ou S ir Pane ais PO SeR rie soem z Be oe ee Seige Sapien Sean Ea Ditien ante naes Soe en sat sah ea 5 Le Stan Lea ap RUS ie annea se ae see By RE eon eee es i mecwers Serene Dene ae SDE iets OU i aiay Ue aso FORIp Rene vice! : heats sea epieti Peps fe tee Seria ees eee ees ares Sg Ss ores Taos Bae ae eee iy ties cone ee sere Bye Te Hise paca ea eat ean eee a pee Lee! Bai tae ea perma ais es ae AR ate Careaea aE fi Were pas Sh esasiesrt san CaM ALR a Pepoed tie tie tems Seon Spier ea Seach ioe henennrry 5 ee eee et cy a pase eat aed Soa ae caaca o Baie merece an pear eae seb shine teen ay ad ras A Sa ten te srs trees CORNELL LAB of ORNITHOLOGY LIBRARY at Sapsucker Woods es Illustration of Bank Swallow by Louis Agassiz Fuertes CORNELL UNIVERSITY The WILLIAM D. SARGENT Collection © cA Gift to the Laboratory of Ornithology + THE MYOLOGY OF THE RAVEN. THE MYOLOGY OF THE RAVEN (Corvus corax sinuatus),. A GUIDE TO THE STUDY OF THE MUSCULAR SYSTEM IN BIRDS. BY R. W. SHUFELDT. London: MACMILLAN AND CO. AND NEW YORK. 1890. The Right of Translation and Reproduction is Reserved. ORNITe SRRGENT ae 677 SS Mh 35705 RicHaRD Cray anp Sons, LimiTEp, LONDON AND BUNGAY. PREFACE. THERE has not yet been published, so far as the writer is aware, any work devoted to a complete account of the muscles of any single species of the Class Aves,—a work fully and practically illustrated, and one that would prove itself to be of service to those either engaged in the general study of the morphology of vertebrates, or to those special students who may be investigating the myology of birds. At the present time,—when the study of the structure of animals is becoming far more general, as one of the most efficient aids to observation and mental training, than it was so considered a number of years ago,—books of the class which your author has here endeavoured to produce come to be very useful. Birds stand among the most casily procurable subjects for the use of the demonstrator at the laboratory, or for the student to employ in his own researches at home as illustrative of certain parts of his course in biology. And it was to fill this so important a gap, as the lack of a suitable volume devoted to the muscular system of birds, that the writer undertook an exhaustive study of the muscles of the Raven (Corvus corax vi PREFACE. sinuatus) ; and the work here placed before the reader, with its eighty and odd figures, is the outcome of those investigations. With regard to my nomenclature of the muscles I have here described and figured, I have been guided by such brief chapters as are devoted to this subject and which appear in the published scientific memoirs of such excellent authorities as Owen, Carus, A. Milne- Edwards, Huxley, Garrod, Forbes, Selenka, Coues, Fiir- bringer, and Gadow ; but when I have been in doubt, and these authorities failed to assist me, I have en- deavoured to bestow upon the muscle a suitable name. The student must bear in mind, too, that many other birds possess muscles which are not to be found in the Raven ; in some special cases I have alluded to these. On the other hand, the muscles, even in the represen- tatives of the same species, may vary in certain in- dividuals to some extent. This fact has long been appreciated by anthropotomists. Gadow’s work upon the muscles of birds, which appeared in Bronn’s Thier-Reichs, is an admirable con- tribution to the general subject ; but it is by no means a work that meets the general want, and possesses the disadvantages of being but meagrely illustrated, and of having appeared in German, in a work of limited cir- culation. Notwithstanding this, I am quite sure my reader will feel grateful for my having incorporated Gadow’s synonymy in footnotes in the present volume, as they cannot fail to be anything but the most useful adjunct to a guide to avian myology. In arranging and grouping the elements of this PREFACE. vii system, it is to be hoped that the writer’s plan will be found to be a convenient and helpful one: it was his chief aim throughout, next to accuracy and clearness of description, to make it so. In choosing the Raven for our subject, it was done in view of the fact that it is a large representative of a very numerous and cosmopolitan family of birds, the Corvide ; so that, in almost any part of the world, a variety of birds become available whose muscular sys- tems can be studied by the aid of the present volume. It is hardly necessary to add that Crows of all descrip- tions, Jays, Orioles, and a host of others, all fall within this category. It has its advantage, too, for the teacher and the student at the biological laboratory; for the former can use as his subject the larger and more advan- tageous specimens, as the Ravens or Crows, while the latter can confirm the instructions of the former, at home, upon any of the smaller varieties of the Corvida, such as the Jays or Rooks. As his investigations in the myology of vertebrates progress, three lines for improvement, in so far as our knowledge of the muscular system of birds is concerned, will force themselves upon the student. In the first place, we still remain very ignorant of the details of this system in a great many important types of birds; secondly, an ever-pressing demand is evident, to fix the homologies of muscles in the Vertebrata, and conse- quently to bring so far-reaching a knowledge of this department of research to our assistance as to be enabled to give the same name to the same muscles, accurately, throughout the vertebrate series; finally, a simple, viii PREFACE, scientific, and euphonious nomenclature is very much to be desired. As an index of our present status with respect to our knowledge of the muscles of birds, it is hoped that the volume here offered will faithfully repre- sent it, but its writer trusts that in future works he may lend his assistance to the improvement of all the lines above indicated. ‘To this end, he will be thankful for any suggestions that may be uscful should the present volume go to another edition, and good criticism of the same will be welcomed from any quarter. Already, the question of neuro-myology, or the nomen- clature of muscles based upon their nerve-supply, has made considerable progress in modifying our views in that direction, and although I am convinced that it by no means always furnishes an invariable guide to follow, still its great usefulness is not to be ignored. With no little interest I have read the ‘‘ Neuro-myology ” of Coues and Shute (New York Medical Record, July, 1887), and am compelled to admire the masterly manner in which they have instilled new life into an old theme. Unfortunately, the same muscle as represented in different types of the vertebrate series, is not always served by the same nerve, and this would stand in the way of a general grouping and a universal neuro- myological nomenclature upon any such a basis. To those of my readers who are familiar with German, the best works I can recommend to be consulted in the present connection are the very excellent treatises of Sclenka and Gadow in Bronn’s Klassen des T; hier-Reichs; and that superb monument to avian morphology, the Untersuchungen zur Morphologie und Systematik der PREFACE. ix Vogel of Max Firbringer. To Professor Gadow I am indebted for a great many titles of works which I have incorporated in the bibliography which is found at the end of this volume; still, I have personally examined the majority of books there enumerated. English and American literature, as I have already stated, furnishes us with no good handbook to the subject. Frequently, an author, as he closes his prefatory remarks, finds that he has a host of helpful friends to whom his thanks are due for assistance rendered: it proves to be the exception in the present instance, for all of the material used was collected by myself; all the dissections were made by myself; all the descriptions are in my own handwriting; and the drawings were all drawn directly from the dissections by myself. Still it gives me pleasure to remember here my friend Dr. J. L. Wortman, the biologist of the United States Army Medical Museum, who, several years after this volume was written, carefully passed over with me the mus- culature of the shoulder-joint in birds, and verified my dissections :upon the Raven, comparing them with similar studies he was at the time engaged upon in the Raptores. Further it gives me pleasuré to express my thanks to Dr. G. Brown Goode, of the United States National Museum, for having upon a number of occasions furnished me with the means of preserving my somewhat extensive material, and that, too, when my labours upon the present volume were being prosecuted in New Mexico, between two and three thousand miles from civilization, the libraries, and the x PREFACE. museums; and that at atime when the operations of a short-sighted and destructive policy which influences our Government in its attitude toward scientific inves- tigators came quite near placing the researches herein tendered to my readers and collaborators in anatomy, beyond the pale of publication. Ke Takoma, D.C. August 20, 1889. CONTENTS. PAGE PREEACE 3 G4 408 a ¢ BR we eee eG eR ER Se OF LIST OF ILLUSTRATIONS... 1. 1. ee ee ee ee XT INTRODUCTION. . . . 1... 2 eee Sa a ig 1 THE DERMAL MUSCLES .......... 2... 8 4.4 4 3 THE MUSCLES OF THE HEAD. ..........2..,.. 415 THE MUSCLES OF THE TONGUE .......4... > ae 23 THE MUSCLES OF THE AIR PASSAGES ..... a wee 43 THE MUSCLES OF THE EYE AND EAR ........... 458 THE MUSCULATURE OF THE FAR ........, bee. 562) THE MUSCLES OF THE UPPER EXTREMITY .......... 66 THE MUSCLES OF THE LOWER EXTREMITY . og ere @. TBS THE MUSCULATURE OF THE TRUNK ........... . 258 BIBLIOGRAPHY: «4 § & % @ se ea Ye ww ww xa a 3819 INDEX) if SoS a ON A ae ea Re a SD we wae) B89 LIST OF ILLUSTRATIONS. [Nor :—All the figures illustrating this work were drawn by the FIG. . Side view of the skull of the Raven, showing points of -1 author, and with but few exceptions, where they have been copied from the drawings of other anatomists, were made directly from the recent dissections, and in the vast majority of cases the size of life.] PAGE origin and insertion of muscles . ......... 7 . Superior aspect of skull of the Raven, showing points of origin and insertion of muscles . ......... (i . Showing points of attachment of muscles on the basal aspect of the skullinthe Raven ......... «17 . The posterior aspect of the skull in a Raven, showing origin and insertion of the muscles ........ 19 Side view of the mandible in Corvus coraax sinuatus, show- ing the areas of muscular origin and insertion... . 21 Corvus corax sinuatus, the mandible from beneath, showing points of attachment of muscles ......... 23 . Corvus corax sinuatus, dissection of muscles of the head, seen uponright lateralview. ........-.+.. 28 xiv FIG, 10. 11. 12. 13. 14. 15. 16, 17. 18, 19, 20. 21. LIST OF ILLUSTRATIONS. Corvus corax sinuatus, oblique view of bones of shoulder- girdle, showing areas of attachment for muscles . Corvus corax sinuatus, the hyoid arches from beneath, showing points of attachment of muscles . Corvus corax sinuatus, superior view of bones of the upper larynx, showing points of attachment of muscles . Corvus corax sinuatus, the muscles of the head, seen from beneath . The tongue and salivary glands of a Ras ieil is Owen) - io 2B BS oe eR 8 Front view of the lower larynx of a Raven, showing muscles (afterOwen). . 2... 2... 7 ee ew Side view of the lower larynx of a Raven, showing muscles (after Owen) ..... ee ee ee ee Lower larynx of a Parrot (after Owen) . Muscles of organ of hearing in an Owl (after Owen) . Corvus coraz sinwatus, its hyoid arches from beneath, showing points of muscular attachment .' Corvus corax sinuatus, its hyoid arches from above, show- ing points of muscular attachment . Corvus corax sinuatus, the musculature of its Windpipe. . Corvus corax sinuatus, the head from above, with roof of orbit removed Mesial aspect of an eye of a Goose (after Owen) . Corvus corax sinuatus, side view of skull to show origin of eye-muscles in the orbit PAGE 31 31 31 32 44 44 44 44 44 46 46 50 54 55 FIG, 24, 25. 26. 27. 28. 29. 30. 3. 32. 33. 34, 35, LIST OF ILLUSTRATIONS. . Corvus corax sinuatus, muscles at the back of the eye, dis- sected . Corvus corax sinuatus, right lateral view of the skeleton of the trunk, showing areas of muscular attachment Corvus corax sinuatus, the sternum from in front, showing areas of muscular attachment . Corvus corax sinuatus, superficial muscles, anterior aspect, of the upper extremity, as far as the elbow Corvus corax sinuatus, anconal aspect of right humerus, showing where the muscles arise and are inserted . Corvus corax sinuatus, proximal view of head of humerus, to show muscular attachments . Corvus corax sinuatus, palmar aspect of humerus, to show points of muscular attachment Corvus corax sinuatus, radial aspect of humerus, to show points of muscular attachment Corvus corax sinuatus, ulnar aspect of humerus, to show areas of attachment of muscles Corvus corax sinuatus, anterior aspect of some of the muscles of the upper extremity Corvus corax sinuatus, superficial muscles of the upper ex- tremity in the region of shoulder and dorsum Corvus corax sinuatus, oblique left lateral view of the second layer of muscles of the upper extremity, being those of the dorsum and arm Corvus corax sinuatus, left oblique view of the body, dis- sected to show the deep muscles about the shoulder . XV PAGE 60 68 71 77 83 83 83 83 83 89 97 103 107 xvi FIG. 35 bis. Axillary muscles of the side of Gallinula chloropus LIST OF ILLUSTRATIONS. (after Garrod) 35 ter. Outer aspect of the axillary muscles of the right arm in a specimen of the Mourning Dove (Zenaidura macroura) . . 35 quat. The plucked body of a bird, drawn to show where to make the incision to expose the patagial muscles . 35 quin. Muscles of the patagium in Icterus vulgaris (after Garrod)... 35 sex. Muscles of the patagium in Progne subis . 36. 37. 38. 39. 40. 41, 43, Corvus corax sinuatus, bones of forearm and hand, showing muscular attachments Corvus corax sinuatus, radial aspect of left ulna and radius, showing where muscles are attached Corvus corax sinuatus, outer aspect of left forearm and pinion, showing the position, origin, and insertion of the superficial layer of muscles Corvus corax sinuatus, inner aspect of left forearm and pinion, showing the position, origin, and insertion of the superficial layer of muscles Corvus corax sinuatus, outer aspect of forearm and hand, showing relative position, origin, and insertion of the deep layer of muscles Corvus corax sinuatus, inner aspect of forearm and hand, with the superficial layer of muscles dissected away, showing the origins and insertions of the deep layer . Corvus corax sinuatus, anterior aspect of the bones of the left. hand, showing origin and insertions of muscles . Corvus corax sinuatus, ulnar aspect of the bones of the left hand, showing origin and insertions of muscles . PAGE 110 110 112 113 114 121 126 131 140 143 145 152 152 LIST OF ILLUSTRATIONS. FIG. 44. Corvus corax sinwatus, posterior aspect of the bones of the left hand, showing where muscles are attached . 45, Corvus corax sinuatus, anterior aspect of left femur, show- ing where the muscles are attached to it 46. Corvus corax sinuatus, posterior view of left femur, show- ing points where muscles arise 47. Corvus corax sinuatus, inner aspect of left femur, showing areas where muscles are attached 48. Corythaix erythrolopha, dissection of its thigh muscles (after W. A. Forbes) . . 49. Corvus corax sinuatus, skeleton of left posterior extremity, showing muscular areas of attachment 50. Corvus corax sinuatus, head of its tibia (enlarged), to show points of origin of muscles . 51. Corvus corax sinuatus, left tibia and fibula, showing mus- cular attachments . 52. Corvus corax sinuatus, anterior view of left leg bones, showing where their muscles are attached . 53. Corvus corax sinuatus, left leg bones seen from behind, showing muscular attachments 53 bis. Right three-quartering view of the pelvis of a speci- men of the Piiion Jay (Cyanocephalus cyanocephalus), showing the origin of the obturator internus muscle of the right side, 0.1. Enlarged . 54. Corvus corax sinuwatus, visceral aspect of pelvis and tail vertebra, showing the obturator muscle and its origin 55. Corvus corax sinuatus, anterior view of tarso-metatarsus, with muscular areas shown upon it . 56. Corvus corax sinuatus, posterior view of tarso-metatarsus, showing areas of muscular attachment 6 XVil PAGE 167 167 167 173 178 187 187 187 192 xviii LIST OF ILLUSTRATIONS. FIG, 57. Corvus corax sinuatus, summit of tarso-metatarsus, seen from above . 58. Corvus corax sinuatus, basal joint of hallux, seen upon superior view . 59. Corvus corax sinuatus, basal joint of hallux, seen from beneath . 60. Corvus corax sinuatus, skeleton of left foot, seen from be- hind, showing the areas and points of attachment of muscles 61. Corvus corax sinuatus, outer aspect of the skeleton of left pelvic limb, showing superficial muscles of thigh and leg 62. Corvus corax sinuatus, skeleton of left foot, designed to show where the tendons pass 62 bis. Outer aspect of the — pelvic limb of Geococeyx califormianus . ee at. Since 63. Corvus corax sinuatus, outer aspect of left pelvic limb, showing second layer of muscles. , 63 bis. Pelvic limb, right side, of Geococcyx californianus ; the superficial layer of muscles removed 64, Corvus corax sinuatus, outer aspect of left pelvic limb, showing third layer of muscles of thigh and leg . 64 bis. Pelvic limb, right side, of Geococcyx californianus, showing muscles of the third layer, and the ambiens 65. Corvus corax sinuatus, outer aspect of left pelvic limb, showing the fourth or wan layer of muscles of thigh and leg oe BSR ey eae a 65 bis. Pelvic limb, right side, Geococeyx californianus, show- ing the deepest layer of muscles . PAGE 201 206 207 210 2138 Lo rar oo 224 231 FIG. LIST OF ILLUSTRATIONS. 65 ter, Right foot of Megalema asiatica, showing an arrange- ment of the plantar tendons 65 quat. Left foot of Gallus bankiva . 65 quin. Right foot of Apteryx . 66. 67. 68. 69. 70. 71. 73. 74. 75. 76. Corvus corax sinuatus, dorsal aspect of the skeleton of the trunk, designed to show the areas where muscles are attached to it . Corvus corax sinuatus, cervical vertebre, showing where muscles are attached to them Corvus corax sinuatus, cervical vertebra, showing where muscles are attached upon their lower aspects . Corvus corax sinuatus, side view of cervical vertebra, showing points of origin and insertion of muscles Corvus curax sinuatus, dissection of muscles of head and neck, seen on lateral aspect . Corvus corax sinuatus, six leading cervical vertebrae (en- larged), side view, showing deep-seated muscles . Corvus corax sinuatus, dorsal view of sixth, seventh, and eighth cervical vertebre, showing the deep muscles that are attached to them Corvus corax sinuatus, side view of trunk, showing dissec- tion of superficial muscles attached to it Corvus corax sinuatus, side’ view of the trunk, showing the deep layer of muscles Corvus corax sinuatus, muscles of the diaphragm . Corvus corax sinuatus, visceral aspect of pelvis and skeleton of the tail, showing the muscles attached to them xix PAGE 239 239 239 260 269 269 274 280 293 300 313 317 THE MYOLOGY OF THE RAVEN (Corvus corax sinuatus). INTRODUCTION. In all highly specialized birds, and more particularly in those possessing great power of flight, such as the Oscines, the Raptores, and many of the Anseres, the various muscles are chiefly noted for their density, their dark carmine colour, and the distinctness between the fleshy portion and the tendinous. These char- acteristics are best seen in those groups of muscles which are brought into play during flight. As a rule, through- out the system, the tendons are very firm, dense, and of a bright pearly white colour; and these, in the limbs especially, show a marked tendency to ossify. Having obtained a fine adult Raven (or Crow), showing but few or slight injuries incident to its cap- ture, and having completely and carefully plucked the specimen, it is to be immersed in 80 per cent. alcohol for at least forty-eight hours. The student then must supply himself with a large delf platter, for a dissecting tray ; a grooved director, a set of hooks and chain, a pair of wide-aperture spring forceps, and finally, three or four suitable scalpels of various sizes. Everything being in readiness, the first object of B 2 THE MYOLOGY OF THE RAVEN. our dissection will be to demonstrate and expose the cutaneous system of muscles, or the dermal muscles. The dermal muscles are principally of two kinds: viz. the dermo-osseous, and the true dermals. The first- named have their origin on some part of the skeleton, and their insertion in the integuments ; while the second kind both arise and are inserted in the skin or some of its appendages. We never find all the known dermal muscles in any one form ; they vary with certain characteristics of the bird. The Peacock has a special dermal muscle to act upon the gorgeous fan which it spreads, and is com- posed of the feathers of the lower part of the back. Other birds having large crests, and peculiar skin developments about the head, which require special movements, possess the appropriate dermal muscles to operate upon them. Again, all birds possess an enormous system of minute muscles divided up into an infinite number of fasciculi, to harmoniously act upon the feather-quills, and collectively agitate the plumage. These are quite conspicuous in the Raven, but will not be especially dwelt upon. With an ordinary lens their action may be studied with comparative ease in one of the large quill-butts of the pinion, or tail. In the Raven the apteria are entirely devoid of muscles, and even the other dermal muscles often appear to turn out of their usual direction to avoid these tracts. The muscles may be arranged, according to the usual divisions of the body, into those of the cutaneous system; those of the head and neck; those of the trunk; those of the upper extremity ; those of the lower extremity ; and those devoted to the organs of special sense. I. THE DERMAL MUSCLES. 1. TRUE DERMAL MUSCLES. 2. DERMO-OSSEOUS MUSCLES. 1. The dermo-frontalis. 2. The circumconcha. 4. The dermo-dorsalis. 