LIBRARY OF THE UNIVERSITY OF CALIFORNIA. LIBRARY Class 6 * THE GROUSE IN HEALTH AND IN DISEASE VOLUME I Frontispiece. ( P.Z.S. 1910. PI. LXXVIII. ) AnOi-c & Sleigh, Lid. PAIR OF RED GROUSE IN SUMMER WITH YOUNG CHICKS. THE GROUSE IN HEALTH AND IN DISEASE BEING THE FINAL REPORT OF THE . COMMITTEE OF INQUIRY ON GROUSE DISEASE \> VOLUME 1 WITH 59 FULL PAGE PLATES, MOSTLY IN COLOUR AND 31 ILLUSTRATIONS IN THE TEXT LONDON SMITH, ELDER & CO., 15 WATERLOO PLACE 1911 [AH rights reserved] . BIO! DEDICATED BY GRACIOUS PERMISSION TO 1bi0 flDajestp tbe Iking. 222648 TABLE OF CONTENTS VOLUME I. CHAI'TEK Introduction. By LORD LOVAT xi PART I. THE NORMAL GROUSE. I. The Systematic Position of the Grouse. By A. H. EVANS .... 1 II. The Life History of the Grouse. By A. S. LESLIE 5 III. The Changes of Plumage in the Red Grouse in Health and in Disease. By EDWARD A. WILSON 29 PART I. PLUMAGE CHANGES IN THE COCK. PART II. PLUMAGE CHANGES IN THE HEN. PART III. LOCAL VARIATIONS IN THE PLUMAGE OF THE GROUSE. IV. Food of the Red Grouse 67 PART I. OBSERVATIONS ON THE FOOD OF GROUSE, based on an examination of crop contents. By EDWARD A. WILSON. PART II. THE INSECT FOOD OF GROUSE CHICKS, based on an examination of crops and gizzards. By PERCY H. GRIMSHAW. PART III. WATER. By A. S. LESLIE. PART IV. GRIT. By Dr H. HAMMOND SMITH AND R. H. RASTALL. V. Physiology and Anatomy of the Red Grouse. By EDWARD A. WILSON . 100 VI. The Weight of Grouse. By EDWARD A. WILSON 130 PART II. THE GROUSE IN DISEASE. VII. Causes of Mortality in the Red Grouse. By LORD LOVAT and EDWARD A. WILSON . 147 VIII. Causes of Mortality in the Red Grouse continued. By EDWARD A. WILSON .... . .152 PART I. THOSE REFERABLE TO ARTIFICIAL CONDITIONS. PART II. THOSE REFERABLE TO NATURAL CAUSES. IX. Grouse Disease. By EDWARD A. WILSON and A. S. LESLIE . . . .185 HISTORY OF GROUSE DISEASE with an account of the work of the Grouse Disease Inquiry in respect of previous work done by Professor Klein, Dr Cobbold, and others. vii viii TABLE OF CONTENTS CHAPTER 1'AOB X. Grouse Disease continued Strongylosis . . .207 PART I. THE THREADWORMS (NEHATODA). By Dr A. E. SHIPLEY. PART II. ON THE DEVELOPMENT AND BIONOMICS OF TRICHOSTRONGVLUS PERORACILIS. By Dr R. T. LEIPEH. XL Grouse Disease continued CoGcidiosis. By Dr H. B. FANTHAM . . . 235 PART I. THE MORPHOLOGY AND LIFE HISTORY OF EIMERIA (COCCIDIUM) AVIUM, a sporozoon causing a fatal disease among young Grouse. PART II. EXPERIMENTAL STUDIES ON AVIAN COCCIDIOSIS, especially in relation to young Grouse, fowls, and pigeons. PART III. COCCIDIOSIS IN GAME BIRDS AND POULTRY : Some Preventive Measures and Treatment. XII. Grouse Disease continued Pathology. By Dr L. COBBETT and Dr G. S. GRAHAM-SMITH .... . 273 XIII. Observations on the Blood of Grouse. By Dr H. B. FANTHAM . 308 XIV. Observations on the Parasitic Protozoa of the Red Grouse (Lagopus scoticus) with a Note on the Grouse Fly. By Dr H. B. FANTHAM . 318 XV. The Tapeworms (Cestoda) of the Red Grouse (Lagopus scoticus} By Dr A. E. SHIPLEY . . 334 XVI. The Ectoparasites of the Red Grouse (Lagopus scoticus). By Dr A. E. SHIPLEY . . . 347 PART III. MANAGEMENT AND ECONOMICS OF GROUSE MOORS. XVII. Moor Management. By LORD LOVAT . . . . 372 XVIII. Heather-burning 1 . By LORD LOVAT. . . . . . 392 XIX. The Heather Beetle. By P. H. GRIMSHAW . . 414 PART I. ON "FROSTED" HEATHER AND ITS CONNECTION WITH THE HEATHER BEETLE (LOCHM.EA SUTURALIS). PART II. THE LIFE HISTORY OF THE HEATHER BEETLE. XX. Keepers and Keepering, with sub-divisions dealing with Poachers and Vermin. By LORD LOVAT .... ... . 430 XXL Stock. By LORD LOVAT . . 454 XXI L Grouse in Captivity. By Dr H. HAMMOND SMITH . . . 483 XXII L Value of Grouse Shootings in Great Britain By A. S. LESLIE . . 491 Index . 503 LIST OF ILLUSTRATIONS PLATE I. PAIR OF RED GROUSE IN SUMMER WITH YOUNG CHICKS .... Front I apiece II. MALE GROUSE, BLACK TYPE, IN FULL WINTER PLUMAGE . . . tofaeejJOge 34 III. MALE GROUSE, RED TYPE, IN FULL WINTER PLUMAGE .....,, 34 IV. MALE GROUSE, WHITE SPOTTED BIRD OF RED TYPE .....,, 34 V. MALE GROUSE, RED TYPE, IN FULL WINTER PLUMAGE WITH A FEW BLACK CENTRED FEATHERS OF THE PREVIOUS AUTUMN PLUMAGE .....,, 35 VL MALE GROUSE SHOWING MARKED BEGINNING OF THE AUTUMN PLUMAGE ON HEAD AND NECK . . . . . . . . . . . ,, 36 VII. MALE GROUSE CHANGING FROM WINTER TO AUTUMN PLUMAGE . . ,, 36 VIII. FEMALE GROUSE, BLACK TYPE, IN AUTUMN PLUMAGE ...... 44 IX. FEMALE GROUSE, RED TYPE, CHANGING FROM WINTER TO SUMMER PLUMAGE . ,, 45 X. FEMALE GROUSE IN FULL BREEDING PLUMAGE ......,, 45 XI. FEMALE GROUSE IN FULL SUMMER PLUMAGE . . . . . . 46 XII. FEMALE GROUSE, RED TYPE, FEATHERS FROM FLANKS .....,, 46 XIII. FEET OF RED GROUSE: (1) NEW WINTER FEATHERS AND NAILS; (2) FULL WINTER PLUMAGE ; (3), (4), (5) AND (6) SHOWING STAGES IN MOULTING OF NAILS . ,, 46 XIV. FEMALE GROUSE, SHOWING BARE PATCH OF SKIN AND DOUBLE LINE OF BARRED FEATHERS ON ABDOMEN . . . . . . . . . ,, 47 XV. FEMALE GROUSE, RED TYPE, WORN UPPER TAIL COVERTS . . . . ,, 47 XVI. HEADS OF (1), (2), FEMALE GROUSE; (3), (4), MALE GROUSE; (5) PTARMIGAN SHOWING SUPRA-ORBITAL COMBS ......... 48 XVII. HEAD OF BLACKCOCK SHOWING SUPRA-ORBITAL COMB .....,, 49 XVIII. MALE GROUSE SHOWING ABNORMAL ERYTHHISM ....... 60 XIX. FEMALE GROUSE, BUFF-BARRED TYPE . . . . . . . ,, 60 XX. FEMALE GROCSE, ABNORMAL YELLOW VARIETY . . . . . ,, 60 XXI. FEMALE GROUSE, GREY VARIETY ........,, 60 XXII. FEMALE GROUSE, GREY VARIETY . . . . . . . . ,, 60 XXIII. TYPES OF HEATHER . . . . . . . . . . ,, 71 XXIV. PLANTS EATEN BY .THE GROUSE (4 Figures) ......,, 86 XXV. PLANTS EATEN BY THE GROUSE (4 Figures) . . . . . 87 XXVI. DIAGRAM OF ALIMENTARY TRACT ........,, 101 XXVII. ALIMENTARY TRACT, C.ECUM, RECTUM, GIZZARD, DUODENUM, SMALL INTESTINE . ,, 102 XXVIIrt. ALIMENTARY TRACT I If SITU . . . . . . . . ,, 103 XXVIII. OECUM, DUODENUM, ETC. . . ...'... 104 XXIX. RECTUM AND SMALL INTESTINE ........,, 115 XXX. C^ECA .............. 117 xxxi. C;ECA AND KIDNEYS ............ 118 TEXT-FIG. 1. FRACTURED HUMERUS AND SCAPULA RE-UNITED .... page 154 ,, 2. THE SAME BONES UNINJURED . . . . . . ,, 154 ,, 3. FRACTURED AND RE-UNITED BREASTBONE OF A GREY HEN . . 158 ix LIST OF ILLUSTRATIONS TEXT-FIG. 4, 5. FRACTURED AND RE-UNITED BREASTBONE VIEWS OF RIGHT AND LEFT SIDE ......... 6. FRACTURED AND HE-UNITED BREASTBONE SHOWING METHOD OF UNION 7, 8. BROKEN AND RE-UNITED WING-BONES . . . . . 9-11. BROKEN AND RE-UNITED LEG-BONES . . . . . 12-15. BROKEN AND RE-UNITED THIGH-BONES ..... XXXII. BUMBLEFOOT IN GROUSE ........ XXXIII. TR1CHOSTRONGYLUS 1'ERGRACILK AND TRICHOSUMA I.ONGKOLLK (5 Figures) TEXT-FIG. 16. MORUL^E IN EGG OF TRICHOSTRONGYLUS PERGRACILIS . ,, 17, 18. DEVELOPING OVA OF T. PERGRACILIS . . . . . ,, 19, 20, 21. FORMATION OF THE LARVA OF T. PBRGRACILIS . ,, 22, 23. EMBRYOS OF T. PERGItACILIS HIGHLY MAGNIFIED . 24-27. CHANGES IN T. PERGRACILIS DURING ECDYCIS AND EXCYSTMENT . ,, 28, 29. LARVAL FORMS OF T. PKRGRACILIS . . . . . ,, 30. ENCYSTED LARVAE OF T. PERGRACILIS . . . . . XXXIV. EIMERIA (COCCIDIUM) AVIUM (SCHIZOGONY) ...... XXXV. EIMERIA (COCCIDIUlt) AVIUM (MACROGAMETE FORMATION) .... XXXVI. EIUERIA (COCCIDIU1I) AVIUM (MICROGAMETES SPOROGONY) .... XXXVII. EIMERIA (COCCIDIUM) AVIUM (SPOHOGONY) ....... TEXT-FIG. 1. DIAGRAM OF LIFE-CYCLE OF SIMERIA (COCCIDIUM) AVIUM XXXVIII. AVIAN COCCIDIOSIS ......... XXXIX. (1) APPARATUS FOR MAKING CULTURES AND (2) ALIMENTARY CANAL OF GROUSE . XL. TEST TUBES CONTAINING T. PERGRACILIS (2 Figures) . . . . . XII. SECTIONS OF CAECUM SHOWING T. PERGRACILIS (6 Figures) . . . . XLII. T. PERGRACILIS and D. UROGALLI (4 Figures) ...... XLIII. SECTIONS OF CAECUM (6 Figures) ........ XLIV. DIAGRAM OF ALIMENTARY CANAL SHOWING HABITATS OF INTESTINAL PARASITES XLV. BLOOD CELLS OF BIRDS CHIEFLY OF GROUSE ...... XLVI. LBUCOCYTOZOb'N LOVATI ......... XLVII. LEUCOCYTOZOON LOVATI, SPIROCH/ETA LAGOPODIS AND HsEMOPROTEUS MANSOKI XLVIII. TRICHOMONAS EBERTHI, SPIROCH.KTA LOVATI, AM(EBA LABOl'ODIS XLIX. DAVAINEA VROOALLI ........ L. D. UROGALLI AND HYMEKOLEPIS MICROPS ...... LI. D. UROGALLI, HYMENOLEPIS MICROPS, ETC. (7 Figures) ..... LII. HYMENOLEPIS MICROPS . . . . . . . ... LIU. GONIODES TETRAONIS (4 Figures) ........ LIV. KIRMUS CAMERATUS (2 Figures) ........ LV. ORNITHOMYIA LAGOPODIS (3 Figures) ... LVI. CERATOPHYLLUS GALI.INULJE, ETC. (3 Figures) ...... LVII. HEATHER GROWING FROM THE ROOT AND FROM SEED .... LVIII. THE HEATHER BEETLE (LOCBMJEA SUTVRAUS) (4 Figures) to / nee page > paye Page 159 160 162 163 164 170 209 219 221 221 223 225 227 227 to face page 238 240 243 245 248 252 278 283 285 287 288 290 309 319 320 326 335 336 337 342 350 357 358 361 401 426 page to face page INTRODUCTION By Lord Lovat BEFORE the formal appointment of the Committee in 1905 the following preliminary work of organisation was carried out. On June 5th, 1904, the organisers of the present investigation met, and after discussion formed a Committee of Inquiry to investigate the subject of " Grouse Disease." The following gentlemen were present : The Marquis of Tullibardine, Lord Lovat, Mackintosh of Mackintosh, Mr R. H. Rimington Wilson, Mr J. Graham, Mr D. W. Drummond, Mr R. C. Munro Ferguson. Lord Lovat was appointed Chairman, and Lord Onslow, the then President of the Board of Agriculture, was approached with the view of obtaining the assistance of that Board. A further meeting was held in December of the same year, when the details of the proposed lines of inquiry were discussed, a Secretary was appointed, and a number of witnesses were examined. The formal appointment of the Committee as a Departmental Committee of the Board of Agriculture and Fisheries was intimated by the Secretary of the Department on April 13th, 1905. The terms of the appointment marked a departure from the usual procedure in such matters, for they provided that no public funds should be devoted to the Inquiry, but that the investigation should be conducted at the expense either of the members of the Committee or of private subscribers. The members included the above-named gentlemen, with the addition of Earl de Grey (now Marquis of Ripon) and Lord Henry Scott. Dr William Somerville was appointed to represent the Board of Agriculture and Fisheries, and upon his retirement from the Board Mr T. H. Middleton was appointed. The Committee sustained a severe loss by the death in 1910 of Mr James Graham, one of its most active and capable members. In April and May 1905 an appeal was sent to a limited number of proprietors and tenants of Grouse moors asking for financial support. This appeal resulted in subscriptions amounting to over 400 ; these subscriptions were limited to a sum xi xii INTRODUCTION not exceeding 5 a year, and in the majority of cases were guaranteed for a period of three years. On the strength of this response a number of scientific gentlemen were asked to assist in the investigation, and a body of local corre- pondents in different parts of the country was appointed to make observations and to report upon any special local conditions or circumstances affecting Grouse in their respective districts. These local correspondents consisted mainly of resident proprietors, factors, estate agents, and gamekeepers. Great care was taken in their selection, and experience has shown that they have fully justified their appointment. About three hundred correspondents were formally appointed, and many other proprietors and gamekeepers corresponded regularly with the Secretary and with the staff of the Committee whenever occasion arose. The list of local correspondents might easily have been doubled by adding to it the names of those who had shown themselves able and willing to assist the investigation, but unfortunately the funds of the Committee would not admit of such addition. Lists of the Committee, of the staff, and of the local correspondents are given in Appendix A. For the instruction of local correspondents and others who wished to be informed of the existing state of knowledge on the subject of " Grouse Disease," and further to indicate the exact points upon which information was required, the Committee drew up an illustrated pamphlet entitled " Notes on the Grouse " ; in this a short summary was given of the life history of the bird, with a description of the typical characteristics of " Grouse Disease " as then recognised. The pamphlet called attention to the many theories which existed on the subject, and indicated the lines upon which the Committee proposed to carry out their investigation. This pamphlet was privately circulated among correspondents and subscribers, but was not offered for sale. The scientific experts drew attention to the difficulty of carrying out experiments upon Grouse in a wild state, and accordingly in 1906 the Committee established an observation area in Surrey, where it was soon demonstrated that Grouse could be kept in captivity. The necessary licence was obtained from the Home Office. This observation area has been of the utmost value to the Committee. Owing to the necessity of having a constant supply of healthy Grouse for examination in every month of the year, to enable the Committee to collect accurate information on the question of feeding, moulting, and seasonal changes, arrangements were made by members of the Committee and certain local corre- spondents to send to the Field Observer each month of the year a certain number of freshly killed birds. Many hundreds of such birds have been examined, and INTRODUCTION xiii from the material so obtained valuable, and in many cases new information was gained. An interesting collection of over six hundred Grouse skins has been prepared, showing the types of plumage found in both sexes at different times of the year and in different districts, and also certain abnormalities. Selections from this collection and from the other material collected by the Committee were exhibited at a soiree of the Royal Society irTMay 1909, and at the Vienna Sports Exhibition of 1910. The Committee began their observations in the field in the autumn of 1905 ; during this season and 1906 the stock of Grouse both in Scotland and England was remarkably healthy, and an excellent opportunity was thus given to study the bird under normal conditions. The Field Observer visited many moors, his visits extending over a period of seven months, from April to October. During this time he got into close touch with the Committee's correspondents in different parts of the country, checked their information, and with their assistance studied the varying conditions governing particular districts. Whenever a case of suspected " Grouse Disease " was reported the moor was visited by the Field Observer or one of his assistants, and specimens of suspicious birds were subjected to laboratory examination. During 1907 a considerable mortality amongst the Grouse in certain districts was reported in the spring and early summer months. The Committee's experts made a very careful investigation into every case reported, but, contrary to expectation, it was not found that the character of the disease differed materially in its essential features from those occasional isolated cases of mortality which had occurred in the previous year. The Committee found no examples of the acute or sudden form of disease which had been described by former observers. The out- break of mortality, however, gave an excellent opportunity for collecting data regarding the lingering or pining form of disease which has since been traced to the ravages of the threadworm Trichostrongylus pergracilis? By 1908 the Committee had completed the preliminary work required to enable the subject to be developed on scientific lines. Evidence and statistics had been collected which indicated the special directions in which further investigations were necessary or likely to be helpful. The natural history of the normal healthy Grouse had been fully studied, and the general pathological characteristics of " Grouse 1 In the following chapters this worm is usually called Trichostrongylus pergracilis, but some writers have preserved Strongylus i>ircjracilis, it is also at times called the Strongyle or the Strongyle worm. A synonym and a list of allied species are given by Dr Shipley on pp. 207 et seq. xiv INTRODUCTION Disease," from a field observer's point of view, had been ascertained. Even at this date the Committee were of opinion that they had discovered the principal causes of mortality amongst Grouse ; but until they had further confirmed their suspicions they decided not to publish anything in the nature of results. It was at this stage that an impatient public and the necessity to stimulate dilatory subscribers forced upon the Committee the necessity of publishing some account of their progress, and the Interim Report issued in August 1908 was the outcome of this demand. The Interim Report contained an account of the work done by the Committee up to date, but omitted all reference to the results which had only been achieved in part. During the second or research stage of the investigation the following special points were studied: (1) The life history of the Trichostrongylus pergracilis, which the Committee believed