. 3 Dy GRAB CHOIR Torniciact7 20.4 885.5 oviss vioiod Sere eee 28.7 DSTA: costar tisteconcrstocmatereraranerete 25.2 1886. «:s\cierete. cereale ee 33.3 ISTD oo sretupicieretomeenincienec 25.1 1887 ciieies some b eeeteeee 29.4 AST Grca Meroe: ihcertaeaees 23.9 Primary | Secondary Primary | Secondary Year. | syphilis. | syphilis. Year. syphilis syphilis. 188i ene 75.5 29.4 1892..... 102.6 57.8 1888.... 72.1 82.4 ite Sea ae 129.3 61.6 1889.... 134.3 51.2 1804s ire 173 74.6 1890.... 135.6 66.3 1895 ene 174.1 84.9 1801 nee 104 60 In 1898, of the British troops in India, venereal disease caused 466 admissions per thousand strength. No less than 2,619 men, or equivalent to more than two regi- ments, remained constantly in hospital throughout the year from this cause. Each case required treatment, on an average, for thirty days, and the average rate of non- efficiency for each British soldier in India was twelve days lost. The admissions for syphilis alone were 275 per thousand. Of 70,642 British soldiers serving in In- dia on the 15th of July, 1894, 19,892, or 28 per cent., had been admitted to hospital for syphilis since their arrival in India; and only 26,247 men, or 87 per cent., had never suffered in or out of India from any venereal disease. Of the 13,000 soldiers who returned to England from India in 1894, over 60 per cent. are reported as having suffered from some form of venereal disease. In 1895, an average of 45 men per thousand, or 8,200 of a total force of 71,- 031 British soldiers in India, were constantly in hospital for venereal disease. But these figures by no means rep- resent the total amount of inefficiency due to this cause. Many cases of secondary syphilis, in the British service, have in the last few years been treated by hypodermic injection of mercury without admission to hospital, and do not, therefore, figure in the returns; while a large number of men who have been discharged from hospital as nominally cured are fit for service only under peace conditions. Among 5,822 men detailed for field service with the Chitral relief force, 462, or nearly 8 per cent., had to be rejected, prior to m'litary operations, for exist- ——— ee REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ing venereal infec- tion; 279 more, or an additional 4.5 per cent., had subsequent- ly to be transferred from the field hospi- tals to the base for the same cause. On a basis of 8 per cent. rejected before start- ing on field service, and 4.5 per cent. more subsequently invalided for disease contracted before crossing the frontier, 8,880 men out of the total British In- dian force of 71,031 ae AAS eA Guida we eis 106 Uh 1 i a a Camp Diseases, Camp Diseases, would have to be put down as useless, from sestestant FEES esa ceaneet this one cause, for field operations. The report of the Depart- mental Committee says: “In 1895 vene- real disease attacked the British troops in India to an unprece- dented extent. Out of the enormous total dy 7 a PH ] cr] ae - eit TS of 522 cases of vene- real per thousand troops, syphilis con- tributed nearly one- half, ¢.e., 259 cases per thousand, a figure many times greater than the high- est of which we can find any record in the statistics of continental armies for recent years either at home or abroad. Venereal disease caused more than one-third the total amount of sickness from all causes, the constant dis- ablement of 3,200 men out of a total force of 71,000 and a vast amount of partial disability and unfitness for any but routine duties.” In the mountain campaign of 1897, it is stated that out of an actual strength of 16,600 British troops on active service, 492, or 3 per cent., were incapac- itated during the campaign from venereal disease. The 16,600 troops in the field were drawn from a force of 21,489 men. Of these, 989 were rejected as unfit for ac- tive service on account of venereal disease. Hence 1,481, or nearly 7 per cent. of the total strength, were disquali- fied for service through this cause. As illustrating the constantly increasing proportion of venereal diseases, among British troops in India, as com- pared with all affections of a non-venereal character, the following figures are of interest: India, 1860-95. only); 4, secondary syphilis. MEAN ADMISSION RATE FOR NON-VENEREAL DISEASES. Ratio of Ratio of ; venereal to venereal to Year. Per 1,000. | non-vene- Year. Per 1,000.| non-vene- real admis- real admis- sion rate. sion rate. Bengal : Per cent. India: Per cent. 1860-64. 1,606 18. 1890.. 1,016 49.5 India : 1891... 978 40.9 1872-76 aly ie 1892. 1,107 37 eg AGODe 3009 35.8 1893. 949 49.1 aaah 1,010 36.8 1894, 997 51.3 1880...../s,. 1,017 47.3 1895. 940 55.5 In this service, also, the present greater virulence of venereal disease, as compared with former periods, is at- tested by a longer average duration of treatment and by an increase in the numbers of invalidings and deaths due to venereal disease, as shown in the following table: Vou. II.—39 HH Fig. 1093.—Chart Illustrating the Admissions for Venereal Diseases, per 1,000 Strength, among British Troops in 1, All venereal diseases ; 2, all venereal ulcers, primary; 3, primary syphilis. proper (1887-95 (From report of Royal Sanitary Commission.) Average duration eee hela Ratio of deaths of each case of 4 5 due to syphilis to Year. - + real disease to total venereal disease. number discharred total deaths. Days. Pereite stl tw ren Canes 25.95 3.0 0.1 25.68 ad A 28.39 7.2 Ai} 29.07 6.3 6 29.50 10.9 3 29.01 9. 8 29.82 3.7 5 1804 ce siete 30.77 10.3 A OSs AAD 31.49 15.8 1.5 As showing the extraordinary prevalence of syphilis in the British army as a whole it is of interest to note that, according to Longuet, this disease, in 1888, was fifteen times more prevalent anfong British than among French soldiers; while for the year 1896 the number of constantly sick from this cause, per thousand strength, was 14.22 in the British service and only 1.29 in the United States army. It is probable that there is less syphilis among the sol- diers of the various European nations, excluding Eng- land, than exists among the unmarried male civilians of the same class, since those which appear to be severely infected with constitutional disease are promptly dis- charged from the military service. In the United States service, gonorrheea, in contradic- tion to syphilis, has been steadily on the increase for the past fifteen years; thus showing that there has been no improvement in the morals of the United States soldiers as regards chastity. In 1885, the admission rate for this cause was 37.76 per thousand, while in 1897 the rate was 56.21 per thousand. For the year 1896 the number con- stantly sick from this cause in the British service was 9.15, as compared with 3.22 in the United States army for the same period. In 1890 the admissions for gonor- rheea, per thousand strength, were 27.9 for the French army. oe the latter service, according to Marvaud, venereal 609 Camp Diseases. Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. disease of all varieties has steadily diminished, as fol- lows: Admissions Period. per 1,000 strength. TORO GO shies abet ee Naan tiawis vn seh ee tit eae eee meen 106 TST oO eer cireicte cant cle tia ia cie’nictbis nieve aielertvelelesetare eeieielemte-atale 74 TEC 2O8 ee ak ieee s cole cits tien olore nie ote sala le ceaetetersiatertiete e 5D TSSOSIO rie cities eelaaele daiwa cig cic seiucese scacele baleevelaiels Ste-ctes miners 45 Causes Affecting the Prevalence of Venereal Disease among Soldiers.—The influence exerted by race upon the prevalence of venereal disease is undoubtedly not suffi- ciently appreciated by medical officers. A marked dif- ference in this respect exists even among the various armies of Europe, where similar measures of prophylaxis against venereal infections are in vogue; but it is when the rates for Asiatic forces are compared with those for white troops serving under the same conditions that the greatest difference is observed—this being particularly the case with reference to syphilis. It is undoubtedly true that this latter disease, introduced only compara- tively recently among the white and negro races, commits far greater ravages among those in which it has not long prevailed than among peoples who have acquired a com- parative immunity to the affection transmitted through a syphilized ancestry extending through scores of gener- ations. It appears to be true, also, that certain races possess in large degree peculiar powers of resistance to gonorrheeal infection; a quality long since demonstrated to exist in certain individuals of even the most suscept- ible peoples. The following table, taken from the report of the commission investigating the prevalence of vene- real diseases among the British troops in India, well shows the great difference in the admission rates for Europeans and Asiatics in respect to venereal disease: RATIO PER 1,000 STRENGTH. DUTCH ARMY IN THE 7 ; 2 East INDIES. ENGLISH ARMY IN INDIA. European Asiatic British Native Year. Troops. Troops. Troops. Troops. & |<23| 2 /<25|| & |<83) 2 [<28 a O.2) b o.4 is Ol. B og n rt MN ro mM ae] RN ro L800 Se eGsade 58.9 | 483.9] 11.0 | 248.0 || 201.9 | 503.6 | 18.2 | 41.1 ibe) eee 43 | 442 11.6 | 243.6 || 164 | 400.7 | 16.3 | 37.9 1802 cr iscve sy eo 4f 440.9 9.7 | 223.5 || 160.4 | 409.9 | 17.1 | 39.6 1808 ei eee 4.) 370 8 218 190.9 | 466. 17.9 | 36.4 ABO4 i F acratsindle 37 | 416 7.8 | 191.8 |} 247.6 | 511.4) 17.7 | 32.3 Mean for 5 years} 43.6 | 424.7] 9.6 | 225 195 | 458.3 | 17.4 | 37.5 From this it isseen that, in the Dutch East Indies, Asiatic troops suffer from all venereal diseases slightly more than one-half as much, and from syphilis but about one-fourth as much, as do Europeans. In the British forces in India the native troops do not suffer from venereal disease one- twelfth as much, nor from syphilis one-eleventh as much, as the white troops. It is probable that in India caste feeling helps to deter the native soldier from consorting with the lowest and most dangerous class of prostitutes, but his great freedom from venereal disease can be ex- plained only on the ground of racial insusceptibility. It is of interest to note that while the admission rate for Brit- ish troops in India has more than doubled since 1881, among the native troops there has been no appreciable increase. An inference which may be legitimately drawn from this fact is that venereal disease has not increased to any remarkable extent among the loose women of the country generally, but that among the class with whom the British soldier associates there has been an increase out of all proportion to their numbers directly as a result of such relations; both the native women and the British soldiers presenting rates far in excess of their racial normals. As between whites and negroes the greater resistance to venereal infection lies with the former, probably through a longer exposure to the processes of immunization through heredity, Comparative figures 610 for these two classes in the United States service, for all venereal diseases, are as follows: Admission rate | Admission rate Admissions Year. per 1,000 strength.|per 1,000 strength.| per 1,000 strength Whites. Colored. for entire army. ABB4, coals ctesei 75.00 101.00 78.00 S855 tare pnecen 80.00 76.00 80.00 LOSE. cesta steels chie hi WIlEREa asia 74.37 ASST sates. 72.13 95.98 74.37 ALSBS eee eet 78.08 98.51 80.07 A BBO ere crteteh 84.86 82.75 84 66 L890: Hrs ctor 72.02 105.39 5.21 TBO T Setters 70.64 80.18 72.46 * 180254 asen cas 75.71 86.94 76.72 * SOS reerolt ele tiie 74.94 49.00 73.08 * 1808s vi Siesee a 82.21 47.46 80.43 * 1890 ce. laslvcp 75.57 52.26 73.72 TRG S tisiclaseiers , 80.04 56.53 78.08 ac) eA re 81.80 114.60 84.59 Decade 1886- eid lsietatwieliels 75.89 78.48 76.32 * * Including Indian troops. No satisfactory explanation of the sudden and marked reduction of the admission rates for the colored troops for the years 1893-96 can be offered. The experience of the British in the West Indies shows a higher percentage of venereal disease among colored troops than among white soldiers, syphilis being more than twice as com- mon among the former as among the latter. Another point well worthy of careful consideration is found in the fact that venereal infection, particularly of a syphilitic nature, appears to take place more certainly and to assume a much more severe character when rela- tions are entered into between individuals of different racial characteristics than when both are of the same na- tionality ; the aliens suffering in this respect to a greater degree than the resident population. It would almost seem as if there were localized varieties of venereal dis- ease the product of special environment, to one of which a race might be relatively insusceptible, although at the same time falling an easy prey to the allied diseases pre- vailing among peoples of other countries. Troops quar- tered among an alien but not entirely hostile population almost invariably suffer worse in respect to venereal dis- ease than those at home. In the Austrian army a large increase in such diseases followed the occupation of Bos- nia-Herzegovina in 1878; the French troopsin Algiers are more affected with venereal disease than thosein France, and the same is true toa marked degree in the case of the British troops in India and those of the Dutch in Java. In speaking of the native troops stationed in Bengal, it has been said with respect to venereal diseases that the “Gurkhas, being foreigners, have higher rates than other native troops.” These conditions, however, do not obtain when a command is moving or during campaign. The fol- lowing tables well illustrate the points just advanced: AMOUNT OF VENEREAL DISEASE AMONG FRENCH TROOPS IN FRANCE AND IN ALGERIA, COMPARED. (Admissions per 1,000 strength.) 3 F FRENCH TROOPS IN TROOPS IN FRANCE. ALGERIA. Year. | 2 | 8 3 B g £3 5 G2) 2 ews 3 a | oe 9 Py 3 168.) Ss); Bee eee B 5 os | e a is) hah oi= 1802 ree tadels 8.3 5.6 | 27.4 | 41.3 || 15.0 | 11.9 | 28.6 | 55.5 1808. eee Pre inek 5.8 | 25.38 | 39.5 || 15.0 | 12.1 | 32.5 | 60.6 1804 series etic 74 | 5.2 | 23.5 | 36.1 || 13.2 | 11.4 | 26.6 | 51.2 ADMISSIONS PER 1,000 STRENGTH, FOR THE DECADE 1887-96, FOR BRITISH TROOPS IN INDIA AND AT HOME STATIONS. Disease. British army on | British army in the home stations. India. Primary Syphilis:.2. neces eee eee 59.2 127.5 Secondary syphilis .............. 35.9 62.2 Gonorrhoea .....6+6. BANG tacaore 86.2 176.3 ‘ REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Camp Diseases, Camp Diseases, T AMOUNT OF VENEREAL DISEASE AMONG THE DUTCH TROOPS AT HOME AND IN THE EAST INDIES COMPARED. (Admissions per 1,000 strength.) ' ABROAD. TROOPS AT HOME. European Asiatic Troops. Troops 4 |. 88 4 |.88 a |.ee Year| 3 |252| 3 = e348] a 2 (254) a p icsz| § | & \Ss2|/ 3 | & Sea! & a Sol & os Bol] ta) bol a 1S a? | ae | pe BF so | aa ‘ . 1g7 }| No rieturn's for |! ¢1.8 | 447.7 | 509.5 '| 16.3 | 221 | 237.8 1888 yejars. || 58 | 384 | 487 12.9 | 203 | 215.9 1889 49.8 | 417.6 | 467.4 || 12.6 | 254 266.6 1890 13 83 96 53.9 | 430 483.9 || 11 237 248 1891 18 42.4 | 60.4 || 43 399 442 11.6 | 232 243.6 1892 13.4 | 39.7 | 53.1 || 44 396.9 | 440.9 9.7 | 213.8 | 223.5 1893 10.8 | 35 45.8 || 40 330 70 8 | 210 218 1894 | 13.3 | 41 54.3 || 37 37 416 7.8 | 184 191.8 Climate also appears to influence the prevalence of venereal disease, as well as its intensity and character; a tropical climate appearing to lower the vital resistance as regards invasion by venereal infection, to induce disease of unusually severe type, and to cause, in syphilis, the de- termination of superficial rather than deep-seated lesions. The amount of venereal disease also bears a close relation to the age of the soldiers; young men, and particularly young recruits, being especially liable to such disease. The proportion of married men among the troops natu- rally exerts a marked influence on the occurrence of such affections; figures for the British army in India, for the years 1867-72, showing that the percentage of admissions for venereal disease among married men was one-fiftieth of the percentage for the unmarried. As might have been expected, recent investigations in the British service in India show that cases of venereal disease are much less numerous among abstainers than among those habituated to the use of alcoholics. In the French army, during the year 1887, it was found that the amount of venereal dis- ease for each garrison depended directly upon the amount of clandestine prostitution; the prevalence of these affec- tions varying directly with the rigor with which surveil- lance of prostitutes is maintained. According to von Tophy, the relative venereal morbidity in the armies of Austria, Germany, France and Italy bears a close rela- tionship to the prevalence of this class of diseases among the civilians in the district in which they are quartered, and hence all measures for the restriction of the disease should primarily be applied to the civil population. The amount of venereal disease also depends, according to Jeannel, upon the virulence of the type of the affection as found in foreign countries, and upon the facility of communication with the civil classes. Measures Looking to the Diminution of Venereal Disease among Troops.—Since no systematic attempt has been offi- cially made for this end, within the limits of the United States, through the control of prostitution in its relations to our military service—save at Memphis and Nashville, during the Civil War, —it is necessary to turn for data on this subject to the ample experience of other nations. In our small army, containing, as it has in the past, a large proportion of married soldiers and scattered in small de- tachments over a vast territory, the necessity for the re- striction of venereal disease among troops through the control of prostitution has not been markedly manifest; and the execution of such restrictive measures would in- deed have been impracticable at home stations. With the altered conditions and changed moral and social environ- ment which have, however, resulted from recent acquisi- tion of foreign territory and contact with alien races, the subject at once assumesa vast importance, believing, as we must, that the experience of the United States as regards the occurrence of venereal disease among troops will not be greatly different in this respect from that of England, France, Holland, and other countries holding tropical col- onies. That we may- profit in the future from their mis- takes of the past, and treat this matter forcefully, practi- cally and with an absence of sentiment, is much to be desired, but, in view of the varying political conditions controlling the policy of arepublican form of government, this is a result which is scarcely to be anticipated. On examining the figures given in the British Army Medical Department Report for 1883, as illustrating the influence of restrictive legislation in England upon the prevalence of venereal disease, the fact which chiefly at- tracts the attention is the enormous difference between the number of admissions for primary syphilis in the districts in which prostitution was regulated as compared with the admissions in the stations not under tie Conta- gious Diseases act. In the former the average annual rate for a period of thirteen years was 50 per thousand; in the latter the admission rate was 118 per thousand. The following table gives the total admissions for pri- mary syphilis and the average strength: AVERAGE STRENGTH AND TOTAL ADMISSIONS FOR PRIMARY SYPHILIS, 1870-82. Fourteen stations under the Fourteen stations not under act. the act. Average strength..... 47,394 Average strength..... 19,218 Total admissions ..... 31,105 Total admissions ..... 29,582 If these figures be compared, it is observed that if in the subjected stations the ratio of admissions had been the same as for those not under the act, the total admissions for primary syphilis would have been 72,952. It is thus obvious that 41,848 men were prevented from contracting the worst form of venereal disease, in this one group of ' stations, owing to the enforcement of the provisions of the Contagious Diseases act. The number constantly in hospital for primary syphilis was only 3.97 per thousand in the group under the act, while in the group in which regulations were not in force it was 9.16 per thousand. The actual number constantly in hospital in the subjected group was 188, but if it were in the same proportion as in the group not under the act, the amount would have been 434; it is therefore evident that there was a daily saving of 246 men from being sick in hospital with pri- mary syphilis. In May, 1883, the act was practically done away with, the compulsory examination of prosti- tutes having then ceased; and the following tables are of interest as showing the disastrous results of interfering with such an essential regulation: CONSTANTLY IN HOSPITAL PER 1,000 STRENGTH, PRIMARY SYPHILIS. Group of stations under the act. Group of stations year ox Period: not under the act. ive i ; 8 "| 12.41 | Act modified 14.01 ADMISSIONS TO HOSPITAL PER 1,000 STRENGTH, PRIMARY SYPHILIS. Group of stations under the act. Group of stations Year or Porn. not under the act. 1870-8 101 188 1883... é 1S ee eee ee 138 s Act modified 160 Browning has compared the admissions for primary syphilis, in the year 1875, at Chatham-Sheerness and Lon- don, one subjected to, and the other not under, the act; the average strength of each being about 4,000 men and. the places not farapart. For the former station’ the admis- sions for this cause were only 17 per thousand for the period! mentioned, while for London the admissions were 187 per thousand. Before the act came into force the admissions. at Chatham-Sheerness were 94 per thousand (average of 1860-66). From 1867 to 1882 the rate was only 49 per thousand. On abolishing the compulsory examination of 611 Camp Diseases. Camp Diseases, prostitutes the ratio for primary syphilis rose, in 1884, to 141 per thousand. The average for London for 1867 to 1882, not under the act, was 181 per thousand. The effect of the Contagious Diseases act in the United Kingdom in the number of admissions for gonor- rhoea was not so marked as in the case of primary syph- ilis; the ratio of admissions for this cause was 84 per thousand in the subjected group, while in the stations not under the act the ratio was 105 per thousand. It is computed, however, that the act prevented about 12,000 cases of gonorrheea during the period 1870-82 at the four- teen stations where the regulations were in force. Previous to 1885, in the British service in India, lock hospitals had been established for the treatment of women suffering from venereal diseases. All prostitutes living in cantonments were registered and subject to medical examination. In many cases special quarters were al- jotted to them in regimental or cantonment bazaars, and women evading the rules were subject to ejectment from cantonments. In that year the Indian Government de- cided that a certain number of these lock hospitals should be closed, with a view to a comparison being made of the results at these stations and at protected stations. In 1887 the results obtained showed that there had been a marked and progressive increase of venereal disease at stations in which the lock hospitals had been closed, and the percentage of disease compared most unfavorably with the percentages at the stations at which these insti- tutions had been maintained. The hospitals previously closed were directed to be re-opened, but in 1888 all control over prostitution in India was done away with by an act of Parliament. Since 1887, the last full year of the protec- tive system, there has been an advance of primary venereal disease of 187 per cent., and of secondary disease of 188 HUNGER Tener ASS ANGEMEOA ConSBerr Hs PO Re 2 EY a a at SRE L A Ul epg a Sp eae olin eA SE Pitim, AMBER ol. Ci pf] toa Pang aol ¢ | | [\I Y | Siae anne PR 4 RS a ed pe pl hall ae S Pik HEDGE AMES Coe Fig. 1094.—Chart Showing the Influence of Laws Regulating Prostitution in the Rohilk- - hand District, India, and Cape Town, South Africa, upon the Admissions, per Thou- sand Strength, for Primary and Secondary Syphilis, from the British Troops Stationed at Black line, Cape Town; dotted line, Rohilkhand. Cape Town, without regulations, 1884-88, average admissions, 371; Rohilkhand, without regulations, 1889-97, average admissions, 370; Rohilkhand, with regulations, 1884-88, average admissions, 132; Cape Town, with regulations, 1889-97, average admissions, 168. those Points. per cent.; a progressive severity of cases expressed by an average stay in hospital of 31.5 days in 1895 as com- pared with 26 in 1887, and a temporary inefficiency of the force exemplified by the fact that in 1895, out of 68,331 men in cantonment 36,681 were in hospital for the above average period, of whom 22,702 were suffering from 612 SUESIRZEREERCOe COREE CCC EEE Ere pape REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. syphilis. The number constantly inefficient from venereal disease was 3,164. The invaliding from this cause ad- vanced from 1.13 per cent. under restrictive measures to 5 per cent. in the statistics for 1895. In regard to the prev- alence of venereal disease in India in 1894-95, the army sanitary commission wrote: “The results of experience in India since 1885, when a number of lock hospitals were closed, and in subsequent years when all restrictive meas- ures were gradually removed, show that a progressive increase of venereal diseases has taken place among the British troops serving in India; and there is, unfortu- nately, no assurance that this increase has reached its limits.” In the year 1889 a Kontarions Diseases act was brought into force at Cape Town, South Africa, and in the same year all regulations for checking the spread of venereal disease were done away with in India; so, for a period of eight years it is possible to compare India, minus reg- ulations, with Cape Town and an act in force. For the five years previous to the act coming into force at Cape Town, the average admissions for primary and secondary syphilis were 371 per thousand of strength. The Rohilk- hand district of India, for the years 1889-96, had just the same proportion of admissions, viz., 8370 per thousand, both stations not being under a Contagious Diseases act. For the nine years (1889-97) during which the act was in force at Cape Town, the admissions gave an average of 178 per thousand; Rohilkhand, for a like number of years (1880-88), having nearly the same number of admis- sions, 184 per thousand, both stations being under a Con- tagious Diseases act. "The accompanying chart graphi- cally shows the influence of the acts upon the admissions for syphilis in these two stations; the heavy vertical lines marking the abolition of all restrictions’ in India, this being followed by an immediate and extraordinary rise; and also showing the point at which unrestricted prosti- tution in Cape Town came under official control, a remarkable and permanent decrease resulting. To such a con- vincing argument of the value of con- trolled prostitution it would be almost superfluous to add. Browning states that previous to the Contagious Diseases act coming into force at Cape Town, venereal diseases of all kinds were rampant, and the ad- missions to the military hospital from this cause appalling, they having reached 828 per thousand of strength. At no other region where British troops were stationed did the admissions reach such proportions. On comparing the admissions to hospital for venereal dis- eases for the quinquennial period be- fore the act, and the years following the act, a vast difference in the total sick with venereal disease was appar- ent. Theaverage forall forms of ven- ereal disease for the years 1884-88 was 674 per thousand, while the average for the years 1889-97 was only 349. This was not a gradual fall which might be accounted for by an improve- ment in morals, but a sudden descent from 828 per thousand in 1888 to 347 per thousand in 1889, and the rate is still decreasing. In 1896 it was only 216 per thousand. In comparing the figures for all forms of venereal disease at Cape Town, it appears that not only has the number of venereal cases fallen since the act came into force, but of late years a large proportion of such affec- tions consisted of milder complaints. These, before the. act, constituted 34 per cent. of the total; for the eight. years subsequent to the act they averaged 49 percent. It is interesting to notice the great fallin the admissions for (SS Od EB 74 Oe (After Browning.) REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. constitutional syphilis. for the period 1889-97. The disease was rapidly increasing when no regu- lations were in force, but twelve months after the act was promulgated the num- ber of attacks fell to what must be con- sidered a satisfactory ratio under the circumstances, and, with the exception of the years 1892, 1894, and 1895, the figures were under 50 per thousand. That the supervision and control of prostitution produce a beneficial effect on the general health of the troops at Cape Town is evident from comparing the total admissions per thousand of strength for all forms of disease, other than venereal disease, before the act, with the admissions after the act. For the five years previous to the act, the In 1888 the ratio for this disease was 209 per thousand, while in 1896 it was only 27 per thousand. The average rate for the quinquennial period 1884-88 was 137 per thousand, falling to 51 per thousand Camp Diseases, Camp Diseases, tracted disease. There was a licensed brothel under su- pervision in the native town of Wady Halfa, and the women there were periodically examined. Very few cases of disease were contracted there. Stringent police | Ly lees} | A [NT VT TTY SAR eo! pe ef jsco| Ve | | ATA TTT P TTT TATA TTT 975 fenagern average annual rate for diseases other than venereal affections was 553 per thousand of strength, while for the years after the act (1889-97) the ad- missions were 502 per thousand, a fall of about 10 per cent. Browning concludes that the Con- tagious Diseases act of the Cape of Good Hope has “been the means of preventing thousands of soldiers in the garrison at Cape Town from being incapacitated by venereal diseases,” and that “the men who still contract such complaints suffer from a milder form than existed prior to the act coming into force.” He believes that “the act is a humane one, relieving the sufferings of hundreds of prostitutes and also alleviating the distress of women who, though not strumpets, contract venereal disease.” In the province of Pinar del Rio, Cuba, during its re- cent occupation by United States troops, the following order was published and enforced: “Clandestine prosti- tution will not be tolerated. Prostitutes shall be regis- tered. They shall live in such locations as are indicated. Each prostitute shall have a book. In this her name, age, nationality, and address shall be recorded. She shall be examined at least once a week by a physician, and the examining physician shall sign the book. This ex- amination shall be good only for one week. Any prosti- tute doing business when her book is not signed to date shall be punished. She shall not change her residence without the permission of the sanitary inspector. The proprietors of houses of prostitution will be held account- able for the condition of the houses and of the inmates, also for the orderly conduct of those living in or visiting such houses. No liquor shall be sold, given away, or drunk in houses of prostitution. Each prostitute will be required to provide the means necessary for securing her own and her visitors’ cleanliness. Cases of venereal dis- ease must be at once reported to the health inspector. When venereal disease is traced to any particular person, such person will be subjected to punishment.” As to the results which followed the enforcement of this order, Kneedler writes: “In connection with the matter of regu- lated prostitution, this command has been in Cuba three months and numbers three thousand men. These men have free access to the towns. I have not been able to find more than nine men who have contracted venereal disease in the Department of Pinar del Rio.” In the report concerning the sickness among the British troops composing the Dongola expeditionary force, in 1896, the chief medical officer says: “On first arriving at Wady Halfa there was some trouble found in checking clandestine prostitution. There were a large number of native women who were living just outside the English lines, and it was from these women that the men con- Prostitution. Fig. 1095.—Admissions for All Venereal Diseases, per Thousand Strength, among the British Troops at Cape Town, Before and After the Regulation and Official «Control of (After Browning.) ad Z. Soar Voile nies pian (Co a WP GPP a 4 ba a ee | re | Ce as Fett fatibrs p | | LS ere Gl 3a am am [aoa Op Ma Rar arias Sfeccecs Ea Rea BIN Steg Yo rE pe tet ly ae Se eer ale BOGE oe sole Lael ES MPa Ho yy Basin precautions were taken, and a military patrol was placed outside the camp to prevent women from coming near, and this answered. so effectively that after a few weeks the nuisance was almost stopped and there were hardly any admissions afterward for venereal.” For the period 1863-65 the Italian army had an admis- sion rate for venereal disease of 120 per thousand; this falling in 1874-76, as the result of sanitary inspection and careful control of prostitution, to 66 per thousand. Such facts as are given above may be greatly multi- plied, and there can be no doubt that the intelligent regulation of prostitution results in a great decrease in venereal disease ; this is to be accomplished by a system in- cluding careful registration and surveillance and frequent official medical inspection. The latter requirement is of the greatest importance, a fact of which the British Sani- tary Commission in India was fully convinced when it reported: “We are satisfied from the evidence that the frequent examination of women is the most efficacious method of controlling the disease.” These examinations should be made in private, and only in the presence of official examiners. The latter may be females who have been sufficiently trained for the intelligent discharge of this duty. Military garrisons attract to their vicinity lewd women of the lowest character, and largely subjects of venereal affections. Such being the case, great care should be taken to prevent loitering or importuning by this class or by their male associates within the limits of the command. Particularly in the tropics it is desirable that no females should be employed in, or in the imme- diate vicinity of, the barracks, since there is evidence that such women are frequently the source of aggravated forms of venereal disease. Clandestine prostitution should be prevented as furnishing a high rate of venereal disease. Colin noted that of,32 syphilitic French soldiers, 14 were infected by public prostitutes and 18 by women employed in so-called wine-shops. AJl public prostitutes should be segregated within well-defined limits as re- gards residence and public solicitation severely punished. Brief printed instructions should be furnished these women as to the dangers and prevalence of venereal dis- 613 Camp Diseases, Camp Diseases, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ease and the importance of cleanliness as a measure of prophylaxis. Next to medical inspection, it is probable that care in maintaining cleanliness of the person is the most important factor in the prevention of venereal dis- ease; it having been experimentally determined that in- fection from the non-syphilitic venereal sore may usually be prevented by a thorough cleansing of the parts with soap and water if done within ten minutes from the time of exposure. When diseased, such women should be at once isolated in a proper institution. Apart from the great importance of such action upon the general wel- fare, it is merely a matter of humanity to these un- fortunates that they should have the benefits of medical treatment, with rest and care in hospital, until they are cured, Obedience to these regulations should be en- forced by police authority, and public exposure, as far as the occurrence of venereal disease is concerned, should, as far as possible, be prevented. It should not be for- gotten that when official control becomes too rigorous the number of avowed public women undergoes diminu- tion, while clandestine prostitution increases. The large amount of venereal disease occurring among troops—a condition entirely preventable and dependent upon vicious indulgences on the part of the soldier—has led many to suggest the institution of measures calcu- lated to prevent its occurrence through the imposition of penalties upon those offending in this respect. It has been suggested that those incapacitated for duty from this cause be deprived of their pay while rendering no service to the government; that their privileges be re- stricted, or that confinement be imposed. All these plans are, however, readily defeated by the concealment of the disease; and the proper imposition of punishment for this cause could be made only with the assistance of a careful system of inspection. In the French service a month’s imprisonment was at one time imposed upon every venereal case after discharge from hospital, but this led the men to conceal their diseased condition from the medical officers and p'ace themselves in the hands of empirics, and the order was revoked. _ It is certainly sub- versive of discipline and unjust to the more continent class of men that they are obliged to perform the extra duty which results from the entrance into hospital, as a result of their own misconduct, of those by whom such work should rightfully have been done. Such a condi- tion of affairs obviously puts a premium upon participa- tion in vice, and it is much to be regretted that no satis- factory method for its punishment has as yet been devised. Where measures for the control of prostitution can be carried out, the soldiers affected with venereal disease should be required to state where and from whom it was contracted, with a view to the proper segregation and treatment of the women indicated. In the British ser- vice, however, during the existence of the cantonment laws, Welch states that some difficulty was experienced, in the attempt to identify the source of venereal infection, through the unwillingness of the soldiers to expose their co-partners in vice. Many soldiers affected with venereal disease hesitate to declare its existence through the official publicity neces- sarily given to all cases, and through reluctance to have their names entered upon the records in connection with diseases of this character. Asaresult of such action the condition is, in many instances, aggravated either by be- ing left without treatment or by the employment of patent medicines or unskilled advisers. Where venereal dis- ease is concealed, the offender, if detected, should be severely punished; and where such practice is general the system of weekly inspection, as is customary in England and on the Continent, may have to be employed. This, in fact, has lately been carried oué among certain of our regiments in the tropics. It should be thoroughly under- stood by the men that it is greatly to their interest, in the way of cure, to declare the existence of such a disease as soon as its appearance is noted. To further assist in the accomplishment of this object, it should be required that all non-commissioned officers knowing of the existence of cases of venereal disease in their troop or company 614 should be held responsible for the prompt appearance of the sick men before a medical officer. It would certainly be of advantage to the military ser- vice if a short series of lectures by medical officers were required to be delivered annually for the purpose of ac- quainting soldiers with the grave and far-reaching con- sequences that are likely to result from immoral conduct, particularly from clandestine prostitution; the impor- tance of early treatment and the dangers of concealment; the intractable character of syphilis and the necessity for prolonged medication; the dangers resulting to the healthy from the presence of concealed venereal disease in barracks. Such lectures would be of special value at recruiting depots. Chastity should be inculcated. The common idea that celibacy increases sickness and mortal- ity should not be encouraged, since although many single men renounce marriage because of bad health or disease, this is a cause not met with in the army, where there is an enforced celibacy analogous to that of priests, who, al- though single, live as long as married men. INSANITY AND SuicrpE.—These are best discussed in this connection, since they are largely dependent upon the personal habits of the soldier, particularly in relation to alcoholism. Mental diseases have undergone a considerable diminu- tion in our service during the past few years, this un- doubtedly resulting from the greater provision officially made for the intellectual needs and recreation of the soldier, together with the withdrawal of troops from small isolated posts and their concentration near large centres of population. The following figures show the rates for this cause for a period of thirty years: Admissions Admissions Admissions Year per 1,000 Year per 1,000 Year. per 1,000 strength. strength. strength. Ask TS7S Fert 15 1888..... Ly 1.5 1879 ence 1.9 L880 ie ace 1.3 2.1 SSUES rte: 2.1 1890.....3 1.3 2.0 Aboot Beira 2.5 ASOT a, oe 1.5 2.4 ISB2 icc as 2.8 1802 1.9 2.2 1883..... 3.0 1893...... 1.3 1.8 1884..... 2.1 SOLS es 9 2.2 IS85 tence 1.4 1885 3ee. a 1.4 1886..... 1.4 1806.5 8 1.6 1SSU hee 1.9 SOGanece 8 In contrast with the conditions prevailing in our ser- vice, as shown above, insanity would seem to be steadily on the increase in the French army. The figures given below refer to troops on: home service and in Algeria, as sanitary statistics are not published regarding the garri- sons at various other colonial stations: Number of men Number of men Year invalided for Year. invalided for mental alienation. mental alienation. thc i Rocmnccncaae 62 f Cote AGGIE CIT 73 BIS: cae celeste 94 \88atee Maen 120 GUO Ri Stecama ert [7 1886 cAiec = sie ae 112 ASSO eetiteeeess 63 L887 sac taser 130 i hotel geen oie 82 1888 costo. 150 TOSCEtertker's 81 TESS S Sarcc eestor 158 ASS Saree cries 64 1800. setae 192 In the British army the rates for mental disease for the ten years 1887-96 are given as follows: Admissions Admissions Station. per 1,000 Station. per 1,000 strength. strength. WN OTANG 1 parels sister olecsters 1.2 Bermuda seamen deents 1.5 Seotland i. Wiemcevecnt 1.8 West Indies.......... ie {relandc, tena cee. ooo 1.6 Geylon s..00% deste 1.3 Gibraltar a iatcecs sear is China.0. 200s aee 1.2 Malta Paice wae coe a hrs Straits Settlements.... 1.5 Camadarg. 2 ccistects pus 38 India 5... occ seg ceca From the above figures it is seen that tropical service, contrary to what might be expected, does not apparently increase the liability to insanity. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. The military spirit, which naturally cultivates indiffer- ence to life, is undoubtedly favorable to self-destruction, and does much to raise the rates for suicide in the mili- tary service above those prevailing in civil life. In ad- dition to this feeling the soldier, constantly under the control of others, separated from home and friends and often occupying isolated and lonely stations, is more prone to melancholia and mental depression and the ten- dency toward suicide occurring therefrom. In the United States service, after the Civil War, the rate for suicide had increased greatly until within the last three years, when there wasa suddenand great diminution. For vari- ous years the rates have been as follows: Suicides Suicides Year. per 1,000 Year per 1,000 strength. strength. BOB rracicenileld vis iar vw se 0.44 ANG} Naoto Goernecie toe 0.83 TVS asp eerene Sereieere 51 TB Od Fore crite sto eater one 79 MSTOrcnnacicsc wees sae:s .63 gts Ounce Aare on SAGE 43 ASaettene tdci s bee see +s 1.10 MOOT S certhe Fs Gotete tia vias 39 In 1898, a year of war, the rate greatly diminished, being only .04 per thousand strength. The suicides for the seven years 1887-93 inclusive amounted to a total of 134 cases: officers 7, and enlisted men 127. These were divided according to the branch of the service as follows: ATE SMISLD Vere tite it wrasels e's. s sissera (eles a o:elele civ wie vie inca ey are eee oamle 64 MPR EAEL.VMatstaVatetetave¥e: clots) ste Par avolcre ative) esa levels) aTele svat ai axe ave dlevote, one rerate 28 PMT NICHE Veet te teres Vet evocd ste)ote' oi slacevateusl svaiacacatatalatsye aise ten entactie oun esate ote 15 RERISU NES Wate te eee ect faye ai esabs arelssie's eieyalecocs wiafe/syare ace, ololevuitieoltaid conip wPoione 5 UIE ERAT SS PEPSI CET ebore atais eiore otece te oars e nis, @ Gina's eid venaiareaiars (stor wine 2 PGA MAU GOSDIGAL. COLDS a raciec sie cctioscocsiovseecceceee re RN MIMCOT IAEA T MURALS ch crs l'ovel'cly eis Hhal'sh nual o date: sialsiptvle’aiaie ial Wis ecalfstaale lo alec 13 Of these, 51 were under 30 years of age, 56 were between 30 and 40, and 27 were over 40. The methods of self- destruction employed were: PRPEML SCO tetera ete plareis a shels. oinle: ata, ditvacato rein wiasaieae’ere:s vslousso aie ole avers ue EMEAOIREN ICC acc ccietas) oes etoncisicleie’ ists elsjoreipcalasaipraip (sia siele’s elses o's 26 EACLE eve MTT tiiolnle ae sols reietels: olsttntnslele sient eva hia, sreressaneia’s @ ye 4 MA ERCSARH CUS DEM Leta leiaeiais, viv siecle! aleve ielounle Gicla oleleis delet ews aisle ide 3 PS ROMIOUTAAL AM ATDON Ye cies ateves's sre neralaielo,e.ers o'yiele" oes eH bole eles ele 1 POEL OMe ECHIN acted aveiayaraiiaioe Wiavodetove's/s wisely Ai el elas anvne oteinaiereuaual e's e-enetoce 1 BaD DteAIa OUT BLOM tense racsievaterstele tere t siveia'e ¢,0,0 slslaiadclaisieate Herre. «revere 1 OMANI DY TAULTOAM TALI ssi01c ccveteie ove seis cielo aie wie eicise vives 1 In 87 instances the causes of the suicide were undeter- mined. In the others the causes were reported to be as follows: PAURCOMAMUISEL aera aniAe oisialsisisie cela cinie\ o/sie\sievgis ie ¢ wyeinvs's aleieiwidl'.0 odie $38.0 42 PA DSEICHAULEAVLES Vener stetawetsieysie a) c7eiseiene sveinis aveutie lieve tisieteiaversie sfelsra.e vin’ ave 12 DIESEL ete tevtera enc aie ase o,oelecerel ec erecelelereie araee'neleieeis oraie a oe asaid sere 10 RI MAIN CLT OM aera pie Sseoe ancliais isiais elvis: ofp lelsiaycierelele-siMervieisle y sacs, ¢.a's 6 DP TMPOLATY. MEMUAL AVETLALION 5, 5,c.cis. x10 /0\s slareyelels sic cise a o:ms wi0(p si 5 MeaIGM COULD MMATUUAL sc sraars cisco costes cloves cies eae Geis se ae © 5 MFT RUC MEROUD LOS ae ialelole eid ciere:eleislaie slot ivta'e ioe eWieveeie oceld Bede 3 Mea Om RESITSION SVPHIUIS is cc. o.c cievaiele are 'sisle v wwlaele seis eb,e\bres 0 2 Meh asics ven ta Ie ARTI LATA IO" ia aVavale (s/s wisvajeraioSetnsels vipiale'e © siesaisasele ve-ecela,ele 2 PP HC INO IMULIOL Geet bat te Wisco) raitiaaicle acres hisnsieTecacesisse et wise eevee 2 PU RSENICI ELST SMEs cre ete the: oik oe ie che. a-oi\iel ofR OMe le & ovate ieteveosdietalara, vw 'elal eaves © 2 POMC SUCHIMESS ty ipleloseiclc pac snician von ofelerelciarerayels @ slolaicineletee'a e o-alete i EEMCRIS LC EOSSIOTIY icteipis «/sie: 016) a,e(ole) e\e.eihleje Vainio. o's aie sushsisies.a oe ove 1 WAL ILE WO, ODUAIM-PrOMObION x a { : ty — G Mir a® - oud om ’ ns , irae 7 7 ne . 4 a a, aes ry os EXPLANATION OF PLATE XX. & Fic. 1.—Cylindrical-cell carcinoma of rectum, showing the invasion of the submucous tissu i muscular coat. X 20. processes of carcinoma cells, The muscular fibres are cut transversely and show vari grees of atrophy. X 150. Fic. 3.—Extension of carcinoma by implantation. ‘Section of a nodule on the surface of the perito- neum secondary to carcinoma of the ovary. The tumor growing on the surface has formed vascular connections with the peritoneum, but has not penetrated the tissue. > 50, WEE ie PF Fic. 4.—Section through a small carcinoma of the breast, showing the rapid peripheral ext and the centralatrophy. The darker areas show the places where the cellsal are most abut xX 10. 3 i ; : ia 4 . 7 a ee a) ‘ f q7 es ee ; ae asa ihe Y .* Vee A a ay : ' a. cH te ale REFERENCE HANDBOOK OF THE MEDICAL SCIENCES Plate XX. PHOTOMICROGRAPHS SHOWING SOME OF THE CHARACTERISTICS OF CARCINOMA. (COUNCILMAN. ) S es é *. =. 3 es ’Y | - ’ v ee 2 u ‘. ‘ is ‘ 26 * : 5 ' eA ‘ . LIBRARY” OF THE ; UNIVERSITY of ILLINOIS. - } ; hae t ¥ “ y ) , REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. yi ahve tog Jarclnoma, stroma and the epithelial masses may be affected by the rapidity of growth of these. When the alveoli are numerous, by their constant enlarge- ment the stroma may be reduced to mere shreds of connective tissue which lie within the cell masses, giving the tumor, or certain foci in it, the appearance of a sarcoma. In the scirrhous type the stroma changes its character, becoming converted into a tissue similar to cicatricial tissue. In this the cells are very few, the fibres are fused together and hyaline. Giant cells are sometimes found in the stroma. Their forma- tion here is analogous to their formation around foreign bodies, and is.a point in favor of con- sidering the stroma a growth excited by the epithelial cells acting as foreign bodies. They are found especially in carcinoma of the skin, in the vicinity of large epithelial pearls which sometimes occupy almost the entire alveolus, and the giant cells often contain the single scales of horny epithelium. Numbers of large epithelioid cells may be found in the vicinity of the giant cells, the group somewhat resem- bling a miliary tubercle. The growth of the carcinoma as a whole is analogous to that of a single alveolus. This can be best studied in sections which are made through small tumors (Plate XX., Fig. 1). The most active growth is found in the periphery. The alveoli here are round or oblong, numerous, and the cells show but little degeneration. In the centre the alveoli are very small and angular, Fig. 1126.—Large Epithelial Pearl from Carcinoma of Tongue. The section the cells are small and degenerated, and there was stained with iron hematoxylin which colors the keratin an intense are butfewnuclear figures. In places the alveoli black. (8 mm. Zeiss.) have disappeared altogether, and there is a dense hyaline cicatricial tissue and a depression is contained in the stroma. In a carcinoma of the skin the | formed corresponding to the atrophic centre. The atro- stroma contains sweat glands, and in the mamma atro- | phy of the centre is partly to be explained by the com- phic glandular tissue. It also contains nerves and blood- | pression and occlusion of the blood-vessels by growing vessels. We may partly explain the new formation of | epithelial masses between which they must pass, and stroma as a formation of tissue to carry new blood-vessels to the masses of epithelium which demand nutrition, just as the inter- stitial tissue is formed in a developing gland. In part, it is due to the presence of the epithelial cell masses acting as for- eign bodies. In some cases it contains large numbers of cells, in others but few are present. The most numerous cells in it are small round cells corresponding to the lymphoid cells of the blood and of the lymph nodes. These are found both as a general infiltration of the tissue and in small circumscribed masses somewhat re- sembling lymph nodules. These cells are usually found in the greatest numbers in the periphery of the tumor, and may even form a compact mass into which the tumor grows. Next to these cells, the plasma cells are most numerous, and are more generally present in carcinomata of the skin. There are also evidences of proliferation of the connective-tissue cells, but these are not present in very great numbers and are con- cealed by the infiltrating cells. In a carci- noma of the uterus, where the cells grow out into a tissue composed of smooth mus- cle fibres, the stroma is formed of muscular tissue. The stroma should not be consid- ered an integral part of the tumor, but it is only an accidental growth due to the mode of development and growth of the tumor. Although the connective - tissue - cells in it are usually not very numerous, they may be so abundant that the stroma resembles the tissue of a sarcoma. Mucoid and other degenerations of the stroma are ¢ Fig. 1127.—Section of Carcinoma of Stomach. The cells have a general cylindrical not uncommon. The relation between the type and are arranged around the walls of the spaces. (8 mm. Zeiss.) Vou. II.—43 673 Carcinoma, Carcinoma, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. partly by the active peripheral growth consuming the nutriment. The centre of the tumor often shows the most typical scirrhous character, while the periphery has the medullary type. The boundary of the tumor is never sharp (Plate XX., Fig. 1); it extends in lines into the surrounding tissues. Fig. 1128.—Atrophic Glandular Tissue from the Stroma of a Carci- noma of the Mamma. (8 mm. Zeiss.) Small masses are found in the vicinity either separated from or connected with the main tumor by a thin line of tissue. There is never any formation of a capsule, and from the nature of the tumor—a mass of epithelium grow- ing into the lymph spaces and lymphatics—it is impossible that there should bea capsule formation. cell masses are often surrounded by infiltrating cells, but they may be found in tissue perfectly normal. Growing as it does, the tumor enters into a tissue, and the essential constituents of the tissue give way beforeit. The destruc- tion and invasion of tissue in contact with it is one of the most marked characteristics of the carcinoma. The de- struction of the tissue doesnot seem to be brought about by the pressure exerted by the growing cells, nor do the invading cells remove it by phagocytosis. This process can best be studied in the skin and inmuscle. When the tumor extends toward the skin this usually becomes thin and atrophic before coming into actual contact with the cell masses. The cell layers diminish in thickness until there may be but a series of two or three cells below the horny layer. No nuclear figures are seen in the cells. Occasionally in a few places single carcinoma cells and even single groups of them may be found within the cells of the epidermis. The skin over the tumor is not ele- vated, but more generally depressed. The atrophy of the skin is due to the demands for nutrition made by the advancing tumor. No new cells are formed, and the old cells gradually become horny and are cast off. Where the tumor enters into the dense connective tissue of the skin there is usually a peculiar relation of cells and stroma. Thesmall lymph spaces of the skin here cannot dilate under the pressure of the cells infiltrating it, so that there is an interlacing system of small alveoli filled with epithelial cells lying in a dense unchanged stroma. There is usually no appearance suggestive of new forma- tion of stroma. In contact with the muscle, as where a carcinoma of the breast comes in contact with the pecto- ralis major, the tumor extends first along the connective- tissue septa and coarsely infiltrates the muscle. In places the growth is more rapid and small nodules may be formed in addition to the general infiltration. At this stage the muscular fibres are small and atrophic. Later there is extension between the fibres themselves, The 674 The advancing. fibres lose their striation and are converted into hyalin.. In places the degenerative increase in the nuclei is prom- inent. Phagocytic giant cells may be formed in the stroma. and these take part in the absorption of the necrotic fibres. . The epithelial cells may push their way into the sarcolemma and extend within this. A section through. such a place shows a general infiltration of epithelial cells arranged with some regularity in long lines parallel! to the muscular fibres, and among them, small, generally angular remains of the fibres may be seen. The epithelial cells infiltrate the loose tissue, and there is no sharp dis- tinction between cells and stroma. The same process of’ atrophy and gradual disappearance of tissue is seen in. the extension of the tumor into such a parenchymatous organ as the liver. There is more evidence of the effect of pressure here than elsewhere. The liver cells in the vicinity are usually flattened or have a cylindrical form. In some cases, especially where the extension is very rapid, there is but little evidence of pressure even here. When the tumor comes in contact with the fat it extends. in the larger connective-tissue septa, then along the fine septa between the fat cells. These become reduced to- small spaces which finally disappear, the cells of the tumor filling the entire tissue. There is but little stroma. in the tissue, Nothing shows better how little part the: stroma playsin the tumor than the study of the periphery of a rapidly growing tumor. The abundance of the- stroma has a direct relation to the amount of connective: tissue in the tissue invaded. Different tumors vary enor- mously in the degree of their infiltration. One occasion- ally sees tumors in which the growth is almost as homo- geneous as is that of a benign tumor, in which it is almost. possible to determine the limit of the growth by the naked eye. As the direct opposite to these are tumors with: such extensive infiltration that small extensions may be found far beyond what appears to be the periphery. Not only is there this general growth by infiltration. but small nodules of the tumor are found in the surround- ing tissue, this being termed dissemination. These small nodules may be connected with the main mass by small: lines not visible to the unaided eye, or they may be inde- pendent. They are found in carcinoma of the breast,. Fig. 1129.—Pectoral Muscle Invaded by Carcinoma of the Breast. with great Numbers of Lymphoid Cells in the Stroma. The larger dark areas represent the atrophied muscular fibres cut obliquely. (8 mm. Zeiss.) ' more generally beneath the skin than in the deeper tissue. They repeat all the characteristics of the main tumor. Their presence is easily explained by a careful examina- tion of the tissue in the vicinity of the tumor. This often. - REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. shows dilated lymph vessels filled with small masses of epithelial cells, or, in some cases, with single cells. I have sometimes been able to see the beginning of a per- ipheral nodule in an extension of the epithelial growth Fig. 1130.—Cross Section of Muscular Fibres Invaded by Carcinoma. The fibres are small and irregular in shape. (8 mm. Zeiss.) from such a vessel into the surrounding tissue. The cells are carried passively in the lymph stream. Exam- ination of the fresh tissue of a carcinoma ona warm stage shows that the cells have slight amceboid movement, limited to the extension and retraction of processes. There is no evidence of such an extent of amceboid movement as would lead to a voluntary progression of the cells into the tissue, nor is it necessary to assume such to explain these secondary nodules. It is characteristic of the tumor not only to grow by infiltration and dissemination, but small tumors similar to the original are formed in distant parts. These are termed metastases. They are due to the convey- ance of tumor cells, by means of lymphatic and blood-vessels, from the primary tumor and their deposit in the places where the metastases appear. The relation between the epithelial masses and the lymphatics is so close in the carcinoma that the metastases appear first in those lymph nodes into which the lymphatics of the tissue in which the primary tumor is seated enter. Thus in car- cinoma of the breast the first metastases are in the axillary lymph nodes, in carcinoma of the uterus, in the post-mesenteric lymph nodes, etc. We have already spoken of the fact that single tumor cells and small connected masses of them may be found in lymph vessels in the vicinity of the primary tumor. The affected lymph nodes are enlarged and may contain small, grayish masses or be entirely converted into tumor. They may be affected and yet show to the naked eye no evidence of this. So general is this second-. ary affection of the lymph nodes that surgeons in all cases of operation for carcinoma of the breast remove the axil- lary nodes. Microscopic examination of the nodes, partic- ularly those which to the naked eye show no lesion, often give clear indications of the manner in which the infec- Carcinoma, Carcinoma, tion has taken place. The metastasis begins in the per- iphery of the node at the place of entrance of the afferent lymphatics. These are often dilated and contain masses of tumor cells. There may be one or a number of small tumor foci in the periphery of the node in immediate re- lation with the lymphatic sinuses, or these may be gen- erally injected with tumor cells. The peripheral sinus of the node is not infrequently seen filled with growing masses of the tumor which from here extend into the lymph nodules. Between the masses of epithelial cells there is in the beginning only the lymphoid tissue of the node. After this atrophies, its place is taken by connec- tive tissue. The character of the original tumor is re- peated in the metastases, although in general the cells of the metastatic growth show less of a physiological ten- dency than do those of the original tumor. In the metas- tases of carcinoma of the skin the tendency to pearl for- mation is less marked, and in those from glandular carcinomata the cells do not usually show the tendencies to physiological arrangement which may be marked in the primary tumor. The extension of a primary carci- noma into adjoining tissue may involve other sets of lymph vessels. When a carcinoma of the breast extends deeply into the tissue beneath, metastases may develop in the lymph nodes of the anterior mediastinum. Only the lymph nodes which are primarily connected with the original tumor may be affected, or the process may ex- tend from these into adjacent nodes. The tumor growth may affect the entire node, and the cells find their way into the efferent lymphatics, or they may pass through the node by means of the lymph stream without produc- ing a growth. In extensive metastatic formation in the axillary nodes the clavicular nodes also are usually in- volved. The detection, by microscopic examination, of metastases in the lymph nodes is usually easy, though in some cases the lymph sinuses are filled with large endothelial cells which have some resemblance to carci- noma cells and may be mistaken for these. Metastasis by means of the blood circulation is less common in general than that which takes place by way of the lymphatics, although in carcinoma of the intesti- nal canal the former mode of disseminating the disease FG. 11381.—Superficial Lymphatics of Skin Dilated and Filled with Masses of Carcinoma Cells. From a carcinoma of the scrotum with numerous metastases. (No. 3 Leitz.) is the rule. The tumor cells may enter into the blood by means of the lymph circulation, or there may be a direct growth of the primary tumor into the blood-ves- sels. In carcinoma of the liver a growth of the tumor into the portal and hepatic veins is so common that it 675 Carcinoma, Carcinoma, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. may almost be regarded as the rule. The frequency of metastases by blood-vessels in carcinoma of the intestinal canal is probably to be explained by the presence, in the latter situation, of numerous and thin-walled veins, which offer less resistance to the extension of the tumor into them. Where the metastases take place depends upon the distribution of the blood-vessels coming from the part. The metastases transported, by way of the blood channels, from the primary tumors of the intestinal canal, are found in the liver, while those coming from tumors in other parts of the body are found in the lungs. There are certain exceptions to this because the tumor emboli may pass like other emboli in the direction op- posite to that of the blood current. Thus metastases may be found in the liver secondary to carcinoma of the lung, or in the kidney secondary to carcinoma of the liver. In these cases the emboli are probably larger and are carried by the force of gravity in the reverse direction to that of the blood stream. Very interesting combinations are often found of metastases by both blood and lymph circulation. Thus I have seen in car- cinoma of the uterus metastases in the post-mesenteric lymph nodes, and from these a growth of the tumor into the thoracic duct, converting this into a large carcino- matous cord which extended into the subclavian vein. There were numerous very minute metastases in the lung simulating miliary tubercles, and from these extension had taken place into the subpleural lymphatics, which were actually injected with the tumor masses, and into the bronchial nodes. The metastases by way of the blood-vessels may be single or so numerous as to simu- late a case of acute miliary tuberculosis. In such cases the condition is spoken of as a general carcinomatosis. Extension of the tumor may also take place at various places on the surface, due to the implantation of masses of a tumor along an adjoining surface (Plate XX., Fig. 4). We find examples of this in the appearance of nu- merous nodules on the surface of the peritoneum in car- cinoma of the ovary which extends to the peritoneum. Such metastases are most apt to be found in those situa- Fic. 1132.—Section of Ovarian Tube in a Case of Carcinoma of the Ovary. There are numerous tumor masses both in the wall and in the lumen. The involvement of the tube was most marked at the distal end. The process probably began in the lumen and from this extended into the wall. (80 mm. Leitz.) tions where solid particles are carried by the force of gravity. There may also be extension by implantation along the surfaces covered by epithelium. In carcinoma .of the kidney tumors may be found along the course of the ureters or in the bladder. In carcinoma of the ovary they may be found in the Fallopian tubes. The carci- noma often shows a marked tendency to extension along 676 the course of the nerves by means of the perineural lymphatics. The nerve as a whole may be surrounded and compressed by masses of epithelial cells or these may be found between the single nerve fibres. In carci- noma of the tongue involvement of the inferior maxillary branch of the fifth nerve is common. The extreme pain which so often accompanies carcinoma can be explained either by extension of the tumor into the nerves or by their compression in the contracting stroma. ‘Tumor cells are rarely found free in the blood-vessels as they are in the lymphatics, but are usually associated with thrombi, and the main mass included in the thrombus may be degenerated. I have frequently found a ves- sel entirely occluded by a mass which was composed of fibrin and necrotic tumor cells, and along the wall of the vessel, where they could obtain nutrition from with- out, there could be seen a line of growing cells. In one case of carcinoma of the breast I found a small, round mass of epithelial cells, the centre of which was degen- erated and filled with leucocytes, around this a small layer of fibrin, and on the outside evidently circulating blood. Such a mass was probably broken off from a fresh tumor thrombus and may have been actually in process or transportation. It is important to determine, in carcinoma, whether the tumor originates in single cells or groups of cells which continue to grow, or whether it starts from a compara- tively large area of tissue, or, finally, whether tissues of a similar character coming in contact with the growth can develop the same tendencies. It is very difficult to determine these points by microscopic examination. In carcinoma of the skin we undoubtedly often find large areas of epidermis in direct association with the tumor. It is also possible to find the epidermis in the vicinity of the tumor, but not immediately connected with it, apparently taking part in its growth, and growing in the same manner. The same thing is true in carcinoma of other epithelial surfaces, as in the alimentary canal. Here we often find the tumor in continuity with the glands over a large extent of the surface, the glands ap- parently growing into the tissue be- neath and branching in this. Ribbert, who holds that the origin of the car- cinoma is due to the separation of single epithelial cells and their inclu- sion in the connective tissue, believes that this connection of the tumor with the epithelial tissues is really second- ary, and due to the extension of the tu- mor to the surface with the formation of a connection between the cells of the tumor and the epithelial surface. It is certainly true that when metastasis takes place the parenchymatous cells of the organ invaded take no part in the growth. Thus, in the secondary nodules in the liver, the liver cells are never converted into those of the tu- mor. When a glandular carcinoma comes in contact with epidermis, al- though this may actually be invaded by the single cells of the tumor and be in contact with tumor epithelium, there is no transformation. In.a carcinoma of the breast the glandular tissue is usually atrophic. The tumor tends to extend along the ducts which may be surrounded by lymphatics filled with . tumor cells, and yet the epithelium of the duct may show no change. In other cases the epithelium certainly ap- pears to take part in the growth. There may be a sim- ple proliferation of epithelium leading to the formation of projecting papillary masses within the duct, or in combination with this there may be an outward growth of the epithelium into the surrounding tissue. The cells change their character, becoming larger and taking on all the characteristics of the tumor cells. Undoubtedly, - REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Carcinoma, Carcinoma, for most of these conditions the explanation of secondary tumor extension given by Ribbert applies. In favorable sections, and especially in series of sections, the tumor evidently extends from the outside into the duct, and the tumor epithelium grows over or replaces the epithelium of the duct. It is often possible to distinguish definitely between the epithelium of the duct and the ttmor cells in connection with it. In other cases this explanation will not suffice. The clearest evidence of a participation of the general epithelial structures of a part in the growth of the tumor was given in a case of carcinoma of the skin, ih which there were undoubtedly prolifera- tion and outward growth of the epithelium of several hair follicles which were in the immediate vicinity of the tumor, but in no way connected with it. I have seen a similar condition in the ducts and alveoli in car- cinoma of the breast. I have already spoken of the necrosis in the centres of the cell masses (Fig. 1125). In addition to this there may be more exten- sive necrosis involving either entire alveoli or masses of alveoli with stro- ma. Such necrosis is due to disturbances of circula- tion, usually by compres- sion of arteries or veins, or both, by the growing tu- mor masses between which they run. In other cases it is due to the formation of thrombi. The necrotic tissue may remain, undergoing but little change, or it may be absorbed and its place taken by dense cicatricial stroma. The boundaries of the necrotic tissue are often extremely irregular, unchanged tumor tis- sue projecting irregularly into it. Hemorrhage may ac- company the necrosis, but is not common. Where the ne- crotic tissue comes in contact with the surface bacteria may enter, producing gangrenous softening accompanied by suppuration. Ulceration is a common accompaniment of both the glandular and the surface varieties of carcinoma. When the tumor extends to the surface the epithelium over this gradually disappears by atrophy, and the tumor appears as a raw uncovered mass resembling somewhat the base of an ordinary ulcer, although it is smoother and paler. There is always on the surface a thin line of ne- crosis due to the action of traumatic causes. In addition to this there is more extensive necrosis extending irregu- larly from the surface into the tumor tissue. The cells of the tumor at the surface are placed under more unfa- vorable conditions as regards their nutrition than are the cells in any other part of the tumor, for they receive their blood-supply from one side only, and constriction of the vessels is constantly going on. Necrosis due to this takes piace and assists in the extension of the superficial trau- matic necrosis. The necrosis is always assisted by the action of bacteria, and extensive gangrenous sloughs may be produced. There is continuous new formation of tis- sue pushing up from below, so that the ulceration is usu- ally not deep and gives but little idea of the extent of the loss of substance. The destruction of tissue may be so extensive that in spite of rapid growth the resulting tumor may be insignificant in size. In carcinomata of the lip the surface of the tumor may appear as an ulcer somewhat depressed, or be covered by a scab formed principally of a mass of cast-off epithelial scales. When a glandular carcinoma extends to the surface it is not usually covered by a scab, because but little exudation can find its way from the tissue beneath to take part in its formation. Fic. 1133.—Longitudinal Section of a Large Duct in Carcinoma of the Breast. of the duct is partly preserved but in places it is covered by a growth of the carcinoma cells which extend into the lumen from the walls. Ulceration plays a very important part in carcinomata of the intestinal canal, especially in those of the stomach, and the results of the process differ somewhat from the results of the process elsewhere. The necrotic tissue is destroyed by the action of the gastric juice, leading to the formation of a smooth, clean ulcer, and the tumor grows in elevated masses around the edge of this. The process of necrosis may be so active that the ulcer may resemble a simple ulcer and only by microscopical ex- UP ae Se SERS os CA 2 The cylindrical epithelium (No. 8 Leitz.) amination of the edge can its character be determined. in other parts of the intestinal canal necrosis with result- ing gangrene is more common, though we may have in the rectum carcinoma with ulceration, of the same char- acter as that in the stomach. In the alimentary canal the contraction which so constantly accompanies the growth and which is due to the conversion of the stroma into cicatricial tissue, leads to constriction and occlusion of the lumen. The occlusion is assisted by the action of the elevated tumor masses around the ulcer. Constitutional E7ffects.—The effect of a carcinoma on the individual remains to be considered. The most constant condition accompanying it consists in emaciation and the production of cachexia. The cachexia is probably due to a number of conditions. The malnutrition is due in the first place to the loss of sleep induced by pain. The absorption of the toxic products coming from the necro- tic tissue may interfere with the nutrition and produce a condition of chronic toxemia. To this must be added the absorption of toxic substances from bacterial action, and finally a general infection produced by bacteria which have invaded the tumor. The evidence of such condi- tions is seen not only in general degeneration of the organs but in such special degenerations as amyloid. Changes in the blood are unimportant. In the later stages there may be considerable diminution in the number of red cor- puscles. The leucocytes may remain normal or show some increase, this particularly when ulceration is present. Htiology.