3. The dermo-temporalis. 6. The dermo-tensor patagii. 5. The platysma myoides. 12. The dermo-humeralis. 7. The dermo-cleido dorsalis. 13. The dermo-pectoralis. 8. The cleido-trachealis. 9. The dermo-spinalis. 10. The dermo-iliacus. 11. The dermo-ulnaris. 1.° The dermo-frontalis.—Carry an incision through the skin down to the bone, on the superior aspect of the head, parallel and close to the base of the upper mandi- ble, extending completely across. Next, from the outer 1 Selenka, in his classical work devoted to the anatomy of birds (Bronn’s Klassen und Ordnungen des Thier-Reichs, Sechster Band. IV. Abth., Vogel: Aves. 3u. 4 Lieferung et seq.), touches but lightly upon the dermal system of muscles in the Class ; while even those subsequent writers, Fiirbringer and Gadow, in their well-nigh ex- haustive memoirs in the same field, have by no means given us a complete history of this part of the myological system in Aves (Bronn’s Klassen, vi. Band, 7-22 Lieferung). Such being the case, I find but few authors with whom I can compare notes, bibliographical or otherwise, upon the thirteen muscles described above as considered by me as belonging to the dermal system in Corvus. And I submit them for the most part as they were found to exist in the Raven, B 2 4 THE MYOLOGY OF THE RAVEN. end of this make an incision backwards down to the skull, and posteriorly to well expose the muscles in the upper part of the neck. This straight cut should pass about half a centimetre to the inner side of the upper eyelid of the same side. Reflect the flap of integu- ment thus formed, covering the top of the skull, and carefully examine the under side of it in the median line, where it overlies the frontal region. In old male Ravens, I have here found a true dermal muscle, some 3 centimetres long, and a few millimetres wide, closely attached to the skin. So far, it has not been observed by me in female birds. By its contraction, the median feathers on the top of the head are made to lie very flat ; at the same time those immediately above either eye are elevated, thus giving rise to lateral crests, which are quite well marked. In a captive Raven, an old adult male, I have seen the bird during certain moods make these crests stand up so as to be very evident, not to say conspicuous. 2. The circumconcha.—This is a dermo-osseous muscle which surrounds the periphery of the ear-conch. To expose it, join the longitudinal incision we have already made, and carry the scalpel just through the integument completely around the ear, a few millimetres without its thickened margin ;—then dissect carefully up from all simply inviting attention to the fact that my dermo-temporalis appears to be the second division of the m. cucuLnaris of Gadow; the dermo-dorsalis being also a part of the same; while the platysma myoides of my list is the first division of the m. cucullaris of the same writer ; and finally, my dermo-tensor patagii is the Pans PROPATAGIALIS of the M. cucULLARIS of Firbringer. The skin muscles in the neck of birds have been quite extensively divided up by Gadow and Fiirbringer, described under a superficial and deep set, and in the main as constituting various parts of their m. cucullaris (Bronn’s Klassen, vi. Band, 11 u. 12 Lieferung, p. 21 4). THE DERMAL MUSCLES. 5 sides towards it. As we detach the thickened portion just referred to, it will be found that it contains a dermal circular muscle, closely attached to the skin, but arising in an evident bundle of muscular fibres which have their origin at the outer terminus of the supraoccipital crest (Fig. 7, cc). The ear-conch is further supported by two ligaments, attached at anterior and superior points. 3. The dermo-temporalis.—Extend the longitudinal incision down the back of the neck to a point between the clavicular heads, carrying it just through the skin, and a few millimetres to the left of the median line. Care- fully reflect back the entire flap, removing the skin from the throat and the anterior portion of the chest; and the alar and parapatagial duplicatures of the skin are also to be laid open. A number of dermal muscles are now exposed. One of the most important of these is the dermo-temporalis. On either side it is found to arise by a broad tendinous attachment from a small depres- sion just above and anterior to the temporal fossa. The lower end of this attachment extends down over the sphenotic process, being but slightly wider than it above. From this origin the fibres of the muscle pass directly backwards as a rather broad flat bundle, and make some slight tendinous attachments with the temporal, which it covers. Once clear of the skull, this muscle, as a rather broad and thinnish band of delicate fibres, and intimately connected with the skin, passes directly down the side of the neck, being separated dorsad by quite an interval from the fellow of the opposite side, while anteriorly its margin tends to blend with the fibres of the cleido- trachealis ; indeed a few of its fibres may run in to join this muscular fasciculus. Opposite the shoulder-joint in front the lower ends of the muscular fibres of the dermo- temporalis are lost upon the skin, or blend with the 6 THE MYOLOGY OF THE RAVEN. fibres of the dermo-tensor patagii (to be described further along), or else, as I say, a few of them seem to merge with the cleido-trachealis. This muscle acts as a tensor of the lateral cervical integuments, and through its connection with the dermo-tensor patagii, as an auxiliary to the tensor patagii longus. From such information as I have at hand at the present writing, I would say that the muscle I here describe corresponds to the temporo-alaris of Viallane, or at least to the upper portion of the temporo-alaris of that writer. It has also received other names at the hands of anatomists, as may be seen by consulting their works, or such as deal with the myology of birds. 4. The dermo-dorsalis.—I give the long muscular strip that we find in the Raven, in the median line, running down the neck and back, this name. It is most prominent in the middle of the neck, where it is inclosed in a fold of the integument. It gradually becomes lost as we approach the occiput, as it in like manner spreads out and disappears over the caudal region. Much fat may overlie it, which must be carefully dissected away to bring the muscle into view. By its contraction the feathers along the median line of the dorsum and neck are raised, which action is assisted by the preceding muscle. 5. The platysma myordes.—This muscle is fairly well developed in the Raven, but requires careful dissection to bring it into view. It arises on either side, from the lower margin of the ramus of the jaw, below the ramal vacuity. From these points it spreads out as a very thin, fan-like sheath, closely attached to the skin, to meet in a faint raphe in the median line. It will be seen that the common muscular layer thus formed, materially assists in supporting the lingual apparatus and the upper THE DERMAL MUSCLES. 7 larynx, which are the chief structures found immediately above it. When this muscle contracts, these parts will be compressed and elevated. 6. The dermo-tensor patagii.—That duplicature of the common integument, of a triangular form, which is found in the Raven, as in other birds, between the root of the neck and the top of the shoulder, may be designated as the parapatagiuwm, in contradistinction to the pro- patagium, or the alar integumental duplicature. Lying within the free marginal fold of the parapatagial derme cempytelee, Fic. 1.—Right lateral view of the skull and mandible ot Corvus corax sinuatus, designed to show the origin and insertion of the muscles of the head, &c. Life-size, by the author. ce, origin of the cireumconcha. duplicature in the Raven, we discover a well-developed bundle of muscular fibres, the mesial ends of which spread out, to either become, as a few of them do, inserted into the skin upon the antero-aspect of the root of the neck, or else pass obliquely upwards to blend with the fibres of the dermo-temporalis. This muscle I designate as the dermo-tensor patagii, and externally its 8 THE MYOLOGY OF THE RAVEN. fibres converge, and opposite the outer carneous extremity of the tensor patagii longus they become converted into a small and delicate, though strong tendon, which soon thereafter blends with the tendon of the tensor patagii longus, and in its action plays the part of an auxiliary to it. The dermo-tensor patagii I have already alluded to in various publications, and find in my dissection of birds generally that it is quite a variable muscle; and were these variations all known and appreciated, I am confident that they would be characters of considerable taxonomic value. This muscle seems to correspond to the “ pars propatagialis musculi cucullaris” of Fiirbringer and Gadow, and has by several writers been described as occurring in the species representing a variety of orders of birds. ; 7. The dermo-cleido dorsalis (Fig. 8).—A beautiful pair,of muscles exist in the Raven upon which I have bestowed this name. Either one arises from the upper and mesial aspect of a clavicular limb, to the extent shown in the drawing. As the muscle passes to the integument, it becomes closely attached to it, is directed over the shoulder-joint and scapular region in front, as three distinct fasciculi, diverging ina fan-like form. The extremities may meet in the median line of the dorsum to merge with the dermo-dorsalis. It is very evident that the contraction of these muscles will brace the skin over the fore-part of the back, while if, on the other hand, they act from their integumental attachment, they may aid to a limited extent in the act of inspiration.? 1 These muscles seem to fulfil, in part, the function of the dermo- transversalis of Owen, which I fail to discover in the Raven. This eminent authority describes this muscle for the Apteryx in the following words :—“ The skin covering the dorsal aspect of the lower THE DERMAL MUSCLES. 9 8. The cleido-tracheales.—These muscles are highly developed in the Raven, and seem to take the place of the sterno-maxillaris of Owen.1 Each arises from a two-thirds of the neck, besides being acted upon by the constrictor colli, is braced down by a thin stratum of oblique and somewhat scattered fibres, dermo-transversalis, which take their origin by fascie attached to the inferior transverse processes of the sixth to the twelfth cervical vertebre inclusive; the fibres pass obliquely upward and backward, and are inserted by a thin fascia into the median line of the skin covering the back of the neck” (Anat. of Verts., vol. ii., p. 111). The dermal system of muscles is highly developed in the Apteryx, and this may account for the absence of the sterno-cervicalis in such a form as the Raven, or its occurrence in a very rudimentary con- dition, which I failed to discover. The same author says :—‘‘ The sterno-cervicalis arises fleshy from the posterior incurved angular process of the sternum, from the ensiform prolongation and middle line of the outer and posterior surface of the same bone. The fibres pass forward, and, diverging in gently-curved lines, ascend upon the sides of the broad base of the neck, and are inserted by a thin but strong fascia into the median line of the dorsal integument. This muscle is a line in thickness at its origin, but becomes thinner as it expands ; the anterior part is covered by the posterior fibres of the constrictor colli” (loc. cit., p. 110). Since writing this footnote I ascertain that the sterno-cervicalis of Owen is considered by Gadow to represent the deep layer of his m. cucullaris (Bronn’s Klassen des Thier Reichs, vi. Band, p. 214). 1 «The sterno-masillaris [in the Apteryx] appears at first view to be the anterior continuation of the preceding [sterno-cervicalis], but is sufficiently distinct to merit a separate description and name. It arises fleshy from the anterior part of the middle line of the sternum, passes directly forward along the under or anterior part of the neck, expanding as it proceeds, and gradually separates into two thin symmetrical fasciculi, which are insensibly lost in the integu- ment covering the throat and angle of the jaw. It adheres pretty closely to the central surface of the constrictor colli, along which it passes to its insertion. It retracts the fore-part of the skin of the neck, and also the head. Each lateral portion acting alone would incline the head to its own side; the whole muscle in action would 10 THE MYOLOGY OF THE RAVEN. small circumscribed area situate upon the antero-inner aspect of the middle of either limb of the furcula as a rounded, though not large, bundle of muscular fibres. They take their course directly up the neck, separated by quite an interval. About the middle of their path, they each flatten out and become intimately attached to the skin and the dermo-temporalis muscle. Further along, they become gradually narrower again, and are finally inserted, touching each other by their inner borders, on the anterior aspect of the superior larynx, the trachea, and the skin over these parts. It is only for about their middle thirds that they may be con- sidered as true dermal muscles, and thus account for their appearance in the present category. By their acting in common, or each in turn, movements of the parts would result similar to those described by Professor Owen for the sterno-mawillaris (see footnote, anted). The longitudinal incision which we made down the back of the neck must now be extended, passing only through the skin, to the distal tip of the pygostyle. bend the neck ; but the movements of the head and neck are more adequately and immediately provided for by the appropriate deeper- seated muscles, and the immediate office of the present muscle is obviously connected with the skin. Nevertheless, in so far as this muscle acts upon the head, it produces the same movements as the sterno-mastoideus in Mammalia” (loc. cié., p. 111). Since writing the footnote just quoted from Owen, 1 have ascer- tained (Bronn’s Klassen des Thier-Reichs, vi. Band, pp. 214, 215) that Professor Gadow considers the constrictor colli of Owen to be the superficial layer of the muscle called the cucudlaris by Professor Fiirbringer and adopted by himself, while the dermo-spinalis of Owen constitutes the third division of the same muscle, or the m. cucullaris, pars propatagialis, of Fiirbringer, which, as I have above remarked, is my dermo-tensor patagit.—R. W. 8. THE DERMAL MUSCLES. 11 Reflect back on either side the integumental flaps, as far as the sides and the limbs. Several muscles of the cutaneous system are now exposed in this region. 9. The dermo-spinalis.—This delicate muscle is but Fic, 2.—Superior aspect of the skull of Raven, adult ¢, life-size. Mandible removed. Shows the upper edge of the insertion of the temporal muscle, and that part of the masseter which arises on the zygoma. feebly developed in the Raven, but a little staining in old males will usually bring its fibres into view. It arises in an attenuated fascia from the crests of the 12 THE MYOLOGY OF THE RAVEN. neural spines of the first, second, and third dorsal vertebree, the fibres pass directly outwards, closely attached to the skin, in rather a broad pale stratum, to be lost over the scapular region on either side of the body. 10. The dermo-iliacus is a parial muscle, either one of which arises fleshy from the inner angle of the emar- ginated portion of the antero-dorsal border of the ilium. The fibres pass directly forwards, as a narrow ribbon, to spread out as a thin integumental layer, to be lost over the region of the shoulder-blade. These last two muscles acting from their points of origin would so pull the skin as to cause the feathers attached to it to lie flat, or closer to the body, over the parts where they are severally distributed. In this way they antagonize some of the muscles described above, as, for example, the dermo-dorsalis. | 11. The dermo-ulnaris} is exposed by still further reflecting the skin. It is a very prominent muscle, and 1 This muscle is the PARS METAPATAGIALIS of the M. SERRATUS SUPERFICIALIS 8. THORACI-SCAPULARIS of Fiirbringer, and also of Gadow (Bronn’s Klassen, vi. Band, p. 221), and represents the tensor membrane posterioris ale of Wiedemann and Tiedemann, of Riidinger, of Selenka, and of Carlsson, while Schépss described it in part as the m. plice alaris posterioris. Of it Gadow has said :— “TII. Pars metapatagialis. Dieser Theil ist nach Firbringer als aberrirende zur Haut gehende Lage des Serrat. post. aufzufassen. Er entspringt mit zwei oder drei, selten mit nur einer Zacke zusammen mit den Biindeln der Pars post. serrati von den Rippen, heftet sich an die Hautduplicatur zwischen Oberarm und Rumpf und verliert sich an den oberen Schwungfedern zweiter Ordnung. Der Muskel is demnach ein Theil des weiter unten als M. meta- patagialis zusammengefassten Flughautspanners. [Er findet sich bei Gallus, Anser, Cygnus, Fulica, Otis, Psittacus, Raptores, Cor- vide, u.s.w., fehlt aber den Spheniscide, Tubinares, Ratite ” (Bronn’s Klassen, vi. Band, p. 224). THE DERMAL MUSCLES. 13 one of the most conspicuous of the cutaneous system. It arises by a thin fascia from the outer aspects of the third and fourth true vertebral ribs, at the bases of their epipleural appendages, and from the fascia between them. From this point it passes forwards and upwards as a thick muscular bundle, loosely attached to the skin, until it arrives in a point at the inner end of the integu- mental duplicature behind the humerus. Here it be- comes a small and slender tendon lying between these skin flaps in the line of their posterior margin, as far as the elbow-joint, where the tendon spreads out to become attached to the fascia in the locality, and covering the olecranon of the ulna. By extending the elbow-joint it assists in elevating the wing.! 12. The dermo-humeralis? arises as a broad but 1 Owen describes for the Apteryx a dermo-costalis which “ arises fleshy, from the costal appendages of the seventh and eighth ribs. The fibres pass forward and join those of the preceding muscle [dermo- iliacus] to be inserted into the scapular integument ” (Anat. of Verts., vol. ii., pp. 111, 112). I made several special dissections for the very purpose of finding this muscle in the Raven, but my investiga- tions lead me to believe that it does not exist in our present subject. 2 Fiirbringer and Gadow have divided the mM. PECTORALIS into three parts, and the dermo-hwmeralis as here described for the Raven corresponds to the third part, or the PARS ABDOMINALIS (Fiirbringer). Gadow presents us with the synonymy of the dermo-humeralis as follows :— “IIT. Pars abdominalis (Fiirbringer). Subcutaneus abdominalis. Wiedemann, Tiedemann, § 100, No. 5. #5 Pe Watson, p. 55. Subcutaneus thoracis. Tiedemann, § 100, No. 4. Prechtl, § 71. Ohne Namen erwahnt. Schopss, p. 112. Dermo-humeralis. Owen, p. 24, Panniculus carnosus (second portion). Reid, p. 139. Muscle des parures. Gervais et Alix, p. 401. a 53 Watson, p. 81.” 14 THE MYOLOGY OF THE RAVEN, barely perceptible fan-like muscle in the abdominal integument. This is soon gathered, as it passes forwards and upwards, towards the head of the corresponding humerus, into a decided, long narrow fasciculus of fibres, to be finally inserted by a very pretty little fan-like expansion of thin glistening fascia into the tendon of the pectoralis major just below its insertion. In the Apteryx the dermo-humeralis “is inserted fleshy into the proximal part of the humerus” (Owen). In either case it depresses the humerus in the last-named bird by acting directly upon the bone, while in the Raven it is an auxiliary to the great pectoral muscle. 13. The dermo-pectoralis is a muscle that corre- sponds to the dermo-dorsalis of the back, and is simply the evident muscular stratum underlying the feather- quills of the tracts of these appendages, that are found on either side of the robust chest of this bird, running in the longitudinal direction. Hither of these muscles disappears anteriorly over the origin of the cleido-trachealis, while behind their ter- minal fibres merge imperceptibly into the integument after passing the hinder tips of the postpubic elements of the pelvis. Acting from the anterior skin insertion, these muscles raise the feathers of the chest, the action being reversed by the muscle contracting from the opposite extremity. II. THE MUSCLES OF THE HEAD. INCLUDING THE MUSCLES OF THE LINGUAL APPARATUS, TRACHEA, AND THOSE OF THE EYE AND EAR. Divine the skin completely around the entire beak, at its base ; divide the platysma myoides close to its origin, on either side, and allow its gular portion to come away with the integument as it is removed; in like manner, divide, on either side, close to their origins, the circum- conch and dermo-temporalis. Carefully reflect back- wards the entire skin, so as to expose the neck for at least its upper third. Open the bird’s mouth to its full extent, and pack sufficiently with soft tow, so as to render the muscles of the tongue and trachea more prominent. The muscles here to be examined are the intrinsic muscles of the head, and are in no way attached to the vertebral column. They are the following :— 14, The temporal. 18. The pterygoideus internus. 15. The masseter. 19. The pterygoideus externus. 16. The biventer maxillz. 20. The digastric.1 17. The entotympanicus. 1 This group of muscles (14-20 inclusive) are presented by Gadow in his well-known memoir on the morphology of Aves in Bronn’s Klassen, vi. Band, pp. 318-325, where they are illustrated by 16 THE MYOLOGY OF THE RAVEN. 14. The temporal.—To thoroughly expose this muscle we must divide the strong lateral ligament of the jaw, which is attached above the tip of the squamosal process, and below to the outer side of the articular end of the mandible. The dense fascia encasing the temporal should also be largely dissected away. The bulk of this fan-shaped muscle will be found attached to, and occupying the entire temporal fossa. Anterior to this, some of its more fleshy fibres arise from the mesial side of the sphenotic process, and the adjacent wall of the orbit. From this extensive origin the fibres converge as they pass downwards and forwards, blend more or less completely with the fibres of the masseter as they come opposite to them, to finally become tendinous, to be inserted in the coronoid process upon the superior ramal margin of the mandible. 