to.be the immediate cause of " Grouse Disease "; (2) The life history of the other internal parasites of Grouse ; (3) The protozoal parasites infecting the alimentary tract and blood of Grouse ; (4) The bacteriology of Grouse ; (5) The various insects found on the moors both from the point of view of insect-borne disease and from the point of view of food ; (6) The questions affecting the food supply of Grouse, including the management of heather land, causes of destruction of heather, e.g., frost, heather-beetle, etc. These lines of research were diligently followed up by the members of the Committee's Scientific Staff during the last three years of the Inquiry the work entailed long series of experiments carried out upon the open moor, in the labora- tory, or at the Frimley observation area. The results have been unexpectedly conclusive, considering the short time available for so great a task. The Committee consider that although their immediate object has been achieved, viz., the elucidation of the causes of "Grouse Disease," the present Inquiry has scarcely crossed the threshold of the investigation into the general pathology of birds, and there is still a large amount of work which might be profitably under- taken. The most important department of the research, so far at least as relates to mortality amongst adult Grouse, was the investigation of the life history of the strongyle threadworm. The work was rendered difficult owing to the small size of this parasite, but thanks to the efforts of Dr Wilson, Dr Shipley, and Dr Leiper, we are now in a position to speak with something approaching certainty on the subject. These gentlemen have worked at the subject for more than three years, and have not only ascertained the life cycle through which this worm passes, but have discovered the conditions which are favourable or preju- INTRODUCTION xv dicial to its growth ; they have been able to rear the young strongyle, and by administering it through the medium of food to hand-reared Grouse free from nematode infection, have infected the hand-reared birds with " Grouse Disease." Another interesting and important outcome of the Inquiry has been the discovery of a cause of death among Grouse in their infancy due to the presence of an intestinal parasite known as Eimeria (Coccidium) avium. It is unfortunate that the Inquiry is being brought to a close while Dr Fantham is still engaged in tracing the predisposing causes of this disease with a view to finding whether any preventive measures are possible. It is true that such preventive measures, even when found, might not be easily applied to the Grouse in a wild state ; but they would be of the greatest possible value for the treatment of hand-reared game-birds or domestic fowls. During the progress of the Inquiry many questions affecting Grouse and Grouse shooting, but not directly connected with disease, have come before the notice of the Committee, and owing to their general interest to readers of the Eeport it has been thought well to refer to some of them. Since the Inquiry has been mainly supported by those whose interests are more intimately connected with sport than with science, the inclusion of chapters on such subjects of practical importance as Moor Management, Heather-burning, Vermin, Keepers and the Value of Grouse moors, requires no apology. The chapters of natural history, such as Life History, Plumage changes, Food, Physiology and Death from Causes other than Disease, are all indirectly connected with the main subjects of the Inquiry. It will be seen that by the inclusion of the above-mentioned chapters the Report of the Committee becomes a monograph on the Red Grouse in health and disease rather than a summary of the proceedings of a Departmental Committee of Inquiry. During the period of the Inquiry a large number of Pamphlets, Reports, and Letters of Instructions have been printed and issued by the Committee to its local correspondents and other supporters. These documents, in addition to the " Notes on the Grouse " pamphlet already referred to, include Notes of Evidence taken at the meetings of Committee, Lists of Queries, Forms of Particulars of Specimens, Periodical Reports on the Progress of the Inquiry, Lists of Subscribers, Lists of Local Correspondents, Statements of Crop-contents, Circular Letters to Proprietors, etc., etc. In all more than 40,000 printed documents have been circulated, in addition to a large number of typewritten circulars and letters, of which no accurate record has been kept. The correspondence both of the Secretary and the Field Observer has been xvi INTRODUCTION voluminous, and has sometimes been subject to such sudden bursts of activity that it was found well-nigh impossible to keep pace with it. To this cause must be ascribed occasional failures to acknowledge written communications by return of post, for which failures the Committee now tender their apology. In the course of the investigation many technical questions arose which made it necessary to employ the services of leading scientific experts, and, owing to the difficulty in obtaining immediate and definite results, it was found that the period of the Inquiry would have to be extended beyond the three years originally fixed. The result has been that the Committee found it necessary to exceed their original estimates. During the whole Inquiry the Committee has been greatly hampered in their labours by lack of funds. The total income has never amounted to 1,000 in any one year, and the work would have been in danger of coming to an end were it not that many members of the Scientific Staff have given their services gratuit- ously or for at most a nominal consideration. What success the Committee have met with is due to several causes. Firstly, the work was, in the main, directed by small Sub-Committees who were unham- pered by official restrictions and untrammelled by traditional red tape. Secondly, the Chairman and the Secretary had the cordial support not only of the other members of the Committee but of all those directly or indirectly interested in the Grouse. Thirdly, the members of the Scientific Staff took the keenest interest in the problems they sought to solve, and were willing to place their knowledge, their spare time, and their technical skill at the disposal of the Committee unremunerated, or at best remunerated at an entirely inadequate scale. Fourthly, the Inquiry aroused a certain public spirit, which not only found expression in the willingness of sportsmen, landlords, keepers, and others to do all in their power to assist the work of the Committee, but led the printers, the firm which supplied the paper upon which the book is printed, the publishers and many others connected with the preparation of the volume, to grant the Committee the most favourable terms. That this Inquiry did not cost more than the small sum of 4,366 in the six years over which the work extended (averaging 727 a year) is due to the causes set forth above, and to the constant vigilance and unselfish insistance on economy on the part of the Secretary. Compared with the cost of similar Royal Commissions and Departmental Committees this sum is a mere trifle, but it shows that satisfactory results can be attained at very small expense. Much money was of course saved by not printing the evidence given at the numerous examinations of gamekeepers INTRODUCTION xvii and others held by the Committee. Such evidence is, as a rule, printed in full, and remains unheeded and unread in tons of neglected Blue-Books. Then again the money has been carefully and laboriously collected, for the Committee were precluded by the terms of their reference from drawing on the purse of the tax- payer. This also made for economy. Some criticisms have been heard at the delay which has occurred in the produc- tion of this volume. But it should be remembered that when the Inquiry started very little was accurately known about the Grouse either in health or in disease. As a member of the Scientific Staff said in a lecture before the Royal Institution : " In considering exceptions it is so immensely important to know the rule. In studying disease our starting-point should be the normal, the healthy ; yet until lately no one has closely studied the healthy Grouse, and indeed it is almost impossible to find a normal Grouse, i.e., one free from parasites. A Grouse cannot express to us its feelings ; the state of its tongue, the rate of its pulse, even its temperature tell us nothing because we have no norm and no means of estimating the extent to which a diseased Grouse has departed from the standards of a healthy bird. The nature of the numerous kinds of blood corpuscles, which alter in proportion so markedly in animals when they become parasitised, was but a few months ago quite unknown, the "blood count" uninvestigated ; in fact the Inquiry started, as regards the cause and symptoms of the diseases which affect Grouse, practically behind scratch." Further, the Committee were not in a position to retain the whole time of any one of their Scientific Staff with the single exception of the Field Observer. What work this staff have accomplished, and they have accomplished much, has been for the most part done in their spare time or during their brief holidays. Another factor that made for delay was that the Committee were not in a position to establish a central laboratory, and hence the actual investigations were carried on for a time in one place, and then after a break often of many weeks the threads were picked up in another. Much work was done at Cambridge, but at the London School of Tropical Medicine, at the Royal Scottish Museum, Edinburgh, at Frimley, at King's School in the Isle of Man, in the offices of the Field in London, in the gun-room at Beaufort, valuable investigations were also carried on. Further, from the necessity of examining absolutely fresh material, an improvised travelling laboratory had to be set up perhaps in a private sitting-room of a country hotel, perhaps in an outhouse of a Highland inn, but always under conditions which vastly increased the difficulty of investigation, and made for delay. xviii INTRODUCTION Considering all these circumstances, the results now published do not seem unduly belated. The Committee specially desire to record their thanks to the following gentle- men who have formed the Scientific Staff of the Inquiry, and to whose labours the results are due : EDWARD A. WILSON, M.B., F.Z.S., M.B.O.U., was appointed, in November 1905, principal Field Observer, Anatomist and Physiologist to the Inquiry, and devoted his whole time to the work till the autumn of 1910, when he joined Captain Scott's Antarctic Expedition as Scientific Director on the Terra Nova. It is difficult to speak highly enough of Dr. Wilson's services, for not only was he an indefatigable worker in the field, but his ornithological knowledge, his scientific training, and his artistic skill, have been of the utmost value in every branch of the Inquiry. Practically every Grouse which was submitted to the Committee for examination was dissected and reported on by Dr Wilson, and the results of these dissections, as shown in Appendix D, not only form a record of long and patient labour, but also provide an enormous mass of carefully arranged material which has been of great use to the Committee. Dr Wilson has written or aided in writing ten out of the first fourteen chapters of the Book, and has not only fully illustrated his own contributions, but has placed his artistic skill at the disposal of nearly all the other writers. In addition to his services as Field Observer and Physiologist, Dr Wilson conducted a series of experiments on live Grouse at the Committee's Observation Area whereby the results obtained by Dr Leiper, Dr Shipley and others were put to the test ; these experiments entailed some years of hard and patient work, and required the closest co-operation with the other members of the Scientific Staff. Dr Wilson's personal qualities secured for him the willing assistance alike of Local Correspondents and Scientific Staff, and went far to ensure whatever success the Committee has achieved. A. E. SHIPLEY, M.A., Hon. D.Sc., F.R.S., Master of Christ's College, Cam- bridge, and Reader in Zoology in the University of Cambridge, undertook in June 1905 to assist the Committee in the Scientific Departments of their research, especially in connection with the investigations of the ectoparasites and endoparasites of Grouse. Dr Shipley's services to the scientific side of the Inquiry have been as important as Dr Wilson's services to the natural history side. Dr INTRODUCTION xix Shipley has published the results of his labours in the Proceedings of the Zoological Society of London for 1909 in the following series of articles : (1) The Tapeworms (cestoda) of the Red Grouse ; (2) The Threadworms (nematoda) of the Red Grouse ; (3) The ectoparasites of the Red Grouse ; (4) The Internal Parasites of birds allied to the Grouse. The first three of these papers are, by the courtesy of the Zoological Society of London, reprinted with minor, alterations in the present Report. Dr Shipley has also acted as one of the Publishing Sub-Committee of the Inquiry, and has given much assistance in the revisal of the proofs and the preparation of Interim and Final Reports for the press. R. F. LEIPER, D.Sc., M.B., F.Z.S., Helminthologist to the London School of Tropical Medicine, was appointed in 1908 to help in the elucidation of certain difficult questions relating to the life history of the nematode worm Tricliostrongylus pergracilis, which in the opinion of the Committee is the main cause of mortality in adult Grouse. Dr Leiper devoted much time to the study of these questions, and to him is due the credit of having solved many of the problems connected with the development and bionomics of this important parasite. The result of his investiga- tions are given in the present Report. W. BYGRAVE and PERCY H. GRIMSHAW assisted Dr Shipley by a prolonged and systematic search for the intermediate host of the Grouse tapeworms, and though the results were negative, the conscientious manner in which the search was conducted has enabled the Committee to claim that the question has been investigated as fully as was possible in the time at their disposal. H. B. FANTHAM, D.Sc. Lond, B.A. Cantab., A.R.C.S., F.Z.S., Christ's College, Cambridge, Parasitologist to the Liverpool School of Tropical Medicine, formerly Assistant to the Quick Professor of Biology in the University of Cambridge, was appointed Protozoologist to the Inquiry in 1907, and since that date has made a careful study of the protozoal parasites which are found in the blood and alimentary tract of the Grouse. His researches have resulted in a most interest- ing series of discoveries, of which by far the most important from the Committee's point of view is that the Eimeria (Coccidium) avium frequently found in the alimentary tract of the Grouse is a frequent cause of death of young birds. Dr Fantham has followed up and fully described the life history of this parasite, whose presence in the intestine of the young Grouse was first pointed out by Dr. Leiper, and has published the results of his researches in the Proceedings of the Zoological Society of London for October 1910 in the following series of articles: (1) The xx INTRODUCTION Morphology and Life History of Eimeria ( Coccidium) avium : a Sporozocin causing a fatal disease among young Grouse ; (2) Observations on the Parasitic Protozoa of the Red Grouse (Layopus scoticus) ; (3) Experimental studies on Avian Coccidiosis, especially in relation to young Grouse, Fowls and Pigeons ; (4) Observa- tions on the Blood of Grouse. By the courtesy of the Zoological Society of London these articles are reprinted in the present Report. C. G. SELIGMANN, M.B., then Pathologist to the Zoological Society of London, was appointed in 1906 to investigate the bacteriology of "Grouse Disease." He worked for the Committee till the end of 1907, when he left for Ceylon on a scientific expedition. The Committee is indebted to him for the discovery that the bacterial characters observed by Professor Klein as symptomatic of "Grouse Disease " were not in fact the pathological accompaniment of the mortality in Grouse as observed by the Committee. After Dr Seligmann went abroad his observations on this point were continued and confirmed by Dr Cobbett and Dr Graham Smith. L. COBBETT, M.D., F.R.C.S., University Lecturer in Pathology, Cambridge, and G. S. GRAHAM-SMITH, M.D., University Lecturer in Hygiene, Cambridge, consented in 1909 to continue the work where Dr Seligmann had left off. They made an exhaustive investigation of the general pathology of "Grouse Disease" in all its forms, and the relation of the Bacillus coli of Professor Klein's " Grouse Disease " to the various pathological lesions which had come under the observation of the Committee. The results of their investigations were published in the Journal of Hyyiene in June 1910, and, by the courtesy of Professor Nuttall, the