—The cause of carcinoma remains in absolute obscurity. A fair measure of our absolute ignorance of the subject may be found in the number of theories which have been advanced, each of which has its advocates and each of which is favored by certain conditions associated with the tumor. The first of these theories and the one which probably still has the most adherents is the traumatic the- ory which supposes the tumor to be due to the continuous action of an irritant which excites the cells to prolifera- tion. Virchow has been the most prominent defender of this theory and many surgeons have supported it. Car- cinoma of the lower lip, which is practically confined to 677 Carcinoma, Carcinoma, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. males, is used in support of the traumatic theory, being supposed to be due to smoking. The development of carcinoma in the site of old cicatrices, particularly those resulting from burns, is also used in favor of the trau- matic origin. Probably the facts of the infrequency of carcinoma in those parts of the body most exposed to trauma and its frequency in those parts least exposed are the strongest arguments against the traumatic theory. No parts of the body are so exposed to traumata of various sorts as the hands and feet, and yet the tumor is exceed- ingly rare in the former and almost never occurs in the latter. No parts of the body are less exposed to trauma than the mammary gland and the uterus, and the tumor is very frequent in these situations. Even in the pessary days of gynecology, when the uterus was possibly the most abused organ in the body, carcinoma of this was not rendered more frequent. In the example given of the association of carcinoma of the lower lip and smok- ing, the infrequency of the tumor in the upper lip, in spite of the fact that this must be as much exposed to the traumatic or irritative ac- tion of the tobac- co, is not explain- ed. Carcinoma is not more frequent in those who by reason of occupa- tion or conditions of life are more subject to trau- mata. Another example often cited to show the influence of trau- ma is the associa- tion between gall stones and carci- noma of the gall bladder. This tu- mor is about four times as common in women as in men, and lacing in association with gall stones is sup- posed to be a fa- voring cause. It is undoubtedly true that gall stones are constantly found associated with the tumor, but this may be due to the fact that their formation is favored by the production of necrotic tissue which may serve as a nidus in the formation of the concretion. It has also been urged that in cases of metastatic tumor formation in the gall-bladder calculi are not found, but here again the in- frequency of ulceration and other conditions which would favor their formation must be considered. It would not do to dismiss the influence of trauma in the production of the tumor as altogether incredible, but if it plays any part it must be a very minor one, or it may help in the action of other causes. There is much that may be said in favor of the germinal theory of origin. This assumes that in the course of em- bryonic development remains of embryonic tissues may be included within the normal tissues, and from such embryonic remains, or from certain cells which have re- tained their embryonic capacity for growth, the tumor may develop. In favor of this theory it may be said that such remains of embryonic tissues do become included within normal tissues and from them tumors often de- velop. This theory, though not original with Cohnheim, was taken up by him and advocated with all the force and charm which characterize his work. Ribbert has of late advanced a theory of formation which may be said to be a modification of the germinal theory. He supposes that not only such embryonic re- mains of tissue may be included in other tissues, but in 678 Fig. 11384.—Bile Duct of the Rabbit from a Case of Psorospermosis of the Liver. is dilated and partly filled with a papillary growth. lumen. The younger forms are in the epithelial cells. the course of pathological processes epithelial cells may be separated from their connection with one another and enclosed in the connective tissue. The stroma, for him, forms an integral part of the growth, and the tumor usu- ally begins with cellular infiltration of the connective tissue. There is much that is opposed to this theory of Ribbert’s. The cellular infiltration around the edge of a young carcinoma, though commonly present, may be entirely absent. I have regarded it as due to the reac- tion of the connective tissue to the presence of epithelial cells out of place and which act as foreign bodies. It is not at all an uncommon thing in the course of surgical operations to have both collections of epithelial cells and single cells included in the connective tissue, as in the suturing of wounds of the skin or intestine, and the same thing probably takes place in any operation on a glandular organ. The cells may remain in the tissues for a considerable time and may even show evidences of growth, but they are finally destroyed by the phagocytic action of cells de- rived from the tis- sue. Another point against the theory of Ribbert is his assumption that the small-cell infiltration is in- dicative of activ- ity on the part of the connective tis- sue and the cells are derived from this. They are really chiefly lymphoid and plasma cells, and the condition may not betoken any activity whatever on the part of the connective tissue. Boll, in 1876, spoke of the im- portance of the stroma in the car- cinoma. He says also that in the de- velopment of the tumor there is marked proliferation of the connective tissue, leading to the formation of a vascular germinal tissue into which the epithelial growth takes place. He thinks that the formation of such a tissue is the one essential condition for the formation of carcinoma, When it is formed the old strife between the epithelium and the connective tissue breaks out anew. ‘Thiersch, also, says that the fre- quency of carcinoma in old people may be due to de- generative conditions of the connective tissue which can no longer successfully oppose the growth of the epithe- lium. In this connection it must further be remembered that the epithelial cells of a carcinoma do not grow as does ordinary epithelium. The cells may retain something of their physiological tendencies as shown in their manner of growth, but they have a capacity for growth and an activity of growth far in excess of any normal tissue. Hansemann has called particular attention to the very marked difference in structure and in the manner of multiplication in the cells of the carcinoma as contrasted with normal epithelium. The enormous capacity for growth is not due to the abnormal situation in which the cells find themselves, but to certain qualities in the cells themselves. In their abnormal situation they are not placed in the most favorable conditions for nutrition, but in spite of this their growth is so rapid that the increase more than compensates for the cell destruction that takes place. Normal epithelium placed in the same situation shows only a limited power of proliferation and finally disappears. The duct The empty capsules are seen in the (8 mm. Zeiss.) ————— Shc m REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. This being the case, nothing was more natural than to ‘suppose that some influence was exerted on the cells giving them other properties, and with this came the idea of the parasitic origin of carcinoma. In the first place, there seems much analogy between a carcinoma and such an infectious disease as tuberculosis. Both arise in some primary point, and from there the same process extends farther by means of the blood and lymphatic vessels. But the analogy does not go further. In tuberculosis the nodules are due to proliferation of the ordinary cells of the tissue and to exudation. The tissue formed has certain characteristics due to its arrangement and ten- ‘dency to necrosis, but the same elements which compose it may be found ina variety of conditions. In carcinoma the new formation of tissue has a definite structure and could not arise from simple proliferation of the tissue elements. In infection of certain epithelial surfaces by protozoa there may be marked epithelial proliferation which may ‘somewhat simulate a tumor, but the growth is typical and if the infection proceeds further the character of the formation in which it appears is modified by the character of the tissue. Examples of this are seen in the psorosperm infection of the alimentary canal and liver of the rabbit. In the infectious disease the pathogenic organism alone is necessary; in the carcinoma the cell is the infectious agent. The infectious disease may be transmitted from one individual to another. There is no evidence to show that carcinoma is ever transmitted from one individual to another under natural conditions, and even inoculation experiments which have been made from man to man and from man to animals have always been without any result. There have been cases, however, of successful inoculation from place to place on the same individual. In animals it has been possible to transfer carcinoma from one animal to another by implanting pieces of the tumor. Even if the carcinoma could be inoculated from man to man, or even from man to ani- mal, it would be nothing in favor of its parasitic origin. Wher the disease once develops, when the epithelial cells once take on the peculiarities of growth which character- ize the tumor, these cells are practically parasites. They live in strange situations and at the expense of the tissue which is their host, and have the power of unlimited in- crease. It might even be possible to suppose that favor- able conditions for their increase might be provided out- side of the body, and the disease might be transmitted by inoculation with generations of cells which have de- veloped in vitro. It seems most remarkable that it is not possible to place these cells, still growing and contained in tissue, in another individual and have them retain their power. It is possible that there may be certain ‘chemical differences in the tissue fluids of an individual with carcinoma which are favorable or essential for such a growth of the cells. The carcinoma is easy of explanation after it has begun; the difficulty is in finding its primary cause. Ground for the assumption of a parasitic origin has been found in the supposed increase in the frequency of carcinoma. If it is due to embryonic causes or trauma or any such constantly acting cause, there should be no likelihood of increase. If due to parasites, carcinoma, like other in- fectious diseases, should show periods of increase and de- cline. There seems to be little doubt, from the numerous statistics which have been gathered on this subject, that there has been a marked increase in the mortality from carcinoma in the past twenty-five years. There are a number of things to be considered in connection with this increase. There has been an increase in longevity, due principally to diminished mortality in the infectious diseases. Carcinoma is essentially a disease of later life, and more people reach what may be termed the carci- noma age. The diagnosis of carcinoma, especially of the internal organs, has become more accurate and deaths are now properly attributed to this disease which were for- merly put down under other heads. Deaths from carci- noma were formerly concealed as much as possible, due to a horror of the disease and fear of a supposed heredi- tary family taint being known. Hospital surgeons have Carcinoma, Carcinoma, a general idea that the disease is increasing, from the in- creased number of cases which come to the hospitals for operation, due to the much greater success which now at- tends such operations. There still remains a great deal of work to be done on the statistical side, with a careful consideration of the operation of other causes, before we can say*how much the disease is increasing or if it is in- creasing at all. The increase as generally shown is not in favor of the parasitic theory, for it has been gradually progressive, and not marked by exacerbations and remis- sions as would be the case with an infectious disease. Although from a theoretical point of view all that we know about the carcinoma would oppose the parasitic theory, the proof of this is believed by some to have been shown by the actual presence of parasites in the cells themselves. No consideration need be given to the old works on this subject, in which bacteria were found in cultures made from tumors. No connection was ever shown between the tumor and the bacteria and no results followed from inoculation. Following this there have been numerous descriptions of other organisms than bac- teria, and attempts have been made to cultivate these sup- posed organisms and to reproduce the disease by inocu- lation. At first these problematical organisms were supposed to be protozoa, and in some cases the entire life history of the organisms was described. Since the work of Busse the protozoic idea has been given up and most of the present writers on the subject describe the organ- isms as belonging to the blastomycetes. All of these descriptions depend upon certain bodies which are in- cluded in the cell protoplasm. These bodies included in the protoplasm differ in their size, form, and staining reactions. There are certain among them which have about the same size and apparently the same structure, and these have been especially selected as being varieties of the yeasts. They are not universally present in all carcinomata. They are found more frequently in carci- nomata of the breast than in those developing from any other part, and have seemed to me to be more frequent in those tumors and portions of tumors in which degenera- tions are more frequent. They are not present in carci- nomata of the skin. These bodies are in the vicinity of the nucleus and as arule they have about the diameter of a red blood corpuscle, though they may be much smaller or larger. In some cases they are as large as the nucleus of the cell. They usually have a sharp edge separating them from the protoplasm and occasion- ally a small space may be seen at one side, but they do not lie in definite vacuoles. They have a homogeneous, non-granular structure, and usually there is a single granule in the centre of about the size of the nucleolus of a cell and which stains in the same manner. Not in- frequently there are radiating lines which extend from the central granule to the periphery of the body. ‘ Plimmer, an English investigator, has laid great stress on these bodies and regards them as the specific organ- ism which produces the tumor. The number of these bodies varies enormously. In some tumors almost every alveolus contains several of them, in others they are wholly absent. They have no specific staining reactions. Plimmer has devised a special stain to demonstrate them, but they may be shown by the ordinary stain of hama- toxylin and eosin. They are certainly the most distinc- tive of all bodies included in the protoplasm, but there is nothing in their size, form, structure, or staining reac- tions w vhich should lead us to consider them living para- sites. The other objects included in the protoplasm may be divided into two classes. One class is composed of bodies generally round, sometimes single, sometimes in groups, always homogeneous and closely invested by the protoplasm. They stain in various ways, and many of them have a special aflinity for certain dyes and in this way may be sharply differentiated from the proto- plasm. Russel described certain of these which are sharply stained with fuchsin, and which have since been generally known as Russel fuchsin bodies, and he regarded them as probable parasites. Bodies similar to these may be found in a large number of pathological conditions, 679 Carcinoma, (Skin, Carcinoma of the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. and they are obviously nothing but various forms of de- generation of the protoplasm. The third group of bodies are the most variable of all. They always lie in vacuoles in the protoplasm. They are irregular in size, and care- ful study will show every variation between the most in- definite of these bodies and structures which may cer- tainly be recognized as cells, and even the special variety of cells may be distinguished. The cells of carcinoma differ further from ordinary epithelial cells in their marked phagocytic properties. The included cells may be cells or portions of cells from the tumor itself, poly- nuclear leucocytes, or the lymphoid and plasma cells of the stroma. The last two groups of inclusions are easily explained; they are in no way peculiar to carcinomata or any of the tumors. The various transformations which included cells may undergo can probably be better studied in the large cells of typhoid fever than elsewhere. They are also very numerous in the proliferating connective-tissue cells of granulation tissue. The bodies first described are more difficult of explanation and probably no single explana- tion of their origin can be given. Iam convinced that many of them are due to degeneration of the nucleus. Ina tumor which developed ina cicatrix after the opera- tion, and in which they were very numerous, it was possible to see transitions in the nuclei leading to these bodies. The chromatin of the nucleus disap- peared, the whole structure becoming homogeneous, and the nucleolus remaining as the central granule. They may also be referred to degeneration of segments of the nucleus which are occasionally thrown off and which represent the degenerative direct division. Borel be- lieves that some of them are certainly to be referred to changes taking place around the centrosome, the radiate bodies being the spindle, and the granule in the middle the remains of the centrosome. In the giant cells of a sarcoma I have seen degenerations of the numerous cen- trosomes which become swollen up and the spindle around them more definite, but none of these bodies were found. Whatever the explanation given, there is nothing in the present state of our knowledge which should lead us to regard them as parasites. The de- fenders of the parasitic theory have been able, in a small number of cases, to cultivate yeasts from carcinomata. They have inoculated animals with these cultures and in a very few instances, not more often than could be ex- plained as a coincidence, epithelial tumors have resulted. Almost invariably the new formation of tissue which has resulted from the inoculation has been granulation tissue of a sort which would follow from the introduction of any injurious agent. It would not be justifiable to deny the possibility that carcinoma may be due to a parasite, but no evidence of this has been adduced up to the present time. On the contrary, everything we know of the tumor speaks against this idea. Ifa parasite is the cause, it must be different from any form of parasite we know, and its relations to the tissue must be different. It would be difficult to assume that a parasite could infect the tissues at a certain point, giving to the cells certain properties which would be retained “by all following generations of cells. Otherwise we must assume a symbiosis be- tween cell and parasite, as the parasite must be present in all cells and be carried with the cell to produce a metastasis, for a metastasis cannot be due to a parasite alone. When the carcinoma once starts the cells themselves act as parasites. In the removal of a carcinoma, if the operation is to be successful, all the parasitic cells must be removed. It is not sufficient to remove the primary tumor and the lymph glands connected with the tissue, but the tissue between the two, in which the lymph vessels run and which may contain straggling cells, must also be removed. It may be extremely difficult to do this, for the blocking of the glands by metastases and the occlusion of the ordinary lymph channels may bring other collateral channels into play. The frequency with which the tumor reappears in the cicatrix after opera- 680 tion may possibly often be due to infection of the in- cised part by the knife of the surgeon. W. T. Councilman. CARCINOMA. (CLINICAL.) See Cancer. (Clinical.) CARCINOMA OF THE SKIN.—A uniform nomencla- ture of malignant growths of epithelial tissue is, even in the present state of our pathological knowledge, by no means employed by writers. In a general way, however, carcinoma is used to desig- nate all varieties of malignant growths of epithelium, in- cluding both the glandular and the surface varieties. The majority of writers use the term epithelioma when referring to primary cutaneous cancers. Fabre and Domergue* make a clinical and pathological distinction between epitheliomata and carcinomata of the surface in the manner of growth (orientation) of the cells and the relationship of the cells to the basal layer of the epidermis. In the present article carcinoma is employed as a com- prehensive term embracing all the varieties which have their starting-point in the surface epidermis or its ap- pendages. SyMPTOMATOLOGY.—The primary forms which skin cancers assume depend to some extent on their seat and minute structure. We are unable, because of so many exceptions to this statement, to formulate any rule which will always associate a definite clinical type with a fixed histological structure. The old division of carcinomata of the skin into (1) the superficial, flat, or discoid, (2) the deep-seated, nodular, or infiltrating, and (3) the papillary, is still largely em- ployed as furnishing convenient terms for use in descrip- tions. This classification is more or less imperfect, as the flat or discoid form may become deep-seated, the latter in- volving the skin secondarily asa superficial growth, while both are at times complicated by papillary outgrowths, Unna+ has attempted to reduce the majority of skin carcinomata to a few types according to the gross histo- logical appearances or architecture of the growths. He obtains in this way three chief forms which he designates (1) the fungating, (2) the cylindrical, (8) the alveolar, each of which is further subdivided. A fourth or sub-form (carcinomatous lymphatic infarction secondarily affecting the skin after breast cancer and in metastases) is added to this classification. The classification proposed by Unna is based chiefly on the histological structure of the growth, and in the fungat- ing form the macroscopic appearance of the tumor is considered as well. To one unfamiliar with the histological details of carci- noma of the skin the classification is too involved for practical purposes. A further reference will be made to it in describing the minute anatomy of these new growths. To avoid confusion in the clinical picture of the malady certain primary types of more or less uniformity will be described, and then reference will be made to the forms which follow or develop on some pre-existing morbid condition of the skin or constitute the final stage of such affections, as xeroderma pigmentosum, Paget’s disease, lupus vulgaris, syphilis, ete. An important fact to be borne in mind is that carci- nomata of the skin are not infrequently multiform in their manifestation and often have a relatively benign course. Superficial Epithelioma.—One of the most frequent forms in which carcinoma of the skin begins is as a small, hard, pearly gray nodule generally found on the upper two-thirds of the face in individuals over forty years of age. These nodules are often multiple, may re- main for years with little or no change, or even may dis- appear spontaneously. If they are removed during their primary stage before ulceration begins they show only a slight tendency to recur. ; *** Les Cancers Epithéliaux,’’ Paris, 1898. + Unna, “ Histopathology of the Diseases of the Skin,” p. 670. : : REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Carcinoma, [Skin, Carcinoma of the After a time one or more of these small growths may slowly increase in size, the centre at the same time sink- ing in and eventually becoming fissured or excoriated as the result of scratching or other irritation. At this stage, the new growth consists of a superficial ulcer covered with crusts made up of blood and secretions from the affected surface, and surrounded by a hard, elevated, waxy looking margin (Fig. 1, Colored plate XXI.). The central ulceration may heal but is sure to recur, each time becoming somewhat larger, but seldom involv- ing the deeper tissues; it hasared, granular base, secretes but little pus, and rarely causes pain. The floor and edges of the ulcer, consisting of soft friable tissue ex- tending beneath the overlying epidermis, are easily re- moved by the curette. Instead of extending in a regular and progressive manner the ulceration may heal in the centre while continuing to spread at the margins, or one side may cicatrize, asa result of which gyrate and irregu- larly outlined ulcers with new foci may develop in the scar tissue (Fig. 1135). Such a carcinomatous ulcer may Fig. 1135.—Superficial Epithelioma of the Face (Rodent Ulcer Type) of Fifteen Years’ Duration. Showing scar tissue and peripheral ulceration. generally be differentiated from syphilitic or lupous ul- ceration by the presence of the elevated, waxy, or pearly gray margin. The progress of the affection is excessively slow, last- ing ten, twenty, or even forty years before the patient dies from this or some other malady. It may even- tually, however, invade the orbit, destroy the greater part of the skin of the face, the malar bones, the upper jaw, and penetrate the skull, causing the death of the patient from hemorrhage, exhaustion, or the involvement of vital organs. Fungating tumors reaching a consider- able size may spring up from these ulcerating surfaces. This variety of malignant growth, which has its pri- mary seat near the eye, beginning as a minute, pearly gray nodule and spreading in a slow but progressive manner, is the so-called rodent or Jacob’s ulcer, regarding the na- ture of which there has been so much discussion and di- vergence of opinion. It seldom or never invades the lymph nodes, and does not produce metastases or give rise to cachexia. It waslooked upon by the older writers, such as Brodie and Paget, as a disease distinct from carcinoma and some modern authors even now deny its carcinoma- tous nature. Probably several varieties of superficial skin carcinoma during their course may assume the ap- pearances described, so that the name, if retained, should be used in its clinical significance rather than to indicate a distinct species of epithelial new growth. Unna, on the other hand, opposes the view that every flat, superficial, carcinomatous ulcer should be called rodent ulcer. He believes that the latter affection has certain definite clinical as well as histological features which are characteristic, and that it should not be confused with other varieties of carcinoma. In addition to the early lesion in the form described, epitheliomata about the face may begin as brownish-red tubercles, hemispherical in outline, quite smooth, and of medium consistence. When first observed they are smaller than a split pea, slightly elevated, and may reach the diameter of half an inch before breaking down. These small nodules are readily scraped away with the dermal curette and apparently show little tendency to recur. They are seen about the ala of the nose, the eye- lid, and the forehead. Sections of such growths under the microscope are found to contain proliferating bands, tubular processes, and acinous-shaped masses of small epithelial cells which correspond to those in the basal layer of the epidermis. These proliferating tracts and masses of cells are surrounded by a layer of columnar cells which represents the basal layer and probably limits their rapid growth. They are enclosed in a loose mesh- work of connective tissue which is generally poorly de- veloped or may be almost absent. If undisturbed these nodules grow slowly for a num- ber of years, then, under the stimulus of some irritant, in- crease more rapidly in size, finally resulting in open ulcers. Disseminated Epithelioma of the “ Sebaceous Type.” — Multiple epitheliomata which are met with especially about the face, sometimes on the hands and trunk, are usually preceded by certain definite changes in the skin to which the name “senile keratosis” has been applied. The skin at first becomes somewhat rough, and is cov- ered by scales adherent to the follicular openings. Later, scabby concretions of a dirty yellowish-brown color form, and beneath them is found a warty condition which bleeds readily on slight irritation. Small cup-shaped depres- sions are subsequently noted beneath the thickened and altered horny layer; these coalesce and give rise to open epitheliomatous ulcers having hard, elevated edges and bases. A number of years may elapse from the time when the first changes in the skin appear before a malig- nant development takes place. The same patient is frequently affected with several epi- theliomatous ulcers in different stages of growth as well as with encrusted papillomatous areas which have not yet undergone the malignant change. The severer cases occur among those patients who are exposed to vicissi- tudes of weather and to the heat of the sun and in whom the earlier alterations in the skin which predispose to the condition are overlooked or neglected. Other senile changes in the skin, as pigment deposits, papillomata, alterations in the blood-vessels, atrophy of the subcutaneous connective tissue, predispose to malig- nant new growths. These changes are allied to those which occur in the young in a more aggravated form, constituting the disease known as xeroderma pigmento- sum, which, as a rule, terminates in the development of one or more malignant tumors. They are also met with in the condition known as sailors’ skin, which Unna* has observed and investigated. The changes which take place on the exposed portions of the face and hands are at first a cyanotic redness, followed by pigment deposits and leucodermatous spots. Localized thickening of the horny layer of the epidermis next occurs, and this, at certain spots, assumes a warty character, to be followed by papillary and ulcerating epitheliomata. While in their early stages these ulcers pursue an indolent course, and involve only the superficial tissues; at a later date they are more rapidly destructive than the rodent ulcers. In Paget’s disease of the nipple a superficial, moist, crusted, slightly scaling dermatitis may exist for a number of years as a precancerous condition. Healing cannot be brought about by the ordinary applications and eventually a superficial or deep-seated carcinoma appears in or beneath the chronic dermatitis. It is usu- ally of the alveolar type, and more frequently begins in the lactiferous ducts than in the epidermis itself. Swell- *Unna, “Histopathology of Diseases of the Skin,” p. 719. 681 Carcinoma of the Skin, ing of the lymph nodes is met with in the later stages of the disease. Multiple epitheliomata at times develop on old patches of psoriasis. The prolonged use of arsenic in this and other chronic skin diseases is at times followed by patches of keratosis and horn-like lesions especially on the palms of the hands and soles of the feet, beneath which can- cerous ulceration begins. These malignant changes are usually multiple, and in fifty per cent. of the cases re- corded they developed before the age of forty. Among arsenic miners carcinoma, beginning as arsenic warts on the fingers, has not infrequently been observed. Hutchinson has repeatedly called attention to the etio- logical relationship supposed to exist between the internal use of arsenic and the development, on the palms and soles, of keratoses which terminate in carcinoma; and lately Hartzell* has reviewed the subject, giving at the same time the report of a case of his own which showed this sequence of development. Chimney-Sweeps’ Cancer of the Scrotum.—This variety of cancer, which at one time was often met with in Eng- land, has become less frequent since the enforcement of laws forbidding sweeps to ascend flues. The retention of soot in the folds of the scrotum gives rise to a chronic dermatitis and warty outgrowths. After a time one or more of these warts ulcerate and eventually involve the superficial as well as the deep tissues. The inguinal lymph nodes after a time become implicated. Tar and Paraffin Cancer.—Volkmann + first called at- tention to the occurrence of cancer of the scrotum and forearms in workers in coal tar and paraffin. The an- tecedent changes in the skin are similar to those met with in chimney-sweeps’ cancer. The follicular open- ings are occluded, the skin becomes dry, thickened, and the seat of warty growths which subsequently become malignant. It isnot improbable, as has been suggested by Esmarch and Langenbeck, that tobacco, soot, tar and paraffin are closely allied in their power to stimulate epithelial growth. Abnormal cell division has been experimentally produced by treating the dividing cells with poisons and chemical agents, thus rendering more probable the relationship which is believed to exist between the long-continued use of arsenic and the development of cancer, and at the same time favoring the view that this variety of new growth may owe its origin to the stimulation furnished by such chemical agents as tobacco, tar, etc. Chronic affections of the derma, as lupus, syphilis, etc., seem to favor the development of carcinoma by lessening or removing the normal barrier which sep- arates the epithelium from the connective tissue. At the same time a constant irritation is exerted on the epithelial layer which causes it to undergo hypertrophy and ultimately may lead to its becoming the seat of a malignant growth. Carcinomata develop from active lupus or from its scar tissue so frequently as to indicate more than an accidental relationship. They are apt to assume fungating forms, to prove rebellious to treatment, and to pursue a more rapid course than when they develop independently of such a connection. They have also not infrequently been observed to start from late syphilitic lesions of the skin, in which case there is danger that they may be over- looked because the original disease often obscures their characteristic features. Syphilis of the tongue is one of the most frequent precancerous affections of this organ. Late syphilitic neoplasms, interstitial glossitis, and leucokeratosis may be followed by rapidly growing carcinomata. Indifferent scar tissue of the skin, when exposed to long-continued irritations, forms a favorable soil for the development of a malignant tumor. The course of such growths is less rapid than when they start from the scar-tissue of lupus. In the latter case there is nearly always more or less ac- *‘* Epithelioma as a Sequel of Psoriasis and the Probability of its ee Origin.”” The Amer. Jour. Med. Sci., vol. exviii., 1899, p. 265. + Beitrage zur Chirurgie, 1875, p. 380. 682 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tive tuberculous disease and thus less resistance is offered to the epithelial ingrowths. Papillary Carcinoma. — Papillomatous tumors bear much the same relationship to epitheliomata as the ade- nomata do to glandular carcinomata. They consist of a rapid growth of the cells comprising the Malpighian layer with a consecutive hypertrophy of the papille beneath. As long as the basement membrane remains unimpaired the invasion of the underlying tissues by the growing epithelium is prevented. Papillary growths frequently spring up from the base and periphery of carcinomatous ulcers, especially when a mucous membrane is involved, and obscure by their rapid development the features of the primary tumor. The scalp is sometimes the seat of these secondary growths (Fig. 3, colored plate XXI.), which assume a cauliflower-like appearance and convey the impression of a more malignant tumor than is warranted by their clinical course. These outgrowths are usually broader at their surface than where they are attached to the mor- bid growth, and they spread over the healthy skin in a radiating manner for a considerable distance. The seats of predilection of a primary papillary carci- noma are the glans penis and the lips. An absence of a firm epithelial covering facilitates the surface growth of the prickle layer (Unna). The horny layer may in the early stages be thickened and firmly attached, but, later, cornification becomes abnormal, and the enlarged papilla with the rapidly growing and unprotected prickle cells, bleeds readily on slight irritation. Surface infection takes place with consecutive necrosis of the superficial layer of cells. As long as the epithelial proliferation is superficial, these growths are easily removed. When the deeper tissues are invaded they spread at times with alarming ra- pidity owing to their active cell-growth. Sooner or later ulceration takes place and the early features of the affec- tion may be lost. In Fig. 2 of the accompanying col- ored plate a carcinomatous ulcer is depicted which began as a wart, but at the time when the picture was taken the papillomatous growth had entirely disappeared. These carcinomata differ from the growths of the ro- dent-ulcer type in their tendency to form horny or hya- line pearls as well as in their more rapid and malignant course. Cutaneous horns are modified papillomatous tumors in which cornification is greatly exaggerated. Epithelio- mata sometimes start from the base of such growths and terminate in open ulcers, which pursue the ordinary course of the malignant new growth. Carcinomata from Nevi.—Pigmented and non-pig- mented moles often present the structure of an alveolar carcinoma, and while the great majority of such con- genital malformations retain their benign character, they occasionally give rise to growths of great malignancy. Unna* and Gilchrist + have shown that these nevi are caused by the snaring off of epithelium from the surface epidermis in embryonic life or in early youth. Malig- nant tumors arising from such a matrix later in life are therefore carcinomata and not sarcomata, as has been so long held by the majority of pathologists. It has not been clearly determined that all malignant melanotic tumors are carcinomata, but if certain of these are of mesodermic origin it is impossible to differentiate the two classes clinically. These melanotic tumors may develop on any part of the body, generally on the ex- tremities or genitals. They are at first bluish-black or slate-colored growths assuming wart-like or fungous forms. : Secondary tumors may develop in the vicinity of the parent growth, and, spreading along the lymphatic ves- sels, give rise to large nodular growths in the lymph nodes. Metastatic tumors rapidly form in the viscera, and cachexia soon appears, followed by a fatal termina- tion, sometimes within a few months after the appear- ance of the primary tumor. * ‘* Histopathology of Diseases of the Skin,”’ p. 745. + Journ. of Cutan. and Genito-Urinary Dis., vol. xvii., p. 117. EXPLANATION OF PLATE XXII. - < ll fi - 413 , > a ‘ee fa y ¥ + _ ¢ Fic. Fig. Fia. EXPLANATION OF PLATE XXI. (Illustrating Dr. Fordyce’s article.) The colored pictures have been copied from photographs of author’s cases. 1.—Early stage of superficial epithelioma of the face, the so-called rodent-ulcer type of the affection. ; In this variety of epithelioma the new growth is made up of small epithelial cells which cor- respond to those in the basal layer of the epidermis or in the outer root-sheath of the hairs. The growth began in this case as a small pearly-gray nodule which slowly ulcerated in the centre while spreading with an elevated margin. The progress of this type of epithelioma is exceedingly slow. 2.—A more advanced stage of epithelioma of the skin. The growth here portrayed is of eight years’ duration. It beganas a wart which rapidly spread after the application of some caustic. The post-cervical lymph nodes were enlarged. The microscope showed the tumor to be a squamous-celled epithelioma, the prognosis of which is more grave than that of the rodent- ulcer type. 3.—The tumor here shown was seen when fully developed on the scalp of an old woman. It was attached by a broad peduncle, its margin resting on the healthy skin. The body of the growth was made up of moist, warty vegetations which readily bled on slight irritation. Under the microscope the tumor was found to resemble an alveolar carcinoma, the connective- tissue framework being rich in newly developed blood-vessels. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. PEATE XX. : z oa Re ail FIG. 1. EARLY STAGE OF RODENT ULCER OF THE FACE. ; FIG. 3. PAPILLARY OUTGROWTH WHICH DEVELOPED ON EPITHELIOMA OF THE SCALP. CARCINOMA OF THE SKIN. J a 5 H a * r ‘ os ~~ —— De . = ae - 4, b ia at -. » < a a , . = 4 es "4 7 > be bs , 4 = F ‘ "y 5 : ti 4 \ ; ; : : ms 4 . : on, = LIBRARY ‘OF THE UNIVERSITY of ILLINOIS. -— , © ~ . ty * ' * a te " ‘4 an j : ‘ 7 m J , rs i r a * f _ . 7 @ : * " Tre : "REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. — eS Carcinoma of the Skin, Deep-Seated or Nodular Carcinoma.—The great majority of cutaneous cancers conform to one or more of the types which have been described and are in their early stages more or less superficial. Many preserve such a location during their entire evolution, the new growth ulcerating as soon as it develops. Othersmay early tend to involve the deeper tissues, giving rise to distinct indurations or veritable tumors which invade the muscles or bones. The deep-seated or nodular carcinoma is, therefore, usu- ally secondary to a surface ulceration, but it may occur near the cicatrices of former operations for malignant dis- ease, a group of cells in the subcutaneous tissue acting as a focus for the relapsing growth. Metastatic cancers of the skin from visceral or breast carcinoma are usually first detected as small subcutane- ous nodules which, in exceptional cases, may enlarge, assume an irregularly rounded shape, and become firmly attached to the underlying tissues. Certain carcinomata of the surface epithelium, more especially of the tongue and lip, show an early tendency to deep infiltration and are apt to pursue a more malig- nant course from the beginning. The only plausible ex- planation that has been given as to why these growths tend to involve the deeper structures, is, that the down- ward growth of the epithelium can take place more readily in these localities where the tissues are rather succulent. Fabre-Domergue, however, attributes their more malig- nant course to the character of the new cell growth, which is favored by the absence or non-continuity of the basal layer about the masses of growing epithelium. In carcinoma of the tongue there is little or no disposition on the part of the epithelial cells to form concentric globes containing horny or hyaline masses, but the con- stituent cells grow, multiply, and end their existence independently and simultaneously. There is, conse- quently, in these tumors of the tongue an absence of those histological features which limit cell growth in many of the surface epitheliomata. Deep-seated epitheliomata, when primary, may begin as single or multiple pea-sized nodules of a whitish or purplish color. They increase slowly in size, become more irregular in outline, and form adhesions to the overlying skin. Eventually there is produced a firm, projecting tumor, which may reach the size of a hen’s egg, over which dilated blood-vessels are prominently seen. Ulceration subsequently takes place, leading to the formation of cavities which increase in a progressive manner as the infiltration spreads and breaking down of the tissues occurs. Papillomatous growths sometimes spring up from the base or walls of the ulcerating surface, the edges of which may contain waxy nodules like those seen in the superficial varieties. The lymph nodes may be involved at a comparatively early period and metastases may de- velop in the internal organs; then follow marasmus and death. Under the name of tuberose carcinoma cases of this kind have been described in which multiple, deep-seated tumors developed simultaneously and broke down into ulcers which soon led to the patient’s death. Carcinomatous Lymphatic. Infarction.—This is the name given by Unna to a sub-form of cancer of the skin. It is generally described as lenticular carcinoma. It is met with, in the great majority of cases, in the skin covering the female breast as a development secondary to mam- mary carcinoma; it may also develop in the cicatrix fol- lowing operation for cancer of the gland. Epithelial cells from the primary growth are conveyed by the lymph vessels and give rise to the formation of small white or pinkish papules from the size of a small shot to that of apea. Infiltrated patches at times result from the con- fluence of numerous primary nodules which may or may not undergo ulceration. When the lymphatic infection is active and extensive the entire cutaneous surface over the front and Wack of the chest may be involved, the process even extending to the skin of the abdomen and arms. In the later stages the skin becomes hard and leathery in consistence from the growth and contraction of the connective tissue, pro- ducing the condition known as cancer en cuirasse. The constriction produced by the new growth may be sufficient to interfere with respiration or may give rise to edema of the arm from interference with the lymph circulation. A fatal result may follow within a few months after such a development occurs, but in certain cases general infection is delayed for a number of years. Carcinoma of the Sweat Glands.—The most divergent opinions exist as to the réle played by the sweat glands in tumor production. Certain pathologists at various times have attempted to show that many small-celled epitheliomata, in which the cells grow in tubular proc- esses, have such an origin. It has, however, been clearly demonstrated that neither the shape, size, nor arrange- ment of the cells furnishes sufficient criteria on which to base the diagnosis of sweat-gland cancer. Darier* has re- ported a peculiar case that occurred in the service of Bes- nier, in which multiple, deep-seated, and painful tumors developed with great rapidity on the trunk of a man aged seventy-one. Darier’s examination showed that each tumor started with a proliferation of the sweat-gland epithelium, which filled the lumen of the canal, broke through the membrana propria, and infiltrated the con- nective tissue. He gave to his case the name “ diffuse multiple epithelioma of the sudoriparous glands,” and believed it to be unique in the number, the rapid evolu- tion, and the structure of the tumors. The author was able to find but two analogous cases in medical literature, one of which was reported by Malherbe, the other by Creighton. In the latter case a dog was the subject of the affection. In Darier’s case death resulted within a few months after the beginning of the affection. The author of the present article some years ago ex- amined a tumor which had been removed by Dr. Bronson from the anterior surface of the leg of a man thirty-five years old, and which proved microscopically to be a car- cinoma originating in the coil gland. The growth in question was composed of distinct lobules, separated by the ingrowth of connective tissue; it was soft to the feel, about half the size of a small egg, and defined from the surrounding tissue without being distinctly encapsulated. It extended about one inch below the skin, and measured an inch and a half in its long diameter. An open ulcer, somewhat larger than a dime, was present over the tumor. The cancerous nature of the new growth was not sus- pected prior to the microscopic examination. Neither the duration of the tumor nor its onset as a surface or deep affection was noted. Carcinoma of the Lip.—Cancer of the lip, by reason of its frequency, malignant course, and the importance of an early diagnosis, demands a separate consideration. Its seat of predilection is the lower lip, at the junction of the skin and mucous membrane near the median line. It may occur near the angle of the mouth. The develop- ment of a tumor on the upper lip has been noted in one or two instances. In these cases contact with the primary growth on the lower lip may have served as a cause. Cancers of the upper lip, as a rule, occur at some dis- tance from the vermilion border and are usually of the rodent ulcer or superficial type of growth. When the mucous membrane is involved by the extension of such a tumor of the upper lip its clinical course differs from that of the typical cancer of the lower lip. It does not penetrate deeply nor infect the lymph nodes as in the latter case. A number of primary changes in the surface epithelium may precede ulceration or tumor formation. Hyperker- atosis over a limited area, followed by a fissure and later by ulceration, is often observed. The ulcer is irregular in outline and surrounded by thickened and elevated mar- gins (Fig. 1136). The base of the ulcer becomes indu- rated and the infiltration gradually extends to the deep- est issues. In another case the epithelium may become eroded in- *** Contributions a l’étude de l’épithéliome des glands sudoripares.”” Arch. de méd. expérimentale et d’anat. pathol., 1889, pp. 115, 267. 683 Carcinoma of the Skin, “REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. stead of thickened and covered by closely approximated granulations which enlarge until they assume a warty character. This papillomatous growth may spread lat- erally until almost the entire lip is covered with granula- tions before deep extension takes place. Instead of the ragged ulcer which is portrayed in Fig. 1137, a shallow, Fig. 1136.—An Early Stage of Cancer of the Lip. Showing super- ficial ulceration. oval and regularly outlined loss of tissue may constitute an early form of lip cancer (Fig. 1186). (Figs. 1136 and 1137 are reproduced here by the kind permission of the New York Medical Journal.) Changes in the epidermis may be overlooked and the patient’s attention may be first directed toa hard growth below the surface. This soon ulcerates, leaving a cavity surrounded by hard walls and base from which the de- generated epithelial cells forming the centre of the epithe- lial “ pearls” may be squeezed out as comedo-like bodies. In neglected cases the infiltration and ulceration in- volve the entire lower lip and the floor of the mouth; the teeth become loosened and all the adjacent tissues are de- stroyed. The submaxillary and submental lymph nodes are involved, as arule, before such extensive tissue de- struction occurs. The average duration of life in un- treated cases is from three to five years, death taking place from sepsis or metastasis. Cancer of the lower lip occurs in about fifty per cent. of surface epitheliomata. The male sex furnishes an overwhelming percentage of all cases, variously estimated at from eight to one to twenty to one. Statistics show that the large majority of those so afflicted are addicted to the use of tobacco, and of the few cases met with in women three-quarters were smokers. Diagnosis.—The initial lesion of syphilis is often mis- taken for cancer of the lip. Chancres of the lip are usu- ally protuberant with an eroded or encrusted surface; they develop rapidly and very early involve the lymph nodes. The initial sore of syphilis is more likely to be met with in young adults, while epithelioma is a disease of later life. Numerous exceptions to these rules, however, are found. Late ulcerating syphilides of the lip have also been mistaken for cancer, but these neoplasms of syphilis are usually multiple, rapidly break down or undergo ab- sorption with atrophy, and lack the hard base which is always present in cancer. In a doubtful case appeal should be made to the microscope. Prognosis.—The course of carcinoma of the lip is much more rapidly fatal than is that of the flat variety of epi- 684 thelioma of the skin. An early and radical excision by the knife is the only method of treatment which promises subsequent immunity to the patient. Ifthe operation is performed while the affection is superficial the outlook is not unfavorable. Even in such cases early operations sometimes fail to prevent general infection. PATHOLOGY AND Morsrp ANATOoMy.—Carcinomata of the skin in the great majority of cases start from the surface epithelium or the epithelium lining the hair folli- cles. The sebaceous and sweat glands only exception- ally are primarily implicated. It is not possible in all instances to associate a definite clinical type with a fixed histological structure. Unna’s plan of classification, which reduces the major- ity of skin cancers to a few types according to the archi- tecture of the growths, involves the mutual relationship of the growing epithelium to the resisting connective tissue. A proper presentation of his views would in- volve an extended discussion, which is scarcely in place in this connection. A distinction of some clinical as well as pathological importance is that which separates these new growths of epithelium into two groups, in one of which the cells are chiefly of the squamous variety, while in the other they are of the small or columnar type. As a rule the squamous-celled epithelioma is found about the muco-cutaneous orifices, more readily involves the lymph nodes, and is more malignant than the small-celled variety of the disease. The difference in malignancy between these two types of growth is perhaps not so decided as it was at one time believed to be. Squamous-celled epitheliomata are seen at a distance from the orifices. They may persist for a period of ten years without invading the lymph nodes, and then ex- ceptionally the rodent-ulcer type of growth is met with in which the communicating lymph nodes are involved. We are as yet ignorant of the factors which render rodent ulcer a relatively benign affection and the squa- mous-celled epithelioma a more malignant growth. ‘The superficial seat of rodent ulcer and the early occurrence of ulceration are supposed by some writers to prevent the absorption of the cells by the lymph vessels. The resisting power of the connective tissue, which in rodent ulcer early assumes a structure like that met with in Fig. 11387.—Early Form of Cancer of the Lip. A shallow concave ulcer near angie of the mouth. scirrhous cancer, is looked upon by Unna as an important factor in determining the clinical course of the affection. Although the new growth of epithelium which we see in rodent ulcer isalways made up of small cells which correspond to those in the basal layer of the epidermis or the outer root sheath of the hair follicle, it is possible that there are a number of other clinical varieties of small- - , REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Carcinoma of the Skin, celled skin cancers which are not identical, at least clini- cally, with rodent ulcer, Carcinomata of the surface epithelium, according to the classification of Fabre-Domergue, may develop in the direction of the adult type of cell, giving rise to cornifi- cation of individual cells or to rudimentary epidermic Fig. 1138.—From a Rodent Ulcer of the Face. Showing cylindrical processes of small epithelial cells surrounded by a basal layer, (Spencer one-quarter inch, projection ocular 2.) “ globes, ” between which type and the true epitheliomata there are many transitional forms. They may further- more assume the embryonic type of growth and simulate so closely glandular carcinomata that it is not always possible to differentiate them by their: histological struc- ture. In carcinomata of the adult there are, beside the em- bryonic type of cell, the same tendency to general cell activity throughout the growth, a non-continuity or absence of the basal layer, and consequently in both the same tendency to deep infiltration and general infection. The clinical gravity of the tumor depends, therefore, on its structure rather than on its location. The embryonic epithelioma (Fabre-Domergue), the tu- bular epithelioma of Cornil and Ranvier, and the small- or columnar-celled epithelioma correspond in all essential points and are identical in structure with rodent ulcer in its earlier stages. The tumor originates from the lower- most layer of the rete Malpighii or from the outer root sheath and preserves with rare exceptions its embryonic cell structure throughout its entire course. The new growth of epithelium develops in the form of cylindrical processes throughout the lymph spaces of the derma (Fig. 1188). It is preceded by the appearance of a dense mass of mononucleated leucocytes (plasma celis, Unna). The connective tissue between the masses of growing epithe- lium becomes thickened and sclerotic and probably limits the down growth of the cylindrical processes, which may later assume elongated shapes owing to the greater resistance which they encounter. The tubular processes of young epithelium are sur- rounded, in the earlier stages of the process, by a layer of cells which correspond to the basal cells of the epi- dermis (Fig. 1138). As the affection extends it is more difficult to identify this layer and it finally disappears. The loss of this protective layer is probably one reason for the more rapid extension of the growth in its later stages. No good reason has as yet been advanced why the lymph nodes are not involved in rodent ulcer unless it is owing to the greater resistance interposed by the connec- tive tissue. That they may exceptionally become in- fected was shown in a case which recently came under the observation of the writer. A patient, sixty years old, presented a typical rodent ulcer, of ten years’ duration, on the side of the nose, extending to the inner canthus. He had at the same time, behind the ear, an epithelioma with identical clinical features. The lymph node over the mastoid process was enlarged and after excision was found to be invaded by typical cylindrical processes of epithelium which could not be distinguished from those in the derma. The exceptional situation of the epithelioma in this case, at a point where the integument is thin and where the growth was subjected to pressure against the under- lying bone, was probably the factor which determined the invasion of the lymph node in the immediate proximity. Sweat-Gland Cancer.—The case of sweat-gland cancer which came under the observation of the writer and to which reference has been made, had the following histo- logical structure: Under a low power the derma was found to be the seat of numerous bands, masses, and gland-like arrangements of small epithelial cells which extended from beneath the epidermis to the subcutaneous connec- tive tissue. They differed in their arrangement from that met with in other varieties of skin cancer, and sug- gested to the observer an attempted reproduction of glandular tissue. Under a higher amplification a com- plicated network was seen; it was formed by the inter- lacement of bands of epithelial tissue enclosing cavities which were partially or completely filled with degen- erated cells or with a homogeneous substance allied to colloid matter. Cyst-like cavities were found in other parts of the microscopic field. They were lined by a single layer of columnar epithelial cells, and presented a striking resemblance to overgrown sweat ducts. Fig. 1189 represents a group of enlarged and proliferat- ing sweat ducts cut transversely. The columnar shape and regular arrangement of the peripherally located cells are well shown, These cells are situated upon a base- ment membrane, and are an almost exact reproduction of those normally met with in the sweat glands, although here very much hypertrophied. The lumen of the tubules is completely filled by the growing and multi- Fig. 1139.—From a Cancer of the Leg. Showing a group of enlarged and proliferating sweat ducts cut transversely. Spencer one- quarter inch, projection ocular 4.) plying cells, and in places the basement membrane is penetrated and the surrounding connective tissue in- fected by them. The other anatomical structures of the skin were not implicated in the cancerous process, neither was there any evidence of a tendency to cell-nesting or the formation of epidermic “globes.” The epithelial processes met with in the small-celled carcinoma of the 685 Cardamom, Cardiac Depressants, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. skin, starting in the rete Malpighii, resemble to some ex- tent the cell arrangements observed in the case under consideration. In the epidermic cancer, however, the cells are larger, and do not rest upon a distinct basement membrane, as in this case. Furthermore, the epithelial bands or tubules starting from the rete have no distinct calibre, and do not reproduce so perfectly the glandular structure. Errotogy.—The development of cancer of the skin is favored by a number of antecedent conditions to which reference has been made under Symptomatology. Ina general way the statement is true that chronic irritation of slight intensity is one of the most potent factors which precede the malignant change in epithelial growths. The origin of highly malignant tumors from certain con- genital moles has given some support to Cohnheim’s theory of latent embryonic “remains.” In xeroderma pigmentosum a congenital weakness of the skin is pres- ent which strongly predisposes to malignant growths. Heredity probably has some influence in favoring the evolution of some forms of malignant disease. Inflammatory changes in the papillary region of the derma, by impairing the integrity of the basement mem- brane, favors the downward growth of epithelium. Atrophic changes in the connective tissue in advanced life exercise a similar influence. The advocates of the parasitic origin of cancer consider the association of the malignant affection with pre-exist- ing lesions as accidental. According to them the changes in syphilis and other chronic skin diseases merely furnish a favorable soil for the superadded infectious agent. Cancer of the skin is more frequent after the age of forty, though no time of life is exempt. Kaposi has ob- served itanumber of times between the ages of eight and eighteen. Rodent ulcer begins, as a rule, about the age of forty, but it may make little or no progress for several years. DraGnosts.—Superficial cancer of the skin is frequently mistaken for late syphilitic infiltration and ulceration or for lupus. These late nodular and ulcerative syphilitic lesions are usually more rapid in their evolution and in- volution, are frequently multiple, and lack the char- acteristic elevated and waxy border which distinguishes malignant ulceration. When syphilitic ulcers or those of lupus are complicated with epithelioma the diagnosis is more difficult. Lupus generally develops early in life, pursues a chronic course, and spreads on the margins of the patch by brownish-red nodules deeply embedded in the skin. These nodules or tubercles are as characteristic of lupus as the waxy margin is of superficial epithelioma. Tuberculosis verrucosa cutis might be mistaken for papillary cancer of the fingers or hands. Induration about the base of a wart or cutaneous horn should excite suspicion of a malignant change. In case of doubtful diagnosis resort should always be made to the microscope. Proenosis.—In superficial cancer of the skin the prog- nosis is more favorable than in any other form of the dis- ease, as the progress is slow and the lymphatic system seldom implicated. If the growth is radically removed in its early stages there is little tendency to recur. Cancers from moles are decidedly malignant, as they early involve the lymphatics and may soon be followed by a general metastasis. Papillary cancers are usually rapidly growing, and when they infiltrate the deeper parts, if not removed, lead to a fatal issue within from one to three years. Rodent ulcer in its later stages almost invariably re- turns after removal, though preserving its local seat. It is well to bear in mind that a superficial growth may become deep-seated and pursue a rapidly fatal course, as in the galloping or phagedenic epithelioma described by Besnier. TREATMENT.—Early and complete extirpation with the knife is the only method of treatment that should be employed in cancer of the mucous membrane of the mouth, or of the lip. On other parts of the body, as the neck, scrotum, etc., 686 when the skin is freely movable and union by first inten- tion can be secured, an excision offers the most rapid, painless, and satisfactory method of cure. If the opera- tion is resorted to before the lymph nodes are invaded and if the incisions are made at a sufficient distance from the morbid growth, a cure may be looked for in the ma- jority of cases. Associated lymph nodes when invaded should be re- moved in as thorough a manner as possible. Partial removal of cancer of the skin, even the most. superficial, by the knife, curette, or caustics, accom- plishes no good result and frequently stimulates these new growths to increased activity. Superficial cancers of the skin are sometimes so situated that a cutting operation is followed by more deformity than after the employment of curettage and caustics. Many patients are so prejudiced against any cutting operation that they will endure the more prolonged and painful action of caustics rather than submit to the use of the knife. Under these circumstances the diseased tissue may be scraped away with the dermal curette and some suitable caustic applied to the resulting ulcer. Numerous cures of cancer of the face have been ob- tained in this way by the writer, the caustics employed, as a rule, having been arsenic, in the form of Marsden’s. or Bougard’s paste, or pure chloride of zine. Arsenic is. perhaps the best of all caustics as it is more certain in its. action and presumably has a selective action on the mor- bid tissue. Marsden’s paste is made by mixing two. parts of arsénious acid with one part of powdered gum acacia and sufficient water to make the mixture of a firm consistence. Robinson, who has devoted much time and considera- tion to the use of caustics in the treatment of cancer, pre- fers to vary the strength and duration of the application according to the cancer to be treated. He uses the paste in the strength recommended by Marsden and somewhat weaker, but never uses less than equal parts of arsenic and gum acacia. The paste is applied somewhat beyond the diseased area and is left on for from eight to twenty hours (Robinson). If the desired destruction of tissue is. not obtained within the shorter limit a second but weaker application should at once be made until the necessary necrosis is accomplished. The advantages claimed for the caustic treatment of cancer are the lesser degree of deformity which results and the greater certainty of reaching foci of diseased cells in the lymph vessels outside of the parent growth. It is, however, painful, and the separation of the resulting slough is somewhat slow. Pain during the action of the caustic may be controlled by morphine, and the after-treatment should be conducted on the usual lines. Before scraping away the morbid tissue as preliminary to the use of the caustic agent, the parts may be rendered anzsthetic by aspray of chloride of ethyl. If this is fol- lowed by the application of tampons saturated in a five or ten per cent. solution of cocaine the slight surgical procedure may be rendered absolutely painless. Instead of employing destructive chemical caustics like arsenic and chloride of zinc the Paquelin or galvano- cautery may_be used to complete the treatment. The actual cautery is, however, not so certain to reach all the diseased cells as is the arsenical paste. Patients who. have been operated on for cancer should remain under observation for one or two years or longer, and the slightest recurrence should immediately be re- moved, i The internal use of arsenic for several months after the: removal of malignant tumors has, perhaps, some influ- ence in preventing or limiting recurrences. John A. Fordyce. CARDAMOM.—CARDAMOMUM. The fruit of Het- tarta repens (Sonnerat) Baillou (fam, Zingiberacee). Since: the seed is the only active part, the above definition should. be so restricted. The cardamom plant isa tall, reed-like, perennial herb, from six to twelve feet high. The flow- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Cardamom, Cardiac Depressants,. ers and fruits are borne upon special short, scaly stems, partly prostrate among the bases of the leafy culms. The plant is a native of Southern India, where also it has been long incultivation. It has been introduced into other tropical countries. The cardamoms of commerce are mostly the product of cultivated plants, which are grown in the moist shade, either in clearings of the nat- ural forests or in plantations of betel palms. The fruits are gathered before they are quite ripe. They are thor- oughly washed, partly with soap and partly with a solution of a saponace- ous fruit, and then bleached for some hours. They are frequently rubbed between the hands with a mixture of starch and buttermilk. They are ovoid or oblong, pointed, rounded-triangular, three-valved, and three- celled capsules. The husk, when dried, is of a pale yellowish-gray or brown, flexible, and tough. Those which have been starched have a white and almost chalky surface. The seeds, five or six in each cell, are irregularly compressed, brown, and spicy. The fruits of the best varieties are usually short, about once and a half or twice as long as broad (1 to 1.5 cm. = ;% to ;% in.), very plump and full. They are com- mercially called “shorts.” Others, longer and more angular, are denominated “short-longs” and “longs.” The larger and longer cardamoms are mostly the produce of other species of Elettaria, and are therefore unofficial. Their odor and taste are not so pleasant. In selecting cardamoms, the point of chief importance is to see that they are short, plump, and well-filled, as otherwise the proportion of husk is too great, and the strength is thus weakened through the diminution of the active portion. This difficulty can be avoided by specifying the amount of the seeds instead of the fruits. The seeds from un- filled fruits are themselves defective, however. Cardamoms are also distinguished, according to the countries or ports from which they are exported, as Malabar, Aleppo, Madras, etc. The former are the most esteemed. The seeds contain about five per cent. of a pale yel- low aromatic oil, of complex composition, which repre- sents them in odor and taste. The ash of cardamom is rich in manganese. Cardamom is a typical aromatic, and is usefulin all the conditions which call for articles of that class. As an agreeable flavor and appetizer, as a stimu- lant to digestion, and as a carminative in flatulence and in simple colic, it is sometimes, but not often, given alone. In combinations, as a pleasant and useful adjuvant and corrective, it is in more frequent use, acting favorably with cathartics, bitter tonics, stimulants, etc. But the principal use of cardamom is as a condiment or house- hold flavor, for which purpose, especially on the conti- nent of Europe and in the East, it is extensively em- ployed. It is also used in flavoring liqueurs, and in curry-powder, etc. It is Jess irritating than the spices proper, and more so than anise and the milder carmina- tives. The dose of cardamom as an aromatic by itself would be from .5 to1 gm. (gr. viij ad xv.). There isa ten-per-cent. official tincture which represents it com- pletely. The compound tincture contains two per cent. each of cardamom and cinnammon, one of caraway, five of glycerin, and one-half per cent. of cochineal, in diluted alcohol, and is given in doses of 8 to 15 c.c. (2 to 4 fl. 3). It also enters into the aromatic powder and the aromatic fluid extract. W. P. Bolles. CARDAMOM, OIL OF.—This term is understood as applying to the volatile oil, and not to the ten per cent. of fixed oil which the seeds yield. It is yielded to the extent of five or six per cent. It is of a pale yellow color, highly aromatic, has a specific gravity of about .900 and a rotation of +13°. Itsimportant constituent is terpinene (CioHis). Its properties are identical with those of cardamom. It is, however, chiefly used for fla- voring, especially liqueurs. Henry H. Rusby. Fig. 1140.—Malabar Cardamom. (Natural size.) “ CARDIAC DEPRESSANTS AND CARDIAC STIMU- LANTS.—I. Carpiac Drepressants.—The term cardiac: depressant is applied to drugs which lessen the force and frequency of the heart’s action and are employed for this purpose in therapeutics. Since all classes of verte- brates and many invertebrates are provided with a ner- vous mechanism (the cardio-inhibitory apparatus) through which such changes in the heart are brought about in the normal animal, we should expect to find that those drugs-which experience has shown to have the power of reducing the heart’s action would exert their influence through this mechanism. As a matter of fact, the two drugs which are most used for their depressing influence upon the heart, aconite and veratrum viride, do exert their influence through the cardio-inhibitory nerves. It is conceivable that the part affected by these drugs might be any point in this mechanism—the nerve centres in the medulla, the nerve fibres, which in the higher animals are contained in the vagi trunks, or that which is rather vaguely (since the exact anatomical elements are not. well known) termed the endings of the nerves in the heart. As is well known, nerve fibres are, as a rule, less. easily affected by drugs than are nerve cells or the termi- nations of nerve fibres; and no drug is known which is able to exert a special influence upon the cardio-inhibitory nerve fibres, although there are many which stimulate the nerve cells in which these fibres originate and also their terminations in the heart. There are, moreover, drugs which seem to increase simply the sensitiveness of the vagus terminations without actually stimulating them, or at least without stimulating them sufticiently to slow the heart; the increased sensitiveness may, how- ever, cause them to respond to a slighter stimulus than usual or with greater energy to a norma! stimulus. Another class of drugs, of which tartar emetic is a good example, depress the action of the cardiac muscle: directly and so have been used as cardiac depressants; but such drugs are not considered as safe as those which work through, so to speak, more physiological channels. In fact, the depression brought about by a direct action. upon the cardiac muscle is often associated with the con- dition known as collapse. For the sake of completeness it may be added that the heart’s action may be depressed by drugs acting in ways other than those just mentioned. Thus, if a drug causes a great fall of blood pressure the heart may be imper- fectly supplied with blood and beat very feebly and slowly. If the blood pressure be much increased by 3 drug causing contraction of the arterioles, the high blood pressure may act as a stimulus to the vagus centre and so depress the action of the heart. The vagus centre may be stimulated reflexly by drugs having a powerful local action; it may also be stimulated by the accumula- tion of carbon dioxide in the blood if some drug which interferes with the respiration has been given. Again, it is probable that there are drugs which can slow the heart by depressing the accelerator nerves. Since these nerves are in a condition of tonic activity, any interfer- ence with their activity would lead to a slower rate. While the most typical cardiac depressants exert their influence through the cardio-inhibitory mechanism, their action upon the organism is not by any means confined to this apparatus. Not only may many other functions —as, for instance, those of the central nervous system, the respiration, secretion, etc.