15. The masseter (Figs. 1 and 7).—This muscle, which may be considered a powerful auxiliary to the one just described, is in the Raven divided into two distinct portions. The greater mass arises by a broad and thin tendon from the entire length of the bony ridge above the auditory entrance, and the squamosal process numerous handsome and useful figures on plates, and an extensive synonymy is given, the latter being somewhat too extensive to reproduce in the present connection. He divides his M. Digasrricus 8. DEPRESSOR MANDIBULZ into three portions (a, Aussere Portion ; 6, Mittlere Portion ; and ¢, Innere Portion), and separately defines them. The temporal has also been somewhat similarly dealt with, having been divided into four portions, with an accessory part. The pterygoidal muscles are given under a single caption, the MM. PTERYGOIDEI. Numerous prominent writers have been omitted in so far as the synonymy goes, though the subject of these head-: muscles has been carefully handled by the author in question. In my description above, I have essentially adopted (for the present) the nomenclature of Owen (Anat. Verts., vol. ii.), though subsequent dissections may incline me to alter or abandon it. THE MUSCLES OF THE HEAD. 17 which extends it. It also has a fleshy attachment to the outer aspect of the body of the quadrate bone. As it passes downwards and forwards beneath the zygoma, it Fic. 8.—Under side of skull of Raven. Life-size. Shows the attachment of the muscles found on this aspect of the skull. By the author. blends with the fibres of the temporal, and makes its first insertion by a tendinous slip to a small tubercle, situated on the upper border of the jaw, behind the c 18 THE MYOLOGY OF THE RAVEN. coronoid process. ‘The great bulk of this division of the muscle, however, passes on to be inserted, fleshy, on the outer side of the ramus of the mandible, nearly as far forward as the horny beak, while behind it is bounded by the prominence of the articular extremity (Fig. 7). Quite a dense fascia encases this division of the muscle. The smaller part of the masseter arises, rather fleshy, from the side and under border of the hinder fourth of the zygoma. This auxiliary and spindle-shaped slip terminates behind in a small, though strong, tendon, which is inserted into the mandible on its upper border, immediately in front of the articular end (Fig. 5, m’). The contraction of this part would draw the jaw against the quadrate, and, to a limited extent, close it. This last action, however, is powerfully effected by the united contraction of the temporals and masseters. Owen says :—‘‘In the Cormorant, the osseous style, movably articulated to the superoccipital, affords to the temporal muscles a more extensive origin. This, indeed, is its essential use, for the muscles of the upper part of the neck are inserted into the occipital bone, and glide beneath the posterior or super-added fasciculi of the temporalis.” 16. The bwenter maaxille, on either side; is that muscular mass which covers the mandibular articulation behind. It arises above from two points, viz. the ridge bounding the hinder part of the osseous ear, and secondly the depression to its mesial side. The two heads almost immediately blend as they pass downwards and forwards, as a curved fleshy mass, to become inserted into the posterior aspect of the articular end of the mandible, including the angle (Figs. 4 and 7). To study this muscle properly it should be transversely divided across its belly at about its middle; the two extremities may THE MUSCLES OF THE HEAD. 19 then be easily dissected up,above, to its origin ; below, to its insertion. The relations of this group, the openers and closers of the jaw, to the surrounding structures, as the ear, the dermo-temporalis muscle, and the quadrate, should be carefully examined. To expose the next set, divide the biventer maxille as already directed, say on the right side; cut the corre- sponding tendon of insertion of the temporal ; divide the masseter as its origin ; and finally disarticulate the man- mplex 0 % c bin. cervicis t yect. cay ant, mMinop ” biventer mamillee ’ rectus capitis posticus major Fic. 4.—Posterior view of skull of Raven. Life-size. Shows the origin of the muscles upon this aspect. After nature, by the writer. dible, lifting the cranium so that we have a plain view of its under side. Matters may be somewhat improved, too, by severing the zygoma at its middle, and pulling the extremities upwards. 17. The entotympanic is a small, spindle-shaped niuscle, which arises quite fleshy from the side of the basisphenoid, and to a limited extent from the base of the rostrum immediately beyond it. As it passes backwards and downwards, it rapidly contracts to form c 2 20 THE MYOLOGY OF THE RAVEN. a double tendinous slip. One of these is inserted into a little spine-like process on the upper side of the shaft of the corresponding pterygoid, close to its quadratal articular end. The other is inserted into the quadrate itself, close to the pterygoidal articulation, and to its outer side. When these muscles contract, they pull forward the quadrates and pterygoids, which latter, in push- ing against the palatines, tend to raise the superior mandible. 18. The pterygoideus internus forms, with the aid of its fellow, the great muscular mass which is found at the roof of the mouth. It has avery extensive origin. On the upper side of the palatine the fibres arise over nearly the entire surface, at first fleshy, to become tendinous along the hinder margin of the bone. Similarly, on the inferior aspect they fill the fossa there found. As the fasciculi of this muscular mass pass backwards and out- wards, they are augmented by others, which find their origin upon the distal head and shaft of the corre- sponding pterygoid and the sphenoidal rostrum for some distance behind it. The fibres converge moder- ately, to make an extensive tendinous insertion upon the antero-internal aspect of the articular end of the mandible. Mesially, they are carried out to the ex- tremity of the inturned tip, where the tendon is very strong; while beyond they encroach slightly upon the ramus, where the insertion is more of a fleshy character (Figs. 5 and 6). 19. The pterygoideus externus is an exceedingly neat and well-defined muscle. It arises from the outer aspect of the extremity of the orbital process of the quadrate., The fibres form a roundish bundle, and slightly diverge as they pass forwards, downwards, and THE MUSCLES OF THE HEAD. 21 outwards, to insert themselves upon the inner aspect of the mandibular ramus, filling the fossa found in front of the articular enlargement, and in which we find the ramal vacuity. This latter foramen is closed in by the pterygoideus externus in this situation, while outwardly the masseter covers it up, the two muscles at this point being practically in contact. 20. The digastric arises on either side from an ellip- tical, longitudinal space, of no great size, situated at the base of the cranium, on the externo-lateral angle of the Lerto-Ryoced, deus ae erent Fic. 5.—Left lateral aspect of mandible of Corvus corax sinuatus, slightly tipped forwards to show muscular attachment on inner side. Life-size. m’, the point of insertion of the zygomatic division of the masseter. basitemporal (see Figs. 7 and 11). From this origin the muscle passes down the side of the neck as a thin, narrow band of fibres. Opposite the angle of the jaw these begin to diverge, and spread out in a fan-like form, to meet a corresponding expansion of the opposite muscle in a median raphe, which extends longitudinally over the superior larynx. They are still more definitely inserted into the cartilaginous continuation of the second basitemporal about its sides. The middle portion of this extremely attenuated muscular stratum is very 22 THE MYOLOGY OF THE RAVEN. difficult to thoroughly trace in the younger specimens of Ravens, and it admits of our seeing the underly- ing structures through it. The delicate fibres of the platysma myoides overlie it, while its anterior fasciculi blend with those of the mylo-hyoideus. According to Mivart, in birds and reptiles the di- gastric descends from the hinder part of the cranium to the. posterior end of the mandible, and in some birds is divided into three portions (Elem. Anat., p. 313). As we have just seen, it is still different in the Corde. The chief use of this muscle would seem to be to raise the hyoid apparatus and trachea against the pha- rynx, after a morsel of food has passed that point, to prevent its return to the mouth, and assist its passage down the cesophagus. III. THE MUSCLES OF THE TONGUE. In this section I will speak of those muscles of the Raven which I have found upon dissection to be, in Fic. 6.—Under side of mandible of a Raven, designed to show the sites of muscular attachment ; life-size, from the author’s dissections. some way or another, attached to the hyoidean apparatus, and involved in its movements. 24 THE MYOLOGY OF THE RAVEN. In Fig. 7, and other illustrations to this work, I have made careful drawings of these parts, and en- deavoured to present this group of muscles in such a manner as they can best be seen and studied. The following are presented for our examination :— 21. Mylo-hyoideus. 25. Sterno-hyoideus. 22. Stylo-hyoideus. 26. Depressor-glossus. 23. Genio-hyoideus. 27. Cerato-glossal. 24, Cerato-hyoideus. 21. The mylo-hyoideus! (Figs. 5, 11, and 17).—This muscle arises on the inner side of the mandible, just above 1 Professor Hans Gadow sees two parts to the mylo-hyoideus in birds, his M. MYLO-HYOIDEUS ANTERIOR corresponding to my mylo- hyoideus, as shown by me in Fig. 11 of the present work (see Bronn’s Klassen, vi. Band, pp. 304-307). To me, the M. MYLO-HYOIDEUS POSTERIOR of Gadow did not seem to be sufficiently evident in the Raven to merit a separate descrip- tion, and it is in no way so distinct a muscle as he figures it in Rhea -darwini (ic, Fig. 1, M.H.p., p. 306). Nevertheless, it has been variously considered by other ana- tomists, and Gadow offers us the following synonymy and remarks thereon :— “103. I. Grupe des M. myLo-Hyorpeus. 1034. M. MYLO-HYOIDEUS ANTERIOR, M. genio-hyoidean. Vicq d’Azyr, 1773, p. 585, No. 1. Mylo-hyoidean. Cuvier. Duvernoy, p. 5, No, 1. 55 Gervais et Alix, p. 19. Mylo hyoideus transversus. Tiedemann, § 90, No. 1. % Nitzsch, p. 134, No. 2. Mylo-hyoideus obliquus. Kutorga, p. 20. Rhomboideus juguli. Wiedemann, p. 70. Querer Unterkiefermuskel oder vorderer, oberflichlicher Kiefer- Zungenbeinmuskel. Meckel, p. 409, No. 2. Mylo-glossus s. transversus mandibule. Gurlt, p. 14. Mylo-hyoideus. Schneider, p. 145 ; Gadow. +5 Watson, p. 136. “ Dieser Muskel erscheint nach Abtragung der Haut zwischen den beiden Unterkieferisten. Er entspringt von der Innenfliche, oder THE MUSCLES OF THE TONGUE. 25 the lower border and the inturned edge of the horny sheath of the bill. The line of its origin occupies about auch vom Rande des Unterkiefers mit ganz quer gerichteten Fasern, die sich in der Mittellinie mit denen der anderen Seite unter Bildung eines longitudinalen Schnenstreifens vereinigen. Ge- wohnlich hat der Muskel keine direkte Verbindung mit dem Zun- genbein.”” [This is followed by an account of its variations in a number of groups of birds. ] “103B, M. MYLO-HYOIDEUS POSTERIOR. Mylo-hyoidien. Vicq d’Azyr. Serpihyoidien. Cuvier. ” Duvernoy. Retrahens lingue. Wiedemann, p. 71. Mylo-hyoideus obliquus. Tiedemann, § 90, No. 2. 4 is Kutorga, p. 20. $5 hos Nitzsch, p. 135, No. 4. Heber des Zungenbeins. Meckel, p. 409, No. 1. Mylo-hyoideus. Gurlt, p. 14. Retractor de UVhyoide ow serpi-hyoidien. Gervais et Alix, p. 18. Serpi-hyoideus + Stylo-hyoideus. Gadow, pp. 66, 67. Retractor lingue. Watson, p. 135. “ Halswirts vom M. mylo-hyoideus, ebenfalls subcutan gelegen zerfallt dieser, grosser Verschiedenheiten zeigende Muskel, bisweilen in zwei Theile. Bei hea darwini entspringen beide zusammen von der Aussenfliche des hinteren Ende des Unterkiefers, laufen iiber die nach Aussen iibergreifende Insertion des J. pterygoideus, werden breiter urd theilen sich in eine vordere und eine hintere Masse. Die letztere (M. serpi-hyoideus) geht mit ziemlich trans- versaler Richtung zur Mittellinie ; ihre tieferen Ziige befestigen sich am Bindegewebe der Ventralfliche des Larynx, die oberflichlichen vereinigen sich aponeurotisch mit denen der anderen Seite und strahlen zugleich auf den Hinterrand des M. mylo-hyoideus, sowie halwirts auf den UW. constrictor colli aus. Die vordere Masse (I. stylo-hyoideus) ist schmaler, geht schrig vorwirts und einwiirts und inserirt sich in dem von den beiden Zungenbeinhérnern und dem _ Zungenbeinkérper gebildeten Winkel; der Insertionstheil wird ventralwirts vom Jf. mylo-hyoideus anterior bedeckt.” After giving its variations in a number of groups of birds he adds that “Bei Corvus kommt der gemeinsame Ursprungstheil 26 THE MYOLOGY OF THE RAVEN. the anterior third of the entire length of the ramus, and is carried forward to the posterior margin of the horny covering of the beak, where the latter overlaps the symphysis. Its wonderfully delicate fibres are di- rected transversely to meet those of the muscle coming from the opposite side. The two unite in a mid-longi- tudinal raphe, which as it is produced backwards be- comes faintly tendinous, and is finally inserted as an attenuated aponeurosis into the under side of the hyoid, between the first and second basibranchial, in the middle line (Fig. 17). The thin sheet of muscle thus formed spans and stretches completely around the forepart of the inter- ramal space, and by its contraction the tongue is lifted upwards against the roof of the mouth. This muscle is well developed in other classes of animals. Professor Mivart found it very large in Meno- poma, and it varies considerably among the higher Mammalia. 22. The stylo-hyoideus is the name used by Professor Owen for a muscle which is quite conspicuous in the Raven. Its origin and insertion are well shown in Fig. 7, where the lingual apparatus is drawn down by the dissecting chains, in order to put it on the stretch (see various views of the mandible, where it is shown). The stylo-hyoideus arises on the outer aspect of the articular enlargement of the mandible, at about the middle point. Its fibres form a rather long, transversely hauptsichlich von der 4usserlich den M. biventer mandibule. bedeckenden Fascie.” Having carefully dissected the mylo-hyoideus out in some fifteen specimens of the Raven, it seems but proper that I should say here that my observations upon it agree with those of Owen, and in the form in question I have thus far failed to detect a posterior mylo- hyoideus (see Owen’s Anat, Verts., vol. ii, p. 153), THE MUSCLES OF THE TONGUE. 27 flattened fasciculus, which proceeds downwards and forwards to be inserted by a delicate tendon into the head of the cerato-branchial of the thyro-hyal of the corresponding side on its upper aspect. When these muscles contract in unison, they tend to raise the tongue towards the palate, but if they act singly this member is pulled to the side towards which the contracting muscle is directing it. We find that “in some birds it divides into three or more portions: the posterior descends obliquely forward, and is inserted into the tendinous commissure of the mylo-hyoideus ; the middle portion is inserted into the urohyal [second basibranchial]; the anterior fasciculus is inserted into the side of the basihyal above the transverse hyoglossus. The actions of these different portions vary according to their in- sertion ; the first and second depress the apex of the tongue by raising the urohyal, the third raises the tongue and draws it to one side when it acts singly ” (Owen). 23. The genio-hyoideus is the largest and most powerful muscle of the group we are now examining (Figs. 5 and 7, and others). It arises from an extensive area (two in some birds) on the inner side of the mandible nearly as far forward as the horny part. The fibres unite to form a broad band, transversely compressed, which passes downwards and backwards until it meets the outer side of the corresponding thyro-hyal, about its middle ; this it envelops, by a spiral turn and a half, to its very extremity. It is quite evident that the contraction of this pair of muscles will have the effect of protruding the tongue from the mouth. 24. The cerato-hyoideus (Figs. 7 and 9).—I find the muscle so named by Owen to have a somewhat differ- ent insertion than that eminent anatomist gives it for ‘ ‘ayIT JO az[s eINBLY ‘SUOTJOISSTP UO STY VIO oye oy} Aq UMBIGE “BYOUOIUIMITD Jo UISTIO ‘99 -‘snUIa{UL sneplosArojd 94} J0AO JORIUT SUTEULAL [[IS JOULIO} ey} JO WoIsuazxe IeUUTY} OY} pe ‘Yo axe} Us9q JOU 9ABY oNsU0y pu Yvoq Jo ssUIIeA00 AUIOY oY, ‘eposnut Terodur9} sy} MOYS 0} 197I0q OY} ‘padoter usEq sey vf oy} Jo JUauTeSIT [e102] Ot} PUS ‘UMOYS ][oM eI oJOSSUT aT{} JO SMOISTAIP OM} OY], “OLIISBSIp 94} Oprse qind pue ‘T{]09 royo1ysu09 043 dn nd ‘onSu0} ey} umop [ud A]qror10J sureyo Sunoasstp [eug “prody oq} Jo esoyy SB ][oM se “qoodse sty} Lodn sopsnut oY} MOUS 0} Poyossip Woaq sey YOIYM ‘USAEY v Jo PY JO META [RIOYUL FYSIY—") “OTT THE MUSCLES OF THE TONGUE. 29 the class, generally. Of it, he says that “it passes from the thyrohyal to the urohyal, and is therefore sub- servient to the lateral movements of the tongue” (Anat. Verts., vol. ii. p. 154), This duty it also performs in the Raven, where we find it arising on the under side of the shaft of the epibranchial element of the thyro-hyal by a delicate tendinous slip. This soon becomes muscular as it passes forwards, forming a long slender belly, which is closely applied. to the hyoid. Opposite the first basibranchial it is again a long tendinous slip, and. thus remains until it is finally inserted into a little bony elevation on the under side of the anterior end of the corresponding cerato-hyal. Owing to the free lateral movements enjoyed by the joint at the anterior end of the first basibranchial, it is quite clear that either of these muscles acting singly must pull the tongue to one side. But the joint referred to also operates in the opposite direction, so that, united action of the pair would tend to depress the tongue. 25. The sterno-hyoideus (Figs. 9 and 17).—Agreeing with the majority of birds, we find in the Raven either sterno-hyoideus arising from the anterior surface of the thyroid bone of the superior larynx. The muscular fibres at the origin are quite fleshy, but as they converge and pass forwards, they become rather more tendinous, and are thus constituted as they are inserted into either cerato-hyal at its base. Other fibres, which hold a more mesial position, unite with the corresponding ones of the muscle of the opposite side, to pass into and finally be lost in the tissue composing the soft part of the tongue, at its base. ‘hese latter are not well shown in Fig. 17, as they are huddled together by the traction of the little dissecting hook and chain, which pulls the muscle to one side so that the depressor glossus may be seen. 30 THE MYOLOGY OF THE RAVEN. If these muscles contract in unison, the larynx being the fixed point, they will evidently depress the tongue. Acting singly in the same way, either one will likewise depress the tongue, but also give it a lateral deflection to the side towards the muscle which is contracting. If they contract together, with the base of the tongue as the fixed point, they will pull the larynx forwards, a very necessary movement during the accomplishment of the act of deglutition. 26. The depressor-glossus is the name | have bestowed upon a small but important muscle which Professor Owen describes in the following words: “A small and short muscle, which is single or azygos; it passes from the basihyal to the under part of the glossohyal ; it depresses the tip of the tongue and elevates its base” (loc. cit., p- 154). Nameless though he left it, Professor Owen’s description answers very well indeed for a corresponding muscle that we find in the Raven, and the one, as I say, iE propose to call the depressor-glossus. In this bird it arises fleshy over the entire under surface of the first basibranchial (basihyal of Owen), the fibres contract as they pass forwards, and become tendinous between the tongue bones, and as a delicate tendon so continue on to finally find an insertion at their tips, where they meet anteriorly (Fig. 17). When this muscle contracts, the tongue must behave in a manner already described, and quoted from the authority above. 27. The cerato-glossus is a small muscle we find on the upper side of the hyoid, one on either cornua. Each occupies, as an origin, the half of the surface of the first basibranchial. After passing over the joint formed by the head of the thyro-hyal, the fibres become. more tendinous, as they insert themselves along the upper side of the shaft of the cerato-branchial element. They dermo-cleido dorsalis tensor patagii (tongue te Gen) deltoid "azo, eovoralis serratas magrurs Fig. 8.—Oblique view from the inner side of the furcula, coracoid, and scapula of the Raven, showing the areas devoted to the muscles which take origin from these bones. Life-size. Fic. 9.—Under view of the hyoid arches of a Raven, with the upper part of the windpipe, in situ. Designed to show the origin and insertion of certain ae of the tongue. m.h., lingual attachment of the mylo-hyoideus. ife-size. Fic. 10.—Superior view of the bones of the upper larynx and half-rings and tings of the trachea. Shows the origin and insertion of the two muscles which control the rima glottidis. x 2. All the figures drawn by the author from his own dissections. z THE MYOLOGY OF THE RAVEN. eruvcad Fascia overed, by the ce rot? )° mv Fic. 11.—Under view of the head of a Raven, with mandible zm széu, but with hyoid apparatus and other parts carefully removed. Dissccted to show the muscles which occur upon this aspect ; the left side (the right in the figure) shows the origin and insertion of the pterygoideus internus. The opposite side is dissected to show the entotympanicus and plery- gotdeus cxternus, The anterior two-thirds of the mylo-hyoidcus is also shown, and its mode of attachment. The digastric is cut off close at its point of origin. This figure should be carefully compared with Fig. 3 of the present memoir. Life-size, by the author from his own dissections. here glide beneath the thyroid bone of the superior larynx. Just beyond this point they become fully THE MUSCLES OF THE TONGUE. 