Editor of that Journal, arc reprinted in the present Report. L. W. SAM BON, M.D., gave considerable assistance to Dr Seligmann during the spring of 1907, and discovered a new leucocytozoon in the blood (L. Lovati). H. HAMMOND SMITH, M.B., Pathologist to the Field newspaper, has assisted the Committee both in the field and in the laboratory since the Inquiry was commenced. He established and organised the Observation Area at Frimley iu Surrey, and gave great assistance to the Committee in connection with the conduct of experiments at this Observation Area. He also assisted in the study of the question of the grits found in the gizzards of the Grouse and other game birds, and gave great help to the Committee in connection with the conduct of experiments at the Observation Area. INTRODUCTION xxi R. H. RASTALL, M.A., F.G.S., Fellow and Lecturer of Christ's College, Cambridge, drew up an interesting report on the mineral constituents of gizzard grits in Grouse, and gave assistance in writing the article dealing with grits which appears in this Report. He also aided the work of publication by reading and correcting almost the whole of the proofs of this Report. PERCY H. GRIMSHAW, F.R.S.E., F.E.S., Assistant Keeper of the Natural History Department, Royal Scottish Museum, was appointed in 1909 to undertake the whole investigation of the insect life on the moors. He carried on and elaborated the work begun by Mr Fryer and Mr Hill, and not only prepared a complete list of the insects found on the moors, but also reported upon those eaten by the Grouse as shown by an examination of their crops and gizzards. The result of his work is published in the " Annals of Scottish Natural History" for July 1910, and in chapter iv. and Appendix E of the present Report. Mr Grimshaw also undertook the investigation of the habits and life history of the heather beetle (Loehmcea suturalis), and his article on this subject is included in the Report. GEORGE C. MUIRHEAD, B.Sc., acted as Field Observer from May to December 1905, and assisted in drawing up the pamphlet " Notes on the Grouse." J. C. FRYER, B.A., Gonville and Caius College, Cambridge, was appointed in 1907 to make a report on the Insect Life of Grouse Moors. This Report has already appeared in the Interim Report of the Committee. ALFRED HILL was employed in 1908 to carry on the investigations already commenced by Mr Fryer. A. S. LESLIE, B.A., W.S. As soon as the Committee was officially appointed in 1905, one of their first acts was to nominate Mr Leslie as Secretary. During the six years that the Committee have sat he has continued to act in that capacity, and his duties have been both varied and arduous. To him was entrusted the task of collecting the subscriptions, which formed the sole source of income for the Inquiry, and without which nothing could be done ; the control of this Fund further rested in him. He also got together and organised the three hundred and sixty local correspondents, he drew up all the various tables, forms, etc., with which these correspondents were supplied, received the answers to the questions asked, collated and tabulated not only these answers but the verbal xxii INTRODUCTION replies given at the several examinations of gamekeepers and other experts, which from time to time the Committee held. His correspondence amounted to many thousands of letters. Further, he assisted the Field Observer in many ways, especially in the preparation of statistics and the arrangement of tabular matter. Mr Leslie wrote the "Notes on the Grouse," and has been in the main responsible for the preparation and seeing through the press both the Interim and the present (Final) Report ; the compiling of the appendices and the index, and the revision of the proofs, were largely his work. To his knowledge of Scotland and of sport, and his professional training, the Committee owe many valuable suggestions as to the course the investigations have from time to time taken. They feel they cannot speak too highly of the self- sacrificing way he has thrown himself into the work, of his untiring energy, of his powers of organisation or of his adaptability and tact, which has done much to make the labours of not only the Committee but of all in any way associated with the Inquiry not only profitable but pleasurable. The salary that the Committee have been able to offer to Mr Leslie can only be described as derisory. He has, in fact, received but the scantiest payment for the work he has done, and no compensation of any kind for the time he has taken from his profession and given to the Inquiry. But not only has he, like others, given time, skill and knowledge to further the cause of the investigation, but by his skilful husbandry of the limited resources available he has enabled the Com- mittee to cover a wider area of research, and to prolong the time during which research was carried on to an extent which at first seemed impossible. R. B. FRASER was appointed Assistant Secretary in October 1907, when it was found that the work of organisation and correspondence could not be conducted single handed by the Secretary. Mr Fraser has given valuable assistance with the general secretarial work, and also with the additional work entailed in con- nection with the preparation of the Report for the press. In addition to those already mentioned the following have given the Committee much assistance in the revisal of proofs and in other ways: W. BERRY, B.A., LL.B., M.B.O.U., who has been chiefly responsible for the Index ; W. R. OGILVIE GRANT, M.B.O.U., of the British Museum of Natural History; W. EAGLE CLARK, F.L.S., F.R.S.E., etc., Keeper of the Natural History Department of the Royal Scottish Museum; L. R. SUTHERLAND, M.B., Professor of Pathology in the INTRODUCTION XXlll University of St Andrews ; Mrs E. A. WILSON, and the Hon. GLADYS GRAHAM MURRAY, F.Z.S. An Abstract of Accounts is annexed, from which it may be seen how the income has been expended. 1 The whole funds have now been exhausted in the work of investigation, and there is no balance available to meet the cost of publishing the results. This is to be regretted, as it will make it impossible to provide the supporters of the Inquiry with copies of the Report free of charge. The thanks of the Committee are due to those moor-owners, shooting tenants, gamekeepers, and others who have gratuitously given their services as corre- spondents. The Committee have to acknowledge with thanks the support it has received from its subscribers. A list of subscribers and the amount of their subscriptions is given in Appendix B. 2 The Committee have also to acknowledge their indebtedness to the Zoological Society of London, which at the request of the Committee published in the Pro- ceedings of the Society the articles on Ectoparasites and Endoparasites of Grouse by Dr A. E. Shipley ; the articles on the Protozoa and Blood of Grouse, by Dr H. B. Fantham ; and the article on the Plumage of Grouse, by Dr E. A. Wilson, comprising an important part of the scientific matter contained in this volume, which is reproduced here by consent of the Society. They have also to acknowledge their indebtedness to the Society for revising and editing the manu- script of Dr Wilson's contributions on the Plumage of the Grouse, in the absence of the author on the Antarctic Expedition. The Committee also desire to acknowledge its indebtedness to the heads of the various Scientific Laboratories at Cambridge, where much of the research work was carried on ; to the London School of Tropical Medicine who permitted Dr Lei per to assist in the investigation ; and to the Directors and Staff of the Royal Scottish Museum, who assisted the Committee in various ways during the whole period of the Inquiry. 1 Vide vol. ii., Appendix C. 2 Vide vol. ii., Appendix B. August 1911. THE GROUSE IN HEALTH AND IN DISEASE PART I. THE NORMAL GROUSE CHAPTER I THE SYSTEMATIC POSITION OF THE GROUSE By A. H. Evans THE name Grouse, in the form " Grows," has been traced back by Salusbury Brereton to the reign of Henry VIII. (1531), and in its present form to 1603. But, since it first occurs in an ordinance for the regulation of the Royal Household at Eltham in Kent, it ought in all probability to be applied the name to the Black Grouse which may then have inhabited that county, though no actual record has yet been discovered. Further particulars are given by Professor Newton in his " Dictionary of Birds." l The-appeilation has, however, by universal consent been long "transferred to the Red Grouse, the Moorfowl of our forefathers , and when standing alone would never now be understood otherwise. This species is the most characteristic bird of the Scottish moorlands, including the Hebrides and the Orkneys, and is plentiful thence to the northern counties of England ; in few places is it more numerous than on the Dj 8tr jb u . moors of South Yorkshire and Derbyshire in the vicinity of Sheffield ; tion - while to the west it not only occurs in decreasing numbers to Shropshire, but is found in Wales as far south as Glamorganshire, and in Ireland in most suitable localities. Attempts have been made to acclimatise it to the north and south of its proper range ; but the few pairs turned down in Acc i imati . Shetland between 1858 and 1883, with a greater number in 1901, sation - have never thriven, while their descendants are apparently extinct, and the same may be said of those introduced into Surrey, Norfolk, and elsewhere, with 1 A. Newton, "Dictionary of Birds," p. 388. London : A. and C. Black, 1893-1896. VOL. I. 1 A 2 THE GROUSE IN HEALTH AND IN DISEASE three exceptions. The first instance is that noticed by Professor Newton in his "Dictionary of Birds," 1 when Baron Dickson succeeded in acclimatising the species near Gottenburg in Sweden ; the second is that of its introduction in 1893-1894 to the Hohe Venn, a high tract of moorland on the borders of Belgium and Germany, south of Spa, where Red Grouse are still thriving ; and the third the successful experiment on Lord Iveagh's property at Icklingham in Suffolk in 1903, where the birds, despite the necessity of an artificial water supply on the dry, sandy heaths, had increased in 1909, and appeared likely in 1910 to form a permanent colony. In the Hohe Venn district after two failures fifty pairs or more were liberated in August 1894, and by 1901 had increased to about a thousand head in spite of regular shooting. Professor Somerville of Oxford, who has kindly furnished particulars, saw the birds there in September 1910. During the last twenty years it has been strongly borne in upon the general public, as well as sportsmen, that the welfare of the Grouse is an affair of national interest ; for game of every description is becoming less and less a Economic - importance luxury of the rich, and more and more a regular factor of our food supply, facts which cannot be ignored by the modern economist, and are now considered to be well within the province of the Government, which has at last consented to bestir itself in the matter. Here I propose to give a brief account of the position of the Red Grouse in the class of birds. In nearly all linear systems of classification put forward ciassiflca- ^7 mo( lern systematists, whether they start from the highest or from tlon - the lowest forms of creation, the large order Galliformes or its equivalent stands about midway in the carinate or keel-breasted birds, being connected most closely on the one hand with the Falconiformes and Anseriformes, on the other with the Gruiformes and Charadrii.formes. Its position is thus well ascertained, and no serious doubts have been raised as to its constituent members, except that the Tinamidse (Tinamous) of South America, which have been sometimes included in it, are now by pretty general consent placed next to the Ratite birds, with keelless breastbone. Under the order Galliformes may be placed in suborders the curious Mesites of Madagascar, the no less peculiar Opisthocomus or Hoatzin of northern South America, and the Old World Turnices (Button Quails) with their close ally Pedionomus ; but the only suborder with which we are here concerned is that known by the name of Galli. Under the Galli, again, we need only make 1 " Dictionary of Birds," p. 389. THE SYSTEMATIC POSITION OF THE GROUSE 3 passing reference to the group called by Huxley, Peristeropodes, where the toes are all in one plane ; this includes the families Megapodiidae or Mound-Builders of the eastern tropics, and the Cracidse or Curassows of the neotropical countries. Huxley's second group, the Alectoropodes, with an elevated hind toe, is equivalent to the family Phasianidse, which may be subdivided into the subfamilies Numidinse, or Guinea-fowls, of Africa, the Meleagrinse, or Turkeys, of America, the Odontophorinse, or " American Partridges," the Phasianinse, or Pheasant, Partridge, and Fowl alliance of the Old World, and the Tetraoninse, or Grouse. The last-named might well be classed as a separate family Tetraonidse, were it not for the great difficulty of placing correctly such forms as Caccabis (Red-legged Partridge), Francolinus (Francolin), and Coturnix (Quail), which are so nearly allied to both Partridges and Grouse that we may ven doubt the advisability of allowing a separate subfamily Tetraoninse at all. Grouse, as thus limited, are entirely confined to the Holarctic region, the great majority of the species being inhabitants of the New World, though a fair number, including the fine Capercailzie, the Black Grouse and Dj str Ub U .. the Hazel Grouse, are to be found in various parts of the Old World. tlon- The Red Grouse of Britain belongs to Lagopus, the only genus of Grouse common to both hemispheres, in which even the digits are feathered. This -contains six well-defined species : the Spitsbergen Ptarmigan (L. hemileucurus) .and the Rocky Mountain Ptarmigan (L. leucurus) only found in the regions after which they are named the Ptarmigan of Scotland and the mountains of the Palsearctic area (L. mutus), the " Iceland " Ptarmigan of that island, Greenland and the lower grounds of Northern Siberia and Arctic America (L. rupestris), the Willow Grouse of the north of Europe, Asia, and America (L. albus), and the British bird (L. scoticus)with which alone we are concerned indigenous in no other country. All the forms of the genus Lagopus are anatomically identical, but the Red Grouse differs from the remaining members in that it does not turn white in winter. It has been thought to be merely the local representative of the Willow Grouse in Britain, though it differs from that species even in its summer plumage, and never possesses white wing-quills. It varies con- siderably in coloration, as will be seen from the following quotation from " The Cambridge Natural History." "The male in both summer and winter is more or less chestnut-brown above, with black markings and a reddish head ; the lower parts are similar, but are usually spotted with white. In autumn the brown of 4 THE GROUSE IN HEALTH AND IN DISEASE the upper parts becomes buff, and the lower surface is barred with buff and black. Mr Ogilvie-Grant recognises three types of plumage in the male, a red form with no white spots, from Ireland and Western Scotland ; a blackish variety comparatively rarely found ; and another largely spotted with white below or even above. Intermediate specimens constitute the bulk of our birds. The female exhibits, moreover, a buff-spotted and a buff- barred form ; but in summer she is typically black above with concentric buff markings, and buff below with black bars. Her autumn plumage, which continues throughout the winter, is black, spotted with buff and barred with rufous." J As we write, Mr Ogilvie-Grant has published in the "Bulletin of the British Ornithologists' Club " an elaborate account of the changes of plumage undergone by the Red Grouse, and of the points wherein he differs from Mr Millais and Dr Wilson ; but this is not the place to enter into controversial matters, and our readers must form their own opinions on the subject. 8 Various reasons have been suggested for the absence of a white winter plumage in the British bird, for which reference may be made to the late Professor Newton's "Dictionary of Birds." 4 The Red Grouse is not polygamous ; the birds pair very early in the year, and consequently breed at a time when the eggs are apt to be seriously damaged by late frosts, while the young often suffer from similar causes. The usual haunts are moors clothed with heather (Erica) and ling (Calluna), but in some parts at least of the north-west of England they are to be found on hills covered with crowberry (Empetrum), rush (Juncus), and other vegetation, where little if any heather or ling grows. As a rule, the nest is a slight structure of bents and so forth, placed in thick heather or grass, or even on almost bare ground ; the eggs, ranging from five or six to more than a dozen in number, have a yellowish or buffish white ground-colour, normally blotched and spotted with reddish or blackish brown. The colour of the markings, however, varies considerably ; in some specimens they are purplish or very rich red, in others orange-red. The eggs measure nearly 2 inches by rather more than 1. The cock utters his well-known crow at all seasons ; the hen has a somewhat different note in the mating season, and when in charge of the young. The cock has also a clear ringing cry. The general habits will be dealt with in the later chapters. 