—be influenced, but other parts of the vascular mechanism (the vaso-motor centres and nerves, the blood-vessels, the accelerator nerves of the heart, the cardiac muscle, etc.) may undergo changes which exert a profound influence on their action as car- diac depressants. In fact, a drug may stimulate the vagus and thus slow the heart and at the same time stimulate the cardiac muscle and in this way antagonize the effect of the vagus; sometimes one and sometimes the other effect will predominate. The condition be- comes much more complicated when the preparation used contains several active principles, each with its. peculiar action. For this reason it is desirable to use simple preparations and to determine as accurately as 687 Cardiac Depressants, Cardiac Depressants, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. possible all their effects; in this way reasons can some- times be found for the failure of the drugs to produce the desired effects under certain circumstances. The three drugs which have been used most exten- sively as cardiac depressants are aconite, veratrum viride, and tartar emetic. Aconite.—The action of aconite as employed in medi- cine is almost identical with that of its chief alkaloid, aconitine. Asmost of the physiological experiments have been made with the alkaloid, its action will be considered first, and then the manner in which the other substances present in the ordinary preparations of aconite influence its action will be discussed. Aconitine affects the circulation in three ways: it has a direct action upon the heart muscle, it stimulates the centre of the cardio-inhibitory nerves, and it influences the vaso-motor centre. With medicinal doses the second of these effects, the stimulation of the cardio-inhibitory nerves, is the most prominent and important and is the one desired in therapeutics. When aconitine is administered to man or to one of the other mammals the first effect upon the circulation is usually a slight acceleration of the heart. This is usually attributed to a direct action upon the cardiac muscles, al- though it is not improbable that in some cases the effect may be brought about reflexly through the local irritant action which the drug is well known to have upon the terminations of sensory nerves. This slight acceleration may be accompanied by a small increase in arterial press- ure. Theacceleration of the heart, which with mammals is never marked and does not always occur, is followed by a remarkable slowing and weakening of the heart beat. In man a pulse rate of 86 to 40 not uncommonly follows a moderate dose of aconite. In cases of poison- ing a still slower rate is occasionally seen; it is said to have been reduced to 10 per minute in one case. At the same time the pulse is much weakened. Sudden exertion at this stage may lead to a very rapid, irregular heart action and fatal syncope has occurred. Achscharumow (Archiv fiir Anat. und Physiol., 1866, p. 255) showed that this slowing of the heart is due almost entirely to a powerful stimulation of the centre of the cardio-inhibitory nerves in the medulla oblongata. Section of the vagi prevents the slowing in nearly every case. At times, however, there seems to be a slight stimulation of the peripheral endings of the vagi, for some slowing may ye observed when the drug is administered after section of the vagi; this slowing is abolished by atropine. This action upon the vagus terminals is of very slight im- portance in comparison with that upon the medullary centres; in fact, there is probably no drug which stimu- lates these centres as powerfully as does aconitine and has at the same time so little action, in small doses, upon other parts of the vascular mechanism, The amount of blood expelled by the heart under the in- fluence of aconitine is much reduced and the blood press- ure falls markedly. Some of the general symptoms of aconite poisoning are attributed to this fall of blood pressure. Thus there is a marked lowering of the body temperature, and this is usually ascribed to the depression of the circulation which leads to lessened oxidation and to an increased loss of heat from the surface of the body. Experiments of Brunton and Cash, however, indicate that there is also some action upon the nerve centres regulating the temperature of the body. The convulsions which frequently occur in cases of severe poisoning by aconite have been ascribed by some to the low blood pressure. While it is very probable that the latter is one factor in causing the convulsions, these seem to be due to a greater degree toa direct action upon some of the nerve centres, for convulsions occur in animals in which the fall of blood pressure is prevented by paralyzing the yagi with atropine. Moreover, there is ample evidence that several other parts of the medulla oblongata—the cardio-inhibitory, the vaso-motor, and the vomiting cen- tres—are stimulated by aconite, and it is very probable that the nerve cells causing convulsions are similarly stimulated, The severe dyspnea which is one of the 688 first symptoms of aconite poisoning seems to be depenaent to some extent upon the low blood pressure, for von Anrep (Archiv fir Anat. und Physiol., 1880, Supple. Bd., p. 180) found that if the blood pressure was raised by com- pressing the abdominal aorta the first symptoms of dysp- neea disappeared. Later there is a direct action upon the respiratory centre. The great muscular weakness so often observed seems to be due to anzemia of the spinal cord. The details of the action of aconitine upon the mam- malian heart have been recently studied by Matthews (Journal of Experimental Medicine, ii., p. 598) and Cash and Dunstan (Phil. Trans. of Roy. Soc., London, exce., p. 248). By the use of a modified. form of the Roy- Adami myocardiograph (an instrument by which the rate and force of the contraction of the cardiac muscle can be recorded) Matthews found that during the above, or first, stage of its action aconitine causes the following changes: the diastolic pauses of the ventricle are pro- longed, the systolic contractions are weakened, while the relaxations of the ventricle are little changed or are a little increased. The relaxations of the auricle are little affected, but the diastolic pauses are much longer than in the ventricle. The auricular systolic contractions are greatly weakened and in some experiments are entirely suppressed, the auricle remaining in diastole; in such cases the ventricle assumes a slow, spontaneous rhythm. If the drug be administered in small doses, the rhythm can be reduced to one-half or to one-third of its original rate and the blood pressure lowered to a corresponding degree. If the administration of aconitine be continued the heart beat becomes irregular and extremely rapid. Sometimes this effect is the first one seen in man, even after a moder- ate dose of the drug; it would seem that in such cases the cardio-inhibitory centre is not very irritable. The cause of this acceleration is frequently said to be the paralysis of the vagus terminations, but direct stimulation of the cardiac muscle seems to be a much more important factor. In fact, the effect of aconitine upon the peripheral endings of the vagi in the later stages of the intoxication has been a matter of considerable dispute. Some writers state that these structures are paralyzed, others that they remain intact, while a third group state that they may seem paralyzed at one instant and not at the next. Matthews has observed that sometimes stimulation of the vagus in the later stages of poisoning causes a change in the form of the contraction but no diminution in the rate. The explanation of the above results is probably that while the irritability of the vagus terminations is depressed that of the heart muscle is greatly increased so that inhibition is much more difficult. One reason why stimulation of the vagi causes slowing of the ventricle at one instant and not at the next may be found in the vary- ing irritability of the muscle fibres connecting auricle and ventricle; these may be in a condition to transmit impulses from the auricle to the ventricle at one time but not at another. Simultaneously with this acceleration, and often pre- ceding it, there appear marked irregularities in the rhythm of the heart. These irregularities affect both the strength and the rate of the heart beat; they will be dis- cussed somewhat fully here as similar irregularities occur after poisonous doses of many of the drugs acting upon the heart. At first, certain ventricular beats seem “missed ”; when the number of such beats increases, the rate may seem but half as fast as before; but closer ex- amination usually shows that there is an alternation of large and small beats and that only the former are dis- tinctly recorded. The blood pressure falls during these imperfect systoles. This period of alternate large and small beats may be followed by a very rapid but regular rhythm during which the extent of the contractions is very limited. The auricle departs but little from the position of diastole and the ventricle from that of systole. Then periods of rapid beats may alternate with periods of slow beats. So far the auriculo-ventricular rhythm may have remained unaltered, each beat of the auricle . REFERENCE HANDBOOK OF THE MEDICAL SCIENCES, C2®rdiac Depressants, being followed by one of the ventricle; but this rhythm is soon disturbed and contractions of the ventricle may occur independently of the auricle. The ventricular beat may dissociate itself entirely from that of the auricle and the two chambers beat independently of each other. At the same time there seems to be an effort on the part of the heart to maintain a simple ratio between the beats of the auricle and the ventricle; frequently this ratio is two to one or one to two—7.e., the ventricle beats one-half or twice as fast as the auricle. Sometimes, when no such simple ratio exists, if one chamber becomes accelerated the other may become slowed until such a ratio is estab- lished. Many varieties of pulse may develop during this stage; but they may at any time yield to a regular one fora brief period, and stimulation of the vagi or ac- celerators will usually bring about the same result. The chief cause of this irregularity seems to be an increase of the irritability of the cardiac muscle which enables the ventricle to beat independently of the impulses received from the auricle. Tworhythms (one ventricular, the other auricular) are thus established, and they may interfere with each other. The extent of this interference is deter- mined by the condition of the muscle fibres connecting auricle and ventricle and which transmit the impulses from one chamber to the other. As the intoxication continues the irritability of the cardiac muscle becomes greater and greater, and the ventricle contracts exceed- ingly rapidly and imperfectly and finally passes into delirium. These cardiac irregularities caused by aconite are antagonized to a considerable extent by atropine. The latter does not prevent the acceleration, but it reduces the tendency to arhythmia and tends to approximate the speed of the ventricle to that of the auricle when the auriculo-ventricular rhythm is disordered, and it averts or delays the very rapid and feeble action of the systole which is the precursor of death. In fact, atropine often enables the heart to stand several times the fatal dose of aconitine. Although the usual cause of death in aconite poisoning is failure of the respiration, it is necessary to pay attention to the condition of the heart, and probably as much good is to be expected from atropine as from any drug. ; The blood pressure is extremely irregular during the second stage of the action of aconitine. When the heart is very irregular the pressure falls to nearly zero, but it rises again during the periods in which the heart beats more regularly. It is also fairly high when some simple ratio is maintained between the rate of the auricular and ventricular beats and is lowest when the asequence of the two chambers is most marked. These sudden changes in the blood pressure are undoubtedly due largely to changes in the heart beat, but there is evidence that the vaso-motor centre is also affected. If atropine be ad- ministered to an animal in quantity sufficient to paralyze the vagus terminations, aconitine causes a rise instead of a fall of blood pressure. The cause of this rise of press- ure is usually considered to be a stimulation of the vaso. motor centre, but it is also stated that there is a constric- tion of peripheral vessels due to-a direct action of the drug upon their walls. In the second stage of poisoning the vaso-motor centre is depressed; asphyxia now causes but a slight rise of blood pressure, and the same is true of a stimulation of a sensory nerve (although in this case the possibility of the paralysis of the sensory nerve itself must be considered). The peripheral vaso-motor nerves remain intact, as is shown by the fact that stimulation of the medulla or of the splanchnic nerves causes a rise of blood pressure even late in the intoxication. Most preparations of aconite contain besides aconitine certain of its decomposition products, especially benza- conine and aconine. Benzaconine, which differs from aconitine only in that one acetyl group has been removed, has an action upon the heart having little resemblance to that of aconitine; in fact, it acts to some extent as an antagonist of aconitine. Instead of causing a great ac- celeration of the heart as do large doses of aconitine, it slows the heart, especially the ventricles, and if inco- ordination between auricle and ventricle is produced the Vou. I1.—44 Cardiac Depressants, latter beats more slowly than the former; with aconitine the opposite is usually the case. The slowing of the heart is due largely to a direct depression of this organ. It is not due toa stimulation of the inhibitory nerves, either centrally or peripherally, as it occurs after atropine. Aconine, which differs from benzaconine in that a benzoyl group has been removed, has an action just the reverse of aconitine. Instead of being a cardiac depressant it is a cardiac stimulant and strengthens the heart beat; the blood pressure rises and no disturbances of the rhythm are produced. In fact, it is an antagonist of aconitine and tends to prevent asequence of the auricle and ventricle by facilitating the transmission of im- pulses from one chamber to the other. It also opposes the tendency of the ventricle to go into delirium. The action of benzaconine and aconine is, however, so feeble in comparison with that of aconitine that it is im- probable that they do more than simply to weaken the action of the latter. It is due largely to these decom- position products that the preparations of aconite vary so much in strength. A number of other alkaloids derived from the Aconi- tum genus have been isolated, but they have at present little interest and their action upon the heart is not well known. Among these are pseudaconitine (the alkaloid of Aconitum ferox); lappaconitine, septentrionaline, and cynoctonine—all derived from Aconitum septentrionale ; and lycaconitine and myoctonine from Aconitum lycoc- tonum. In addition to these certain artificial derivatives of aconitine have been prepared recently and studied by Cash and Dunstan. Another alkaloid closely resembling aconitine, but one which is little known, is delphinine. It is found in Del- phinium staphisagria, or stavesacre, along with a num- ber of other bases which may be products of its decom- position. Veratrum viride. Several species of the genus Vera- trum have been found to contain alkaloids which re- semble aconitine in their action upon the heart. The only preparations in use as cardiac depressants are de- rived from the rhizome and roots of the American or green hellebore, veratrum viride. After the adminis- tration of veratrum viride to man the first effect upon the circulatory system is a reduction of the force of the pulse; the rate is not at first influenced. A little later the pulse rate is much reduced; in exceptional cases it may fall to 35 or even 80 beats per minute, any alarming symptoms which may arise passing away when the ad- ministration of the drug is discontinued. The pulse may be moderately full, but it is soft and compressible. If any exertion be made at this stage the pulse becomes very rapid and may become almost imperceptible. The slowing is especially marked during sleep, the patients thus exhibiting an intensification of the ordinary physio- logical law in virtue of which the pulse falls during sleep. The reduction in pulse rate is often accompanied or followed by nausea and vomiting; there seems, how- ever, to be no connection between these, for if the drug is administered with care a very marked reduction of the pulse rate may occur without any nausea being produced. Decided muscular weakness accompanies the depression of the pulse. Profuse perspiration also occurs; this is frequently attributed to the low blood pressure, but as the drug stimulates the cutaneous glands of frogs it is not improbable that it has some direct action upon the terminations of the sweat glands. After toxic doses there are also a fall of temperature and convulsions as in aconite poisoning and a running, almost imperceptible pulse. Efforts have been made to analyze the action of the veratrum alkaloids by experiments upon animais, but these have not as yet been entirely satisfactory. This result is due largely to the confusion which has prevailed as to the chemistry of these bodies, so that it is not always certain with what substances the various in- vestigators have worked. According to Wright and Luff the following alkaloids occur in veratrum viride: jervine, pseudojervine, cevadine, very little rubijervine 689 Cardiac Depressants, Cardiac Depressants, and traces of veratrine and veratralbine. The alkaloid called by Wright and Luff “cevadine” has the empirical formula C32:H4,NOx,; this is usually called “ veratrine” or the “crystalized veratrine of Merck,” and will be so designated here. There are three modifications of this veratrine, one crystalline and two amorphous; they all have the same physiological action. The alkaloid called by Wright and Luff “veratrine” has the formula C3:HssNO;1; its physiological action is not well known. Bullock discovered an alkaloid in veratrum viride which he named veratroidine; this seems to have been a mix- ture of rubijervine and an almost inert resin. Wood studied the physiological action of jervine and the so- called veratroidine. The alkaloids the physiological ac- tion of which have been most studied in Europe have been derived from veratrum sabadilla (Asagroea offici- nalis) and VY. album. The seeds of the former contain veratrine (Cs2H4.NOy,), the veratrine of Wright (C37Hs5s- NO,,;), and cevadine. A mixture of these alkaloids con- stitutes the Veratrina of the United States Pharma- copeia. Of these alkaloids only veratrine has been carefully studied, but it is not certain that the earlier in- vestigators worked with pure preparations. Veratrum album contains protoveratrine, jervine, pseudojervine, rubijervine, protoveratridine, and others; of these the physiological action of protoveratrine is best known. Thus the alkaloids of veratrum viride the physiological action of which is known are jervine, veratrine, and rubi- jervine. The effects produced by preparations of the entire drug are doubtless due largely to these three bodies, and a brief résumé of their action will be given. The principal investigation of the physiological action of jervine has been made by Wood (Amer. Jour, of the Med. Sciences, 1870, and Philadelphia Medical Times, iv., 1874), and the following account is taken from his papers. After the administration of jervine to an animal the pulse is generally, if not invariably, lessened in frequency, provided the animal is quiet. When there are convul- sions or even marked tremors the pulse becomes very rapid. The arterial pressure is greatly lowered, falling progressively from the beginning to the end of the ex- periment. The force of the individual beats appears not to be much altered at first. According to Wood these effects are not due to a stimulation of the cardio-inhibi- tory nerves, for they occur after section of these nerves. Stimulation of the peripheral ends of the vagiin animals under the influence of jervine caused the usual cardiac results. The alkaloid lessens the arterial pressure after division of the spinal cord—/7.e., after vaso-motor paraly- sis; it also paralyzes the heart of the frog or turtle when placed directly upon it. From these experiments Wood concludes that jervine lowers the force and frequency of the cardiac beats by a direct action upon the cardiac muscle or its contained ganglia. Apparently, however, Wood did not exclude the possibility of the slow heart being due to a stimulation of the vagus endings. Stimu- lation of sensory nerves or asphyxia caused little or no rise of arterial pressure, indicating a paralysis of the vaso- motor centre. Wood also studied the action of an alkaloid which he called veratroidine; this, as has been already noted, seems to be a mixture of rubijervine and a resin. This substance caused at first a slowing of the heart and a fall of arterial pressure. After a time, the pulse still re- maining very slow, the individual beats became unusu- ally powerful and the blood pressure became normal; then suddenly the pulse rate became very rapid, the in- dividual heart beats losing much of their extraordinary vigor, but the arterial pressure rising nearly fifty per cent. beyond its original position. If the alkaloid was thrown directly into a vein there was a very rapid fall, and then a remarkable rise of blood pressure; the latter is due to asphxyia and did not occur if artificial respira- tion was maintained. The slowing of the heart was due to stimulation of the cardio-inhibitory centres in the medulla; it did not occur if the vagi had been divided. If, moreover, marked slowing had occurred with intact vagi, section of these nerves was followed by a great 690 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. acceleration. The slowing was especially marked when the spinal cord had been cut so as to paralyze the ac- celerators; under these circumstances Wood saw gr. 35 of the alkaloid completely stop the heart, which how- ever commenced to beat again when the vagi were di- vided. After large doses the slow pulse was replaced by a very rapid one; that this was due, at least in part, to paralysis of the vagus termination was shown by the fact that stimulation of the vagus now had no effect upon the heart. Enormous doses thrown directly into the circulation killed the cardiac muscle directly. Ver- atroidine (rubijervine) had little or no effect upon the vaso-motor system. Asphyxia or stimulation of a sensory nerve caused a great rise of arterial pressure just as in normal animals. The action of veratrine upon the mammalian heart resembles in general that of aconitine, except that the stimulation of the cardiac muscle is not so marked. Bezold and Hirt (“ Untersuchungen aus dem physiolog. Laboratorium in Wiirzburg,” 1867, p. 95) describe the effect upon the circulation in mammals as follows: The first effect of a small dose is a slight acceleration of the heart, probably due to direct stimulation to the cardiac muscle; then comesa slowing of the heart. With a large dose the latter is the first effect; the pulse rate may be reduced to one-half or one-third the previous rate. Sec- tion of the vagi now is followed by an acceleration of the heart; this shows that the medullary centres of the cardio-inhibitory nerves are stimulated just as in aconite poisoning. At the same time there is an increase in the irritability of the vagus endings in the heart, for electric stimulation of the peripheral end of this nerve, which in the unpoisoned animal had no effect, produces a marked slowing after the administration of the drug. If the vagi be divided before the administration of the alkaloid, then this causes an acceleration of the heart, showing that the cardiac muscle is affected directly. This ac- celeration is followed by a slowing of the heart; this seems to be due toadirect poisoning of the heart muscle. With larger doses the heart is slowed still more, and now the strongest stimulation of the vagi has no effect upon the heart, showing that the vagus endings are paralyzed. These facts indicate that large doses reduce the irritabil- ity of the cardiac muscle and paralyze the terminations of the vagi, whereas small doses increase the irritability of both. After a very large amount of veratrine the heart be- comes irregular; unlike the heart in aconitine poisoning, however, it remains slow. The irregularity consists chiefly in the ventricle assuming a rhythm slower than that of the auricle; the ventricular beats then become weak and of a peristaltic character. Little blood is ex- pelled, and the ventricle becomes widely distended and finally stops in diastole; even electrical stimulation does not cause a contraction—indicating a profound poison- ing of the cardiac muscle. Small amounts of veratrine stimulate the vaso-motor centre; this and the slight stimulation of the cardiac muscle cause a rise of blood pressure. After larger amounts the vaso-motor centre is depressed; this in- creases the fall of blood pressure caused by the slow heart. Bezold and Hirt ascribed the fall of pressure in part to a stimulation of the depressor nerve, but later in- vestigators have failed to confirm this view. Lissauer (Archiv fir experiment. Path. und Pharmakol., xxiii., p. 36, 1887) -has obtained results slightly different from those of Bezold and Hirt. Thus, he thinks the chief action of veratrine is upon the vaso-motor system and that the heart is not as much depressed as was thought to be the case by Bezold and Hirt. Lissauer found no paralysis of the vagus endings. Hedbom (Skand. Archiv fiir Physiologie, viii., p. 197, 1898) has recently contributed a very interesting article on the action of veratrine upon the isolated mammalian heart. The heart (of the rabbit) was kept alive by the circulation of a mixture of blood and normal saline solu- - tion through the coronary arteries—7.é., by a modification of Newell Martin’s method. The contractions were j , 2 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES, C2Ta1a¢ Depressants. Cardiac Depressants, recorded by a thread attached to the ventricle and mov- ing a small lever. When a very small amount of vera- trine was mixed with the circulating blood there was first a sudden and very considerable (up to forty per cent.) increase in the amplitude of the contractions. This increase in the amplitude was due to a more complete systole, z.e., to a greater shortening of the muscle fibres. Soon the relaxation became less complete and so the amplitude decreased again. There was usually a slight acceleration of the heart (as described by Bezold and Hirt); this was followed by a marked slowing. During these slow, large heart beats the individual contractions were much prolonged—up to three and a half seconds. As is well known, one of the most characteristic of the physiological actions of veratrine is the peculiar effect it exerts on ordinary striated muscle; the contraction is in- creased and enormously prolonged. Bezold and Hirt, Bohm, and others have shown that the ventricle of the frog’s heart is affected in a way similar to that of the skeletal muscle. The experiments of Hedbom show that veratrine has a similar action upon the mammalian heart. The slight acceleration of the heart seen immediately after the injection of the drug seems to be due to a direct stimulation of the cardiac muscle; the more marked slowing which follows is probably due to a stimulation of the vagus terminations in the heart, as it is often re- moved by the administration of atropine. A secondary acceleration follows this slowing of the heart. This ap- pears to be due in part toa paralysis of the vagus termina- tions, in part to a stimulation of the cardiac muscle. This secondary acceleration is often accompanied or pre- ceded by marked irregularities, resembling those seen in digitalis poisoning. This irregularity is marked by the formation of groups and by the appearance of “ missed ” beats—7.e. strong contractions are followed by very weak, almost imperceptible ones. Finally, the heart muscle is paralyzed. Thus the action of three of the alkaloids of veratrum» viride upon the heart is tolerably well known; that of the others is very imperfectly known, but they seem to resemble those already described. No complete experi- ments seem to have been made with any of the ordinary preparations of veratrum viride in which all of the alka- loids are present, and it is not altogether easy to forma clear idea of the details of the action of such preparation from what is known concerning these three alkaloids. While chemical analyses show the proportion in which the various alkaloids occur in veratrum viride, we have few dataas to the comparative toxicity of the individual alkaloids. It seems, however, that veratrine is more powerful than most of the others, and since, according to Wright and Luff, it is the most abundant alkaloid in veratrum viride, it probably plays a much more impor- tant part in the action of the preparations of the crude drug than has been generally recognized. Rubijervine is also very poisonous, but it occurs in small quantities. From the various experiments described above, assum- ing that all are trustworthy, we may perhaps draw the following conclusions as to the action of veratrum viride upon the circulation: The slowing and weakening of the heart are due to the stimulation of the medullary centres of the cardio-inhibitory nerves by the veratrine and rubi- jervine (veratroidine). This slowing may be increased by the stimulation of the vagus terminations by the action of the veratrine. The slowing may be due in part to the direct action upon the cardiac muscle by the jervine, but this effect is doubtless antagonized to some extent by the stimulating action of the veratrine described by Hedbom. In therapeutics this slowing of the heart is the only effect desired, and it will be seen that it is produced to a large extent in the same way as when aconite is used—/?.e., by a stimulation of the vagus centre in the medulla. With veratrum viride there is another action, however, which is scarcely shown at all by aconite, viz., a stimulation of the vagus terminations in the heart, and it is possible that veratrum viride may thus cause slowing in some cases in which aconite would fail. The rapid pulse after large doses of the drug is due to a paralysis of the vagus terminations by veratrine and rubijervine and perhaps to some stimulation of the cardiac muscle. At the same time jervine and larger amounts of veratrine weaken the heart by a direct action upon the cardiac muscle. Vera- trum viride in large amounts does not tend to produce as rapid a pulse as does aconite, probably partly because all the alkaloids have a less stimulating action on the cardiac muscle and partly on account of the peculiar action of veratrine upon all kinds of striped muscle. The fall of blood pressure caused by veratrum viride is due largely to the slowing of the heart; at the same time the vaso-motor centre is depressed by the jervine and when larger amounts are given, by the veratrine. The physiological action of protoveratrine, the chief alkaloid of veratrum album, has been studied by Eden (Archiv fiir exper. Path. und Pharmakol., xxix., p. 440, 1892). As faras its action upon the circulation is con- cerned this alkaloid does not differ very much from veratrine. Tartar Emetic.—Tartar emetic is classed with the car- diac depressants for clinical and not for pharmacological reasons. Although it depresses the circulation to a marked degree, it has no such special action upon the heart as have aconite and veratrum viride; in fact its action does not differ greatly from that of several other drugs which, since they have never been used clinically for this purpose, are never thought of as cardiac de- pressants. The action of tartar emetic upon the pulse in small doses is closely connected with, and to a considerable extent dependent upon, its action as an emetic, for ordi- narily it is absorbed very slowly and in very small amounts. The effect upon the circulation of man is de- scribed by Ackermann (Virchow’s Archiv, xxv., p. 581, 1862) as follows: After a small dose the pulse becomes accelerated as feelings of nausea arise and reaches its maximum rate just before the act of vomiting. Thus in one case the normal pulse rate was 71 per minute; during the period of nausea it rose to 110. The strength of the pulse decreases with the increase in rate, and vice versa. It is not necessary for vomiting to occur; the mere sensation of nausea is sufficient to cause an ac- celeration of the heart. Any drug (such as apomor- phine) or any condition (as sea-sickness, swinging, etc.) which causes feelings of nausea is accompanied by a similar acceleration of the pulse. This acceleration is sometimes attributed to a reflex stimulation of the ac- celerator nerves, but it is more probable that it is due to a reflex diminution of the tonus of the cardio-inhibitory nerves. Accompanying this change in the pulse rate and probably dependent upon it there is a fall of tem- perature of the extremities and other symptoms of mild collapse. Thus Ackermann found the temperature of the hands to fall .2 to 3.5° C. during the period of nausea; the temperature under the tongue did not vary. After large doses the pulse becomes very feeble, then slow, in- termittent, and irregular and the other symptoms of col- lapse are very marked. The depression of the central nervous system and of the respiration is doubtless due in part to the circulatory disturbances. These more pro- nounced effects upon the circulation are probably due in part toa direct action of the poison upon the heart. That antimony does exert a depressing action upon the heart is shown by experiments upon the lower animals; the action is most marked in the case of the frog’s heart. Soloweitschyk (Archiv fiir exper. Path. und Pharmakol., xii., p. 441, 1880) found that for some time after the ad- . ministration of antimony (in the form of the antimony- sodium tartrate) to a frog the heart continued to beat regularly; the contractions were at times unusually vig- orous and the rate was slightly increased. Then the con- tractions became irregular and peristaltic; arhythmia of auricle and ventricle soon developed, the latter beating but one-half, then one-third, one-fourth, etc., as rapidly as the former. Finally the ventricle stopped in diastole while the auricles continued to beat feebly. The cardiac muscle does not seem to be paralyzed, for a little helle- borein will cause it to commence beating again; only the : 691 Cardiac Stimulants, Cardiac Stimulants, power to contract rhythmically seems to be destroyed by the antimony. That this stoppage of the heart is not due to a stimulation of the vagi is shown by the fact that atropine has no influence upon it. It is difficult to state exactly the effects of antimony upon the mammalian heart, for in the experiments hither- to recorded the effects upon the heart were not differen- tiated from those upon the vaso-motor system. It is very probable, however, that after large amounts of antimony the mammalian heart muscle is influenced in a way very similar to that of the frog, but that this action is obscured by the vaso-motor changes. Injected into, a vein or an artery of an animal antimony causes an almost immediate acceleration of the pulse. At the same time the blood pressure falls; this fall of blood pressure is gradual but continuous until it reaches zero and the ani- mal dies. When the fall of blood pressure has become very marked (in many cases when it has fallen to about one-half or one-third its previous height) the heart be- comes slow and irregular. The diastolic pauses are greatly prolonged, but the chan ges in the blood pressure followi ing each contraction are very great, indicating that the heart beat is fairly strong and that the vessel “walls are much relaxed. This fall of arterial pressure cannot be ascribed to the weakening of the heart, for it precedes this, and there is no constant relation between the con- dition of the heart and the height of the blood press- ure. The cause of the fall of blood pressure seems to be a paralysis of the peripheral vaso-motor system; the blood-vessels, especially those of the splanchnic area, are dilated and the most powerful stimulation of the medulla oblongatais powerless to contract them. It isnot known whether the vaso-motor nerves or the muscle of the vessel walls or both are poisoned; the fact, however, that other unstriped muscle (that of the intestines for example) is not paralyzed points to the nerves or their ganglia being the structures acted upon. It is not impossible that the changes in the heart are in reality due to the great fall of arterial pressure, but the fact that antimony has such a poisonous action upon the frog’s heart makes it prob- able that the mammalian heart is similarly affected. The heart finally stops in diastole; just before the final stand- still there is frequently a very brief period during which the heart beats with great rapidity, but the contractions are exceedingly weak and the blood pressure remains very low. The cardiac nerves do not seem to be involved in the later stages of the poisoning. Some have stated that the vagus terminations are paralyzed, but this does not seem to be the case. Immediately after death the heart is found to be unirritable to electrical stimulation. There are a number of other drugs which affect the circulation in ways similar to the above and which might be classified with the cardiac depressants; that they are not so classified is due to the fact that they have never been used to any great extent for their action upon the heart. Among these substances may be mentioned salicylic and carbolic acids, potassium salts, double salts of copper, zinc and some other heavy metals, chloral, saponin, apomorphine, emetine, muscarin, cholin, pilo- carpine, hydrocyanic acid, and the various mineral and organic acids. With some of these drugs it is largely a matter of dosage; small amounts may stimulate the heart while larger amounts depress it. There are also drugs which may at times relieve, in one way or another, the heart and so act as cardiac seda- tives. Thus atropine seems to reduce the sensibility of the nervous structures of the heart to increased pressure, and Brunton has found it useful in some cases of palpita- tion with high blood pressure and in persons suffering from the effects of cardiac strain followi ing violent mus- cular exertion. Digitalis was at one time called a car- diac sedative from its power to cause a rapid, irregular, irritable heart to beat slowly and regularly; in such cases the action is exerted largely through the inhibitory nerves and so has a certain resemblance to the action of aconite and veratrum viride, although there are other ae for placing these drugs in entirely different classes 692 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Some drugs may have the effect of cardiac sedatives by reducing irritation which has caused, reflexly, palpi- tation of the heart; thus hydrocyanic acid will sometimes relieve the palpitation caused by indigestion. In some cases local irritation will prevent the most powerful of the cardiac depressants from exerting their normal ac- tion. An interesting case of this kind is described by Percy (Trans. Amer. Med. Ass’n, 18638, p. 268). Large repeated doses of veratrum viride had no effect upon the pulse of a patient until two large and very active ascarides were removed from the stomach by vomiting; after this had occurred there was an immediate and marked reduction in the pulse. There are certain mechanical means which produce effects analogous to those caused by the cardiac depressants. Thus pressure over the heart—such as that caused by a plaster—removal of blood by venesection, and the application of cold to the cardiac region all re- duce the force and frequency of the heart beat and may be used instead of drugs. It is difficult to form an opinion as to the extent to which the three chief cardiac depressants—aconite, vera- trum viride, and tartar emetic—are employed at present, the practice of physicians varying so much. The gen- eral indication for their use has been said to be “increased arterial excitement, sthenic fevers, and severe local in- flammations.” In the first condition they are used ae ply to reduce the force and frequency of the pulse; sthenic fevers they are used not only to lessen the ieee of the heart but to obtain a relaxation of the peripheral vessels, while in local inflammations it is desired to divert, by their use, the blood into other channels. Pneumonia was formerly thought to be pre-eminently a disease in which these drugs were to be used and all three have been employed very extensively init. At present they are used to a much more limited extent; this is especially true of tartar emetic, and although many use aconite and veratrum viride, some have discarded all three and use the lancet when they think it desirable to depress the circulation. The reader is referred to the articles in this HANDBOOK on the various disturbances of the circulation for a discussion of the use of these remedies, but a few of the cases in which they are employed will be simply mentioned here. Aconite seems to give the best results in inflammations of limited extent, especially in tonsillitis, quinsy, and acute sore throat. Much of the relief in these cases seems to be due to the perspiration which follows the depression of the circulation. By diverting the blood away from the inflamed tissues these become less painful and the swelling subsides. Aconite is often serviceable in severe colds, in otitis, and in certain forms of asthma. It is sometimes used in nervous palpitation of the heart and in that occurring in excessive hypertrophy of the heart— although here it may become a very dangerous remedy. Occasionally it will relieve restlessness and give the pa- tient refreshing sleep. Veratrum viride seems to be used as a cardiac depress- ant to a more limited degree than aconite; it is probably used more extensively in pneumonia and puerperal fever than in the numerous other conditions for which it has been recommended. Tartar emetic is probably used still less for its action upon the circulation, although it is praised very highly in typhus and other fevers when there is much excite- ment .and wild delirium. It is used much more exten- sively as a diaphoretic, although its action as such may depend to some extent upon its power to depress the circulation. . : II. Carprac STIMULANTS. There are a great many drugs which can increase, in one way or another, or under certain circumstances, the force of the circulation; to a few of these which are used largely by physicians for this purpose the name “ cardiac stimulants” is applied. Aside from their action on the circulation, these drugs have little in common in either their chemical or their physiological properties. Their REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Cardiac Stimulants, Cardiac Stimulants, action upon the circulation is, moreover, brought about in the most diverse ways, and is often determined to a consid- erable extent by the previous condition of the circulation. Some act chiefly upon the blood-vessels, others upon the heart; some act reflexly, others directly; while some may cause one kind of change reflexly and just the op- posite when absorbed; some slow, others accelerate, the heart. The action of some is very rapid while that of others is slowly developed and long continued. The last- named difference has served as a basis for the only classi- fication of these drugs it seems possible to make. Those which act rapidly are called “cardiac stimulants proper ” or simply “cardiac stimulants,” those with a slower ac- tion “cardiac tonics.” Cardiac stimulants, used in the narrower sense, bring about their effects largely reflexly and are used to pre- vent or counteract sudden failure of the heart’s action. They are used especially in fainting fits or syncope due to sudden emotion, physical injury, poisoning by car- diac depressants, or when the heart fails suddenly in fevers, after snake-bites, etc. The action of most of them is primarily upon the blood-vessels, and the heart is usually influenced only secondarily. They may be administered by inhalation (as is the case with ammonia in smelling salts), by the stomach or subcutaneously or intravenously. When applied to a mucous membrane they exert their influence largely through their local irritating action; some have little action after absorption while others (such as alcohol and ether) are essentially cardiac depressants when they once get into the circula- tion. These drugsare seldom used when there are organic changes in the heart. The most important members of this group are alcohol and the various liquids containing it in concentrated form, ether and chloroform—these three only when brought into contact with a mucous membrane or in- jected subcutaneously—the various preparations of am- monia, camphor, and the volatile oils. One of the most powerful of all cardiac stimulants is heat applied to the cardiac region. In addition to the above there are many drugs which, under certain cir- cumstances, may act as cardiac stimulants but which are not ordinarily included under that heading. Axconont.—Dr. J. J. Abel, who has given considerable attention to the subject of alcohol, has prepared the fol- lowing summary of its action upon the circulation. (For amore complete account see Dr. Abel’s paper in the re- port of the “ Committee of Fifty.”) It has long been a matter of discussion how best to define the action of ethyl alcohol and of alcoholic fluids on the circulatory apparatus. The term “circulatory stimulant,” as applied to alcoholics of all kinds, is firmly fixed in medical literature, but it has become impossible, in view of modern analyses, to retain this term in its original significance. The appearances of so-called stimulation are manifest especially in those individuals who are unaccustomed to the use of alcohol, and who possess an excitable vascular apparatus. In such the eyes become more brilliant, a sensation of warmth is ex- perienced in the stomach and on the surface of the body, the sweat glands, the salivary and gastric glands are stimulated, the pulse is fuller and faster, gestures and muscular movements in general are more frequent and more pronounced, and the respiration responds by an in- crease in rate and depth. The environment often sup- plements the action of the wine or other beverage in its emotional or intellectual effect. In view of these phenomena it is not strange that mankind speaks of al- cohol as a cerebral, circulatory, or respiratory stimulant. When it comes to the action of alcoholics on the cir- culatory apparatus, numerous difficulties are encountered ; secondary or reflex must be separated from primary ac- tions. But nowhere has modern analysis given us a clearer idea of the true action of a substance than in that of alcohol on the various parts of the circulatory ap- paratus. What is to follow holds, strictly speaking, for pure ethyl alcohol only. Yet it will be found to hold also for wines, spirits, and other forms of alcoholics which mankind has accepted after long and frequent empirical trials. It must be borne in mind that esters, aldehydes, the small quantities of higher alcohols, the salts, etc., in short the sum of the by-products of alco- holic fermentation, are quantitatively insignificant in comparison with the ethyl alcohol contained in all alco- holics. This becomes strikingly evident when they are studied in the light of toxicology. Thus, 1 litre of brandy will kill 64.9 kgm. of living animals (dogs, rab- bits, etc.), while the ethyl alcohol alone of this litre of brandy will kill 64.38 kgm. It is not denied that these by-products have a very important action on the sense of taste and that of smell, and on the functions of the digestive tract, nor that they noticeably enlarge the effects about to be described. It is especially the esters of wines and spirits which are to be thought of in this con- nection as slightly increasing the action of the ethyl alcohol, as their action is similar to that of alcohol, though more intense, quantity for quantity. When we inquire into the direct action of alcohol on each of the several parts of the vascular apparatus taken by itself, we reach the following conclusions. I. Action of Alcohol on the Isolated Heart.—Al\cohol in small and moderate quantities, that is, in such amounts as are to be fonnd in the blood in any condition far short of intoxication, does not have a direct stimulating action upon the isolated heart of either warm- or cold-blooded animals; indeed, moderate quantities show no appreciable action either in the way of stimulation or depression. The experiments of Martin and Stevens, Hemmeter, Ringer and Sainsbury, Dreser, Diaballa, Bock and others, furnish incontrovertible proof of this statement. But such a statement does not refer to the long-continued daily administration of small and moderate quantities of alcohol, but solely to its administration during brief periods, as in physiological experiments. In very large doses, such, for example, as result in helpless and perhaps fatal intoxication, alcohol is seen to be a direct and powerful depressant of the heart, weak- ening first the auricular, later the ventricular systole, causing more or less distention of both cavities, marked slowing of its movements and great diminution of its output of blood. As we shall see later, these positive statements do not stand in contradiction of the fact that alcohol is of frequent and beneficial use in conditions of great depression of the heart or central nervous system. In experiments like those from which the above conclu- sions were deduced, the heart was severed from all vital connection with the rest of the body. Il. Direct Action on the Walls of the Arteries and Veins, that ts, the Blood- Vessels Removed from all Central Nervous Control.—Small and moderate quantities of alcohol have no direct action on the walls of the blood-vessels. Very large amounts no doubt have a direct dilating action on the vessels, like that shown for the heart itself. The flushing of the face and other parts of the body so fre- quently observed after moderate quantities of alcohol is brought about by an action on the central nervous mechanism which controls the calibre of the vessels. Ill. Influence on the Arterial Blood Pressure.—Here we are dealing with a resultant effect of the work of the heart, and of the peripheral resistance offered by the smallest blood-vessels. These interdependent variables are affected through controlling nerves, and it is evident that here is an opportunity for indirect influences of various kinds. It must be admitted that blood-pressure measurements are of minor importance to the clinician. It is well known that minor fluctuations in the arterial pressure are of frequent occurrence, and Hensen even affirms that daily changes of 40 to 60 mm. Hg are not uncommon in individuals lying in bed. Arterial pressure, as usually measured, gives us only the lateral pressure on the walls of the larger arteries, and without additional data it gives us no information on that important question, the intensity of the blood flow—in other words, the amount of blood which passes in the unit of time through a given capillary area. Whether an organ will receive its re- 693 Cardiac Stimulants, Cardiac Stimulants, quired amount of oxygen and other necessary material must all depend on this. Now the state of constriction of the peripheral arterioles is a factor of the greatest im- portance in determining the value of this resultant as well as of the arterial pressure. As Krehl, Hensen, and others have pointed out, even during periods of little or no variation in the aortic pressure, considerable varia- tions are possible in the unit quantity of blood passing through the aorta. In other words, variation in the peripheral resistance may be offset in such a way by re- sponsive variations in the action of the heart that a change occurs, either in the way of an increase or de- crease in the amount of blood passing through the organs of the body, although aortic pressure remains practically unchanged. As a rule, however, an increase in arterial pressure means an increase in the intensity of the periph- eral circulation. Being an important item in the study of the hemodynamics, blood-pressure determinations can- not be neglected; yet it is necessary to point out, as Hensen has well said, that what we most need to know is not the arterial blood pressure, but rather the relation of the quantitative blood flow in any given organ to the actual needs of that organ, a relation which at present it is im- possible to determine. In regard to the action of alcohol on the arterial press- ure, we may say that, given in moderate quantities and in such a dilution as to avoid the consequences of local irritation, it has no appreciable effect on it. When so large a quantity is given that a change in the pressure be- comes apparent, it is always in the direction of a fall and not of arise. In the early stages of its action it usually causes some degree of flushing of the skin and brain, and later, when very large quantities have been taken, dilata- tion of the abdominal vessels occurs. A marked fall of blood pressure due to such large quantities is a toxic phenomenon, and is never met with under ordinary cir- cumstances. It is due to a sedative or depressant action of the alcohol on the vaso-motor centres, and also in part to its action in weakening the heart. IV. Action of Alcohol on the Pulse Rate.—When alcohol or beverages containing alcohol are administered to healthy persons in small doses, or even in such doses as will produce transient psychical changes, no alteration of the pulse rate is usually observed, provided that local irritation in the mouth and stomach is avoided, and the indirect effects of the mental action of the alcohol, such as bodily movements, are not allowed to influence the experiment. It is not improbable that in some excitable individuals the cerebral effects of the alcohol and the cir- cumstances of its administration may combine to induce such mental effects that slight changes in the pulse rate occur. As a rule, when the quantity of alcohol administered is not too small, the character of the pulse wave undergoes a slight change, the pulse becomes fuller and softer in con- sequence of a dilatation of superficial arteries. The heart is not weakened at this time, and the fuller pulse may give a false impression and lead to the belief that the arterial tension has been raised. The pulse tracings of Marvaud, Parkes, von Jaksch, Jaquet, and others, show that moderate quantities of alcohol influence the form of the pulse wave in like manner with chloral and other hypnotics, though less markedly from a quantitative point of view. The slight dilatation of the superficial arteries is due to the sedative action of the alcohol on the vaso-constrictor centre of the medulla, and is not sufficient to lower the arterial tension as measured in the carotid. By virtue of its local action on mucous membranes, and also by virtue of its cerebral effects, alcohol is capable of influencing the several parts of the vascular apparatus in a number of ways often directly opposed to those mentioned above. Such indirect effects are com- mon to its pharmacological congeners, and are familiar in the use of alcohol in daily life and in medical practice. Of these none is more often observed than a quickening of the pulse rate. Such indirect effects must not be allowed to obscure its true inherent action, which is al- 694 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ways depressant in kind. When once in the blood and tissues, it must be classed with the anesthetics and narcotics. It is not to be inferred that the above statements for- bid a reasonable and prudent use of alcohol in thera- peutics. The records of clinical medicine show that alcohol, by virtue of its numerous indirect as well as direct influences, often serves the purpose of a “circu- latory stimulant.” In conditions of shock the weak pulse may become fuller and stronger, the feeble heart may beat more vigorously. Again, a quick pulse may become slower as the rapidly beating, fluttering heart is induced to slow down to a regular rhythm. Otherexamples need not be cited. The day is happily past when the thera- peutist plied his patient with a number of bottles of wine a day in the belief that he could stimulate the heart, lower the temperature, supply nutriment, and effect other good ends, without detriment of any kind, by giv- ing these large quantities. Certainly its administration in excessive doses can only do harm. Though the pharmacologist cannot admit that this agent is capable of stimulating the isolated mammalian heart, it would be rash to assert that it cannot serve as a cardiac stimulant in the human system. Gutnikow, who accepts it as a proved fact that alcohol can only lower the arterial pressure, when once it has reached the circulating blood, has made it the object of his researches to harmonize this with the equally well-known fact that it is often used in medical practice as an analeptic, as an agent that “strengthens and fortifies the heart.” Ac- cording to this author the sum total of the action of alcohol on the circulation is to the effect that, although there is a condition of lowered arterial tension, yet the mutual relations of the pressures in the cavities of the heart and in the arteries and veins are such that the heart works as tf tt were strengthened. It now has an easier task to keep all the minute arteries and veins and the capillaries well filled; under the new conditions its propelling power is not injured but rather improved. It may well be the case in certain clinical conditions, in the light of the remarks made in a previous paragraph on the relations existing between aortic pressure and the volume of the peripheral circulation, that alcohol will give cause for a better peripheral circulation, although the aortic pressure is slightly lowered. Whatever may be the future theories in regard to its clinical uses, the old position of alcohol as a blood-press- ure-raising agent and heart stimulant can no longer be defended, and it remains for the practitioner to use this agent with care and great discretion. Ammonia.—The preparations of ammonia which are used for their effect upon the circulation are solutions of the gas in water or in alcohol and the carbonate; the latter is a rather complex mixture of the carbonates and carbamates of ammonia, which give off ammonia on ex- posure and hence has an action similar to but less power- ful than that of the solutions of ammonia. Ammonia has a very powerful local action as well as an action upon the nerve centres when it reaches the cir- culation and it is important to distinguish between these. When ammonia reaches the circulation it is converted into urea'very rapidly; hence unless considerable quanti- ties are injected at once into the circulation no symptoms are produced. While ammonia is absorbed with con- siderable rapidity from the stomach, it is doubtful whether after the use of medicinal doses it reaches the circulation in sufficient concentration to have any appreciable ef- fect. Hence the effects of ammonia (and of ammonium carbonate) when given by the stomach are due largely, if not entirely, to the reflexes caused by its local action; the effects of the intravenous injection of considerable quantities will be discussed later. The effects of ammonia can be elicited by applying it to either the respiratory or the digestive tract or subcuta- neously, and consist of a powerful reflex stimulation of the vaso-motor and respiratory centres. The result is a rise of arterial pressure and an improvement in the pulse; ‘ the latter is probably dependent upon the rise of blood 0 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES, C2rdiac Stimulants, Cardiac Stimulants, pressure, for the heart, so far as it is affected reflexly at all, seems to be slowed by a stimulation of the vagus centre. The rise of blood pressure will rouse the patient from a fainting spell, from a condition of sudden collapse, from failure of the circulation during anesthesia and from similar conditions. The effect is very transitory, but is often sufficient to carry a person through a dangerous period. Both the physiological action and practical ex- perience point to the conclusion that ammonia is of little service when the failure of the circulation is dependent upon some slow and persistent cause. If ammonia is applied to the nostrils for too long a period or in too concentrated a form it may produce inflammation of the respiratory passages; also when it is swallowed in large quantities some of the vapor may reach the re- Spiratory passages and cause death by cedema of the larynx. When ammonia or one of its neutral salts is injected directly into the circulation of a mammal the effects are those observed whenever a powerful stimulant to the medulla or spinal cord is injected—increase of respira- tion, convulsions, tetanus, and a rise of blood pressure. ‘These effects are probably due to the irritating action of the ammonia upon the nerve cells rather than to any specific stimulation of them, as is the case with such an alkaloid as strychnine for example. Very similar effects follow the subcutaneous application of ammonia or of its salts, although here the effect is complicated by changes brought about reflexly. The results are the same what- ever the salt used, provided the acid in combination has not, of itself, a poisonous action; this shows that, the results are due to the ammonium ion. A considerable amount of a salt of ammonia may be injected into the circulation of an animal without pro- ducing any toxic symptoms, provided the injection be made very slowly. Thus Marfori (Archiv fiir exp. Path. and Pharmakol., xxxiii., p. 71, 1893) showed that .03 gm. of ammonia (in the form of the carbonate) per kilogram could be injected per hour into a dog without causing ‘any symptoms. The explanation of this is that the am- monia is rapidly converted into urea. The effects of ammonia and its salts when injected rapidly into the circulation or subcutaneously into an animal have been investigated by Blake (Hdin. Med. and Surg. Jour., lvi., p. 1, 1841), Lange (Archiv fiir exp. Path. und Pharmakol., ii., p. 875, 1874), Funke and Deahna (Archiv fiir die ges. Physiol., ix., p. 416, 1874), and For- manek (Archives internat. de Pharmacodynamie et de Therapie, vii., p. 229, 1900). The first effect is usually a ‘slowing of the heart and a slight fall of blood pressure; then there is a marked rise of blood pressure, the heart ‘sometimes remaining slowed, sometimes being acceler- ated. Theslowing of the heart and the first fall of blood pressure are due almost entirely to a stimulation of the ‘centre of the cardio-inhibitory nerves, for they usually ‘disappear immediately upon section of the vagi. There ‘may sometimes be a slight, unimportant slowing of the heart after section of the vagi; this is probably due to a ‘slight stimulation of the vagus endings in the heart, for these are stimulated by a great many of the drugs which ‘stimulate the medullary centres of the vagus. Ifa very large amount of ammonia is injected into a vein the heart may be poisoned directly and may either beat very ‘slowly or be arrested at once in diastole. The rise of blood pressure has been attributed by some to a stimulation of the heart, by others to a stimulation of the vaso-motor system; it is due to both of these, but probably more to the latter than to the former. The -action of the salts of ammonia when directly applied to the frog’s heart has been studied by Ringer and Sains- bury. These results are of especial value because no ‘similar experiments have been made upon the mam- ‘malian heart. Briefly stated, Ringer finds that am- monium salts added to the nutrient fluid circulating through the isolated frog’s heart increase, in small doses, the strength of the-ventricular contractions, but that larger doses destroy muscular contractility; spontane- yous action, however, continued until contractility was lost; in the end stage there was no response even when the ventricle was strongly stimulated electrically. Ringer also finds that ammonia lessens dilatation of the ventricle and arrests it insystole. If the heart has been weakened by chloroform or other anesthetics, the beat is strength- ened by ammonia, and a heart stopped in diastole by chloroform passes into the condition of systole under the influence of ammonia. Since these experiments were made upon the ventricle of the frog’s heart we are justified in concluding that ammonia stimulates the car- diac muscle directly. It isnot known to what extent ammonia has a similar action upon the mammalian heart. An acceleration and strengthening of the heart beat some- times follows its injection, but this stimulation is usually of short duration and does not always occur. Some think that the improvement in the heart beat is to be attributed to the rise of blood pressure rather than to a direct effect upon the heart, while Formanek thinks it is due in part to a stimulation of the accelerator nerves. The great rise of blood pressure following the injection of ammonia is usually attributed to a stimulation of the vaso-motor centre, and this view is made very probable by the fact that the other medullary centres are so powerfully stimulated by this substance. Funke and Deahna found that in frogs section of the cord or of the sciatic plexus greatly diminished or abolished altogether the constriction of the blood-vessels following the sub- cutaneous injection of ammonia. On the other hand, there is considerable experimental evidence that the peripheral vaso-motor system (the nerves or the muscles of the vessels) is stimulated directly. Thus Lange ob- tained a marked rise of pressure after division of the cord, 7.e., after the vaso-motor centre had been separated from the arterioles. Beyer (Medical News, 1886) trans- fused the vessels of terrapins (from which the heart had been removed) with Ringer’s solution to which salts of ammonia had been added. There was first an increased then a diminished outflow from the veins, 7.e., a dilata- tion followed by a constriction of the blood-vessels. We are probably justified in concluding that the rise of blood pressure caused by ammonia is due partly to a stimula- tion of the vaso-motor centre and partly to a direct ac- tion upon the arteries; it is very probable that direct stimulation of the heart also is a factor, especially if this organ has been previously weakened by anesthetics, etc. Binz (Centralbl. fiir klin. Med., ix., p. 26, 1888) found that if the arterial pressure of an animal was made very low by the administration of chloral hydrate, am- monia would cause it to rise; the improvement was, however, temporary and when the ammonia was pushed convulsions followed. Intravenous and hypodermic injections of ammonia are sometimes made in cases of sudden and dangerous col- lapse, as in failure of the heart during anesthesia, in cholera, after injuries, etc. It has been used extensively in cases of poisoning from snake bite but the improve- ment in these cases seems to be temporary. When ammonia is administered by the mouth or by the respi- ratory tract the only effect upon the circulation is the reflex stimulation of the vaso-motor centre; by its intra- venous use the peripheral vaso-motor system as well as the medullary centre is stimulated and there is further probably some direct action upon the heart. When am- monia is given intravenously in very large amounts there is danger of causing convulsions; animals, however, usually recover quickly from such convulsions. Camphor.—Camphor has long been used, especially in Germany, as a cardiac stimulant in cases of collapse and cardiac weakness from fevers and other causes; the pulse becomes fuller and stronger under its influence. State- ments as to the action of camphor upon the heart are in- complete and in some cases contradictory ; moreover, its cardiac action is undoubtedly much obscured by its ac- tion on the central nervous system, the respiration, and the vaso-motor centre. The beneficial effects in collapse, etc., are probably due quite as much to these effects as to the effects upon the heart. Camphor has, moreover, a well-marked local action and it is not easy to distin- 695 Cardiac Stimulants, Cardiac Stimulants, guish between the effects produced reflexly and those produced after its absorption. Some of the rather fragmentary statements as to the action of camphor will be given. Lewin (Archiv fir exper. Path. und Pharmakol., xxvii., p. 229, 1890) found that camphor administered to rabbits in which the blood pressure was extremely low as a result of large doses of chloral hydrate caused a marked rise of pressure; fre- quently it was doubled. The rise of blood pressure was longer continued when the camphor was given by the stomach than when it was injected into a vein. Lewin argues that since the vaso-motor centre was paralyzed by the chloral the rise of blood pressure must have been due largely to a stimulation of the heart (for camphor has, so far as is known, no direct stimulating action upon the peripheral vessels). If the chloral anesthesia was not so very deep then the vaso-motor centre was stimulated, as was shown by the fact that it became sensi- tive to the effects of asphyxia. It is a significant fact, however, that Wiedemann (Archiv fiir exper. Path. und Pharmakol., vi., p. 228, 1876) failed to obtain any rise of blood pressure from the administration of camphor after section of the spinal cord—as would be expected if Lewin’s conclusions are correct. It is very probable that there was some source of error in the experiments of one or the other investi- gator. Their results could, however, be brought into ac- cord if we suppose the medullary centres of the acceler- ator nerves to be stimulated by the camphor. There is, however, no experimental basis for the latter sup- position. Small doses (five to ten grains) administered to a healthy man usually cause an acceleration of the pulse, although sometimes they have little effect or may even cause slowing. Larger doses (twenty grains or more) slow and weaken the pulse; after toxic doses the pulse may be accelerated again. When from any of a number of causes the pulse is very weak or almost imperceptible, camphor will make it fuller and stronger. Binz and Baum found that in animals in which fever had been induced by the injection of putrid matter, camphor increased the strength of the heart beat and caused it to continue longer after death than in the case of control animals. Heubner (Archiv fiir Heilkunde, xi., p. 3834, 1870) and Harnack and Witkowski (Archiv fiir exper. Path. und Pharmakol., v., p. 427, 1876) state that camphor causes the frog’s heart to beat more slowly but more powerfully ; this is due, according to these authors, to a direct action upon the heart, for the latter can be made to beat again after it has been brought to a standstill by muscarine, and, on the other hand, neither muscarine nor stimulation of the vagus can stop the heart poisoned with camphor. Lewin (doc. cit.) found the frog’s heart to be slowed by a prolongation of the systole; the diastole was less complete and so the output was diminished. Thus the effect of camphor upon the frog’s heart is similar in some respects to that of digitaline. The blood-pressure in mammals is usually considerably increased by camphor; this seems to be due in part to an action upon the heart, in part to a stimulation of the vaso-motor centre. Whether the latter is stimulated directly or reflexly isnot known. In some cases rhyth- mical variations of the blood pressure appear; these are especially marked if convulsions occur, but they are also seen when convulsions are prevented by curare (Wiede- mann, loc. cit.). It has been suggested that these rhyth- mical variations are due to a direct action upon the vaso- motor centre, just as the convulsions are due to a direct action upon the cerebral cortex; or the cerebral cortex may send rhythmical impulses to the vaso-motor centre independently of those causing the convulsions. Thus, as far as we are able to judge from the avail- able data, camphor has an action upon the circulation similar to that of ammonia, and it seems to be of use in similar conditions. Like that of ammonia the action of camphor is very transitory. Van der Helm (“ Versuche tiber einige arzneiliche Erregungsmittel,” Dissert., Bonn, 696 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. 1887, p. 28) says that the action of camphor upon the blood pressure, as well as upon the respiration, is longer continued thanis that of ammonia. Attention was called above to the fact that the effect of camphor is more last- ing when it is given by the stomach than when injected intravenously ; the explanation of this is probably that in the latter case the camphor is very rapidly destroyed in the organism. Moreover, when the drug is given by the stomach, the reflex as well as the direct effects of its ac- tion are obtained. The slight solubility of camphor in water and the consequent great irregularity of its rate of absorption from the digestive tract are two of the chief drawbacks to its employment in therapeutics. A num- ber of the other members of the camphor group have been studied, but as yet no good substitute for camphor has been discovered. Camphorol, amido-camphor, and camphoric acid resemble camphor in their physiological action but are less powerful. Musk has also been used as a cardiac stimulant in con- ditions similar to those for which camphor has been pre- scribed; it has been especially recommended in certain cases of advanced typhoid fever. Almost nothing is known as to its physiological action, but it seems to strengthen the heart beat; it has a more decided action upon the respiration. Most of the volatile oils when taken into the stomach act as mild cardiac stimulants. Their action is entirely a reflex one, for when injected into a vein they depress the vaso-motor centre and, in large doses, the heart. Cardiac Tonics.—Those drugs which are employed to. produce a more lasting effect upon the heart are called. cardiac tonics. They act chiefly upon the cardiac muscle; to a less extent upon the cardiac nerves and the vaso- motor apparatus. Their action is usually slow; fre- quently no change in the circulation can be made out for many hours, sometimes not for days, after their adminis- tration has been begun. It is chiefly in diseases of the heart, especially those associated with valvular lesions in which dilatation has occurred, that these drugs are used. Among them are some of the most valuable remedies. known to medicine. The most important members of this group are those belonging to the “digitalis series,” including digitalis. itself, strophanthus, scilla, convallaria, adonis, erythro- phlceum, helleborus niger, etc. Caffeine and strychnine, as far as their action upon the heart is concerned, also belong to the group of cardiac tonics. The Digitalis Series.