33 tendinous, and are finally inserted as a distinct tendon at the muscle’s termination on the shaft of the element just alluded to, and in line with the last-named fibres. According to Professor Owen, Dr. Salter proposed the name of this muscle which I have here adopted for it. The former anatomist describes it as “a short muscle, which arises from the junction of the basihyal with the urohyal, and is inserted into the thyrohyal” (loc. cit., p. 154). Professor Owen figures it in a Fieldfare, but makes an incorrect reference to his figure, and the muscle is shown, apparently, as being pulled out of its normal position, in order to show the stylo-hyoideus. When these muscles contract, they will elevate the long cornua of the hyoid arches, and press them up against the skull. In addition to the muscles already described as be- longing to the tongue, there is still another pair, found by Owen in a Woodpecker (shown in Fig. 12 at h), which he has named the cerato-tracheales, and says: “They arise from the trachea about eight lines from the upper larynx, twist four times spirally round the trachea, and then pass forward to be inserted into the base of the thyro-hyals. This is the principal retractor of the singular tongue in this species” (Anat. Verts., vol. ii., p. 154). Unfortunately, Professor Owen does not mention in his work the species of Woodpecker in which he found this interesting pair of muscles. He speaks of it, however, in such a way as to lead one to suppose that it occurs throughout the family. Dissections made upon our American forms, with a view of looking further into this matter, would be well worth the time and labour of the comparative anatomist. D 34 THE MYOLOGY OF THE RAVEN, Referring again to Professor Gadow’s estimable work in Bronn’s Klassen des Thier-Reichs (vi. Band, pp. 307-317), we find that he has described and proposed the following nomenclature for the muscles of the lingual apparatus in birds. In presenting this I refer to the plates of this writer, although his figures are not here reproduced. It will be observed that he has bestowed very different names upon the muscles as compared with Owen’s nomenclature, the authority at my hand when the present volume was written. “TI. Muskeln des Zungengeriistes. (Taf. xxxii., xxxiii., und Holzschnitte.) “104, System pes M. sTerNo-HyoIDEus. Thyreo-hyoideus. Vicq d’Azyr ; Gervais et Alix, p. 18. M. laryngo-hyoidei. Tiedemann, § 90, No. 5. Hyo-thyreoideus. Kutorga, p. 20. Gurlt, p. 15. Thyreo-hyoideus. Nitzsch, p. 136, No. 5. Thyreo-glossus. Nitzsch. Thyro-hyoid. Watson, p. 136. M. ypsilo-trachealis s. depressor arterie aspere superficialis, major. Meckel, 6 Theil, p. 284. : Sterno-hyoideus. Nitzsch; Gurlt, p. 15. Tracheo-sternalis, Gadow, Tenuirostres, p. 68. Omo-thyreoidet. Huber. Les cerato-trachées. Cuvier. Cerato-trachei. Tiedemann, p. 122. Tracheo-glosst. Huber. Cerato-trachealis. Owen. Tracheo-hyoidien. Duvernoy. Tracheo-hyoideus. Gadow, p. 62. “ Hin echter, an das bei den Reptilien allgemeine urspriingliche Verhalten anschliessender M. sterno-hyoideus ist noch bei Apteryx vorhanden. Der breite Muskel entspringt vom vorderen Rande der Unterfliche des Thyreoid-Knorpels des oberen Kehlkopfes und vom ganzen Innenrande der Zungenbeinhirner. Seine Fasern sind abwirts gerichtet, verbinden sich theilweise mit denen der anderen THE MUSCLES OF THE TONGUE. 35 Seite in der ventralen Mittellinie und bilden dann eine ziemlich dicke und breite Muskellage, welche ventral und seitlich die Trachea lose umgiebt, ohne jedoch an derselben befestigt zu sein. Nahe der Brust angelangt, theilt sich die bis dahin vereinigte Masse in eine rechte und eine linke Hilfte, deren jede sich am ganzen Seitenrande des Sternums und auch am gréssten Theile des hinteren oder caudalen Randes des Brustbeines inserirt. Die Brust- und Schultermuskeln werden natiirlich von den theilweise aponeuro- tisch gewordenen, flachen Insertionstheilen des MU. sterno-hyoideus bedeckt. “ Der Muskel wird durch Zweige des WV. hypoglossus, und weiter abwarts von den meisten Cervicalnerven aus innervirt. « Als eine mediane, innere, von dem eben beschriebenen Muskel abgetrennte Masse ist ein Muskel aufzufassen der bei Apteryx mit geringer Ausdehnung fleischig vom Coracoid, nahe dessen Verbin- dung mit dem Sternum entspringt und sich streng median- und kopfwarts gerichtet, etwas oberhalb der Theilung der Trachea in die Bronchien an der Trachea befestigt ; von dort begleitet er die Trachea, an derselben seitlich besfestigt, wird im Bereich des oberen Drittels der Luftroéhre sehr schwach, schwillt aber nahe dem Thyreoidknorpel wieder an und inserirt sich an dessen Seiten- und Unterfliche. Wir bezeichnen ihn als J, sterno s. coraco-thyreoideus. Dieser Muskel wird ausschliesslich durch einen Ast des WV. hypoglossus innervirt, der bis in die Brust hinabsteigend in dem Muskel verfolgbar ist. “« Andere das Sternum und den Schultergiirtel mit der Trachea oder mit dem Zungengeriist verbindende Muskeln besitzt Apteryx nicht. Das bei diesen Ratiten bestehende Verhiltniss giebt uns Aufschluss iiber die complicirteren Zustande bei den andern Vogeln. Aus den beiden Muskeln des Apterya sind mehrere entstanden, von denen aber nur die mit dem Zungengeriist in Verbindung stehenden hier besprochen werden, wihrend die iibrigen, als in den Dienst der Respiration und Stimmbildung getreten, bei jenen Organen er- schépfend behandelt werden. Ein J. sterno-hyoideus findet sich ausser bei Apteryx bei manchen Carinaten. Bei Prosthemadera wird er jederseits durch ein schmales Band gebildet, welches im Winkel der Symphyse der Furcula entspringt und direkt, ohne andre Verbindungen einzugehen sich an der Basis des Zungenbeins und zwar mehr an dessen Dorsalseitenrand inserirt ; nur wenige Fasern befestigen sich an der Wurzel der Zungenhérner. “ Bei Meleagris ist nur die bei Apteryx als innere erwihnte mediane D2 36 THE MYOLOGY OF THE RAVEN. Portion vorhanden. Dieselbe kommt vom Proc. lateralis anterior des Brustbeins, geht zur Seite der Trachea, wird sehr schwach und schwillt am obern Ende wieder an, um sich am Larynx und am Os urohyale zu befestigen ; ausserdem aber ist sie nahe dem Larynx an jeden der Trachealringe befestigt, oder eigentlich kommt von diesen Ringen und geht zum Urohyal, den benachbarten Theilen des Basihyal und der Zungenhérner. Als eine deutliche Abspaltung des angen Muskels besitzt MJeleagris noch einen, der sich vom ventralen und seitlichen Rande des Thyreoidknorpels und vom Seitenrande des ersten Trachealringes selbstandig und frei an der Seite des Halses her abzieht, in der Nahe der Schulter aber ventralwirts mit dem der anderen Seite convergirt und eine sehr diinne, ziemlich schliipfrige Schicht von Bindegewebe ohne Muskelfasern Dildet, die sich allmilich an der Ventralfliche des untern Endes der Luftrébre anheftet. Diese beiden langen Muskeln von Meleagris werden von einem Zweige den WV. hypoglossus begleitet. “Denkt man sich nun, wie das iibrigens schon bei Apterya und Meleagris angedeutet ist, dass die Fasern des Jf. sterno-hyoideus und claviculo-hyoideus im Bereich des mittleren Halsdrittels verkiim- mern, so zerfallen ebengenannte Muskeln je in einen obern Theil, der dann als tracheo-hyoideus und tracheo-laryngeus superior und in einen untern Theil, der als sterno- s. coraco- s. cleido-trachealis und tracheo-laryngeus inferior betrieben werden kann. Jeder derselben kann wieder in Unterabtheilungen zerfallen. ‘So haben wir bei Rhea folgende Muskeln: 1. Ein UM. tracheo- aryngeus superior. Derselbe erstreckt sich von der Ventralfliiche des Hinterrandes des Thyreoids auf die Seitenfliche des obern Drittels der Z'rachea. 2. Sein vorderster Theil ist ein Thyreo-glossus s. hyoideus, denn er verbindet die Ventralfliche des Zhyreoids mit dem Hinterrande des Os basihyale. 3. Von der Seitenmuskulatur der Trachea lést sich ein wohlentwickelter bandartiger Muskel ab, der sich am obern Ende des ersten Gliedes des Zungenbeinhornes befestigt, daher Jf. tracheo-hyoideus zu nennen ist. 4. Die Brust- partie derselben Muskelmasse ist sehr diinn geworden und verliert sich in der Haut des Halses, ohne mehr die Brust zu erreichen. Ausserdem ist 5, ein Sterno-trachealis vorhanden und ein daraus differenzirtes Paar Syrinx-Muskeln. “Bei MNycticorax griseus besteht ein dem M. tracheo-hyoideus und thyreo-hyotdeus von Rhea vergleichbares Muskelpaar, das mit einigen Ziigen von der Trachea, hauptsichlich aber vom Thyreoid- Knorpel zum Basihyal geht. Die Luftréhre wird nicht von Mus- THE MUSCLES OF THE TONGUE. 37 keln begleitet, die betreffenden Theile sind daher ausgefallen, und nur ein M. sterno-trachealis nebst einem primitiven Syrinxmuskel oder M. tracheo-bronchialis ist vorhanden. “Bei Cacatua roseicapillus kommt ein diinnes Muskelband vom Larynx und vom Zungengeriist ; ein Theil begleitet die Luftréhre bis zu den Syrinx- und Tracheo-clavicular-Muskeln und wird wie diese nur vom JV. hypoglossus innervirt ; ein dickerer, mehr seitlicher Theil breitet sich bald auf der Halshaut aus, verwebt sich dort mit den Hautmuskeln und erreicht das Brustbein oder den Schulter- giirtel nicht. Hauptsiichlich von einem langen Zweige des J. hypoglossus versorgt, erhalt er weiter unten auch Zweige aus den Cervicalnerven. “ Beim Griinspecht (Taf. xxxiii., Fig. 354) [not here reproduced], kommt jederseits ein diinner Muskel vom Schultergiirtel, begleitet die Trachea in ihrer ganzen Linge und stisst erst nahe dem Kehl- kopfe mit dem der anderen Seite zusammen, worauf sich beide am Thyreoid und dem medianen Zungengeriist inseriren.—Ein zweiter Muskel kommt von der Clavicula und geht etwas seitlich von dem vorigen gerade kopfwiirts als ebenfalls schmales Band und inserirt sich am Thyreoidknorpel und am Grunde des Zungenbeinhornes seiner Seite. “Hin dem JM. tracheo-hyoideus entsprechender Muskel erreicht bei den Spechten seine héchste Entwicklung. Er entspringt jederseits von der Trachea unterhalb des Kehlkopfes, windet sich dann mehrere Male (beim Griinspecht viermal) lose um die Luftréhre und geht dann an die Basis des Zungenbeinhornes. Bei weit herausgestreckter Zunge entrollt sich dieser eigenthiimliche Miiskel seine Funktien ist Zurriickziehen der Zunge. “Wir koénnen daher diejenigen Zungenmuskeln, welche entweder mit dem Brustbein und Schultergiirtel, oder mit der Luftrohre und dem oberen Kehlkopfe zusammenhingen, folgendermassen zusammen- fassen, “T. Gruppe. “Vom Sternum zum ganzen Zungenhorn, und zum Basihyal : Sterno-hyoideus ; Apteryx. “Von der Clavicula hauptsichlich zum Zungenkérper ; Cleide- hyoidet ; Prosthemadera, Ptilotis, Pici. “ Dieselben Muskeln erreichen aber die Brust nicht, sondern sind an der Halshaut befestigt ; Papageien. “TI. Gruppe. “Von der Trachea zum Zungengeriist und zwar zum Cerato-hyal ; 38 THE MYOLOGY OF THE RAVEN. Tracheo-hyoidei ; Nectarinia; Pici; Gralle; Rasores ; Raptores : Rhea. “Vom Larynx (Thyreoid) und theilweise auch von der Trachea zum Basihyal, Entoglossum und Urohyal ; Thyreo-hycidet ; Anser ; Gallus: Rasores:; Ptilotis ; Rhea ; Spheniscide. “105, M. @ENIO-HYOIDEUS. M. genio-hyoides. Steno. Le muscle conique de Vos hyoide. Vieq de Azyr, 1773, p. 535. Protahens lingue. Wiedemann, p. 71. Mm. conici ossis hyoidei. Tiedemann, § 90, No. 3. a # Kutorga, p. 20. Tiefer Vorwiirtzicher oder Kinnzungenbeinmuskel. Meckel, p. 409, No. 3. Mylo-cerato-hyoidien. Duvernoy. Genio-hyoideus. Gurlt, p. 15. 3 Nitzsch, p. 135, No. 3. 3 Gadow, Tenuirostres, Proe. Zool. Soc., 1883, p. 67- Mylo-ceratoideus anterior et posterior, Nitzsch, in seiner Tafeler- kidrung, p. 151. Genio-ceratoideus. Huber. Protracteur de Uhyoide (genio-hyoidien). Gervais et Alix, p. 18. Protractor lingue. Watson, p. 135, “Dieser Muskel entspringt vom inneren, unteren oder vom oberen Rande des Unterkieferastes, ungefiihr in dessen Mitte und geht bandférmig gerade nach hinten, ventral von dem JM. mylo-hyoideus anterior, aber dorsal oder in der Tiefe von I. mylo-hyoideus posterior gelegen, an die vorwirtsschauende Seite der Zungenbeinhérner, um die er sich theilweise herumwindet ; ihr Enddrittel ist ganz von den Muskelfasern umgeben. So verhilt es sich bei vielen Vogeln, z.B. bei Corvus, Anser, Procellaria, Spheniscus. Hiufig jedoch (WNec- tarinia, Otis) zerfallt das vom Unterkieferkommende Band in zwei, von denen das eine sich wie gewdhnlich um das Zungenbeinhorn herumwickelt, wihrend das andere sich nur an der ausserten Spitze desselben befestigt, beide Theile sind aber von einer gemeinsamen schliipfrigen Scheide umgeben, wodurch ihr Zusammenwirken und zwar ausschliesslich in der Richtung des Knochens, gesichert ist. Bei Prosthemadera war der Ursprung des Bandes auf die Aussen- flache des Unterkiefers geriickt. “ Bei den Papageien ist der Muskel ganz getheilt. Der vordere (Taf. xxxii., Fig. 30p) [not re-figured here] entspringt vorn an der THE MUSCLES OF THE TONGUE. 39 inneren Fliiche des Unterkiefers und geht zum letzten Drittel des ersten langen Gliedes des Zungenbeinhorns, erstreckt sich auch wohl etwas zum zweiten, umwickelt aber bei Papageien das Zungenbein- horn nicht so wie bei vielen andern Vogeln. Der hintere Theil (Fig. 30c) [not re-figured here] entspringt weit vom vorderen ent- fernt am unteren Rande des Unterkieferastes etwa in der Mitte seiner Linge und geht an das sehr kurze zweite Glied des Zungen- beinhornes seiner Seite. Nitzsch schlagt fiir diese beiden Muskel- theile die Namen M. mylo-ceratoideus anterior und posterior vor. Bei Rhea sind ebenfalls zwei ganz getrennte Binder vorhanden. Das vordere entspringt aus dem Kinnwinkel und stiésst in der Mit- tellinie mit dem der anderen Seite zusammen ; es inserirt sich am Ende des ersten Gleides des Zungenbeinhornes. Das iussere Band ist schmiiler und wickelt sich um die iiusserste Hilfte des letzten Gliedes des Zungenbeinhornes. “106. M. GENIO-GLOssUS. M. myloglosse. Duvernoy, p. 6, No. 5. MM. genioglossus. Nitzsch. “ Dieses Muskelpaar scheinen nur wenige Végel zu besitzen. Bei den Papageien entspringt es vorn dicht neben der Mittellinie der inneren Kinnflache, wird vom JM. mylo-hyoideus bedeckt und begibt sich als diinnes Band an den Seitenrand des hinteren Endes des Os entoglossum. Nach Nitzsch fehlt es bei vielen anderen Vogeln, oder es ist, wie bei den Raubvégeln, wo es im Frenulum der Zunge vom Rachen aus durchscheint, so schwach, dass es leicht tibersehen wird. “Den Penguinen, Trappen, Gansen, Krahen, Hiihnern, Spechten Kolibris, Nectarinien scheint es in der That zu fehlen. “Bei Procellaria ist der Muskel sehr diinn, liegt der Mundschleim- heit an, und erstreckt sich vom seitlichen hinteren Theile des Os entoglossum diinner werdend und mit dem der andern seite con- vergirend zum Kinn.” “107. M. cERATO-GLOsSUS. Cérato-glosse. Cuvier. Cérato-glosse. Duvernoy. Cerato-glossus. ‘Tiedemann, § 91, No. 1. ue Kutorga, p. 21. 40 THE MYOLOGY OF THE RAVEN. Cerato-glossus. Watson, p. 134. i Gadow, p. 67. Nieder- und Seitwartszieher der Zunge. Meckel, p. 408, No. 1. Ceratoglossus inferior s. basioglossus lateralis und superior. Nitzsch, p. 136, 137. Basioglossi inferiores et superiores. Kutorga, p. 21. P’hyo-glosse. Gervais et Alix, p. 18. Grund-Zungenmuskel (basio-glossus). Gurlt, p. 15. Griffel- oder Zungenbein-Zungenmuskel (stylo-hyoideus). Gurlt, p. 15. “Im allgemeinen entspringt dieser stets vorhandene Muskel fleischig von der oberen Fliche des ersten Abschnittes des Zungen- beinhornes und inserirt sich mit einer langen, deutlichen Sehne am Seitenrande des Os entoglossum. Hiiufig zerfallt er in zwei Theile ; der eine kiirzere geht bei den Hiihnern vom Zungenkérper (Os en- toglossum) bis fast zur Spitze der Zunge, die er herabkriimmt, er liegt dann auf der Ventralseite der Zunge; der andere lingere kommt vom Zungenbeinhorn und endigt sehnig am Grunde des Korpers.” [This account of the cerato-glossus (the cerato-glossal as described by me above for the Raven) is completed by Gadow by a few words upon its variations as found by him in a number of groups of birds. ] “108. M. ceraTo-HYOIDEUS. Cérato-hyoidien. Cuvier. Cerato-hyoideus. Tiedemann, § 90, No. 4. oi Kutorga, p. 21. 55 Meckel, p. 409, No. 4. rs Nitzsch ; Gurlt, p. 14. “4 Duvernoy. Cératoidien transverse. Gervais et Alix, p. 19. Cerato-transverse muscle. Watson, p. 134. “Ein kurzer Muskel, der fleischig von der Innenseite des ersten Stiickes des Zungenhornes entspringt und mit schrig vorwiirts und median gerichtetem Verlauf an den unpaarigen Stiel des Zungen- geriistes (Os urohyale) inserirt, haufig verbinden sich dabei die gegenseitigen Muskelziige. “Verwebung mit dem ventral gelegenen M. mylo-hyoideus pos- terior ist gewohbnlich.—Fehlt aus Os urohyale, wie bei Rhea und bei Platalea, so ist auch der Muskel nicht vorhanden, letzteres gilt aber ‘THE MUSCLES OF THE TONGUE. 41 auch bei vielen Végeln, welche wie der Flamingo, Storch, manche Raubvégel, Prosthemadera, Nectarinia den unpaarigen Stiel be- sitzen. “ Bei Eudyptes chrysocome ist der Muskel recht lang; er kommt vom zweiten Drittel des Zungenbeinhornes und verbindet sich auf dem Urohyal mit dem mylo-hyoideus. Er scheint eine den Végeln eigenthiim-Differenzirung des UM. cerato-glossus zu sein. «109. M. HYPoGLossus. “ Jederseits aus einem oder zwei Muskelchen bestehend, die von der Unterfliche des Os basihyale entspringen und neben einander auf der Unter- und Seitenfliche des Os entoglossum sich inseriren. Sie werden durch einen Zweig des Ramus lingualis WV. hypoglossi innervirt und sind héchstwahrscheinlich als tiefere, etwas selbstiindig gewordene Theile des WU. ceratoglossus aufzufassen. “a. M. Hypoaiossus OBLIQUUS.. Hyoglosse transverse. Cuvier; Duvernoy. Hyoglossus obliquus s. parvus. Tiedemann, § 91, No. 2. 3 + es Gurlt, p. 15. Heber der Zunge. Meckel, p. 408, No. 2. Hypoglossus obliquus. Nitzsch. Hyoidien transverse. Gervais et Alix, p. 18. Transverse hyoid muscle. Watson, p. 136. “ Jederseits ein kleiner Muskel, der vom Ceratoglossus bedeckt wird ; sie entspringen nebeneinander von der unteren Fliche des Zungenbeinkérpers (Basi-hyal) mit schiefen Fasern, schlagen sich um dessen Seitenrand und setzen sich an den hinteren Seitenrand des dem Basi-hyal aufsitzenden Os entoglossum oder Zungenkern. Bei Procellaria und Spheniscide sind die beiden Muskelchen ziemlich transversal gerichtet, mehr linglich dagegen bei den Papageien (Taf. xxxi., Fig. 36 und xxxii., Fig. 34) [figures not reproduced here]. Bei Rhea sind diese Muskeln mit dem sie ganz bedeckenden UM. cerato-glossus verwachsen. Bei Passerinen habe ich sie nicht be- merkt ; bei Pelecanus und Sula, die eine sehr verkiimmerte Zunge haben, scheinen sie ganz zu fehlen. “5, M. HYPOGLOSSUS RECTUS. Hyoglosse droit. Cuvier ; Duvernoy. Hyoglossi interior s. rectus. Tiedemann, § 91, No. 3. Musculi linguales inferiores. Kutorga, p. 21. 42 THE MYOLOGY OF THE RAVEN. Zungenbeuger. Meckel, p. 408, No. 3. Hypoglossus rectus. Nitzsch. “Liegt wie der I. hypoglossus obliquus an der unteren Fliche der Zunge. Er entspringt nahe der Mittellinie etwas vorwirts vom M. H. obliquus und inserirt sich nahe dem Vorderende des Os entoglossum. “ Am deutlichsten entwickelt bei Papageien, fehlt er sehr vielen Végeln, und ist iiberhaupt nichts weiter als die vordere Verlin- gerung des MM. hypoglossus obliquus. Hiermit stimmt seine Innervation iiberein.” Norr.—These are all the lingual muscles alluded to by Professor Gadow in Bronn’s Thier-Reichs, and a moment’s comparison will show the corresponding ones as I found them in Corvus, and also such as are not found among Passerine birds. The following seem to be the correspondences to which I allude :— SHUFELDT. Gapow. Mylo-hyoideus = M. mylo-hyoideus anterior. Stylo-hyoideus = M. mylo-hyoideus posterior. Genio-hyoideus = M. genio-hyoideus. Cerato-hyoideus = M. cerato-hyoideus. Sterno-hyoideus = M. sterno-hyoideus, Depressor-glossus = M. hypoglossus obliquus (?). Cerato-glossus = M. cerato-glossus. What I take to be the Mf. hypoglossus obliquus of Gadow appears to be sufficiently evident in Corvus, and further than that genus I have not as yet looked into the matter. IV. THE MUSCLES OF THE AIR PASSAGES. As in the vast majority of birds, the rings and half- rings of the trachea of the Raven are completely ossified in the adult individual. This applies also, with equal truth, to the several parts of the superior larynx. These cricoid bones and the pair of arytenoid bones are so well known as to require no special description from me here. Their arrangement is very well shown in Fig. 10, where they are represented, in situ, double the size of life. Anteriorly, the upper larynx is composed of one shield- shaped osseous plate, the thyroid, which rests upon the upper side of the second basibranchial, in the fork of the greater cornua of the hyoid. This plate is also seen in Figs. 9 and 10. The bronchial half-rings, and those of the lower larynx, likewise ossify, but not quite so completely as do the tracheal rings above them. In the Raven we have devoted to the superior larynx two muscles— 28. The constrictor-glottidis. 29. The thyreo-arytenoideus. And to the lower larynx seven more, viz.— 30. The tracheo-lateralis. 34. The bronchialis posticus. 31. The broncho-trachealis posticus. 35. The bronchialis anticus. 32. The broncho-trachealis anticus. 36. The sterno-trachealis 33. The broncho-trachealis brevis. » Fic. 12.—-Tongue and salivary glands, Woodpecker. ¢ and &, the glands, the latter opened to show internal structure ; 4, the four turns of the cerato- tracheales around the trachea. (After Owen.) Fic. 13,—Front view of the lower larynx and bronchi of a Raven. g, part of the peripheral surface of the tympaniform membrane. are named in Fig. 14. (After Owen.) 5 Fic. 14.—Side view of the same parts that are shown in Fig. 18. «@ and f, diverging fasciculi of the ¢racheo-lateralis muscle ; the fasciculus @ is The muscles above THE MUSCLES OF THE AIR PASSAGES. 45 the broncho-trachealis posticus, and the fasciculus f is the broncho- trachealis anticus muscle ; b is a separate muscle, the broncho-trachealis brevis ; c, the bronchialis posticus ; ce, the bronchialis anticus ; d, the sterno-trachealis. (After Owen.) Fic. 15.