1 " Cambridge Natural History," vol. ix., Birds, p. 338. Cambridge, 1899. 2 " British Ornithologist's Club," vol. xxii. p. 122. London, 1910. ' Vide also chap. iii. 4 " Dictionary of Birds," p. 391. CHAPTER II THE LIFE HISTORY OF THE GROUSE By A. S. Leslie No precise date can be given at which Grouse begin to pair, for this depends more upon the climatic conditions than upon anything else. In a mild winter Grouse will pair as early as December or January ; but if, after they are paired, the weather becomes rough and stormy they will again congregate in packs, even after the usual date of nesting has arrived. The time at which they select their nesting ground (March and April) is also, to a limited extent, influenced by climatic conditions. On high moors, where the snow lies in late seasons till far into the spring, it some- p airing times happens that during the whole winter, and even up to the month of April, there is hardly a bird upon the hill, the whole stock being congregated on the lower - lying moors where there is " black ground" ou which food can be obtained. In such seasons it is interesting to observe the return of the stock to the higher parts as soon as the snow begins to melt. As a rule the birds do not pair upon the low ground, but congregate in packs upon the edge of the snow, waiting for an opportunity of returning to breed on their native hill. A good example of this was furnished in the spring of 1908 on a high-lying moor in Inverness-shire. During the preceding winter there had been a heavy fall of snow which lay for many months on the higher ranges, and drove the Grouse down in vast numbers to the lower levels. On the moor referred to there was not a Grouse to be seen until the snow began to melt about the end of April. But at the first sign of thaw the stock began to return, and as each patch of bare ground came into sight a pair of birds arrived as if guided by instinct and commenced to nest. This year the shooting season turned out to be a record one, for upwards of 5 6 THE GROUSE IN HEALTH AND IN DISEASE five thousand brace were killed upon an area of 20.000 acres, and many more might have been shot without unduly reducing the stock. While heavy snow during the winter may do little harm though it lies till far into the spring, a loss of stock may result where the fall occurs after the birds have returned to their nesting ground on the higher ranges. This snow on occurred on a moor in Ross-shire in the year 1909, when a corre- spondent of the Committee reports as follows : " A heavy snowfall on April 24th put all the birds down to ' black ground.' They never went back to nest, and consequently the high ground, i.e., over 500 ft., was a failure, and the low ground better than usual." Again, a correspondent in West Perthshire writes : " In spring, when the breeding season is approaching a heavy snowstorm of some duration has on several occasions caused a most serious loss of stock, amounting to as much as half or more of the whole number of birds. After such a spring snowstorm and migration, large numbers of Grouse undoubtedly remain to breed on low and favourable moors within, say, ten or fifteen miles. These low moors are very heavily shot every year, but there is a constant migration of Grouse to them, both from overstocked moors, and from the high moors affected by snow." This is corroborated by a corre- spondent in the south of Scotland, who says : " I have an idea that if birds are forced to leave their usual ground (in spring), through deep untrodden snow, a good number may remain away and not return to their former ground." The subject of migration is more fully dealt with in another chapter. 1 During the mating season the pugnacity of the cock Grouse is well known, and in captivity the cocks have to be kept separate at this period, or disaster Pugnacity w ^ certainly occur. Under natural conditions the fights seldom of cocks. en( j fa^iy . k u t fc i s certain that the presence of a quarrelsome cock- bird in search of a mate seriously interferes with the pairing of the other birds in the vicinity. Observation in the field goes to prove that old cocks are more pugnacious than young ones, and as they are less valuable for breed- ing purposes the object of every moor-owner is to reduce the number of old cocks by every means in his power. The nest, a slight hollow scratched in the ground and lined with a scanty layer of grass, heather, etc., is usually placed on the sunny side of a tuft of heather, and preference as regards its site seems to be given to an area on which the heather is moderately well grown rather than where it is 1 See chap. xxiv. THE LIFE HISTORY OF THE GROUSE 7 rank. Birds will always nest in a place where they can see all round, if possible, hence their avoidance of long heather. 1 Nesting. Dry ground is always preferred ; birds will not nest on boggy or damp ground, and are more likely to leave their nests on account of wet than for any other reason. On some moors where the heather has been very closely burnt or the stock is unusually large, the Grouse appear to be unable to find nesting ground exactly suited to their requirements, and on these occasions they will boldly depart from their usual habits and will nest in short heather, flat dead bracken,, or even on a bare unsheltered piece of burnt ground, leaving the nest as open as that of the Lapwing. It is important to note that in all cases open sites devoid of all covering are preferred to really long overgrown heather. The time of nesting varies according to the season and the latitude. As a rule, most of the eggs are laid by the latter end of April and the beginning of May ; but a case has been reported of eggs being found as early as Time of March 28th, and the Rev. W. B. Daniel records that " on the 5th of hatohin g- March, 1794, the Gamekeeper of Mr Lister (now Lord Ribblesdale), of Gisburne Park, discovered on the Manor of Twitten, near Pendle Hill, a brood of Red Grouse seemingly about ten days old, which could fly about as many yards at a time. This was an occurrence never known to have happened before so early in the year." Macdonald states that the hen begins to lay at the end of March, 3 while Macpherson, writing in the Fur and Feather Series, says that " In the Island of Skye April 24th is a decidedly early date for a full clutch of Grouse eggs." 4 It is an interesting fact that, from the evidence obtained from many moors, of varying altitudes ranging from the south of Wales to the north of Sutherland, there is a difference of only two or three days in the dates when the earliest eggs are found ; March 30th in Yorkshire and Perthshire, and April 1st on high moors in Inverness and Sutherland are dates frequently recorded for the first nest. The date at which the first clutch is completed varies by a full fortnight on high and low ground and on north 1 Macdonald in " Grouse Disease " makes the following statement : " The happiest condition in which a nest can be found is in growing heather of about a foot in length, and in the immediate proximity of short young heather." (Macdonald, " Grouse Disease," p. 23. London : W. H. Allen & Co., Ltd., 1883.) And in another place he writes : " Grouse never nest amongst old, rough heather, always in a little tuft at the side or among the bent." (Ibid., p 26). Macpherson in the Fur and Feather Series, states that " It is a fallacy to suppose that Grouse like to nest in very old heather." (Fur and Feather Series, " The Grouse," p. 22. London : Longmans, Green & Co., 1894.) 2 Daniel, "Rural Sports," vol. iii. p. 108. London : Longmans, 1812. 3 "Grouse Disease," p. 99. 4 Fur and Feather Series, "The Grouse," p. 21. 8 THE GROUSE IN HEALTH AND IN DISEASE country and south country moors. In Yorkshire by the end of April many birds have begun to sit, while in central Scotland from April 25th to May 20th would probably cover the dates by which the full clutches are complete on most moors. The intervals between the laying of each egg vary enormously in captivity, probably also in nature, depending upon the weather ; for intervals example, at the Committee's observation area in Surrey it was noted of laying, ^at one hen took twenty-nine days to lay ten eggs an average of one egg every three days ; another laid only four eggs in twenty-six days, or an average of one egg every six and a half days. The clutch averages from seven to ten, and rarely reaches twelve. Macdonald states that the hen lays eight to fourteen or sixteen eggs, 1 while Macpherson gives seven and eight as the most usual number of eggs, and states that Number " more than ten is quite exceptional." 1 Seebohm, who speaks with f eggs, authority on all questions of British oology, states that the number of eggs laid would seem "to vary with the propitiousness or otherwise of the season. In very wet and cold springs the smallest clutches contain four or five, and the largest eight or nine ; whilst in very favourable seasons the small clutches are six or seven, and the larger ones from ten to twelve, or even fifteen and seventeen ; but in the latter cases it is probable that the eggs may not all be the produce of one bird. In an average year most nests will contain seven or eight eggs. Birds which breed late on the high grounds do not seem to lay fewer eggs than those which breed early in the more sheltered situations." ' A correspondent of the Committee in Forfarshire has reported a case of two Grouse hens sitting side by side each on six eggs in a double nest ; and the field observer has seen two hens sitting on one nest with twelve eggs. For the following descriptive notes on the eggs of the Red Grouse in his as already pointed out, there is an interval of two months seasons. between the moult of the cock and hen. Again, it might reasonably be expected that, as the Ptarmigan and the Scandinavian Willow Grouse have not two plumages in the year, but three, some suggestion of the third plumage might be forthcoming in the Eed Grouse. But the Red Grouse has only two moults. Mr Ogilvie-Grant, how- ever, explains the position by saying that the buff and black plumage of the hen Grouse answers to the spring plumage of the hen Ptarmigan, while the buff and black plumage of the cock Grouse answers to the autumn plumage of the cock Ptarmigan. The grounds for this opinion will be considered later in the light of the possible effect which continued disease may have in permanently altering the season of the moult. Beginning now with the cock Red Grouse in January, and taking its appearance from the ventral aspect first, the uniformity of the series Grouse in is a very conspicuous feature. Every healthy bird is chestnut or rufous-chestnut and black, with fine, almost vermiculate black cross- lines over it. Even in the blackest birds the throat and fore - neck are always of a rich copper-red colour, with very little or no black edging at the borders of the feathers, which are usually barred with black only on the actual chin. Here there may be also more or less of white tippings, even to the formation of two white moustachios leading downwards from the gape, sometimes an inch in length. This may be a feature either of the black -type or of the red 1 (PL n. and in.). In some very red and black Red Grouse the abdominal feathers are also freely and broadly tipped with white ; and this may sometimes be seen even on the feathers of the upper parts (PI. iv.) The legs and feet are thickly feathered, and are white, or white with brownish barring. The 1 The whole chapter deals with the Red Grouse (Lagopus scoticus Lath.). The terms "black Red Grouse" and "buff-spotted or white-spotted Red Grouse" must not be confused with similar terms for other species of Grouse. p/. //. (P.Z.S. 1910. PI. LXXIX. ) Andre & Sleiuh. Ltd MALE GROUSE, BLACK TYPE, IN FULL WINTER-PLUMAGE. PI. III. (P.Z.S. 1910. PI. LXXX.} Andre & Sleigh, Ltd. MALE GROUSE, RED TYPE, IN FULL WINTER-PLUMAGE. PL IV. (P.Z.S. 1910. PL Z.V.V.V/.) Andre & Sleign, Ltd. MALE GROUSE. WHITE-SPOTTED BIRD OF THE RED TYPE. PL V. (P.Z.S. 1910. PI. Z.V.VAY/.) Andre ,\ SK-ujh. L'd. MALE GROUSE. RED TYPE, IN FULL WINTER-PLUMAGE WITH A FEW BLACK-CENTERED FEATHERS OF THE PREVIOUS AUTUMN-PLUMAGE. PLUMAGE CHANGES OF THE COCK GROUSE 35 claws are often in this month very long and strong. Occasionally a pale bleached feather of the preceding "autumn plumage" is to be found on the flanks, middle of the breast or neck, and may be recognised by its frayed edges ; and occasionally (e.g., No. 539), in a very backward bird, there may be many such worn and faded feathers on the chest and flanks, but such u case is invariably the result of sickness. On the dorsal side there is again, broadly speaking, a general uniformity of chestnut, bright or dark, or of blackish feathers, with fine black transverse markings ; but in almost every bird there may be found a considerable number of the old black - centred " autumn plumage " feathers remaining, with their frayed and faded edges of whitish-buff (PI. v.). On the lower back and rump the more worn and faded feathers predominate. The primary and secondary quills are all complete, and are but a few months old, having been renewed between June and August ; and the same may be said of the rectrices. The following points in the cock Grouse of January are characteristic. (1.) The rich copper-red, generally unbarred feathers of the throat and fore-neck (PI. xvi., Figs. 3 and 4). (2.) The fine barring of the chestnut, dark rufous -chestnut, or blackish- brown of the back, with the scattered black-centred feathers of the last " autumn plumage." (3.) The thick, white feathering of the feet and legs, which soon becomes blackened and worn by the "burrens" or "colons," the charred stalks of old burned heather. (4.) The perfect flight-feathers of the wings and tail. (5.) The very large claws. In February the cock Grouse is still in the darker winter plumage. Young, sheathed and growing broad - barred feathers, the remains of February. the " winter plumage," may still occasionally be- found on the hind- neck, nape, and head in backward birds. In March the cock Grouse normally shows no change ; but towards the end of the month in exceptional instances individual birds may be found with a few precocious feathers of the autumn plumage making their appearance on the back of the head and neck. These are very probably feathers irregularly developed to take the place of those which have been lost during encounters with other males. In April the cock Grouse still shows no change. In this month there are 36 THE GROUSE IN HEALTH AND IN DISEASE often greatly increased opportunities for the addition of skins to a collection, because it happens to be a month of very high mortality from " disease." The birds are found and can be collected not only by the keepers who are out early in the month in search of fox-earths, and who are generally also burning heather about this time, but also later by the shepherds who are constantly ranging the moor in the lambing time. During the last five years there has been a great accession of Grouse skins to the Inquiry's, collection in March with a very large proportion of males badly diseased, and comparatively few birds in perfect health. Therefore, in the series of skins. of cock birds representing the month of April, the great majority are very backward. Healthy birds have still the old, rich, red, copper - coloured throat of the winter plumage, and fresh - looking " autumn " feathers round the neck, upper back, and mantle, while the winter and old autumn plumage of the rump and back is bleached and faded. The backward birds are easily picked out, as they have not yet assumed their " winter " plumage, and are still mostly clad in old, worn autumn plumage of the previous year. If an April bird has newly and thickly feathered legs and feet, it means, almost certainly, that the " winter " plumage has been put on very late. The healthy Grouse should now be moulting the feathers of the feet and legs, so that bareness or lack of feathers becomes in them a sign of health in April,. and thickly feathered legs a sign of sickness ; this is the precise contrary of what has almost become proverbial on the moor, that bare legs indicate disease ; though for the later autumn months the saying is quite true. In May the preponderance of cock birds found dead, and therefore of skins of cock birds in the May collection showing belated moult, is again, a large one. The healthy cock is still in his much-worn winter plumage, but on the head and neck some feathers of the new autumn plumage are beginning to make their appearance (PI. vi. and vn.). In June as a rule, the mortality amongst adult birds, due to Strongy- losis, is coming