—The “ digitalis series” embraces. a number of substances derived from various families of the vegetable kingdom and having little in common as. regards their chemical’ composition; some substances. found in the animal and even in the mineral kingdoms. may be included in this series. The bond that unites. these various substances is a peculiar and specific influ- ence upon the heart; the action of any one member is. almost identical with that of all the others and different. from almost all other substances. So great is this similar- ity of action that pharmacologists do not hesitate to apply the discoveries made concerning one member to all the others and speak of the action of “digitalis,” although the experiments in questions were made with some other member. | The three drugs of this series which are most used are: digitalis, strophanthus, and scilla, and most of the physio- logical experiments have been made with these, especially with the first two. : Few. drugs in the Pharmacopeia have been the subject. of so much discussion as digitalis, and even yet writers. are not in accord as to some of its physiological actions. Clinicians formerly classed it with the cardiac sedatives, although now it is placed first in the list of cardiac stimu- lants or tonics. Different experimenters have credited it with having nearly every action upon the vascular mech- anism which it is possible fora drug to have. These discordant results are all the more remarkable as they are: not due to the workers having used different prepara- tions; almost any preparation of these drugs, provided it. is active at all, will produce the effects typical of the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Cardiac Stimulants, Cardiae Stimulants, series. The real source of trouble has been that the pharmacologists and physicians have failed, until very recently, to make use of the advances in methods of work and of the facts discovered by modern physiology Very little knowledge of the action of digitalis upon the circulation can be obtained by its administration to healthy men beyond the fact that the pulse first becomes very slow and later intermittent and irregular. The apex beat is stronger and the arteries feel more tense. At the same time the irritability of the heart seems to become abnormally great; slight exertion may cause it to assume a rate of 120 to 130. Experiments upon the frog’s heart have played a very important part in the history of the study of the physio- logical action of digitalis; the greatest service such ex- periments have rendered is the proof that the action of digitalis is primarily upon the cardiac muscle. The changes brought about in the frog’s heart are readily observed by exposing the heart and injecting the drug into a lymph space. The heart soon becomes slowed, but the essential feature is that the ventricular systole becomes more complete. The blood is more completely expelled from the heart, and during each systole the ven- tricle becomes almost white; it also remains contracted for a longer period. The diastole becomes shorter and then less complete; the time relations between systole and diastole become almost reversed. Instead of a short, sudden systole and a long-continued diastole, as normally, the systole becomes very long while the diastole is a sudden, imperfect relaxation of very short duration which merely interrupts for an instant the prolonged contraction. Finally the ventricle stops in systole; it is firmly contracted and white, while the auricles are dis- tended with blood and may contract feebly for a short time. Before the ventricle is finally arrested certain irregularities usually appear. One part of the ventricle, usually the apex, does not relax during diastole and the blood is thrown against the relaxed walls of the other parts causing little bulgings. Or the ventricle may assume a mottled appearance from there being numerous small areas of muscle which remain contracted. The blood may be thrown from one side of the ventricle to the other, the heart undergoing the “ peristaltic contrac- tions” so often mentioned by German writers. The picture of the frog’s heart under digitalis is an extremely characteristic one, and such an experiment as the above is of much more value as a means of identify- ing one of this series in toxicological examinations than are most of the chemical tests. If, after the ventricle has stopped, the intracardiac pressure be increased, the heart will commence beating again, showing that the cardiac muscle is not in a condi- tion of rigor. If apomorphine, or some other drug which tends to paralyze the heart muscle, be applied to the contracted ventricle, the latter will relax and commence beating again. These facts led Schmiedeberg to the view, which has been widely accepted, that the essential action of digitalis upon the cardiac muscle is a change in its elasticity. There are certain facts which make it diffi- cult to accept this view of Schmiedeberg’s, and the only statement we can safely make is that digitalis tends to increase and prolong the contraction of the heart and to diminish and shorten diastole. The absolute power of the heart muscle—/.e., the pressure against which the heart is able to contract—does not seem to be increased by digitalis. Since the extent of the contraction is in- creased, the effect of digitalis has been compared to an increase in the length of the muscle fibres while their cross section (which determines the absolute power) re- mains the same. That this action of digitalis is upon the cardiac muscle itself, and not upon nervous structures contained in the heart, is shown by the fact that entirely similar changes are produced in the apex of the frog’s ventricle and in the hearts of certain invertebrates which are free of nerve cells. So specific is the action of digi- talis upon the heart that this organ may be completely stopped in systole and yet the frog jump about very much as if it were normal, 7.e., the central nervous system and skeleta] muscles are very little affected when the action upon the heart is at its maximum. These effects of digitalis upon the cardiac muscle are sometimes obscured by the results of a stimulation of the vagus caused by the drug. In some cases after the ap- plication of digitalis the ‘systole is incomplete while the diastole is much prolonged and the relaxation during it very great; the heart may even stop temporarily in diastole. Rection of the vagi or the paralysis of their endings by atropine causes “this picture to change in- stantly and the results are now as those described above. One other action of digitalis upon the frog’s heart is to be noticed, viz., an increase in its irritability. That the irritability ‘of the muscle is increased is shown by the fact that a preparation of the apex of the ventricle which has been exhausted by the transfusion of normal saline solu- tion through it and which has ceased to beat will com- mence again when digitalis is applied to it. Sometimes there is a slight acceleration of the heart immediately after the injection of digitalis; this is doubtless due to an increase in the irritability of the muscle, The study of the effects of digitalis upon the frog’s heart is of importance because the changes produced by it in the mammalian heart can be traced back to the same two factors—an alteration of. the cardiac muscle combined with a stimulation of the cardio-inhibitory nerves The action of digitalis upon the circulation of mam- mals is usually divided into four stages (Schmiedeberg, Archiv fir exper. Path. und Pharmakol., xvi., p. 175, 1882). 1. Rise of arterial pressure accompanied as arule by slowing of the heart. 2. Continued rise of blood pressure with increase in the pulse rate. 3. Continued high pressure with great irregularity of the heart. 4. Rapid sinking of the blood pressure, failure of the heart, standstill, and death. Such a division of the action into stages serves a use- ful purpose in so far as it emphasizes some of the salient points; but as a matter of fact these stages merge into each other and frequently some of the features of one appear in the others. Some of the chief points to be considered, then, are (1) the slowing of the heart, (2) the rise of blood pressure, (8) the secondary acceleration of the heart, and (4) the cause of the irregularity and death of the heart. The slowing of the heart was observed in man by Withering, by whom digitalis was introduced into medi- cine (“An Account of the Foxglove and Some of its Medical Uses; with Practical Remarks on Dropsy and Other Diseases,” Birmingham, 1785). Withering was chiefly interested in the ‘diuresis produced by digitalis and paid but little attention to its action upon the heart, although he remarked “that it has a power over the motion of the heart to a degree yet unobserved in any other medicine and that this power may be converted to salutary ends.” John Ferriar wrote an essay in 1799 on the action of digitalis in which he states that the chief action is to slow the heart. The first efforts to discover the cause of this slowing of the heart seem to have been made by Traube in 1851. Traube found that the slow- ing was removed by section of the vagi, and he therefore ascribed it to a stimulation of the cardio-inhibitory centre in the medulla—an explanation which has received abundant confirmation. Occasionally digitalis causes a slight slowing of the heart after section of the v: igi; this has been shown to be due toa stimulation of the vagus end- ings intheheart. The irritability of the vagi is increased by digitalis, for a stimulation of these nerves which was inefficient before, will slow the heart after, its administra- tion. An attempt was made to show that the stimulation of the vagus centre was not a direct effect of the digitalis but a secondary effect due to the rise of blood pressure ; this is disproved by the fact that the heart is often slowed although there is no rise of blood pressure. Thomas observed that digitalis sometimes failed to slow the heart in pneumonia; Brunton and Cash investi- gated the cause of this and reached the conclusion that it 697 ' Cardiac Stimulants. Cardiac Stimulants, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. was due to a partial paralysis of the medullary centres of the vagi by the fever so that they were no longer easily stimulated by the drug. Hence if digitalis is given in a case of fever, the rate of the pulse is not always a safe guide as to whether the drug has been given in sufli- cient quantity to affect the cardiac muscle. The acceleration of the heart which occurs in the later stages of digitalis poisoning was at first attributed to a paralysis of the vagi, for a number of investigators failed to obtain any slowing of the heart by stimulating these nerves during this stage. This explanation has proved insufficient because in some experiments the vagi retain their control over the heart up to the end, and, moreover, digitalis causes an acceleration of the heart after the vagi have been paralyzed by atropine. Attention was called above to the fact that the irritability of cardiac muscle of the frog isincreased by digitalis, and, as will be shown later, there is abundant evidence that the same occurs with the mammalian heart. Hence at present it is con- sidered that the acceleration may be due in part to the paralysis of the vagi, but that the increased irritability of the cardiac muscle which renders the heart more diffi- cult of inhibition is a more important factor. Ofcourse, the acceleration may be due in part to a stimulation of the accelerator nerves, but there is no clear proof that this is the case. The rise of blood pressure caused by digitalis has been a matter of much dispute. Blake (Hdinburgh Med. and Surg. Jour., April, 1889) was the first to make blood- pressure experiments with digitalis; he concluded that the rise was due to a contraction of the capillaries and other peripheral vessels. A group of German investigat- ors (among them Schmiedeberg and his pupils) have al- ways maintained that the increased strength of the heart beat is the cause of the rise of blood pressure. They based their view upon experiments upon the frog’s heart as well as upon deductions drawn from the behavior of the mammalian heart. There has been much discussion as to whether the vaso-constrictor centre is involved in the rise of pressure; there isno question that a marked rise occurs after section of the spinal cord, but it is not yet settled whether, in the intact animal, stimulation of the vaso- motor centre may not be a factor in the cause of the rise of blood pressure. A large amount of evidence has accumulated which shows that the peripheral vessels are constricted by digitalis. Thus Donaldson and Stevens (Journal of Physiology, iv., p. 165, 1888) observed a marked diminution in the outflow from the veins of a terrapin (in which the central nervous system had been destroyed and the heart removed) when digitalis was added to the solutions transfused through the vessels. Similar results have been obtained in transfusion experi- ments with the kidneys and other “surviving ” organs of mammals. On the whole the evidence is very strong that, ina normal animal, the constriction of the arterioles, due to a direct action upon their muscular walls, is a very, perhaps the most, important factor in the rise of blood pressure. Stimulation of the cardiac muscle is an- other factor, and it is probable that there is also some stimulation of the vaso-constrictor centre. In the case of a man with incompetent valves, the heart action is prob- ably a much more important factor in causing the rise of blood pressure than it is in a normal individual. This point will be discussed later. The fall of blood pressure and the irregularities of the heart in the late stages of digitalis poisoning are attributed entirely to changesin the heart. It has been shown that there is no dilatation of the arterioles, as was once sup- posed to be the case, even after very large amounts of the poison. Until comparatively recently very little was known as to the details of the changes produced by digitalis in the mammalian heart; that the strength of the beat is in- creased was generally inferred from the experiments upon the frog’s heart. Moreover, several English physicians in the earlier part of the century (e.g., Beddoes and King- lake, 1801) had reached the conclusion, from studying the pulse, that while digitalis slows the heart, the strength 698 of the beat is not decreased, but is, on the contrary, in- creased. The increased energy of the heart’s contraction is also evident froma study of the pulse waves in an animal deeply poisoned with chloral. Chloral causes a complete relaxation of the arterioles. If digitalis be ad- ministered to an animal in which this has occurred the pulse waves are greatly increased, indicating that the heart is expelling more blood at each contraction. It. has been a debatable question whether this increased out- put of the heart is due to a change in systole or in dias- tole. Schmiedeberg (“ Grundriss der Arzneimittellehre,” dritte Auflage, p. 168, 1895) and Williams (Archiv fir exper. Path. und Pharmakol., xiii., p. 9, 1880) maintain that there is an increased diastolic extensibility without any change in the contractility. According to these au- thors, the elastic resistance of the heart is diminished and there is an increased diastole. As the heart contracts to its former volume in systole more blood is expelled and consequently more work accomplished. More recent workers have adopted the view that the essential change is one in systole, but that this is com- bined with the effects of a stimulation of the vagi (Cushny) or of the vagi and accelerators (Francois-Franck). Fran- cois-Franck (Clinique Médicale de la Charité, Potain, p. 549, 1894) pointed out the resemblance between the action of digitalis upon the heart and the effects of the simultaneous stimulation of the vagi and accelerators; in each case there is a slowing of the pulse but an in- crease in its force. At the same time the increase in force is due, according to this author, in part to a direct muscular action. Ina later paper (Comptes rendus de la Société de Biologie, 1897, p. 111) he seems to lean toward the view that the change in the muscle is a more im- portant factor than he at first supposed. Cushny (Jour- nal of Experimental Medicine, ii., p. 254, 1897) advanced, independently, a theory for the action of digitalis very similar to that of Francois-Franck, except that he ascribes those changes which the French writer thought to be due to a stimulation of the accelerators entirely to the mus- cular action. As the methods used by Cushny are probably more exact than those of others his results will be given in some detail. Cushny studied the effect of digitalis upon the heart by means of the myocardiograph and the cardi- ometer of Roy and Adami. The former is an instrument with which the distance between two points on the heart’s surface and their movements relative to each other are recorded. The curve made by this instrument is similar to an ordinary muscle curve and shows not only the rate of the heart beat but also its strength and changes in tonicity; 7.e., whether the heart tends to as- sume the position of systole or that of diastole. The cardiometer measures the volume of the heart in its suc- cessive phases and therefore records the amount of blood expelled from the heart. The experiments of Cushny were made upon dogs and cats. The action of digitalis may be divided into two stages: the first stage is char- acterized by a slow pulse due tostimulation of the vagus, while in the second stage the heart is accelerated. In both stages there are very important changes in the car- diac muscle. The first stage may be divided into the “therapeutic stage” and a stage of “excessive inhibi- tion”; the latter stage doesnot always occur. The early part of the first stage is the one of greatest interest as it is the only one desired in the medicinal use of digitalis. Within one or two minutes after the intravenous in- jection of a very small amount of digitalis changes in the heart occur which are characterized by a slowing of the beat and increased excursions of the recording levers toward systole and generally toward diastole. The slowing of the heart, being caused by stimulation of the vagi, is due largely to a prolongation of the diastolic pauses. At the same time the duration of the systole is somewhat increased; but this seems to be due entirely to the slowing of the heart, for there is no evidence that the contraction of the mammalian cardiac muscle is pro- longed, as is so markedly the case with the frog’s heart. The increased excursion toward systole of the lever fixed sr ae REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ©27diac SUmulants, - Cardiac Stimulants, to the ventricle shows that this cavity is emptying itself much more completely than it normally does. It is gen- erally recognized that normally the ventricles do not empty themselves completely so that at the end of systole they containsome blood. Under the influence of digitalis the blood remaining in the ventricle at the end of systole Dy N’ D Fig. 1141.—Tracings of the Ventricular Contractions under Digitalis in Experiments on Two Dogs. NV, N’, Normal contractions; D, D’, contractions under digitalis. The levers move upward during systole. In D the rhythm is slower and the movements extend further upward and downward than in JN, i.e., the contractions are more complete and the dilatation during diastole is greater. In D’ the rhythm is slower, and the tracing extends further upward than in N’, but reaches almost the same point below, i.é., the contraction is stronger, but the dilatation is scarcely changed. (From Cushny.) is much less than before. This increased contraction of the ventricle is due to an action of the drug on the cardiac muscle, just as in the frog’s heart. The papillary muscles undergo the same change as the rest of the ventricular wall, contracting more strongly and more completely than before the administration of the drug. The intraventricu- lar pressure during systole was found by Francois-Franck to be much increased. The relaxation of the ventricle during diastole varies considerably in different conditions. As is well known, stimulation of the vagus always tends to increase the relaxation of the ventricle, but in the case of digitalis this action is opposed by the direct effect of the drug upon the heart muscle. The result depends upon these opposing factors, and the effect of these again depends, largely, upon the condition of the heart. If the heart is normal or does not dilate much during diastole, digitalis increases the relaxation (Fig. 1141, D). If, how- ever, the heart is weak and dilated digitalis tends to lessen this dilatation so that the relaxation of the ven- tricle during diastole is less than before the administra- tion of the drug; this is always the case if the vagus terminations have been paralyzed by atropine (see Fig. 1142, B). In the auricles the same forces are at work as in the ventricle. The direct muscular action tends to cause a more complete contraction in systole while the stimula- tion of the vagus opposes this action as well as causes a slowing of the beat. As is well known, stimulation of the vagus produces a much greater effect upon the auricle than upon the ventricle, while there is a much smaller amount of muscular tissue upon which the digitalis can act directly. Hence after even a comparatively small dose of digitalis the inhibitory action may at times pre- dominate and thus greatly reduce the extent of the con- traction of the auricles and so the volume of blood ex- pelled. With ordinary medicinal doses, however, the effect upon the auricles is very much the same as that upon the ventricles: the heart beat is slowed, but the contraction in systole is increased while the relaxation in diastole is not much influenced. — It is clear that the output of the ventricle at each beat must be increased by digitalis, for the ventricle usually contains more blood at the beginning and less at the end of systole than normally. If the rate of the heart re- mained the same, it is evident that the output per unit of - time would also be increased. But the slowing of the heart tends to reduce the total output; hence only cardiometer records can show which of these opposing factors prevail. Asa matter of fact, Cushny found that the output of the heart per unit of time (e.g., ina minute) was uniformly increased by small doses of digitalis; this increase amounted at times to fifty per cent. With somewhat larger doses the inhibitory action may become extreme and now the output is diminished. The output is increased again when the heart becomes more rapid. During all the early part of the first stage the rhythm of the heart is normal; each beat of the auricles is followed by one of the ven- tricles, and the two sides of the heart beat together. If the drug is pushed the slowing becomes extreme and, as always happens when the vagus is strongly stimulated, the rhythm is dis- turbed. The muscular action may be } . . “Le: entirely concealed by the inhibitory action so that the systoles become weaker and less blood is expelled; as a rule, however, the output per beat is still greater than normal while that N per unit of time is less owing to the slow rate of the heart. The auriculo- ventricular beat may be more or less dissociated and the two chambers beat at different rhythms. Sometimes this is due to the excessive inhibition pre- venting the impulses from the auricle reaching the ventricle, a “block” being formed between the two chambers. At the same time the irritability of the ventricular muscle may be so increased that the ventricle assumes a rhythm entirely independent of the auricle; this “idio-ventricu- lar” rhythm may be more rapid or slower than that of the auricle (see Fig. 1148). These changes in the rhythm of the heart always indicate a grave condition of poison- ing and are not met with in the therapeutic use of digitalis. During the second stage of the action of digitalis the muscular prevails over the inhibitory action. The pulse becomes very rapid, the inhibitory nerves no longer being able to keep the heart in check. The auricles are often later in being accelerated than the ventricles because the re B A Fic. 1142.—Tracings of the Movements of the Ventricle (Lower) and Auricle (Upper) under Digitalis. During systole the levers make an up-stroke. In this experiment the inhibitory terminations had been paralyzed, so that only the muscular action is developed. A, Normal; B, after digitalis. The rhythm of the heart is slightly accelerated in B, and the levers extend further upward, indicating a more perfect systole in both auricle and ventricle. The ven- tricular lever does not reach so far downward in B, i.é., the ven- tricular diastole is less complete. (From Cushny.) inhibitory nerves have a greater influence over them. The difference in rhythm of the two divisions leads to very characteristic variations in the strength of the con- tractions of both auricles and ventricles. Numerous other forms of irregularities occur which it is impossible 699 Cardiac Stimulants, Cardiac Stimulants, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. to describe ina few words. They have many points of resemblance to those described under aconitine and can all be traced to the increased irritability of the cardiac muscle and to the interference of the (independent) auricular and ventricular rhythms. (For detailed ac- counts of these irregularities, which are of toxicological rather than of pharmacological interest, see the elaborate descriptions of Cushny, Knoll [Sitzb. der Wiener Akad., xcix., Abth. iii., p. 31, 1890, and ciii., Sitz. November 8th, 1894], and Francois-Franck.) Many of the forms of irregularity can be imitated in the normal animal by electrical stimulation of different parts of the heart (see Cushny, Journal of Physiology, xxv., p. 49, 1899). Stimulation of the accelerators or of the vagi will often cause the most irregular heart to become regular again, gall UII | JULI UUUUULUULIU UU | Fic. 1143.—Tracing of the Auricular (Upper) and Ventricular Movements (Lower) under Dig- italis, as the First Stage Passes into the Second. During systole the leyers move upward, during diastole downward. The rhythm of the two chambers is at first the same, but soon changes, the auricle maintaining its rapid beat, while the ventricle becomes slow and At the end of the tracing the ventricle again becomes rapid, while the auricles The strength of the contractions and the extent of relaxation of the ven- tricular muscle remain little altered, while the auricle rapidly weakens in strength, but irregular. become slow. improves again at the end of the tracing. (From Cushny.) and there is some evidence that the tonic activity of the accelerators is an important factor in counteracting the tendency of the heart to become irregular from digitalis. Eventually the heart passes into delirium cordis owing to the excessive stimulation of the cardiac muscle. After death the mammalian heart is found widely dilated in diastole, not contracted in systole as is the case with the frog’s heart. Thus there seems to be a difference be- tween the effects of digitalis upon the hearts of warm and of cold blooded animals—the former stopping in diastole, the latter in systole. Francois-Franck main- tains, however, that this difference is only apparent; that the heart stops in systole in both cases, but that the mammalian heart is incapable of remaining long in this condition. There has been considerable discussion as to whether the two halves of the heart are influenced alike by digitalis. Some have claimed that one ventricle was more powerfully stimulated than the other and that they at times beat at entirely different rhythms. Later writers, using more exact methods, have failed altogether to confirm these results. The auriculo-ventricular rhythm may be disturbed but the two aruricles and the two ven- tricles always beat at the same rate, although variations in the strength of the beat may occur in one chamber independently of the other. Experiments upon the isolated mammalian heart give results in entire accord with those obtained by Cushny upon the heart in connection with the nervous and vascu- lar systems. Tschistowitsch (Centralbl. fiir Physiol., i., p. 133, 1887) showed, several years ago, that helleborein stimulates the isolated heart and increases its output per unit of time. Recently Hedbom (Skand. Archiv fiir Physiol., viii., p. 185, 1898) has described in detail the action of digitalin upon the isolated rabbit heart. Im- mediately after the drug reached the heart there was a slight acceleration, just as we have seen to be the case when digitalin isapplied to the frog heart. This primary acceleration was followed by a long-continued slowing during which, however, the amplitude of the beats was 700 } much increased. If the heart had from any cause be- come irregular, small doses of digitalin caused it to be- come more regular as well as more powerful. If the amount of digitalin was increased, the heart beat became rapid and the various kinds of irregularities described by Cushny were produced; then there was a sudden short- ening of the ventricle (amounting in some cases to four- teen per cent. of its length) and the heart soon stood still. Bock (Archiv fiir exper. Path. und Pharmakol., xli., p. 175, 1898) studied the action of helleborein upon the iso- lated mammalian heart, using a method differing in some respects from that of Hedbom; the results were, how- ever, essentially the same. Bock emphasizes especially the rise of pressure which occurred in the tubes by which the peripheral vessels were replaced in his experiments and which resulted from the: in- creased output of the heart. In one experiment in which the heart had been beating feebly, helleborein caused the pressure to rise from 29 mm. to 80 mm. of mercury—a strik- ing example of the power of the drug to stimulate the cardiac l muscle. To sum up the results of these ex- periments upon the heart, digitalis in small doses slows the heart, but | its chief action is to increase the contraction in systole. This in- creased contraction leads to a more complete emptying of the ventricle and so to a greater output of the heart and a rise of blood pressure. In the normal animal, with perfect valves, and in which there is no dilatation of the heart, constriction of the arterioles caused by the di- rect action of the drug upon their wallsis probably as important a factor in the rise of blood pressure as is the increased output of the heart. But ex- periments upon animals have shown that the increased output of the heart is especially marked when there is even a slight dilatation of the heart; and the experiments of Bock show what a marked rise of pressure may be produced by the cardiac action alone. When it comes to certain cases of chronic valvular lesions in man in which the dilatation is far in excess of anything we ever have in experiments upon animals, we are justi- fied in concluding that the cardiac action of the drug is by far the most important factor in the rise of blood pressure which undoubtedly occurs. The heart action of digitalis also has a different effect upon the pressure in the veins in cases of valvular insufficiency from its effect in normal animals. In the latter mere increase in the output of the heart is powerless to lower the venous pressure and so relieve venous congestion; only a constriction of the arterioles can bring this about. With incompetent valves, however, the greater con- traction of the cardiac muscle caused by digitalis will lessen the regurgitation and so the backward pressure in the veins; this leads to a fall of venous pressure and so to a lessening of venous congestion. The constric- tion of the arterioles caused by digitalis will add to this result, but the cardiac action alone is often sufficient. Too much emphasis is sometimes laid upon what are, after all, but minor features of the action of digitalis— the slowing of the heart and the constriction of the arterioles. Both of these actions are undoubtedly im- portant in many, perhaps in most cases, but they are en- tirely subordinate to the action upon the cardiac muscle. Aconitine or veratrum viride will cause as great a slow- ing of the heart as will digitalis; strychnine or the extract of the suprarenal glands will constrict the vessels even more strongly, but none of these drugs or any combina- tion of them can replace digitalis. So far we have spoken of the action of “digitalis,” ignoring the fact that several active principles are con- tained in the usual preparations. Our knowledge of the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Cardiac Stimulants, Cardiae Stimulants, active principles is, however, so unsatisfactory and the isolation of some of them is attended with such difficulty and expense that they are not used very extensively in medicine. Schmiedeberg (Archiv fiir exper. Path. und Pharmakol., iii., p. 19, 1874) described three active prin- ciples in digitalis and named them digitalin, digitalein, and digitoxin. Kiliani (Archiv der Pharmacie, 1892-99) has published a series of papers in the earlier of which he stated that the digitalein of Schmiedeberg was probably a mixture of digitalin and some inert substance; he also de- scribed a new glucoside occurring in the leaves which he named digitophyllin. According to these earlier investiga- tions of Kiliani the leaves, from which the pharmacopeial preparations are made, contain three glucosides, digitoxin, digitophyllin, and a body resembling digitalin; digitalin itself is probably absent. All of these glucosides have a similar action, but digitoxin seemed to be the most abun- dant and was found to be by far the most active. In fact digitoxin is one of the most toxic substances known. From these investigations of Kiliani it seemed that the pharmacopeeial preparations owed their activity largely to digitoxin, although the almost complete insolubility of this body in water and its extremely irritating properties made it difficult for some to accept this view. Very recently Kiliani (Archiv der Pharmacie, ccxxxviii., p. 464, 1899) has confirmed the old statement of Schmiede- berg that there is a distinct body, digitalein, easily solu- ble in water and which occurs in both the seeds and leaves. Bohm (quoted by Kiliani, loc. cit.) believes that the activity of the infusion is due very largely to this digitalein. This work is so recent that no experiments seem to have been made to determine to what extent digitalein can be used instead of the galenic preparations. Experiments had already indicated that neither digitalin nor digitoxin could entirely replace the tincture and infusion in therapeutics. A very large number of other plants contain substances witha physiological action very like that of digitalis. A few of these are used in medicine, while others are of in- terest chiefly because they have been used as arrow or ordeal poisons. It is known that there are minor differ- ences between the action of some of these substances and that of digitalis; some, for example, have a greater effect upon the heart and a less effect upon the blood- vessels, others stimulate the vagus centre very power- fully, etc. Few comparative studies have been made, however, although they are extremely desirable. Some of the other members of this series will be men- tioned, and the-points in which their action differs from that of digitalis noted when this isknown. Strophanthus hispidus and 8. Kombé contain a body, strophanthin, which is usually considered to be a glucoside. Strophan- thin acts as powerfully upon the heart as does digitalis but has less effect in constricting the vessels; it does not cause as great a rise of pressure in the pulmonary artery ‘as does digitalis. Erythrophleein (a glucosidal alkaloid, derived from Erythrophlceum, sassy or casca bark) seems to act less upon the cardiac muscle and more upon the vagus centre than the others. Squills contains a gluco- side, scillain, about which very little is known. Prepara- tions of squills act upon the heart like digitalis, but they are used less for this action than for their action as ex- pectorants and diuretics; it is very probable, however, that their cardiac action is an important factor in bring- ing about the changes in the respiratory mucous mem- brane and in the kidneys, for the circulation through these parts is improved by the drug. Helleborein (the glucoside found in Helleborus niger) and convallamarin (derived from the lily of the valley) are both very solu- ble in water, and it was hoped that they might prove valuable remedies when it was desired to use pure sub- stances. Extended observations have shown them to be unreliable, and when they are used at all it is in the form of the galenic preparations. Euonymin (from Euonymus atropurpureus, wahoo) is used as a purgative rather than as a cardiac stimulant. Some of the other substances belonging to this series are apocynein (from Apocynum cannabinum, Canadian ’ hemp), adonidin (from Adonis vernalis, pheasant’s eye), antiarin (from Antiaris toxicaria, the upas tree), one of the most powerful substances of the series; neriin and neriodorin (to which the poisonous properties of nerium or the oleander are partly due), thevetin and cerberin (from thevetia), coronillin (from coronilla) and tanghinin (from Tanghinia venenifera). The arrow poisons quabain and echujin also belong to this series. The skins of certain toads were formerly used as remedies for dropsy. Modern investigations have shown them to contain a poison, phrynin, which has an action upon the heart-very similar to that of digitalis. Epine- phrin, the active principle of the suprarenal glands, also resembles digitalis in some of its physiological proper- ties. The salts of barium have an action upon the heart and blood-vessels similar in many respects to that of the digitalis series. For a discussion of the use of these drugs in thera- peutics the reader is referred to the articles on Heart Diseases; only a few of the more general indications for their use can be given here. It has been shown that the circulation is influenced in three principal ways by medicinal doses of digitalis: the pulse is slowed, the heart contracts more completly in systole so that the pulse volume is increased, and the peripheral arterioles are constricted. Of these the second action is by far the most important in therapeutics. The action of digitalis in slowing the heart is taken advantage of in treating some cases of palpitation, of “irritable heart,” and in a number of other cases, as in certain stages of valvular diseases, acute febrile conditions, etc., in which the heart is beating feebly, but rapidly and irregularly. On the other hand, the slowing of the heart is in some cases an undesirable feature of the action of digitalis, for, as has been already shown, it is due to a stimulation of the in- hibitory nerves, and the latter has an effect just the op- posite of the action of the drug upon the cardiac muscle. It is the inhibitory action which often prevents an in- crease in the contraction of the auricle; in fact, a diminu- tion of the force of the auricular contraction is often observed. The same effect is produced upon the ven- tricle, but here the muscular action is able to overcome the inhibitory action to such an extent that the latter is not usually a disturbing element. A drug in which the muscular action of digitalis was well marked while the inhibitory action was minimal, would doubtless be much more valuable in many cases than digitalis. In erythro- phiein the inhibitory action is well developed while the muscular action is but little marked; unfortunately no drug is at present known in which the opposite is the case. The constriction of the arterioles by digitalis is in many cases a desirable feature of its action, for by it the general blood pressure is raised and the blood accumulates in the arteries and excessive venous pressure is relieved. The constriction of the arterioles seems to be a factor in the production of diuresis; at least strophanthin which does not have so marked an effect upon the arterioles causes much less diuresis than does digitalis. In many cases, on the other hand, it has been found desirable to counter- act the effect of digitalis upon the arteries while retain- ing its action upon the heart. This result is obtained by combining the digitalis with some drug (usually a mem- ber of the nitrite group) which causes a dilatation of the peripheral vessels; or the difficulty may be got around by the use of strophanthin, which does not constrict the vessels very greatly. It isin virtue of its action upon the cardiac muscle that digitalis is chiefly used in medicine and by which it is en- abled to play a role which can be filled by no other sub- stance. Dilatation of the heart from almost any cause, provided that extensive degeneration of the cardiac muscle is not present, is the indication for its use, In such a case the action is very simple and is almost specific. In dilata- tion the heart is not only abnormally relaxed in diastole, but the amount of blood remaining at the end of systole is greatly increased. Digitalis causes a more complete emptying of the ventricle, ¢.e., the pulse volume is in- creased; this and the constriction of the arterioles lead to 701 Cardiac Stimulants, Carlsbad, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. a higher blood pressure and a more uniform flow through the capillaries. Venous congestion is relieved and the nutrition of the various organs, including the heart, is improved. At the same time the relaxation in diastole is usually lessened so that the heart assumes more nearly its normal form. It is especially in dilatation in cases of valvular disease that digitalis is used; in such cases in addition to the above action the drug causes a contraction of the ring of muscle surrounding the diseased valve, and this tends to limit the regurgitation. Asa result of the increased work of the heart and its better nutrition the condition of the muscular tissue is improved to such an extent that after a time the drug can often be dispensed with for longer or shorter periods. The question is often debated whether digitalis should be used in aortic insufficiency; the theoretical objection has been made that the prolonged diastole might allow time for sufficient blood to regurgi- tate to lead to syncope. Physi- cians seem to hold now that digitalis is just as serviceable in the dilatation accom- panying aortic in- sufficiency as in other cases, pro- vided it is given with care. A lit- tle experiment of Dreser’s (Archiv fiir exper. Path. und Pharmakol., Xxiv., p. 238, 1888) may be mentioned in this connection. The valves of the ventricle of a frog’s heart were destroyed, the ventricle was tied to a perfusion can- nula on one limb of which was an outflow tube. This arrangement repre- sented roughly the condition in aortic insufficiency; the pressure of the liquid in the upright tube represented the aortic pressure, while the side tube, from which the blood was collected, represented the peripheral circula- tion. Blood was led to the heart and the amount ex- pelled from the side tube measured. Digitalis (or helle- borein) was now added to the blood; the heart was slowed so that there was a greater opportunity for the blood to drain back through the broken valves into the ventricle, and if the above theory were correct the out- flow from the side tube (¢.e., the peripheral circulation) should be diminished. Dreser found, on the contrary, the outflow to be uniformly much increased; the in- creased output of the ventricle and the prolonged sys- tole had more than counteracted the effect of the pro- longed diastole. This little experiment is of interest as it shows that the only experimental evidence we have agrees with the clinical evidence that digitalis is useful in aortic insufficiency. Members of the digitalis series are used for other pur- poses than as cardiac tonics, although the heart action probably plays a more important part here than is al- ways recognized. Thus the good results following the use of squills as an expectorant are almost certainly due in part to an improvement of the pulmonary circulation. Several of the series are used extensively as diuretics; the fact that as a rule they produce marked diuresis only when there is a diseased condition of the heart points to the effect upon the kidney being secondary to changes in the circulation. On the other hand some of these drugs produce diuresis in normal rabbits, and occasionally in healthy dogs and man, when there is no evidence that the Fig. 1144. Caffeine. teration caused by caffeine is acceleration. is mechanical. 702 Figs. 1144 anp 1145.—Tracing of the Ventricle of the Dog’s Heart; 1144, Normal; 1145, After The lever moves upward during systole, downward during diastole. The slightly larger excursion in diastole in 1145 (Contrast tracings under digitalis: Figs. 1141 and 1142.) renal circulation is altered; this indicates that some of the series, especially squills and digitalis, have a direct action upon the renal epithelium, but comparatively little satisfactory work has been done upon this subject. There can be little doubt that the extraordinary diuresis pro- duced by digitalis in cases of cardiac dropsy is due largely to an improvement in the renal circulation; the blood is. removed from the veins and collected into the arteries, the congestion of the kidney relieved and a more uniform and active circulation established—a condition favorable for the secretion of the urine. Sparteine, the alkaloid of broom (Cytisus scoparius), has. been included by some in: the class of cardiac stimulants. It has been said to have an action similar to that of digi- talis; recent work (Cushny and Matthews, Archiv fir exper. Path. und Pharmakol., xxxv., p. 129, 1895) has. shown this resemblance to be entirely superficial and that. the drugs have little in common. Broom is used to: some extent as a diuretic in cardiac diseases; it is also said to make the heart beat more regularly, Cactus grandi- florus (cereus) has. been warmly rec- ommended by some clinicians as. a cardiac stimu- lant. Very little is known about. the chemistry of this drug or its. physiological ac- tion; there is cer- tainly no evidence that it belongs to: the digitalis series, as has been claim- ed by some. It is. said to accelerate the heart and to. cause a rise of blood pressure; the latter seems to be due in part to a stimulation of the vaso-motor centre. It is. sometimes combined with digitalis, but is said to be es- pecially useful in certain cases in which digitalis is con- traindicated. It is said to be valuable in cardiac weak- ness due to tea, coffee, alcohol, tobacco, etc. Caffeine.—Caffeine has a very characteristic action upon cardiac muscle which makes it a cardiac stimulant. of great value in some cases; it has also a stimulating action upon the vaso-motor and other medullary centres. The changes in the cardiac muscle have been most care- fully studied in the frog’s heart. When blood containing minute quantities of caffeine is perfused through a frog’s. heart placed in a William’s heart apparatus, the rate of the heart is slightly accelerated and the amount of blood expelled at each beat slightly increased, but the most. marked change is an increase in the force of the beat (Dreser, Archiv fir exper. Path. und Pharmakol., xxiv., p. 233, 1888). The heart is able to contract against a much greater aortic pressure than normally—that is, the “absolute power” of the cardiac muscle is increased. Dreser compares this action of caffeine to an increase in the cross section of the muscle fibres while their length remains the same. Caffeine has thus an action entirely different from that of digitalis; the effect of the latter is: the same as lengthening the muscle fibres while the cross. area remains the same; the extent of the contraction under digitalis is increased, while the absolute force is. scarcely altered. After larger quantities of the drug the heart, becomes. slower and its volume smaller; then the apex ceases to relax with the rest of the ventricle, but remains white and contracted, and eventually the whole heart passes into a. Fig. 1145. The only al- (From Cushny.) REFERENCE HANDBOOK ,OF THE MEDICAL SCIENCES. condition of rigor. In all these respects the action of caffeine upon the cardiac muscle is very similar to the remarkable effects the drug is known to have upon ordi- nary skeletal muscle. Upon the mammalian heart the chief effect of caffeine which has been described is an acceleration of the rate: this acceleration occurs when the heart is entirely isolated from the central nervous system (Bock, Archiv fiir exper. Path. und Pharmakol., xiiii., p. 367, 1900), and must therefore be attributed to a stimulation of the cardiac muscle. No observations seem to have been made upon the effect of caffeine on the absolute power of the mam- malian heart; that the extent of the contractions, and so the pulse volume, is not increased is shown by the accom- panying myocardiograms (Figs. 1144 and 1145). When caffeine is administered to a normal animal the effects upon the heart are somewhat obscured by the simultaneous action upon certain nerve centres. As a rule the heart is accelerated, but at times it is slightly slowed by a stimulation of the centre of the cardio-inhibi- tory nerves. On the other hand, stimulation of the vagi is usually less effective in slowing the heart after caffeine owing to the increased irritability of the cardiac muscle. That the cardiac acceleration is not due to a paralysis of the terminations of the vagi is shown by the fact that it occurs after these have been paralyzed by atropine; the acceleration must be attributed to a direct stimulation of the heart muscle. After larger doses the heart becomes weak, irregular, and arhythmic, resembling the condition seen in digitalis poisoning. The vaso-constrictor centre is stimulated by caffeine: this and the increased output of the heart due to the acceleration cause a rise of blood pressure. The most marked effects upon the circulation are seen in animals in which this has been depressed by such a drug as alcohol. Thus Binz found that the blood pressure of a dog deeply under the influence of alcohol rose from 84 to 120 mm. in ten minutes after the subcutaneous injection of caffeine; the pulse rate was doubled. The respiration was also greatly im- proved. Administered to a healthy man a moderate dose of caffeine causes the pulse to become full and hard; it is also moderately accelerated. Occasionally there is a slowing due to stimulation of the vagi. Theobromine has an action upon the heart very similar to that of caffeine; the peripheral vessels are not con- stricted, however, and so the rise of blood pressure is much less marked. The great diuretic power of caffeine has been attributed to the changes in the circulation, and it is probable that these do exert a favorable influence when the blood press- ure is very low. Under ordinary circumstances, how- ever, the constriction of the blood-vessels antagonizes the diuretic action, and the latter can often be obtained only when the caffeine is combined with such drugs as chloral hydrate or paraldehyde which dilate the vessels. It is now generally held that caffeine and theobromine pro- duce diuresis by a direct action upon the renal epithelium, aus entirely independent of their action upon the circu- ation. The experiments upon animals indicate the class of cases in which caffeine might be expected to give good results in therapeutics. It is chiefly in cases in which the heart is simply weak and in which there is no dilatation that caffeine is indicated; it causes the output of the heart to be increased and the blood pressure to rise. It is especially useful in cases of alcoholic and opium poi- soning, for not only is the cardiac muscle stimulated in these, but the vaso-motor and respiratory centres are also thrown into increased activity. Caffeine cannot be con- sidered a substitute for digitalis, for it has almost no effect upon dilatation of the heart in valvular lesions; it is often used in such cases, either alone or combined with digitalis, but the beneficial results seem to be due much more to its diuretic than to its cardiac action, Strychnine.—Strychnine has come into somewhat ex- tensive use in recent years as a cardiac stimulant; the good results following its use are probably to be at- , upon the heart. Cardiac Stimulants, Carlsbad, tributed to its action upon certain parts of the central nervous system (especially the vaso-motor centre) and: the nutrition generally, rather than to any special action At the same time there is some evidence that the frog’s heart is directly stimulated by small quantities of strychnine while larger amounts weaken and slow it. In the mammal strychnine causes a slight slowing of the heart due to stimulation of the vagus centre. If convulsions occur, the heart becomes acceler- ated just as it does in struggling from any cause. Few drugs have such a powerful action upon the vaso-con- strictor centre as has strychnine. Whether convulsions occur or not the arterioles are constricted to an extreme degree and the blood pressure rises enormously. The irritability of the subsidiary vaso-motor centres in the spinal cord is increased, so that a reflex rise of blood pressure may follow stimulation of a sensory nerve after the influence of the chief vaso-constrictor centre has been removed by section of the cervical cord. Strychnine, like iron, seems to be used rather as an ad- juvant to digitalis in the treatment of heart diseases; at the same time it is frequently recommended in those cases in which digitalis is contraindicated. It is also used in cardiac failure during typhoid and other fevers, shock, etc.; in these cases the action is probably mainly upon the vaso-motor centre. Reid Hunt. CARDIOGRAPHY. See Heart. CARLSBAD (Karlsbad) is one of the most important thermal stations of Europe; indeed, its reputation is world-wide. It is charmingly situated in the northwest- ern corner of Bohemia, some 70 miles from Prague, at an altitude of about 1,160 feet, lying in the narrow valley of the Tepel River among the pine- and fir- clad hills traversed by paths in all directions. There are many beautiful walks and drives in the woods covering the slopes of the valley, and attractive excursions in the en- virons. “The valley in which it lies is shielded from the south and east winds by the mountains, but is exposed to the winds from the north and west, and the climate is consequently somewhat trying and subject to sudden changes in temperature” (Stedman). The native popu- lation is about 12,000, and upward of 30,000 people visit the springs annually. These thermal waters are said to have been discovered in 13847, by the Emperor Charles IV., while hunting, but Carlsbad was known as a health resort a century earlier (Baedeker). “The springs issue from apertures in the rocky shell upon which most of the town is built, and are sixteen in number, all similar in their ingredi- ents, which are principally sulphate of sodium, carbonate of sodium, and common salt. They are chiefly taken in- ternally. They vary in temperature, the hottest having the least amount of carbonic acid gas. Some of the prin- cipal springs are the following (with their temperatures, Fahrenheit scale): “Sprudel, 162.5°—a steaming fountain leaping up at short intervals, and having a capacity of four hundred and fifty gallons per minute; Felsenquelle, 138°; Schloss- brunnen, 127°; Miihlbrunnen, 124.5°; Theresienbrunnen, 122°: Marktbrunnen, 118°. These waters are classed among the sulphated alkaline waters.” The following is the composition of the Sprudel water, according to the analysis of Ragsky, as given by Stedman. “Each litre (1.76 pint) contains: Grams. Grains. PUI PHATE OL SOC «1 a%e016, 0.5/0 sisies se tie bud a\s's) sin. 2.3872 = 35.58 Birlpnate Ole CACM os .cteutatie science asses eles « 168 = 2.44 OHIOTIAE OL SOMEUML 7 eel cie csinro cle vials wis es)e is/are pe o/s 1.080 = 15.45 CaTDONATEOL SOCTUMI ee ae cites ars cuamisie's eleels a- sie sie 1.361 = 20.41 CATHONALE TOL GOIGMID os ere clelcialaceca tic sso nis nieiale state 297 = 4.45 Carbonate Of MAGNESIUM .....ccccesesecceviue 124 = 1.86 CAaPRONALE OL SErOUELUIN cece cclsce ie 8b tcdscisiee -0008 = 012 Protoxide of iron N02= 5.08 Protoxide of manganese .0006 = 009 Fluoride of calcium 0038 = .045 Phosphate of calcium .0002 = .003 SiiGalatrela die Poee et ntas, ta'sielola ols.vieitceticie sia e’et so sre'e 0072 = .108 Carbonic acid in one litre 210.59 ¢.c.’”’ (Stedman). Carmine, Cartilage. Although, as has been said, the waters are now used chiefly internally, there are seven bath houses with mineral, mud, vapor, hot air, and other baths, and with massage and Swedish movements. The Kaiserbad is said to be “one of the most magnificent bath houses of Europe.” The conditions for which the internal use of Carisbad water is beneficial are stated by Weber to be the following: In the first place, affections of the liver, including catarrhal jaundice, frequent attacks of biliary colic, early stages of alcoholic cirrhosis, enlargement of the liver in great eaters, etc. Secondly, habitual constipation, hemorrhoidal conditions in robust persons, some cases of chronic gastric and intestinal catarrh with or without diarrhea, some cases of dyspepsia, uric-acid diathesis, chronic glycosuria in fat people, and corpulence, which is often combined with a weak-acting heart. Enlarge- ment of the spleen is also said to be benefited by these waters, as are also periodic, frequently recurring head- aches connected with abdominal disorders. Disturbances of the female pelvic organs, chronic congestion and en- largement of the uterus, chronic affections of the conjunc- tiva and deeper structures of the eye, and chronic aural catarrh are all likely to be benefited or cured by the Carlsbad waters (Stedman). During the summer the usual time for drinking the waters is from half-past five to half-past eight in the morning, an interval of about a quarter of an hour being allowed after each glass (3 vi.), and the dose being from two to six glassfuls. In beginning a course of treatment the spa physician carefully considers each case, and regulates the habits and diet of the patient. Probably the regularity in daily life and diet has very much to do with the improvement of the patient. The average daily programme of the or- dinary Kurgiiste is outlined by Weber as follows: “Rise early to drink the water, and in the intervals promenade to the sound of the music; walk to some café, and take breakfast at about 9 A.m., consisting of coffee or tea, rolls, and perhaps boiled eggs or ham. At about one o’clock the chief meal of the day is taken; coffee and tea at about 4 P.mM., and a light supper in the even- ing.” Those who have been ordered a course of baths mostly take them in the forenoon, There are a fine Cur- haus and a good theatre; classical concerts are given regularly; there are covered walks; in brief, there is almost everything which will render the stay of the in- valid agreeable and pleasant. There are also good edu- cational facilities. The season lasts from the middle of April to the end of September or October, although one can take the waters at any season of the year. Besides the amount of water drunk at Carlsbad, it is said that about 8,000,000 bottles and 110,000 pounds of the salt are exported annually. An after-cure is always recommended subsequent to a course at Carlsbad. Instead of returning home immedi- ately, and at once resuming his or her usual mode of life, the patient should abstain from active work, adopt a simple diet, and live outdoors as much as possible for some weeks. Carlsbad is reached by various routes in about thirty- one hours (from London): by Cologne, Wiirzburg, and Niirmnberg or Bamberg; by Paris, Stuttgart, and Nirn- berg; or by Cologne, Leipsic, Dresden, and Kromotan. For the major part of the above account of Carlsbad, the writer is indebted to “Spas and Mineral Waters of Europe” (by Hermann and F,. Parkes Weber, London, 1896), to which the reader is referred for much valuable information upon this subject. Edward O. Otis. CARMINE. CARGBA.—A name applied to the leaflets of several species of Jacaranda (fam. Bignoniacee), small trees of Brazil, especially of J. procera (Willd.) Spreng. and J. Caroba (Vell.) D. ©. They contain resinous and slightly aromatic constituents, and the crystalline, apparently in- sective body carobin, but nothing to which any special See Cochineal. 704 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. medicinal properties can be assigned. The drug bears a high reputation and is largely used in Brazil as a remedy for syphilis and syphilitic disorders. This belief, which applies to so many plants of little or no activity, doubt- less results from the indefinite ideas which prevail regard- ing syphilis, all sorts of venereal diseases being included under this name. The drug is generally given in the form of the fluid extract, in doses of 1 to 4 ¢.c. (Mxv. to Ix.). Henry H. Rusby. CAROTA.—Carrot. The root of Daucus carota L. (fam. Umbellifere). This plant is a native of Europe, but freely naturalized in the United States (wild car- rot). The cultivated form is the common table carrot, grown everywhere. The fruits of wild carrot have been used as aromatic diuretics; the cultivated roots are made into pulp as poultices; but neither have any claim to med- ical notice. The coloring matter of carrot root is called carotin. The very small amount of volatile oil consists of pinene and probably cineol. W. P. Bolles. CARTHAGENE BARK. CARTHAMUS. Sce Safflower. See Cinchona. CARTILAGE.—Under this name is classified one of the important members of the group of connective tissues; it is characterized not so much by the structure and arrangement of its cells, as by the peculiar nature of its basement substance. Cartilage occurs in three tolerably distinct forms, the differences of which depend largely upon peculiarities in the structure of the basement substance. These formsare called hyaline cartilage, fibro- cartilage, and fibro-elastic cartilage. The most abundant and typical of these is hyaline car- tiluge. This, in the adult, is found covering the articular surfaces of bone, forming parts of the ribs and of the walls of the trachea and bronchi, and in less considerable masses in other parts of the body. Hyaline cartilage is translucent and of a bluish-white color, is firm in con- sistency, and elastic. Like other members of the con- nective-tissue group, it consists of cells and an intercellular or basement substance. The basement substance is for the most part quite homogeneous in the fresh condition, but it is occasionally very finely granular. By suitable treatment with chemical agents, it may be seen to con- tain, and almost to consist of, exceedingly minute and delicate fibrils, which under normal conditions are merged into a homogeneous mass. The basement substance is said by some observers to be penetrated by minute branching canals which Communicate with one another and with the spaces in which the cells lie. Mucin and gelatin, and arather indefinite substance called chondrin, have been obtained from the basement substance, but our knowledge of the chemical nature of these substances, and particularly of their existence in the cartilage in the natural condition before being exposed to chemical ma- nipulation, is still too indefinite to enable us to speak very positively of its chemical constitution. The cells of hyaline cartilage differ considerably in shape and arrangement in different cartilages and in dif- ferent partsof the same cartilage, depending, apparently, to a considerable degree, upon the conditions of pressure to which they are subject, as well as upon the intimate constitution of the basement substance and the influences under which its development transpires. The cells, except near free surfaces or where cartilage and fibrous tissue join, are in general spheroidal, ovoidal, ellipsoidal, or somewhat flattened at the sides, and lie unevenly dis- tributed in the basement substance. The cell body is finely granular, or in some animals contains delicate fibrils, and may enclose droplets of fat, and pigment particles, or may also contain glycogen. The nuclei— of which there may be one or more—are usually sphe- roidal, sharply outlined, and contain more or less well- marked networks of coarser and finer fibrils and nuclei, in which, during life, in some animals, slow oscillatory movements may be seen. The cartilage cells may lie REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Carmine, Cartilage. singly in the basement substance, but they are more fre- quently arranged in groups of two or four, or more, and the cells forming these groups are apt to be flattened on | the sides which abut on one another. Under normal conditions the cartilage cells completely fill the spaces in the basement substance in which they lie. But on ex- posure to the air, to water, to electric shocks of moderate intensity, to a variety of chemical agents, and under cer- tain pathological conditions, they separate from the walls of the spaces and shrink into irregular-shaped, coarsely granular masses, in which the nucleus may be partially or entirely concealed. This shrinkage may be only par- tial, some portion or points remaining adherent to the sides of the cavities, so that the shrunken cells may ap- pear irregularly stellate or have festooned edges. In this shrunken condition we usually see the cells of car- tilages which have been preserved in alcoholic fluids. In some parts of the articular, and also in the costal car- tilages, the cells lie in large groups, or in longer or shorter rows. At the free surfaces of cartilage, or where it comes in contact with the perichondrium, the cartilage cells are usually flattened, and just beneath the perichon- drium may merge imperceptibly into the ordinary flat- tened cells of the connective tissue. The basement sub- stance immediately about the cartilage cells may be seen, under favorable conditions, to be more transparent than the rest, the more transparent zone being sometimes very thin and sometimes of considerable thickness. This por- tion of the basement substance is called the capsule, and is believed to be that part which was last formed around the cartilage cell. Somewhat similar appearances may be seen not only around single cells, but around all groups which have apparently been derived from some single cell originally occupying their position in the basement substance. The basement substance of hyaline cartilage may, under a variety of conditions, become infiltrated with salts of lime, and thus assume to the naked eye a white, opaque appearance, and under the microscope appear crowded with larger and smaller distinct granules. Under patho- logical conditions the basement substance may become fibrillar as well as calcified. Cartilage is surrounded, except over the articular surfaces, by a vascular layer of fibrillar connective tissue called the perichondrium. The perichondrium contains a varying amount of elastic fibres. The fibrillated fibres of the perichondrium pass on into the hyaline basement substance of the cartilage, into which they become gradually merged. Although ves- eae Fig. 1146.—Hyaline Cartilage from the Head of the Femur of Frog. (xX 700 and reduced.) sels from the perichondrium sometimes penetrate for a short distance into the cartilage tissue, the latter is, in general, non-vascular. DEVELOPMENT OF HYALINE CARTILAGE.—At a very early period hyaline cartilage consists of a congeries of VODs LL —4p rounded cells closely packed together, with a small amount of intercellular substance around each cell. The intercellular substance gradually increases in amount, and the cells divide; new capsules, 7.¢., new portions of intercellu- lar substance, are form- ed around the new cells, while the old capsules are expanded and appear to coalesce with those of adjacent cell groups to form the homogeneous basement substance. In this way the cells become gradu- ally separated from one another, but may still retain a grouping which indicates their primitive relations. Schleicher has shown that in the division of cartilage cells, while the changes in the nu- cleus are in general those common to the indirect mode of cell division (see Cell), the separation of the body occurs, not by a grad- ually deepening con- striction as in cells which are surrounded by a fluid or yielding material, but by the formation of a partition out of the intracellular filaments. This parti- tion finally becomes continuous with the capsule around the new-formed cells, and F thickens with their sep- De aie aration from one an- other. The exact way in which the capsules and intercellular sub- stance originate, whether by a separa- tion of a portion of the periphery of the cells, or whether it is simply formed under their influ- ence, or entirely apart from them, is not certain. Frsro-CartTiLaGEe.—This variety of cartilage is found in the interarticular cartilages of some of the joints, such as the knee and jaw, between the vertebre, at the sym- physis pubis, around the tendons of certain muscles, and at points where tendons are inserted into hyaline cartilage, as at the junction of the ligamentum teres with the head of the femur. The cells are similar to those of hyaline cartilage, but the basement substance is fibrillated, the fibrille being arranged in dense bundles or interlacing in all directions. The cells are frequently arranged in rows between the bundles of intercellular fibres (see Fig. 1147), and are less uniformly distributed than are the cells of hyaline cartilage. This form of cartilage frequently merges, in structure, on the one hand into fibrillar con- nective tissue, and on the other into hyaline cartilage. FIBRO-ELASTIC CARTILAGE (yellow elastic or spongy cartilage).—This form of cartilage is not abundant in the body, being found in small masses in the external ear, Eustachian tube, epiglottis, and in some parts of the larynx. It is tough, opaque, and yellowish in appear- ance. The cells, which are irregularly distributed through the basement substance, are similar in appear- ance to those of hyaline cartilage. Around each cell isa narrow, strongly refractile, homogeneous zone of base- we Ree Fig. 1147.—White Fibro-Cartilage from the Ligamentum Teres at the Point where it is Inserted into the Head of Femur. X 650 diameters. (After Bohm and Davidoff.) a, Fibrous con- nective tissue; 5, fibro-cartilage; c¢, point of insertion of the ligamentum teres; d, hyaline cartilage. 705 Carvacrol, Cassia. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ment substance—the capsule. Outside of the capsule the basement substance is more or less densely filled with coarser and finer anastomosing. and interlacing elastic fibres (Fig. 1148). In addition to the elastic fibres the basement substance contains numerous large and small NN S ae ay >, TAS ea ESS oy ee ES SN Soe = YE LNES x MA) JAS MS 550) . . 4 vy f G =H ( i re As ( ON DS es i s Fic. 1148.—Elastie Cartilage from the Human Ear. »X 760 diameters. (After BOhm and Davidoff.) Ata, in the immediate vicinity of the cartilage capsules, a network of elastic fibres with fine meshes: b, cartilage cell; ¢, elastic fibres. granules, consisting of a material similar in chemical and optical properties to that composing the elastic fibres— the so-called elastic granules. These elastic granules are unevenly distributed through the basement substance. Fibro-elastic cartilage is developed from a hyaline form of cartilage by the formation, in the basement substance, of the characteristic elastic fibres and granules. BIBLIOGRAPHY. For the methods of studying cartilage, see Ranvier’s Traité tech- nique d’Histologie, p. 270 et seq. For literature, see Index Catalogue of Library of Surgeon-General’s Office, U. S. Army, vol. ii.; also Quain’s Anatomy, tenth edition, vol. i., part ii., p. 244. T. Mitchell Prudden. CARVACROL.—Ozycymol. Cymophenol. (CeHs.CHs.- [CH,.CH».CH;|6H). This is one of the active constit- uents of oils of thyme and summer savory, and occurs also in some other plants. It is a thickish volatile liquid, with a specific gravity of about .981. It has a charac- teristic odor. Like thymol, with which it is associated, it is strongly antiseptic. It is very closely related to carvol, having the same composition. Henry H. Rusby. CASANTHROL isa thick and gelatinous emulsion of neutral reaction, composed of casein ointment and ten per cent. of lithanthracic extract. The latter consists of those constituents of coal tar which are soluble in benzol and ether. Casanthrol is soluble in water and when ap- plied to the skin dries like a coat of varnish. However, being pervious to water, it does not prevent, but rather, if anything, tends to increase, the perspiration. It is precipitated by mineral acids, acid salts, and calcium salts; no oil separates from it on warming, and it does not become rancid. Classing it among his water-soluble varnishes Unna considers it a valuable application in chronic eczema and other chronic conditions of the skin. 8. Beck uses it in eczema and prurigo with no unpleas- ant secondary effects. It is the strongest coal-tar prepa- ration which can be employed in inflammatory conditions of the skin; and if desired it may be used as a vehicle for other drugs. W. A. Bastedo. CASCARA AMARGA.—Honduras Bark. The bark of Picrena Vellozii Engl. or of a related species, or, accord- ing to some authors, of an undetermined species of Zariri, syn. Picramnia (fam. Simarubacee). This bark comes from Central America, and is a very highly esteemed 706 vegetable bitter by those who are accustomed to it. There is, with its strongly bitter taste, a peculiar sweet and aromatic flavor not resembled by any other drug. It contains a small amount, about one-half per cent., of volatile oil and about three per cent. of the alkaloid picramnine. 'The latter has the peculiar sweet and bitter taste of the bark and is probably its principal active con- stituent. It, as well as its salts, is amorphous. It isa simple or slightly aromatic bitter of unusually pleasant flavor. Its use as an alterative in syphilis is common, but we have no evidence of any special properties in this direction. The dose is .3 to 1 gm. (gr. v.-xv.). Henry H. Rusby. CASCARA SAGRADA.—Riamnus Purshiana. Chittem Bark; Sacred Bark. “The bark of Rhamnus Purshiana DC. (fam. Rhamnacew)” (U.S. P.). To this definition should be added “collected at least a year before being used.” The genus Rhamnus and the nature of its species and their constituents have already been discussed under Buckthorn. The species here considered is a small tree growing very abundantly in our extreme Northwestern States and northward. It wasintroduced into the materia medica in 1878 and encountered a remarkable degree of prejudice and opposition, being practically boycotted by many of the most influential physicians. It, however, steadily increased in favor and is at present probably the most largely used in professional practice of any Ameri- can drug. During its early history, the bark of a related species, R. Californica Esch., growing abundantly in central and southern California, was frequently substi- tuted for it, but persistent exposure resulted in com- pletely stopping the fraudulent practice, so that adultera- tion and substitution are now almost entirely unknown. The bark is taken off in quills, but these are afterward broken up to save space in transportation. These quilled pieces are of variable thickness, up to nearly one-quarter of an inch. The outer surface is rarely fissured, but is more or less warty, the warts being low and broad. The surface is originally of a peculiar red-purple or purple- brown, but becomes more or less covered with gray lichens. These may grow so as to form a uniform gray covering or a series of gray patches of variable size. Pieces taken from the base or junction with the root, are frequently thrown into transverse wrinkles or semi-folds. The inner surface when fresh is light-yellow, but ex- posure turns it gradually darker until after two or three years it may be nearly black. The fracture is sharp and of a pale yellow. There isa slight odor and a peculiar bitter and somewhat aromatic taste. Preparations of the drug are apt to have a very disagreeable taste and nu- merous formule have been devised for avoiding this dis- agreeable feature. ComposiT1on.