—Lower larynx of a Parrot. a, tensor longus glottidis muscle. b, tensor brevis glottidis ; c, a narrow muscle passing from the tracheal to the bronchial half-rings. (After Owen.) Fic, 16.—Organ of hearing, Owl. f, the tensor tympani muscle ; ¢, the Eustachian tube ; 4’, the superior semicircular canal ; c, tympanum, and 6 is its periphery. (After Owen.) 28. The constrictor glottidis.—The inner margins of the rima glottidis in the Raven are formed by the mesial borders of the arytenoid bones. These latter articulate posteriorly with the middle segment of the cricoid, their antericr ends being free. Now the con- strictor glottidis muscle arises, on either side, from the superior and longitudinal line of the thyroid plate. From this origin it sweeps outwards, then upwards, and finally inwards in a gentle curve, to be inserted all along the inner margin of the corresponding arytenoid bone, and to the apex of the mid-cricoidal segment. When this pair of muscles firmly contract together, they efficiently close the rima, and draw the apices of the arytenoids to the middle line, and close against the upper surface of the thyroid plate. This action of the constrictor glottidis is opposed by the next muscle, the opener of the ruma. 29. The thyreo-arytenoideus (Figs. 10 and 18).—This pair of muscles arise, one on either side, from the entire outer margin of the thyroid plate, and the corresponding margin of the outer cricoid bone (Fig. 10). The fibres pass inwards, directly across the opening of the windpipe, to be inserted all along the outer margin of the arytenoid bone of the same side, and the cor- responding border of the central cricoid piece. It is evident that the contraction of this pair will tend to pull the arytenoid bones outwards, and thus open the rima glottidis. Fic. 17.—The under side of the hyoid arches of a Raven, with the superior larynx and upper part of the windpipe, in situ. Designed to show the attach- ment of the muscles of the parts ; the sterno-hyotdeus and the eleido- trachealis are pulled outwards by dissecting hooks. Life-size, by the author from his own dissections. : Fic. 18.—Superior view of the same parts, with lower muscles removed, but showing those attached to the upper side of the hyoid and superior larynx. The rima glottidis is represented as closed, with the arytenoids in contact. The elliptical aperture, which always remains in front, is closed by the upper surface of the thyroid plate beneath it. Y THE MUSCLES OF THE AIR PASSAGES. 47 “From the simplicity of the structure just described, from the situation of the superior larynx with relation to the rictus or gape of the bill, and from the absence of lips by which this might be partially or entirely closed, it is plain that it cannot be considered as influencing the voice, otherwise than by dividing or articulating the notes after they are formed by the lower larynx. The superior larynx presents, indeed, but few varieties in the different species of Birds ; and these relate chiefly to certain tubercles in its anterior, which vary in number, and do not exist at all in some species, as the Singing Birds; being chiefly present in those birds which have a rough, unmusical voice. In the Pelican, the Gigantic Crane, and most of the Rasores, a process extends backward in the cavity of the upper larynx from the middle of the posterior surface of the thyroid cartilage, and seems destined to give additional protection to the air-passages” (Owen). To examine the lower larynx, we must carefully free the trachea from the strong connective-tissue which sur- rounds it between the limbs of the furcula; then cut through the clavicular arch close to the hypocleidium, through the pectoral muscles, and down through the sternal body close to the carina. By means of this incision carefully open the chest. Next, after studying the relations of the beautiful pair of sterno-trachealis muscles, nip off the costal processes of the sternum, and free them from attached structures. Cut through the bronchi close to the lung, on either side, then lift out the lower Jarynx for examination. 30. The tracheo-lateralis—or either one of a pair of muscles of that name, for all seven muscles of the lower larynx of a Raven are in palrs—is formed by the union of the broncho-trachealis anticus and the broncho- trachealis posticus, about one and a half centimetres 48 THE MYOLOGY OF THE RAVEN. above the bifurcation of the bronchi, on the lateral aspect of the trachea. It ascends the side of the trachea for its entire length, as a narrow ribbon of muscle closely attached to the rings, until it arrives near the superior larynx, when it spreads out like a fan, and its faint and delicate fibres attach themselves to the side of the upper end of the windpipe. Contraction of this pair of muscles must shorten the trachea by closely ap- proximating the upper and lower borders of its rings. It also gives some support to this tube by acting as a brace to its sides. 31. The broncho-trachealis osticus is the hinder fasciculus formed by the forking of the last-named muscle. Its fibres pass downwards and backwards, and are inserted into the end of the third half-ring of the same side. 32. The broncho-trachealis anticus is the remaining limb of the bifurcation of the lower extremity of the tracheo-lateralis. Its fibres descend downwards and forwards to insert themselves upon the anterior extremity of the third half-ring of the corresponding side (Fig. 19). 33. The broncho-trachealis brevis is, upon either side, a strong, straight, subcylindrical bundle of muscular fibres which arise above just beneath the broncho-trachealis anticus muscle, descend rather obliquely across the larynx, to become inserted into the hinder end of the second bronchial half-ring (Fig. 14, 6). This muscular slip, as is shown in Fig. 19, is considerably larger than the broncho- trachealis posticus, which passes down, for the major part of its descent, alongside of it. 34, The bronchialis posticus is a chunky little spindle- formed muscle, situated below the other muscles just described. It arises by its superior apex from the Jatero-inferior margin of the ultimate tracheal ring, * THE MUSCLES OF THE AIR PASSAGES. 49 while its lower apex is inserted into the posterior extremity of the second half-ring. To do this it must be evident that it lies obliquely across the larynx. 35. The bronchialis anticus has much the same form as the last muscle, but is fully double its size. It is crossed at its origin by the broncho-trachealis anticus, which must be pulled to one side in order to examine it. We find that its superior apex arises from the last ring of the trachea, from which point the fibres pass obliquely forwards to become inserted by a lower apex into the rim of the arytenoid cartilage of the lower larynx, and the anterior extremities of the first and second half-rings. 36. Either sterno-trachealis is represented by a deli- cate little cord of muscular fibres, which arise on the side of the trachea beneath the hinder border of the broncho-trachealis anticus, and pass directly out- wards, a little downwards and _ backwards, across the cavity of the chest, to become inserted on the inner aspect of the corresponding costal process of the sternum, rather in advance of its centre. A delicate band of fascia spans the insertion of this muscle a few millimetres in front of its point of attachment. This is shown in Fig. 19. According to Owen, “this is the most constant of all the muscles affecting the lower larynx. It is reckoned by Savart as the sixth pair of vocal muscles, but not by Cuvier, since it is not directly attached to any part of the lower larynx, and exists in birds, as, ¢e.g., the Vulture and Ostrich, in which that larynx is not developed ” (Anat. Verts., vol. ii. p. 224). The infinite number of changes that the foregoing muscles can bring about in the form of an organ so con- stituted as the inferior larynx of the Raven is, can be more casily imagined than described. The principal E 50 THE MYOLOGY OF THE RAVEN. fact, however, to be kept before us is, that as the form and tension of its walls vary, the tympanic membrane AS, f i Se Mi sz Pe a wie i AE : Se s 8G £2 BR os § se BR 3 = 3 eA 5 8 , 33 Bf « 8 32 HA ‘ S RR ra ' . 33 ti 9 : » Be 35 ba FY s XRosy BAY « 3 & 2a ‘ Ea yy ' r SAAR GR of 22 Ewe FS =x 2 ay 2 A = e i rs AY ae Fic. 19.—Author’s sketch of his dissection of the musculature of the air passages of a Raven. Shown life-size upon lateral aspect. c.p., de- tached portion of the costal process of the sternum, of the right side, and turned about. which stretches across the mesial aspects of the bronchi, upon the vibrations of which the voice of the bird THE MUSCLES OF THE AIR PASSAGES. 51 depends, must also be brought to different degrees of tension in its different parts. Striking from the list the sterno-tracheales, all the muscles we have enumerated for the true larynx are tensors, as it is evident their contraction must stretch the tympanic membrane by lengthening the bronchi to which, as we have just said, it is attached. On the other hand, if the sterno- tracheales contract, they must stretch the windpipe, and thus shorten the bronchi, and relax the tympanic mem- brane. A glance at Fig. 13, where g is the tympanic membrane, will at once make these points clear. Professor Owen found that “in many of the Volitores there is a single pair of ‘ broncho-tracheales, and a single pair of short ventricose ‘ bronchiales.’ In Thamno- philus each sterno-trachealis bifurcates to send a small strip to the lower larynx, and the rest to the side of the trachea, as usual. In Furnaria the sterno-trachealis is inserted into the upper end of a long appendage to the upper bronchial half-ring. “The Parrot tribe have a single glottis bounded by a lateral pair of vibratile membranes ; each membrane connecting together, and occupying the interspace between, the last tracheal and first bronchial rings. These have each one margin concave, with the concavity towards each other, and are movably joined together at their fore and hind extremities. These half-rings expand, and stand out from the end of the trachea. A narrow muscle, ‘tensor longus glottidis,’ Fig. 105 [14], a, passes from the side of the trachea to the upper (tracheal) half-ring ; and, by raising it, makes tense the elliptical elastic membrane : a broader ‘ tensor brevis glottidis,’ 2b., b, passes from the lower rings of the trachea to the same half-ring, diverging to its extremities; a third narrow muscle passes from the tracheal to the bronchial half- E 2 52 THE MYOLOGY OF THE RAVEN. rings, 7b., c, and by approximating them, relaxes the membrane occupying the elliptical interspace. These membranes, projecting on each side into or below the termination of the air-tube, leave a narrow chink between them, through which the air passes to and from the lungs ; and when, in forcible expiration, the membranes are put into a sufficient state of tension, they vibrate, and the vocal air is driven along the trachea through the upper larynx, where some modifi- cation of sound may be made. The tongue of the Parrot is more fleshy than in most birds. These structures, concomitant with the single glottis and pair of vocal folds in the lower or true larynx, relate to the faculty, so remarkable in these singular birds, of imitat- ing human speech.” Other interesting variations in these structures are to be found in certain Cranes, in the peculiar Snipe Rhynchea, in certain Gallinaceous birds, and still more especially in many of the Anserine fowl: V. THE MUSCLES OF THE EYE AND EAR. Unber this head we will notice the following :— Those of the eye— 87. Orbicularis palpebrarum. - 43. Obliquus inferior. 38. Levator palpebre superioris. 44, Rectus superior. 39. Depressor palpebre inferioris. 45. Rectus inferior. 40. Quadratus nictitantis, 46. Rectus externus. 41. Pyramidalis nictitantis. 47. Rectus internus. 42. Obliquus superior. And the single one I propose to describe for the ear— the 48. Tensor tympani. To commence the dissection for a study of the muscles of the eye in the Raven, we should divide the skin down to the bone by a circular incision passing completely around it, a good distance back from the margins of the lids. Then dissect carefully, reflecting the integument as we approach these latter, equally all about them. This is best done by holding its free edge with the thumb and finger of the left hand, while we dexterously use a sharp scalpel held in the right, the skin being kept on the stretch. 37. The orbicularis palpebrarum is the first muscle we shall reveal during such a dissection, and its principal 54 THE MYOLOGY OF THE RAVEN. origin seems to be upon the lacrymal and maxillary bones (Fig. 22, 0.p.). Superiorly the circumscribing TCX, Fic. 20.—Superior aspect of head of Raven, with skin on right side dissected away, and the roof of the orbit removed, to show muscles of eye within. Life-size, by the author from his own dissections. 0b. énj., obliquus inferior ; 0b. sup., obliquus superior; r. iné., rectus internus ; 7. ex.,: rectus externus ; 7. swp., rectus superior. fibres become very indistinct, in which locality they are inserted directly into the ciliary margin. Below, they are attached to the lower free edge of the tarsal cartilage, THE MUSCLES OF THE EYE AND EAR. 55 and it is upon this lid that the action of the muscle is principally exerted, the eye being covered and closed, by its being drawn upwards over it. This muscle may now be divided at its principal origin; the integument dissected quite up to the free edges of the lids, where we carefully divide it all around, in order to remove these now unnecessary parts. Reflect- ing the dense tissue above the eye, we behold the organ tn situ. 38. Levator palpebre superioris.—The lower eyelid Fig. 21.—Mesial aspect of eye of Goose, to show muscular insertions (after Owen), with certain parts removed that appear in the original. op. m., stump of optic nerve: ¢, obliquus superior; d, rectus internus ; f, obliquus inferior ; b, rectus inferior ; c, rectus externus ; A, pyramidalis ; h’, its tendon ; g, quadratus ; a, rectus superior. is the one which principally closes the eye in the Raven, consequently we find the present muscle but feebly developed, while, on the other hand, the next to be described is quite strongly so. The levator palpebree superioris arises along a longitudinal line found at about the middle of the roof of the orbit within. The faint and delicate fibres pass directly outwards to find insertion in the ciliary margin of the upper lid, being best seen rather on the side towards the outer canthus. As in the 56 THE MYOLOGY OF THE RAVEN. Mammalia, the function of this muscle is to raise the superior eye-lid. 39. The depressor palpebre inferioris, as has already been stated, is easily found. Its fibres are attached along the lower margin of the interorbital vacuity. From this line (Fig. 22) they pass outwards beneath the eyeball, to become inserted into the lower lid, where they ft v yr : Fic, 22.—Right lateral aspect of skull of Raven, to show exact origins of the principal muscles of the eye, and the tensor tympani. _Life-size, by the author. Lettering as in Fig. 20, with ¢.t., tensor tympani; 0.p., orbicularis palpebrarum ; 7, lacrymal bone; J. pal. sup., levator pal, pebra superioris ; d. pal. inf., depressor palpebre inferioris ; 7. inj., rectus inferior, antagonize to a certain extent the orbicularis palpe- brarum, as by their contraction this integumental veil to the organ of sight, the lower lid, is withdrawn. Owen tells us that this muscle is also found in the Crocodile, and I dare say in other Sauropsida. In the Raven it is the only lid of the three which is reinforced by a THE MUSCLES OF THE EYE AND EAR. 57 cartilaginous plate, here found between the conjunctival membrane and the ligamentous layer. It is of interest to know that in the Strigide and Caprimulgi the eyes are closed principally through the depression of the upper lids. In common with most other birds, the Raven possesses a well-developed membrana nictitans, which is here of a pearly white colour, and consequently opaque. As it closes, it passes obliquely across the eyeball, from its resting-place in the supero-internal corner, to the one opposite, a movement effected by two special muscles, the next to be described (Fig. 21). 40. The quadratus nictitantis finds its origin upon the sclerotic at the upper part of the ball, behind. From this point the fibres converge as they pass towards the optic nerve, and are inserted in an aponcurosis which sheathes the latter above. It is evident that in this course the fibres of the quadratus pass downwards, inwards, and backwards, interfering in no way with the action of the other muscles, have no fixed bony insertion, and do not stand in the way of the passage of the rays of light. 41. The pyramidalis metitantis, the remaining muscle acting upon the membrana nictitans, occurs in the Raven precisely as we find it in the Goose, and it has been so well described by Owen for that bird, that I quote his words. Hesaysthe “ pyramidalis nictitantis (Fig. 21, h, of the present work) arises from the lower and nasal side of the eyeball : its fibres converge towards the upper part of the optic nerve, and terminate in a small round tendon which glides through the pulley at the free margin of the quadratus ; thus, winding over the nerve, it passes down to be inserted into the lower part of the margin of the third eyelid. By the simultaneous action of the two muscles, that nictitating lid is drawn outward and 58 THE MYOLOGY OF THE RAVEN. obliquely downward over the fore-part of the eyeball The tendon of the pyramidalis gains the due direction for that action by winding round the optic nerve, and it is restrained from pressing upon the nerve by the counteracting force of the quadratus, which thus augments the power of the antagonist muscle, while it obviates any inconvenience from pressure on the optic nerve, which its peculiar disposition in relation to that part would otherwise occasion. The nictitating mem- brane returns on the relaxation of its muscles, by virtue of its own elasticity, to the inner corner of the orbit, where it lies folded when not in use” (Anat. of Verts., vol. ii. p. 143). 42. Obliquus superior.—As in the Mammalia, the movements of the eyeball depend upon the action of two oblique muscles and four recti muscles (Fig. 22). The oblique muscles arise close together at the inner and superior angle of the pars plana, their exact origins being shown in the figure. Between them passes the olfactory nerve. The origin of the superior oblique is situated the more posteriorly, and rather lower than that of the obliquus inferior. Its diverging fibres pass backwards and outwards, forming a pretty, fan-shaped little muscle, to spread over the upper side of the eye- ball, their extremities being overlapped by the rectus superior. In none of these eye-muscles proper do the terminations of the fibres of insertion reach so far as the osseous circlet formed of the sclerotal plates; and it is evident, further, that, owing to the greatly confined condition of the eyeball, the necessity for a ligamentous pulley to assist the action of the present muscle is obviated. 43. The obliquus inferior muscle arises, as we have just stated, close to the last described one (Figs. 20, 22, THE MUSCLES OF THE EYE AND EAR. 59 ob. nf.). Its fibres pass in exactly the same direction, differing only in their downward, rather than the upward inclination, in order to become inserted in the sclerotic of the inferior aspect of the eyeball, where they are overlapped by the inferior rectus muscle. ' The action of these two oblique muscles is too simple to require a detailed description here. They are the direct antagonists to each other, and are principally con- cerned in movements of torsion of the eye. 44. Rectus superior—the several origins of the recti muscles circumscribe the optic foramen, just within its free border. The rectus superior and internus surround its upper half, while the rectus inferior and externus arise below. The rectus externus arises by two distinct heads, between which the sixth nerve passes out of the brain-case through a small circular foramen which appears to be constant in the Raven (Fig. 22). The fibres of the rectus superior diverge as they pass forwards, upwards, and outwards, the innermost ones overlapping those of the obliquus superior at right angles. They are inserted into the sclerotic just within the margin of the bony circle of the eye (Fig. 20). 45. The rectus inferior muscle is to the rectus superior exactly what the obliquus inferior muscle is to the obliquus superior. Its fibres spreading out like a fan, as they pass from their origin, are inserted on the lower aspect of the eyeball, in the same manner as the fibres of the rectus superior are inserted upon its upper side. 46. The rectus externus seems to be the shortest of all the recti muscles; and, as I have already remarked, it arises by two heads, disposed as shown in Fig. 22. It also is fan-shaped, and finds insertion, in a way similar to the two foregoing muscles, on the external, or what is really the posterior side, of a Raven’s eye. 60 THE MYOLOGY OF THE RAVEN. 47. The rectus internus, after leaving its origin, spreads out over the mesial aspect of the eyeball, clearing by a well-devised arrangement the quadratus and pyramidalis, though in intimate relation with the former : it is finally inserted, in a manner common with the others of the group, upon the sclerotic, or the anterior aspect of the i ®@ 2 > v ay 2 ” * iA ws NG ° 2 oss tate 4 °Plica Se 2erve, Under side of ey?’ Fic. 23.