to an end ; but for the young chicks June and July are often fatal months owing to Coccidiosis. Late in June the healthy June. cock Grouse can at last be said to have changed into his com- plete " autumn plumage." The winter plumage persists only on the abdomen and lower breast, on the actual chin which is blackish with a few white spots, and on the throat, where a few red feathers still remain. The moulting of the quills and tail feathers commences towards the end. PI. VI. (p.z.s. i9io. PI. Lxxxnr) Andre & Sleigh, Ltd. MALE GROUSE SHOWING MARKED BEGINNING OF THE AUTUMN-PLUMAGE ON HEAD AND NECK. PI. VII. (P.Z.S. 1910. PI. LXXXIV.) Andre & Sleigh, Ltd. MALE GROUSE CHANGING FROM WINTER- TO AUTUMN-PLUMAGE. PLUMAGE CHANGES OF THE COCK GROUSE 37 of the month. The rump and back are now completely covered with new black - centred feathers carrying broad - barred buff and black bands, and a few have a whitish terminal spot, similar to that found in the female. The head and neck, breast and throat, are now clothed in broad - barred buff and black feathers, quite distinct from the more chestnut and more finely black-marked plumage of the winter. It is impossible on seeing a series of the birds showing this distinctive change to avoid noticing how closely this autumn plumage of the cock approximates to the nesting plumage of the hen, and yet it is wrong to think and to speak of this "autumn" plumage as an " eclipse " plumage, for it has arrived in the cock just two months later than it is normally due in the hen far too late to be a breeding plumage. It appears almost as though the pathological postponement of the moult, a postponement which is, after all, nothing but a sign and a symptom of disease, has gradually developed into a normal habit in the life of p oss jbi e the bird, and one is led to think that this habitual disability in the postpone- cock Grouse, which results from Strongylosis during the nesting, ment - courting, and breeding season (a disability which causes the death of about eight cocks to every hen in April and in May), may have caused the altera- tion in the season of the moult, simply because the vis vitce of the cock bird, insufficient as we now know it to be at the close of winter for the ordinary calls of reproduction, would be still more disastrously insufficient if preceded by an early moult. At the present time the cock undoubtedly breeds in the winter plumage, without any further acquisition of new feathers, and, as has recently been pointed out by Mr Ogilvie-Grant, what have been regarded by Mr Millais as new "spring feathers" on the neck are in fact the old autumn feathers, which on that part of the body do not become worn and faded. That any feather of the Grouse, either in the cock or in the hen, was ever altered as to its pigment either in pattern, or in tone, or in change in any other character, when once it had completed growth and had {JJS^b. been cut off from the circulation, is at present an assumption which able- is not well supported by the physiology of feather growth. Metchnikoff's observation upon the migration of leucocytes into hair and their action in removing pigment cannot for one moment be adduced as conclusive proof that the same thing may happen in the case of a full-grown feather. While the circulation is active in the feather shaft, and for as long 38 THE GROUSE IN HEALTH AND IN DISEASE and in so far as it continues, pigmentation may be altered, but once the circulation has ceased beyond the entrance to the base of the shaft, and once that the feather, although still attached to the epidermis, is cut off from the circulation in the deeper living layer of the skin, then the feather is no more likely or able to change the pigment which is responsible for its pattern or its colour than would be the same feather had it been plucked out and kept entirely separate from the bird. Once the feather is full grown, and the circulation in it stopped, there is no reason to believe that any thing can alter it save sunlight and water, and oil supplied as an external unguent from the oil gland. That appearances are most deceptive in this respect must be allowed. Feathers may be collected from the flanks of hen Grouse which show every possible graduation Pigmenta- between the almost vermiculate flank feather indicating the perfect winter plumage, and the broad-barred breeding-season flank feather of the summer hen. But it is very much more probable that the growing period of these ambiguous or intermediate feathers is one of great susceptibility to outside conditions, as we know to be the case in respect of the metabolic processes which are taking place within the hen bird at the time. Pigment is indis- putably a product of tissue metabolism. It is often probably a mere waste product, but it appears at times to serve a special function notwithstanding. It is also certain that pigment is a production whose appearance, or failure to appear, is open to considerable vicissitudes in consequence of small recognised changes in physiological condition, and of some less easily recognised changes in the general metabolism of the body. In the hen Grouse during the breeding season we know that pigment production is very actively at work, for we know that a very large amount is being produced for excretion in the pigment glands of the lower part of the oviduct. This pigment, moreover, is precisely of the shade and colour which is characteristic, not of the breeding plumage, but of the winter dress of the hen and the cock Red Grouse. It is normally deposited in abundance on every egg, but on the other hand it may abnormally fail to be deposited or even produced at all, not only in the eggs in the oviduct, but in the circulating blood of the bird's whole system. Thus the feathers, instead of becoming buff or brown, reddish or even black as they proceed in growth, may be any intermediate paler shade of buff, or even white, a character which is due generally to the complete absence of all pigment granules. The place of PLUMAGE CHANGES OF THE COCK GEOUSE 39 the pigment in such feathers is probably taken by shining air globules, as it is in the hair and feathers of the majority of white animals and birds. It is thus easier to believe that a sudden check, either by a change of temperature, or by wet and cold, or by want of sunshine, or by change in food, has for the time so far affected the tissue metabolism of the bird that a feather which began to grow upon a circulation lacking pigment particles, and which was therefore originally planned for the paler plumage, may, by a sudden increase in the metabolism of the bird, and so in the output of waste products to the blood, be completed as a feather of the more deeply pigmented plumage, thus producing a feather with the characters of both. This is a plausible explanation, but is still open to some doubt, for the difference between the broad - banded buff and black flankfeather of the nesting hen, and the dark red-brown finely cross-lined feather of the same bird in winter, is obviously greater as regards pigment distribution than as regards the actual quantity of pigment deposited in the feathers. If there are, as has been held, distinct pigments, such, for example, as buff, black, and orange-red, in the various colour-tones of the Red Grouse, it becomes easier to see that the loss of the red pigment, which is utilised for the eggs, leaves the buff and the black in greater quantity for the nesting season plumage. In the winter all three would once more be available. The fat of the nesting hen is distinctly rich in colour, but in no case that we have seen has it amounted to the orange-coloured fat which ia often seen in overfed Pheasants, and quite commonly in Gulls and Terns which have been feeding on red crustaceans. In these birds the orange-red fat or oil, tints not merely the fat beneath the skin, but even the white feathers of the breast and body often present a very beautiful rosy flush. The whole question of pigment production and pigment distribution, intimately connected as it is with the question of the excretion of waste products and the deposition of fat, both in health and in disease, has not reached a stage which admits of dogmatic statement upon the subject of pattern change in feathers without moult. One recognised method of changing a colour-pattern in feathers without moult is to be seen in the male of the familiar House Sparrow, which produces a handsome jet-black cravat in the breeding season, where before was a nondescript greyish throat; and this it does by the simple process of 40 THE GROUSE IN HEALTH AND IN DISEASE shedding the grey ends of the feathers, leaving the blacker parts exposed. This method is common among birds, but the Red Grouse has been credited with changing in situ the colour and pattern of the flank feathers. Now, with still less reason as it seems, the cock bird has been credited by Mr Millais with achieving his summer or breeding plumage " for the most part by repig- mentation and pattern change of most of the winter feathers below the neck." This view cannot be upheld physiologically, and there is much to support the contention that the feathers which are believed to effect this change of pattern without moult are actually new growing feathers. This can readily be shown by the demonstration of their unshed sheaths. The misleading birds are again in this case the cocks which have been too sick to shed the previous "autumn plumage," and so are still struggling, with increasing success as the food improves, to produce a " winter plumage," which they should, and would in health, have achieved in October. That the cock bird should moult the feathers of the legs and feet between March 30th and June 17th is no longer difficult to understand when the prevalence of Strongylosis is fully grasped. No bird is safe from the nematode infestment, and we are led to think that the majority of cock birds are so badly infested that they are forced to defer the autumn moult which should precede that of the previous winter. It is therefore obvious that between March and June there will be every stage of good or bad leg and foot-feathering between the newly acquired thick, white winter stocking of the sick cock, and the naked featherless clean moulted leg and foot of the really healthy male bird in June. In July, again, the healthy cock bird will be found beginning to produce white feather tips over the legs and feet. In July the general appearance of the healthy cock is much lighter in colour-tone, and much more broken and mottled in pattern - character than that of the same bird in the winter. The claws are in many cases now ready to be shed, and the primaries, secondaries, and tail feathers are in moult. Some six or eight new clean- grown primaries are often to be found in July, and the long tail coverts are broad-barred buff and black. In August the cock Grouse has, of course, the appearance of full summer or autumn plumage, but it requires very little examination to see that he has already begun to put on feathers of the winter plumage. 1 " Natural History of British Game Birds," p. 40. PLUMAGE CHANGES OF THE COCK GROUSE 41 He now rapidly sheds the old feathers of the last winter's plumage which remained throughout the summer upon his breast and abdomen, and replaces them with the exceedingly handsome narrow cross-barred red or brown or blackish feathers of the coming winter plumage. There is no second moult or replacement of these feathers of the breast and abdomen in the cock. Once in the year is enough for this special area, and the feathers that " carry through " are wholly of the winter plumage. They are often broadly tipped with white. The chin feathers which survived with those of the breast and abdomen are now also replaced by new ones. It is noticeable that in the Ptarmigan it is also the white feathering of the chin and of the breast and belly, as well as of the wings and tail, which is changed once only in the year, exactly as with the winter plumage of the Grouse. It suggests that these two plumages are analogous in each species. The plumage changes in the Ptarmigan are, strange to say, quite different to the changes in the Grouse. The Ptarmigan has three distinct moults and plumages in the year. The Red Grouse has but two. In August, as has been said, the cock Red Grouse has begun to put on his winter plumage. The feathers of the breast and abdomen are full of sheaths and sheath-scurf, the growth of these feathers being very rapid and often scarcely noticeable. On the rump, back, and to a less extent on the shoulders, new rich red-brown feathers finely marked with black lines are showing here and there. Primaries, secondaries, tail feathers, and coverts are now replaced by new and blackish feathers with perfect and unbroken outlines. Even a few new rich copper-coloured feathers are appearing as isolated touches of bright colour amongst the faded broad -barred autumn feathers of the upper breast. The feet and legs are bare, save where new white feather tips are just appearing through the skin, and the claws of all the healthy birds are being shed (PI. xni., Figs. 3, 4, 5, 6). In September the chin and throat of the cock Grouse are a mixture of many pale autumn feathers much worn and faded, and a few new s copper-red ones. Most of the frayed "autumn plumage" feathers tember - are now falling out. The breast and abdomen, wings and tails, are clothed with altogether new feathers, while the head and neck, back, shoulders, rump, and coverts of the tail are in a transition state, the "autumn" feathers frayed and bleached at the tips, contrasting with the new rich chestnut and darker brownish winter feathers with their fine black transverse markings. 42 THE GROUSE IN HEALTH AND IN DISEASE The feathers of the legs and feet of healthy birds are rapidly growing to form thick, white stockings for the winter. Bare legs in September are a sign of belated moult or, in other words, a sign of sickness. In October, for the first time since the preceding winter, the red and black varieties of Red Grouse become once more conspicuously distinct. This result is due to the new growth of fully pigmented feathers, either red or black, upon the under surface of the body. The upper neck is rapidly becoming copper-red. The chin and throat still show a proportion of the faded buff "autumn" feathers among the red, the former looking spotty and pale. On the back the new chestnut and black feathers are rapidly replacing the faded autumn feathers. Some perfectly healthy cocks still look as if in " autumn plumage," while others, on the contrary, have nearly com- pleted their winter dress. The legs and feet are thickly covered with white feathers, and the nails are uniformly small, as the old claws have all been shed. Their growth, however, is extremely rapid. In November and December the cock Grouse drops most of the remaining "autumn plumage." By the end of the latter month his moult is corn- November * and plete, but on the neck and back a greater or lesser number of these December. autumn feathers are retained till the following summer. The most striking characteristics of the winter plumage are the rich copper - coloured neck and throat, and, in the darker varieties which are common in the Scottish Highlands, the contrasting blackness of the upper breast and abdomen often broadly flecked with pure white tips. Amongst the cocks there are several well-defined and easily recognised varieties, which seem to have a certain regularity of distribution geographically. These will be considered below. It must not be forgotten that, owing to innumerable efforts, which have been more or less successfully made from time to time, to transfer Red Grouse from one part of the country to another, the distinction of local variations has become a thing of the past, and is now impossible except upon a very limited scale. The attempt, however, can be made, and the number of specimens in the Committee's collection of Red Grouse skins makes it possible to arrive at some conclusions. PLUMAGE CHANGES OF THE HEN GROUSE 43 PART II. PLUMAGE CHANGES OF THE HEN GROUSE. The two changes of plumage in the hen Grouse are completed, as has already been explained, in the one case by the end of April or the begin- ning of May. and in the other case by July and August. J J J Seasonal The actual feather changes in both cock and hen are really very changes of plumage. comparable in character, notwithstanding the difference as to season ; and allowing for the difference of two months which makes the moult in the two sexes asynchronous, they may be described and explained in very much the same terms. Mr Ogilvie-Grant was the first to draw attention to the exceptional want of agreement in the seasons chosen by the two sexes of the Red Grouse for their moult, and as in the cock's plumage he makes use of the i Explana- terms "autumn and winter - summer or "winter plumages, tionof which have therefore been used here, so in speaking of the hen's plumages it will be well to adhere similarly to the expressions used by him, and to call them "summer" and " autumn - winter " or "autumn" plumages. Exception may be taken, and indeed has been taken, to these names, as being inappropriate and inexact, but they are sufficiently exact for all practical purposes, and so long as moults and plumage changes are not completed in a week, but are spread over a period of several months, so long will there be some inexactitude in the terminology of these moults and plumages if they are named according to the months or seasons. It is immaterial so long as the term is sufficiently defined, for it is obviously impossible to use a term so exact as to require no definition. The hen Grouse moults twice in the year, and wears her "summer plumage" as the breeding dress from April to July, and her "autumn" or "autumn to winter" plumage from August to March. These changes may be expressed in terms of comparison with the cock, as a case of plumage change in which the hen has two annual moults, exactly as has the cock, but both moults occur two months earlier in the hen than in the cock. The hen's "summer" or breeding plumage is a very beautiful dress, 44 THE GROUSE IN HEALTH AND IN DISEASE variable to a considerable extent it is true, but yet having a general uniformity which becomes the more obvious as a greater series of skins in any particular phase of plumage is examined. Opportunities for even seeing the hen Grouse, to say nothing of obtain- ing her skin, in the full breeding plumage are rare ; and thus it happens that, even in the large series of Grouse skins at South Kensington obtaining and at Cambridge, this phase is only poorly represented, ousting The Committee has been to some extent more fortunate, and p umage. ^ ag ^ a j ne( j a g rea t many skins of hens in the summer plumage (see p. 54 and Appendix D), so that points of resemblance can be noted at sight, and individual variations perforce take their proper places. It has been a marked feature in the whole collection of six hundred skins that as the series grew, and the general uniformity became more marked, the individual variations of which we were inclined to make much at first, became gradually relegated to their subordinate position. Uniformity, albeit with endless minor variations, is the rule in the Grouse as it is in every other creature that leads an unprotected existence under natural conditions. How long it will continue in the protected, often over-protected, Grouse remains to be seen. It is possible that such variation as already occurs is to some extent a modern development ; but on this point there is at present insufficient evidence to amount to certainty. Beginning once more with January, it may be said that in this month some hens, when examined on the under side, are hardly distinguishable by their plumage from some cocks (PL vin.). On the dorsum it is different, and a healthy hen in January is unmistakable owing to the terminal spots of buff which appear almost invariably, though occasionally in limited numbers, on the feathers of the back. In some healthy hens the chin is sometimes still pale buff in colour, owing to the persistence of summer-plumage feathers of the preceding year. The throat and fore-neck, on the other hand, are copper-red, but rarely so uniformly red as in the cock (PI. xvi., Fig. 1). The copper - red feathers seem to begin on the fore-neck and proceed towards the chin, so that the chin often remains buff and black when the throat is already red. Except in very backward birds, which have been sick, the old and faded broad-barred feathers of the flanks are never found in January. The legs and feet are white and thickly feathered, and the claws are long and strong. PL VIII. (p.z.s. 1910. PI. /.v.v.vr.) Andre * Sleigh, Ltd. FEMALE GROUSE, BLACK TYPE, IN AUTUMN-PLUMAGE. PI. IX. (P.Z.S. 1910. PI. Z.V.VAT/7.) \ k % * Andre & Sleiiih. Ltd. FEMALE GROUSE, RED TYPE, CHANGING FROM WINTER- TO SUMMER-PLUMAGE. PI. X. (P.Z S. 1910. PI. LXXXVl') Andre & Sleigh, Ltd. FEMALE GROUSE IN FULL BREEDING-PLUMAGE. PLUMAGE CHANGES OF THE HEN GROUSE 45 In February the bird is still in the same plumage as in January. In a few forward birds the feathers of the summer dress are beginning to make their appearance on the back of the neck about the middle of the month. In March the change from autumn plumage to spring breeding plumage is, in healthy birds, now quite unmistakable, though many birds are very backward owing to disease. All doubt as to the sex of healthy birds, whether from above or below, is now removed. The broad- barred buff and black feathers of the flanks are now appearing, and are most conspicuous and characteristic, while the whole of the lower breast and abdomen covered by the red-brown or red-black finely barred feather of September growth are still in excellent condition and remain unchanged (PI. ix.). The feathers of the chin, throat, neck, and upper breast are now mixed with broad-barred black and yellow feathers in forward birds ; while in backward birds the throat and fore-neck may still be clad in copper-red feathers. The legs and feet are already looking worn and less well feathered, but the claws are long. In April and in May, for the simple reason that many hen Grouse died of "Grouse Disease" in these mouths during the six years of the Inquiry, the proportion of skins of backward hens is large. The birds thus April and picked up dead carry one immediately back again to winter, for **? although they ought by this time to be putting the finishing touches to their spring plumage, they are, in fact, but just succeeding in the belated effort to put on the autumn dress. They are thus a clear six months late, and afford the most misleading seasonal characters imaginable. Their legs and feet, instead of being worn and almost moulted clean, are at last, after a winter spent with almost naked legs, well-clothed with thick white feathers. The appearance of the legs therefore in the hens, as in the cocks, is totally misleading to the keeper or to the sportsman who considers bare unfeathered legs to be a sign of " Grouse Disease." This holds good for autumn only, and in spring precisely the opposite is the case, for in April, May, and June none but healthy birds have naked legs and feet. The general character of advanced and healthy birds towards the end of April and in May is that of a complete spring plumage. The whole of the upper parts are broadly barred with buff and black, and marked with con- spicuous terminal whitish buff spots or bars (PI. x. ). The under parts, again, are 46 THE GROUSE IN HEALTH AND IN DISEASE broadly barred with bufi' and black, from the chin to the throat and neck, over the breast and down the flanks, while the central lower breast and abdomen are still in the autumn plumage of the previous September (PI. xi. and xii.). White terminal spots may, of course, be present on the breast and abdomen. These are a local or an individual character which will be mentioned later in dealing with varieties of feather pattern and coloration. The flank feathers of the hen in the full spring plumage show much diversity of pattern. This diversity even in the same individual bird Change of has l e & to the belief that the pattern may be changed in an unmoulted o? 1 im- ta feather from the autumn plumage arrangement of red -brown and probable. re( Jdi s h - black finely barred with lines of black to a much bolder barring of buff and black. It has been surmised, from the examination of single feathers, that the change commences in the centre of the feather on either side of the shaft, and gradually produces another pattern of a totally different colour. But can this be possible in a feather which has long been fully grown, and which has presumably been long cut off from any blood or lymph supply, and which is as dead as if it had been shed? (PI. xn.). It is almost certain that re-arrangement of the pigment or of the pattern in this way is out of the question, and the reasons for this view have already been discussed. 1 The legs and feet of the hen Grouse in April and in May are very poorly feathered, and the claws are very long (PI. xin., Figs. 3, 5). In June the legs and feet are almost bare, and the claws begin to drop off (PI. xm., Figs. 3, 4, 5). The precise date of this shedding of the claws is again really a part of the moult, and is, in consequence, equally dependent upon the health of the bird. Sick birds which have sur- vived the spring mortality are always late in the shedding of their claws, and shedding equally late in the changing of their feathers. The claws are shed, of claws. both in health and in disease, but once a year, and the casting is synchronous as a rule with the disappearance of the autumn dress. The figures (PI. xm.) by which this process is illustrated require but little explanation. The whole of the year's growth of horny black nail becomes loose on the soft and growing vascular matrix, and when quite ready to be cast can be easily pulled off like a little cap. The young nail beneath is at first soft, pink and vascular and very short, but soon hardens and deepens in colour, and in a month or two has grown to be a useful nail of horn. The transverse or circular groove which is 1 Vide pp. 37-40. PI. XI. (p.z.s. Andre & Sleigh, Ltd. FEMALE GROUSE IN FULL SUMMER-PLUMAGE. PL XII. (P.Z.S. 1910. PI. AT.) Andre & Sleigh, Ltd FEMALE GROUSE, RED TYPE ; FEATHERS FROM FLANKS. Female grouse, red type, feathers from Hanks. Natural size. Fig. a and c (from \o. 1864), g and h (from No. 226), and k (from No. 632). are varieties of the spring Hank-feathers. Fig, b (from N.I. 575' is a Hank-feathjr from a very black hen. Fig. d from No. 1864) is an example of what is termed line-barred, dark-red winter-plumage, with narrow black bars or lines on rather dark rufous chestnut, the latter being slightly bleached towards the tip. l-'igs. rand/ (from No. 18641 and / and in (from No. 664) illustrate interme- diate stages of colouration, the feathers probably having broken through the skin when winter-conditions prevailed, and having completed their growth under summer-conditions. Fig-;, /' and it (from No. 664) illustrate the reasoning upon which is based the view just mentioned ; of these two feathers there is no doubt that n was being grown much later than i, and therefore more in summer-condi- tions, producing summer breeding-plumage. PL XIIL (P.Z.S. 1910. PI. AT///.) Andre & Sleigh. Ltd' FEET OF RED GROUSE : (1) NEW WINTER-FEATHERS AND NAILS ; (2) FULL WINTER-PLUMAGE (3) (4) (5) and (6) SHOWING STAGES IN MOULTING OF NAILS. XIII. Grouse, red type, feet showing winter-plumage. Fiji. 1- Right foot showing new winter-feathers and new nails (Xo. 1177). 2. Left foot showing full-feathered winter-plumage. Feet of grouse, showing replacement of nails. Fig. 3. Right foot <\o. H4K) with old nails ready to he shed. ,. 4. .. in median vertical section. .. 5. Left .. (Xo. 1167). 5a, old nails ; 56, new nails ; Sc, shed nails. .. 6. Right (Xo. 1185) with new leathers and new nails. PI. XIV. (P.Z.S. 1910. PI. Z.V.V.Y/.-V.) Andre & Sleigh, Ltd. FEMALE GROUSE SHOWING BARE PATCH OF SKIN AND DOUBLE LINE OF BARRED FEATHERS ON ABDOMEN. PI. XV. (P.Z.S. 1910. PI. .VC/.) T ; Andre & Sleigh, Ltd. FEMALE GROUSE, RED TYPE ; WORN UPPER TAIL-COVERTS. PLUMAGE CHANGES OF THE HEN GROUSE 47 left at the point of detachment of the old nail is quite a useful indication of age in cases where there is a doubt as to a bird being over twelve months old or of the year. The presence of the groove showing that the claws have once at least been shed is conclusive proof that the bird is more than twelve months old. In June there is another characteristic appearance in the hens, namely the bare patch of abdominal skin which results from the shedding of the abdominal feathers, grown in the previous September. The loss of these feathers r _ Bare patch leaves a naked patch of skin on the abdomen of a hen that has been on abdo- sitting, and this patch remains naked for the next few months (PL xiv.). The general character of a June hen in health is that of the completed summer-nesting plumage, broad-barred buff and black over all the upper and under parts, excepting the abdominal area, the lower breast, wings, and tail. But it looks already somewhat faded and worn ; and it is quite probable that in acquiring so perfect a plumage for sitting unnoticed on a nest built amongst the heather, the economic absence of the redder pigment in the feathers is in part a result of the acknowledged fact that for longer and more trying use, and for wear and tear in feathers, darker pigments are required, whereas for the short- lived and less exacting requirements of the summer plumage in the hen Grouse from April to June the buff and black feathers, with very much poorer wearing qualities, are found to be sufficient. The accompanying figures of a few worn- out and moulting feathers taken from a hen in summer plumage, show how distinctly better the black pigmented parts of the feather stand wear and tear than the yellow parts (PL xv.). Certain pigments have a value, therefore, of a very practical nature apart altogether from the aesthetic point of view of attractiveness, or the rather hypothetical view of assimilation to surround- ings for purposes of safety or to assist in obtaining food. He would be unwise, however, who denied that all three factors play a part in the very beautiful nesting plumage of the hen Grouse. It very occasionally happens that the hen Grouse, instead of retaining the redder plumage of the previous autumn's growth on the abdomen until it drops off during incubation, grows an almost universal spring plumage . of buff and black broad-barred feathers covering the lower breast sometimes ' absent. and abdomen as well as the remainder of the body from head to tail. A skin showing this condition is preserved in the National Collection, and there is an almost equally perfect specimen in the Committee's Collection, No. 919. 48 THE GEOUSE IN HEALTH AND IN DISEASE The more usual procedure is that the abdominal patch of autumnal plumage is lost during incubation, and is then quickly replaced by a renewal of the autumnal feathers when the spring plumage is also being shed. growth on There remains, however, in the majority of birds, a very quaint abdomen. J J J growth of belated spring plumage, consisting of buff and black- barred feathers in two lines down each side of the centre of the naked patch, as though, for some occult reason, the intention to grow "spring- plumage" feathers upon this area had never been altogether lost. This peculiar persistence of belated intention shows itself as a patch of yellow feathers made up of the two lines of feather growth in the midst of a much broader area of the autumn red pigmented feather which one would expect to find all over the abdomen (PI. xiv,). It is conceivable that a small persistent remnant such as this, having no obvious connection with the surrounding plumage at the time, or with the habits of the bird, or with the seasons, may yet have something to do with the third or lost " eclipse " plumage which is still to be found in the grey plumage of the Ptarmigan, but is almost completely lost in the case of the Red Grouse. In July the summer plumage of healthy hens is much worn out, frayed at the edges, and very definitely faded, and the feathers are already dropping out. On the chin, throat, and fore-neck, new red feathers of the autumn plumage, looking rich and dark, are already making their appearance. The back is as it was, but faded, and the flanks are still con- spicuously broad-barred with buff and black ; but the abdominal bare patch is now growing new autumn plumage feathers with great rapidity from the centre outwards. The primaries and secondaries have now commenced to moult. There may be in July, in the hen, as many as six or eight old primaries in each wing with frayed tips, still to be renewed. Precocious young birds of the year can still at once be distinguished from hens in moult, because in the former the dark red-brown black-lined autumn Distinction plumage is on the flanks, while the broad-barred buff and black, and ^m^nd ra ther worn-out chicken feathers are in the centre of the abdomen. In old birds, the adult the distribution is reversed. The broad-barred buff and black feathers of the spring plumage are on the flanks, and the redder fine-barred autumn plumage is appearing in the centre (compare PI. xn., Figs, a, c, g, h, k, and n, with Fig. d.). In skin No. 284 there seems to be an unusual compromise in a very backward hen, owing to disease. The compromise is between the ; If) N (X tu o o Id j - fti I! 25 II | Is u 1 o w g|| ^ u^5- < OSS s /. C/. ) Andre Si Sleigh, Ltd. FEMALE GROUSE, GREY VARIETY. (Type of L. pvrsicus, G. R. GRAY.) LOCAL VARIATION IN PLUMAGE OF GROUSE 61 with birds found dead of disease in April and in May, the discovery of the ovary is still a matter of comparative ease, and the discovery of the testes even easier. The testes are always somewhat enlarged in the spring months, whether the bird be diseased or not, and they may be the size of a pea or larger, and will generally be