—The composition of cascara sagrada is very similar to that of buckthorn in its general nature, though certain differences are manifest. The frangulin- like body is not identical, and the percentage of emodin is muchsmaller. There is a much larger amount of resin and this is divisible into three distinct bodies. It is not. clear to which of these differences the more regular and less griping characters are due. Throughout the recent active discussion of the presence of emodin, or emodin- like substances (anthraquinones) as active constituents. of some of our most important cathartics, there has been shown a disposition to over-rate the effect of such pres- ence as determining similarity of action. It by no means. follows that other constituents are to be ignored in the laxative effects, merely because the anthraquinones are thus active; besides which, we have to reckon with minor differences in the anthraquinones themselves. The dis- tinctly bitter properties of cascara sagrada make it more effective in stimulating appetite and digestion. Like buckthorn, it is much more useful when given in small doses, for some time, to overcome habitual constipation, than when used asa cathartic. It has been at various times: claimed asa useful agent in the treatment of rheumatism, syphilis and similar diseases, and it is so by virtue of its depurative and eliminative properties, but not in any way” eee : REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Carvacrol, Cassia, as a specific. The actual physiological action of cascara sagrada has never yet been worked out, but it is evident that it in some way profoundly modifies the secretory and excretory functions. The fluid extract alone is offi- cial. The doseasa cathartic, taken at night, is 2 to4 c.c. (fl. 3 ss. to i.). Those few who find their rest thus dis- turbed may take it in the morning, or may take a smaller dose. Asan alterative or tonic laxative, the dose is 1 to 2 ¢.c. (Mxv. to xxx.), preferably before meals. Licorice, alkalies, and carminative oils tend to disguise the bad taste. None of the extracted so-called active constituents of the drug are worthy to be compared to its preparations. Henry H. Rusby. CASCARILLA.—“ The bark of Croton Hleuteria Bennett (fam. Huphorbiacee)” (U.S. P.). This species of Croton is a large, widely branched shrub of the Bahama Islands. Cascarilla was imported into Europe about the middle of the seventeenth century, when it was considered a variety of cinchona. It has undoubtedly formerly been the produce of several species of Croton, but at present comes exclusively from the one above named. It is in quills or curved pieces, about one-twelfth of an inch (2 mm.) thick, having a somewhat fissured, easily detached, brown, corky layer, more or less gray from a covering of lichens, and the inner surface smooth. It breaks with a short fracture, having a resinous and radially striate appearance. \Vhen burned, it emits a strong, aromatic odor. Its taste is warm and very bitter. The active principles of this bark are cascarillin, a white crystalline, bitter substance, scarcely soluble in water, to which it owes its tonic properties, and an essen- tial oil, which latter it contains to the extent of some- thing more than one per cent. It also contains some resin and a little tannin. The composition just given indicates the use and value of cascarilla. It is a bright, rather pleasant, aromatic, bitter tonic, with no special qualities other than its taste, to distinguish it in medicinal value from other spicy bitters. It is used occasionally in pastils, and is said to be put into tobacco on account of its fragrance when burning. Alcohol extracts its virtues to the best advan- tage. Dose, asa tonic, lor2 gm. There is no official preparation. The section Hlewteria, of the enormous genus Croton, contains thirty or more plants, a number of which have barks possessing properties similar to those of cascarilla. W. P. Bolles. CASEATION. See Necrosis. CASEIN OINTMENT.—A thick, white emulsion, mis- cible with water and proposed by Unna as a vehicle for the application of drugs to the skin. Its formula is: Casein, 14; potassium and sodium hydroxides (1 to 4), .48; glycerin, 7; vaselin 21; salicylic acid or borax, 1; water, 56. As it dries it leaves a thin coating upon the skin. W. A. Bastedo. CASEOIODIN.—A substance of the nature of thyreo- iodin stated to have been used with good results in myx- cedema. The cedema subsided, the hair and skin be- came soft, the intelligence clearer, and the phlegmatic condition gave place to one of average activity. It is prepared from periodo-casein, and is a white powder containing 8.7 per cent. of iodine. The dose is gr. 4 once or twice a day, increased rapidiy up to gr.i.aday. In overdose it is capable of producing flushing, rapid, weak heart, and prostration. W. A. Bastedo. CASHEW (or Cajvu) NUTS. Anacardium. The ripened ovary, with contents, of Anacardium occidentale L. (fam. Anacardiacee), a large, widely sprawling shrub, or small tree, of tropical America, largely cultivated in all tropical countries for its fruit. The edible portion of this fruit consists of the fleshy enlarged pedicel, and is of the form and size of a medium pear, green or yellow with a red cheek. It is juicy to an extraordinary degree, and is consumed chiefly for its thirst-quenching properties. Unless thoroughly ripe, it is exceedingly astringent. When ripe, the juice is slightly sweetish and slightly acid. This fruit is also manufactured into a wine which is credited in Brazil with special properties as a hepatic stimulant. The ripened ovary, many times smaller than the fleshy portion, is partly hidden in the summit of the latter. It is kidney-shaped, about 3 cm. (1.25 in.) long, brownish-ash colored, and smooth externally. It contains a large, bland, oily, curved, edibleembryo. The pericarp, which is 2 or 8mm. ( in.), thick, is of cavernous structure, and contains when dry a thick or solid, black, extractiform, resinous substance, of exceedingly irritant propertics when applied to the skin. A bassorin-like gum exudes from the stem; an edible milky sap, which also is an indelible dye, flows from the trunk. The resinous extract consists of anacardic acid, and a yellow or brown oily liquid, cardol. This is an intense and dangerous irritant, causing often severe inflammation of the skin and blisters, and even the fumes, when it is burned, are said to have the same properties. It was formerly used as an irritant, and is still so used to some extent in the West Indies. It has no medicinal value here, and is only to be known as a poison. The East Indian anacardium is a smaller but similar product, from Semecarpus anacardium Linn. fil., in the same order. A milder cardol, “ Cardol pruriens,” is ob- tained from its fruit, and has been used also as an irri- tant, and as a basis of indelible ink. It is entirely out of use on account of the danger attending it. Poison ivy, Rhus toxicodendron L., and poison sumach, Rhus vene- natum, arein the same family, and, as well as some other species of Rhus, have a similar inflaming action upon the skin (see Potsonous Plants). W. P. Bolles. CASSIA, PURGING; CASSIA FISTULA.—* The fruit of Cassia Fistula L. (fam. Leguminose)” (U.S. P). The British Pharmacopeia improves upon ours in its definition of this article, under the title Cass¢@ Pulpa, as “The pulp obtained from the pods,” this pulp being the only portion of the fruit used. The drug has been undoubtedly in use for five or six hundred years, but its name is much older, having been transferred to this substance from some variety of cinnamon to which it properly belonged. The tree is a native of tropical Asia, but is extensively cultivated for its beauty, both in the Old World and in the New. It is of medium size and produces long, drooping racemes of beautiful, showy, sweet-scented flowers. The pods are nearly or quite straight, from 30 to 60 cm. long by about 2.25 cm. in diameter (12 to 24 in. by 1 in.), cylindrical, shortly stalked and blunt-pointed. The surface is dark purplish-brown, and although not very smooth it has a dull polish. The dorsal and ventral sutures are marked by broad, flat, longitudinally striated bands running the length of the pod. The position of the partitions is generally noticeable upon the surface by means of shallow, annular constrictions about 5 or 6 mm. (+ to 4in.) apart. The exocarp (shell) is hard and brittle when dry. The cavity is divided by transverse septa into from twenty-five to one hundred chambers, each containing one brown, shining, flattened seed and further filled with pulp. This last, when the pods are fresh, is soft and fills the entire space; as they dry it hardens into a thick, black, extract-like mass which event- ually becomes hard and brittle and only covers the surfaces of the chambers, leaving the seed free and loose. When very dry, the quality is considered to be impaired. This pulp is removed for use by maceration. It has a sweetish, mawkish, mulberry-like taste and smell .and is slightly laxative, but, at least in the dry state in which the fruits reach us, it has very little value. Sugar, gum, and other common vegetable substances are all that have been observed init. Cassia Fistula is retained in the Pharma- copeia as a traditional ingredient of the Confection of Senna. In the south of Europe it is more used. Dose: of the pulp, from 4 to 12 gm. (3i to iij.) asa laxative; 707 Cassia, Castor Oil, as a cathartic, two or three times as much. The official confection contains 10 per cent. each of senna and tamarind, 7 per cent. of prune, 12 per cent. of fig, 16 per cent. of cassia fistula, and one-half per cent. of oil of coriander, the rest sugar. The dose is 4 to 8 gm. (3i to ij.). It is little used. Henry H. Rusby. CASSIA.—Cassra BARK, CasstA CINNAMON, and Cassra Bups. See Cinnamon. CASTALIAN MINERAL SPRINGS.—Inyo County, Cali- fornia. These springs are found near Owens Lake, and are thirteen in number, most of them being cold. One or two are sulphurous, and the others are alkaline and carbonated. The place is being developed as a resort. Some of the waters are also used commercially, and are recommended in cutaneous disease. The following an- alysis of one of the springs was made by Prof. Thomas Price, in 1880: ONE UNITED STATES GALLON CONTAINS: Solids. SOGUIMICATDOMABE! cieicsaieate sia! vislelaeieisiefalere/lsiela'ainiel e's siesta Sodium sul phsateieacacnverccls esse eisineiaietaye sisfetbieinis eleeeteete 1.02 Sodium sulphate (?) . Sodium chloride ... g Potassium chloride 2 30 AMO eaieeae meervaoye ‘ Magnesia .......... alate i SUG ai cae Fae Glace atorotereveeimterece clolatateleie’e Gielemts-ere eteiele steetelevstate 14.28 BOvIC AGI Zigis sates core nisin CFR Sele a eistee levees sale Riatiannetc diate Trace. PHOSPHOTIE BCIOT ereyaiele acloihicteicrerepiaceleleistleteleie ele vinietaietercters Trace NOGUNGS cc ere viohteielos cle eins eiele ainieieletnie stnreletoieistericietireistetaine Trace BLOMING TS occccniicds en cuticce vosesitoraeecen isis Trace APOU bs clois cee: sla cis everutatMolaiossysvetelatacethrelereleteisia Temperature (Fahr.)— Average or normal ,.... 59.5° 59.8° 62.0° 63.9° 71.3° Average daily range....| 12.1 2.1 12.2 12.5 Mean of warmest....... 65.6 64.4 68.8 (fie Mean of coldest......... 53.5 52.3 56.6 58.5 Highest or maximum...| 7 {7 7 82 Lowest or minimum....| 22 32 35 40 Humidity— Average relative........ 80.8% | 81% 75.4% | 71.5% | 75.4% Precipitation— Average. rainfall in TNGHOSS chracctcate tov cise 2.73 5.31 2.98 3.58 58.02 Wind— Prevailing direction ....| N.E. N.E. N.E. S.W. N.E. Average hourly velocity in Miles Pisces es eee 8.5 9 9.6 Eek: 9.2 Weather— Average number of clear GRYRS ccadtacence tees 14 8:5 13.8 14 158.4 Average number of fair Bice donee ieisiesiecds 11.4 14.7 9.2 12.2 149.4 Average number of clear and fair days......... 25.4 23.2 23 26.2 | 307.8 The winter climate is said to be milder than that found upon the east, or Atlantic, coast of Florida. The facilities for bathing, boating, fishing, and hunting are also said to be good. So faras climatic conditions are con- cerned, Cedar Keys differs but little from Tampa, about 100 miles farther south on the same coast, but the former has not become a “resort” like the latter, and has no such accommodations as exist at Tampa. The drainage and water supply are also said to be questionable. A1- though Cedar Keys is reputed to be “extremely health- ful,” one would hardly care to send an invalid there un- 159 Cedar Springs. Cell, less he were sure of obtaining adequate accommodations and favorable hygienic conditions. These latter are quite as essential as a favorable climate in the selection of a health resort. Edward O. Otis. CEDAR SPRINGS.—Preble County, Ohio. Post-OFFicE.—New Paris. Hotel. Accress.—Take Pittsburg, Cincinnati, and St. Louis Railroad to New Paris, 35 miles west from Dayton; thence take carriage one mile to springs. These springs are situated in a rolling section of coun- try, about 1,000 feet above the sea level. The surround- ings are very pleasant and attractive. There are said to be not less than one hundred springs within an area of two square miles. Several are used for medicinal purposes. We presentan analysis of one of them by Dr. A. Fennel: WASHINGTON SPRING. ONE UNITED STATES GALLON CONTAINS: Solids. Grains SOdMM CATDOMATE Frat cis sew cdeleetetastlaces sa eis sisigie siatsne 2.26 Magnesium Carbonate ’iai scisisis crvleis’s ois asleoisielelelos! Cewisieria 5.82 TYOT! CALDONIATO Rs ctenteiine ook Caio bisiclel cratule evaistaye eiiecnistins 1.32 Calelumicarbonate so. ented Sects eek ect stats cidsennen sasiele 3.96 Calcium) sulphate archer ceiices caaieiscec htAslecisivcice sures ao 1.24 Sodium SuIPHAte cesresceriiecoc ecto betetietieis ooislw sais Bais or pielorase 18 Caleiiim PMOSsSpHea tee resis ciete steiete arerstelels otstsia’oosieisisyeieiniom gitar 2.13 Sodium chloride....... alate ec dae bias du dletele sists Si aieiese neste 98 FA LUT INIA, 55, Siers poet ct rate sels a's. wise Yobebatelabans ayejeiateee dleseueinceca tents 22 TOGA Fare avarater eta stars, cle bAreeaheeue sap aleve a riniael aiciaraiecgt sitet okater ste 18.11 The waters resemble those of the Bethesda Spring at Waukesha, Wis., but contain more iron. It is claimed that they are especially valuable in catarrh of the blad- der, in renal diseases, and in dyspepsia. James K. Crook. CEDRON SEEDS.—The seeds of Simaba Cedron(R. Br.) Planch. (fam. Simarubacee). The plant is a small tree of Northern South America, and is considerably cultivated in the tropics. It yields an edible fruit about the size of, and somewhat resembling, a large peach. The soli- tary seed is similar to a Brazil nut in both form and size. In their home, the seeds have a high repute as an antiperiodic, and trials with them here have largely supported these claims. Their use as an alternative of the cinchona products appears well justified. The white or whitish crystalline volatile amaroid cedrin appears to be the active constituent, though the presence of an alka- loid has been claimed. Cedrin is soluble in both water and alcohol. Cedron seed is commonly given in the form of the fluid extract, the dose of which is .06 to .5 c.c. (Mi. to viij.). Henry H. Rusby. CELANDINE. CHELIDONIUM.—“ The entire plant, Chelidonium majus L. (fam. Papaveracee)” (U. 8. P.). In some _ phar- macopeeias the root only has been recognized, but the composi- tion and prop- erties are the same through- out. The drug is little used and will probably be dropped from the Pharmaco- peia at its next revision. This, the only species of the genus, is a perennial herb, with slender branching stem, bright yellow delicate flowers, and an acrid, irritating, disagreeable-smelling yellow juice. The plant is sufficiently described by the Pharmacopeia in its description of the dried herb. “ Root several-headed, branching, red-brown; stem about twenty inches (50 me). 2 ot Se Fig. 1198.—Celandine, Slightly Reduced. Seed enlarged about four times. (Baillon.) 760 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. cm.) long, light green, hairy; leaves about six inches (15 em.) long, petiolate, the upper ones smaller and sessile, light green, on the lower side glaucous, lyrate- pinnatifid, the pinnez ovate-oblong, obtuse, coarsely crenate or incised and the terminal one often three-lobed ; flowers in small, long-peduncled umbels with two sepals and four yellow petals. Capsule linear, two-valved and many-seeded. The fresh plant contains a saffron-colored milk-juice and has an unpleasant odor and acrid taste.” Celandine is a native of Europe, but has been abun- dantly naturalized in the United States, where it affects rich, shaded dooryards. It isan old country medicine, and has been used to dissipate warts and as a dressing for ulcers. Its general composition is very similar to that of bloodroot, but the important alkaloid is chelerythrine, associated with chelidonine, a and 8B homochelidonines and protopine. Thereare also chelidonic and chelidoninic acids. Chelerythrine acts in a markedly different way from its close relative, sanguinarine, lacking entirely the irritating properties of the latter upon the motor centres, which it depresses or paralyzes from the first. It also depresses the muscles. The ends of the sensory nerves are first irritated and then depressed. Chelidonine tends to coun- teract this primary sensory stimulation. The homocheli- donines and protopine are in very small amounts. Their effects are also in the general direction of both sensory and motor depression. Hence the effects of celandine are not violently irritating like those of bloodroot, and are finally soothing and depressing. There is, however, enough sanguinarine, in connection with the primary sensory irritation of the chelerythrine, to make the drug strongly irritating in the first stage of action. It acts as a laxative or a purgative, and has always been regarded as an active cholagogue. Large doses may cause emesis, but the tendency of this drug is purgative, as that of san- guinarine is emetic. There is no official preparation. The dose is 1 to 4 gm. (gr. xv. to lx.), The extract is mostly used, in doses of .5 to 1 gm. (gr. viij. to xv.). The drug has been a favorite domestic basis for poultices, and the juice is a counter-irritant, similar to bloodroot. Henry H. Rusby. CELASTRUS. See Bittersweet, False Climbing. CELERY.—This well-known succulent vegetable, Apium graveolens L. (fam. Umbellifere), is distilled in the fresh state for a delicious volatile oil which is used for flavoring. The fruit, however, is the important part from the standpoint of materia medica. It is similar to: the other cremocarps of the family, but is very small, only one-twenty-fifth inch in ilength, broadly ovate, dark brown, hard, smooth, and:generally contains twelve oil tubes. It is largely used in its own form for flavoring purposes and as a carminative, similarly to its relatives, and in doses of grams ij. to iv. (3 ss. toi.). Its volatile oil, containing limonene, is also largely used for the same purposes. Henry H. Rusby. CELL.—A cell is one of the elementary forms of organ- ized substances of animals and plants. It is irreducible into more simple parts except by mechanical or chemical means; it is therefore the histological element. HisToricaL.—It is to the botanists that the credit of the discovery of the minute structure of living matter is due. At the end of the seventeenth century Malpighi and Grew demonstrated the fact that plant tissue was made up of small spaces with firm walls, and that these spaces were filled with fluid. They called these spaces. cells, from the Latin “cella,” a little cavity or space. Further investigation showed that this plant cell con- tained, in addition to the fluid, a somewhat granular sub- stance and that this granular mass contained a darker spot, which spot we now know to be the nucleus. Investigation of animal tissue by Purkinje, Valentin, Miller, and Henle (1880-40) showed that it was com- posed of elements similar to those of plant tissue. In 1838 Schwann, as the result of his investigations, an- nounced the fact that animal and plant tissues were made up of similar elements, and he defined these ele- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ments, the cells, as “small vesicles, with firm walls, en- closing fluid contents.” As the investigation of the plant cell advanced it was found that in many instances it was completely filled by this granular substance, and it was named protoplasm by Mohl. Further investigation of the animal cell showed that the cell wall was absent in many cases, and the question was raised as to whether these bodies could C, Centrosome; F’, foreign body; H, hyaloplasm ; J, intranuclear network or reticulum; K, karyosome or false nucleolus; LL, linin; M, nuclear membrane; JV, nucleus: Nu, nucleolus; S, spongioplasm; V, vacuole. Fie. 1199.—Diagram of a Cell. be classified as cells. It wasalso found that these bodies were identical in structure with the protoplasm of Mohl, and the term protoplasmic bodies was applied to them by Remak. In 1860 Max Schultze announced his protoplasmic theory of the structure of animal cells. He demonstrated that the cell wall or membrane of the earlier investigators was not an essential part of either the animal or the plant cell; that, as a general rule, the plant protoplasm hada firm wall, but under certain conditions it became divested of it and then assumed the same characteristics as those of the animal protoplasm. Having determined that the element was not a cellor little space filled with fluid, but a formed material, he still retained the term cell of the earlier investigators. We still continue to use the same term, as it has become a fixture in biological nomencla- ture. Schultze defined a cell “as a little mass of pro- toplasm endowed with the attributes of life.” As the investigation of the cell proceeded it was found that this mass of protoplasm was of a much more intri- cate structure than was at first supposed, and that the dark spot, the nucleus, was an important part. This necessi- tated a revision of Max Schultze’s definition, and the fol- lowing was formulated: “A cell is a little mass of proto- plasm, which contains in its interior a specially formed portion, the nucleus.” During the last decade a vast amount of information in regard to the structure of the cell has accumulated. This is especially so in regard to the nucleus and the part it plays in the process of cell division. These dis- coveries will be considered in the discussion of the struc- ture of the cell. STRUCTURE OF THE CELL. Cell body, a. Spongioplasm or cytoreticulum, 1. + Protoplasm, or + >. Hyaloplasm, Cytoplasm, c. Microsomes. (a. Nuclear membrane, b. Intranuclear net- § @. Chromatin. work, 6. Linin. ec. Karyolymph or nuclear sap, d. Nucleoli. 9 Levent or * ) Karyoplasm. 8. Centrosome. 4. Cell membrane. ‘of the cell. Cedar Springs. Cell. Cytoplasm (cell body, protoplasm).—Under the ordi- nary powers of the microscope the cytoplasm has a granular, in some instances a homogeneous appearance; but upon analysis with the highest powers it is found to be composed of two distinct substances: the spongioplasm or cytoreticulum (Fig. 1199, 8), which forms a network or reticulum the spaces of which are filled with what is believed to be a fluid substance, and the Ayaloplasm (Fig. 1199, H). The proportion of these two elements varies. In young cells the hyaloplasm predominates, but as the cells grow it decreases relatively, and the spongioplasm increases. The amount of the spongioplasm, the thick- ness of its threads, and the size of its meshes also vary in different cells. Embedded in the cytoplasm are mi- nute granules, the mzcrosomes ; these, together with the nodal points of the spongioplasm, give the granular ap- pearance to the cell-body. The distribution of the mi- crosomes is not uniform; usually the periphery of the cell is entirely free from them, and then in some cells they are grouped in masses or they may be distributed irregularly. If they are numerous and coarse in character, the cyto- plasm has a dark look; if they are fine and less numer- ous it has a lighter or nearly clear appearance. In addi- tion to the microsomes other objects are sometimes found in the cytoplasm, viz.,pigment or fat granules and clear, spherical-shaped cavities—vacuoles (Fig. 1199, V). In 1892 Butsehli published the results of his observa- tions on the minute structure of cytoplasm. He claimed that the reticular appearance was due to the fact that it was a foum or emulsion, being made up of numerous microscopic vacuoles, the walls of which were in close apposition, so that the microscope showed them only in optical section and not their surfaces. In order to con- firm this theory he made numerous experiments and finally succeeded in producing what he called “artificial cytoplasm,” which when viewed with the microscope had nearly the same appearance as the spongioplasm of acell. This artificial cytoplasm was made by rubbing up olive oil with cane sugar or potassium hydrate. A drop of this mixture was placed on a slide, a small drop of water was added, and the whole was covered with cover glass, the weight of which spread it out in a thin layer. From these experiments he concluded that cyto- plasm was a mixture of fluids of different densities, the heavier forming the walls of the vacuoles, while the lighter collected in their cavities. At present we have two theories as to the structure of cytoplasm: the reticular, which is supported by the ma- jority of investigators, and the foam or emulsion theory, which is advocated by Butschli and his school. Nucleus.—The nucleus or karyoplasm (Fig. 1199, 1) is now known to be the important part of the cell, being the centre of all its activity. It is generally embedded in the cytoplasm, but in a few cells it projects above the surface. It stains, or, more properly speaking, some of its elements stain, with certain dyes, such as carmine, hematoxylin, etc. It may be spherical, oval, rod-like, or irregular in its shape, and its size is generally in proportion to the size In a few instances it is nearly as large as the cell itself (lymphocytes). Every cell, as arule, has at least one nucleus, sometimes two or more, and in the large giant cells one hundred or more have been found. A few cells—red blood cells, the surface cells of the epi- dermis, and the respiratory cells of the terminal air pas- sages of the lungs—are without nuclei. These cells did at some previous time have a nucleus, but in the process of differentiation the nucleus disap- peared. In the resting state the nucleus is surrounded by a membrane, the nuclear membrane (Fig. 1199, I), which encloses the nuclear contents or karyoplasm. This mem- brane is divided into two layers, an inner or chromatic, and an outer or achromatic. By some investigators it is considered as a special condensation of the cytoreticulum. The karyoplasm is made up of a formed material, the intranuclear network or reticulum (Fig. 1199, 7), and of what is believed to be a fluid substance, the karyolymph or 761 Cell, Cell, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. nuclear sap, which fills the spaces formed by the reticu- lum. The intranuclear network is composed of two ele- ments: chromatin, which stains with the nuclear dyes, and linin (Fig. 1199, Z), which does not stain. The chromatin occurs in the form of irregular anastomosing threads, which are supported by the linin. These chro- matin threads vary in their thickness and arrangement. In some nuclei they appear in the form of a thick or thin convoluted thread; in others as rounded or irregularly shaped granules. Some investigators believe that the chromatin occurs in the form of short, rod-like masses and that these masses are embedded in the linin. The linin is a transparent, unstainable substance, only to be dem- onstrated by special methods of preparation. The Nucleoli are of two kinds: the true nucleoli or plas- mosomes (Fig. 1199, Nw), and the net knots or karyosomes (Fig. 1199, A). The true nucleoli are spherical in shape and they stain intensely with the nuclear dyes. They may lie free in the nuclear sap or they may be attached to the threads of the intranuclear network. The karyo- somes or false nucleoli are thickened nodal points of the reticulum. The function of the true nucleoli is un- known. Centrosome.—This is a minute spherical-shaped body (Fig. 1199, C) found within the nucleus in the resting state. It is the special organ controlling the process of cell division. In the earlier stages of this process it passes into the cytoplasm, remaining near the nucleus, and is surrounded by a zone of fine, radiating fibrils, the attraction sphere or archoplasm. In some few cells no centrosome has been discovered as yet, but this is be- lieved to be on account of its minute size and difficulty of demonstration. Cell Membrane.—The cell membrane is now believed to be an unimportant part of the animal cell. It is present in but a few instances—fat cells and the ovum being exceptions. In the ovum it is well developed and has structural differences ; in other cells, however, it is gen- erally of a homogeneous appearance and is considered by many to be a condensation of the cytoplasm. Cells differ greatly in shape. They may be oval or spherical—the form of all young cells; discoid, as in the case of the red blood cells; flat, as in some forms of epi- thelium; cylindrical or columnar, as in the epithelium of the intestine; or, finally, irregular, as in the connective- tissue cells and nerve cells. The element of pressure is an important factor in the modification of the shape of cells, and is well exemplified in the various forms of stratified epithelium. VITAL PROPERTIES OF CELLS.—Under this heading are grouped the phenomena of movement, irritability, metab- olism, and reproduction. Cells exhibit the phenomena of movement under three forms: protoplasmic, ameboid, and ciliary. Protoplasmic movement is difficult of observation on account of the slowness of the process. It has been de- monstrated in a few animal cells, and in plant cells it is easily observed, the streaming of the cytoplasm being an example. All animal cells are believed to possess it to a greater or less degree. It is made manifest by the changes in the form of the cytoplasm, by the movements of the microsomes, and by the changes in the position of the nucleus. Ameeboid movement is similar to that exhibited by the unicellular organism, the amceba. Nearly all animal cells possess it tosome extent, it being well marked ina special few, viz., the leucocytes, lymph cells, and wandering con- nective-tissue cells. Ifaliving leucocyte be studied under the microscope, it will be seen to change continually its form (Fig. 1200). Gradually a bud-like mass of the cytoplasm will push out from some point, or several may start from different points. These pseudopodia may re- tract, or one may be extended for a considerable dis- tance, the remainder of the cytoplasm flowing into it. Other pseudopodia are given off and the above process is repeated. By this means the cell will gradually crawl through the field of the microscope. It is by means of this amceboid movement that the leucocytes pass through 762 the walls of the capillaries and wander through the spaces of the tissues and organs or between other cells. Ciliary movement is the power possessed by the hair- like appendages of certain cells (see Hpitheliwm). Irritability is the property that cells have of respond- ing to external stimuli. These stimuli, taough almost Fic. 1200.—Amceboid Movement. (After Verworn.) innumerable, may, ina general manner, be grouped as me- chanical, electrical, and chemical in their nature, or as due to heat and light. All cells do not react in the same manner to the same stimulus, nor do all stimuli cause the same reaction in an individual cell. The response of a cell to a specific stimulus depends upon its structure. Some, those of the organs of vision, for example, respond to light only ; while others may respond to one or more stimuli. Under mechanical stimuli are classed pressure, violent shaking, and crushing, any one of which causes cells to react in some manner. While heat is a necessary condition for the vital activ- ity of cells, it must be confined within rather fixed limits; these varying considerably, however, for different cells. If the temperature be raised to 40° C. the vitality of the cell is destroyed, but, on the other hand, the temperature may be lowered to a considerable extent without the cel] being killed. An increase of heat above that at which a cell normally exists causes a marked increase in its vital processes, until the heat-rigor point (40° C.) is reached, when a coagulation takes place and the cell is killed. Lowering of the temperature below the normal produces a gradual diminution of activity until the cold- rigor (0° C.) point is.reached, when the cell passes into a “narcotic” state. Apparently cells can remain in this state for a considerable length of time without their vitality being destroyed, for if they be gradually warmed up to their normal temperature their vital functions are resumed. Light, in the higher order of animals, is believed to be a stimulus to the cells of the organs of vision only. In some of the lower animals, other tissue cells, especially those of the skin, respond to its stimulation. Electrical stimuli, when applied in the form of weak currents, cause an increase, strong currents a decrease, in cell activity. If the latter are continued for a consider- able length of time they cause the death of the cell. Chemical stimuli are almost numberless, and at present their manner of action is not thoroughly under- stood. Some cause contraction, some increased move- ment, others increased secretive activity, etc. is} OVE © oo) Oj 0 2.0. 66.0 905 DOL; 9 Bo Mo Oe 0.96 (OShe, Ok ° Of ono 7 Panes Fic. 1205.—Sexually Mature Proglottis of Tenia saginata. OC, Transverse commissure of excretory canals; Cl, genital cloaca; D.st., vitellarium ; H, testicular follicles; NV, lateral nerve trunk ; Ov, ovary; Ut, uterus; W, longitudinal excretory canal. X 10. the rays of afan. The sagittal fibres extend singly or in small bundles from dorsal to ventral surfaces directly through the proglottid; they are scattered and not so numerous as the other systems of fibres. Absolutely no trace of an alimentary tract has yet been discovered in the cestodes. Imbibition is the only known method of taking food, and the adult tapeworms are ac- vit. ut. cir. vd. sh.gl. vit.d. ovd. Ov. Fic. 1206.—Central Portion of the Sexually Mature Progilottis of Dibothriocephalus latus from the Ventral Surface. cir, Cirrus sac; ov., ovary; ovd., oviduct; sh.gl., shell gland; wt.,loop of uterus ; vag., vagina; vd., coil of dorsal vas deferens; vit., vitellaria ; vit.d., yolk duct. The numerous follicular testes lie beneath, 7.¢., dorsal to the vitellaria shown here. (After Sommer and Landois.) cordingly limited to those organs, alimentary canal and serous cavities, in which the parasite is bathed in a nutri- ent fluid. The organs of the reproductive system are grouped so that each proglottis contains a complete set, and even when the body is not segmented externally, examination of the internal structure shows them to be repeated. Each proglottis contains all the organs of both sexes 780 (Fig. 1209) and appears in this respect a complete her- maphroditic individual. The organs first make their ap- pearance in the anterior proglottides as indistinct cords of cells which gradually assume the character of the sexually mature condition. In general the male organs reach maturity a little in advance of the female, and copulation with an older proglottis of the same or of a different chain may hence be inferred. The male system consist of numerous small testes, the vasa efferentia of which unite near the centre of the segment to a common vas deferens, and the latter, which is commonly provided with an enlargement, the vesicula seminalis, and which terminates in a copulatory organ, the cirrus, opens with the vagina into a genital cloaca (c/) at the common genital pore, located either at the margin or on the surface of the segment. The female organs may be said to take their origin from the genital pore with the vagina which leads inward, furnished at some point with an enlargement, the receptaculum seminis, in which the supply of sperm is stored up. The ovary, either single or paired, empties by an oviduct which joins the vagina near the shell gland and which often has near its origin a muscular organ, the oocapt, by which the eggs are taken from the ovary and forced onward to the vagina. The vitellarium is a single, large racemose gland (D.st., Fig. 1205), or a multitude of small follicles (v7t., Fig. 1206) in which are produced the masses of yolk material to be included in the eggs. Vitelline duct and oviduct join the con- tinuation of the vaginal canal in the shell gland, and to this portion of the duct the name ootype has been given. Here the ovum coming from the ovary is fertilized by the spermatazoon from the seminal receptacle, is surrounded by a mass of yolk material from the vitellarium, and the whole encased in a capsule formed by the secretion of the shell gland, which rapidly hardens into a thick chitinous shell. The completed eggs are then forced onward into the uterus. Since they consist not only of a fertilized ovum but also of a mass of disintegrated yolk cells, the name com- pound egg has been applied to them. Such eggs occur only in the flat worms. The uterus may possess a special external opening or may be without such. In the latter case it is small at- first, but with the accumulation of eggs it becomes irregu- larly enlarged by the formation of lateral outpocketings so as to occupy with its branches almost the entire space of the proglottis (Fig. 1207). In the course of this trans- formation other organs gradually disappear until the ripe segment is little more than a muscular sac which encloses the branching uterus crowded with eggs. The manner of branching is characteristic of the species, as is also the way in which ripe proglottides are detached either singly or in groups, and both features together with other de- tails in the structure of the reproduct- ive system are discussed in connection with the individual species. The eggs of the cestodes are oval and provided with a thin shell which is often supplied with a lid. Within this occurs in many eggs (Fig. 1208) Fig. 1207.— Ripe Proglottis of Tenia saginata with branched uterus. “ee (After Braun.) Fig. 1208.—Egg of a thicker second shell, so-called, of a Zenia soliwm. aah Mess: x 380. (After structure characteristic for the family — Leuckart.) in which it occurs. In reality this in- ner structure is not a shell but an embryonic membrane, and takes its origin during the early growth of the germ cell, which occurs in most cases while the egg is still retained in the uterus of the adult cestode. When the uterine egg is examined soon after its formation, the shell is seen to contain a single germ cell surrounded by a number of yolk cells which, in some cases, have lost their cellular identity and constitute merely a mass of granular yolk substance. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. The embryo originates from the development of the egg cell alone while the yolk cells serve as nutriment during its early growth. From the division of the egg } 2 cell, which under- | } Wy Yj there arises a spheri- [H. cal embryo ‘sur- CAE rounded by one or membranes. From the latter may or- goes total cleavage, 4S ——.._moreembryonic Ss SS iginate an inner = ‘ SS shell, as is the case Ses ION . in Teniade (Fig. 1208), or a ciliat- ed mantle, as in Bothriocephalide \\ (Fig. 1209). The \ spherical embryo (Fig. 1210), which is known as_ the onchosphere, is uni- formly character- ized by the presence of three pairs of hooks of variable shape and by great mobility, and in this condition is ready for introduction into the secondary host. This may be the result of a direct migration, as when the ciliated bothriocephalid embryo, swimming about in the water, 48 swallowed by a suitable host; or it may be of passive character, as when the teenioid egg containing an embryo enveloped in its membranes arrives by chance in the alimentary canal of the larval host; in the latter case, at least, it is necessary that the eggs should be introduced into the stomach and be subjected to the action of the gastric juice to disinte- grate the shelland membrane. Were this not so it is clear that the harboring of the adult in the intes- tine would be, in those cases in which the larva parasitizes in the same animal, a source of extensive secondary infection. In such cases it is well known, as for instance in Tenia solium of man,that any reversal of the ordinary peristaltic action of the canal, which brings loose proglottides into the stomach and subjects them to gastric digestion, will re- sult in the release of the six-hooked onchospheres, and in the infection of the host with the larve. Once that the membranes are broken down and the onchospheres set free they bore their way actively, by virtue of the hooks, through the wall, probably in most cases of the proximal portion of the intestine, and are believed to be distributed further by virtue of the portal circulation; at least the liver and the connective tissue adjacent to it are the chief seats of the larve. Having come to rest at such a point the embryo throws off its hooks and forms onits surface a thick cuticular layer beneath which are differentiated the muscle fibres, while about each embryo is formed a cyst by the activity of the host. The \ = Fic. 1209.—Free Swimming Onchosphere of Dibothriocephalus latus in ciliated mantle. X 500. (After Schauinsland.) FiG. 1210.—Free O nchosphere, Magnified. with a loose parenchymatous tissue in which soon appear irregular spaces that later fuse to form a large central cavity. Thus has been reached the first form of the larval stage known as the bladder worm or cysticercus (Fig. 1211). A growth of two to four weeks is sufficient in most cases to bring the cysticercus to the diameter of a milli- Fig. 1211. — Young Cysticercus of Toenia saginata with beginning of Scolex Ingrowth, Seen in Optical fied cat tes meter, when the second stage in the Leuckart.) development is entered upon by the appearance of a meniscoid prolifera- ' tion of cells at some point on the bladder; into this projection there penetrates from the exterior a hollow cylindrical ingrowth of the cuticula (Fig. 1211) forming the starting-point of the scolex of the adult worm. As the growth becomes larger the ingrowth presents the form of a flask (Fig. 1212, A); it is still covered through- centre of the sphere is filled at first Cestoda, Cestoda, out by acuticular layer, and at the base of the flask there arise in reverse the structures which characterize the head of the tapeworm: at the centre the rostellum with its crown of hooks, and on the sides the suckers having, when fully developed, the characteristic form and size (Fig. 1212, B) of the adult. Under proper conditions the head begins to be everted, starting from the base and continuing until, with the Fic, 1212.—Formation of Scolex in Reverse on Cysticercus of Tenia serrata. A, Early stage; B, fully developed scolex. Magnified. (After Leuckart.) neck, it ultimately projects above the surface of the bladder (Fig. 1213). This process may at times take place while the bladder worm is still retained within its host. In other instances the consumption of the flesh in which the cysticercus is enclosed and the digestion of the surrounding tissue form the stimulus for the evagina- tion of the scolex. It is interesting to note that under the influence of the alimentary secretions of the definite host the bladder of the cysticercus is entirely digested, its remnant appearing as a ragged fringe (Fig. 1214, A), at the base of the fully extended scolex and neck. Having attached itself the scolex enters upon a period of rapid increase in length, which is soon ac- companied by the appearance of the first proglottides (Fig. 1214, B). The scolex system of excretory canals originates early (Fig. 1208) even be- fore the suckers and rostellum have appeared, and persist unchanged in the scolex of the fully developed adult. In the formation of the proglot- tides it may be noted that the ter- minal proglottis is the oldest, and that new segments are continually formed in the vicinity of the neck. The sexual organs appear early as strings or masses of embryonic cells in the midst of the parenchyma. Formation of proglottides and growth proceed so rapidly that the tapeworm has matured and set free the posterior joints in a brief period. These reach the exterior with the fecal mat- ter, often manifesting great independ@énce and power in movement. They contain masses of eggs stored up in the uterus with which the beginning of the life cycle is again reached. The normal seat of the tapeworm is in the alimentary canal, and usually in the small intestine, where the worm lies close to the wall with its head more or less embedded in the villi. Occasion- ally one of the smaller species wanders from this place into the ductus chole- dochus, and more rarely into the liver itself. This seems to be the normal habit of a few species not found in man. The occurrence of tapeworms in the human stomach or anterior thereto, as reported by various medi- cal observers, is due either to a post- mortem wandering or to regurgitation. On the other hand the reported oc- currence of Cestoda in the bladder, and the discharge of proglottides from the 781 ts) Fic. 1213. — Cysticer- cus of Tenia ser- rata with Everted Scolex. (After LeuckKart.) Fig. 1214. — Young Tenia serrata. A, Immediately after digestion of bladder by new host; B, with a few proglottides. (After Leuckart.) Cestoda,. Cestoda, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. urethra, can be explained, in so far as the cases do not rest on erroneous observations, only on the basis of in- jury or accidental introduction. Portions of a tape- worm have been at times discharged from abscesses or fistule which have probably had at some time a con- nection with the intestine. Leidy’s discovery of a speci- men in a cucumber admits, however, of no such natural explanation. Though often torpid when examined after discharge, the tapeworm is undoubtedly, it must be re- membered, active in its warm-blooded host. To its con- tractions are due the serious symptoms which often ac- company its presence. Even the discharged proglottides live for several days outside the host under ordinary cir- cumstances and perform migrations and movements of considerable extent. By virtue of this apparent com- pleteness and activity, the separate proglottides are fre- quently diagnosed as flukes. The effect of the parasite on its host may be regarded first from the standpoint of loss of nutriment. This has been carefully computed by Leuckart for the largest hu- man tapeworms, and amounts in one year for a single specimen of Dibothriocephalus latus to from 500 to 700 gm., and for Tenia saginata to from 1,500 to 2,000 gm. Although the presence of a number of individuals may heighten this materially, yet the amount is entirely in- adequate to explain the far-reaching effects which are manifested by man as the result of the presence of only a single one of these parasites. The severe symptoms are noticeably of a nervouscharacter. Anemia is a frequent manifestation, and this displays at times a pernicious ten- dency which in one case at least has terminated fatally. Many of the symptoms affecting individuals who har- bor tapeworms have been attributed to poisons developed by the parasite within the body of the host. Not only is this evinced by the subsidence of the nervous and epileptic symptoms on the removal of the tapeworms, but the affections of the eyesso frequent in those afflicted may naturally be due to the effects of a poison absorbed from the intestine and circulating in the blood. The fluid extracted from a hydatid cyst has been shown by experiment on man and animals to be toxic. To this quality may doubtless be attributed the severe symptoms or even death consequent upon the rupture of such a cyst or its operative puncture. An extract from Diboth- riocephalus latus has been shown to exert a globulicidal effect on dogs, and one of Tenia saginata has been found to kill tubercle bacilli. The symptoms of tapeworm disease are by no means well defined and may include almost any possible com- bination. In experimenting upon himself, however, Stiles noted during the presence of Tenia saginata as the most constant symptom one not heretofore recorded. He says: “During the time of infection it would very fre- quently happen as I walked along the street or across the room that I suddenly felt a peculiar sensation almost ex- actly similar to the sensation one feels upon the sudden descent of anelevator.” Despite the indefiniteness of the clinical aspect of tapeworm infection, any suspicions of such trouble may be definitely tested by a microscopical investigation of the feces. The presence of adult ces- todes will be manifested by an abundance of their char- acteristic eggs. The specifics which are most frequently employed in driving out tapeworms are Cortex granati, of which the effective principle is an alkaloid known as “ pelletierine,” Flores Kouso containing the amorphous kosotoxin, Rhizoma filicis containing the amorphous filicie acid, and kamala with the resinous kamalin (see Anthelminthics). In bringing about the evacuation of the parasite some precautions are necessary to insure success. When a patient is passing a tapeworm the parasite sometimes breaks in two owing to the transition from the warm bowels to the cold air or to a cold porcelain vessel. By the use of a vessel containing warm water this sudden change and its consequent evil effects may be avoided. In the next place cestodes are frequently expelled ina knotted mass, and any obstruction in the lower portion of the canal may delay their passage sufficiently to permit 782 the parasite to secure a new hold on the wall. Con- sequently success may depend upon thoroughly clearing out the canal. The distribution of each species will be considered under its proper heading; here, however, some general items may be noted concerning the frequence of tape- worms. Stiles gives the following table of: CASES OF TAPEWORM IN MAN. Total number SEX OF PATIENTS. Authority. of cases reported. Male. Female. IWAWTUGCK Gin i.sicelce vices sivctslse 173 56 117 Crisp 'higecemitt eietatetemnne eikiereretrs 247 96 151 BERL OM a rare citetnietec lettuce ee 26 10 16 IMOnaGH Ts Bier whe iviese les btctorsteiscere ote 240* 111 129 MROMEL sax/Saltatsiniatcice eis oieeteele 10* 3 7 KYADDON teat wien claimctee eter 367 126 241 IOLA sete niiaateis teres cies 1,063 402 661 * Children. He attributes the evident sex difference merely to the fact that women ordinarily prepare the food, and are hence more exposed to chance infection thanmen. Statis- tics of French maritime hospitals give for the period 1886-90 about 1.5 per cent. of cases for tapeworm infec- tion, and records of the United States hospital service during the war contain a total of only .012 per cent. treated for tapeworms. This percentage is under the circumstances naturally abnormally low as compared with conditions in times of peace. The occurrence of various species in different regions may be adjudged from the following table. Such figures exist only for a very few localities: ow S 4 Alera) on aches 3 s i} =| as . Ss nl ‘Ss =8 |aale s1 + ne |S28] as as |23 he Lael o Authority. | Country.| 23 [534] 8S | B= |SSiSelEs| = Bb KS S\Agi =e) g Parona ....|Milan ....|1899...} 150| 121 1 11 | 4|..|.. | 14 Parond ..ns\ltaly e.cee 1868-99} 513 | 397 Cy AOS ieee ~ 4 19 Krabbe..... Denmark. |1869...| 100 37 53 DCT eerene Krabbe..... Denmark. |1869-87| 200 | 1538 74. IGS Sal Teenie Krabbe..... Denmark. |1887-95| 100 89 At OT 6 ae eee Stiles iors. U8. Ace 1897... 3] ae) Many | Rare | each 1 ete Cestodes have been known from the earliest times, and both tapeworms and bladder worms are distinctly recog- nized in the oldest medical works which have come down to us. One of the hermetic books of the Egyptians, that on medicaments now known as the Papyros Ebers, and dated about 1550 B.c., gives in hieratic writing extensive sections on these parasites and their treatment, which are taken in part from the writings of earlier physicians. The proscription placed by Moses on the use of certain flesh has its undoubted ground in the abundant presence in such animals of bladder worms. Hippocrates notes the presence of echinococcus bladders in man and an operative method for removing them. He also speaks of the evacuation.of fragments like pumpkin seeds as diag- nostic of the tapeworm. Both he and Aristotle speak of the bladder worm of the pig as well known, and advise the detection of its presence by examining the lower sur- face of the pig’s tongue where the cysticerci appear as swellings. This method is followed even to-day. Aris- totle showed also that the tapeworm in contrast with the free round worms of the intestine was attached to the wall of the canal. Pliny adds to the accounts of his predecessors which he quotes only fabulous reports of the length of tapeworms (up to three hundred feet!) and erroneous observations on their presence in cold springs. Galen mentions bladder worms from the abdomen of slaughtered animals and notes the tendency of the liver to “produce” these forms in its surrounding fascia. It was 1600 a.D., however, before even two species were differentiated among human tapeworms, and 1700 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Cestoda, Cestoda, A.D. before the tapeworm head was recognized. About this time cestodes from other hosts began to be studied and the animal nature of the bladder worms, which had previously been regarded as tumors or concretions, was successfully maintained. Even then authors noted the resemblance of certain cestodes and cysticerci, and in 1782 Goeze united the two groups, but this procedure was not accepted by later authors for more than half a century. The origin of these parasites was universally attributed to spontaneous generation, the tapeworm being said to originate from the inner wall of the canal, from surplus food of a thick character like milk or cheese, or from febrile mucous secretions, while the cysticerci were gener- ally regarded as tumors (hydatids). This belief lasted long, even after the discovery of the eggs in many species. Linnzeus was responsible for propagating an- other serious error, that the cestodes were free living as well as parasitic; and this was not finally refuted until the end of the eighteenth century. It was Zeder who in 1800 first divided the parasitic worms into five classes to which Rudolphi in 1804 gave the Greek names, Nema- toidea, Acanthocephala, Trematoda, Cestoidea, Cystica, which they still bear. Of the last two, the tapeworms and bladder worms, Kiichenmeister was able to prove about the middle of the century by feeding experiments that the latter were only developmental stages of the former, thus incorporating both in the group of cestodes. Among these those forms with only a single segment may be distinguished as the Cestodaria from the Cestoda 8. str., in which group are included the large majority of the tapeworms, and all of the forms reported from man. The latter may be arranged according to the following scheme which adopts the system proposed by Braun. The groups omitted here contain no forms recorded as human parasites. Annotation is made of the stage in which each species is a human parasite and of those forms thus far recorded in this country: Order Cyclophyllidea. Family Tzeniade. Tenia saginata. Adult in man. We S.A, africana. ‘* solium. st st UW. Sa A. *“ confusa. a > U.S. A; “serrata. Larva in man (?) ““ marginata. oe 2) US. As ** echinococcus. “ S WI8Ae Davainea madagascariensis. Adult in man. Hymenolepis nana. U.S. A. diminuta. a He .S. A. (?) Dipylidium caninum. S Order Pseudophyllidea. Family B thriocephalide. Dibothriocephalus latus. cordatus. Dibothrium Mansoni. Larva in man. Diplogonoporus grandis. Adult “te KEY TO ADULT TAPEWORMS OF MAN. Scolex with four circular suckers; proglottides with marginal genital pore and without uterine orifice. Cyclophyllidea—Teeniadze. (A.) Scolex with two longitudinal sucking grooves; proglottides with superficial genital pore and with special uterine orifice. Pseudophyllidea—Bothriocephalide, _(B.) (A.) Large forms; uterus in ripe proglottides with median longi- tudinal trunk and numerous lateral branches; eggs with thin outer and thick inner shell Eepabryopnore). a.) Adult in man. U.S. A. (?) (a.) Head unarmed with small apical fifth sucker. Ripe proglottis 12 to 19 mm. long by 5 to 7 mm. wide: uterus with 20 to 30 slender lateral branches. Tceenia saginata. Ripe proglottis 7 mm. long by 12 to 15 mm. broad ; uterus with 15 to 24 simple radiating branches. Tenia africana. (aa.) Head armed with circlet of hooks. Ripe proglottides 10 to 12 mm. long by 5 mm. wide; - uterus with 7 to 10 thick branches; ovary on pore side divided by vagina. Tcenia solium. (aaa.) Head unknown. Ripe proglottides 27 to 35mm. long by 3.5 to 5 mm. ‘wide; uterus with 14 to 18 heavy irregular forked branches. Toenia confusa. (AA.) Small forms; eggs with thin transparent shells, in ripe pro- glottides grouped in capsules or irregularly ated ute (b.) Genital pores unilateral. Ripe proglottides broadly elliptical, 2 mm. long by 1.4 mm. wide. Davainea madagascariensis. Ripe proglottides trapezoidal, 0.14 to 0.30 mm. long by 0.4 to 0.9 mm. wide. Hymenolepis nana. Ripe proglottides trapezoidal, 0.75 mm. long by 2.5 mm. wide. Hymenolepis diminuta. (bb.) Genital pores on both margins of each proglottis; genital organs also double. Ripe proglottides elliptical. Dipylidiwm caninum. (B.) Genital organs single in each proglottis. Head elongated oval; length of worm 2 to 7 meters. Ripe proglottides 2 to 4 mm. long by 10 to 12 mm. wide. Dibothriocephalus latus. Head short, cordiform ; length of worm hardly over 1 meter. Ripe proglottides approximately 5 to 6 mm. square. Dibothriocephatus cordatus. (BB.) Genital organs double in each proglottis. Head not known ; length about 10 meters. Ripe proglottides 0.5 to 0.8 mm. long, 10 to 15 mm. wide. Diplogonoporus grandis. In all cases reference should be made to the fuller de- scriptions given for each species in the text, and thus the results obtained by use of the brief criteria contained in the key controlled. Especial attention should be paid to those species which are as yet incompletely known; the writer will be glad to assist in the identification of any such. The Cyclophyllidea possess a scolex with four circular suckers, often with an apical rostellum on which hooks are found when present. Segmentation is pronounced and the ripe proglottides do not separate until fully developed. There is no uterine aperture and the common sexual pore is located on the margin of the proglottides. The eggs are thin shelled and without a cover. The adults lie in the alimentary canal of the higher vertebrates. The order contains but a single family, the Tzeni- adee. For the genus Taenia the following characteristics are diagnostic. Large species with ripe proglottides much longer than broad. Uterus with me- dian trunk and subsequently formed lateral branches during the develop- ment of which the remaining sexual organs disappear save cirrus and va- gina. Larva, a cysticercus, ccenurus, or echinococcus, found in herbivorous mammals and also in man; adult in man and the carnivorous mammals, TANIA SAGINATA Goeze.—T. inermis Brera, T. den- tata Nicholai, T. lata Pruner, T. mediocanellata Kiich- enmeister, T. tropica Moq. -Tand.* Length 4 to 8 meters or even to 74 meters (Bérenger- Féraud). Head (Fig. 1215) somewhat four-sided, 1.5 to 2: mm. in diameter, without rostellum and circle of hooks but with a sucker-like depression in its place which is often pigmented. Neck long, narrower than head. Pro- glottides number more than 1,000 and increase gradually in length until the ripe segments of characteristic pumpkin-seed appearance measure 16 to 20 mm. long by 4to 7mm. broad. Gen- ital pores irregularly al- ternating, marginal, and posterior to the centre of the proglottis. Uterus in ripe proglottis with me- dian stem and twenty to thirty-five slender lateral branches, themselves often branched. Egg shell deli- cate with one or two polar filaments (Fig. 1216), em- bryophore ovoid 35 to 40 z by 20 to 80 @ in diameter. Adult exclusively in small intestine of man; larva (Cysticercus, bovis) in the muscles and viscera of cattle. Structure.—The arrangement of the reproductive or- gans in a sexually mature proglottis (Fig. 1205) is best Fic. 1215.—Anterior End of Tania saginata, Some- what Contracted. Me Se GALL er Leuckart.) Fig. 1216.—Uterine Egg of Tenia saginata Showing Shell with Polar Filaments and in the Centre Onchosphere within the Embryo- phore. X 375. (After Leuckart.) * Only the synonyms most frequently met are given under each species. 53 783 Cestoda. Cestoda. visible in a segment taken about 40 to 50 cm. from the head. The general structure of these organs has been described above. Characteristic for this species are the two ovaries of unequal size, that at the pore side being the smaller and without the small accessory lobe cut off by the vagina as in 7’ solium. The whole proglottis has a more open aspect, and the various organs show relatively greater antero-posterior diameter than in 7’ solium. The uterus in the ripe proglottis (Fig. 1207) manifests a more crowded structure, the lateral branches are slenderer. and more numerous, and two or three are stunted or lacking opposite the sexual pore. Development.—In 1861 Leuckart fed ripe proglottides of this species to calves and succeeded in obtaining the then unknown cysticercus, although various facts had pointed out cattle as the probable intermediate host. These results have been confirmed by many other in- vestigators. At six weeks the size of the cysticercus (Fig. 1211), shelled out from its cyst, is: length 3 mm., breadth 5 mm., diameter of the head 1 mm.; at twelve weeks corresponding measurements are 4, 4, 1.8 mm. (length of head); at twenty-four weeks, 6, 4, 2 mm.; at forty-eight weeks 7, 5, 2.6mm. The length of life of the cysticerci is brief; at less than eight months they have been found completely calcified. A temperature of 47° to 48° C. is always fatal. Of course the internal portions of roasting pieces are often far from reaching this tempera- ture. On the other hand exposure to cold-storage con- ditions for three weeks is sufficient to destroy all these cysticerci contained in a piece of beef. Artificial infection of man with the adult by eating flesh containing living specimens of Cysticercus bovis has been tried with equal success. An average growth of 72 mm., or about thirteen to fourteen proglottides daily, was determined. Anomalies.—T. saginata appears to be peculiarly sub- ject to variation and malformation. Excessive pig- mentation of the head and chain led to the establishment of the species 7. nigra Laboulbéne (1875) for a tapeworm expelled by a Frenchman who had lived for some time in the United States. Two genital pores, on the same or opposite margins of the proglottis, but each connected with a set of reproductive organs, indicates the probable disappearance of the segmental boundaries, and this may be manifested over a considerable stretch of the worm, giving the appearance of an unsegmented body. Welch has observed such an unsegmented region 5 cm. in length. Intercalated proglottides or roughly triangular joints are not of infrequent occur- rence. A common malformation consists in the perforation of a series of proglottides. This anomaly has received a specific name, 7. fenes- trata, at the hands of one observer. The fenestration appears first at the centre of the proglottis and be- comes more accentuated toward the posterior end of the chain. Its cause is not understood. Finally there occurs a prismatic or triradial variety (Fig. 1217) which 05 was described by Bremser as the result of the fusion of two individu- als. The proglottis is Y-shaped in cross section, and the scolex bears six acetabula. Specimens of this sort were named 7. capensis by Kiichenmeister and 7. lophosoma by Cobbold. Onchospheres of 7. saginata have been observed of considerable size, and armed with from twelve to twenty-two hooks; and Cobbold has described specimens of Cysticercus bovis from the heart of a calf with only three, two, one, and even no suckers on the head. : The form described by Weinland as 7. soliwm var. abietina, from a specimen collected by Agassiz from a Fic. 1217.— Portion of the Chain from Pris- matic Specimen of Tenia saginata, Showing also the Oc- casional Separation of the Three Wings for a Short Distance. 0s, Sexual Pore. Natural size. (After Cattaert.) 784 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chippewa Indian, is regarded by many as a small speci- men of 7. saginata with unusually dense and delicate branches of the uterus (Fig. 1218). Distribution.—The adult occurs only in man and is cosmopolitan. Its presence in the Orient is recorded in writings of great antiquity; in Africa, Europe, and America it is also abundant, and its frequence has in- creased during recent years, whereas the contrary is true of 7. soliwm. The evi- dent reason lies in the custom of eating beef rare, but pork well done. The fig- ures given by Bérenger-Féraud for French maritime hospitals during the six quinquennial periods from 1861 to 1890 show a steady relative increase of cases from 0.2 to 14.8 per mille. In Paris the increase, though real, was much less, being from 0.3 to 0.6 per cent. in the same time. The larval form, C. bovis, has been produced experimentally in rare in- stances in other hosts, sheep and goat, but many experiments on these and other hosts have been entirely without results. In its normal host (cattle) the bladder worm was apparently rare, even in regions where 7. saginate occurred abundantly. This apparent contra- diction has been explained by the demonstration that in most cases normal infection is only mild and the cysti- cerci are so small and scattered as not to be easily found in the beef. Their predilection recently discovered for the pterygoid muscles affords, however, a surer means of diagnosis now than was formerly known. A limited number of observations on the presence of C. bovis in man are on record, They include cases from the brain and eye, and the determination of the species rests on the absence of hooks and rostellum. Since, however, these organs may be wanting in C. cellulose, the larva of 7. soliwm (q. v.), the determination in the cases under discussion must be viewed with suspicion. Pathology.—Most common in hosts between twenty and forty years of age, the beef tapeworm has been encoun- tered in the aged and even in newborn infants. Its normal place of fixation is near the pylorus, where the head is firmly fastened to the mucosa by its suckers. It may, however, be found exceptionally in the stomach. Symp- toms of its presence are direct and local in the digestive system, or nervous-and reflex in character. The latter are rarer but may be severe. A. Stieda has recently de- scribed a case in which this species, in spite of its lack of hooks, had bored through the wall of the duodenum and some distance in a circuitous course into the pancreas. In this case there were neither abcesses nor preformed orifices of which the worm could have made use, while other evidence supported the view of active burrowing on its part. Possibly the rare cases in which tapeworms have made their exit through the navel or bladder may be susceptible of a similar explanation. This is, how- ever, the only case on record which has been subjected to a thorough scientific investigation. The proglottides of this species are expelled spontane- ously and in the interval between stools. The move- ments after expulsion are active and long continued as is evinced by the discovery of segments high on the walls of sick-room or outhouses. The anterior margin is lacer- ated by separation from the chain, and in crawling the proglottis distributes eggs from the uterine branches. These detached segments are frequently diagnosed as flukes, a conclusion apparently strongly confirmed by their independent activity. This species cannot be regarded as equally dangerous with 7. solium since here there is no chance for auto-infec- tion by the onchospheres. The disturbances attending its presence in the alimentary canal, however, are such as to call for its removal. Despite the absence of hooks in the species this is, as a rule, more difficult of accomplish- ment than in the case of the pork tapeworm. The re- moval of the body without the head and neck constitutes Fic. 1218.—Ripe Proglottis of Tenia solium (= T. saginata var.) var. abie- tina Weinland. (After Wein- land.) REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Cestoda, Cestoda, but a temporary relief since a new chain is produced in a short time. TANIA AFRICANA Vv. Linstow 1900.—Length 1.4 me- ters, greatest breadth 12 to 15 mm, Scolex unarmed, no- aot < — 6 ELY.Os ahaeigare te tetenumale tetera ewe i 5 ae 1 Pericardignie..sopemachi skiers 1 : al OVATICSAc5.N ee oonwce cale von ee is il x aah 1 Wlerushkincantns venience tin 3 ne 3 Trinkets reac fevers einesinreiets i 0 4 4 KiGMCYS <5 shicsac’s gsi con eieteleis @eieis re 3 Si 123 126 Neck (fascia) ........ eta cele luacare a AG Rete af RlOMACH, cose te auc utteentc seenes al i 5 2 Extensors Of thigh.)c, +s. sssie a6 1 aa 1 PICULAveeiatettsies = Gelsine eee ene ae 1 We 19 20 Circulatory apparatus ........... af an 53 53 CranialiGAvit¥2., cic teccnnteantsaces ae ne 91 91 Spinal canal..... i Wacascetetente te ein ii, Bie 13 13 PelVIS Manabasee sta cu weuse caret 3 2 70 75 Peritoneum and omentum....... 1 ; 61 62 Mesentery and omentum ........ 1 A i Female genital organs and mam- WHOTIOS paeincnc Wis ehaintisalee tener ae Ab 60 60 Male genital orgams.............. ie ate 9 9 Face, orbit, and mouth.......... on ae 41 41 IN@CK crite Bidens otaittumeal ott a iyakisre ee ae 18 18 ‘ADGOMED! aan sais vel weles sways alstoret 2 Ay 80. a, Isolated hook. x 480. (After Leuckart.) Fig. 1237.—Ante rior End of Hymeno- lepis diminuta. Magnified. (After Zschokke.) (Letters as before.) Magnified. Co Cestoda, Cestoda, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Diryurp1um R. Leuckart 1863.— Rostellum retractible, armed with several annular rows of alternating hooks. Genital pores opposite, organs doubled. Uterus at first a reticulum, which later becomes changed- into sacs holding. one or more eggs each. Eggs with double shell. DIPYLIDIUM CANINUM Railliet 1893; T. moniliformis Pallas, 7. cwewmerina Bloch, 7. elliptica Batsch.—Length 10 to 40 cm., greatest width 1.5 to 8 mm. Scolex (Fig. 1239) small with retractile claviform rostellum armed with three or four rows of thorn- shaped hooks which decrease in size from 15 in the first row to 6 win the last; suckers elliptical, neck short. First proglottides small, becoming trapezoidal and finally characteris- tically of melon-seed form. Eggs spherical, 43-50 « in diameter; oncho- sphere, 82 to 86 “ in diam- eter. Adult parasitic in the small intestine of the dog, cat, and rarely also 3 man; larva (cryptocystis) =. in the body cavity of the dog flea and dog louse. The most striking fea- ture of the structure of this species is the doubling of the reproductive organs, a complete set with genital pores and copu- latory organs being present on each side of the proglottis (Fig. 1240). The branches of the uterus, however, become cut off as small capsules containing eight to twelve eggs each; in the ripe proglottis the mass of such capsules fills the entire middle field, and a reddish-brown substance deposited around the eggs imparts a charac- teristic pink color to these segments. Prismatic and fenestrated specimens have been observed, and also in- dividuals in which four sets of organs lay in a single proglottis. The onchosphere is transformed in the body cavity of the dog flea, or even of the human flea, into a tailed larva, or cryptocystis. When the dogs, annoyed by the work of the fleas, hunt out and destroy these pests, it is easy to see how they infect themselves. With a single exception all recorded cases of this tape- worm in man are among children who have by some Fig. 1239.—Anterior End of Dipylidiwm caninum. (Orig- inal.) Bhi s Voyat i, ‘6.Nn. Fig. 1240.—Median Portion of Sexually Mature Proglottis of Dipylid- ium caninum; ¢, cirrus; ov, ovary; 7s, seminal receptacle; t, testis; uw, uterus; v, vagina; vt, vitellarium. X 25. (From Railliet, after Neumann.) chance obtained the larva of the parasite from playing withdogs. The first case on record dates from Linneus, and other cases have been reported from England, Ger- 792 many, France, Russia, and Scandinavia. Judging from the frequence of the parasite in dogs in this country, similar cases should not be rare here. I have found none definitely recorded. The order Pseudophyllidea is characterized by the pres- ence on the scolex of two poorly developed sucking grooves which may be in some cases much modified. Of the three sexual pores the uterine orifice lies always on one surface of the proglottis, whereas the two others may be on the same or opposite surface, or on the margin of the proglottis. The sexual organs are generally single, rarely doubled; their development does not transcend the stage of maturity so that no parts degenerate. Eggs usually with cover. Among the twenty-one genera known, only two are of immediate importance here. DrIBoTHRIOCEPHALUS Liihe.—Scolex elongated; suck- ers not powerfully developed; genital organs single; genital pores ventral; uterusin coils in centre of the pro- glottis producing a characteristic rosette figure (Fig. 1241). BSerooeten LATus Lithe 1899; Tania lata Fig. 1241.—Ventral Aspect of Sexually Mature Proglottis of Dibothriocephalus se oe Female Reproductive Organs. 1206.) xX 12. (After Leuckart. (Cf. Fig. and 7. vulgaris L. 1748; Bothriocephalus latus Bremser 1819; Dibothriwm latum Dies 1850. Length, 2-9 meters, rarely up to 20 meters, grayish yellow; head elongated oval, 2-8 mm. long, 0.7-1 mm. broad, transversed by two deep lateral grooves. Proglottides, three thousand to four thousand in number, usually broader than long but becoming gradually quadratic. All sexual pores on mid-ventral line, cirrus and vagina opening close together and in front of uterus. Eggs, 68-70 4 by 45 uw. Adult parasitic in small intestine of man, dog, and cat; larva (plerocercoid) in the muscles and among the viscera of various fish. Structure.—The longitudinal sucking grooves, charac- teristic of these forms, occupy in reality the upper and lower face of the head, appearing at the sides in con- sequence of the torsion of the neck. In external appear- ance the chain is clearly distinguishable from the other large human tapeworms, 7. saginata and 7. soliwm, by its greater thickness at the middle of the segment. The arrangement of the sexual organs in the proglottis (Fig. 1206) also differs radically from that already described in the genus Zenia. The numerous testes occupy a lateral position in the medullary region of the segment, and the vas deferens extends in loops toward the anterior end, terminating in a muscular cirrus pouch with a seminal vesicle. Next the male genital pore lies the orifice of the vagina which passes directly posteriad in the median line, and after forming a receptaculum seminis joins the common yolk duct near the centre of the voluminous shell gland. The vitellaria or yolk glands are racemose structures occupying the cortical layer of the segment in the lateral fields; their numerous ducts converge and ultimately unite into the common yolk duct noted above. The paired ovaries lie one on either side of the shell gland in the posterior region of the proglottis, and the oviduct joins the vagina and the yolk duct in the shell gland. From the union of these ducts originates a canal which expands, and as the uterus, lying in irregular loops ven- tral to the vas deferens, extends forward to the special uterine orifice, a simple pore in the mid-ventral line a REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. short distance behind the common opening of the cirrus and vagina. In the last proglottides the uterus is often empty of eggs and the genital glands are atrophied. Development.