—The back of the right eye of a Raven, x 23, and showing the cut stumps of the rect and obligui muscles, which, however, are drawn away from the centre to show their proper insertions. The guadratus nictitantis is represented inastate of semi-contraction, when it lifts the tendon of the pyramidalis nictitantis off of the optic nerve. Could the front of this eye now be seen, the membrana nictitans would be found about three-quarters drawn obliquely across the eye. The pyra- midalis is here contracting then, and it is evident that both its force and function are augmented by this action of the quadratus. The curious elliptical osseous plate surrounding the optic nerve, is also shown in the figure, and I have found it in every Raven’s eye that I have dissected. eye, or what would be the internal side in the Mammalia. Were it to act alone, the other muscles remaining passive, it would so pull the eyeball as to direct the line of vision to the front. By way of recapitulation, then, of the nomenclature of THE MUSCLES OF THE EYE AND EAR. 61 the eye and its appendages in a Raven, we find that its movements are effected by eleven muscles. The or- bicularis palpebrarum by its contraction closes the integumental lids. It is antagonized by a feeble levator palpebre suwperioris in the upper lid, anda much better developed depressor palpebre inferioris in the lower lid, which latter is the one which really “closes the eye.” The third eyelid, or membrana nictitans (nictito, I wink), is governed in its action by the two muscles, the quadratus and the pyramidalis, but their operation is best seen by a study of Fig. 23. When these muscles cease to act, the nictitating membrane contracts by virtue of its own elasticity, and again becomes hidden within the recess of the inner canthus, above the com- missural point, of the true lids. The remaining six muscles are devoted to the move- ments of the eyeball itself. Any of the recti, when acting, antagonize the muscle inserted diametrically opposite it; the two obliques similarly oppose each other, and through the varied traction of the group the line of vision is directed to meet the will of the bird. Owing to the close contact of the bony walls of its chamber, the greater simplicity of the obliqu, and, finally, the shortness of all these muscles, the mechanism involving the movements of the eyeball is not nearly so complicated a one in the bird, as we find it to be in any Mammalian form. VI. THE MUSCULATURE OF THE EAR. Upon one of the foregoing pages I have already described the circwmconcha muscle, which I believe, from my dissections, to be a constant one in the Raven. By its contraction it evidently acts as a “laxator” to the tympanum. Careful search in a large number of ears of this bird, however, fails to reveal to me any such “tensor” as described by Professor Owen. I do find, though, the following muscle :— 48. Tensor tympani.—lf we carefully dissect the integument about the aural orifice in an old bird of this species, we find a small fasciculus of muscular fibres that arise from the inner end of the quadrato-jugal bone, and the contiguous surface of the quadrate. These pass beneath the integumental duplicature in the shallow meatus, to be lost upon the inner surface of the tympa- num. Now, as the drum is braced in the ear-passage by at least two or three ligamentous bonds, more espe- cially by a strong one above, it is very evident that, by the contraction of such a muscle as I here describe, the ear-drum would be put upon the stretch, and its tense condition duly effected (Fig. 22, #.t.). In describing the tensor tympani in an Owl (Fig. 16, f-), Professor Owen says: “ It arises from a depression THE MUSCULATURE OF THE EAR. 63 in the basisphenoid, enters the tympanic cavity above the beginning of the Eustachian tube, and, by its inser- tion into and action upon the malleus, tends to push the membrane outward; it is counteracted by two small cords extended to the inner walls of the tympanum : but the muscular character of them is doubtful, and the ear-drum resumes its normal state when the tensor ceases to act” (Anat. of Verts., vol. ii. p. 135). Further investigations in this direction will be very interesting and quite important. The general text- books of Claus, Gegenbaur, Jeffrey Bell, Huxley, and many others at my command, are silent upon this point.! 1 Since writing the above I find the following from Professor Hans Gadow (loc. cit., Bronn’s Klassen, vi. Band, pp. 442-445) upon the musculature of the eyes and the eyelids in Aves :— “Dre AvGENMUSKELN (Taf. xliii. and iv.). [Figures not reproduced here. ] “Die 8 Muskeln des Augapfels und des dritten Augenlides ent- wickeln sich embryologisch aus den Resten der vorderen Kopfsomiten (vgl. s. 297). “Der Augapfel selbst wird von sechs Muskeln bewegt, namlich von vier ‘ geraden’ und zwei ‘schiefen’ Muskeln. “1. M. rectus superior s. attollens entspringt fleischig von dem oberen Rande des Foramen opticum und heftet sich mit breiter, aber kurzer Aponeurose an den oberen Rand des Uebergangstheiles des Augapfels. Ueber den Urspringstheil des Muskels lauft der R.I. des WV. trigeminus und der WN. trochlearis. Innervation durch den N. oculomotorius und zwar durch einen kurzen Ast desselben, der sogleich noch seinem Hintritt in die Orbita zur unteren Fliche des Muskels geht. “2. M. rectus inferior s. deprimens, entspringt fleischig von der unteren und hinteren Umgebung des Foramen opticum und inserirt sich mit ziemlich breiter Ausdehnung an dem unteren Rande des Augapfels. Er wird ebenfalls vom MW. oculomotorius innervirt, und zwar durch ein Biischel feiner Aeste, die den Hauptstamm nach Abgabe des Ramus ciliaris verlassen. 64 THE MYOLOGY OF THE RAVEN. “3. M. rectus internus s. medialis adduceus, entspringt nach vorn vom Austritt des Scbnerven und inserirt sich am Innenrande des Augapfels. Er wird medianwirts von der Harder’schen Driise und vom R. I. WV. trigemini, nach oben hin vom JM. obliqguus superior be- deckt. Innervirt durch einen Zweig des V. oculomotorius. “4. M. rectus externus s. lateralis s. abducens, entspringt seit- lich und hinten neben dem JM. rectus superior und inserirt sich am hinteren Seitenrande des Augapfels. Seitlich von ihm verlauft der R. II. trigemini. Innervirt durch einen Ast des J. abducens. “5. M. obliquus superior, entspringtweit nach vorn, von der Eth- moidalwand ; iiber seinen Ursprung zieht der WM. olfactorius hin, dicht unter ihn verliuft der R. I. trigemini, Der Muskel lauft dann quer iiber den Insertionstheil des WZ. rectus internus und heftet sich sehr breit dicht nach innen, und theilweise unter der Insertion des M. rectus superior an den Augapfel. Er wird vom WM. trochlearis innervirt. “6. UW. obliquus inferior, ein langer diinner, bandartiger Muskel, der seitlich vom M. rectus inferior entspringt und sich medianwiarts neben demselben inserirt. Nach unten und aussen liuft iiber seinem Ursprungstheil der R. superior des 4. carotico-cephalicus (s. L. 384) hinweg. Er wird vom letzten Zweige des WV. oculomotorius in- nervirt. “« Ausser diesen sechs Muskeln des Augapfels besitzen die Vogel und meisten Reptilien noch zwei, welche zur Bewegung des dritten Augenlides dienen. “7. M. quadratus membr. nictitantis, entspringt flach und breit unter und zwischen den Insertionen des M. rectus internus, M. obliquus superior, und M. rectus superior. Er ist von trapezoider Gestalt, indem er an der Basis am breitesten ist und nach dem Sehnerven hin schmaler wird: letzterer Rand bildet eine aponeur, otische Schleife fiir die Sehne des /. pyramidalis. Der M. quadratus wird vom WV. abduceus innervirt. “8, IM. pyramidalis membr. nictitantis. Entspringt von der unteren inneren nasalen Wand des Augapfels, von den Insertionstheilen des M. obliquus inferior und M. rectus inferior bedeckt. Der Muskel spitzt sich bald zu, geht median und dorsal vom JN. opticus in eine runde Sehne iiber, welche dorsalwiirts vom Sehnerven durch die Schleife des I. guadratus lauft, dann wieder abwiirts geht und zwischen den Insertionen des Jf. rectus externus und des M. rectus inferior auf die Vorderfliche des Augapfels tritt, wo die Sehne in THE MUSCULATURE OF THE EAR. 65 die durchsichtige Nickhaut iibergeht. Innervation durch den J. abduceus. “Dre AUGENLIDER [MusKELy]. “Die Bewegang der Augenlider wird durch mehrere Muskeln bewirkt. Der I. obicularis, Sphincter, oder Schliessmuskel lauft kreisformig unter der Aussenhaut der Lider um die Lidspalte herum und heftet sich an den Lidknorpel an. “Der M. levator palpebre entspringt vom oberen Dache der Augen- hohle und heftet sich an den dusseren Winkel des oberen Lides. “Der M. depressor palpebre inferioris ist bedeutend stirker als der vorige, und entspringt in der Tiefe der Augenhthle. Bei Rhea bildet der Muskel ein langes, breites Band, welches theilweise vom Alisphenoid, und lateral ventral neben dem Ursprung des Jf, rectus externus entspringt. Es inserirt sich hauptsichlich am binteren, unteren Rande des Lidknorpels. “Bei den meisten Vogeln (Hiihner, Schwimm-, Singvégel) ge- scnieht das Schliessen des Auges durch Heraufziehen des unteren Lides, und das obere Lid bewegt sich sehr wenig, oder gar nicht, wie bei den Reptilien. Selten senkt sich auch das obere Lid etwas durch Contraction des M. orbicularis, wihrend das untere sich hebt : Eulen, Caprimulgus, Tauben. Nur in wenigen Fallen, wie beim Strauss und bei den Papageien besitzt das obere Lid gréssere Be- weglichkeit als das untere, wie bei den Singethieren. Ueberhaupt ist der Grad der Ausbildung der drei Lidmuskeln ein sehr wech- selnder. ‘“‘ Merrem entdeckte beim Adler noch einen ‘ Augenbrauenmuskel.’ Er ist sehr diinn, entspringt von einer kleinen Hervorragung des oberen Randes der Augenhéhle und inserirt sich an dem den Tagraubvégeln eigenthiimlichen Augenbrauenknochen, den er in die Héhe zu heben scheint. “Die Innervation der Lidmuskeln geschieht durch den WV. oculo- motorius und durch den R. I. des Trigeminus.” VII. THE MUSCLES OF THE UPPER EXTREMITY. In describing the muscles of Vertebrates, anatomists usually, after completing their descriptions of the muscles of the head, take up next in order the musculature of the neck and trunk. I have found it to be the case with birds, however, that by far the most convenient method of procedure proves to be to take up first our studies and dissections of the muscles of the upper extremity, and, having completed these, turn our attention next to the muscles of the lower extremity, which are to be similarly dealt with, and thoroughly disposed of, before any of the muscles of the trunk proper have been examined. This course gives us the opportunity of clearing away the very large pectoral muscles of the bird, the heavy muscles of the thigh, and, finally, removing the limbs altogether. We then have nothing left but the much lighter neck and trunk to deal with, which are easier handled, and their muscles worked out with far greater pleasure and satisfaction. To expose the muscles of the upper extremity we make a circular incision through the integuments at the root of the neck. This is met by a linear incision made on the anterior aspect of the body following the keel of THE MUSCLES OF THE UPPER EXTREMITY. 67 the sternum, and following midway between the limbs of the furcula. Posteriorly, this linear division of the pectoral integuments is carried well beyond the hinder sternal margin. Next, make a similar median incision upon the dorsal aspect of the body, meeting the circular incision at the root of the neck, and carried posteriorly as far back as the anterior border of the pelvis. Dissect away the skin from the left side of the body, and from the left upper extremity, leaving the right side covered, in order to keep the muscles moist, and intact for com- parison, if we find it necessary, with those of the side we have under examination. Divide the dermal muscles as we come across them, during our operation of removing the integuments, at their middles, allowing the proximal portions to remain, in order that their relations may be studied. In removing the integumental fold of the patagium carefully study the mechanism of the tendons of the patagii muscles, as well as the muscles themselves. We also find in this fold other small muscular tendons, which will hereafter be described. The relations of the pos- terior patagial fold should also be carefully studied, as well as the dermal muscles that lie within it. Great care is necessary when you come to remove the skin covering the pinion, as it is intimately attached to the tissues overlying the muscles and tendons beneath it, in several places, which are liable to be injured by the scalpel if the removal is too hastily undertaken, or the skin simply torn off. THE PECTORAL MUSCLES. 49, The pectoralis major. 51. The pectoralis tertius. 50. The pectoralis secundus. This group of muscles is second to none in importance as compared with any other in the entire muscular F2 (e ee b way bu o1) sdortg (Pe2% $u07) sdooul L “stTereuny: 098109 ‘'Y"9 sroyyue ayy Aq ‘ozis-otT “Woers|} UMOYs SepOSNT LeT|}O PUL O[SULUT Sy Jo Woasur pue UPSILO yowKe OY} TIT ‘qeavy @ JO YUNI} 944 JO UOpTOHS HOPG ~ Y “gngsouod qhivaurTued, S ‘gnurtad sragmF L iS oY JO MATA [BIE}2] IPSIY— “FS “OL THE MUSCLES OF THE UPPER EXTREMITY. 69 system of any one of all those birds possessed of the power of flight. 49. The pectoralis major is by far the largest muscle 1 Firbringer and Gadow divide the pectoralis major muscle into three parts, viz. the pars thoracica, the pars propatagiulis, and the pars abdominalis. Omitting the descriptive part, I present the synonymy of these divisions as recorded by Gadow in Bronn’s Klassen des Thier-Reichs, (vi. Band, pp. 241, 242), which is as follows :— “73. M. PECTORALIS. “TY. Pars thoracica. Depressor ale. FBorelli. Grand pectoral. Vicq d’Azyr, 1772, p. 623, No. 1. 53 Cuvier. 7 Gervais et Alix, p. 24; Alix, pp. 399-401. Pectoralis major. Merrem, p. 152; Wiedemann, p. 82. Grosser Brustmuskel. Tiedemann, § 249. 3 55 Meckel, p. 315, No. 8; Schopss, p. 108, No. 15; Prechtl, § 35. 55 5 Reid, p. 140 ; Rolleston, p. 4. . 3 $5 De Man, p. 109 ; Watson, p. 80. Pectoralis major et minor. Selenka, p. 121, No. 46 u. 47. Pectoralis. Fiirbringer, Morpholog. Jahrb, v., Monographie ; Carlsson, p. 26. “TIL. Pars propatagialis (Fiirbringer). Tensor patagts membran. ant. ale, Selenka, No. 48 und 49 (partim). Sehne vom Pectoralis major zum Tensor brevis patag. ant. De Man, p. 110. Verstiirkendes Sehnenbiindel vom Pect. major. De Man, p. 111. Tensor membrane anterioris ale, Theil a und 6. Heusinger, p. 185, No. 19. Langer und Kurzer Muskel der vorderen Fliigelfalte. Schépps, No. 2 und 3 (partim). Spanner das Windfangs. Prechtl, § 69 (partim). “TIL Pars abdominalis (Fiirbringer). Subcutaneus abdominalis. Wiedemann ; Tiedemann, § 100, No. 5. 5 55 Watson, p. 55. 5 thoracis, Tiedemann, § 100, No. 4; Prechtl, § 71. 70 THE MYOLOGY OF THE RAVEN. of the system in a Raven, both as regards weight and general bulk. It arises from the posterior moiety of the anterior surface of the sternal body, to the extent shown in Fig. 25 ; from the entire marginal third of the corre- sponding aspect of the keel, as seen in Fig. 24; and finally from the entire outer side of the corresponding clavicular limb of the furcula, as indicated in Fig. 8. The fibres from this extensive origin converge, with but little tendency to overlap as we find them in man, toward the proximal third of the humerus of the same side, into which they are inserted by a broad tendon occupying the entire surface of the palmar aspect of the pectoral crest. The posterior surface of the pectoralis major is far more tendinous in structure than its anterior, and as it passes over the shoulder-joint this tendinous portion becomes intimately blended with the long head of the biceps, while near this point it also receives the insertion of the dermo-humeralis (No. 12), the fan-like tendon of the latter blending with the broad tendon of the pectoralis. In the sternal region the pectoralis major completely covers the other two pectoral muscles which arise from the sternal body. This muscle when contracting depresses the humerus with great force, and consequently the wing of the bird, and so forms the chief agent of flight. In describing the pectoralis major for birds in general, Sir Richard Owen says that “This muscle is very long Ohne Namen erwahnt. Schdépss, p. 112. Dermo-humeralis. Owen, p. 24. Panniculus carnosis (second portion). Reid, p. 139. Muscle des parures. Gervais et Alix; Alix, p. 401. eT, * Watson, p. 81.” [See the present writer's description of the dermo-humeralis in the present connection. ] THE MUSCLES OF THE UPPER EXTREMITY. 71 and wide in the Natatores generally, but in the Penguin, its origin is limited to the external margin of the subjacent pectoral muscle, which is here remarkably developed. The great pectoral is very long, but not very thick in the Rasores. In the Herons it is shorter, but much stronger and thicker. Its size is most remarkable in the Humming-birds, Swallows, and Fic. 25.—Anterior aspect of the sternum of a Raven, designed to show the areas of origin of the pectoral group of muscles. The subclavius lies beneath the p. tertius. Life-size, from the specimen. diurnal birds of prey, where it is attached to almost the whole outer surface of the sternum, and its crest, and has an extended insertion. In the Ostrich its origin is limited to the anterior and external eighth part of the sternum, and it is inserted by a feeble tendon into the commencement of the pectoral crest of the humerus, to which it gives a strong rotary motion forwards. In the Apteryx the pectoralis mayor 72 THE MYOLOGY OF THE RAVEN. is represented by two thin triangular layers of the muscular fibres attached to the under and lateral part of the sternum, and converging to be inserted into the proximal third of the minute humerus” (Anat. of Verts., vol. ii., p. 96). 50. The pectoralis secundus' (Figs. 24, 25, 26, 29, and 30) arises from the remainder of the keel of the sternum not appropriated by the pectoralis major, as 1 This is the M. supRacoRacorpEus of Professor Hans Gadow (Bronn’s Klassen, vi. Band, p. 246), who has given a very full description of it, together with the following synonymy, which I republish below :— “74, M. SUPRACORACOIDEUS. Pectoral moyen. Vicq d’Azyr, 1772, p. 624; Cuvier. a i Gervais et Alix, p. 24. Mittlerer Brustmuskel. Merrem, p. 152, No. 2. Pectoralis minor. Reid, p. 141. 3 38 Nitzsch-Giebel (Upupa, Coracias, Papageien). Pectoralis minor s. medius. Wiedemann, p. 83. rr oe SR Ff Tiedemann, § 250. 3 iF 3 Heusinger, § 183. Zweiter Brustmuskel. Meckel, System, p. 817, No. 11. (Pectoralis secwndus). Haughton (Emu, Rhea). 5 5 Forbes (Tubinares) ; Weldon (Pheenicopterus et Leptoptilus). Deltoides maximus. Schiépss, p. 124, No. 21. Kleiner Brustmuskel (Umroller des Oberarms). Prechtl, § 40. Pectoralis medius s. secundus. Owen, Apteryx, p. 289. Subclavius. Rolleston, p. 624. » Selenka, Bronn, p. 118, No. 44; und Archiv Néer- land., 1870, p. 48 ff. 3 De Man, p. 109. Pectoralis tertius. Jéger Literatur, No. 80. Pectoralis major (partim ?). Riidinger, p. 89. Sus-épinewx + accessoires du sus épineux. Alix, p. 396-399. Pectoralis medius. Watson, p. 82. Supracoracoideus. Fiirbringer, Morphol. Jahrb., v. und dJfono graphie ; Carlsson, p. 25.” THE MUSCLES OF THE UPPER EXTREMITY. 73 well as from a contiguous strip of the anterior surface of the sternal body. It also finds origin from a tendi- nous expansion stretching between the corresponding coracoid and tbe os furcula, and from the anterior sternal extremity of the lower third of the coracoid itself (Fig. 24). From these several points of origin the muscular fibres of the second pectoral rapidly contract as they converge, to pass upward and round the coracoid to its posterior aspect. As they approach the shoulder-joint the carneous fibres become tendinous to form a rounded and strong cord. This passes through the canal formed by the scapula, coracoid, and clavicle, and immediately upon emerging above it is directed outwards and downwards, to be inserted as a strong and somewhat flattened tendon just anterior to the radial crest of the humerus, on the same side but nearer the humeral head than the pectoralis major. It must not be understood from what I have just said that the fibres of this muscle pass directly to their humeral tendon, for more strictly speaking they gradually merge, as they pass in that direction, into a tendinous sheet which traverses the muscle longitudinally, and appears as a tendinous line upon its anterior aspect. Through the leverage gained by the tendon of this muscle passing through the osseous canal formed by the bones of the. shoulder-girdle, it acts as a levator of the wing, the humerus being raised by its contraction. And this mechanism is very prettily effected in spite of the fact that the chief weight of this muscle is thrown in favour of depressing the centre of gravity of the bird’s body, a very essential point to be attained, in facta positive requirement during flight. Owen says, “In the Penguins, Guillemots, and Gulls, this muscle is almost the largest of the three, occupying 74 THE MYOLOGY OF THE RAVEN. the whole length of the sternum. It is remarkable for the length and strength of its tendon, which is inserted so as to draw forwards the humerus with great force. It is proportionately the smallest in the Raptores; and is very small and slender in the Struthious birds. “We have already alluded to the use which the Penguin makes of its diminutive anterior extremities as water-wings, or fins; to raise these after making the down-stroke obviously requires a greater effort in water than a bird of flight makes in raising its wings in air ; hence the necessity for a stronger development of the second pectoral muscle in this and other diving birds, in all of which the wings are the chief organs of locomotion, in that action, and consequently require as powerful a development of the pectoral muscles as the generality of birds of flight” (loc. cit., p. 97). Mr. W. A. Forbes says that the pectoralis secundus “in the Albatrosses is unusually short, and broken up into four quite separate parts, which unite before passing the shoulder-pulley. In the other Petrels, the muscle is much more homogeneous, and only separable by dissection into its various component parts” (Coll. Memoirs, p. 389). 51. The pectoralis tertius! is the smallest of the 1 Gadow (ioc. cit., p. 252) prefaces his description of this muscle by the following synonymy, he having proposed the name of the m. coraco-brachialis posterior for the pectoralis tertius : — “76. M. CoRACO-BRACHIALIS POSTERIOR. Le petit pectoral. Vicq d’Azyr, 1772, p. 625 ; Cuvier. Kleiner Brustmuskel. Merrem, p. 152, No. 3. Pectoralis minimus. Wiedemann, p. 83. 45 af Tiedemann, § 251. i 49 Heusinger, p. 183. s 5 Prechtl, § 37. Coracobrachialis inferior. Meckel, System, p. 319, No. 19. THE MUSCLES OF THE UPPER EXTREMITY. 