white. The ovary may be small, but will always be like a portion of hard cod's roe, in which the ova, though no bigger than a pin's head, are distinct and numerous. The undeveloped ovary of an adult female Grouse would about cover a threepenny piece, but is long and triangular in shape rather than circular. The oviduct in a breeding hen is a large and conspicuous duct, and may, of course, contain an egg with the shell in course of formation, being pigmented in preparation for laying. The oviduct in a barren bird, or in a hen at other times than the breeding season, is a very much less conspicuous object, and is less easily found than the small and undeveloped ovary. If no ovary is seen, but a very small blackish, or whitish, or parti- coloured object is found in its place which is suspected of being a testis, the intestines must then be gently separated from their attachments about the middle line of the back, and the other testis must be sought for in about the same position on the opposite side. Even in a young bird the ovary shows ova with sufficient distinctness to make doubt as to its sex an impossibility ; but in a very young male bird the testes may be so small, and, being very often black, may look so unlike what is expected that both should be sought for and found before arriving at a certain conclusion as to sex. It is easy, if the intestines are roughly handled, and the attachments torn carelessly away, to carry away the testes or the ovary from their proper position, and to remove them with the intestinal attachments. The peritoneal folds are delicate and require careful handling, and they overlie the generative organs and the kidneys; but a very little practice will enable any one to do the necessary dissection with certainty, and to arrive at an irrefutable diagnosis as to sex. It may be said that there is no other infallible means of arriving at the sex of a Grouse at certain times of the year, for it has so often happened that experienced and careful gamekeepers, who have handled Grouse for a lifetime, have certified a specimen as a cock, when the specimen has turned out to be a hen, and vice versd. The mistake is unavoidable and excusable, 62 THE GROUSE IN HEALTH AND IN DISEASE for in certain individual Grouse in the autumn-winter plumage there is no reliable characteristic in the feathering or in the supraorbital comb (PI. xvi., Figs. 3 and 4), or in any external part of the bird, by which the sex can be distinguished. In most Red Grouse, even in the vast majority, the confusion of sex is not possible, for it is a matter of common knowledge that for a great part of the year the cock and the hen are so wholly unlike one another as to make it difficult for any one who did not know the birds to believe them to be of the same species. Even in the summer months when the cock puts on a plumage closely simulating the breeding plumage of the hen, there is a difference in the general tone and colour, and confusion is not likely. But in the autumn and winter it is com- paratively easy to mistake the sex of some individuals, for when the hen has put on her autumn plumage for the winter, and the cock has put on his winter plumage, certain individuals of opposite sex are then indistinguish- able, even to the practised eyes of the experienced gamekeeper. Generally speaking, the feathers of the head and neck give the best indication as to sex in the autumn - winter plumage. In the male the red colouring is, as a rule, far more uniform than in the female. In the male also there is, as a rule, an absence of black markings on these red feathers, except on the upper part of the head, on the crown, and nape of the neck. The cheeks are generally a clean bronze or chestnut-red colour ; so are the feathers of the chin, throat, fore-neck, and upper breast, giving the bird a very rich uniform red colour all over the head and neck. In the hen, as a rule, the whole of the feathers of these parts are crossed by narrow black bars, which give her more of the mottled and broken colouring which the cock bird only begins to assume in the early summer when he puts on the first feathers of his autumn plumage. The feathers of the chin are a very useful indication of sex from August to November, practically throughout the shooting season, for the chestnut-red feathers which can be found on the chin of the cock Grouse in every month of the year will be sought for in vain in the hen at this time. Even in December and January they are so imperfectly red as compared with the same red feathers in the male that one may almost say that red feathers are to be found on the chin of the hen only from February to July, when they become conspicuous on account of the contrast in colour with the increasing yellowness of the breeding plumage. These red feathers persist from her previous LOCAL VARIATION IN PLUMAGE OF GROUSE 63 autumn - winter plumage exactly as do the feathers of the lower breast and abdomen. This persistence of winter-plumage feathers on the chin, lower breast, and abdomen is common to both cock and hen ; but in the cock they remain, as a rule, until replaced by the following winter plumage, persisting throughout the autumn plumage change ; whereas in the hen they are persistent only to June or July, and are entirely replaced during the autumn change. Even when the autumn plumage is put on, the yellow feathers of the preceding breeding plumage are almost always to some extent persistent, and they are to be found in the chin of the hen bird even though the throat and neck may be unusually red and therefore unusually like those of a cock bird. From January to May there is no possibility, as a rule, of confusing the sexes. In June and July confusion is unlikely, but in August and onwards to December the differentiation of the sexes by the plumage is sometimes a difficult thing, and the best guide is the persistence of feathers of the preced- ing plumage such as occurs upon the chin in particular. We must recollect that the dominating plumage of the male is the winter plumage, while that of the female is the summer or breeding plumage. In the autumn, especially from September and October onwards, there is the additional difficulty of distinguishing old birds and young. " Young birds in July resemble the adult female in breeding between plumage in their general colour, but the flank feathers of the adult young plumage begin to appear about this time. By the month of November the young are generally not to be distinguished from the adults." This quota- tion is from Mr Ogilvie-Grant. There is one sign of age in the majority of birds in the shooting season, if it has not become obliterated namely, the mark across the claws of recent shedding. Very often one may find the nails or claws still adhering Groove to the toes, though ready to drop off, so that a gentle application of onolaw - force removes them like small caps, leaving the new shorter claws beneath, each marked by a groove where the old claw was attached. This groove persists often for some little time, and is an infallible sign that the bird is over a year old at least. Young birds of the year do not shed their claws, and therefore never have this groove. There is another method of determining a bird's age which is often used as a rough indication upon the moor, namely, to pull out the third primary 64 THE GROUSE IN HEALTH AND IN DISEASE feather of the wing at its distal end. If blood can be squeezed from the quill Wing it is considered as a sign that the bird is of the year. If no blood can feathers. ^ e S q ueeze( j j an( j ne f ea ther is old and dry, it is considered as a sign that the bird is more than a year old. Diagrammatic Representation of the Growth of Primaries in the Young Grouse. This reasoning is based upon the following facts : When the chick produces its first set of primary wing feathers they are all very thin and weak, and soon become frayed out ; they have rather narrow pointed ends, are blackish -brown, in colour mottled with incomplete buff bars. Nine of these little feathers can be LOCAL VARIATION IN PLUMAGE OF GROUSE 65 counted in series, and the weakest of all is the ninth counting from the distal to the proximal end. The diagrams on page 64 show very roughly the sequence of growth in the primaries of chick and pullet. The growing power, as judged by the size of the root sheaths of these feathers, increases from the ninth distally, so that at one period of growth (F) the feather No. 4 is the longest, then a little later (G) No. 3, then still later (H) No. 2. But No. 1 remains permanently shorter than No. 2. By the time Nos. 1 and 2 are approaching full growth, the weak chicken feathers Nos. 9, 8, 7, and so on have been shed, and in their place have appeared strong feather - roots growing strong, round - ended, uniform black primaries, instead of the weak, mottled, more narrowly pointed chicken primaries. This shedding and replacement continues as far as No. 3 of the chicken primaries, but when No. 3 falls out Nos. 2 and 1 are found to have grown into such long and strong feathers as to fall into the series of new replacement feathers, and so they remain, now fully grown, and they can be recognised (K) by their more pointed ends having rather more of the buff markings on them than have the remainder of the primaries just grown from No. 9' to No. 3. No. 3, moreover, being the latest of the whole series of primaries to emerge, is for a time the shortest one ; and, even when as long as No. 2, will be still the last one grown, and will therefore upon withdrawal produce blood at the quill end when squeezed between the finger and thumb. This sign of blood in the quill of the third primary is not an infallible sign of youth, for it is evident that as soon as the feather finishes its growth the quill becomes as hard and dry and bloodless as all the others. The only indication will then be a slight difference in the shape and contour of the two last feathers as indicated above. Moreover, in September it is easy to find birds obviously adult with claws attached but on the point of being shed, and having all the primaries moulted except the two most distal ones. The third then will be found to be a short feather actively growing, and if it is pulled out the growing root will be full of blood. Therefore not every bird that gives this sign is necessarily a bird of the year. The condition of the ends of the primaries, and especially of the two most distal feathers will, however, be a fair indication of age. Another sign often used to test the age of a bird is the strength of the lower jaw. The weight of the bird is allowed to hang without support by VOL. I. E 66 THE GKOUSE IN HEALTH AND IN DISEASE holding the tip of the lower bill only. The bone of an old bird's jaw easily Lower stands this test, but the soft jaw of a young bird of three or four months cannot carry its weight, and the jaw either bends or breaks. Yet another test often used is that of trying to crush in the skull with the finger and thumb ; in the young bird the soft skull gives way readily, in the old bird it requires very considerable force. In judging at a moment's notice whether a young Grouse chick which rises to the dogs on the 12th is of a shootable age and growth or not, the usual Tail rule is probably as good a one as can be found namely, that there feathers, should be a very clear view of black tail feathers before the young bird is fit to kill. It is only necessary, however, to look at a few young Grouse chicks of various ages to be convinced that more than a little of the black rectrices should appear before the bird is shot. Probably most sportsmen will be guided better by the strength of the bird upon the wing than by the black tail feathers, however clearly visible in a half-grown chick. In dissection, the age of an old bird is apparent, perhaps as plainly upon the table as elsewhere. The fibrous tissues all toughen with age and use, and the bones become harder. The grits of the gizzard in an old bird seem to be larger and more worn into rounded pebble shapes, the reason for this has been discussed elsewhere. 1 The question, therefore, of deciding whether a bird is less than a year or more than a year old, is possible, but it seems almost impossible to judge more exactly of the age of an older bird by any sign to be discovered either externally or internally. 1 Vide chap. iv. p. 95. CHAPTER IV FOOD OP THE RED GROUSE By Edward A. Wilson and A. S. Leslie. PART I. OBSERVATIONS ON THE FOOD OP GROUSE, BASED ON AN EXAMINATION OF CROP CONTENTS. DURING the period of the Inquiry the contents of several hundreds of loaded crops have been examined by the Committee with a view to ascertaining the various foods eaten by Grouse ; the percentage compositions have been tabulated, as well as the total weight of food in the crops at examina- the various hours of the day, and by these means the Committee have come to several unexpected conclusions. Table I. (p. 68) shows how the three hundred and ninety-nine specimens of crop contents examined are distributed as to locality and as to date, during the three years 1906, 1907, and 1908. 1 It is natural that by far the greater number should have been supplied during August and September ; but the remainder are fairly evenly distributed. Table II. (p. 69) is drawn up to show the average weight of the crop contents of birds killed at different hours of the day, from 6 A.M. to ximeof 6 P.M. feeding. In the last right - hand column of Table II. will be found a general average for the twelve months, and it will be seen from the figures given that Grouse feed from morning until night, but that full crops are more commonly found in birds killed in the afternoon and evening, both in winter and summer, than in the morning and forenoon. When a Grouse is in health the gizzard invariably contains food under- going a grinding process throughout the hours of sunlight, even in the longest 1 In addition to the 399 crops tabulated some 1,100 other crops were examined these were obtained mainly from diseased birds in April and May, and from shot birds in August and September. 67 68 THE GROUSE IN HEALTH AND IN DISEASE summer day. The crop, it is true, is often found very full towards evening, and rarely so before noon ; but this is only because in the evening the bird feeds more heavily in order to store up food for the hours of darkness, while TABLE I. CROP CONTENTS; MATERIAL EXAMINED. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. Aberdeen . 1 1 2 Argyll 3 1 2 1 1 1 2 1 1 ... ... 1 3 ... 10 23 4 a 5 7 Banff a 2 Caithness Dumbarton . Dumfries 1 1 2 2 1 2 1 3 2 1 1 3 2 4 5 2 i 6 2 12 1 3 1 5 2 7 5 20 33 24 1 Inverness Kincardine 7 5 1 3 1 ... 1 3 38 15 1 9 82 2 Kirkcudbright 1 1 2 1 1 2 Midlothian 2 1 1 3 7 1 1 a 6 Mull 1 , . 1 Peebles 1 1 i 3 Perth . Ross 3 3 3 4 3 1 9 1 1 6 2 2 1 1 2 1 7 1 i 5 2 21 26 9 Selkirk 3 T 1 7 Stirling . 1 4 5 Su therland . 1 1 1 i 1 5 Wigtown * 1 1 Cumberland . Derby . 1 1 1 1 1 9 1 10 ... ... 2 a 16 6 D urham 1 i 2 Lancashire a 2 Northumberland 4 4 B 1 a a 15 Westmorland 9 3 a 2 1 a 12 Yorkshire 1 1 eland 1 6 5 7 2 4 7 1 i 3 36 1 Wales . a 4 a 1 5 14 33 39 33 30 16 12 12 67 44 27 15 71 399 Total number of crop contents examined = 399. during the daytime he seldom eats more than the digestive processes can deal with at the time. Hence during the early part of the day the food passes rapidly from the crop to the gizzard and on to the digesting tracts of OBSERVATIONS ON THE FOOD OF GROUSE 69 the gut proper, and the crop is left almost empty. This has given rise to the view that Grouse only feed once a day, and that in the evening. Heather (Calluna vulgaris), as is well known, is the ordinary food of the TABLE II. WEIGHT IN GRAINS OF CROP CONTENTS IN WHICH THE HOUR OF COLLECTION WAS GIVEN FROM APRIL TO NOVEMBER INCLUSIVE. Hour of Collec- tion. Weight of Crop Contents of each Bird in Grains. (April to November. ) Weight of Crop Contents of each Bird in Grains. (December to March.) Average Weight, in Grains. Apr. to Nov. Average. Dec. to Mar. Average. Com- bined Average for 12 Months. 6 a.m. " 8 9 10 11 ,, 1 10, 10 .... 1 8 No speci- men 4* 11 22 10 No speci- men 20 10 !To speci- men 5 H 8 20 7i 5J 13J 8 No specimen .... 20 1, 8 . 10 3, 18, 19, 4, 4, 20, 9 . 18, 2, 16, 27, 20, 14, 3, 13, 24, 40, 28, No specimen .... 5 36, 43, 34, 11 Noon. 12, 14, 2, 11, 18, 6, 7, 15, 21, 7, 1, 6, 15, 24 120, 10 "i 65 38 1 p.m. 18, 36, 62, 29, 32, 2, 3, 5, 13, 13, 18, 12, 19, No specimen .... 19 No speci- men 19 2 26, 45 70,60,20 .... 35J 75 55^ 3 50, 173, 98, 213, 334, 27, 7, 12, 17, 26, 18, 14, 2, 6, 8, 28, 52, 24, 48, 31, 1, 5, 68, 31, 32 110, 100, 80, 180, 358, 200, 369, 50, 380, 250, 320 53 217 135 4 15, 1, 4, 4, 246, 50, 17, 32, 50, 43, 50, 46, 8, 4, 2, 43, 3 339, 429, 239, 369, 429, 599, 280, 280 36 370 208J "' 8, 1, 1, 2, 1, 254, 66, 18, 5, 32, 23, 17, 7, 23 150, 210, 200 32 186| 109| 6 37,93,114 10, 349, 290, 20, 409 . 81 214 147J adult Red Grouse. But twenty or thirty other plants are also eaten, often in great quantities, and it is a well ascertained fact that Grouse that have never set eyes upon a sprig of heather will live and flourish for years. 