—Ripe proglottides contain numbers of brownish, elliptical eggs in which may be distinguished the egg cell surrounded by masses of A, yolk cells. After lying in water sev- * eral weeks a ciliated onchosphere (Fig. 1209) is hatched out and swims about in the surrounding water. Sometimes ) this embryo throws off the ciliary cov- ering, but ultimately dies without at- taining any further development. How the onchosphere is transformed into a plerocercoid remains still undiscovered. Braun was inclined to believe in the necessity of another intermediate host, and Leuckart and others have endeav- ored in vain to infect directly with onchospheres the various fish which harbor the larval form. The bladder worm of Dibothriocephalus latus was first discovered by Braun in the mus- cles and viscera of food fish in the Baltic provinces. It is an elongated form known as a plerocercoid (Fig. 1242), and measures 8-30 mm. in length. These larve were abundant in fresh fish from Dorpat markets, and living specimens were also obtained from smoked, salted, and frozen fish as well as in the roes of the pike, which salted are eaten raw as caviar. Experi- mentation on dogs, cats, and man established the con- nection of this larva with the adult Dibothriocephalus latus. Other authors, notably Zschokke in Switzerland (Geneva), have discovered the larve in perch, salmon, trout, grayling, and whitefish, and in some instances have determined experimentally their relation to the species of cestode under consideration, confirming fully the discoveries of Braun. In Scandinavia, Lombardy, Switzerland, and Japan the existence of the plerocercoid in various fishes and the consumption of some part of the latter in a raw condition by the native population ex- plain the method of human infection which has been further determined experimentally in specific cases. Once introduced into the human alimentary canal the development of this tapeworm is very rapid, being from 5 to 9 cm. per day in the various cases. Eggs ap- pear in the feeces of man in from twenty-four to thirty days after infection. Anomalies.—Slender specimens (var. tenella) have been recorded, as also some with exceptionally large proglot- tides. One specimen of the prismatic variety is on record (of. T. saginata) and fenestration of greater or less ex- tent is not rare. Most frequent, however, is the redupli- cation of the genital pores and organs which Leuckart says he has never failed to find in some proglottis of each specimenexamined. Undera separate name (Bothrioceph- alus cristatus) Davaine described a variety which is dis- tinguished from the common by possessing a projecting longitudinal ridge on each flat surface of the head. Geographical Distribution.—The peculiarities in the distribution of this species are intelligible in the light, of its development. It is abundant on the shores of the Baltic, especially the Russian and east Prussian, and around the lakes of French Switzerland, while the terri- tory adjacent to these regions furnishes sporadic cases varying greatly infrequence. Small centres, like Munich (Bavaria), are known to exist, where the origin of the parasite has been attributed to the fish of a certain lake or lake region. In Africaanew centre has been reported recently in the territory around Lake N’gami. In Japan this form is the most abundant of human and canine parasites. Its presence in other regions than those noted has been recorded occasionally, and usually in per- sons known to have come from the infected regions. Of this type is the record of its presence in Philadelphia made by Leidy. According to Zschokke this species is becoming rarer in Geneva, its frequency having fallen Fig. 1242.—P lero- eercoids of Di- bothriocepha lus latus from Pike. A, Natural size; B, C, with scolex protruded and re- tracted. X2. (After Leuckart.) ‘following species of which the Cestoda, Cestoda, in thirty years from ten to one per cent., and in Paris where it was abundant in the eighteenth century it is no longer autochthonous. Pathology.—It is sometimes solitary, though several in- dividuals occur together in the majority of cases and nearly one hundred have been recorded from a single host. Evidently its frequence depends upon the habits of the individual in eating raw or poorly cooked fish no less than upon the locality. The effect of the parasite is often unnoticed; in other cases are noted gastric and nervous disturbances, and even pernicious anemia, which disappear with the removal of the worm. These troubles have been attributed to the production of some toxic substance by the parasite. It should be noted that a self- infection is impossible. DIBOTHRIOCEPHALUS CORDATUS (Leuckart 1862),— Length, 80 to 115 cm. Head (Fig. 1243), 2 mm. in di- ameter, flattened cordiform, with deep bothridia on ven- tral and dorsal surfaces. Segmentation begins directly behind the head; the proglottides, which increase rapidly in width, become mature within 3 cm. The largest proglottides measure 7-8 mm. in length by 3-4 mm. in breadth and number about six hundred. Eggs, with cover, measure 75 « by 50 uw. Adult parasitic in seal, wal- rus, dog, and man in Greenland; larva unknown. The adult is a common parasite in its native land, but records of its presence outside of Greenland are based on errors. However, sporadic cases may occur in those who have become infected while visiting its native home. The intermediate host is doubtless a fish. DrsotHrium Mansont Ariola 1900. Ligula Mansoni Cobbold; Bothriocephalus liguloides Leuckart.; B. Man- sont R. Bl.—Adult unknown. Larva a plerocercoid; length, 12 to 20 or even to 85 cm.; breadth, 8-6-12 mm. ; flattened without proglottides, but marked by irregular folds. Anterior end enlarged, bearing the head which may be drawn in or evaginated, and on which two faint both- ridia are visible. Parasitic in connective tissue of man in Japan and China. Ten cases of the occurrence of this parasite are re- ported, one from China and the rest from Japan. It was first found by Manson in an autopsy when a dozen specimens were taken from below the peritoneum, and one free in the peritoneal cavity. IJjima and Murata have described in detail seven cases from Japan; in three the parasite was passed with urine or taken from the urethra, in three cases also it was drawn from tumors of the eye, and in one from a cavity in the subcutaneous connective tissue of the thigh. Doubtless the larva wanders about in the body of its host, in which, as appears from the details of the last case cited, it may remain active as long as nine years. Ulti- mately it reaches the surface of the body or of an internal organ (bladder) from which it eventually attains the ex- terior. Of its origin or its further development nothing is known. No trace of reproductive organs could be found in the specimens studied. In its unusual size and in the presence of longitudinal grooves on the ventral surface, this larva resembles the adult alone is known. DiIPpLoGoNoPorus Lénnberg 1892; Krabba R. Blanchard 1894.—Genital organs doubled in each proglottis; in other respects identical with those of Débothrio- cephalus. Genital orifices of each set ventral on either side of the median line of the body, but in of cian Fi | Fic. 1243.—Anterior End Dibothriocephalus 2 F ae s cordatus in Lateral the median line of either uterine nq gurface_ Views. field. _ x65, (After Leuckart.) DIPLOGONOPORUS GRANDIS Lithe 1899; Krabbea grandis R. Blanchard.—Length, 10 meters or more; maximum breadth at anterior end 1.5 mm., in broadest region 25 mm. Proglottides very short, near posterior end only 0.45 mm. in length by 14 to 16 mm. in breadth. Scolex unknown. Genital organs double; two lateral rows of sexual openings on the ventral sur- 793 Chalybeate Springs. Chancroid. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. face, located in longitudinal grooves with genital sinus in front and orifice of uterus behind it. Eggs brown, Found in thick shelled, 63 ~ by 48 to 50 ~ in diameter. Fic. 1244.—Sinistral Set of Reproductive Organs from Sexually Mature Proglottis of Diplogonoporus grandis. xX 140. (After Ijima and Kurimoto.) man in Japan; larva unknown. The first account of this remarkable species was given by Ijima and Kurimoto. It is unique not only in the extreme size manifested, but also in the double genital apparatus which occurs in some species from seals, but save for this species is un- known among human parasites of this group. The sex- ual organs (Fig. 1244) are characteristically bothrioceph- aline, but they are found in double sets right and left in each segment, and the orifices open at the bottom of two longitudinal grooves which are characteristic fea- tures in the appearance of the worm (Fig. 1245). The authors report that the patient had suffered for five years from diz- ziness and colic which had finally be- come so severe as to call for his ad- mission to the hospital at Nagasaki. Here the parasite was removed and even on the following day all the trouble of long standing had entirely disappeared. In view of our rapidly growing intercourse with the East this should be looked for among the un- welcome additions which are sure to be made to our helminthological fauna. Quite recently Kurimoto has given an account of a second case (also from Japan) in which two specimens of the same parasite were passed. Unfor- tunately, both scolices were wanting here also. In other particulars the agreement with the original specimen of this species was complete. Anomalies such as fenes- tration, intercalated proglottides, and those of asymmet- rical form were frequent. Henry B. Ward. Fig. 1245.—- Ventral View of Portion of Chain from Di- plogonoporus grandis. a, Ven- tral groove. Nat- ural size. (After Ijima and Kuri- moto.) BIBLIOGRAPHY. Blanchard, R.: Histoire zoologique et médicale des téniadés du genre a pmenolepis Weinland. Bibliothéque générale de Médecine, Paris, Braun, M.: Cestodes. Bronn’s Klassen und Ordnungen des Thier- reiches, Bd. iv., Abt. i., 1894-1900. Die thierischen Parasiten des Menschen. Wiirzburg, 1895. Goldschmidt, R.: Zur Entwicklungsgeschichte der Echinococcus- AU ie Zool. Jahrb., Abt. Anat., Bd. xiii., pp. 467-494, pl. x xxiii. Guyer, M. F.: On the Structure of Tzenia confusa Ward. Zool. Jahrb., Abth. Syst., Bd. xi., pp. 469-492, pl. xxviii. Huber, J. C.: Bibliographie d. klinischen Helminthologie. Hefte 3, 4. Miinchen, 1892. Tjima, I.: The Source of Bothriocephatus latus in Japan. Jour. Coll. Sci. Jap., vol. ii., pp. 49-56, 1888. Tjima, I. and Kurimoto, T.: On a New Human Tapeworm (Bothrio- Neto sp.). Jour. Coll. Sci. Jap., vol. vi., p. 371-385, pl. xviii., 8 Ijima, I. and Murata, K.: Some New Cases of the Occurrence of Both- riocephalus liguloides Lkt. Jour. Coll. Sci. Jap., vol. ii., pp. 149- 162, pl. v., 1888 Krabbe, H.: Forekomsten af Bandelorme hos Mennesket I Danmark. Nord. Med. Arkiv., No. 19, 12 pp., 1896. Kratter, J. and Bohmig, L.: Ein freier Gehirncysticercus als Ursache plétzlichen Todes. Beitr. pathol. Anat. u. allg. Pathol., Bd. xxi., pp. 25-42, 1 plate, 1897. 794 Kurimoto, T.: Beschreibung einer zum ersten Male im menschlichen Darm gefundenen Art von Bothriocephalus. Zeitsch. f. klin. Med., Bd. xl., pp. 16, 2 plates, 1900. \ Liihe, M.: Zur Anatomie und Systematik der Bothriocephaliden. Verhandl. Deutsch. Zool. Ges., pp. 80-55, 1899. Limstow, O. v.: Tenia africana. Centralbl. Bakt. u. Parasit., Abt. i., Bd. xxviii., pp. 485-490, 2 figures, 1900. Leuckart : Die Parasiten des Menschen, etc., 2 Aufi., Leipzig, 1879-86. Neumann, L. G.: A Treatise on Parasites and Parasitic Diseases of the Domesticated Animals. Translation by Fleming, London, 1892. Nuttall, G. H. F.: The Poisons Given Off by Parasitic Worms in Man and Animals. Am. Nat., vol. xxxiii., pp. 247-49, 1899. Seat A.: Traité de zoologie médicale et agricole. 2. Ed. Paris, 893-95. Sommers, H. O.: Further Statistics on Echinococcus Disease in the United States. N. Y. Med. Jour., vol. Lxiv., pp. 263-265, 1896. Stiles, C. W. and Hassall, Albert: The Inspection of Meats for Animal Parasites. U.S. Dept. Agr. Bureau Animal Industry, Bull. 19, 1898. Stieda, A.: Durchborung des Duodenums und des Pankreas durch eine bhp Centralbl. f. Bakt. u. Par., Abt. i., Bd. xxviii., pp. 430-437, Verdun, P. et Iversenc: Note sur un cas de cysticerque du ventricule latéral gauche. Arch. Parasitol., T. i., pp. 9, 2 figures, 1898. Ward, H. B.: The Parasitic Worms of Man and the Domestic Animals, Report Neb. Bd. Agr., pp. 225-348, 1895. A New Human Tapeworm (Tenia confusa). West. Med. Rev., vol. i., pp. 35-36, 1896. Note on Tonia confusa. Zool. Anzeiger, Bd. xx., pp. 321-322, 1897. Weinland, D. F.: Human Cestoides; An Essay on the Tapeworms of Man. Cambridge, 1858. Zschokke, F.: Recherches sur la structure anatomique et histologique des Cestodes. Trav. couronné, Genéve, 1888. Also numerous shorter papers by the same and other authors. CHALYBEATE SPRINGS. — Meriweather County, Georgia. Post-OFrFrice.—Chalybeate Springs. tages. Accrss.—Take Southeastern Railroad to Bostwick, thence Talbottom Branch Road to Talbottom, thence 20 miles west to Springs. These springs were discovered by Mr. Rawlings about 1835, and opened by him for the reception of visitors a few years later. The improvements were of a rude char- acter until about 1850, at which time they were consider- ably enlarged. With the exception of a few years’ in- terval they have been open to the public ever since. Analysis by Prof. W. J. Land: ONE UNITED STATES GALLON CONTAINS: Hotels and cot- Solids. Grains. Silicic acid: (SOlmDE) ii cesiem saalaniaetiantete a ieca. plover eralaketats teres 2.83 TFON PLOLO-CALOOMALC. ciasciere sist wisls\ola'e vietsin iets) yeints etree : 62 Iron sesqui-carbonate... te el Lime Carbonate:iccicciaas obs ctsecctis ce siete sulere esis recente 76 Potassium: SUIPNHAtTE. o0..0 602 vsckssiecs cicwices ¢erecechiietne 33 Sodium: sulphates. vases eeee nee nin. oeempeeeaies cmele Aluminum sul phates, ¢oojs.003 «2.0 <0 csicieis ses lees ala meteneenete ones case BodIUM: CHIOTIGG <0 0.0.0 c'si00 0 s0'e.'e aioe cle esn'e cleie\cistele diate a ieee -03 OGG Sv ciare's 0:0: e1e giaye. © Sisle's. 01mm eeie tte ecelevo/etialsieaiere a Tear eeatanatE 5.30 Carbonic acid gas, 6.55 cubic inches. The water is a light chalybeate. There are also traces of hydrogen sulphide, carbonate of magnesia, crenate of iron, and a minute trace of nitric acid, lithium, and or- ganic matter. The proportion of soluble salicylic acid is larger than usual. This compound is not used in medi- cine, but silica is contained in the human body, and may not be without therapeutical value. It is possible that the trace of sulphureted hydrogen also slightly influences the action of the water. It has been recommended in all cases requiring a chalybeate water. The flow is abun- dant, being about twenty-five gallons per minute. Near by is a sulphur and magnesia spring, but no analysis has been made of the waters. The improvements are exten- sive, consisting of two hotels and cottages, sufficient to accommodate five hundred guests. Bathing facilities are ample, both hot and cold water being supplied. The cli- mate of this region is of a salubrious character. James K. Crook. CHAMA-LIRIUM. See Unicorn Root, False. CHAMIQUEL.—Coalcoman, Michoacan, Mexico. A lukewarm mineral water classified by Dr. Zuniger as a sulphureted calcic water, and containing, according to Forbes, of Coalcoman, carbonic acid, large quantities of lime and magnesia, silica, and traces of copper and iron. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chalybeate Springs, Chancroid, No bathing facilities have been established so far. The bathers are recruited from among those suffering from leprosy and diseases of the skin. V. J. Ponce de Léon. CHAMOMILE.—ANTHEMIS. Roman Chamomile. “The flower-heads of Anthemis nobilis L. (fam. Composi- te), collected from cultivated plants” (U.S. P.). In this definition the Pharmacopceia recognizes the fact that un- der cultivation the aroma and flavor of the chamomile grow finer and less rank and heavy, notwithstanding that the percentage of volatile oil, and very likely the medicinal] strength, are somewhat decreased. The chamomile plant is a native of Europe and is largely cultivated in temperate regions. It is a low perennial, hairy herb with a Sic branching rhizome, and rather ZAK “O\ Sige numerous stems, most of which Ah CAISS are short and bear leaves only. The flowering stems are long, slender, prostrate, often root- ing at the base, but ascending and branched above, and _ bear- ing the flowers at the ends of the branches. Flower-heads ra- diate, about 2 cm. (#1n.) across, with, in the “single” (natural) form, a single row of white rays and a yellow disc. Invo- lucre of two or three rows of blunt, appressed, scarious-mar- gined scales. Receptacle chaffy, conical, solid, longer than broad; ray flowers fer- tile, limb three-toothed; disc flowers perfect, tubular below, bell-shaped above. Achenia obovate, slightly compressed, pappus none. The oil glands , are mostly on the corolla tubes, =k: and less abundant on the ray \ than on the disc flowers. The plant is a native of Europe, and is largely culti- vated in temperate regions. Under cultivation, ligulate flowers largely replace the tu- bular disc flowers, so that the heads become “double” and large and white, which condition, by careful and rapid drying, should be preserved in the dried heads. Chamomile contains nearly one per cent. of a blue vola- tile oil, turning greenish or yellowish with keeping and having a specific gravity of .905 to .915. The important constituents of this oil are anthemol (C:oHi.O) and cumin aldehyde (Cy>H,1,C3;H;,CHO). The composition of the re- mainder of the oil is very,complex. With the oil there are an amaroid, some resin, and a little tannin. Chamomile is one of the very best of the aromatic bit- ters, and is strongly carminative and somewhat antispas- modic. The dose is 1 to4 gm.(34toi.). There is no official preparation. The best form of administration is a tincture, so as to contain all the oil. Asa simple stom- achic a decoction or infusion is excellent. This should be well diluted, taken slowly before meals, and the dose should be small. The oil is often given as a carminative and antispasmodic, in doses of M™ i. to v. Atiinp PLaAntTs.—The genus contains about eighty species, and includes the common mayweed (Anthemis cotula Linn.). They are generally less agreeable than chamomile, and although of similar qualities, not in use. Chrysanthemum parthenium Pers. (Feverfew) is some- times used as a substitute or adulterant of this article. It can be told by its flatter and less chaffy receptacles. Henry H. Rusby. CHAMOMILE, GERMAN.—MATRICARIA. “The flower-heads of Matricaria Chamomila L. (fam. Composi- te)” (U. 8. P.). This drug is the product of a daisy-like plant, one to two feet in height, native of Europe and Fig. 1246.—Chamomile, Wild or Single-Flowered Plant. One-third natural size. (Baillon.) .is the pathogenic organism. Western Asia, and introduced, as a roadside weed, into many countries. The reflexed rays are about fifteen in number, nearly half an inch long, white, three-toothed. These rays, together with its elongated, conical, and hol- low receptacle, which bears no scales, distinguish it pon all drugs or substitutes which might be mistaken or it. Its active constituents are its anthemic acid, which is very bitter, and less than half of one per cent. of a dark blue volatile oil. There are also asmall amount of tannin and some anthemidin. The drug is very largely used as an ingredient of pro- prietary “teas” and other herb mixtures, but possesses only ordinary aromatic-bitter properties of the Composite, which see. The ordinary dose is 1 to 4 gm. (gr. xv. to lx.), and it is commonly given in infusion or fluid ex- tract. Henry H. Rusby. CHANCRE. See Syphilis. CHANCROID.—Chancroid is a local, contagious, vene- real disease, appearing as suppurating ulcers about the genitals, and is due to contact with secretions from the same kind of ulcerations. Aside from causing more or less severe inflammatory reaction in the lymph glands in the immediate vicinity of the sores, chancroid is always a local process and never causes constitutional infection. Until within the last half-century it was generally be- lieved that syphilis and chancroid were due to the same cause, but their individual entity has now so long been established that the old opinions interest us simply asa matter of history. The two diseases very frequently exist in the same individual at the same time, but they are, of course, due to inoculation at the same time and spot with two entirely separate and distinct poisons. At the outset too much emphasis cannot be placed on the necessity of a careful examination and accurate diag- nosis of all venereal sores. Cases of initial syphilis are constantly being diagnosed as chancroids. Many men have married with their doctor’s approval (and reassur- ance that their sore wasa soft oneand therefore harmless), only to see syphilis appear in themselves and be trans- mitted to their wives and children. To the clinical observer the purulent secretion from chancroids is the medium which conveys the contagion, and it has been claimed that the leucocytes alone contain the virus, and that inoculations with a solution from which the pus cells had been removed yielded negative results. We also know that cold has apparently little effect upon the vitality of the organism, while it is readily destroyed by heat, drying, and antiseptics. ErroLtogy.—Chancroid is undoubtedly due toa specific micro-organism, but what that organism is has not yet been conclusively demonstrated. At the present time there are only two opinions that are deserving of consideration: first, the claim that the ordinary pyogenic bacteria are capable of producing typi- cal chancroidal ulcers; second, that the bacillus of Ducrey It has also been claimed that cases of chancroid have arisen de novo, there having been no active chancroidal ulcerations present in the party giving the infection. In asserting that chancroids are of purely pyogenic origin, it has been pointed out that the secretions from chancroids always contain streptococci, staphylococci, and non-pathogenic bacilli, as well as the streptobacillus first described by Ducrey and claimed by him to be the specific organism of chancroid. It is also claimed that chancroid is to mucous membranes what impetigo and pus infection are to the skin, and that the streptobacillus is an accidental accompaniment and not the cause; and, furthermore, that chancroid is usually found in broken- down prostitutesand among the poorer classesin general, a class whose vitality is lowered by lack of proper food, over-indulgence in alcoholics, by filth and unhygienic surroundings; in other words, a class in whom we know that slight abrasions of the skin become easily infected with pus cocci, suppurate freely, and do badly in general. 795 Chancroid, Chancroid, Certainly the genitals in the uncleanly, with heat, mois- ture, and decomposing smegma, furnish an excellent medium in which the pus organisms may grow. Now it is well known that chancroid is by no means confined to the cachectic and debilitated, but may occur in the robust and healthy when exposed to chancroidal infection. If pyogenic bacteria alone were capable of causing chancroids, those individuals with long foreskins and excoriative balanitis, with acquired phimosis and a foul, subpreputial discharge, would develop chancroids. Furthermore, women with peri-urethral or vulvo-vagi- nal abscesses, complicating gonorrhcea, or men with ul- cerations dependent on scabies of the genitals, would also develop chancroids. Clinical experience shows that such is not the case. It was pointed out by Ducrey that in repeated in- oculations with chancroidal pus the accompanying streptococci, staphylococci, and other bacteria rapidly disappeared, leaving nearly pure cultures of the strepto- bacillus, which he looks upon as the pathogenic organ- ism of chancroid. Unna, Krefting, Wielander, and others have found, both in smear preparations and in sections from the floor and walls of chancroidal ulcers, these same bacilli described by Ducrey. They are short and thick, with rounded ends, and have a slight constriction in the middle which gives them a sort of figure-of-eight or dumb-bell appearance, and tend to group themselves in parallel chains. The bacilli usu- ally lie outside the cells, though occasionally within them, and they are said not to be found in the pus of suppurating chancroidal buboes. The bacilli of Ducrey stain readily with fuchsin or gentian violet, and are de- colorized by Gram’s method of staining. Bacteriological investigation is handicapped by the inability to grow the bacilli on artificial media, and also from the fact that up to the present time animals have not been successfully inoculated. Until these bacilli can be cultivated and inoculations made producing characteristic lesions, and from these lesions the organisms recovered, the claims for the Ducrey bacillus cannot be accepted as conclusive. CuinicAL Hisrory.—There is no period of incubation in chancroid. The process begins as soon as the virus gains an entrance to the tissues, and usually is noticed within two or three days after exposure. The first thing that appears is a small papule witha yellowish centre situated on an inflammatory base and surrounded by a slight halo of congestion. The yellow vesicle in the centre increases and soon ruptures, leaving a small ulcer with a grayish, velvety base and sharp. well- marked edges, giving ita punched-out appearance. The edges become undermined and give way, and the size of the ulcer increases in this manner, the surrounding con- gestion spreading as the ulceration advances. The floor of the ulcer then has a grayish, uneven, worm-eaten ap- pearance, is bathed in pus, with little tendency to bleed, unless roughly handled. There may be only one ulcer at the start, or there may be several, but soon fresh points of auto-infection appear and each new ulceration goes through the stages of destruction, rest, and repair like its predecessors. This tendency to spread by auto-inoc- ulation is one of the most striking and constant of the characteristics of chancroid. The floor and edges of a chancroidal ulcer, no matter how long it has existed, are never indurated unless it has been cauterized. Within a short time after the appearance of chancroidal ulcerations the glands in the immediate vicinity may be- come inflamed. Usually but a single gland in the chain swells, becoming both painful and tender, but the glands in both groins may become affected. Not infrequently the glands break down and require surgical care. In trying to determine the character of a doubtful sore, great care should be taken to notice the condition of the neighboring glands, for their behavior in chancroid is so entirely unlike the condition in syphilis that it is one of the chief features in diagnosis. In chancroid the glandsare either not affected at all, or when affected, are inflamed, painful, and tender, and 796 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tend to suppurate, while in syphilis the process is non- inflammatory, the glands are neither painful nor tender, and they very rarely undergo suppuration. In men with long foreskins soft chancres situated on the mucous membrane of the prepuce or along its free margin often cause an acquired phimosis with a good deal of heat, redness, swelling, and pain. The whole prepuce then feels thickened, brawny, and tender, and may entirely obscure the beginning induration of a sore beneath, so that in this condition one should be very guarded as to the outcome of such a case. When the ulcers are seated about the ostium preputii, micturition is usually painful, as the urine comes in contact with the raw surfaces. This pain may be greatly relieved by urinating with the penis immersed in warm water. It is not uncommon to find the lymphatics running along the dorsum of the penis inflamed and tender, and occasionally a gland at the base of the penis swells and may even suppurate. Location.—Chancroid is usually located about the genitals. Extra-genital chancroids do occur, but are very rare as compared with the extra-genital initial lesions of syphilis. In men the most common site of chancroids is in the sulcus, back of the corona glandis, next the frenum. Here minute tears occur from mechanical vio- lence during intercourse and are readily infected. Ulcerations in this location are more painful and tend to bleed more easily than in other spots. They also fre- quently perforate and destroy the franum entirely. The resulting ulcers are slow to heal and may give rise to a good deal of hemorrhage, owing to the abundant blood supply. Another common spot is along the free margin of the prepuce. Here the ulcers are irritated in handling the penis in urinating, in retracting the foreskin for pur- poses of cleanliness, etc. In women the lesions of chancroid are situated about the clitoris, introitus vagine, and on the labia, perineum, and about the anus; very rarely, on the cervix uteri or the walls of the vagina. When extra-genital chancroids do occur, it is usually by auto-infection rather than by direct infection; ¢.g., a careless patient in caring for his chancroids may smear some of the discharge on his fingers and inoculate some part of his integument by scratching. The number of lesions in a case of chancroid is variable; it may remain as a single sore, but is usually multiple, the multiplicity being due to the highly inoculable char- acter of the chancroidal pus. The virus can undoubtedly penetrate sound mucous membranes when deposited thereon, while on the skin entrance is gained through hair follicles or minute abrasions. The power of reproducing itself in the same individual is perhaps best shown in the case of filthy women who allow the discharges from chancroids about the vulva to run down over the perineum and about the anus, or even the upper part of the thighs, thus causing very numer- ous ulcerations in the localities named. In determining the character of a doubtful sore, it is sometimes of value to try auto-inoculation. In doing this a spot well removed from the large chains of lymph glands should be selected. The pus from chancroids is always capable of auto-inoculation. The size of chancroidal ulcerations varies from that of a pea in mild cases up toasilver dollar or larger in severe serpiginous cases. The size of the lesion is of compara- tively little value in making a diagnosis. The shape of the ulcer is perhaps oftener roundish or oval, but this depends upon the location and is of no importance. The duration of the disease is modified so much by the patient’s general physical condition and habits of life, as well as by the medical management of the case, that it is difficult to give anything like an exact time limit. There are three fairly well-marked stages in the dis. ease: the period of destruction, followed by an interval in which the condition remains about stationary, the ulcer- ations not extending; and this in turn is followed by the period of repair, where the character of the ulcer changes; REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. it appears less sluggish, bright red granulations begin to show in the floor of the ulcer, and there is then a greater tendency to bleed; any necrotic tissue which may be pres- ent comes away and the sore heals by granulation. In uncomplicated cases in otherwise healthy individuals, the course is run in from two to six weeks. Too vigorous exercise, alcoholic indulgence, and complications such as phimosis, gangrene, or phagedena (the two latter are very rarely seen at the present time), may extend the course much longer. Draenosis.—Chancroid is to be differentiated from the initial lesion of syphilis, from the mucous patches of sec- ondary syphilis and the gummatous ulcerations of late syphilis, from herpes progenitalis, from ulcerations ac- companying scabies of the genitals, and from epithelioma. The initial lesion of syphilis is to be distinguished from chancroid by its well-marked period of incubation, the sore usually appearing in from two to four weeks after exposure. Instead of a suppurating ulcer we are apt to find a more or less well-marked infiltration of the tissues about the sore with an erosion of the surface, and with very little purulent secretion. The striking features of chancroid are the non-indurated, suppurating ulcers which are always capable of auto-inoculation. In syph- ilis, on the other hand, we are impressed by the indura- tion (the sore often feels like a foreign body in the tissues when taken between the thumb and fingers), and by the fact that the number of sores, representing so many points of inoculation, always remains the same from the beginning to the end. Another important difference is the behavior of the neighboring lymph glands in the two diseases. It has already been pointed out that usually in chancroid a single gland in the chain is swollen, painful, and tender, and the process not infrequently ends in suppuration. In syphilis the glands in the whole chain are affected, are non-inflammatory, neither painful nor tender, they are freely movable under the fingers and have a peculiar hard, shotty feel. It is rare for the glands accompanying the initial lesion to break down. In a case of chancroids one can never rule out the possibility of a coexisting syphilis until the incubation period of the latter is past. In women especially, mucous patches of syphilis oc- curring about the vulva and anus may very closely simulate chancroids. The same lesions are found in men usually about the glans penis. These lesions will be found to have not the clean-cut edges, purulent secre- tion, or the velvety, worm-eaten-appearing base of chan- croids, but a grayish, smooth, opaline appearance. The secretions from these mucous patches are highly con- tagious and foul-smelling, but are never capable of auto- inoculation. The diagnosis, in the case of mucous patches, can gen- erally be easily determined by the presence of other syphilitic manifestations or by the history. At times a late syphilitic ulcer may appear about the genitals and very closely simulate a chancroid. The history of a previous syphilis, the non-involvement of the glands in the vicinity, and the lack of evidence of auto-infection will hardly allow a mistake to be made. Herpes pregenitalis.—In herpes there is a sense of burning and itching before the eruption appears. At first the contents of the vesicles are clear and not yellow like chancroids, though they may become yellowish later, when pus is present. The covering of the vesicle easily ruptures and the small ulceration resulting may extend somewhat in depth, but not in breadth, unless two or more vesicles run together. There is seldom any disturb- ance in the lymph glands and the disease runs a self- limited course. The spots dry up and disappear in a week or ten days There is oftenno history of exposure, and certain individuals are prone to repeated attacks. It occurs in both sexes, and it is not very uncommon to see a person with a herpes progenitalis and a herpes labialis at the same time. Ulcerations about the genitals due to scabies are to be distinguished from chancroid by the presence of burrows Chancroid, Chancroid, and marks of scratching on the foreskin, and evidence of scabies on other parts of the body. A. peri-urethral abscess occurring in the sulcus, back of the glans, might at times suggest a chancroid, but if its sharply circumscribed appearance and inflammatory character are borne in mind, together with the history of a ‘previous gonorrhcea, the liability of a mistaken diag- nosis is very small, CoMPLICATIONS.—The complications of chancroid are phimosis and paraphimosis, lymphangitis and suppurat- ing bubo; phagedeena and gangrene are very rarely seen nowadays. Phimosis and paraphimosis not infrequently occur during the course of chancroid. In phimosis the whole prepuce may become swollen, red, or reddish purple in color, tender and doughy to the touch, with a more or less profuse foul, purulent discharge. Often there will be one or two small ulcerations at the margin of the foreskin which show the nature of the sores within. Occasionally, in unrelieved cases, the pre- puce ulcerates through and allows the glans to protrude. Paraphimosis is less common, though not much less severe a complication. The swelling of the parts may be very great, and the line of ulceration which occurs in the line of constriction back of the cedema, at right angles to the shaft of the penis (nature’s attempt at relief of the condition), becomes infected with the chancroidal virus and extensive destruction of tissue may result. Lymphangitis and Lymphadenitis.—As has already been mentioned, the lymphatics of the penis are often involved and are felt as a hard, tender cord beneath the skin. The condition of the lymph glands has already been described. TREATMENT.—In the treatment of chancroids it is essential that the patient keep as quiet as possible. All excessive or violent exercise, running, skating, dancing, etc., is to be avoided. The next step is to keep the sores thoroughly cleansed with soap and water and antiseptic solutions. It is al- ways well to use the lotions as hot as is grateful to the patient, for heat in itself is exceedingly beneficial in the treatment. The principal solutions in use to-day are corrosive sublimate, 1 to 1,000 or 1 to 2,000; creolin, 1 to 250; lysol,1to 500; formalin, 1 to 50; carbolic acid, 1 to 50; boric acid in saturated solution. After cleansing with the wash, the surface of the ulcers should be carefully dried and dusted over with one of the following powders: aristol, europhen, iodol, calomel, acetanilide, or iodoform. Perhaps the last named is the most efficacious of any of the powders named for use in the early stages or up to the appearance of healthy granulations. Of courseits odor is a great objection, and its use is as a promotor of healthy granulations. It should ordinarily be used as a fine powder, but may be suspended in ether or gly- cerin. The deodorized iodoform is of little value. Care should always be taken not to irritate the sores, either by manipulation or by the dressings employed. This may be termed the conservative or symptomatic treatment; opposed to this may be given the heroic or radical treatment. Here the attempt is made to change at once the chan- croidal ulcer into a simple one by thoroughly destroying the surface of the sore. This is usually accomplished by the actual cautery or by the application of caustic acids. Nitric and carbolic are the ones commonly used to-day. Excision should rarely, if ever, be done. Before cauter- izing a sore it should be carefully cleansed and cocainized, and then the acid applied thoroughly to the floor and edges of the ulcer, with a bit of absorbent cotton wound around the end of a wooden toothpick. Care must be taken to restrict the action of the acid to the diseased tissue, and the action of nitric acid can be controlled by the use of bicarbonate of soda. The stick of silver nitrate is a popular caustic with the laity, but its use is to be severely condemned. — Its action is superficial, irritating to the tissues, productive of cedema and suppurating bubo, and should never be em- ployed as a means of destruction of the sore, but asa 197 Change of Life, Change of Life. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. stimulant to sluggish granulations it may be of service. However, it should never be used early. Caustics should never be applied to a sore that cannot be thoroughly ex- posed and properly cared for. After cauterizing, the sore should be treated with moist bland dressings for a time, lint soaked in lead-water wash or a solution of boracic acid or black wash, and changed frequently. After a few hours this dressing should be changed to one of the powders already named. As a general rule, ointments and greasy preparations should not be employed, except, perhaps, over the powder to keep the cloth from sticking and thus prevent bleeding when the dressing is changed, or when the ulcer is granulating, to promote healing. Internal medication, unless the individual is much run down, is not usually needed. General tonics (iron, cod-liver oil, syrup hypo- phosphites, etc.) may often be of service in debilitated cases. Mercury should never be given in a case of chancroid. In old sluggish chancroidal ulcers, a thorough curetting is sometimes of service. In women the treatment is more difficult by reason of the inability to keep the parts clean and reach all the points of infection. Hot injections of soap and water or borax and water followed by a cor- rosive douch, 1 to 5,000, should be used once or twice daily, and one of the powders already mentioned dusted on all the available spots. A ten to forty per cent. solution of formalin gently applied, or a saturated solution of pyoktanin blue, has been highly recommended in sluggish cases. In general, it is always advisable, in the vast majority of cases, to avoid using any sort of caustic. When used, it should be applied only to carefully selected cases, and should be used with the greatest care. C. Morton Smith. CHANGE OF LIFE.—This term, in common use, sig- nifies the series of phenomena which are apparent at the end of the child-bearing period. It is applied exclusively to women, though an analogy has been observed between some of the conditions which affect women at the period in question and similar con- ditions which have frequently been noted in men at the time when their physical powers have reached their culmination. The term which is generally accepted and used by medical writers as correlative with change of life is meno- pause. This term is sufficiently explicit for only one link in the chain of phenomena which comprise the change of Jife, to wit, the cessation of the monthly flow. For this reason the common term is the more exact and comprehensive and therefore presents claims for its general use. The change of life is really one of the great epochs in the life of woman, for it not only serves as the boundary line between the period in which she is able to reproduce herself and her species—period of fruitage,—but it marks the limit of the progressive stage of her physical condi- tion in general, deterioration being henceforth the pre- vailing process, whether it develops slowly or rapidly. Time of its Occwrrence.—Like all the other functions of animal life, this one also is subject to great variations both as to the time of its occurence and the events which characterize it. According as it occurs early or late in life it may be premature, normal, or retarded, and it may be natural or artificial according as it is or is not solely the product of physiological forces. In temperate climates we may expect its appearance in the majority of cases between the fortieth and forty- fifth years; family or race peculiarities may advance it two or three years or defer it for an equal period. It is premature when it occurs prior to the fortieth year and it is retarded when it occurs later than the fifty- fifth. Influences which Modify its Occurrence and its Course.— Race. The nearer a tribe or race of human beings ap- proaches the lower animals in its intellectual develop- 798 ment the less marked will be the menstrual function in its women. Menstruation is quite clearly the development or evo- lution of the rut or wstruation in the lower animals. In the apes and monkeys we observe very frequently a dis- tinct regularity in what may be termed for them the menstrualflow. Neither in the animals nor, so far as my knowledge extends, in the lower orders of human beings are there well-defined conditions which might constitute the change of life, at least as this experience is observed in the more advanced races. In proportion as a community or race advances in civilization do we see the menstrual function and the change of life assume distinctness and character. While it does not follow that their unusual or pathological features are necessarily the result of civilization, since there are countless examples in which no appreciable disturbance, is experienced from either, it is certainly true that such disturbance does accompany civilization. Climate. The influence of extremes in temperature acts upon the change of life precisely as we would antici- pate. In the tropics vegetation is luxuriant, matures early, and is profuse in its fruitfulness, but the duration of its life is shortened by the very excess of this profuse- ness. It is the same, to a certain extent at least, with human females who are native to the tropics: they ma- ture and bear their children early, and in frequent in- stances reach the menopause between twenty and thirty. This has been observed especially of the Arabs of the desert. To the Caucasian races transplantation to the tropics means a distinct lowering of vitality, with a great diminution in reproductive power and a consequent tendency to the early cessation of the menstrual function, and the advent of the change of life. In the Arctic regions the effect of extreme cold upon vitality is similar to the effect of extreme heat, though it may be made en- durable to a greater degree than the latter. The natives of the Arctic regions are stunted in form and more or less. deficient in vitality. This is especially the case after they have endured the rigors and the darkness of the long Arctic night. The women seldom mature earlier than the twentieth year, menstruate very infrequently, and seldom have more than one or two children. The duration of life is not great, and the change of life comes between thirty and forty. Altitude. The significance of this factor is due, of course, to the change in the air pressure. Women may gradually become habituated to any condition of atmos- pheric pressure, but the effects which obtain prior to. such habituation are very distinct. A change to the sea level by one who has lived away from the sea and at. more or less of an elevation generally suspends or other- wise disturbs the menstrual flow, and in cases in which there is decided constitutional disturbance it is possible that the change of life might be hastened by such resi- dence. Those who go from the sea level to reside at altitudes. of six thousand to seven thousand feet or more experience, on the other hand, increased profuseness in the menstrual flow, the externalair pressure being greatly reduced. Of the influence of such reduced pressure upon the change of life except in prolonging its duration and increasing the frequency and profuseness of its hemorrhages, I am not prepared to speak. I know of no statistics bearing directly upon this subject, which is one of the many fruit- ful themes in climatology still awaiting investigation. General. Physical Condition.—The general condition of a woman has much to do with the inauguration of the: change of life and with the events by which it may be characterized. Those who suffer with grave constitu- tional and visceral diseases which seriously impair their vitality are almost certain to experience an arrest of menstruation and often other symptoms which accom- pany the change of life. Those who suffer with tubercu- losis, syphilis, general anzemia, chronic diseases of the liver or kidneys, etc., are in this category. The acute wasting diseases sometimes produce so profound an im- pression that the menstrual function is entirely obliter- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ated. On the other hand, the malignant diseases of the genital organs, if present at a time when the change of life might be expected, cause its unlimited delay. I do not recall a case of such disease, in a very large experi- ence, in which the change of life ensued after the malig- nant disease had begun its destructive career, In fibroid tumors of the uterus, especially those which are charac- terized with much discomfort and hemorrhage, it was formerly the custom to hold out the hope that all trouble would cease when the change of life brought its beneficent issue. In most cases this has proven the most unsatisfac- tory will-o’-the-wisp hunting by which a poor mortal could be deluded. The change of life again and again escapes the grasp, until finally it comes to mean that transformation which arrives for us all “ when this mortal shall put on immortality.” The beneficent influence of modern gynecology has removed the veil of ignorance in regard to this subject, and the early removal of these tumors has alike brought on the change of life and the relief of many troublesome symptoms. The change of life comes quite early in women who become excessively fat. Such women are usually sterile. Their physical condition unfits them for the normal experiences of pregnancy and parturition, menstruation is infrequent, scanty, and painful, and it is not unusual for the change of life to occur within a few years of the appearance of the obese condition. Surgical Procedures.—Certain surgical operations are conducted with the deliberate intention and purpose of bringing about the change of life. Such are all opera- tions in which the ovaries are entirely removed. It is estimated that in ninety per cent. of cases of removal of the ovaries menstruation is at once arrested. If the uterus and Fallopian tubes are also removed the percent- age in which such a result is obtained will be even greater. There are no other surgical procedures which act so direct- ly to induce the change of life as does extirpation of the ovaries. Operations which may be followed by prolonged suppuration and invalidism by impairing the general nutrition and reducing vitality may result in arresting menstruation temporarily or permanently and in bring- ing about the premature appearance of the change of life. Occupation.—Both a direct and an indirect influence may be exerted by occupation upon the subject which is under consideration. - Such occupations as keep a woman in an elevated temperature during most of the day are very disturbing to the menstrual function, have a very decided tendency to produce obesity and may induce the change of life prematurely. Cooks, laundresses, and bakers are particularly subject to such influences. Other occupations which impair nutrition and vitality also dis- turb the menstrual function and hasten the change of life. Workers in chemical factories and laboratories upon arsenic, copper, lead, phosphorus, and other poisonous substances, workers in mines, cellars, in badly lighted, badly ventilated, and damp surroundings are included in this category. Other sufferers are those whose work is exhausting and unwomanly and predisposes to wrinkles and premature old age; such are fishwives, field workers, bearers of heavy burdens on the shoulders or head, me- chanics’ assistants who may carry tubs of mortar, casks of water or other heavy burdens, all these being types of laborers which one sees much more frequently among the laboring classes in Europe than in this country. Excessive Fertility.—With many women the reserve capital of vital force is not large. Bearing children in rapid succession until five, six, or more have been borne in as many years exhausts that capital, and then follows the change of life while the woman is yet young. The reason for this is perfectly plain and is seen in the results which follow over-productiveness in animal or vegetable life wherever we may take the trouble to investigate it. Such a result can hardly be regarded as disease, but sim- ply as the taking up of a certain amount of capital to which nothing remained to be added by way of replenish- ment. Dissipation and Vice.—The number of women who lead irregular and vicious lives is so great that it would Change of Life. Change of Life. seem as if important deductions might be made from the study of such lives. It has happened to my experience to see quite a large number of women of the vicious and depraved class of all ages. These women suffer greatly both with acute and chronic diseases of the pelvic organs; they frequently suffer with profuse hemorrhage from the uterus, and their excesses very often result in sterility, so that if the vicious life is followed by marriage, it is not likely to be a fruitful marriage. It has been a matter of surprise to me, again and again, that the excesses in sexual intercourse on the part of prostitutes and others do not arrest menstruation and bring on the change of life. Of course irregular habits, late hours, excesses in alcohol, etc., frequently break down the health, and the menses may be arrested as the result of ansemia, etc., if the woman does not die promptly from exhaustion or some acute disease, as is the result with many. As a matter of fact I have seldom been called to record such an occurrence; indeed, the stimulation of the sexual organs and the careless, irresponsible life of many of these women seem to improve nutrition, and for a long time, at least, their physical condition is surprisingly good. Phenomena and Duration.—There are certain phe- nomena which are almost invariable and others which are only occasional to the change of life. We must also re- member that with some women the transition is imme- diate and without appreciable symptoms, except that the ordinary monthly flow abruptly ceases. The leading symptoms are practically the same whether the condi- tion is the natural change or one which is induced by disease or surgical procedure. To those who experience it while still far removed from the usual period of time when it is to be expected, the symptoms may be exagger- ated; but not necessarily so, for I have seen young girls go through this change with scarcely any discomfort or unusual happening. Cessation of the Menstrual Flow.—The leading symptom is the disappearance of the regular monthly bloody dis- charge. Thiscessation may occurabruptly, the flow ap- pearing one month, disappearing the next and never reap- pearing. This may be explained by the fact that physical maturity has been reached, just as the fruit falls from the tree when it is ripe; or it may be the result of disease, of removal of the ovaries, of intense emotion, etc. If the cessation of the menses occurs in young women, the pos- sibility of its restoration in due season must be considered. Instead of an abrupt cessation the flow may reappear at regular or irregular intervals, two months, four months, six months or longer, finally ceasing altogether after one, two, or three years. Kacessive Flowing.—A very marked feature in some: cases, when the flowing has become irregular, is its pro- fuseness. It was formerly thought proper to do nothing for this symptom on the supposition that it was simply a natural discharge. I have striven diligently for years to combat this view. Excessive loss of blood is always unusual, abnormal, and should be investigated and arrested. The condition of the uterine mucous mem- brane usually calls for active treatment in such cases by the application of astringent substances to it or the re- moval of granulation tissue, which may be the cause of the hemorrhage, by the curette. Tumors and other dis- ease of the uterus assume particular importance at this time, and one should never leave to the unaided efforts of nature the disposal of a burden at this time which she may be unable to dispose of or only with great risk to the patient’s life. Flushing and Other Vaso-Motor Disturbances.—Almost as common a symptom as the arrest or irregularity of the menses is the vaso-motor disturbance which occurs with- out warning many times a day until toward the end of the change, and is manifested now by flushing and heat, and now by pallor and chill. The experience of each paroxysm may continue but a moment, but it is annoy- ing and in some cases depressing and weakening. What should cause this peculiar vaso-motor influence, now paralyzing and again stimulating the vascular system, 799 Channel Islands, Chatoolanee Springs. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. can be only a matter of conjecture. It is an experience which is so universal that it may be regarded as not far removed from the physiological. It is one of the first symptoms which occur, it continues two or three years, and by that time it has become endurable by its very frequency. With some women it continues uninter- rupted to the end of life. It seems to make no difference whether the mencpause is natural or induced as to the frequency and intensity of this symptom. It may be expected, however, that with those to whom the change comes early in lifs it will continue longer, as a rule, than with those to whom it comes as an entirely natural experience. Mental and Nervous Phenomena.—One of the many notions concerning the change of life which formerly prevailed was that since it was a erdtical time all sorts of unpleasant things might be expected to develop in con- nection with it. Ifa woman became crazy at that time it was the change of life which did it, and it was more than likely that she would become crazy if she had any predisposition or predilection to mental instability. The arrest of the menses and the disturbance of the blood tension undoubtedly may cause brain disorder in those who are predisposed to such trouble, and this may vary in its manifestation between headache and violent delirium terminating in mania or melancholia. Many women are gueer or unusually hysterical at this time, neuralgias of all varieties are frequent, insomnia is not infrequent, and a disposition which has heretofore been amiable may be suddenly or gradually transformed into one to which the most unusual or grotesque desires or actions are possible. The outbursts in such cases should not all be attributed to the change of life, they are due in part to the previous inheritance of the individual and in part to the tissue changes which take place. Besides, the great majority of women have none of these experi- ences at all, so that they must be considered exceptional and not a customary accompaniment. Changes in Nutrition.—Changes in nutrition are a noteworthy feature of this period, the active upbuilding time of life is over, and the tissues now and henceforth are less substantial. Muscular tissue tends to degenerate and atrophy, and fat is accumulated. This may lead to improvement in the general appearance and rounding of the figure, but it may also lead to grossness and obes- ity. Personal beauty is lost in some cases while an un- usual attractiveness is acquired in others. This period and the remaining years of life being the era of degeneration, it is not strange that cancer of the breast, the womb, and other genital organs should be found at this time more frequently than in earlier life. Cancer is not necessarily a feature or customary accom- paniment of the change of life. This is a fact which I have insisted upon for years in spite of a prevalent opin- ion to the contrary, both in the profession and in the laity. It frequently coexists simply because the change of life stands at the entrance of the degenerative period. We look for cancer in men in its greatest frequency at the same period of life that we look for it in women; the ending of the child-bearing period and the cessation of the menses must therefore have little to do with the de- velopment of malignant disease. Disturbances in Various Organs of the Body.—These have been frequently noted, and in a book which was written by me upon this subject (“The Menopause,” D. Appleton and Co., 1897) various complicating affections have been alluded to. It has always seemed to me very necessary that one should carefully distinguish those complications which merely coexist from those which cause or are caused by the change of life. Dimness of vision has been reported as an accompaniment in many cases, also liver engorgement or other derangements in efficient wor king power of the kidneys and urinary blad- der, loss of appetite, indigestion and constipation, rapid action of the heart and dyspneea. These, it will be ob- served, are all functional disturbances, and it is such rather than organic lesions of which the change of life is most likely to be the cause. 800 Impregnation after the Change of Life has Occurred.— The question is an interesting one, and it has often been asked whether impregnation could occur after the men- strual flow had entirely ceased. This question may be regarded as entirely settled, indeed it may be said that impregnation has very little to do with the menstrual flow or the menstrual flow with it. It is said that the Esquimau women are impregnated customarily before the menses have appeared. Many instances have been observed in which a similar event has occurred in our own latitude before the appearance of the menses. The facts in regard to impregnation after the menses have ceased and the change of life has been concluded are equally authentic and definite. It is not usual for such an event to occur, but it does occur occasionally. It is believed that the ovaries continue their functional activ- ity from the beginning till the end of life, and in not a few instances pregnancy has taken place many years after it was supposed the child-bearing function had ended. Iam personally familiar with cases in which this interval has been ten to fifteen years, women from fifty to fifty-five years of age giving birth to healthy children. Equally strange are those cases in which pregnancy occurs when both ovaries have been removed. I know of two such cases reported by reputable and talented men. Hither the ovaries were not entirely removed, or there was a supernumerary ovary, or there was some hidden cause which cannot be explained. Andrew F. Currier. CHANNEL ISLANDS. CHARCOAL.—The essential constituent of charcoal is the element carbon, which, as it occurs in charcoal, pre- sents itself asa black substance, insoluble, infusible, odor- less and tasteless. The medicinal virtues of carbon reside solely in the singular absorbent property of this element. As represented by the substance charcoal, carbon tends strongly to absorb and hold fast gases and many organic principles, notably alkaloids and odorous and coloring matters. And in the case of such of these bodies as are oxidizable, the fact of their retention in the meshes of the charcoal mass leads to their ultimate chemical transfor- mation by oxidation. Charcoal thus operates indirectly as an oxidizing agent, and thus is.practically available as a decolorizer, deodorizer, detergent, and, so far as noxious products of zymotic processes are concerned, also as a disinfectant. Charcoal is used by the pharmacist to decolorize and to separate organic principles, and by the physician to deodorize and hasten oxidation in the con- tents of receptacles for excreta, to deodorize foul dis- charges, and, given internally, to absorb and hold the substance of vegetable poisons, such as alkaloids, until their evacuation can be determined, and, by absorption and secondary chemical conversion, to dispose of the noxious products, fluid and gaseous, of fermentation of the ingesta in a dyspeptic stomach. Charcoal is official in the United States Pharmacopeeia in the following forms: Carbo Animalis, Animal Charcoal. Under this title is recognized the common so-called animal charcoal or bone- black, that is derived as a black pulverulent residue from the heating of bone to redness ina closed vessel. Animal charcoal occurs in “dull black, granular fragments, or a dull black powder, odorless, nearly tasteless, and insolu- ble in water or alcohol. When ignited, it leaves a gray- ish or yellowish-white ash, amounting to about eighty- five per cent. of the original weight of the portion taken ” (UNS5 P.). Animal charcoal is official as the basis for the following preparation : Carbo Animalis Purificatus, Purified Animal Charcoal. Animal charcoal, in No. 60 powder, is digested with di- luted hydrochloric acid on a water-bath for many hours, and the undissolved residue then freed from the acid b thorough washing with water, dried, and put up in well- stoppered bottles. By this procedure the calcic salts, which form so large a proportion of the weight of crude See Guernsey. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Channel Islands, Chatoolanee Springs, animal charcoal, are dissolved out, and the carbon is thereby obtained practically pure. Purified animal char- coal is “a dull black powder, odorless, tasteless, and in- soluble in water, alcohol, or other solvents” (U. 8. P.), Probably because of a peculiarity of its texture, animal charcoal decidedly surpasses wood charcoal in the prop- erty of decolorizing and ot separating and holding vegeta- ble principles. It is, therefore, the form of charcoal most used by the pharmacist, and should be selected also by the physician where the purpose is to withhold swallowed vegetable poisons from absorption. But in this applica- tion it should be remembered that the action of the char- coal is, so to speak, mechanical only, and the use of the same, therefore, should be merely accessory to measures to secure evacuation. The charcoal should be given freely, by the spoonful, in suspension in water, until from half a tumblerful to a tumblerful shall have been taken. Carbo Ligni, Charcoal. Under this title is recognized officially “charcoal prepared from soft wood and very finely powdered.” When well prepared, wood charcoal contains but a very small percentage of mineral matter, and, therefore, may be regarded as practically all carbon. For medical purposes it is pulverized, and yields an ex- ceedingly fine, light, black powder, odorless, tasteless, and insoluble. Upon exposure it attracts moisture, and it is in best condition, therefore, when freshly made. It should: be kept in tightly closed receptacles. Wood charcoal possesses in high degree the property of absorbing gases of certain kinds, and notably the foul- smelling products of zymotic processes. For deodoriz- ing purposes it may be relied upon to absorb and effect the decomposition of from fifteen to twenty timesits bulk of gas. It thus makesa good application to privy vaults or cesspools, a pailful of powdered charcoal, as freshly made and as well preserved from damp as possible, being thrown into the receptacle once or twice a week. To wounds or sores yielding offensive discharges charcoal may be applied by dusting upon the surface, by strewing upon the face of a poultice, or by quilting the powder between two layers of cotton wadding, such quilt being then used as the wound dressing. In dyspepsia, with acidity and flatulence, relief often may be secured by ad- ministering powdered charcoal in quantities ranging from half a teaspoonful to a tablespoonful. It should be, if possible, freshly made, and is more effective if taken dry. Otherwise it is given mixed with water or milk. Char- coal should not be taken in large doses too frequently, for under such circumstances considerable mechanical irritation has been known to follow. In mild dyspeptic cases, quite small doses, such as from 0.12-0.30 gm. (gr. ij-v.) may be all-sufficient, and such quantities may be taken without objection. A sample of charcoal that has lost potency by keeping recovers the same on being recalcined. Edward Curtis. CHARLESTON, S. C.—A city of 65,000 inhabitants, and one of the chief seaports of the South, situated upon a point of land between the mouths of the Ashley and Cooper rivers, several miles from the Atlantic Ocean. It is an attractive. old-fashioned town, with rich vegeta- tion of a more or less semi-tropical nature. It is a con- venient and interesting place to spend some time in, on one’s way north from the more Southern resorts, espe- cially in the spring. The magnolia gardens in the vicin- ity are most interesting and well worthy of a visit. In- deed, both by water and land the excursions are many and attractive. The writer recalls very vividly the delight of a visit here in the spring when returning from Florida. The mild balmy atmosphere, the profusion of roses, the jasmine, the strawberries, the quaint and attractive streets and residences, and the numerous excursions, were a con- stant source of pleasure. As will be seen from the climatic table, the winter and spring climate is amild, equable, marineone. The prox- imity of the sea renders the relative humidity greater than at the resorts farther inland; hence this is not a VOL LE —ol favorable climate for a permanent residence for the consumptive. CLIMATE OF CHARLESTON, S. C. LATITUDE, 32° 47’; LONGITUDE, 79° 56’. PERIOD OF OBSERVATION, 12 YEARS 10 MONTHS. Janu- Novem-| x, Data. ary. March July. Ber Year. Temperature (Fahr.)— - Average or normal,..... 49.5° 57.8° 82.8° 762° 65.9° Average daily range....| 14.6 15 14.1 14.1 Mean of warmest.......| 58.4 67.1 90,2 65 Mean of coldest......... 43.8 52.1 76.1 50.9 Highest or maximum...| 80 85 104 82 Lowest or minimum ....| 23 28 67 28 Humidity— Average relative........ 75.4% | 69.6% | 74.38% | 74.7% | 73.8% Precipitation— Average in inches ...... 3.77 4.47 7.18 3.51 59.9 Wind— Prevailing direction .... N. S.W. S.W. N.E S.W. Average hourly velocity pte ect Clee onre Oierrecins 7.3 8.8 Kies 3) 7.9 Weather— Average number of clear GAYS omcyastte sie chatte wise 9.5 2.7 10.4 11.5 134 Average number of fair GAYS esata ie saeeenee at 10.5 10.8 14.6 10.5 140.3 Average number of clear and fair days'..-...... 20 23.5 25 22 274.3 Edward O. Otis. CHARLESTON ARTESIAN’ WELLS. — Charleston County, South Carolina. Post-OFrFIce.—Charleston. Several artesian wells in the city of Charleston have been found to be impregnated with mineral ingredients. Those mentioned in the Geological Reports are the “Old Artesian Well,” the “Citadel Green Well,” the “ Commer- cial Cotton Press Well,” and “Chisholm’s Mill Well.” We introduce the following analysis of the first of these, made in 1868 by Dr. C. U. Shepherd, Jr. : OLD ARTESIAN WELL. ONE UNITED STATES GALLON CONTAINS: Solids. . Grains. SOG DICHEDONALO: avec. octets nies tester fe rertials o/csletore 71.06 Calciumubicarbonat® vc.ccc me citnaces wom cie Gace ca tn caeele cake 12 Magnesium bicarbonaters ceils ieresieoty ane: te. .02 Sodium! chloride sueaccanee mae ce eee ean ecen 63.38 SULICa Maa ieccsee te teh ee see tibia serene Trace OTTANICHMATLEA rateisteiateieis hs wtostencte ce sels slalalciens cise suteicitiece ce Trace. EY OUR OXIG Csr clots ctercateel toe ete ste cbetetat tots ats ctitorctiiaetentare Trace. ATU UD OXING canes ieee nckeic ke Lbia tte tee on nee 79 Cardoliciacld Tee siursctceuittcsidasiho cet ee tee. aoe cies Trace. 135.37 This water has a temperature of 87° F., and is there- fore a thermal. The well is 1,250 feet deep, and the flow of water is estimated at 1,200 gallons per hour, The Commercial Cotton Press Well contains a consider- able proportion of sulphate of magnesium. James K. Crook. CHATTOLANEE SPRINGS. — Baltimore Maryland. Post-OFFIcE.—Chattolanee, Hotel. Access.—Via Northern Central Railroad from Balti- more, 33 miles. These springs are delightfully located in the Green Springs Valley. They are six in number and yield 1,500,000 gallons of water daily. The waters are not strongly mineralized, but are quite remarkable for their great purity and freedom from organic matter. The following analysis was made by Messrs. Lehman and Mager, of Baltimore: ; County, ONE UNITED STATES GALLON CONTAINS: Solids. Grains MAGnesitimiCarDOnelonacde steven cas ses eet coc bce arses 1.81 CAlGIUM:CAFDONAIOS. sastitcaiiee vaceinslecge ceeea beasts ne 4.62 Chattanooga, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Cherry. Solids. Grains. Sodium Chloride. assests ectteeretecstreteloiomech eteteans alii SOGTIM: SULPNALS,/. ors sieves eiclbieieralclele of Serer ioniclelne stareulen es 08 Potassium sulphates, cricsen oc tetinccte ve selen ociee deliveries 10 TVOD, ‘ORTAG Sa ieves etaterouncotatadua ome ettete ys eiee ciate letnie, cei siciptnie pts heea Trace AGH 5 Ss ui icterstalerate ote Stctereca cttve ts bintets s tictne wis oteisverersiorerate sis Trace. STITCH ards isiane nratereromrocd epee et taarecs texatbre osu arate raleiocs a ere otaletebeiate 24 Carbonic. acid (com Dime) eracwrcutine sce cine sirre/neteisieleisiete a TOtBLSOUGS ye mesic c ce clr elev nielulucs nl iatettpsie eet emrateye Mere 8.28 Temperature of water at springs, 52° F. The water is of the light alkaline-calcic class. In ad- dition to its properties as a table beverage it is said to be very useful in dyspepsia and indigestion and the early stages of Bright’s .disease. The water is extensively sold in Baltimore and other cities. James K. Crook. CHATTANOOGA, TENN.—A city of about 50,000 in- habitants, situated in the southeastern portion of Ten- nessee, upon the Tennessee River. It is 762 feet above sea level, and the surrounding mountains are from 1,320 feet—Missionary Ridge—to 2,160 feet—Lookout Moun- tain,—both of which points are easy of access. The scenery is varied and beautiful, and the atmosphere is exhilarating and pure. The spring is early, opening in March, and the vegetation rich and varied. The soil is dry and loamy, and the drainage good. There are oc- casional winds and fogs, but the city is so surrounded by mountains that it is greatly shielded in this way from the winds. The climate is indicated in the accompanying table, kindly obtained for the writer by Dr. W. A. Applegate, of Chattanooga. From this it is seen that the winter climate is moderate and the summer not ex- cessively hot. The relative humidity is quite high, and the average number of clear and fair days not remarkably large in comparison with other health resorts in the South. The daily range of temperature is also seen to be large. CHATTANOOGA, TENN. LATITUDE, 35° 4’; LoneirupE, 85° 15’. in the pure and bracing atmosphere, mild winter tem- perature, and attractive scenery, substantial climatic ad- vantages in the treatment of pulmonary tuberculosis; for the chief end of all climatic treatment of consumption can well be accomplished here, namely, constant ex- posure to pure outdoor air. A sanatorium, for instance, on Lookout Mountain, conducted as Falkenstein or the Adirondack Cottage Sanatorium is, would doubtless ex- hibit equally good, if not better, results. Formerly malaria was very prevalent here, but since the sanitary condition of the city has been improved, this disease is said to have disappeared to a very great extent. The outdoor attractions are many and varied; excur- sions to the various battlefields—Chickamauga, Mission- ary Ridge, Lookout Mountain, and Orchard Knob—are all full of interest. The view from Lookout Mountain, as the writer can testify from personal experience, is a striking one, looking down upon the winding river and the other lesser heights. The roads are good, and driv- ing and wheeling are popular amusements. The accommodations are excellent both as regards. hotelsand boarding-houses. “ Lookout Inn” on Lookout Mountain is open all the year and affords the best of ac- commodations. Chattanooga is a railroad centre and is easily accessible: from all directions. Edward O. Otis. CHAULMOOGRA.—CuawovL-Munert. The seeds of two species of Gynocardia (fam. Flacourtiacee) of South- eastern Asia; also the oil expressed from them and the: bark, the latter not being an article of commerce with us. The seeds of commerce are commonly referred to G. odorata R. Br. This species, however, does not yield the ordinary seeds, which contain no prussic acid, but a. different variety, rare in commerce and rich in prussic acid. The species yielding the commercial seeds appears. undescribed, though it is indefinitely referred to by vari- CLIMATIC DATA FROM OBSERVATIONS FROM 1879 To 1899 INCLUSIVE. Pr) ae ee 3 3 5 =| 2 = s e = Temperature (Fahr.)— WA VEFAGE:OF NOTMAL scr. scieie-vie aleve cicts ois elsiolarereferelniets 41.4° 45.4° | 51.1° Average daily: Tang enna eunaeecielioes RCO 16 17.4 | 18.7 Mean Of WArMesisescentcees scmvied circu 1 See 78 8 6 6 1 7 6 6 9 12 102 14° 118° || 45 13 13 |12 |13 |15 |17- | 180 3 1 1 1 3 0 3 3 8 42 11 11 12 14 12 9 8 9 11 186 rae Sasa ars 6 5. 