75 pectoral group of muscles, and is found to the outer side of the one last described. As with the first two, its fibres arise fleshy, and in its case, from an area occupy- ing the-anterior half (in length) of the outer moiety (in width) of the pectoral aspect of the body of the sternum, including the broad costal process where it is attached to the fascia of the swbclavius muscle which lies beneath it. It also arises from the outer lower third of the corresponding coracoid process, which latter area lies in close juxtaposition with the somewhat similar origin of the second pectoral (Figs. 24 and 25). From these two origins the fibres of the muscle converge as they ascend upwards, pass to the outer side of the coracoid bone, and as they approach the humerus they become Pectoralis tertius. Schépss, p. 113, No. 16. Coraco-brachialis s. Pectoralis tertius s. minor. Riidinger, p. 80. Coraco-brachialis, Reid, p. 141; Gervais et Alix, p. 23 ; Alix, p. 393. Subclavius. Retzius. Pectoralis minor s. tertius. Owen, Apteryx, p. 289. Coraco-brachialis longus. Selenka, p. 114, No. 40; De Man, p- 106; Carlsson, p. 26. Coraco-brachialis internus. Fiirbringer, Morph. Jahrb. v. Pectoralis minor. Watson, p. 83. Coracobrachialis posterior s. internus. Fiirbringer, Monographie.” Valuable observations are passed upon this muscle by the writer just quoted in the same connection, and he, after dwelling upon its anatomy in a number cf bird-groups, declares that, ‘‘ Er entspricht nicht dem J. coraco-brachialis des Menschen, der vom Proc. cora- coideus zum Schafte des Humerus geht. Besser zu vergleichen ist er einem zweiten Jf. coraco-brachialis, der bei vielen Siugethieren sich am Tuberc. int. humeri besfestigt und bei den Monotremen, die ein Sauropsiden ahnliches Coracoid besitzen, sehr stark und vogelibnlich entwickelt ist. Dass er nicht als ein Pectoralis minor, soudern als Corac. brachial. aufzufassen ist, hat Selenka (Literatur, No. 121) ausgefiihrt. Bei den Amphibien und Rep- tilien ist er in dem ebenfalls als Coraco-brachialis beschriebenen Muskel zu erkennen”’ (oc. cit., p. 253). 76 THE MYOLOGY OF THE RAVEN. tendinous, and finally form a strong, somewhat flattened tendon, which is inserted into the ulnar crest of the humerus, on the proximal margin of the pneumatic fossa, at about its middle point. This muscle assists the pectoralis secundus in elevating the humerus, when it is brought into action by the contraction of its fibres. Professor Owen seems to have found quite a different origin and insertion in other birds for this muscle, as he says, ‘the third pectoral muscle, which is in general the smallest of the three, arises from the anterior part of the sternum at the angle between the body and the keel, and also by a more extended origin, from the posterior moiety of the inferior surface of the coracoid and the coraco-clavicular membrane; it is directed forward, rising to pass through the scapulo-coracoid trochlea ; its tendon glides through a sheath, attached to the capsule of the shoulder-joint, and in some birds to the os humero-scapulare ; and is inserted into the radial tuberosity of the humerus, which it helps to raise. It is proportionally large in the Penguins and Gulls, but attains its greatest development in the Gallinaccous order ” (loc. cit., p. 97). Mr. Forbes, who investigated the myology of the Tubinares, collected during the voyage of the Chal- lenger, found the pectorales tertvws in them to be “in the form of a broad, thin band, more or less parallel with the coracoid, occupying the superior half of the broad space between that bone and the furcula, its fibres arising chiefly from the strong membrane between these bones, sometimes with additions from the anterior mar- gin of the coracoid, or from the body of the sternum close to the middle line” (Coll. Memoirs, p. 390). Before closing my account of this group of muscles, I THE MUSCLES OF THE UPPER EXTREMITY. 77 must call attention to one other fact in regard to this third pectoral, and that is this: after having dissected HP a: = s TNT { uf € Fic. 26.—Superficial muscles, anterior aspect, of the upper extremity, as far as the elbow, of a Raven. Drawn life-size by the author from his own dissections. Al] of these muscles are in their normal positions, but the size of the figure did not admit of showing the insertions of the tensor patagii slips, though their proximal moieties are shown in their proper positions. away the pectoralis major, in nearly all specimens, the outer margins of the second and third pectorals appear 78 THE MYOLOGY OF THE RAVEN. as though they were continuous, or a prolongation of the same oblique line ; this is indicated by the shading across the belly of the pectoralis tertius in Fig. 27. In very muscular subjects, however, this muscle does not terminate at this line, but very delicate fibres pass beneath the fascia so as to cover an area of origin as indicated for the pectoralis tertius in Figs. 24 and 25, where its full extent or limit is shown for a very power- fully-developed, old muscular male bird.} DORSAL MUSCLES OF THE UPPER EXTREMITY. Several of the muscles to be described under this head are generally spoken of by anthropotomists as ‘“ muscles 1 In certain birds there is a small muscle in the axillary region, which I have failed to discover in a Raven, and its place seems to be insome ways replaced by the dermo-ulnaris muscle. Mr. Garrod describes it in the following words for Chauna; he says the ‘“ Expansor secundariorum is the name which it is my habit to employ for a very small and peculiar triangular muscle arising from the quills of the last few (generally two or three) secondary remiges at the elbow. Its remarkably long and slender tendon, which frequently traverses a fibrous pulley on the axillary margin of the teres muscle, runs up the arm side by side with the axillary vessels and nerves to be inserted in the thorax, into the middle of a tendon which runs from the inner side of the middle of the scapular element of the scapulo-coracoid articulation to near the middle of the thoracic border of the sterno-coracoid articulation, at right angles to it when the fore-limb is extended. This arrange- ment being found very well differentiated in the Storks may, for the sake of convenience, be termed Ciconine” (see Collected Scientific Memoirs, 1881, p. 323, and plate showing this muscle in Chauna, No 16, where it is marked e.s.; or the same plate in the P.ZS. of 1876, No. xiv.). The author has as yet never examined any of our American Herodiones for this muscle. Since writing this footnote, nearly three years ago, my oppor- THE MUSCLES OF THE UPPER EXTREMITY. 79 of the back,” but, as I have already decided above, it is my intention to consider all those muscles which find tunities to examine into the literature of this subject have much improved, and (in Bronn’s Klassen des Thier-Reichs, vi. Band, p- 258) I find a very excellent description of this muscle by Professor Gadow, too long, I regret to say, to reproduce here. This will not apply, however, to the synonymy which he there presents, and which reads as follows :— “78, M. METAPATAGIALIS. Une portion du grand dorsal. Vicq d’Azyr, 1772, p. 632, No. 5. Tensor membrane posterioris ale. Wiedemann, p. 85; Tiedemann, § 267. ” ” 9 3 Riidinger, p. 91. 9s és s a Selenka, No. 50. Spanner der hinteren Flughaut. Meckel. MM. plice alaris posteriorts. Schopss, p. 79, No. 1. M. coraco-brachialis brevis (pt.). Milne-Edwards, Ossem. fossil. M. expansor secundariorum. Garrod, P.Z.8., 1876, pp. 193, 194, und 199. % +5 re Forbes (Tubinares, p. 29). M. metapatagialis. Fiirbringer.” —(June 14, 1889, R.W.S.) In October 1887, I published in Zhe Journal of Comparative Medicine and Surgery (New York) an essay in which was reviewed the muscles used in the classification of Birds (see No. 124 of Biol. at end of the present volume), and there I made the following comments, and said that “the expansor secundariorum (Fig. 35 bis, Exp. Sec.), although of insignificant size, is a muscle that has proved of no little value as a classificatory one. Garrod spoke of it as the Ciconine character, as it was so well developed in the Storks. It occurs in quite a large number of groups of birds, as the Galline ; the Ducks, Geese, and Swans ; the Rails, Plovers, and many others. While ‘in the majority of the Gallinaceous birds the expansor secundariorum, with the normal origin from the secondary quills, has a different method of insertion, which has led Mons, A. Milne. Edwards to describe the muscle in the Common Fowl as a part of the coraco-brachialis (brevis) in his superb work on fossil birds’ (Garrod). ‘Professor Sutton alludes to this muscle in the following interest- 80 THE MYOLOGY OF THE RAVEN. origin or insertion upon any of the bones of the arm, or the shoulder-girdle, as muscles of the upper extremity. For we cannot clear the subject of this part of its anatomy until these are disposed of, and described. 52. The latissimus dorsi. 60. The subclavius. 53. The trapezius. 61. The coraco-brachialis. 54. The rhomboideus. 62. The teres minor. 55. The coraco-humeralis. 63. The levator scapule. 56. The scapulo-humeralis. 64. The thoraco-scapularis. 57. The supraspinatus. 65. The subscapularis. 58. The teres et infraspinatus. 66. The serratus parvus anticus. 59. The serratus magnus anticus. ing way. He says, ‘ Every student of human anatomy must have experienced a certain amount of curiosity when he dissected for the first time the plantaris muscle ; this strange structure sinks into in- significance when compared with the celebrated ambiens of the bird’s leg, or the tendon of the femoro-caudal in the Lacertilia. Of all strange muscles, the one known as the expansor secundariorwm (Garrod) in the bird's wing, stands pre-eminent. It is a small triangular muscle, arising from the quills of the last few secondary remiges at the elbow. Its remarkably long and slender tendon, which frequently traverses a fibrous pulley on the axillary margin of the ¢eres muscle, runs up the arm side by side with the axillary vessels and nerves, to be inserted in the thorax into the middle of a tendon, which runs from the inner side of the middle of the scapular element of the scapulo-coracoid articulation, to near the thoracic border of tie sterno-coracoid articulation, at right angles to it when the fore-limb is extended. “¢Tn the ducks and geese, among the Anseres, the tendons under consideration, when they enter the thorax, run towards one another and join (after having expanded out), in the middle line in front of the esophagus, and behind the trachea. ‘My investigations into the morphology of this tendon induce me to believe that it is the representative in the bird’s wing of the coraco-brachialis longus of mammals, and the long brachial ligament of man’ (Ligaments, their Nature and Morphology, p. 33). “This will prove a very interesting muscle indeed to search for in the various forms of bird life in our own United States avifauna.” THE MUSCLES OF THE UPPER EXTREMITY. 81 52. The latissimus dorsi,' next to the dermal muscles of the region, is the most superficial muscle of the dorsum. 1 From Gadow (loc. cit., pp. 226, 227) I obtain the following synonymy of the latissimus dorsi :— “68. M. LATISSIMUS DORSI. Grand dorsal. Vicq d’Azyr, 1772, p. 631. 33 5 Cuvier ; Gervais et Alix, p. 21. Hinterer anziehender Armmuskel und Riickwartszieher des Arms. Merrem, p. 153, Nos. 7, 8. Lutissimus dorsi und spinalis brachii. Wiedemann, pp. 84, 85. Latissimus dorsi. Tiedemann, § 252. 45 5 Heusinger, p. 183. Meckel, System, p. 313. Schopss, p. 103. 3 4 Reid, p. 141. Nitzsch-Giebel. Owen, Apteryx, p. 288. Selenka, p. 120, No. 45. De Man, p. 109. Fiirbringer, Morphol. Jahrb., v. Haswell, Proceed. Lin. Soc. New South Wales, 1880, p. 306 ff.; 1883, p. 115; id., Journal Anat. Phys., 1883, p. 219. Gadow (Pterocles, Tauben), Proc. Zool. Soc., 1882, p. 321. Watson, p. 87. i“ + Weldon, p. 641 ; Carlsson, p. 19. Breiter Riickenmuskeil (Riickwirtszieher des Oberarms). Prechtl, § 42, Latissimus dorsi + teres major. Haughton (Dromeus, p. 496). Rhea, p. 503 e, Fig. 35. Pars metapatagialis (Fiirbringer) = pt. Tensor membrane postertoris ale und M. plice alaris posterioris der Autoren.” 9 ” This author splits the latissimus dorsi up into “I. Der vordere Theil ; II. Der hintere Theil ; III. Die Pars metapatagialis.” These several divisions of the muscle as thus divided receive quite careful description at his hands, while for the physiology of the muscle he republishes the observations of Prechtl, as he does those of Firbringer for the comparative morphology. G 82 THE MYOLOGY OF THE RAVEN. It is well developed in a Raven, and as in the majority of birds, divided into two distinct slips. As a whole, however, it is a thin, fan-shaped muscle, or more properly speaking, a triangular one, with its apex at its insertion upon the humerus, and its base at its origin, attached to the vertebral spines. The anterior slip arises from the outer edges of the superior margins of the neural spines of that vertebra that bears the last pair of free ribs, and the one next succeeding it, whose ribs articulate with costal ribs; the posterior slip arises from the similar margins of all the following neural spines of the vertebree of the dorsum, which are four in number. This latter origin partakes very largely of a thin fascia-like character. From this combined origin, the fibres of the intimately connected slips rapidly converge as they pass directly to the humerus; they enter between the deltoid, the scapular head of the triceps, and the remaining heads of the latter muscle, to be inserted upon the shaft of that bone, on its anconal aspect, just within the margin of the radial crest, as a flat, ribbon-like muscle in this division of its course (Fig. 27). 53. The trapezius: lies immediately beneath the 1 Attention is invited in this connection to Gegenbaur’s Anat. des Menschen, 1883, p. 311. The following synonymy I take from Gadow (Bronn’s lassen, vi. Band, p. 217), who describes the trapezius under the name of the m. rhomboideus superficialis :— “65a. M. RHOMBOIDEUS SUPERFICIALIS, Trapézoide. Vicq d’Azyr, 1772, p. 630, No. 1. Trapeze. Cuvier ; Gervais et Alix, p. 21. Aufzieher des Schulterblatts. Merrem, p. 154, No. 9. Kappenmuskel s. Cucullaris, Wiedemann, p. 84. a ; 5 Tiedemann, § 242, ” ” 3 Schopss, p. 90. -s 3 Selenka, p. 107, No. 32. ‘Stun, ‘PrLrdeore, fel AMOD Aur Sos is ~on fap S24aU09 aeene 7XO eta. oor : LP - ODD tOD OUI SeL27 u w gq 2&oz0d 108009 OT Pr. ‘Jour ‘2x2 S2K|E Spway x s0rbu Fig. 27.—Anconal aspect of right humerus of a Raven, designed to show the areas of origin of the muscles attached to it. The os humero-scapulare is drawn in the position it normally occupies during life. The deltoid muscle is attached to it. Fic. 28.—A proximal view of the head of the same humerus. Fie. 29.—The same ; palmar aspect. Fic. 80.—The same ; radial aspect. . Fic. 31.—The same ; ulnar aspect. Figures are all life-size, and drawn by the author from his own dissections, G2 84 THE MYOLOGY OF THE RAVEN. latissimus dorsi for its posterior two-thirds, while the anterior or remaining third is superficial. The muscle is quite well-developed, consisting of a flat layer of fibres, of an oblong figure, which arise just below the latissimus dorsi, on the neural spines of the two vertebre that bear free ribs, and the next two succeeding vertebrae of the dorsum. From this origin the fibres pass directly across to the scapula to become inserted upon its mesial border to the extent shown in Figs. 8 and 24. The posterior moiety of the trape- zius overlies the anterior portion of the rhomboideus muscle, but the direction of their fibres is different, as those of the latter pass backward and outwards, while, as I have said, those of the present muscle pass directly across to their insertion (Fig. 33). 54. The rhomboideus! in man and most mammals Kappenmuskel s. Cucullaris. De Man, p. 103. Oberflichlicher Ein- und Riickwartszieher. Meckel, System, p. 306, No. 1. Trapezius. Watson, p. 76 ; Weldon, p. 641. Rhomboides pt. (cuculiaris). Fiirbringer, Morph. Jahrb., v. Rhomboides superficialis. Fiirbringer, Morph. Jahrb., xi., und Monographie. Rhomboideus inferior. Weldon, p. 641.” Gadow further adds (Bronn’s Klassen, p. 218) that “‘ Dieser Muskel, der bei den Vogeln passend als I. spini-scapularis bezeich- net werden kann, ist als ein oberflichlicher Theil des Rhom- boideus der Sauger zu betrachten, daher nicht, wie bisher fast allgemein geschehen, mit dem Cucullaris zu verwechseln. Zuriick- fuhriing auf Amphibien und Reptilien ist schwierig, da er wohl mit dem wahren Cucullaris eine noch nicht differenzirte Masse bildet, jedoch lasst er sich nach Fiirbringer mit der gleichnamigen Bildung der Crocodile homologisiren.” 1 “655. M. RHOMBOIDEUS PROFUNDUS. Rhomboide. Vicq d’Azyr, 1772, p. 630; Cuvier; Gervais et Alix, p. 21. THE MUSCLES OF THE UPPER EXTREMITY. 85 is represented by two distinct muscles, while in birds it is invariably a single one. It is absent altogether in the Apteryx. Here in the Raven, it arises from the neural spines of the first four dorsals, or at least from the spines of the leading four vertebre, that possess completed ribs. This origin lies beneath that of the latissimus dorsi and the trapezius muscles, where they overlap it. The fibres pass backwards and outwards to insert themselves upon the posterior third of the mesial border of the scapula, commencing anteriorly about where the trapezius leaves off, the overlapping of these two muscles, in all the specimens I have examined, being at their origins only. On the upper side of the shoulder-joint we find in the Raven two very slender muscular slips, passing from the shoulder-girdle to the humerus. They both act as levators of the brachium, and perhaps too, to a certain extent, counteract each other in pulling the humerus forwards and backwards. Rautenmuskel (rhomboideus). Wiedemann, p. 82. Meckel, System, p. 307. Schopss, p. 92. Selenka, p. 108, No. 33. De Man, p. 104. Watson, p. 77. 7 4 Carlsson, p. 17. Rhomboideus major et minor. Tiedemann, §§ 243, 244. Rhomboides pt. (rhomboideus). Fiirbringer, Morph. Jahrb., v. Rhomboideus profundus. Firbringer, Monographie. Rhomboideus superior. Weldon, p. 641.” (See Gadow in Bronn’s Klassen des Thier-Reichs, vi. Band, pp. 218, 219.) ” ” “Der Rh. profundus stellt eine secundire Differenzirung des Serratus profundus dar, die bei manchen Végeln (z. B. mehreren Ratiten) noch keine volle Selbststindigkeit gewonnen, bei anderen (z. B. Pici und Capitoniden) noch weiter gehende Sonderungen und Zerfallbildungen erkennen lisst ” (Fiirbringer). 86 THE MYOLOGY OF THE RAVEN. As a rule, these muscles are not fully described in works devoted to the myology of birds, and until such time as the homologies in myology are better known, I have bestowed the following names upon these two little muscular slips :— 55. The coraco-humeralis,! the smaller and more anterior of the two, arises from the outer side of the head of the coracoid, above and rather posterior to the origin of the long head of the biceps (Fig. 24, c.h.). Its fibres form a delicate, subcylindrical cord that passes to the head of the humerus to become inserted upon its palmar aspect, beyond and to the inner side of the insertion of the pectoralis major (Fig. 29). 56. The scapulo-humeralis* (Fig. 8) arises from the 1 Fiirbringer defines this muscle as the coracobrachialis anterior s. externus, in his magnificent work upon the morphology of the class Aves ; and Gadow presents us with the following synonymy :— “75. MuscuLus CORACO-BRACHIALIS ANTERIOR. Le muscle qui correspond aw coraco-brachial. Vicq d’Azyr, 1773, p. 568, No. 5. Deltoideus inferior. Schopss, p. 122, No. 20 (partim). Deltoideus minor. Heusinger, p. 183, No. 6. Coraco-brachialis proprius s. pectoralis medius. Riidinger, p. 89. Deltoideus minor. Selenka, p. 117, No. 43. Coracobrachialis anterior s. externus. Fiirbringer (Joc. cit., p. 251).” 2 According to Gadow (loc. cit., p. 234) this muscle represents the deltoideus minor of Fiirbringer, and he gives the following synonymy of it :— “70. M. DELTOIDEUS MINOR, Le petit releveur de Vhumerus. Vieq d’Azyr, 1773, p. 567. Levator humeri. Tiedemann, § 255 (1). 3 95 Heusinger, p. 183, No. 7. Deltoideus externus. Schopss, p. 120, No. 19. Kleiner deltaférmiger Muskel (Vorwirtszieher des Oberarmes). Prechtl, § 39. Deltoideus minor. De Man, p. 108. THE MUSCLES OF THE UPPER EXTREMITY. 87 inner side of the neck of the scapula just within the origin of the deltoid; its fibres form a narrow, flat- tened ribbon, that passes over the top of the shoulder- joint, parallel to the upper margin of the larger portion of the deltoid, to become inserted on the palmar aspect of the humeral head, directly between the insertions of the pectoralis major and secundus (Fig. 33, s.h.). Professor Owen describes for the Apteryx a sub- scapularis muscle as arising “from the anterior part of the inner surface of the scapula, and is inserted into the ulnar humeral tuberosity.” I might have considered this the same as the muscle described above as my scapulo-humeralis, but the eminent anatomist just quoted says further that the sub- scapularis is divided into two portions by the pec- toralis minor. Unfortunately, I have not Professor Owen’s drawings of the myology of Apteryx before me at the present writing, but it is difficult for me to understand from his description in The Anatomy of Vertebrates, how the muscle he calls the subscapularis can be “ divided into two portions by the pectoralis minor,” when he says of the latter that “A muscle, which may be regarded either as a portion of the pectorals minor, or as the analogue of the subclavius muscle, arises from the anterior angle of the sternum, and is in- serted into the external margin of the sternal extremity Deltoideus minor.. Firbringer ; Carlsson, p. 20. Accessoire coracoidien du sus-spineux. Alix, p. 399 ()).” Considerable confusion has attended the identification of this muscle, and the deltoideus minor of Selenka (Bronn’s Klassen, vi. Band, p. 117) is not taken by Gadow to be the muscle he describes under that name, and the present writer is satisfied that the d. ininor of Gadow is the muscle described above as the scapulo humeralis. 88 THE MYOLOGY OF THE RAVEN, of the coracoid bone” (Anat. Verts., vol. ii. p. 95). Of course it is hard for me to judge, as I say, in the absence of Professor Owen’s figure, but if the fibres of this subclaviws muscle have the same direction as his pectoralis minor, then it is hard to see how they could divide the subscapularis in two portions, which pass between the scapula and the humerus. (For the way these muscles occur in the Raven, see No. 60 et seq.) 57. The supraspinatus! (Figs. 24, 27, and 384) is a thin, flat muscle of a triangular form, its base being represented by its origin, and its apex by its insertion. It arises from the superior surface and outer 1 “Recht stark entwickelt ist der Muskel bei Corvus,” says Gadow, in speaking of the supraspinatus, which he describes in Bronn’s Thier-Reichs as the scapuli-humeralis anterior, with the subjoined synonymy (vi. Band, p. 235) :— “71a, M. SCAPULI-HUMERALIS ANTERIOR. Phuméro-scapulaire. Viog d’Azyr, 1773, p. 569. Schulterarmmuskel. Wiedemann, p. 86. ” Prechtl, § 41. Humero-scapularis parvus. Tiedemann, § 257. ” 9 3 Heusinger, § 184. Supraspinatus, oder Zeres minor? Meckel, System, p. 312, No. 6. 3 98 5 3 Schopss, p. 107. Teres minor. Reid, p. 142; Nitzsch-Giebel. Subscapularis (inferior posterior). Macalister, p. 16. Infraspinatus. Retzius, Selenka, p. 113, No. 38. s¥ De Man, p. 106; Carlsson, p. 19. Teres minor s. Infrascapularis. Gaurlt, p. 21. Le petit rond. Gervais et Alix, p. 22. Supraspinatus. Riidinger, p. 86. 5 Watson, p. 85. 5% Weldon, p. 643. Infraspinatus. Fiirbringer, Morph. Jahrb., v. Scapulo-humeralis anterior. Fiirbringer, Monographie.” THE MUSCLES OF THE UPPER EXTREMITY. 89 Fic. 32.—Anterior aspect of a number of muscles of the upper extremity, and more particularly designed to show in situ the pectoralis secundus and tertius, and the biceps. The pectoralis major has been almost en- tirely removed. a, the end of cut tendon of pectoralis secundus ; b, its humeral stump ; c, the humeral stump of the pectoralis major. Life-size, from an adult female Raven, by the author, from his own dissections. rounded margin of the scapula, posterior to the origin of the long head of the triceps, for about the anterior 90 THE MYOLOGY OF THE RAVEN. third of the blade of the bone. Its fibres converge to pass directly to the corresponding humerus, to become inserted upon the anconal aspect of the bone, just within the border of the lower part of the pneumatic fossa, below the origin of the deltoid, and between the forks of the external and internal heads of the triceps, which really seems to divide to give it space to make fast to, as shown in the figures. 58. The teres et infraspinatus! is the name I have 1 As will be seen in my Preface to the present volume, I was far removed from nearly all books, and from all libraries and anatomists, when it was written, and when this muscle was primarily described by me. So when the synonymy of these parts as collected by Gadow recently came to my hands, it was with no little interest that I noted that the muscle now under consideration, as proves to be the case in quite a number of others I was obliged under those circumstances to bestow names upon, had already received the name I coined for it by Tiedemann, by Heusinger, and by Schopss.— (14th June, 1889.) The following is its synonymy by Gadow (Bronn’s Klassen des Thier-Reichs, vi. Band, pp. 236, 237) :— “716. M. SCAPULI-HUMERALIS POSTERIOR. Sus-scapulaire. Vieq d’ Azyr, 1772, p. 631. Schulterblattmuskel. Merrem, p. 154; Prechtl, § 38. Ober-Schulterblattmuskel. Wiedemann, p. 87. Supra-scapularis (Infraspinatus + teres major). Tiedemann, § 256. 53 si Pr 3 Heusinger, p. 184. Suprascapularis. Gurlt, p. 21. Untergritenmuskel. Meckel, System, p. 312, No. 5. Infraspinatus s. teres major. Schopss, p. 105. Infraspinatus. Reid, p. 141; Owen, Apteryx, p. 288; Watson, p. 86. Leres major. Retzius ; Selenka, p. 113, No. 37 ; De Man, p. 105. SS Fiirbringer, Morph. Jahrb., v. ; Carlsson, p. 19. Teres minor. Macalister, p. 16. Le grand rond, Gervais et Alix, p. 22. ie a Alix, p. 394, Scapulo humeralis posterior. Fiirbringer.” THE MUSCLES OF THE UPPER EXTREMITY. 91 bestowed upon the present muscle, as it seems to com- bine the teres major and the supraspinatus of such vertebrates wherein these muscles are found separate. Even in old muscular subjects among the Ravens, one is almost led to believe that the two can be fairly dis- tinguished, the division being indicated by a somewhat broader dividing fascia. The teres et infraspinatus possesses fully four or five times the bulk of the supraspinatus, and is the largest muscle, by all odds, that is attached to the shoulder-blade (see Figs. 24, 27, and 34). It arises from the superior surface and the outer margin of the hinder two-thirds of the scapula, extending in fact between the posterior termination of the supra- spinatus to the apex of the bone. Its fibres rapidly converge as they pass forwards and outwards to their point of insertion upon the corresponding humerus. This is found upon the anconal surface of that bone at about the middle of the free ulnar margin of the pneumatic fossa; the external head of the triceps forking to allow this muscle room to attach itself (Fig. 27). Owen says in the Apteryx that it “is inserted into the ulnar tuberosity of the humerus, where it is closely attached to the capsule of the shoulder-joint.” The major portion of both of these last-described muscles lie beneath the latissimus dorsi, the supra- spinatus being the less covered of the two (Fig. 33). Chief among the uses of these muscles is the protection they afford the shoulder-joint, and acting as braces they greatly assist keeping the humerus in its shallow socket. After the wing has been extended, they, by their contraction, assist to close it again by drawing the humerus towards the side of the body. They are 92 THE MYOLOGY OF THE RAVEN. also useful in some of the movements of the brachium during flight; and it must be evident to meet any of these ends, the supraspinatus is the one possessing the least power, while the teres et infraspinatus, from its greater size and more favourable origin, is the more powerfully endowed. 59. The serratus magnus anticus! is composed of 1 In dealing with the serrati group of muscles in birds, Gadow divides his m. serratus superficialis s. thoraci-scapularis into three parts, viz.:—I. the pars anterior, II. the pars posterior, and III. the pars metapatagialis. His work (Bronn’s Klassen, vi. Band, pp. 221-224) presents descriptions of these several divisions, to which the student is referred, and records the subjoined synonymy, herewith republished :— “660. M. SERRATUS SUPERFICIALIS 8. THORACI-SCAPULARIS. “T. Pars anterior. Costo-scapulaire. Vicq d’Azyr, 1772, p. 629; Cuvier. Costo-scapularis inferior. Wiedemann, p. 87. Costo-scapularis. Tiedemann, § 247. Kleiner Brustmuskel oder vorderer sigeférmiger Muskel. Meckel, System, p. 308, No. 7; Schopss, p. 96. Serratus magnus anticus ( first portion). Owen, Apteryx, p. 288. Serratus anticus (pt.). Selenka, p.110, No. 35. 99 “ 5 De Man, p. 105; Carlsson, p. 18. Grand dentelé antérieur. Gervais et Alix, p. 20. Serratus anticus minor. Watson, p. 78. Serratus superficialis, pars anterior. Fiirbringer. “II. Pars posterior. Sous-scapulaire. Vicq d’Azyr, 1772, p. 632. Grand dentelé. Cuvier. Riickwirtszieher des Schulterblattes. Merrem, p. 154. Serratus. Wiedemann, p. 87. Serratus magnus. Tiedemann, § 246. 5 Fiirbringer, Morph. Jahrb., v. ” ” Weldon, p. 641. Grosser, vorderer Sigemuskel. Meckel, System, p. 308, No. 6. os ” a Schopss, p. 94. THE MUSCLES OF THE UPPER EXTREMITY. 93 three strong digitations, each of considerable bulk. The first of these slips arises from the outer aspect of the second true dorsal rib (counting from before backwards) rather above the base of its epipleural appendage. The other two slips arise from similar points on the next two succeeding ribs, just above the origin of the dermo-ulnaris. The extremities of these digitations of the serratus magnus anticus, are strongly inclined to partake of a tendinous character, and the first two may be more or less attached to the interpleurapophysial membrane. They converge as Serratus magnus anticus (middle and posterior portion). Owen, Apteryx, p. 288. Serratus anticus (pt.). Selenka, p. 110, No. 35. 5 = ; De Man, p. 105. Grand dentelé postérieur. Gervais et Alix, p. 20. Serratus anticus major. Watson, p. 77. Serratus superficialis, pars posterior. Fiirbringer. “TIT. Pars metapatagialis. Fiirbringer. (pt.) Tensor membrane posterioris ale. Wiedemann ; Tiedemann, § 267. ” ” ” » Riidinger, p. 91. ” ” a » Selenka, p. 123, No. 50; Carlsson, p. 18. (pt.) M. plice alaris posterioris. Schipss, p. 79.” If the reader will refer to my dermo-ulnaris (No. 11 of the present work) he will find that that muscle represents the pars metapatagialis of the above synonymy ; so that the synonyms here will probably stand thus— S#UFELDT. Gapow. No. 59, Serratus magnus anticus = I. Pars anterior. No. 64, Thoraco-scapule (in pt.) No. 66, Serratus parvus anticus = II. Pars posterior. (in part) No. 11, Dermo-ulnaris = III. Pars metapatagialis. ee M. serratus 668 superficialis s. thoraci-scapularis. 94 THE MYOLOGY OF THE RAVEN. they pass upwards and slightly forwards, and are inserted on the inferior surface cf the apex of the corresponding scapula (see Figs. 24, 34, and others). 60. The subclavius+ muscle arises from the entire outer surface of the costal process of the sternum and the contiguous outer surfaces of three or four of the hemapophyses, in which situation it is largely over- lapped by the pectoralis tertius. Its outermost sheath of fascia is attached to the inferior external margin of the corresponding coracoid bone, but its short and oblique muscular fibres pass over this to be inserted and fill the fossa that is found at the lower third of the posterior aspect of the coracoid. When this muscle contracts it simply pulls the coracoid very slightly outwards, the bone sliding along upon the articulation of its sternal bed. The more important function of 1 Both Fiirbringer and Gadow describe this muscle as the sterno- coracoideus, while originally it was considered by Tiedemann and Schopss to be the subclavius. Gadow presents us with the following synonymy for it (Bronn’s Klassen des Thier-Reichs, vi. Band, pp. 224, 225) :-— “67. M. sTERNO-CORACOIDEUS. Le claviculaire court. Vicq d’Azyr. Riickwartszieher der Schliisselbeine. Merrem. M. clavicularis externus. Wiedemann. M. subclavius. Tiedemann, § 248. es 35 Schopss. Ohne Namen, oder vielleicht kleimer vorderer Sigemuskel. Meckel, System, p. 308, No. 8. Pectoralis minor. Retzius. Subclavius s. pectoralis minor. Riidinger, p. 89. Serratus anticus minor. Owen, Apteryx, p. 288. Coraco-sternalis. Selenka, p. 111, No. 36. 4 9 De Man, p. 105 ; Carlsson. Sterno-coracoideus. Fiirbringer, Morph. Jahrb., v., xi.. und Mono- graphie.” THE MUSCLES OF THE UPPER EXTREMITY. 95 the muscle consists in keeping the coracoid firmly in place and preventing its dislocation during violent action of surrounding muscles (see Figs. 8 and 25). 61. The coraco-brachialis} (Figs. 8 and 27) is a long fusiform muscle that arises by a delicate tendon 1 My dissections of the coraco-brachialis in Corvus convinced me that it had the same origin and insertion described for it by Owen (Anat. Verts., vol. ii. p. 97); but I find that Gadow, who calls the muscle the subcoracoideus, finds a different arrangement of things, for he says that, “Bei Corvus, Garrulus, und Paradisea entspringt ein Theil von Binnenseite und dem Vorderrander des Sternum und von der Innenflache des benachbarten Coracoidtheiles ; ein anderer Theil kommt vom Proc. furcularis des Coracoids und der Scapula. Beider Theile Sehnen inseriren sich vereinige dicht am Caput humeri etwas proximal von der Sehne des Subscapularis” (Bronn’s Klassen des Thier-Reichs, vi. Band, p. 239). Gadow agrees with Owen in that the coraco-brachialis is missing in Struthio and small in the Apteryx. He presents us with the following synonymy for it (loc. cit., p- 238) :— “72a. M. SUBCORACOIDEUS. Souclavier interne. Vicq d’Azyr, p. 628. Vorderer anziehender Armmuskel. Merrem, p. 153. Ohne Namen. Meckel, System, p. 320, No. 13. Coraco-brachialis superior. Schodpss, p. 115, No. 17. Coraco-brachialis brevis. Milne-Edwards ; Selenka, p. 115, No. 41. 5 9 ay De Man, p. 106 (2. Portion) ; Carlsson, p. 18. Coraco-brachialis. Owen, Apteryx, p. 289 ; Watson, p. 84; Gurlt. Daccessoire coracoidien du sous-scapulaire. Gervais et Alix, p. 23. Coraco-brachialis externus. Fiirbringer, Morph. Jahrb., v. Sub-coraco-scapularis (Pars coracoidea) = M. subcoracoideus. Fiir- bringer, Morph. Jahrb., xi., und Monographie.” Authors appear to describe two portions of this muscle, of which my coraco-brachialis is one; Selenka says of his Coracobrachialis brevis (No. 41) that “Die dlteren Beschreibungen dieses Muskels sind simmtlich mangelhaft und verwirrt, viele sonst ausfithrliche Arbeiten nennen ihn nicht einmal. Cuvier spricht nur allgemein 96 THE MYOLOGY OF THE RAVEN. from a small circular origin situated at the postero- mesial aspect of the shaft of the coracoid, immediately above the fossa which harbours the insertion of the subclavius. Its fibres pass almost directly upwards parallel with the coracoidal shaft, and as they near the head of the humerus they again become tendin- ous, and are finally inserted on the top of the ulnar tuberosity, on a diminutive subcircular space, common to it and the insertion of the teres minor. Owen tells us that “This muscle is wanting in the Struthionide, is of small size in the Heron and Goose, is much more developed in the Raptores and many Natatores, especially the Penguins, and attains its greatest relative size in the Rasores, where it arises from almost the whole of the coracoideum.” 62. The teres minor! arises fleshy from the under side of the anterior tip of the scapula, the clavicular process of the bone, to the extent shown in Fig. 8. The fibres, forming a chunky, little muscle, pass directly outwards, behind the coracoidal head, and beneath the neck of the scapula. Clearing these two bones the fibres rapidly converge to form a small tendon, which is intimately fused with the tendon of the coraco-brachialis, and consequently makes the same von zwei Muskeln, die am Os coracoideum entspringen und am Humeruskopfe sich inseriren; das sind die beiden hier als Coracobrachiales beschriebenen Muskeln. Tiedemann fiihrt einen Deltoideus minor und Levator humeri auf, dei zum Theil wenigstens dem Coracobrachialis brevis entsprechen. Auch Gurlt, Wiedemann, Merrem, Aldrovandi erwaéhnen den Muskel nicht” (Bronn’s Klassen des Thier-Reichs, vi. Band, p. 115). 1 Possibly this muscle corresponds to the subscapularis internus of Gadow’s “726. M. supscapuLaRis,” and attention is invited to the muscle I describe below asthe subscapularis (No. 65), and the footnote under it. THE MUSCLES OF THE UPPER EXTREMITY. 97 insertion on the top of the ulnar tuberosity of the corresponding humerus. To a limited degree, the coraco-brachialis and teres Fic. 33.—Superficial muscles of the upper extremity in the region of the shoulder and dorsum of a Raven. s, scapula; a, anterior slip of the latissimus dorsi ; p, its posterior slip. The head of the coracoid can be seen where the mesial extremities of the patagii muscles pass over it; s.., the scapulo-humeralis muscle. The extensor metacarpi radialis longus muscle is indivated by the letters e.m.r.J. Life-size, by the author, from his own dissections. minor assist the pectorals in their action in the down- ward stroke of the humerus, and so the wing, but they also assist in keeping that bone in its shallow glenoid cavity. H 98 THE MYOLOGY OF THE RAVEN. In all of the works at my disposal I fail to find a description of this teres minor muscle, and consequently have taken the responsibility of naming it myself. In its origin, insertion, and action, it seems to corre- spond quite closely with the teres minor of many of the higher vertebrates, in arising near the neck of the scapula and being inserted upon the tuberosity of the humerus. Mivart says that the teres minor may coalesce with the infraspinatus, as in the Two-toed Ant-eater. The minor may be larger than the major, as in the Horse (Elem. Anat., p. 326). 63. The levator scapule! arises by two strong, fleshy digitations, one from each of the lateral processes 1 This is the serratus profundus of Fiirbringer and Gadow, and the latter presents us with a very full description of it (loc. cit., pp. 220, 221), together with the following synonymy :— “ 66a. M. SERRATUS PROFUNDUS. Anzieher des Schulterblattes. Merrem, p. 154. Costo-scapularis superior. Wiedemann, p. 87. Levator scapule. Tiedemann, § 245. 5 99 Selenka, p. 109, No. 34. 3 FP De Man, p. 104; Fiirbringer, Morph. Jahrb., v. ; Watson, p. 79; Weldon, p. 641; Carlsson, p. 17. Schulterheber. Meckel, System, p. 307. is Schopss, p. 97. Pangulaire. Gervais et Alix, p. 20. Serratus profundus, Fiirbringer. “ Riidinger bemerkt ganz richtig, dass in Folge seines Ursprungs von den Rippen dieser Muskel eine wesentliche Abweichung vom Levator scapule der Saiiger bietet, da er bei letzteren von den hinteren Zacken der Querfortsitze der ersten 4 Halswirbel ent- springt. Er entspringt dagegen ziemlich genau dem MM. collo- scapularis der Reptilien, wenn man die Linge des Vogelhalses in Betracht zieht. Der Serrat. prof. (Levator scapule der Autoren) THE MUSCLES OF THE UPPER EXTREMITY. 99 of those vertebree that support the free pairs of ribs ; the fibres slightly converge as they pass directly back- wards to become inserted into the middle third of the inferior aspect of the blade of the corresponding scapula. When this pair of muscles contracts they will evidently pull the scapule directly forwards, and with it, of course, the entire shoulder-girdle, which will articulate like a hinge-joint at the coraco-sternal junction. Owen says that “the levator scapule arises by digi- tations from the pleurapophyses of the last cervical, and the first two dorsal vertebre ; it is inserted into the posterior part of the dorsal edge of the scapula, which it pulls forwards. In the Apteryx it seems to be the most anterior portion of the series of fasciculi composing the serratus magnus anticus.” It will be seen from this description that both its origin and inser- tion is very different in the Kiwi-kiwi from what it is in the Raven. 64. The thoraco-scapularis! is the name I here be- stow upon that muscle in Corvus coraxz which arises from the outer aspect of the lower half of the ultimate free rib ; from the middle of the outer side of the next succeeding rib, or true dorsal, and its epipleural zeigt in Gegensatze zu den Reptilien namentlich bei den Carinaten eine gewisse Vereinfachung, die z. Th. dadurch entstanden ist, dass ein Theil von ihm sich als besonderer Muskel (Rhomboideus pro- fundus) differenzirt und abgetrent hat” (Gadow quoting Fiirbringer, . 221). 2 : tai the muscle here described is the pars posterior (in part) of Gadow’s m. serratus superficialis s. thoract-scapularis, the synonymy of which is given under the serratus magnus anticus of the present memoir, No. 59 (which see). The remaining part of the pars posterior of Gadow’s m. serratus superficialis, appears to be herein represented by my serratus parvus anticus (No. 66), and the reader’s attention is also invited to that muscle. H 2 100 THE MYOLOGY OF THE RAVEN. appendage; and finally by another digitation, the largest of the three, from a like origin on the outer surface of the following rib. These three digitations form a broad, flat muscle lying close against the parietes of the thorax. Its fibres converge and pass upwards and forwards, but as they enter the scapulo-thoracic space they become converted into a broad, thin, flat tendon, which, passing between the two divisions of the sub- scapularis, is inserted on a line, covering the junction of the middle and anterior thirds of the outer margin of the corresponding scapula (Fig. 24). This muscle, when the ribs are fixed, draws down the scapula to the side of the chest, but when the shoulder-girdle is fixed by the opposing set of muscles, it draws up the ribs to which it is attached, and thus increases the capacity of the chest, and performs an important function in the act of inspiration. From what I quoted from Sir Richard Owen, above, it would seem that this muscle corresponded with his pectoralis minor, and if we be permitted to compare the two, it seems to correspond even with the pectoralis minor in a man, but a far greater amount of study will have to be undertaken than has been done up to the present time, before we can say much about such homologies. Mivart says of the pectoralis minor that “ the smaller pectoral is a much less constant muscle than the large one, being very frequently absent. Even in animals closely allied to man (e.g. many Apes) it is in- serted into the capsular ligament of the humerus instead of into the coracoid process. It may form one with the pectoralis major, as in birds” (Klem. Anat., p. 326). It will be seen that this last statement of this authority cannot be reconciled with what we have found to be the TIIE MUSCLES OF THE UPPER EXTREMITY. 101 case in the Raven and many other birds. Any way we may regard it, however, the fact still remains that in many vertebrates, we have a muscle that passes from the middle outer surfaces of some of the leading ribs, to become attached to some part of the shoulder-girdle, or scapular apparatus, and that this muscle is an important one in inspiration. We may call it the pectoralis manor, or the thoraco-scapularis, as I have in the present instance, as we may please. 65. The subscapularis} is one of the largest and most powerful of the muscles in the Corvide, and is well 1 See No. 62 of the present memoir in this connection (the teres minor), and the muscle here described appears to be the I. (subscap. eaternus) of Fiirbringer and Gadow, or in other words, as near as I can make it out, my teres minor + (my) subscapularis = the subscapularis (with internal and external part) of Firbringer. Gadow (Bronn’s Klassen, vi. Band, pp. 240, 241) presents us with the following valuable study of the subject :— “726. M. suBSCAPULARIS. Sousclavier externe. Vicq d’Azyr, 1772, p. 628. Vorderer anziehender Armmuskel. Merrem. Sous-scapulaire. Cuvier ; Gervaiset Alix, p. 22. Unter-Schulterblattmuskel (subscapularis). Wiedemann, p. 89 ; Schépss, p. 128, No. 22; Meckel, System, p. 321. ? Deltoideus externus. Schopss. Subscapularis. Reid, p. 142. e Riidinger, p. 87. * Macalister (superior posterior), p. 16.