1(25.1°8 | eae 63 17, 116 | 19 19 18 |16 |13 19 |17 | 228 * Lowest on record is — 10° on February 138th, 1899. Judged from its climatic conditions solely, Chattanooga would hardly fall within the list of genuine health resorts, although, like so many partisan reports upon health re- sorts, its “climate conditions” are vaunted as “unsur- | passed by any point in this country.” It is needless to say that the writer who makes this statement gives | neither full climatic tables nor any series of results ob- tained in the treatment of disease. Undoubtedly a resi- dence in some of the high localities about the city offers, 802 ous authors. The bark employed is possibly that of the: G. odorata, because prussic acid is developed in its in- fusion, which is also astringent, hence much like wild- cherry bark. It is used asa febrifuge. The fruit pulp is used to poison fish. The seeds and the oil expressed from them are extensively employed, externally and in- ternally, in the East, as a remedy for leprosy and for various skin diseases. The plant is a tree, and bears directly from its trunk. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chattanooga, Cherry. SS and large branches, globoidal berries, as large as a shad- dock, containing numerous seeds. The latter are about one inch or one inch and a quarter long, irregularly ovoid, angular from pressure, and dull gray. The kernel shrinks away from the testa in drying, the latter being thin and brittle. The oily kernel, at first white, becomes brown. It has a disagreeabfe odor and taste. The seeds consist of about half their weight of a brownish-yellow fixed oil, of a specific gravity of about .945. The active por- tion of this oil appears to be its 12 percent. of gynocardic acid, with 2 of cocinic, 4 of hypogeic, and 60 of palmitic acids. The oil has been considerably employed in pro- fessional practice, both externally and internally, in skin diseases. The dose is iij.—iv. after meals, gradually in- creased. Doses of Tl x. have been found irritating to most persons, resulting in vomiting and purging. Gynocardic acid has also been employed and is said not to cause nausea. An ointment made of fifteen to twenty- five grains of this acid to the ounce of vaseline has been recommended as an application to dry patches of eczema. False chaulmoogra is the seed of Hydnocarpus anthel- mintica Pierre, a related plant. It is similarly used in native practice, and also as an anthelmintic. : Henry H. Rusby. CHEILITIS GLANDULARIS APOSTEMATOSA. — Deriv.—yeiAoc, the lip; glandularis, having the appear- ance or form of glands; and apostematosus, from atéornua, an abscess. SynonyM.—Myxadenitis labialis. Under this name Richard Volkmann (Virchow’s Archiv fiir pathol. Anatomie, 1870, L., pp. 142-144) describes five cases of a peculiar chronic inflammation of the lower lip. Pearerone Swelling of the lower lip gradually en- sued without being especially painful and the lip became hard and tense, giving the face an unpleasant, idiotic ex- pression. The mobility of the lip was very much im- paired and in one case almost lost. The swelling in- volved the entire width and breadth of the lower lip to its union with the chin. In one instance the upper lip was also affected. The surrounding cutaneous integu- ments were somewhat erythematous in appearance. Upon close examination the mucous glands in all cases were found to be swollen to the size of a hemp seed and even larger, and were very numerous throughout the mucous membrane. When the lip was everted the fol- licular openings were seen to be much dilated and in some instances admitted a fine sound. On pressure, which gave rise to only moderate pain, an opaque mucous or muco-purulent discharge appeared, giving to the lip, which had been previously dried carefully, the appearance of being covered with small dew drops. In three cases abscesses occurred which originated in the glands or in the surrounding peri-acinous connective tissue. Furuncles formed in the fleshy part of the lip, which became inflamed without being especially painful, and at times the skin, but more frequently the mucous membrane, was perforated with small openings, and ° showed very marked tendency to fistulse and secreted a muco-purulent discharge for weeks and months. In one case there existed simultaneously on the inside of the lower lip twelve to fifteen such openings which admitted a larger sound with ease and led to irregular fistulous passages extending through the substance of the lip. True ulceration did not occur in these openings, in any case, and no evidence of syphilitic ulcers or plaques could be demonstrated on the lip or on the mucosa of the mouth and pharynx.* Two of the cases, although sub- jected to energetic treatment for some time with potas- sium iodide and local applications of silver nitrate, the point being introduced into the follicles under anesthesia, and applications of lead water, showed but very little im- provement. The remaining three cases were cured in four to eight weeks; potassium iodide, gargles of potas- sium chlorate, and mild cauterization being employed. All of the patients were adults. Three had previously been syphilitic shortly before the attack, and in one of these a fading syphilitic eruption on the palm was still present; with the exception of a few slightly enlarged lymphatics no local evidence of syphilis could be detected. Two patients were in perfect health and denied all his tory of syphilis. The course of the disease in all five cases was very similar, although differing in severity. It is quite certain that catarrhal inflammation of the labial glands existed in all these cases, accompanied by suppura- tion in places; actual suppuration occurred partly in the gland and partly in the peri-acinous connective tissue, hence Volkmann proposes to call the affection cheilitis glandularis or myxadenitis labialis. He is undecided as to the réle syphilis plays in this disease; he is, however, inclined to think that it does not exert a direct influence. It is more probable that the etiological factor is to be sought for solely in the catarrhal condition of the mouth and pharynx, which always existed simultaneously, and probably spread by means of the secretion of the oral cavity through the outlets of the labial glands to the acinous bodies. Emmanuel J. Stout. CHELOID. See Kelozd. CHEQUEN.—CueExkan. The leaves of Hugenia Chequen Molino (fam. Myrtacee). A large and beautiful white- flowered shrub of Chili and Bolivia, closely resembling the common European myrtle. The leafy twigs were originally used, but in this form by far the greater por- tion is inert woody fibre. The leaves average about half an inch or more in length, frequently with an ob- scure tooth on one side, thick, coriaceous, bright green, smooth and punctate, and aromatic in taste and odor. They contain four or five per cent. of tannin and two or three of volatile oil, the latter consisting chiefly of pinene, with some cineol. Chequen belongs, therefore, to the Eucalyptus series of aromatic drugs, its action being specially upon the respiratory mucous membrane, through which the oil is largely excreted. Its use is as a tonic expectorant, particularly in catarrhal conditions. It is commonly given in the form of the fluid extract, in doses of 4 to 8 c.c. (fl. 3 i.-ij.). Henry H. Rusby. CHERRY, WILD.—Prunus Virginiana. “The bark of Prunus serotina Ehrhart, collected in autumn” (U. S. P.). The bark of Prunus Virginiana L. should not be collected. It is the choke-cherry and is mostly only a shrub. This contradiction will probably be corrected in the next edition of the Pharmacopeia by dropping the word “ Virginiana” from the title. P. serotina is a large, graceful tree, with spreading, slender branches covered with red or purplish, smooth, shining bark; that of the trunk, however, is dark and exfoliating. Its wood is the valuable cherry, so exten- sively used for house-finishing and cabinet work. In general aspect it resembles the domestic cherry trees, but is much larger and hasa rounder and more spreading top. The flowers are small (less than 1 cm. across), and. borne in long, slender, rather erect, terminal racemes. Calyx cup-shaped, five-toothed. Corolla, of five-reflexed, broadly obovate white petals. Stamens, twenty or so: perigynous. Ovary, simple, one-celled, two-ovuled. Fruit, a round, black, bitterish-sweet drupe, nearly 1 cm. in diameter. Stone, one-seeded. The wild cherry tree grows in nearly all parts of the United States and Canada. In the Middle States, and in some of the Western ones, it is very abundant and large; in the extreme South it is less common, and in New England, although common, it does not attain its maxi- mum size. Wild cherry has been recognized by each edition of the Pharmacopeceia, from the first, in 1820, to the present. Although occasionally employed in Europe, it is essen- tially a local drug. : The bark should be collected in the autumn, when its. hydrocyanic odor and taste are the most perceptible, and that of the root, moreover, is said to be preferable to: that of aérial portions; but it is an abundant and cheap: drug, largely called for in domestic and other informal: 803. Chest. Chest, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. medicine, and apparently indiscriminately gathered. Much of it is nearly devoid of its proper odor. The Pharmacopeia description is as follows: “In curved pieces of irregular fragments, one-twelfth of an inch (2 mm.) or more thick, outer surface greenish brown, or yellowish brown, smooth, and somewhat glossy, marked with transverse scars. If collected from old wood and deprived of the corky layer, the outer surface is nut- brown and uneven; inner surface somewhat striate or fissured. Upon maceration in water it develops a distinct bitter-almond odor; its taste is astringent, aromatic, and bitter. The bark of the small branches is to be rejected.” The spurious bark of the choke-cherry is much thinner and tougher, consisting largely of bast fibres, which are lacking in the genuine. Wild-cherry bark contains substances analogous to the emulsin and amygdalin of bitter almonds. Upon being macerated in water and subjected to distillation it yields hydrocyanic acid, and a volatile oil having the properties of that of almonds. It also contains tannic acid. Wild cherry is used as a sedative bitter tonic and a sedative expectorant; the sedative property due to its hydrocyanic acid, the bitter probably to its amygdalin only. It is somewhat astringent. The above qualities express its entire value as at pres- ent understood. As a substitute for quinine it is entirely obsolete. Dose from 2 to 4 gm. (3ss. ad i.). The fluid extract (Hatractum Pruni Virginiane, strength 4+) and the infusion (Infusum Pruni Virginiane, strength zé5) are official, and represent it well. The syrup (Syrupus Pruni Virginiane, U.S. P., 15 per cent.) is frequently used as a basis for cough mixtures; its taste is rather pleasant. ALLIED PLants.—See Almonds, Bitter and Sweet. AuLIED Drues.—Cherry-laurel leaves, Peach seeds, and also Almonds and Hydrocyanic Acid. W. P. Bolles. CHEST, DEFORMITIES OF THE.—The chest is a box or cage enclosing and protecting the heart, lungs, and great vessels; but it is also an organ, which by its rhythmical expansion and contraction plays an impor- tant part in the respiratory act. It consists of the tho- racic skeleton and of the soft parts covering it; but the position of the clavicles, scapulse, and shoulders is so closely related to the shape and development of the chest as to require some discussion in this article. The size, shape, and mobility of the chest vary with the race, age, sex, development, occupation, and idiosyn- crasies of the individual, and it is as difficult critically to define its normal limits as it is those of the nose, ear, or any other organ or part. It is often impossible to say when normality becomes peculiarity, or peculiarity de- formity. According to Vierordt,! one expects to find in a well- constructed thorax, bilateral symmetry, slightly marked supraclavicular depressions, and a barely recognizable prominence at the junction of the manubrium and corpus sterni. The true ribs should so leave the sternum that there is increasing obliquity from above downward, making the angle between their free borders almost a right angle. The thorax should be well developed, and the scapulee should lie flat upon the back; only the lower in- tercostal spaces should be visible. The dimensions of the chest should be proportionate to the size and develop- ment of the body, and inadult life its transverse diameter should exceed its antero-posterior in the ratio of three to two or less. Vierordt’s Tabellen® give various chest measurements according to the most reliable observations. The mean value of chest play, or the difference in chest circumference between inspiration and expiration, is thus given as three or four inches. According to Lee,* the average expansion of eight hundred United States re- cruits was three and four-fifths inches. Departures from the typical standard are very frequent, and may be quite marked in perfectly healthy persons. The two sides are rarely perfectly symmetrical; indeed, Vierordt himself says in another place that in right- 804 handed people the right semicircumference of the chest is the larger by .5 to 2.cm.; in the left-handed, on the contrary, the left semicircumference of the chest is equal to or but slightly greater than the right. The chest may be small above and wide below; the angle of Louis may be more than usually prominent, and the epigastric angle exceptionally acute. The supraclavicular fossee may be marked, without disease; but if they are unequal, apical tuberculosis may be suspected. Certain ribs, as the sec- ond, third, and fourth, may project in front, or the lower ribs may be depressed. All these peculiarities are more or less atypical without being exactly abnormal. The broad chest of man with the square shoulders, and scapulz placed posteriorly, correlated with the upright posture and pendant, but freely mobile and active arms, is one of the most characteristic and striking peculiarities of the human skeleton. According to Hutchinson;‘ this position of the scapule is a very important factor in the development of respiratory power. Human respiration is, or should be, bellows-like, the fixed flap being the spine and posterior chest wall, rather than piston-like, as it often is in cramped or rigid chests. In the human embryo at the fourth month the quadru- pedal or deep chest, with the antero-posterior diameter exceeding the transverse, still persists; at birth these diameters are nearly equal. The infant is round-chested and round-bellied, and only after three or four years of age do the chest and abdomen begin to assume the more flattened shape characteristic of adult life. Inadult man the proportions of the chest are the reverse of those in the quadruped, the transverse exceeding the antero-pos- terior diameter in the ratio of three to twoorless. Of the quadrupeds only certain monkeys, moles, and bats, all animals possessing great power and freedom of motion in the anterior extremities, have broad chests. The evolu- tion of the human chest may be arrested before it is com- plete, either from congenital defect in growth or vigor or from faulty habits in childhood; we then get a long, rounded chest, a degenerate or rudimentary type, and one often associated with other defects, as will be pointed out in the sections on the phthisical chest and on round back. Chest deformities may be divided for convenience of discussion into four groups:® the congenital; those due to static conditions, whether pathological or not; those due to external constriction or pressure; and those due to conditions of the internal organs. Deformities of the chest due to violence, to new growths, to local disease, or to double or non-viable monstrosities, are beyond the scope of this article. I, CONGENITAL DEFORMITIES. The individual bones of the chest may be imperfect or wanting, fissured, misshapen, or augmented, and the thoracic skeleton may be deformed as a whole. Spine.—The thoracic spine, like the cervical and lum- bar, may contain too many or too few vertebre. Dwight ® states that since he has been looking for such anomalies, he has found them with surprising frequency. The commonest anomaly of number in the dorsal region is to have eleven or thirteen vertebre present. Noble Smith? quotes a case in which four and one-half thoracic vertebra were absent, namely, the right half of the third, the fifth, the sixth, the eighth, and the ninth. There were only .two cervical vertebre present in this case. Wedge-shaped half vertebree on one side or the other, as in the above case, are not extremely rare; or a vertebral body may be made up of two unfused halves. The arches may be incomplete—spina bifida,—a condition which may extend toa great part or the whole of the spine, and is then called rhachischisis, with which, as with ordinary spina bifida, protrusion of a sac and various anomalies of the soft parts frequently occur. In these cases various abnormal and often extreme bendings and curves of the spine and accompanying chest deformities are often seen. The best recent article on rhachischisis is that by Thorn- dike.® REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chest, Chest, It is well for bone specialists to remember, and prob- ably for others to forget, the possibility of anomalies in number when counting vertebre in the living subject; also that one or more spinous processes may be bifid, or project to one side or posteriorly without pathological significance. Sternum.—According to Dwight,® the sternum is about 9.5 per cent. of the total height for men and about nine per cent. for women. It may be entirely or partially absent, or more or less fissured longitudinally or per- forated. These defects, like the unclosed arches of a spina bifida, are due to the failure of the primitive layers to unite in the median line. When large the gap is cov- ered by a membrane; when small it may be entirely un- noticed during life. Holes, fissures, and defects are more common and of greater extent toward the upper part of the sternum. The xiphoid is often deflected, split, or perforated. Ribs.—Supernumerary ribs may occur, especially in the lower cervical and upper lumbar regions. Cervical ribs on one or both sides may sometimes be palpated at the root of the neck during life, and may cause trouble by pressure on the brachial plexus and require removal. In these cases the pleural sac may rise abnormally high, and has been opened (Planet *). Ribs may also be absent or rudimentary. Hurtlet!° reports five cases of rudimen- tary first ribs in English, and Helm! sixteen cases in general surgical literature. Cases occasionally occur in which several ribs on one side with their costal cartilages are imperfectly developed and fail to meet and unite with the sternum, or in the case of the lower ribs with the cartilage above, by varying intervals. They may end near the sternum or free border, below the axilla, or farther back, leaving a depression or furrow of greater or less extent to one side of the sternum, or in the lateral chest wall, covered only with skin and membrane, which may rise and fall with respiration, pulsate with the heart beats, and through which the underlying organs may be palpated. Through this unprotected area the lung may protrude, or if in the precordial region an ectopia cardis may take place. When such a tendency exists the gap Fig. 1247.—Osborne’s Case of Defect of Ribs. (From Haynes.) should be protected by a celluloid, hard-rubber, or metal plate, and pulmonary hernias have been known to recede under such treatment, or to disappear spontaneously. These defects of the skeleton of the chest wall are due to an arrest of growth of foetal structures, which fail to join by a larger or smaller interval. The following cases are cited as examples of this de- formity : Abercrombie’s !? case was a boy of two months, with absence of the second and third costal cartilages, left side; the corresponding ribs ended free, leaving a small unpro- | Giw Se Yi Fic. 1248.—Haynes’ Case of Defect of Lower Ribs on the Left Side. (From Haynes.) tected space. The fourth rib lay near its cartilage, but was not joined to it. There was a notch on the left side of the sternum near the third interspace. Bennett’s !* case was that of a man who died suddenly after an injury. The autopsy disclosed a defective third rib, right side, which failed to reach its cartilage by a considerable interval. This case and another reported by Bennett emphasize the danger of mistaking certain con- genital chest deformities for the effect of injury, recent or remote. Osborne’s 4 case was a boy witha triangular depres- sion on the left side of the chest due to defective devel- opment of the second, third, and fourth ribs, which were separated from their cartilages by a considerable interval. The extremity of the fourth rib was joined to the fifth costo-cartilaginous articulation. In Townsend’s" case the ribs of the left side, except the first two, were represented by short rudimentary processes. Lallemand’s '* case was a man with a depression as big as a fist on the left side of the chest, due to a deficiency of the third, fourth, and fifth ribs. Harold’s '7 case wasa backward boy of seventeen years, whose costal cartilages in the left side below the fifth rib were missing; at this level the left half of the sternum and xiphoid were deficient, and the pericardium was pro- tected only by soft parts. Homer Gage !8 reported a case of congenital absence of the sixth, seventh, eighth, ninth, and tenth ribs, left side, ina girl of seventeen years. There was severe lateral curvature, convexity to the right, with severe deformity of the chest, and a protrusion in the unprotected area, supposed to be due to a hernia of the stomach. The heart was displaced to the right, though the viscera were not transposed. In Hayne’s!* case the cartilage of the seventh rib, left side, ended three-fourths of an inch from the sternum, and the seventh, eighth, and ninth cartilages were not joined, but ended free. ; Sometimes the costal defect is accompanied by total or partial absence of the greater and smaller pectoral muscles of the same side, as in the case reported by Levy,*? in which the third and fourth ribs of the right side ended below the axilla, leaving a marked depression. There was a well-marked lateral curvature with convexity toward the right. 805 Chest, Chest, Schlesinger *! has shown that congenital absence of the pectoral muscles is frequently associated with defects of ribs or other thoracic anomalies, and cites the case of a man of twenty-two years who had in addition to a de- fect of the third, fourth, and fifth ribs, and of the costal portion of the pectoral, a congenital elevation of the shoulder—Sprengel’s disease—ail on the left side. It would seem that defects in the costal apparatus are more common in males and on the left side, that they are fre- quently associated with other thoracic anomalies, and that they sometimes occur in individuals otherwise or generally defective. Other thoracic deformities sometimes accompany con- genital malformations of the heart; there may be in such cases a projection or gibbosity of the front of the thorax above the xiphoid, “thorax en proue,” or “thorax en caréne,” or the thorax may be prominent in front with flattened sides (see Charrin and Le Noir *’). Occasionally there is a fusion of ribs, usually the first two, which are then sometimes called a bicipital rib. Other ribs may be fused at one or more points (Deutsche Chirurgie **). Stiller’s Costal Stigma — Costa Fluctuans. — Stiller maintains that the majority of cases of enteroptosis begin in youth and are associated with abnormally movable tenth ribs. This mobility may approximate that of the two lowest pairs of ribs, and is due to a congenital and possibly inherited defect in the cartilage, which joins the tenth ribs with the cartilage above. Heclaims that enter- optosis and nervous dyspepsia are identical, and that children exhibiting the costal sign will always go on to have enteroptosis, atony of the stomach, constipation, and nervous dyspepsia or dyspeptic neurasthenia. He finds these conditions nearly as common in men as in women, and concludes that tight lacing and pregnancy have but little to do with enteroptosis. Absence of the Pectoral Muscles.—This deformity occurs more frequently on the right side, and may involve both the large and small pectorals, but the pectoralis minor and the clavicular portion of the former often escape. The affected side of the chest hasa flattened or excavated appearance, but the patient has full use of the arm and suffers no inconvenience, and may even be a good soldier or gymnast. An infant six weeks old with absence of the costal portion of the left pectoral was exhibited by the writer to the Orthopedic Section of the New York Academy of Medicine in January, 1898, and by a singu- lar coincidence a boy of sixteen years with the same de- formity on the right side was shown at the same meeting by Dr. Royal Whitman. In these cases there are usually certain anomalies of the neighboring soft parts such as deficient subcutaneous tissue, scanty hair over the af- fected area and in the axilla, imperfectly developed mam- . milla, breast, and anterior axillary border of the affected side. In certain cases defects of ribs and anomalies of the scapula may exist, as in a case reported by the writer,*> and one described by Schlesinger,*! who has col- lected one hundred cases of pectoral defect from medica] literature, and who states that in about one-quarter of the cases the pectoralis minor is alsa absent; in one-tenth of the cases there is considerable anomaly of the thoracic skeleton, and in one case in twenty or twenty-five there is pulmonary hernia or displacement of the heart. Tunnel Chest, Funnel Breast, Trichterbrust, Thorax en Entonnoir.—This deformity is one of the most inter- esting of the congenital chest deformities, and has at- tracted considerable attention since Ebstein’s*® paper appeared in 1882, though the condition had been previ- ously described. Stedman?’ gives the earlier references, In these cases there is a considerable depression involv- ing the lower portion of the sternum, and the adjacent cartilagesand ribs. This depression may be large enough to contain a man’s fist, and is usually congenital, but its etiology is obscure. Some authors suppose it to be due to a defect in development, others to the pressure of the foetal chin or heels. Certain authors regard it asa stigma of degeneration, as it has been found in the insane, epi- leptic, and neuropathic; others have observed it in robust 806 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. and well-developed individuals. It occurs more fre- quently in men; out of thirty cases twenty-three were males. Arneill 8 reports six cases, of which five occurred in one family. These were a student, his brother, father, and two paternal uncles. This patient was twenty-five years old, six feet tall, and weighed one hundred and seventy-four pounds; he was well developed and in ex- cellent health. In his case the antero-posterior diameter of the thorax was, at the right nipple 17.5 cm., at the left 16.8, and at the depression in the median line 11.4. The greatest depth of the depression was 6.5cm. In the brother the depth was 4.7, and in the father 3.75. There was one sister who was free from defect. Of Klem- perer’s®® three cases two were brothers. The writer has recently reported the cases of a mother and daughter. A number of cases of acquired funnel chest have been reported. The deformity may be acquired by traction from within, from adhesions, or bronchiectasis, or by’ pressure from without, as in certain occupations. An excellent account of this and other chest deformities may be found in an article by Marie.*° As already noted, there is little or no interference with function, and some in- dividuals are able to take violent exercise, as respiratory capacity does not seem to be diminished. Ebstein ?° has described some cardiac displacement upward and to the left. Thorax en Gouttiere. —Somewhat similar to funnel chest is the “thorax en gouttiére ” of Féré and Schmidt, *! where the sternum forms the bottom of a longitudinal trough or gutter whose sides are the incurved costal car- tilages. These authors claim that ten per cent. of epileptics show this deformity. Clavicles.—The clav- icles may be wholly or partly absent on one or both sides. In par- tial absence it is usually the outer extremity which is wanting. The shoulders drop forward and inward, and may even be made to meet in front, but there is surpris- ingly little interference with function. The writer’s clavicle splint * may be used to keep the shoulders in position, acting on the principle of artificial clavicles. Congenital Hlevation of the Scapula—Sprengel’s Disease. —This condition was first described by Sprengel in 1891, and is not yet thoroughly understood. An excellent dis- cussion of the subject may be found in the recent paper by Nové-Josserand and Brisson,*4 who report twenty cases in literature and their own observation of a girl of nine years with the right scapula 3 cm. higher than the left. Besides being elevated the scapula was rotated so that the inferior angle was nearer the spine, and the spine of the scapula pointed downward and outward. The upper border of the scapula pointed upward into the neck, producing a noticeable deformity. The right scap- ula was somewhat smaller than the left, but the clavicles were equal. The movements of the shoulder joint were free, but the arm could not be raised as high as on the opposite side. The muscles responded normally’ to elec- tric stimulation. The above description is typical, and applies to most cases. In about half the cases there is a Fig. 1249.— Funnel Chest. (Arneill’s cases. ) REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chest, Chest, slight scoliosis, of which the convexity may be from or toward the affected side. In some cases there is facial asymmetry, the side of the elevated scapula being the less developed. There is little disability, sometimes none, and when treatment is required remedial gymnastics are sufficient. The writer *° has reported a case of small scapula with absent pectoral muscle on the right side. This case seems to belong in this group, though the elevation of the shoulder was slight. A peculiar form of congenital high shoulder, in which the scapula was joined to the spine of the seventh cervi- cal vertebra by a bony process, has recently been de- scribed by Wilson and Hugh.* Congenital Scoliosis.—This deformity involves more or less all the bones of the thorax. The cases in which lat- eral curvature is congenital are rather rare, though Marie *° thinks that many cases of lateral curvature which de- velop in childhood may be due to congenital defects of the thorax or spine, which remain latent or without visi- ble effect for years, but finally produce a visible curva- ture. He includes such cases under the term “déforma- tions thoraciques congénitales tardives.” In a recent study Hirschberger * attributes a certain number of cases of congenital lateral curvature with defects of the spinal column to intra-uterine pressure, with scanty amniotic fluid. Another group is associated with other anomalies, showing a widespread developmental fault. A few cases only are due to paralysis. The chest deformities associated with lateral curvature will be more fully described in a subsequent section. II. AcqurRED DEFORMITIES. (a) Chest Deformities Due to Statie Conditions.—This group comprises the chest deformities due to the various forms of lateral curvature of the spine, weak and round Fig. 1250.—Chest Deformity in Severe Scoliosis. back, to spondylitis, and in part to certain constitutional diseases affecting the bones, such as acromegaly, osteitis deformans, and spondylitis deformans. Lateral curvature of the spine, or scoliosis, is the name of a striking symptom, whose causation varies widely in different cases, and in many isexceedingly obscure. The list of diseases and conditions with which lateral curva- ture is more or less frequently associated is a long one, but in all the efficient cause is an asymmetrical or uni- lateral weakening of the skeleton or muscles, often due to aone-sided incidence of stress, as an habitual faulty or one-sided posture, loss of an arm, short leg, congenital defects of spine or chest, torticollis, Sprengel’s disease, sacro-iliac disease; in other cases to asymmetrical soft- Fig. 1251. — Antero-Posterior Chest Deformity in Severe Scoliosis. The posterior boss is on the right side only. ening, hardening, or distortion of certain parts of the skel- eton as in rickets, cretinism, achondroplasia, acromegaly, diffuse hy perostosis (leontiasis), osteomalacia, rheumatism, spinal osteo-arthritis, osteitis deformans (Paget’s disease), pulmonary osteo-arthropathy, and often tuberculous spon- dylitis; also in certain nervous and paralytic disorders which affect the spinal and trunk muscles in an asymmet- rical manner, such as poliomyelitis, sciatica, Friedreich’s ataxia, syringomyelia, hysteria, athetosis, paralysis of certain spinal muscles, and some of the chronic muscular atrophies and dystrophies. The commonest and most im- portant class, however, is that in which the lateral curva- ture is attributed to muscular weakness and habitual faulty postures, but in which no very obvious predis- posing cause is evident and about the causation of which very little is really known. The distortion of the spinal column is probably the most important but by no means the only element in the deformity. The entire thorax becomes by degrees warped and twisted, and while the different varieties of lateral curvature vary in their characteristics, and the ordinary or postural deformity in the degree of distortion finally reached, it is not too much to say that the severer grades are among the most distressing, and, unfortunately, the most common of severe chest deformities. In many cases the distortion or debility affects not only the trunk, but the pelvis, head, and extremities. , The spine usually has a dorsal and a lumbar curve in opposite directions. The convexity of the dorsal curve is to the right in a large majority of cases. The spine is also twisted on or near its axis in the same direction in which it curves, owing to its lying free from support in the thoracic and abdominal cavities: the line of the ver- 807 Chest, Chest, tebral bodies thus comes to be much more curved than the line of the spinous processes—in other words, the de- formity is much severer and more complicated than it appears to be from external inspection. After the de- formity has lasted some years, the bodies of the vertebrae become wedge-shaped and twisted, the intervertebral discs compressed, and the deformity becomes fixed. The development of this spinal distortion has a profound ef- fect upon the shape of the chest, which becomes shortened in height, reduced in most of its measurements, and is rendered stiffer and less flexible. The ribs on the side of the dorsal convexity become more bent at their angles, making a projection under the corresponding scapula; this projection is sometimes very prominent, producing a large posterior bosse. The ribson this side are more sep- arated at the sides and in front and become broader, but are crowded together behind, where they may form false articulations with the spineand with each other. On the concave side the ribs become straighter and narrower, and there is a flattening or depression in and below the scapular region. The scapula is usually-lower and less prominent on the side of the dorsal concavity, higher and more prominent with projecting inferior angle on the convex side. With aright dorsal convex curve, the left side of the thorax is prominent in front, and the left breast and left free margin of the ribs protrude; the diag- onal from right back to left front is much longer than normal, and exceeds all other horizontal measurements; the opposite diagonal is much shortened, and a horizontal transverse section of the chest shows an irregular ellip- soid, lying in the direction of the long diagonal. Both lungs are cramped, the right the most, breathing capac- ity is much diminished, the heart is displaced to the left, and the abdominal and pelvic organs are crowded. The direction of the sternum is changed, and the whole thorax and trunk are strangely shortened and twisted. It is strange that chronic pulmonary disease is so seldom met with in these severe cases of lateral curvature. They are, however, not strong, and do suffer from their deficient respiration and imperfect circulation in a delicate organ- ization, poor blood, and defective nutrition. Satter- thwaite *? has specially studied the displacements of the heart due to lateral curvature, and Faber ** the respira- tory difficulties. , The foregoing description may serve to indicate the principal characteristics of the chest deformities accom- panying the commonest form of lateral curvature. In the lateral curvature due to morbid processes affecting the osseous system, the bones of the chest will present, besides the deformities of lateral curvature, those due to the special morbid process, such as softening, hypertro- phy, or local distortion. In paralytic lateral curvature there is less rigidity, and there may even be increased flexibility, and paralysis of certain muscle groups will be found. For thesymptomatology and treatment of lateral cur- vature, and for its effects on other parts of the body, the reader is referred to other sections of this work. Chest Deformities Associated with Paralytic Affections. —The commonest is lateral curvature and its accompany- ing thoracic distortions as mentioned in the preceding paragraph, and the commonest variety of paralytic lateral curvature is that associated with a certain number of the severe cases of acute poliomyelitis, in which the trunk or spinal muscles are asymmetrically involved. In the progressive myopathies of the scapulo-humeral type, and of the facio-scapulo-humeral type, and in pseudo-hypertrophic paralysis, there often occurs, ac- cording to Marie,*° a flattening of the upper part of the thorax. Atrophy of the pectorals in connection with this deformity causes the upper part of the chest in front to have an excavated aspect. In some cases this depression is found in the lower part of the chest giving an appear- ance similar to funnel chest, and these deformities may be combined with scoliosis. Certain of these atrophic affections produce a wasp figure, the obliquity of the ribs being increased, and the chest being straight at the sides and cylindrical, with a marked depression or constriction 808 changed, the feet REFERENCE -HANDBOOK OF THE MEDICAL SCIENCES. between the lower ribs and the thoracic crests, owing to atrophy of the waist muscles. Round back, kyphosis, round shoulders, stoop shoulders, are faulty postures or deformities, in which the head, shoulders, and upper chest fall or sag forward, from im- proper poise and muscular weakness. The result is a rounded back, and consequent changes in the shape of the chest, position of the head and shoulders, and, indeed, a general fault of attitude, a de-energized position in which the principal stress is shifted from the muscles to the ligaments. There has been considerable confusion in the nomenclature and in the description of this affection, or rather symptom. Round shoulders is a term in com- mon use, but is unsatisfactory since the faulty position of the shoulders is a secondary symptom, largely due to the shape of the back and chest, for which reason the term round back is preferred by the writer, though this term also fails to indicate the general disturbance of poise which is usually present. The term kyphosis is unfortu- nate, since it is also used to designate the deformity due to Pott’s disease of the spine, from which it is exceedingly important to distinguish it. Round back or weak back, then, is that position of re- laxation into which the body falls when the upper trunk is no longer held up by weakened spinal muscles. Ex- cluding the angular projection of Pott’s disease, which becomes rounded only in the latest stages, the affection may be divided into several varieties, namely, those due to: (1) Imperfect development of the chest; (2) congeni- tal or acquired weakness—convalescence; (3) oldage; (4) paralytic affections; (5) certain diseases which affect bone and general nutrition, such as rickets, scurvy, cretinism, spondylitis deformans, osteitis deformans (Paget’s dis- ease), acromegaly, pulmonary osteo-arthropathy. The list is very similar to that given for scoliosis, but whereas in that case the bony or muscular support was weak- ened on one side, in this the weak- ening is approxi- mately symmetri- cal. Most of these kyphotic conditions have in common the forward sagging of the spine for lack of bony or muscular support or both. The head and up- per chest fall for- ward, the spine be- comes more or less rounded, the chest becomes compress- ed at its upper part, but may be- come narrower rather than flatter as a whole; the ribs drop down- ward, the shoulders and scapule down- ward and forward, their inner borders receding from the spine and their in- ferior angles be- coming more prom- inent. The posi- tion of the pelvis is (Original. ) Fic. 1252.—Severe Round Back. are weak or flat and everted, and there is a tendency to knock-knee. The chest is usually less flexible than normal, respiratory capacity and power are diminished; there is often a trans- verse furrow at the upper border of the abdomen. The attitude is that of fatigue, weakness, debility, relaxation. It is doubtless an attitude which may be produced or REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. intensified by habitual faulty positions, such as those as- sumed for many hours daily by school-children or clerks at their desks. This factor, however, must usually be associated with fault of structure or inherited or acquired vice of nutrition, muscle tone, or skeletal resistance, in order to be effective. It is to be noted that the non- pathological form of round back often affects children as early as the fourth or fifth year, and that, as already re- marked, it is rather a general than a localaffection. Weak and pronated feet, week eyes, and slight degrees of lat- eral curvature often accompany it. These children are often physically delicate and mentally unstable. They may inherit an imperfect physique, or their life is so precocious or intense, as to interfere with ample and sym- metrical development. In other words, a good many of these children are degenerates or bordering on degen- eracy, and present the rounded back and drooping shoul- ders as striking symptoms, but usually show other un- mistakable signs of imperfect development. Tbe writer believes that in a certain proportion of these round-backed children, the evolution of the chest has been retarded or arrested atacertain stage either from inherited tendency or from causes acting in early childhood, irrespective of faulty attitudes, and that this rudimentary chest stands in close relation with the pre-tuberculous type of chest described by Hutchinson. It is probable that ina certain class of cases the faulty attitude is in large measure de- pendent on the long, narrow, and deep chest, which favors drooping shoulders and abducted scapule, and to the instinctive desire of the delicate, under-nourished, and over-stimulated child to shift the strain of bodily weight from the tired muscles to the insensitive liga- ments. It follows that purely local treatment rarely fulfils the indications, and that management with a view to general development and a proper regulation of the life is of pri- mary importance. The chest should be amply developed in early years by a free, open-air life, with plenty of tree and hill climbing, romping, rambling, swimming, run- ning, and ball-throwing, sports that involve well-distrib- uted and vigorous exercise, and especially develop arm action and respiratory power. The habits should be regulated and over-stimulation avoided. When the chest deformity is pronounced, spe- cial corrective and gymnastic exercises are of great ben- efit. Remembering that the faulty attitude is general, it is often necessary to begin by strengthening, placing, and shoeing the feet, in order to secure a correct pose. Thus the pupil should be drilled in the proper poise of the body, chest forward and up, abdomen and hips back, weight on balls of feet. After these matters have been attended to, breathing and corrective exercises may be successfully applied to the chest. Supporting apparatus is seldom, and shoulder straps are never, required. The senseless admonition to throw the shoulders back without attention to these preliminaries would be productive of much harm if it were not almost invariably disregarded. The round back of certain occupations and of conva- lescence are varieties of the round back of weakness. The round back of old age isaccompanied by changes of form | in the chest similar to those described. It is due to the gradually increasing muscular weakness and ligamentous rigidity due toadvancing age. Thespinal muscles, whose tonus is diminished, no longer suffice to hold the spine erect and the chest free. The drooping spine compresses the intervertebral discs anteriorly; their elasticity is im- paired, and the false attitude finally becomes fixed. The only efficient prophylactic is an active and well-distrib- uted muscular life in youth and manhood with thegvoid- ance of debilitating influences. In round back due to paralytic disorders the spine is often extremely flexible, though respiratory power is diminished from muscular weakness. The chest often remains collapsed, and the breathing may be abdominal. The management is usually that of the disorder upon which the round back depends. Special exercises and supports are sometimes of service, and the writer has found the prone position on an inclined padded board or Chest, Chest, mattress to have an excellent influence in stimulating the spinal erector muscles to action, and in correcting the deformity. The round back of paralysis agitans is similar to that of old age. The round back or so-called kyphosis of rickets, infan- tile scurvy, cretinism, and marasmus usually comes on in Fig. 1253.—Rounded Kyphos of Cured Pott’s Disease. (Original.) infancy before the child is able to walk, and consequently before the evolution of the normal antero-posterior curves of the spine. The sitting posture probably has much to do with its production, and the projection is of a different character from that described in the first part of this section. It is rounded and situated in the middle or lower part of the back, though it may involve nearly the whole spine, which is more or less flexible and free from muscular spasm; there is no characteristic pain. It dif- fers in all these respects from the kyphosis of spondylitis, with which it is sometimes confounded, and which it is exceedingly important to differentiate. Mechanical sup- port is rarely required, as the deformity usually recedes under recumbency for longer or shorter periods, together with the treatment appropriate for the dyscrasia. In the rare cases in which the deformity persists and becomes rigid after the cure of the disease, the treatment is difficult, and mechanical support may be required. In acromegaly the dorsal spine may become rounded, and the ribs, sternum, and clavicles hypertrophied, giv- ing a massive, deep chest. The bent back and exagger- ated senile attitude may occur in osteitis deformans (Paget’s disease) and in osteo-arthritis of the spine. Angular Kyphosis.—In Pott’s disease the integrity of the spinal column is destroyed by local tuberculous ulcer- ation, and the upper section of the trunk falls forward until it finds support, giving rise to a kyphos, or hump of the back, which is at first always angular, and to vari- ous changes in the shape of the chest, especially if the disease affects the thoracic vertebree. In disease of the upper dorsal region the upper part of the chest is flat- tened in front. In disease of the mid-dorsal region the ribs become more sloping, in severe cases resting on the 809 Chest, Chest, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ilium or within the pelvis; the chest becomes shortened and laterally compressed ; the sternum and lower ribs be- come prominent, and the antero-posterior diameter of the chest is increased. The chest also becomes very rigid, and the breathing abdominal and accelerated. The changes in the shape of the chest take place very slowly, and are only fully developed after several years. Therearealways rigidity and spasm of the spinal muscles during the act- ive stage, and often restless- ness or crying at night, ab- dominal pain, and a character- istic attitude. These points and others differen- tiate it from the rachitic spine al- ready described. The treatment is that of Pott’s disease, which includes atten- tion to hygiene and. nutrition, long - continued spinal support by special appli- ances, the avoid- ance of exercise, and more or less recumbency. The Rachitie Chest. — Besides lateralcurvature and kyphosis there are other deformities of the chest so frequently found in rickety children as to merit separate mention. Harrison's Groove.-—The greatest softening in the ra- chitic chest takes place in the cartilages of the lower ribs, where the chest is unprotected by the lifting action of the upper and lateral chest muscles. Just below the nip- ples there is nearly always a depression, which in severe cases extends upward near the costo-sternal junction or outward toward the axillary line. It has often been thought that this depression was due to the traction of the diaphragm, but it lies above the diaphragmatic at- tachment. The free border of the ribs is usually promi- nent, owing to enlarged liver and spleen and distended abdomen. These lateral depressions of the chest are in such a position that they are comfortably filled by the flexed forearms of the child, but it is improbable that the pressure of the arms has anything to do with their pro- duction. According to Stone,*® flattening of the sides of the chest is less common than the formation of a trans- verse groove and occurs in about a quarter of the cases. The enlar gement of the costo-chondral junctions, which forms the rachitic rosary, is often so great as to be plainly visible. Pigeon Breast, Pigeon Chest, Chicken Breast, Keeled Chest, Pectus Carinatum. —The submammary flattening, the formation of a transverse sulcus, the flattening of the sides of the chest, and the flattening of the t pper anterior chest enter into the formation of pigeon breast, which is simply the final outcome of a process of which the flat- tening is the first stage (Stone). In pigeon chest the sternum, and especially its lower part, is prominent, and the costal cartilages slope away abruptly at the sides. The antero- posterior diameter of the chest is increase, the lateral diminished, and the chest is much narrowed in front; it is also shorter than normal. The reverse condition with a depression over the ster- num may occur as the result of rickets. Both these de- Fig. 1254.— Kyphos and Chest Deformity of Cured Pott’s Disease. (Original.) 810 formities may be more pronounced on one side. These rickety chests are not only misshapen, but after the sub- sidence of the rickets they may remain unduly rigid and dwarfed. Besides impeding respiratory movements, these ra- chitic chest deformities cause very little trouble, and when fully developed are practically incurable. Ameliora- tion may sometimes be obtained by respiratory and gen- eral exercises. During the stage of development the treatment of the rickets is very important. Similar conditions are sometimes due to obstruction of the air passages by adenoids, swollen turbinates, enlarged tonsils, polypi, or hypertrophic rhinitis. Tubby *° relates several such cases, giving illustrations of the deformities produced. He says the proof of the dependence of the chest deformities upon the conditions named is given by their rapid improvement after the removal of the ob- struction to respiration. A mild grade of these conditions is not uncommon in school-children, and is often accom- panied by mouth breathing, and by inattention and ap- parent mental dulness, which clears up when the cause is corrected. (b) Chest Deformities Due to Lacing.—Certain chest deformities are due to pressure from without, and of these the commonest is the constriction of the waist and lower chest by corsets among civilized women. The use of corsets, even when loosely laced, prevents the proper expansion of the lower ribs in respiration, and forces the breathing into the upper thorax. This effect has been so universal that the exaggerated upper Fig. 1255.—Rachitic Chest, Showing Pigeon Breast and Harrison’s Groove. (Hospital for Ruptured and Crippled.) thoracic breathing of women is usually described as a normal peculiarity of the sex, but it has been pretty well éstablished that boys and girls breathe alike until the girls put on corsets, and that women who do not wear corsets breathe very much like men, that is, with | a bellows action of the whole chest, and not with a piston action of part of it. The evil effects of this ab- normal constriction are seen not only in respiration, but even more in the crowding and displacement: of the viscera. The liver may be deeply indented with the marks of the compressing ribs, and the ribs themselves REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chest, Chest. are often misshapen about the waist. The stomach, in- testines, and pelvic organs are frequently displaced downward, with many resulting ills. The rigidity and compression of the stays weaken the waist, back, and abdominal muscles, and interfere with the natural sup- port and normal mobility. Cobbler’s Chest.—Some occupations cause special chest deformities, such as the cobbler’s chest, due to the press- ure of the last against the end of the sternum, producing a depression similar to funnel chest, but lower. Tailors who sew in a bent-over attitude often have a hollow chest. (ce) Deformities Due to Changes in the Thoracic and Ab- dominal Contents.—The last division of chest deformities includes those that are due to changes in the thoracic or abdominal contents. The Inflated, Distended, or Emphysematous Thorax.— The typical chest of emphysema is large and rounded or barrel-shaped. It is, in fact, a chest which permanently retains the shape of extreme inspiration, owing to the ballooning of the enlarged and dilated lungs, or, accord- ing to Campbell,*! to overaction of the inspiratory mus- cles, the antagonistic pulmonary elasticity being impaired. The ribs are strong and leave the sternum nearly ata right angle, making the thorax appear short. The ster- num is prominent, especially at the angle of Louis, and the epigastric angle is large. The supraclavicular depres- sions are shallow or effaced; they may even be converted into elevations, if the pulmonary apices are markedly emphysematous. This is by no means always the case; they may even be deepened. The chest is immobile, and the breathing abdominal. While one may-safely infer the presence of emphysema from the rigid, inflated chest, one should not call the large, deep chest of well-built and active men emphysematous, nor should one forget that in many cases of emphysema the lungs are not enlarged, and the chest fails to present the above-described characteristics. One-sided distention of the chest, particularly in its lower part, may occur in pleuritic effusion and empy- ema of one side, in which conditions there may be bulg- ing of the lower intercostal spaces. In proportion as the breathing is crippled on the affected side, there will be inflation and overaction of the well side, especially at the upper part in front. Hypertrophy of the heart, pericar- dial effusion, and aneurism may cause enlargement in the precordial region, and marked enlargement of the liver or spleen may cause a bulging of the ribs on the corre- sponding side. Chronic distention of the stomach and bowels may cause prominence of the lower ribs on both sides. Effusions and enlargements of the internal organs will affect the shape of the chest in proportion to its flex- ibility. These deformities are therefore most marked in children, less in adults, and least often observed in the aged. In individuals with rigid chests changes in the internal organs may produce but slight effect. The Phthisical, Phthinoid, Alar, Paralytic, or Rudi- mentary Chest.—This is partly a rudimentary and partly an atrophied chest. It has usually been described as flat or flattened, but Hutchinson’? has shown that it may be not only relatively but absolutely longer, narrower,’ deeper, and rounder than normal, approximating the quadrupedal type. It is apparently a chest whose evo- lution has been arrested at a lower stage. In the chest of phthisis the ribs are depressed, and the intercostal and supraclavicular spaces may be sunken. The epigastric angle is diminished; costal breathing is lessened on the affected side. If chest development is arrested in childhood or ado- lescence, the liability to phthisis is increased, and one may infer a certain predisposition to pulmonary tubercu- losis from the existence of this chest in the young. The investigations of Gabrilowitch** confirm these views. He found that the ratio of the circumference of the best- shaped chest to the total height was as1to1.6. The ratio of the mean antero-posterior diameter to the trans- verse was as .70 to 1 in normal individuals, but in phthisi- cal individuals the proportion was .73to1. Rothschild * criticises Gabrilowitch’s methods and conclusions, and gives the ratio of chest depth to chest breadth as 1 to 1.8 in healthy individuals, and as 1 to 1.5 in phthisical sub- jects with thorax paralyticus. He gives the chest cir- cumference as one-half the total height, and the length of the sternum as one-fifth the chest,circumference in the healthy, less in thorax paralyticus. He-also states that the angle of Ludovici and the angular movement of the sternum in respiration are less in phthisis (see measure- ments by De Giovanni*). The whole subject apparently requires more exact and extensive study. During the destruction of lung tissue atrophy of the muscles of the chest takes place, and is most pronounced on the side most seriously involved, and unilateral if the disease is unilateral. Carcasonne * finds that atrophy of the scapulo-thoracic muscles takes place early and independently of general emaciation; it may even precede auscultatory signs. This atrophy is not accompanied by functional changes in the muscles, nor is their electric excitability altered; it advances with the progress of the pulmonary lesion, and is of considerable diagnostic value. The analogy of this concomitant atrophy of the muscles of related areas with the primary atrophy in joint disease is evident. In the latter case, however, the tonus and mechanical and electric excitability are said to be increased. The very great importance of an active out-of-door life, of exercise stimulating deep breathing, and of free use of the armand shoulder muscles for the round-shoul- dered and alar-chested, isapparent. Swimming, running, climbing, and throwing are particularly indicated. Unilateral shrinking of the chest occurs in phthisis of one side. The deepening of one supraclavicular fossa is an evilsymptom. Overashrunken cavity the chest may present a depressed appearance, with hollow intercostal spaces. From the atrophy already mentioned, as well as from the traction of adhesions, there may be depression of the chest wall without cavity. After pleurisy and empyema, if the lung does not expand, the affected side of the chest may become markedly shrunken, and the whole thorax deformed with a scoliosis, whose convexity is toward the well side. Henry Ling Taylor. BIBLIOGRAPHICAL REFERENCES. 1 Medical Diagnosis, Philadelphia, 1898. 2 Anatomische, physiologische, und physicalische Daten und Tabel- len, Jena, 1893. 3 Medical Record, July 29th, 1899. 4 Journal American ‘Medical Association, September 1st, 1897, p. 512. 5 Encyclopedia Medica, Edinburgh, 1899. § Medical Record, September 8th, 1894. 7 Clinical Sketches, London, 1895. 8 Transactions American Orthopedic Association, vol. xii., 1899. ® Thése de Paris, 1890 10 Journal of Anatomy and Physiology, vol. xxx., London, 1896. 11 Anatomische Anzeiger, 1894-95, p. 540. 12 Transactions Clinical Society of London, vol. xxvi., 1893, p. 225. 13 Transactions Academy of Medicine of Ireland, vol. i., p. 163. 14 Archives of Pediatrics, vol. viii., p. 346. 15 Boston Medical and Surgical Journal, vol. Ixxxv., p. 114. 16 Ephéméris médicale de Montpellier, 1826, p. 144. 17 Lancet, February 19th, 1898. 18 Transactions American Orthopedic Association, vol. ii., p. 233. 19 American Medical and Surgical Bulletin, November 15th, 1894, 20 British Medical Journal, May 13th, 1899. 21 Wiener klinische Wochenschrift, January 4th, 1900. 22 Cyanose et déformation thoracique. Société de Biologie, Novem- ber 8th, 1899. 23 Deutsche Chirurgie, vol. xlii., Stuttgart, 1888. 24 PAS klinsche Wochenschrift, August 28th and September 4th, 1899. 25 Pediatrics, February 15th, 1900, p. 154. 26 Deutsches Archiv fiir klinische Medicine, April, 1882, p. 411. 27 Reference Handbook of the Medical Sciences, vol. ii., p. 80, 1886, 28 Philadelphia Medical Journal, March 11th, 1899, p. 559. 29 Deutsche medicinische Wochenschrift, 1888, No. 36. 30 Gazette hebdomidaire, February 16th, 1896. 31 Journal de l’Anatomie et Physiologie, xxix., 1893, p. 564. 32 Pediatrics, December Ist, 1899. 33 Archiy fiir klinische Chirurgie, vol. xlii., p.545. 34 Revue mensuelle des maladies de l’enfance, March, 1900. 35 Annals of Surgery, April, 1900. : 36 Zeitschrift fiir orthopadische Chirurgie, vol. vii., p. 129, 1899. 37 New York Medical Journal, September 30th, 1899. 38 Jouré et Boyer, Paris, 1899. . 39 Transactions American Orthopedic Association, vol. xi., p. 337, 1898. 40 Deformities, a Treatise on Orthopzedic Surgery, London, 1896, p. 24. 41 Respiratory Exercises, New York, 1899. 42 British Medical Journal, October 28th, 1899. 43 Berliner klinische Wochenschrift, May 22d, 1899. 811 Chest, Chest, 44 St. Petersburger medicin. Wochenschrift, No. 18, May 19th, 1900. 45 Morfologia del corpo humano, Milan, 1891. 46 Thése de Paris, 1899. ; CHEST, PHYSICAL EXAMINATION, OF THE.— Physical examination of the chest is accomplished by the use of the special senses of sight, hearing, and touch in the application of the methods of inspection, palpation, mensuration, percussion, and auscultation. The phe- nomena observed by these methods of investigation are called physical signs. To recognize and properly inter- pret the physical signs caused by abnormal conditions of the thoracic viscera it is essential that the observer should thoroughly understand the normal physical signs and be able to recognize them. The physical signs obtained on examination indicate to the observer the condition of the organs examined, and from the consideration of these physical signs to- gether with the subjective symptoms and history of the patient, the diagnosis of the disease producing the patho- logical changes is made. The diagnosis should never be made from the physical signs alone. PuysicaL EXAMINATION OF THE LUNGS. Topography of the Chest.—For convenience in descrip- tion and for reference the surface of the chest is divided into anterior, lateral, and posterior regions by vertical and transverse lines. Vertical Lines.—Anterior median or mid-sternal; sternal line drawn parallel to the edge of the sternum; mid-clavicular line drawn downward from the middle of the clavicle, usually passes through the nipple in men, and is, therefore, sometimes called the mammary line; parasternal line, drawn midway between the sternal and mid-clavicular lines; anterior axillary line drawn through anterior fold of axilla; mid-axillary line and posterior axillary line drawn through middle of axilla and posterior fold respectively; scapular line drawn vertically through angle of scapula when the arm hangs at the side; pos- terior median line. Transverse Lines.—On the anterior surface of the chest Yi Osment 7] Si Fic. 1256.—-Anterior Surface of Chest. : broken line, fissures between lobes and line of pleura ; dot and dash line, stomach ; k, fissure between right middle and lower lobes. Untersuchungs-Methoden,”’ etc.) 812 y) 7) | , Continuous line, border of lungs; , dotted line, liver ; , double line, heart and great vessels. vena cava superior; C, right auricle; D, pulmonary artery; H, left auricle; F, left ven- tricle ; G, right ventricle ; ab, border of right pleural sac ; cd, border of left pleural sac ; ef, edge of right lung; gh, edge of left lung; 7, fissure between right upper and middle lobes; (From Sabli’s ** Lehrbuch der klinischen REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. transverse lines are drawn parallel to the lower borders of the third and sixth ribs, the latter of these lines pro- longed also divides the upper from the lower axillary relia) ‘ Fig. 1257.—Lateral Surface of Chest. _————, Continuous line, lower border of left lung; ------- , broken line, fissure between left upper and lower lobes, lower border of pleura; . , dotted line, spleen and liver; —--- --- , dot and dash line, stomach and kidneys; ab, lower edge of left lung ; ac, lower border of pleural sac; f, edge of left lobe of liver; g, posterior, h, anterior end of spleen (when oval in shape); k, lower edge of left kidney; n, greater curvature of stomach. (From Sahli.) settee regions; on the posterior surface lines are drawn parallel to the second rib, through the spine of the scapula, and joining the angles of the scapule. Anterior Regions. —Supraclavicu- lar, above the clavicle; clavicular, that portion of chest covered by clav- icle; infraclavicular region, from lower border of clavicle to lower bor- der of third rib; mammary region, from lower border of third to lower border of sixth rib; inframammary region, from lower border of sixth to free border of ribs; upper sternal to lower border of third rib, and lower sternal, from lower border of third rib to ensiform cartilage. Lateral Regions.—Axillary region to lower border of sixth rib; infra- axillary, from lower border of sixth to free margin of ribs. Posterior Regions.—Upper scapular, from second rib to line of spine of scapula; lower scapular, from spine of scapula to angle of scapula; in- frascapular, from line joining angles of scapule to twelfth rib; interscap- ular region, that portion of posterior surface which lies between the scap- ula and the spine. Relation of the Borders and Fissures of the Lungs to the Surface of the Chest.—Anteriorly, the apices extend from half an inch to an inch and a half above the clavicle, and _ pos- teriorly as high as the seventh cer- vical vertebra (Fig. 1259). The an- terior borders pass down behind the sterno -clavicular articulation and meet in the median line opposite the Kal ’ A, Aorta; B, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chest, Chest, second ribs. They remain in contact as far as the fourth ribs; at this point the right border passes down to the sixth rib in the median line, thence passing out- U0 = Fic. 1258.—Posterior Surface of Chest. - spleen and liver; ------- , dot and dash line, kidneys. Sahli.) ward and downward, the lower border in quiet respira- tion reaching the sixth rib in the mid-clavicular line, the eighth in the mid-axillary line (Fig. 1257), the ninth or tenth rib in the scapular line, and the eleventh rib near the spine; at the fourth rib the left border passes outward to the fifth costo-chondral junction, then down- ward and inward to the sixth rib, and then outward and downward. The lower border of the left lung is usually a little lower than the right. The Fissures between the Lobes.—The fissure between the left upper and lower lobes and between the right middle and lower lobes may be indicated by a line drawn from the third dorsal vertebra to the sixth rib in the mid- clavicular line (Fig. 1258). This line corresponds roughly with the vertebral border of the scapula when the elbow is raised and the hand placed on the head. The fissure between the right upper and middle lobes meets the fissure between the upper and lower lobes at the axillary border of the scapula and passes almost horizontally for- ward to the junction of the fourth costal cartilage with the sternum (see Figs. 1256, 1257, 1258). The right lung consists of three lobes, which bear the following relations to the surface of the chest: Anteriorly the upper lobe extends to the fourth or fifth rib, and the middle lobe from the fourth to the sixth rib. Laterally the upper lobe extends to the fourth rib, the middle lobe to the sixth rib, and the lower lobe to the eighth rib. Posteriorly the upper lobe extends from the apex to the spine of the, scapula, the lower lobe extends from this point to the base. On the left side the upper lobe oc- cupies the whole of the front of the chest; laterally the upper lobe extends to the fourth rib, below this the lower lobe to the base (Figs. 1256 to 1259). Trachea and Bronchi.—The trachea deviates in its lower part a little from the median line and bifurcates behind , Continuous line, lower border of lungs; ------- . broken line, fissures between lobes, and line of pleura; ......., dotted line, é, Fissure between left upper and lower lobes; f, fissure between right upper and lower lobes; g, beginning of fissure between right upper and middle lobes; ab, lower edge of lung; cd, lower border of pleural sac ; h, spleen; i, lower border of liver; k, left kidney; 1, right kidney. (From the right edge of the sternum at the junction of the lower border of the second costal cartilage and the sternum. This point corresponds posteriorly with a point a little to the right of the spine of the fourth dorsal vertebra. The general course of the main bronchi may be pro- jected on the posterior surface of the chest as follows: The right bronchus starts at a point to the right of the spine of the fourth dorsal vertebra and extends in nearly a straight line to a point on the eighth rib two inches to the right of the spine. The left bronchus originating at the same point, passes outward and then downward to a point on the eighth rib three inches from the median line. The calibre of the right bronchus is larger than that of the left, and this bronchus forms a more direct continua- tion of the trachea than does the left. This explains the fact that most for- eign bodies which pass into the trachea through the larynx are found in the right bronchus. The bronchi are nearer to the posterior surface of the chest than to the anterior. The position and relations of the bronchi are important and help to explain the physical signs in the inter- scapular regions, and the differences in the signs at the apices of the lungs. Diaphragm.—The dome of the dia- phragm on the right side extends as high as the fourth intercostal space in the mid- clavicular line, in the axillary line to the sixth rib, and in the scapular line to the eighth rib. On the left side the diaphragm occupies a somewhat lower position. Liver.—On the right side in mid-cla- vicular line the liver extends from the fourth space to the free border of the ribs. From the fourth space to the sixth rib the liver is separated from the chest wall by a wedge of lung tissue, below this point it is in contact with the chest wall. In the right axillary and the scapular lines the liver’s upper border corresponds with the lower border of the lung (Figs. 1256 to 1258). Fig. 1259.—Posterior Surface of Chest, Showing the Relation of the eras and Lower Limits of the Lungs to the Chest Wall. (From abli. 813 Chest, Chest, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Spleen.—The spleen lies beneath the ninth, tenth, and eleventh ribs. Its upper border follows the ninth rib, and its anterior border extends to a line drawn from the tip of the eleventh rib to the left sterno-clavicular articu- lation (Figs. 1257 and 1258). The lungs may be examined with the patient in either the standing, or sitting, or recumbent position. It is im- portant that the position be a comfortable one, and that the patient’s arms and legs are symmetrically placed. The patient should also be stripped to the waist. INSPECTION.—By this method of examination the form, the size, and the movemenst of the chest in respiration are studied, and un- der this head the investigation of the organs of the thoracic cavity by means of the a-raysS may also be included. Form.—The normal adult chest is elliptical in shape, the transverse di- ameter longer than the antero- posterior, and (Gee.) the two sides practically sym- metrical; on measurement, however, the right is usually about half an inch larger than the left (Fig. 1260). The supraclavicular regions are somewhat depressed, and there is generally a slight depression just below the clavicles; the remainder of the anterior surface of the thorax is convex from above downward and from side to side. The epigastric angle is nearly aright angle. The spine is usually straight, but may incline slightly to the right in the upper and middle dorsal regions. In children’s chests the two diameters are nearly equal, and the chest nearly circular in form. The apex beat of the heart is often visible in the fifth intercostal space about one inch inside the mid-clavicular line. As the result of disease deviations from the normal form of the chest occur; the more common of these are the rickety, pigeon-breast, phthisical or alar, emphysematous or barrel-shaped chests, and the deformities due to spinal disease. Changes in the contour of the chest may be demonstrated by means of the cyrtometer (see Cyrtom- eter). In addition to these general deformities there may be retraction or enlargement of the chest walls. Retraction or sinking in of the chest wall, generally of the intercostal spaces, may be general or local. General retraction is caused by obstruction to the entrance of air into the larynx or trachea, foreign bodies in the larynx, diphtheritic membrane, tumors pressing on the trachea. Local retraction is the result of collapse or contraction of the lung. An example of this local re- traction is seen at the apices of the lungs in phthisis, and at the bases as the result of an old pleurisy with adhesions, or of empy- ema. Enlargement or bulging of the chest wall may be localized or may involve the whole of one side. In the former case it is usu- ally due to abscess, tumor, or enlargement of the liver, spleen, or heart; in the latter to fluid or air in the pleural cavity. The location of the bulg- ing often suggests the cause. General enlarge- ment of the chest is also seen in cases of emphysema. The size of the normal chest varies greatly; the average circumference at the level of the nipples is thirty-four Fig. 1260.—Normal Chest. gore res FiG. 1261.—Rickety Chest. (Gee.) 814 inches; it may vary from twenty-eight to forty-four inches. : b, 4 Ps + af ria. ‘ ) aru 7 . ca “1 ).. “- - a 4 : 45: i » r . ' ’ an LIBRARY : OF THE UNIVERSITY of ILLINOIS. =e REFERENCE HANDBOOK OF THE MEDICAL SCIENCES, with the parietal wall. The kidneys may be mapped out with the exception of the inner border. Another form of auscultatory percussion has come into use with the invention of the phonendoscope. Here in- stead of percussing, the surface of the chest in the neigh- borhood of the organ under examination is gently scratched with the finger. This produces a sound the quality of which, as well as the intensity and pitch, in- stantly changes when the density of the organs beneath the surface changes. It is merely a modification of aus- cultatory percussion, but is perhaps capable, in skilful hands, of giving even more definite information in regard to the size of the solid organs of the body, of tumors, the level of fluid exudates or transudates, and the line of contact between tumors and solid organs, or between solid organs and fluid. As in percussing the lungs, so in the examination of the heart by percussion, much information may be gained by noting the sense of resistance beneath the finger in contact with the chest wall. If by either of the methods of percussion described the area of the heart dulness is found increased, it is suggestive of hypertrophy of the heart muscle, and the locality of the dulness indicates the portion of the heart which is enlarged; of fluid in the pericardium; of aneurism, or of a consolidated lung or tumor displacing the heart. Should the area of cardiac dulness be diminished, the usual cause will be found in an emphysematous condition of the lungs. AUSCULTATION.—By auscultation the character, rhythm, and point of maximum intensity of the normal heart sounds are observed, any changes in the intensity or rhythm are noted, and the presence of any abnormal sounds or murmurs is detected. In this examination the immediate or mediate method may be employed. The mediate is, however, the more common, and the use of the stethoscope enables the examiner to localize the area of the maximum intensity of the sounds more exactly ; it also intensifies the sounds, so that sounds inaudible to the ear may by its aid be clearly heard. Two sounds are heard on auscultation: the first, or systolic sound, occurring with the systole of the heart, somewhat dull and booming in character, and resembling the syllable “tubb”; the second, or diastolic sound, oc- curring with the diastole of the heart, short, quick, and snappy in character, like the syllable “dupp.” The first and second sounds are separated by a short pause, and a longer pause occurs between the second sound and the succeeding first sound. This rhythmical recurrence of the first and second sounds with the inter- posed pauses makes up the cardiac cycle. The first sound is produced by the closure and tension of the auriculo-ventricular valves and the tension of the walls of the ventricles; it is, therefore, a composite sound made up of several elements. The second sound is caused by the sudden closing of the aortic and pul- monary valves. Normally these sounds recur in rhythmical sequence, and may be heard all over the precordium. There are, however, areas where the individual sounds may be heard with greater distinctness. For example, the first sound may be heard most clearly at the apex, and not immediately over the point of production, the location of the mitral and tricuspid valves. This area at the apex is called the mitral area. The aortic element of the second sound is most clearly heard in the aortic area, the second right intercostal space near the sternum; and the pulmonary element in the sec- ond left intercostal space, the pulmonary area. At the apex the quality of the systolic sound is soft and boom- ing, the pitch is low, the intensity marked, and the dura- tion long. The quality of the second sound is clicking or sharp, the pitch is higher than that of the first sound, the intensity less, and the duration shorter. At the base the intensity of the first sound is dimin- ished, and that of the second sound increased. Asarule, the secoud sound is heard more distinctly in the aortic Chest, Chest, area than in the pulmonary; in other words, the aortic element of the second sound is normally the louder. Disease may cause changes in the normal heart sounds, which modifications are noted in the quality, intensity, duration, and rhythm. The quality of the first sound may be impure or rough, and there may be reduplication of the first sound, which is caused by the non-synchronous contraction of the ven- tricles and closure of the auriculo-ventricular valves. The intensity of the first sound is much increased in cases in which there is hypertrophy of the left ventricle, in acute febrile diseases, and in patients with very thin chest walls. Diminution in the intensity is noted in emphy- sema, in patients with very thick chests, in cases of peri- carditis with effusion, in all exhausting diseases, and in dilated heart. In hypertrophy the duration of the first sound may be prolonged, even to the point of sounding like a murmur; and in dilatation this sound is so shortened that it may be mistaken for the second sound. The same shortening of the first sound is often observed in cases of mitral stenosis. The rhythm is often irregular or intermittent; this is particularly marked in cases of mitral stenosis and in di- lated heart. The aortic element of the second sound, or the aortic second sound as it is called, is accentuated in any disease which causes an increase in the blood pressure in the aorta and systemic circulation; in other words, when the arterial tension is high, or when there is an increased amount of blood in the aorta, as in aneurism or dilatation of the aorta. When the action of the heart is weak, as in dilated heart, in fevers, and in myocarditis, the amount of blood and the tension in the aorta are dimin- ished, and the intensity of the aortic second sound is lessened. The pulmonic second sound is accentuated when the pulmonary circulation is under increased ten- sion; in mitral disease, either stenosis or insufficiency of the valve, and in pneumonia or emphysema. When the tension in the pulmonary circulation is low, the second sound in the pulmonary area is diminished in intensity. There is not uncommonly areduplication of the second sound, which is due to the fact that the aortic and pul- monary valves do not close at the same moment. This occurs when the tension of the blood, or blood pressure, is unequal in the systemic and pulmonary circulation. It is frequently observed in mitral stenosis. In addition to the normal heart sounds, other sounds may be heard which are the result of diseased conditions of the heart or vessels. These abnormal sounds may be produced either within or without the heart or in the great vessels, and are therefore called endocardial, exo- cardial, or vascular murmurs. In listening to a murmur, in order to decide upon its nature and the lesion upon which its production depends, it is necessary to note the time of the cardiac cycle at which the murmur is heard, its point of maximum intensity, the quality of the sound, and the direction in which it is transmitted. Exocardial Murmurs.—These sounds are produced by the rubbing together of the surfaces of the pericardium made rough by inflammation, or by the movement of the pulmonary pleura against the pericardial sac; hence these sounds are called pericardial friction sounds or mur- murs or pleuro-pericardial sounds. Pericardial murmurs occur in pericarditis, and they are heard with both the systole and the diastole of the heart. From this fact they are often spoken of as “see-saw ” or “to-and-fro” murmurs. The murmur is usually loudest. at the base of the heart and along the line indicating the auriculo-ventricular groove. The quality is rubbing and creaking, not of marked intensity and often very faint; the intensity may frequently be increased by pressure on the chest wall with the stethoscope. The sound is near the ear, and is not transmitted. : Pleuro-pericardial frictions or murmurs occur in cases of dry pleurisy involving the pleura of the pericardial sac and the adjacent lung. The sounds are not syn- chronous with the heart action, but occur with the respir- atory movements, and may disappear when the patient 821 Chest, Chest. holds his breath; they are usually heard loudest over the borders of the ventricles, when respiration is deep. The quality is rubbing, the intensity not marked, and it may be increased by pressure with the stethoscope. Endocardial Murmurs.—Endocardial murmurs may be due to gross changes in the valves or lining membrane of the heart, or to changes in the quality of the blood. In the first case they are called organic, and in the second functional, heemic, or inorganic murmurs respectively. Organic Endocardial Murmurs.—For the production of a murmur two factors are necessary: force and rapidity of the blood current, and narrowing or change in calibre of the passages through which the blood flows. The blood normally flows with force and rapidity through a passage with smooth walls, and of even or gradually diminishing calibre. When, as the result of disease, the cusps of the valves do not open properly to allow the blood to flow through, or when the curtains of the valves do not close perfectly and so allow the blood to flow back through the opening, a sudden diminution in the calibre of the passage occurs. Thus the two fac- tors for the production of a sound or murmur, the blood current passing with force and rapidity through a nar- row opening into a wider space, are present within the diseased heart. Should the velocity and force of the blood current be diminished, as the result of a weak heart, when a dimi- nution in the calibre exists, either there will be no murmur or a murmur of slight intensity will be heard. The valves on the left side of the heart are those most com- monly the seat of organic disease in adults. In early in- fant life and in intra-uterine life the valves of the right heart are usually those affected.. Inorganic, Functional, and Hemie Murmurs.—In addi- tion to the organic valvular lesions which render the valves unfit for the work they are destined to perform, the valves may be rendered incompetent on account of a dilated condition of the muscular walls of the heart and a consequent widening of the orifices, which the cusps of the valves are unable to fill in and close. This inabil- ity to close the dilated auriculo-ventricular orifice, for example, is due to the fact that the cusps of the mitral valve are too small, and also to the fact that the papillary muscles are displaced by the dilatation of the heart and so prevent the cusps from closing perfectly. An increased blood pressure in the aorta or pulmonary artery, or a loss of elasticity of the arterial coats, which causes a dilated condition of the vessels, may allow a regurgitation of blood at the aortic or pulmonary orifices. Murmurs due to these causes are spoken of as inorganic, or the result of relative insufficiency of the valves. Changes in the character of the blood may also produce sounds, to which the name “hemic” or “functional” murmurs is given. Organie Murmurs.—Sounds due to organic lesions are heard during either the systole or the diastole of the heart, and are therefore spoken of as systolic or diastolic murmurs. Those murmurs which occur during the dias- tole, but which end at the beginning of the systole, are called “ presystolic ” murmurs. Systolic murmurs, heard loudest in the aortic and pul- monary areas, are due to a stenosis or obstructed condi- tion of the aortic or pulmonary orifices. Systolic murmurs heard at the mitral or tricuspid areas are due to incom- petent mitral or tricuspid valves, which allow a regurgi- tation of blood through them. Diastolic murmurs in the aortic and pulmonary areas are produced by blood re- gurgitating through an incompetent aortic or pulmonary valve. Murmurs diastolic in time and heard in the mitral and tricuspid areas are caused by an obstructed or sten- otic mitral or tricuspid valve. The relative frequency of these murmurs is in the fol- lowing order (Broadbent): mitral regurgitation, mitral stenosis, aortic regurgitation, aortic stenosis, tricuspid regurgitation, tricuspid stenosis, pulmonary stenosis, pulmonary regurgitation. To take up the consideration of the murmurs in the order of their frequency: Mitral Systolic Murmur.—Mitral valve incompetent, 822 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. blood regurgitates into left auricle during systole of left ventricle. The most common cause of incompetence of the mitral valve is rheumatic endocarditis. Myocarditis, dilated left ventricle from any cause, or the infectious diseases may also produce this lesion. The murmur occurs with the systole of the heart; the quality is soft and blowing like a whispered “who,” pitch is low and intensity not loud; the duration is long. Area of maximum intensity at the apex; the murmur may be localized or may be transmitted toward the left into the axilla; it may also be heard in the left inter- scapular region along the internal border of the scapular. Mitral Presystolic Murmur.—The mitral valve is sten- osed or obstructed, and the blood is therefore hindered in its passage from the left auricle to the left ventricle dur- ing the auricular systole. The cause in nearly all cases is rheumatic endocarditis. The murmur occurs during the auricular systole ; toward the end of the long pause it becomes gradually louder and louder, and ends with the first sound of the heart. The quality is harsh, rough, and rolling, intensity marked, the area of maximum intensity usually small and just within the apex. This murmur is not, as a rule, trans- mitted. Aortic Diastolic Murmur.—Aortic valve incompetent, the blood therefore regurgitates into the left ventricle during the period of diastole. Rheumatic endocarditis is a common cause of this lesion; also atheromatous changes in the aorta and the cusps of the valve, as well as dilatation of the orifice. The murmur occurs with and replaces the second sound of the heart; it is soft and blowing in quality, often al- most musical; generally of rather bigh pitch, of variable intensity and short duration. The area of maximum intensity varies, it may be most marked in the aortic area; sometimes to the left of the sternum in the second, third, or fourth intercostal space; and at times at the tip of the sternum. It is transmitted across and down the sternum to the ensiform cartilage, and to the apex. Aortic Systolic Murmur.—Aortic valve stenosed or ob- structed, the blood hindered in its passage during the systole of the left ventricle from the ventricle into the aorta. This murmur may be due to true stenosis of the orifice resulting from rheumatic endocarditis or athe- romatous changes. It may be caused by atheroma of the first part of the aorta, by thickening and roughening of the aortic cusps, and sometimes as the result of aneu- rism and rupture of the valves. The murmur occurs with or replaces the first sound. Its quality is harsh and rough; it may, however, at times be soft, the intensity is usually marked and the dura- tion long. Heard with maximum intensity in the aortic area, and transmitted up the vessels of the neck. It may sometimes be heard all over the preecordium, and in the second, third, and fourth intercostal spaces on the left side near the vertebral column. HYPERTROPHY AND DILATATION OF THE HEART.— Hypertrophy of the heart is a thickening of the walls of the heart which may involve the walls of all the cavi- ties or be limited to those of one. Dilatation is’an in- crease in the capacity of the cavities of the heart; as in hypertrophy one or more of the cavities may be involved at the same time. 2 Hypertrophy and dilatation may occur together or sep- arately. With hypertrophy there is usually a certain amount of ‘dilatation. Hypertrophy results from the effort of the heart to do more work than normal. This demand for extra work may be due to excessive exercise, to functional causes, for example exophthalmic goitre, to mechanical defectsin the circulatory system, to valvu- lar disease, or to increased resistance in the peripheral or in the pulmonary circulation, depending on Bright’s disease, chronic bronchitis, or emphysema. The en- deavor of the heart to overcome any of the valvular lesions by hypertrophy is an effort of the organism to supply extra force where extra work is needed. If the hypertrophy is sufficient to overcome the symptoms arising from the valvular lesion, the lesion is said to be pies i Pts Pha # i. et ee Ct an nf 97° %, ® y i 2) Woe) 6 vi a, - aw EXPLANATION OF PLATE XXIII. (In all the figures the blue color indicates the superficial, and the red color the deep, cardiac dulness. The shaded wedges show the area over which the murmurs-are heard, and indicate by their thickness the intensity of the sound.) Fic. 1.—Mitral Insufficiency. Showing slight hypertrophy of left ventricle, and marked hyper- trophy of the right side of the heart. Accentuation of pulmonic second sound, indicated by the sign u-Z at the base. Murmur heard at apex with maximum intensity, transmitted to the left (>) and diminishing. Fic. 2.—Mitral Stenosis. Left ventricle of normal size. Hypertrophy of left auricle and of right. side of heart. Pulmonic secona sound accentuated. Maximum intensity within apex: mur- mur increasing to first sound (<). Not transmitted. Fic. 3.—Aortic Insufficiency. Left ventricle greatly hypertrophied. Right side of heart normal in size. Murmur heard over a considerable area, at times with maximum intensity at base in aortic area, at times at lower end of sternum. No accentuation of second sounds. Fic. 4.—Aortic Stenosis. Left ventricle somewhat hypertrophied. No changes on right side of heart. Murmur heard with maximum intensity in aortic area, transmitted up into cervical vessels. PEATE ALL REFERENCE HANDBOOK Aint = oO MEDICAL SCIENCES 7] Th Eee iy oe) Nea ae Ny SS yy GRAPHIC REPRESENTATION OF THE PHYSICAL SIGNS FOUND IN THE FOUR MOST COMMON VALVULAR LESIONS OF THE HEART Lehrbuch der klinisc From Sahli’s ‘ REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. compensated. This compensation results from the hyper- trophy of the walls of the cavity immediately behind the obstructed orifice. After the hypertrophy has existed for some time, the heart muscle fails to respond to the extra demand made upon it and becomes weakened; this is followed by a dilatation of the cavity and a failure of compensa- tion. Tuer PrystcAL Siens or HyPERTROPHY OF THE LEFT VENTRICLE (Plate XXII., Fig. 3).—Inspection.—Bulg- ing of preecordium, especially in children and adults with thin chest walls; apex displaced downward and to the left of the mid-clavicular line; @ heaving impulse over the precordium. Palpation.—A slow, heaving, and forcible apex beat. Pulse strong, and tension increased. Percussion.—Deep cardiac dulness extends more to the left and downward than normal; where the increase in deep cardiac dulness is very great there is probably dila- tation with the hypertrophy. * Auscultation.—First sound prolonged; occasionally there is amurmur to be heard, this occurs where the dila- tation of the ventricle and auriclo-ventricular orifice causes an incompetent mitral valve. The aortic second sound is usually markedly accentuated; it is clear and ringing, where the cusps of the valves are normal; muf- - fled and duller where atheroma has caused a thickening of the valves. There may also be a reduplicated second sound. In cases of emphysema the physical signs of hypertrophy are not marked; this is due to the volumi- nous lungs, which lie between the heart and the chest wall, and which interfere with the physical signs elicited by inspection, palpation, and percussion, especially in the latter method of examination, where apparently the area of superficial cardiac dulness is normal. In cases of emphysema where there is no hypertrophy of the heart the cardiac dulness is always diminished. Tue PuysicaL Signs oF HYPERTROPHY OF THE RIGHT VENTRICLE (Plate XXII., Fig. 2).—Jnspection.—Bulging of the lower part of the precordium, with pulsation in intercostal spaces to the right of the sternum and in the epigastrium. The apex beat is somewhat displaced to the left by hypertrophy of the right ventricle. Palpation.—Heaving pulsation and the dislocated apex beat are also detected by this means of examination. Percussion.—Dulness may extend for an inch or more to the right of the sternum from the enlargement of the right auricle. Auscultation.—Sounds are not much changed unless there is dilatation. There may be reduplication of the pulmonary second sound. DILATATION OF THE HEART gives these physical signs: Inspection discloses an apex beat, usually to the left of the normal site, and much less visible than in health; it is at times invisible. Thereisa diffused, undulatory, or wave- like character to the pulsation observed over the preecor- dium (Plate XXII.). Palpation shows a feeble impulse of irregular and flop- ping character. The pulse is irregular, small, of little tension, and rapid. Percussion dulness extends both to the right and left, depending of course on the portion of the heart most involved by the dilatation. Auscultation.—The heart sounds are feeble, and the rhythm is irregular. From the relative insufficiency of the valves murmurs may arise. When the dilatation is extreme and the force of the heart’s muscular contraction feeble, even though valvular lesions exist, no murmur may be heard. In such cases, after rest and the use of cardiac tonics, the contractions of the heart become more forcible and the murmurs again become audible. PurysicaL SigNs oF PERICARDITIS.— When pericarditis is unaccompanied by effusion of serum, the only physical sign is the friction murmur, the “see-saw ” sound, which is heard usually at the base of the heart. If the inflammation goes on, and an effusion of serum into the pericardial sac takes place, the following signs are noted: . Chest, Chest, Inspection.—Bulging of the preecordium; apex beat not visible or above the normal location. Palpation.—No apical impulse, or an impulse felt in the third and fourth left intercostal spaces. Fluctuation may be present, though this is a rare sign. Percussion.—W hen fluid is present in moderate amount _ the area of deep cardiac dulness is not increased, but the change from pulmonary resonance to flatness is sudden and marked. When the pericardial sac is distended with exudate, the dulness or flatness begins at the first or second costal cartilage, and extends downward to the sixth rib, and laterally beyond the normal limits of deep cardiac dulness. The outline of the flat area may be pyramidal and extend beyond the normal site of the apex beat. The sense of resistance on percussion is marked. Often the dulness of pericardial effusion is at first noted in the second left and fifth right intercostal spaces, Auscultation.—Friction sounds due to rubbing of the pericardial surfaces on one another may be heard, when the fluid is present in only small amount; when large amounts of fluid fill the pericardial sac, friction sounds are usually absent. The heart sounds are heard faintly and apparently at a distance; but when no endocardial murmurs exist they are normal in character. The difficulty of differentiating betweema dilated heart and a pericardial sac filled with fluid is often difficult. The fact that the apex impulse is absent or displaced up- ward, and not of the undulating character so typical of a dilated heart, in which also the apex beat is usually displaced downward and outward; the shape of the dull area, pyramida] in pericarditis, and square in a dilated heart; the muffled character of the sound in pericarditis, and the accentuated valvwtar sounds in dilatation; Bam- berger’s sign, dulness at the angle of scapula, and in- creased fremitus and bronchial breathing at this point when the patient sits upright, which signs disappear when the patient leans forward, in pericarditis and not in dilated heart, will aid in the differential diagnosis of these conditions. Mirra INsuFFICIENCY.—The mitral valve, incompe- tent, permits regurgitation of, blood into the left auricle during systole. This causes an increased amount of blood in the auricle and an increase in the blood pressure of the pulmonary circulation. The auricle becomes pri- marily dilated and hypertrophied. During each diastole, as a result.of the increased amount of blood in the left auricle and of the increased pressure under which this blood is, more blood enters the left ventricle than normal and with greater force; this causes an increase in the capacity of the left ventricle from the yielding of the walls, and then hypertrophy from the endeavor of the left ventricle to empty itself completely during systole. The increased pressure of the blood in the pulmonary circulation causes hypertrophy and dilatation of the right ventricle—the effort of nature to supply force for the lack of power in the left auricle. When dilatation of the right ventricle ensues, the tricuspid valve becomes incompetent and the blood during systole regurgitates into the right auricle, thence into the ascending and de- scending ven cave; pulsation of the veins of the neck and pulsating liver follow. As long as the hypertrophy of the ventricles is sufficient to overcome the valvular deficiency, just so long will no changes be noted in the character of the pulse, and no subjective symptoms will be observed (Plate XXIIL., Fig. 1). Inspection.—Bulging of precordium at times; apex beat displaced down and to the left; pulsation of the cer- vical veins and of the liver in extreme cases. Palpation.—Impulse displaced, but nothing character- istic; very rarely a thrill at apex. Pulse small and of low tension. If the compensation is failitig the pulsations of the liver may be felt. Percussion.—Area of cardiac dulness inereased to left, and also to the right of sternum, often an inch or more. Auscultation.—At the apex, in the mitral area, a soft systolic murmur is heard, transmitted to the left, to the axilla, and at times heard in back along the internal border 823 Chest, Chestnut, REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. of left scapula. Though the area of maximum intensity is at the apex, the murmur may be heard along the left edge of the sternum, and also at the base of the heart. The pulmonary second sound is accentuated. When dilatation of the right heart with the accom- panying insufliciency of the tricuspid valve has occurred, a tricuspid systolic murmur may be heard in the tricus- pid area; at this stage the pulmonic second sound is weakened. Mirrat SreNosts.—Mitral valve narrowed and the blood flow from left auricle to ventricle obstructed. The first result of the interference with the passage of blood through the mitral orifice is dilatation and hypertrophy of the left auricle, and an increase in the blood pressure in the pulmonary circulation; then hypertrophy and dila- tation of the right side of the heart follow, and engorge- ment of the systemic venous circulation. _ So little blood enters the left ventricle during the period of diastole that the cavity is not filled, therefore it neither dilates nor hypertrophies, and is not affected by the changes occurring in the other cavities of the heart. There being little blood in the ventricle, little is forced into the aorta with each systole, hence the pulse is small in size (Plate XXIII., Fig. 2). Inspection.—Bulging of preecordium, especially of ster- num and ribs to the right of sternum; apex beat not dis- placed, usually visible. Epigastric pulsation marked. Palpation.—The apical impulse is short and snapping, often accompanied by a presystolic thrill. Pulse is small ; may be regular if compensation is good, irregular when compensation is failing. Percussion.—Area of cardiac dulness is increased to right of sternum and upward. Auscultation.—Presystolic murmur heard at or just within the location of apex beat, over a limited area, rough and harsh in character, not transmitted, and end- ing suddenly with the first sound of the heart. The pul- monic second sound is usually accentuated. There is often a reduplication of the second sound at the base. At the apex the second sound may be inaudible. When compensation has failed this lesion may exist, and yet no murmur be heard. Aortic INSUFFICIENCY.—The aortic valve is incompe- tent, and allows blood to regurgitate into left ventricle during the period of diastole. The first result. of this lesion is, that during diastole the cavity of the left ven- tricle is overdistended with blood, flowing from the auricle through the mitral orifice and from the aorta through the incompetent aortic orifice. The ventricular walls yield to the pressure, and a primary dilatation results; this is followed by hypertrophy of the ventricle in the effort to force the increased amount of blood contained in the cav- ity into the aorta. It not infrequently happens that from the dilatation of the ventricle there isan incomplete closure of the mitral valve, the so-called relative mitral insufficiency, which acts in a beneficial way by allowing regurgitation and so relieving the pressure in the ventricle during systole. Aortic regurgitation produces a marked effect on the pulse. The more than normal quantity of blood forced into the aorta during each systole causes a sudden and marked filling of the arteries, a quick and full pulse; this as quickly disappears during diastole, when the arteries are emptying themselves in the normal manner, and also backward through the incompetent aortic valve. The pulse seems to collapse; it is the “water-hammer” or Corrigan’s pulse, and is character- istic of this lesion (Plate XXIII., Fig. 3). Inspection.—There may be bulging of the preecordium ; the apex beat is dislocated downward and to the left, and the impulse is usually marked and of the heaving char- acter of hypertrophy. There is marked visible pulsation in the cervical ves- sels and also in the temporal, brachial, radial, and other arteries. Capillary pulsation in the finger nails is visible at times. Palpation.—The abnormal location of apex beat and the forcible and heaving character of the impulse are easily made out. There may be a thrill in the aortic area 824 diastolic in time. The pulse, the characteristic Corrigan or “water-hammer,” is not marked when compensation fails, or when a marked stenosis of the aortic valve exists with the insufficiency. Percussion.—Cardiac dulness increased to the left from hypertrophy of the left ventricle. Auscultation.—Diastolic murmur heard over the aortic area, and transmitted across the sternum and downward along left edge to the tip of the ensiform cartilage. This is usually a soft and blowing murmur coming with or replacing the second sound of the heart. A systolic aortic murmur is not an uncommon accom- paniment of the diastolic murmur; and a mitral systolic murmur is also often heard, the result of the relative mitral insufficiency. Aortic STENOsIS.—The aortic orifice is narrowed, and an obstruction is thus offered to the passage of the blood from the left ventricle into the aorta. This causes an in- erease of blood pressure in the ventricle during systole; the ventricular walls at first give way to this increase of pressure and a primary dilatation results. This is rapidly compensated by hypertrophy of the left ventricular walls, which takes place as the result of the heart’s effort to empty the ventricle of the excess of blood through the narrowed orifice. The pulse is usually small, because of the small amount of blood forced into the aorta with each contraction of the heart, and regular. The tension is usually high (Plate XXIII., Fig. 4). Inspection.—Apex beat displaced downward and some- what to the left, visible and somewhat heaving. When compensation fails impulse is wave-like. There is no visible pulsation in any of the peripheral vessels. Palpation.—Apex beat palpable in sixth space and to left of the mammary line: impulse is slow, regular, and forcible. There is often a systolic thrill in the aortic area. The pulse is regular, small, and of high tension. Percussion.—Area of cardiac dulness increased to left from hypertrophy and dilatation of the left ventricle. Auscultation.—In the aortic area a loud systolic mur- mur is heard, often audible over the whole precordium and in the vessels of the neck. It may even be heard in the second, third, and fourth left intercostal spaces near the vertebral column. The murmur is systolic in time and usually very harsh in quality; it is transmitted up the vessels of the neck. The second sound is usually faint, it may be absent; or there may be a diastolic murmur replacing the second sound, due to an incompetent con- dition of the aortic valve. Murmurs occurring at the same time of the cardiac cycle arising from the same pathological conditions of the valves of the right heart may be heard, and the phys- ical signs resulting from these valvular lesions are much the same as those already enumerated. Lesions of the tricuspid and pulmonary valves are, however, compara- tively rare; and the murmurs heard indicating trouble at these orifices arise more commonly from the relative in- sufficiency of these valves, which is the result of organic lesions of the valves of the left side of the heart, than from structural lesions of these valves themselves. TricusPIp REGURGITATION.—Of the lesions at the tri- cuspid orifice regurgitation is the more common, and is usually the result of dilatation secondary to mitral dis- ease and consequent stasis of the pulmonary circulation. Inspection.—Pulsation in epigastrium, in intercostal spaces to right of sternum, and in the vessels of the neck. Palpation.—Pulsation in epigastrium and to the right of the sternum, and at times the pulsating of the liver may be felt. Percussion.—Heart dulness increased to the right edge of the sternum or beyond it, and upward, from the hy- pertrophy and dilatation of the right ventricle and auricle. Auscultation.—In the tricuspid area, at the end of the sternum and in the fourth and fifth left intercostal spaces near the sternum, a soft blowing systolic murmur is heard; it may be transmitted slightly to the right, but is not heard at the apex. The second sound in the pul- monary area is weak. Tricuspid STENOsIs.—This lesion is usually con- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. - Chest, Chestnut, genital and is accompanied by dilatation of the right auricle. Inspection.—Cyanosis is marked, and visible pulsation may be noted to the right of sternum. Palpation.—The pulsation and at times a presystolic thrill to the right of the sternum may be felt. Percussion.—Cardiac dulness, from the dilated right auricle, increased: to right of sternum. Auscultation.—Presystolic murmur, harsh in quality, of maximum intensity in tricuspid area, and not transmitted. PULMONARY REGURGITATION.—The physical signs are those due to the regurgitation of blood into the right ventricle causing it to dilate and hypertrophy. The murmur is like that of aortic insufficiency, diastolic in time and soft in quality; it is heard with maximum in- tensity in the second left intercostal space, and is trans- mitted down the sternum. The pulse alone makes it possible to differentiate the murmur from that due to aortic insufficiency. PutmMonarRyY STENOsIs.—This lesion, usually con- genital, causes hypertrophy of the right ventricle, with the usual train of physical signs. The murmur is systolic in time, harsh in quality, heard loudest in the second left intercostal space and at times all over the preecordium; a thrill may also be detected in the pulmonary area. The sound is not transmitted up the vessels of the neck, like the systolic murmur of aortic stenosis. FunctionaL Murmurs.—Functional murmurs are those which occur not as the result of any organic val- vular lesion, but from functional changes in the heart, vessels, or blood. These murmurs are often spoken of as inorganic, hemic, or anemic, from the fancied cause of their production. It is usual to find these murmurs in cases of anzemia, or in the debility following any exhaust- ing disease. The following characteristics of functional murmurs will aid in differentiating them from organic murmurs. They are always systolic in time, and are as a rule heard loudest in the pulmonary area, though they may be heard at the apex, and in the aortic and tricuspid areas. The murmur is soft and blowing, and usually louder when the patient is in the recumbent position. There is no transmission, and usually no hypertrophy or dilatation. The second sound in anemic murmurs is usually some- what accentuated. There may be vascular murmurs associated with the functional cardiac murmurs; the most common is that heard in cases of aneemia in the neck over the jugular veins: the so-called “ venous hum,” or “ bruit du diable.” This sound may be produced by pressure on the veins with the bell of the stethoscope in persons who are in perfect health. ANEURISM OF THE THORACIC AoRTA.—Aneurism of the arch of the aorta may be fusiform or sacculated, and is usually secondary to syphilis, alcohol, gout, or great muscular strain. The physical signs depend on the loca- tion of the aneurismal tumor, the presence of the tumor, and the pressure the tumor exerts on the surrounding structures. ’ The physical signs due to the tumor itself are pulsa- tion, usually expansile, thrill, dulness, and murmur. It is quite possible, however, for an aneurism to exist with- out giving any physical signs. Inspection.—If the aneurism is of the ascending arch, there is often bulging in the first and second right inter- costal spaces, and here also a pulsation may be visible. When the aneurism is located in the transverse arch of the aorta, the manubrium is pushed forward and the tumor shows itself in this location ; the pulsation is noticed here, and also in the suprasternal notch. Aneurism of the descending arch is usually accompanied by a tumor in the second left intercostal space in front, or in the third, fourth and fifth intercostal spaces of the left inter- scapular region. The use of the z-ray in examining patients in whom aneurism is suspected is of great assistance. By means of the fluoroscope the presence of a dark and pulsating shadow, larger than that seen in examining the normal heart, is made out, often when no other physical signs of aneurism can be detected. It is most important to make use of this means of examination in all cases of suspected aneurism. On inspection also the apex beat of the heart may be found dislocated downward and to the left. Palpation.—At the point of bulging, pulsation, usually expansile in character, may be noted, and a systolic thrill may sometimes be felt. When the aneurism is of the transverse or upper part of the descending aorta, tracheal tugging may be present. To obtain this sign, the head of the patient, who sits, should be supported against the body of the observer, who stands behind the patient; the observer then places the first or second finger of each hand on either side of the cricoid cartilage. The head should be slightly bent forward and the patient told to stop breathing. With each systole of the heart the fingers appreciate a distinct tug transmitted to them through the trachea and cricoid cartilage, which are dragged down by the expansion of the aneurism upon the left bronchus. 5; A difference in the character, time, and force of the pulse in the two wrists may be noted; the vessels re- ceiving their blood supply from the aneurismal sac hav- ing a weak and retarded pulse wave. Percussion.—There is dulness over the location of the tumor. When there is no visible tumor, dulness in the second right intercostal space or in the left interscapular region near the vertebral column is suggestive of aneu- rism. Auscultatory percussion is of much value in diagnosis of the presence of a tumor in the mediastinum. The heart dulness is usually not increased unless there is valvular disease, usually incompetence of the aortic orifice, associated with the aneurism. Auscultation.—There may be a systolic or a systolic and diastolic murmur heard over the tumor. Ina large number of cases, however, no murmur can be made out. The second aortic sound is accentuated; at times the closure of the valves is so forcible that the palpating hand can feel the shock. Pressure Symptoms.—An aneurism may exist and give no physical signs, yet characteristic pressure symptoms may be present. The symptoms caused by pressure often coexist with the physical signs due to the tumor, and depend largely on the location of the tumor and the structures upon which the pressure is exerted. Pain is usually a constant symptom, sharp and stabbing in character, and may occur in paroxysms. The pain may be due to the erosion of bone, sternum, or vertebre ; may be anginal in nature, or result from pressure on the nerves, and shoot down the arm to the fingers or along the intercostal spaces. Pressure on trachea and bronchi gives rise to cough, bronchorrheea, and hemorrhage, at times slight and ap- parently from the lungs, at times profuse and fatal from ulceration of the aneurismal sac and rupture into the trachea or bronchus, Pressure on vena cava, if on superior, causes cyanosis, enlargement of the veins, and cedema of the head, neck, and arms, usually the right; if on the inferior, there may be cedema of the thorax and feet. Pressure on the esophagus causes dysphagia, and the aneurism at times ruptures into the @sophagus. Pressure on the recurrent laryngeal nerves produces a dry me- tallic cough and aphonia. The paralysis of the ab- ductor muscles of the larynx is easily made out by laryn- goscopic examination. The left vocal cord is the one most frequently paralyzed. Pressure on the sympathetic nerves may produce contraction of one pupil, and flush- ing and sweating of one side of the face. Pressure on the brachial plexus, sternum, and vertebra produces pain. William EK. Draper. CHESTNUT.—Castanea. “The leaves of Castanea dentata (Marshall) Borckh. (fam. Fagacee), collected in September or October, while still green” (U. 8. P.). This 825 Chewstick, Chick’s Springs. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. is one of the largest and most valuable of our timber trees, growing rather rapidly, and producing an abundance of straight-grained, rather coarse, but very durable wood. The ripe fruit or nuts well known. The official descrip- tion is as follows: “From six to ten inches (15 to 25. cm.) long, about two inches (5 cm.) wide, petiolate, oblong- lanceolate, acuminate, mucronate, feather-veined, sinu- ate-serrate, smooth, odor slight, taste somewhat astrin- gent.” Doubtless other species of chestnut leaves have the same composition and might with equal propriety be used. Nothing peculiar has been found among the constituents of chestnut leaves; nine per cent. of tannin, resin, and a number of mineral compounds in the ash, are the principal things observed. Their use is entirely empirical. The leaves for a good many years have had a popular reputation for the relief , of whooping-cough, and within the last ten or fifteen - years have been considerably used in its treatment by physicians; their value for this purpose is, to say the least, uncertain. Sometimes there appears to be a marked decrease in the number and severity of the coughing spells; at others no effect is produced. They are not put to any other use. The fluid extract is offi- cial, the dose being 2 to 8 c.c. (fl. 3 ss.-ij.). W. P. Bolles. CHEWSTICK.—The stems of Gouwania Domingensis (fam. Rhamnacee). This is a beautiful woody climber, growing both wild and cultivated in the West Indies, and other parts of tropical America, whose stems are used there as tooth-brush and powder combined. These stems are very tough and fibrous, and when cut in short- ish pieces the ends are chewed until a rude, stiff brush is formed, with which the teeth are rubbed; a pleasant saponaceous froth of an aromatic bitter taste is formed in the operation, and the teeth are said to be whitened and the gums hardened by it. 8¥A VETAGELOL NOLMAl census taieme ates 25.8° | 45.4° | 72.8° | 48.8° AVerage Cally TANGLE. « vs \sisisiciny vie eciiolns s2 14.9 | 14.8 | 14.3. Mean Of WATMOSt Ty scccatinet oer cs teileteare 82.6 | 54 80.1 Mean Of Coldest.) csile Seeder aaalaie te tals 17.7 | 39.7 | 65.8 Tighest Or MAXIMUM Fj. cleais ciclsiniele careers 65 83 99 Lowest or miniMuM <....... 63 cccey.-s 0. —20 | 17 50 Humidity— Average OP relative jen ens co sscemern den 76% | 66.5% | 70.6% | 70.8% Precipitation— ae iia rainfall in inches ..........+..+. 2.04 | 3.65] 3.96 | 37.58 ind— : Prevailing direction... cnict cies eescleealcies ct S.W.| N. |S.W. | S.W: Average hourly velocity in miles ........ 9 D5 ihe vek 8.4 Weather— Average number of clear days.....2..... 7.8 8.1 | 12.9. | 108.5 Average number of fair days ...........+. 12.9 | 12.2 | 12.5 | 148.6 Average number of clear and fair days ..| 20.7 | 20.3 | 25.4 | 257.1 The authority above quoted does not think the Chicago climate contraindicates the establishment.of a sanatorium, in the vicinity, for the treatment of curable cases of con- sumption. “At any rate,” he says, “the climate in the lake region affords as good an opportunity as the climates of England and New England.” For a statistical ac- count of the Chicago climate one is referred to “The Climate of Chicago,” by Professor Hazen, 1893, of the Weather Bureau, published by the United States Gov- ernment. Edward O, Otis. CHICHANCANAB.—Yucatan, Mexico. The water of this lake is perfectly clear and very bitter in taste. It deposits crystals similar in appearance to those of mag- nesium sulphate. NV. J. Ponce de Léon. _ CHICHIMEQUILLAS.—Querétaro, Mexico. Nothing much is known of these waters. The laity recommends them in cases of rheumatism, leprosy, and disorders of menstruation. NV. J. Ponce de Léon. CHICHIPICO.—Puebla, Mexico. This is a lukewarm- sulphureted calcic water. Although there are no bath- ing facilities at this spring, many people take the baths, as they are highly recommended by local physicians, for the treatment of rheumatism and nervous disorders. NV. J.. Ponce de Léon. CHICKENPOX. — (Synonyms: Varicella, Crystalli, Swinepox; Fr., La Varicelle; Ger., Wasserpocken.) Chickenpox is an acute, specific, infectious fever, char- acterized by successive crops of vesicles distributed over the entire surface of the body, which disappear, in from four to seven days, by desiccation. It is the mildest and least important of the eruptive fevers. The belief, formerly generally entertained by the pro- fession, that varicella is not an independent affection but a modified variola, is now abandoned, save by a few clinicians who follow the teaching of Kaposi and the Vienna school. The proof of the non-identity of the two diseases is overwhelming. Varicella, like the other members of the exanthematic group, is due to a specific virus, or poison, the nature of which isunknown. It is pre-eminently a disease of early life. It affects babes at the breast, attains its maximum frequency about the fifth year, and is rarely met with after the tenth year of age. It rarely occurs a second time in the same individual. Adults enjoy special im- munity from the disease, even when unprotected by an attack in childhood. Sporadic cases of chickenpox are sometimes observed, but it usually prevails as an epidemic. It is highly con- tagious, and few children who are susceptible to its in- fluence escape when exposed. Many authors affirm that inoculation with the contents of the vesicles yields nega- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Chewstick, Chick’s Springs, — tive results, but Steiner and others have repeatedly re- produced the disease in this way. The period of incuba- tion in these experimental cases is about eight days, but when the disease is transmitted in the ordinary manner it is longer and more variable, running from ten to seven- teen days. : Prodromal. symptoms are not infrequently wholly absent, the appearance of the eruption giving the first indication that the child is ailing. When present, they rarely last longer than twenty-four hours, and are such as usher in mild febrile attacks, namely, anorexia, lassi- tude, general bodily discomfort, chilliness, and slight elevation of temperature. The initial fever is mild, seldom measuring more than 101° F., and the constitutional disturbances are corre- spondingly slight, but in exceptional cases they may be as severe as those which commonly attend mild attacks of the other eruptive diseases. The eruption follows promptly on the first increase in temperature, and in a few hours attains its full development. Small hypersemic patches resembling roseola spots first appear and are speedily followed by vesicles. When fully formed, the ' eruption consists of perfectly transparent vesicles, more or less abundantly scattered over the body, globular or ovoid in form, and varying in size from a pinhead to a split pea, or even larger. They are unicellular in struc- ture, collapse when pricked, and leave behind no swell- ing or elevation of the skin. A distinct areola may or may not be present. The wall of the vesicle, formed by the outer layer of the epidermis, is very thin and easily broken. When the eruption is abundant the body, as well de- scribed by Dr. Gregory, presents the appearance of hav- ing been exposed to a momentary shower of boiling water, each drop of which has produced a small blister. The eruption appears first upon the trunk, and spreads irregularly over the entire body. It is most abundant upon the back and breast, and least so upon the face, where it is usually limited to the forehead. The scalp nearly always exhibits a full crop of eruptions, which, protected by the hair, maintains its physical integrity longer than in any other location, and thus renders valu- able aid in diagnosis. The eruption is never confluent. The occurrence of two, three, or more successive crops of eruption, each running an independent course, consti- tutes a striking and unique feature of varicella. Be- tween the vesicles first formed new roseola spots appear, and soon ripen into fully developed vesicles. Thus, newly formed vesicles may be seen side by side with others in all stages of development, even to advanced desiccation. The irregularity in the course and develop- ment of the eruption is an important point in the diag- nosis of the disease. The mucous membranes are often implicated. The tongue, buccal.membrane, and the mucous surfaces of the genital organs, especially in girls, are favorite sites for the formation of vesicles. In these locations the vesicles soon lose their epithelial covering, and leave small, round, superficial ulcers resembling the ulcers of herpetic stomatitis. If unbroken by accident or by the scratching of the child to relieve the itching so generally present, the vesicles remain until the third day without change, when their contents become cloudy and desiccation begins. At this stage a few scattered pustules may be ob- served, but these are purely accidental and not essential features of the disease. The vesicles begin to dry up in the centre and form thin, brownish-yellow crusts, which soon become detached. Faint red spots remain, which pass away in a few days, and carry with them every trace of the eruption; but very exceptionally depressed, slightly pitted cicatrices permanently mark the seat of a few of the vesicles. Mr. Hutchinson has called attention to the gangrenous ulcers which sometimes, though rarely, complicate chickenpox in feeble, ill-nourished infants. In these cases a greater or less number of vesicles, instead of pur- suing the ordinary benign course, become gangrenous, increase in size, and form black scabs of. one-half to one inch in diameter, surrounded by dusky red areole. The ulcers heal slowly. In fact this.condition may result fatally in infants whose constitutions are depraved by inherited taints or bad surroundings. It is not peculiar to varicella and is described on other pages of the Hanp- BOOK under the name of Varicella Gangreenosa. The varieties of chickenpox described by authors under the names of Varicella lenticularis, Varicella conotdes, and Varicella globata, based on the various shapes assumed by the eruption, may be wholly ignored, since in every well-marked case vesicles answering all of these descriptions are abundantly found. In fact this variability in size and form of the typical varicellar erup- tion is a characteristic feature of the disease. The prog- nosis is always favorable. Erysipelas is the most serious, though a rare complica- tion. Holt has met with three fatal cases. Henoch and others have reported cases of nephritis occurring both as complications and as sequels. Vari- cella is not infrequently complicated by other infectious fevers. The combination of scarlatina and varicella has been often observed. Varicella derives its chief importance from the liability of inexperienced or careless diagnosticians to mistake it for smallpox, or vice versd. In variola, or well-marked varioloid, the physiognomy is so distinctive as almost to preclude the possibility of error. But in exceptional cases of varioloid the consti- tutional symptoms are so mild and the eruption so rudi- mentary and irregular that a careless examination will not suffice to distinguish them from the graver forms of varicella. For two years or more an unusually mild form of variola has prevailed extensively throughout the country, especially in the South and middle West. The mortality has been almost nil. In 2,819 cases recorded in Ohio up to January, 1900, the death rate was 1.4 percent. Dur- ing most Of the time varicella has been epidemic ina part of the same territory, which with the exceedingly mild type. of variola has given rise to much confusion and many mistakes in diagnosis. Time will always clear up the diagnosis, but in the meanwhile the reputation of the physician and the safety of the community may be seriously compromised. The absence of prodromal manifestations, the short initial fever, the rapidity and irregularity with which the eruption spreads over the body, the globular, non- umbilicated, transparent, unicellular vesicles, the absence of a distinct pustular stage, and the successive crops of eruption, which show roseola spots, vesicles, and crusts in close proximity, will rarely give room to hesitate in the presence of chickenpox. While any case of varicella may present an occasional vesicle slightly umbilicated or with purulent contents, due to accidental causes, the fact that this appearance is only.exhibited by a few scattered vesicles, and is not the predominating character of the eruption, will suffice to establish the diagnosis. It is well to bear in mind that a vesicular eruption which occurs ina child over ten or twelve years of age, and especially in an adult, is open to grave suspicion. The writer cannot, however, agree with those authors, by no means few in number, who maintain that varicella never occurs in the adult. He can recall three cases in adults, all females, which have come under his observation. Varicella is a self-limited disease and needs but little treatment. Light diet, cooling drinks, a gentle aperient, and con- finement within doors while the fever lasts, is all that will ordinarily be required. To prevent the infection of other children isolation should be maintained until the crusts have fallen. W. J. Conklin. CHICK’S SPRINGS.—Greenville County, South Caro- lina. Post-OFrFicE.—Greenville. Hotel and cottages. Access.—Via Atlanta and Charlotte Air-Line (Southern 827 Chicory. Childhood. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Railway system), to Taylor’s Station, 10 miles from Greenville. thence 1 mile to springs. Chick’s Springs are located in a broken, rugged coun- try, about 1,200 feet above the sea level. Paris Moun- tain, a spur of the Blue Ridge, is only three or four miles distant. The climate of this region is very salu- brious and well adapted for pulmonary cases during the winter months. The air is dry, and clear weather with invigorating breezes the rule. The resort has had a wide reputation in the South for many years, but owing to the destruction of the hotel by fire it has not been open to the public until two or three years since, when the present owner built a small hotel and several cottages. A large, new hotel is projected, which, with other im- provements, will bring the place up to its old standard of excellence. The springs are two in number, known as the “Iron” and the “Sulphur” Springs, and are about one hundred and fifty feet apart. The following analysis by Dr. Charles U. Shepherd, of Charleston, was sent to us by Mr. Julius C. Smith, of Greenville: ONE UNITED STATES GALLON CONTAINS: Solids. Calcitim sulphate try aerstetaverrcielaeeccteleeneetretelet- tats Magnesium sulphate Sodium sulphate............ Co uS Sodium. Silicate Secs iro) werews, «el siner einetee Mente nema rte rete Potassitim SUICate i. Ae vcieieess ros itelsioserthorelaiers sieved cuter ewieetele Silla cc cuase acinasoot eee ie ontaeicie pelea clea te er peatapeers 3 Tron OX9dO ohana we tice cteie stro neynismeionc ee omen aera’ Al Grains. Carbonic acid gas present in appreciable quantities. These waters have been found of great advantage in cases of atonic dyspepsia accompanied by hepatic con- gestion. They arealso useful auxiliaries in Bright’s dis- ease of the kidneys. James K. Crook. CHICORY.—Cichorium. The root of Cichorium In- tybus L. (fam. Cichoriacee). A perennial, milky-juiced, European herb, with dandelion-like leaves and _ tall, sparsely branching stems, bearing large, delicate, bright blue flowerheads. It is very abundantly naturalized in this country, along roadsides, and is also extensively cultivated both here and abroad. The root is fleshy and branched, very much like that of dandelion when dry, but rather larger, and deficient in regard to the bright yellow woody ring so distinctly seen in the cross section of dandelion. It is grayish brown externally, whitish within, generally odorless, and but slightly bitter. The cultivated root is larger and darker than the wild. It occurs in commerce mostly cut into halves and quarters of transverse sections, and is heavily wrinkled in drying. The leaves, which are somewhat employed as a salad, are irregularly pinnatified, with a large terminal and small lateral segments. They resemble lettuce in taste, but are more bitter. The roasted root is very extensively used as an adul- terant of, or addition to, or substitute for coffee, and this use is steadily increasing. In some European countries, especially England, it is generally assumed that the cus- tomer desires the addition of chicory unless he directs otherwise. To the natural taste, it imparts a bitter and nauseous flavor to the beverage, but this, by custom, be- comes tolerable or even agreeable. Chicory is scarcely entitled to rank as a medicine, al- though it is laxative and about similar to dandelion in its effects. The root contains énulin, like many others in the order, bitter extractive, and sugar. The flowers contain a peculiar glucoside. Henry H. Rusby. CHIGOE. — Synonyms. — Besides the classical terms Pulex penetrans, Dermatophilus, Rhynchoprion penetrans, and Sarcopsylla penetrans, this troublesome tropical para- site is known by the following names: aagrini, atten, bicho, bichos dos pes, chego, chegoe, chegre, chica, chico, chicque, chigga, chigger, chiggre, chigo, chigoe, chigua, chique, ckicke, earth-flea, jatecuba, jigger, mi- gor, nigua, pico, picque, pigne, pigue, pique, punque, 828 sand-flea, sandfloh, seccec, sico, sike, sikka, siko, tchike, tom, ton, tschicke, tschik, tschike, ti, tunga, tungay, xique. ErymMo.Locy.—Chigoe is supposed to be derived from the Spanish chiquito, small. For natural history, classification, anatomy, etc., see article /nsects. GEOGRAPHICAL DisTRIBUTION.—The chigoe is confined exclusively to the tropics, and is probably indigenous to. South America. It is most prevalent in the West Indies, and Central and tropical America, its bounds being about 30° of latitude North and South. Within these limits it is certainly very common indeed, and for its size is the most troublesome of all the tropical pests. Till about twenty-five years ago it had never been known out of the Western hemisphere, save for a stray case imported into Europe from South America or the West Indies (one such case is elaborately reported by Laboulbéne); but in 1872 or 1878 it was found in tropical Africa, and within the last decade it is said to have reached South China. Probably it will be found all over the tropics. It is most abundant in the dry sandy soil, and in the parts near the sea; also in pens, stables, and in the dust, ashes, etc., of neglected, unswept houses. Negroes are chiefly affected, and those who work or go about with bare feet, and are not accustomed to hygienic surroundings and conditions. Europeans and newcomers suffer the most, but probably because the older residents know what trouble these little pests can give, and have learnt from experience to appreciate the first signs of the presence of the parasite. Women and children with their thinner and more delicate skin suffer very much. Soldiers have been attacked by these tiny parasites and have been dis- comfited if not routed by them. “It is stated that as early as 1538 a division of Spanish troops was disabled from marching by swarms of the parasite settling in their feet. In recent times the French troops under Bazaine, in the Mexican expedition, had the same unfortunate experi- ence” (Hirsch). Short Description.—The chigoe is a parasite of the “flea” tribe; it is smaller than the flea, but has a larger head. It attacks birds, warm-blooded animals both wild and domestic, as well as the human subject. The male and immature female are both free parasites, obtaining their board and lodging wherever they can, but on im- pregnation the female seeksa host. It isthe impregnated female that causes all the trouble, and it is to her alone that we refer in the present article. With its head the chigoe bores into the skin, going obliquely through the epidermis; it then enters betweén the epidermis and dermis, and burrows down into the latter, but probably never goes deeper; from the capillaries of this region it obtains its food supply. Parts Affected.—All portions of the body are liable to attack, but the chigoe exhibits a decided preference for the feet. These are nearly always involved, especially under and around the nails, and in the digito-plantar fold. The insertion of the tendo Achillis is another favorite place. The dorsum of the foot is very seldom involved. Next to the feet, the scrotum, prepuce, corona glandis, axilla, arm, forearm, palm of hand, lower eyelid, cheek, neck, elbow, and knee are places of predilection; and as the feet and genitals are oftenest attacked, the question has been raised as to how far the chigoe is attracted by the odor of those parts, especially in the uncleanly. As a rule only one or a few chigoes are found, but Bonnett reports a case in which he found no fewer than three hundred in one person. It has also been stated that the chigoe likes to effect an entrance either near to another chigoe, or into the very spot which another chigoe has previously occupied; the neighborhood of an ulcer pro- duced by her comrades is also attractive to the chigoe. CLINICAL CoURSE AND SympToms.—Three stages have been described, but ordinarily only the first two are ob- served; and if proper care be bestowed the trouble is limited to the first stage. 1. Period of Invasion.—This lasts for from twenty-four to thirty-six hours, and is marked by itching and tick- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ling, due to the perforation of the skin. The sensation, which at first is not very definitely localized and some- times is a little way from the actual seat of the trouble, is rather pleasant than otherwise; and many people have been known to keep the insect for a day or two before extracting it. The pain.or discomfort is intermittent; but as the sac with the eggs increases in size it presses on the neighboring tissues and gives rise to a slight pain, which later becomes dull and throbbing and increases in intensity. At first there is nothing to be seen, but as the sac grows there can be observed a small spot, black or dark blue in color, and somewhat deeply set in the skin which at this stage is hardly raised. If the trouble be near a nail (as it is very apt to be) inflammation will soon follow unless the sac be carefully extracted. In delicate people even one chigoe will cause lameness and hinder walking. 2. Period of Inflammation.—If the insect be allowed to remain in the tissues, or the sac be ruptured and some of the eggs remain, inflammation ensues, the intensity of which depends on the thickness of the skin and the rich- ness of its vascular and nerve supply. If the skin is thick, there are pain, very little heat or redness, and little or no swelling; in other cases there are considerable pain, heat, and redness, and a serous fluid is present. If there are several parasites with well-developed sacs, the degree of inflammation is very great, and there is the possibility of further trouble. This second stage lasts for four or five days, sometimes longer; the inflammation only ceasing on the extraction of the chigoe. 3. Period of Ulceration.—lIf the part be still neglected and the inflammation remain unchecked, a large ulcera- tion occurs; the vessels may become obliterated, and gangrene is a possible result. Ulceration is very com- mon when several chigoesare present in close proximity : and the union of several small ulcers gives a very ugly sore. The ulcer is characterized by red, scalloped edges, grayish base, and thin fetid pus which may separ- ate the epidermis from the dermis. These ulcers are apt to spread along the surface, and in very severe cases the skin is destroyed, subjacent structures are denuded, tendons laid bare, phalanges may be necrosed, and toes drop off. This is exceedingly rare, and we believe that the severe symptoms attributed to this stage have been exaggerated. PROPHYLAXIS consists in personal cleanliness, particu- larly in constant bathing of the feet. Avoid sleeping on the ground, and do not go barefooted. Keep socks and bedroom slippers off the floor when not in use. See that rooms are swept and floors sprinkled. Some people use a -pungent essential oil to keep away the insect, the natives employing an infusion of tobacco leaves for this purpose. TREATMENT.—There is but one method that can be recommended, and that is careful extraction of the sac at the earliest possible moment. On the first itching sensa- tion a search should be instituted for the insect, which when found should be at once dislodged. This is best accomplished with a sharp needle, which should be steril- ized by passing through a flame, and then carefully in- serted in the opening made by the chigoe, and passed round the sac, separating it from the tissues, and when thus loosened it can be extruded. Great care must be taken to avoid breaking the sac and scattering the eggs. If unfortunately this should occur, wash out the débris with water (sterile if possible) or a mild solution of bichloride of mercury. If the skin is very thick an incision may be necessary. The negresses are skilful in “echi- quage” (as extraction of a chigoe is termed), but it is very necessary to see that they employ a surgically clean needle. Ifa dressing is considered necessary, a three or four per cent. solution of carbolic is as good as any. If the wound is large and intractable to ordinary treatment, you may have to curette and treat as any other fresh wound. Care must be taken to prevent the entrance of any pathogenic bacteria. Inflammation is treated in the usual way. If ulceration has occurred, chloroform lini- ment or mercurial ointment can be employed; and in the ‘may be necessary. Chicory. Childhood, very worst cases, and those badly neglected, amputation RR. J. E. Scott. REFERENCES. Bonnet: Arch. de méd. nay., 1867. Brassac: Arch. de méd. nay., 1865. Hirsch : Handbook of Geog. and Hist. Path. New Syd. Soc., vol. ii., 1885. Laboulbene : Dict. Encyclop. des Sciences Médicales, Paris, 1875, tom. Xvi. In the last two of these there is a very complete bibliography. CHILBLAIN. See Dermatitis calorica. CHILDHOOD.—In the arbitrary division of life em- ployed for purposes of description or discussion, child- hood includes the period from the end of the second year to puberty. The material for our consideration, there- fore, includes all the phenomena that belong to the human organism in its progress from the conditions pre- vailing at the end of the second year of life to those of maturity. Naturally at the outset of this period the organism, both in conformation and in function, corresponds closely to the infantile type, yet it has progressed sufficiently far to exhibit in some degree nearly all the powers that belong to the fully developed organism. No essentially new powers are developed until the concluding years of the period introduce the changes incident to puberty. At the end of the second year the body still maintains many of the infantile characteristics. The head is large in proportion to the size of the body, its circumference being about nineteen inches; the trunk is large in pro- portion to the extremities, the general outlines are full and round. The child at this age, however, has attained such a degree of muscular co-ordination that he is able to stand, walk, or run, and to use the hands freely.. The special senses are all awakened to a degree, and he has ac- quired a certain small store of experience, is constantly adding to that store, and in a feeble way reasoning upon the results of it. The same development from the condi- tion at birth, which is so especially notable in the case of the brain and nervous system, is also to be observed in the other organs of the body. The lachrymal glands are very active, the mouth has filled with teeth, the salivary glands have assumed their functions, the stomach and intestines are possessed of increased digestive power, and the eliminative functions of the kidneys are more in evi- dence. A more detailed consideration of some of the an- atomical and physiological peculiarities of childhood will be in order. The Skin.—The superficial area of the body in child- hood relatively to the size and weight of the body is much greater than in adult life. Changes in the condi- tion of the skin have, therefore, a relatively greater influ- ence in the earlier years. Children react to cold or hot applications to the surface of the body very quickly and markedly. Hydropathic treatment must therefore be carried out very carefully, and the length of exposure to either heat or cold regulated by the effect upon the gen- eral condition. Under proper regulation we can expect more marked and lasting effects from such measures in children in an inverse relation to their age. Thus simple sponging of the surface of the body with cold water or the application of a cold pack may be quite sufficient in a child to produce an effect which in an adult would re- quire a prolonged cold bath. The sensitiveness of the child to sudden changes of the temperature of the body should not be lost sight of in considering the questions of hygiene. The surface of the body should, as a rule, be protected, even in summer, The exposure of the neck and chest, arms and legs of a delicate child—often resorted to by mothers in the belief that it will “harden” the child—is much more likely to result in weakening it or even producing definite and severe illness. ; Except in the hottest part of summer flannel or wool should be worn next the skin, and whenever it is dis- pensed with, particular care should be exercised to pre- vent sudden chilling of the surface of the body. Proper 829 Childhood, Childhood. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. care of the surface of the body will protect a child from many of the attacks of inflammation of the respiratory or alimentary tract to which childhood is so susceptible. On the other hand, daily bathing should be as sys- tematically carried out in childhood as in infant or adult life. No specific rule can be given for the temperature or duration of the daily bath. These must be regulated according to age and constitutional vigor. A bath that leaves a child blue, cold, and shivering for some time after it must be harmful, but such results are unneces- sary. Either-by lessening the duration of the bath or by raising the temperature of the water, they may not only be avoided, but in their stead we can secure a healthy reaction which will leave the skin warm and glowing and the child stimulated and strengthened. No other one measure is so potent in increasing the vitality of weakly children and enabling them to avoid the constant recur- rence of colds as systematic bathing with water at the lowest temperature compatible with a proper reaction. Asa rule, the gradual reduction of the temperature of the bath is not only feasible, but advisable. The rate of reduction must be regulated by the effects produced. Not only is the skin area relatively greater in child- hood, but the skin itself is more delicate and more readily affected by any application. The use of external reme- dies, either in the form of lotions, ointments, dressings, or local applications, must be carefully watched and lim- ited to small areas. Local irritants or caustics are to be employed with care. Blisters, burns, and severe ulcera- tions are readily produced by incautious applications to the skin; even grave constitutional effects may be pro- duced by the external use of such readily absorbable sub- stances as carbolic acid and its allies. The skin in childhood readily reflects disturbances of other parts of the body, especially the gastro-intestinal tract. Eruption’ dependent upon disturbances of the stomach or bowels are frequently seen, and the dietetic treatment of skin diseases is seemingly much more potent in childhood than in adult years. The Bones.—At the beginning of childhood the bones are still very cartilaginous and soft. Ossification pro- gresses very slowly till puberty is reached. The fonta- nels are closed, but the bones of the skull are still rela- tively thin and soft, and the sutures remain open for many years. The spine of a child is remarkably soft and flexible, because of the limited ossification of the verte- bre. At the end of the second year it still presents the nearly perpendicular column characteristic of infancy. During childhood the S-like antero-posterior curvature characteristic of adult life is developed. Owing to the softness of the vertebree and the laxity of the ligaments, the conformation of the spine during childhood is readily influenced by the attitudes of the body, and much more attention than is usually given should be paid to the pos- tures and carriage of the child. The thorax of the child gradually changes its form from the change in the curvature of the spine and attendant changes in the direction of the ribs. The ribs, as age increases, are directed more obliquely downward. The thorax becomes relatively broader above than be- low, a reversal of the conditions found in infancy. The pelvis in childhood gradually enlarges so as to be more capacious,-and receives more of the abdominal vis- cera, thus diminishing the prominence of the abdomen so notable in early life. There is practically no difference in the pelves of the two sexes until the changes of puberty introduce the special characters of the sexes. The bones of the extremities in childhood show the di- vision into diaphyses and epiphyses. There is active growth at the junction of the shaft and epiphysis; the bones are still soft and easily affected by pressure. In consequence of these conditions deformities are easily produced, and are also, as a rule, readily amenable to proper mechanical treatment. The Teeth.—At the close of the second year, or within the following sixth months, the eruption of temporary teeth, twenty in number, is completed. At this time the child has not only the temporary teeth, but also the cal- 830 . cified crowns of all the permanent teeth except the second and third molars. The crowns of the second molars begin to be calcified during the fourth or the fifth year, but the third molars, or wisdom teeth, are not calcified till pu- berty. At the end of the fifth, or the beginning of the sixth year, therefore, the jaws contain not only the tem- porary teeth, but all the permanent excepting the wis- dom teeth. At this period there occurs a marked devel- opment of the jaws in the horizontal plane, in order to accommodate the permanent molars, which make their appearance posteriorly to the temporary molars. The permanent teeth are cut in the following erder: Year. MOISE OU Shia dahtacscstlalarielve sone Sixth. Incisor, COmUraly ncurses creistentersters Seventh Incisor, lateralis vss esis. eres Eighth Bicuspid, anterior............+. Ninth. Bicuspid, posterior ............. Tenth. : CANINES Fic cescie tsclelsinh srewisiacivet aie Eleventh to twelfth. Molars, SCCON . ‘ « i . ‘ , a Er - ” ’ * “ . a é ma 2 wet " ‘ aa ’ im ‘ : y= a 7 . ‘ - ro ae 5 * , 5 : ; ‘ k Os = A ‘ j . Pes Ms A _ . > E _- . - | . eh ae he ; : ha ri ‘ 4 E = so - ae . , aL ‘ : hia < . we E ¥ i : a - i + + . E o 34 . Oe | >. - : a a he oe —~ * P . 4 = fe i ey ~ ‘ . , x r . F : 4 re ’ i) ‘ ’ . * . . 4 * , 4 — ' . cig " . , ' ‘ cn ‘ - - * - ~ ‘ w } ’ . ~ . ’ a - % At = . 2 & j ” bad + ’ ‘® & eel x * a ‘ 2 . ~ 8 ‘ ‘