70 THE GROUSE IN HEALTH AND IN DISEASE Yet the importance of heather in building up the birds for the approach of winter cannot be exaggerated, and there is little doubt that in a bad heather year all the young birds suffer, while even in a good heather year the later broods will be permanently handicapped as regards physique and disease-resisting power if they have missed the best food months. The most noteworthy fact brought out by Table II. is that Grouse appear to require a larger quantity of food in the winter months from December to March, than in the spring, summer and autumn months from April to November. 1 It is, of course, true that in a bad heather year Grouse may find substitutes for their staple diet. Of these substitutes blaeberry is undoubtedly the most valuable, as may be seen by reference to Tables III. and IV. ; 2 but Substitutes . ,',-,-, T i i for in many districts blaeberry does not grow upon the moors, and m no case is it so reliable a winter food as good heather. Other substitutes for heather are rush-heads, crowberry, bog myrtle buds, seeds of P. tormentilla TABLE III. SHOWING THE PERCENTAGES OF VARIOUS FOODS FOUND IN CROP CONTENTS OF GROUSE FROM APRIL TO NOVEMBER INCLUSIVE. April. May. June. July. Aug. Sept. Oct. Nov. Calluna (Heather) shoots, fresh and green . 47 69i/ 82 } 3H\ 59J> 31' Stt Calluna (Heather) shoots, brown but living 46 93 12 82 0>82 21* y 53 1 V66 79 11 70 15} 72 Calluna flower-buds, flower and seed-heads . i oj J 5|J 28 . 33 j Blaeberry ( V. myrtillus), stalks and leaves 4 6 6 20 4j 9 22 Various, including Erica, Crowberry Fern, Sorrel, etc. 3 12 12 27 34 16 21 6 fern leaves, bog cranberry leaves, flowers of Erica tetralix and Erica cinerea, moss spore capsules, sheep sorrel leaves and seeds, insects, and oats. On pp. 83- 87 will be found a list of the vegetable foods eaten from time to time by the Red Grouse, with illustrations of some of the plants referred to. The summer substitutes for heather, while interesting as showing the wide range of the Grouse's diet when many varieties of food are available, cannot be considered of great importance to the health of the adult bird, for if the 1 Vide also p. 79. 2 Vide pp. 76, 79 and 80. PLATE XXIII TYPES OF HEATHER. Old Heather valueless as food for Grouse. Young short Heather valuable as food for Grouse. Opposite p. 71.] OBSERVATIONS ON THE FOOD OF GROUSE 71 heather is good, and the supply sufficient, the stock will be well nourished and healthy, even on a moor where there are no berries or other miscellaneous kinds of food. Heather then is the essential basis on which the Grouse depends, and the importance of the plant is so great that it may be permitted to give a short description of the phases through which it passes during the seasons of the year. Beginning with the months of early spring, it will be seen from Table III. that in April the Grouse's diet consists of an equal quantity of fresh green heather and of brown "winter" heather. The former is more nutritious than winter the latter, but even the brown winter heather is better than nothing, heather - and is to be distinguished from withered dead heather which Grouse never eat. The fresh green heather so desirable for the food of Grouse does not necessarily represent the young shoots of the spring growth, for these do not generally appear till May, but rather the evergreen foliage which the plant carries upon its lower branches throughout the winter. No one who casually examines a Grouse-moor in midwinter can realise that the dull brown weather - beaten scrub conceals on its more sheltered twigs a luxuriant growth of vivid green shoots : these green shoots are far more numerous on short close heather than on the long overgrown heather versus long t it. i i i . -,L heather. so common on many moors, for as the plant increases in height it becomes more open in its growth and more susceptible to the blighting effects of frost and cold winds. In cases where the heather has attained a height of several feet the shelter is so greatly reduced that it is sometimes difficult to find any green shoots at all in winter unless the weather has been unusually mild ; such long overgrown heather is of practically no value as winter food for Grouse (see PI. xxiu., Fig. 1). This type of long and apparently luxuriant heather is very common on the west coast of Scotland, and in many districts in the central Highlands, and probably accounts for the fact that these districts carry a comparatively small stock of Grouse. In other districts the heather seems to have developed a short, close habit of growth to the uninitiated it would appear to be stunted and poor ; yet it is in the districts where this dwarf type of heather is common that Grouse appear to thrive type of in the largest numbers. The hills are covered with a close carpet of vegetation having a smooth level surface which may be compared to a well- clipped yew hedge this level surface forms a canopy of shelter from frost, 72 THE GROUSE IN HEALTH AND IN DISEASE while the stems of the heather are so short and stiff that they are little affected by the wind. If this type of heather is examined, it will be found that immediately below the weathered canopy there is a rich growth of bright green shoots even in the most severe winter (see PI. xxni., Fig. 2). There is no doubt that it is on the moors which have a large proportion of this short, close-growing heather that the largest stock of birds can be carried over the winter. But it is only on a special class of ground that this type of heather is found to grow naturally ; it is usually associated with dry, hard soil, good natural drainage, a rocky subsoil, and only a shallow layer of peat on the surface ; it is uncommon in districts with a heavy rainfall. Even on the best ground there is a tendency for the heather to grow too long and bushy ; but this tendency can fortunately be controlled by artificial Heather means. In another part of this Report the subject of heather burning culture. - g f u iiy described, 1 and it is only necessary here to state that, for purposes of food, heather ceases to have any value after it has been allowed to become rank. With the advent of May comes a great change in the condition of the heather plant. In this month every twig breaks out into green shoots, even the oldest and most ragged stick heather will produce young growth in growth of the kind most valuable as food for Grouse ; but it is now too late for this tardy recovery to be profitable, for the days of famine are past, and there is sufficient food to feed ten times as many birds as there are upon the ground. Even in this month of plenty, however, the close, short heather of from 4 to 8 inches in height is superior to the straggly forest of overgrown plants, for there is an ever present risk of a late spring frost, when the tender young shoots will require all the shelter they can get. The appearance of the young growth is marked by an immediate change in the diet of the Grouse. On referring again to Table III., it will be seen that the consumption of fresh green heather shoots rises suddenly to 69^ per cent., while that of the dry winter heather drops to 12 per cent. At the same time the proportion of miscellaneous foods is more than doubled, owing doubtless to the fact that every moorland plant is throwing off its winter sleep and bursting into appetising young buds. Just as the first flush of early pasture is more nourishing than the later growth, the first heather shoots of spring probably contain a larger percentage 1 Vide chap, xviii. pp. 392 et seq. OBSERVATIONS ON THE FOOD OF GROUSE 73 of nutritive food than at any other time of the year, and it is doubtless due to this cause that Grouse make such rapid growth in size and young strength between the date of hatching in May, and the opening f^y'* of the shooting season some ten or twelve weeks later. It is in the month of May also that the young heather plants first begin to appear on the black ground, where the old heather has been burned. The length of time that elapses between the date of burning and the growth of the new heather varies. If the roots are not too old, and young plants. have not been destroyed by the fire, the new growth will spring from them within a year ; on some ground this always occurs. If, however, the roots have been burnt out, or are too old to send forth new shoots, the ground must lie waste for years, until a fresh growth of heather springs from wind-blown seed or from the seed lying dormant in the soil or blown on to it. 1 It is usual to suppose that the first shoots of the young heather as they appear above the ground are greedily eaten by Grouse. Observation has shown that this view is not strictly correct, for the adult birds will * Adult never feed on the immature plant so long as they can find plenty Grouse do of close-growing heather of the type described on p. 72. This is seedling 3 * heather. fortunate, for otherwise the first growth might be very severely checked on a moor carrying a heavy stock of birds. Sheep, on the other hand, are very fond of the tender young shoots, and are often most destructive to seedlings which have not had time to secure a firm roothold. While the adult Grouse does not eat the very young heather, there is no doubt that the chicks prefer it to the shoots of the more mature plant ; but the amount eaten by them in the days of their infancy Grouse is so small that they cannot make any material impression on the growth of the plant. In June there is a continuance of the favourable conditions which com- menced in May. It will be seen by reference to Table III. that in this month the consumption of fresh green shoots of heather rises to Heather in 82 per cent., while that of brown winter heather drops to zero. June- In July the consumption of heather drops to its lowest for the year only 53 per cent. ; this is doubtless partly due to the ripening of blaeberries which occurs in this month. The consumption of blaeberry stalks and leaves has risen to 20 per cent., while the quantity of berries eaten is 1 Vide chap, xviii. p. 400. 74 THE GROUSE IN HEALTH AND IN DISEASE shown by the increase of "various" to 27 per cent. The unexpected increase in the consumption of brown winter heather is puzzling, but might be accounted for by an abnormal period of cold weather or blighting wind causing a " set back" in the new growth, and driving the birds to feed more largely on the old shoots. This view is supported by the fact that the birds have also eaten an abnormal quantity of blaeberry stalks and leaves, whereas tional char- i n the following month, when the heather has presumably recovered acter of J July from its temporary blight, the consumption of brown winter heather and blaeberry leaves and stalks drops at once from 47 per cent, to 1 per cent. The figures for July shown in the Table are probably excep- tional, and do not represent the normal proportion of foods eaten in that month ; but they are interesting as showing the elastic manner in which the Grouse can adapt himself to varying conditions. In August the figures for the consumption of heather appear to have become normal, and the fact that this is the great berry month of the year is shown by the increase of "various" to 34 per cent., the largest In August. . . amount in any month. Berry feeding is, of course, irregular, for berries only grow in certain localities, their consumption cannot therefore be gauged by the examination of specimens obtained from moors where no berries Berries* are obtainable. Berries are not an essential item in the diet of the Grouse ; but it is well known that where they are to be obtained Grouse will flock to them in large numbers, often deserting the heather altogether for a while, and congregating in vast packs upon the berry ground. The blaeberry fruit does not as a rule grow in such profusion as that of the clusterberry or Scottish cranberry, and does not seem to be so attractive to the Grouse, though its leaf and bud are much more generally eaten at all times of the year. The August figures are interesting as showing the first indication of heather blossom in the diet. First in the bud, afterwards in full bloom, and lastly in the form of fully ripened seed, the flower of the heather is an flowers important item of food. There is an old saying that when the "stoor" (i.e., pollen dust) is on the heather in August a good Grouse season is sure to follow, and the experience of the Committee tends to confirm this belief. In a year when the bloom is early and luxuriant the pollen rises in clouds when disturbed, covering boots and gaiters with a soft yellowish dust, and sometimes even interfering with the breathing of the dogs. This condition is usually followed by a fine harvest of well-ripened heather seed, and the importance OBSERVATIONS ON THE FOOD OF GROUSE 75 of heather seed as a form of food may be seen at a glance from the figures given in Tables III. and IV. It is often stated that in seasons when the corn has ripened well and early, the stock of Grouse in the following spring is healthy and vigorous, and the breeding season a good one ; from this it has -been argued that the same weather which has resulted in a good crop of grain has also produced A good a good crop of heather seed. This factor too may have something to do with the difference in the numbers of Grouse which moors in different parts of the country are capable of carrying. It is well year- known that the number of Grouse on a moor does not depend upon the area of heather land, for in the thinly-stocked moors of the west of Scotland the heather growth is stronger than in the south of Scotland, where in many districts there is a larger stock of birds. Even in Yorkshire, Lancashire, and Derbyshire the ground does not appear to be better suited for the growth of heather than in Scotland, yet in these counties the stock of district, birds is proportionately much greater. The difference is partly to be accounted for by the fact already noted, that the heather in the north of England is of a better quality, that is to say with many more stalks to the acre, than the rank growth of the west of Scotland, but it has also been suggested that in the former country the normal weather conditions are more favourable to the ripening of the heather seed. Again, in Caithness, where the grain always ripens well on account of the long hours of daylight in the summer months, the stock of birds which the ground can carry is unusually large. In September, October, and November, the tendency to revert gradually from summer to winter diet is well exemplified by the figures in Table III. Throughout these three months the consumption of the heather seed increases steadily, while "various" drops from 16 per cent, in September to 6 per cent, tember, in November. In October we find the item of "brown winter heather" and Nov- ember, reappearing in the list, and in November we have a sudden increase in the consumption of blaeberry stalks and leaves, due probably to some temporary check suffered by the heather similar to that indicated by the figures for July. Turning now to Table IV. (p. 76) we find that in the four winter months the diet becomes more restricted. " Various " practically disappears, and Winter its place is taken by a larger quantity of heather shoots, while heather food ' seeds and blaeberry stalks still keep their place in the list. One or two points are worth noting. In the first place, the sudden drop in 76 THE GROUSE IN HEALTH AND IN DISEASE the consumption of heather seed from 20|- per cent, in January to 2^ per Heather cent - ^ n February and 2^ per cent, in March is interesting as showing eaten n after ^at once tne seec ^ ^ as f a ^ en to tne ground it is no longer eaten by January. G r0 use, though it may be valuable for the reproduction of the plant. TABLE IV. SHOWING THE PERCENTAGES OF VARIOUS FOODS FOUND IN CROP CONTENTS OF GROUSE FROM DECEMBER TO MARCH INCLUSIVE. December January February March Calluna (Heather) shoots Calluna (Heather) seed-heads 59} per cent. \ aK2 27 r 64 percent.) ., so]- r 75ipercent.\ 7a 24 r 97^percent.J 99i (more than J ripe) (more than J ripe) Blaeberry stalks and buds (Vac- cinium myrtillus) 10 per cent. 13 J per cent. 15 Various, including Cowberry leaves ( Vaccinium vitis-idaa), Bog Cranberry leaves (Vac- cinium oxycoccus), Crowberry leaves (Etnpetrum nit/rum), Erica, sorrel, fern, and other green leaves .... 3J 2| 7 * ,, Another point is that both in this and the preceding Table, the figures relating to the consumption of blaeberry stalks and leaves are misleading because they are the result of averaging the crop contents of a large eaten number of birds many of them sent from localities where blaeberry Iftrffdv where pro- is unknown. Were the crops of individual birds recorded it would be found that those coming from moors where blaeberry is common would show almost as large a consumption of that plant as of heather. Blaeberry forms as much as 30 per cent, of all foods taken by Grouse in Derbyshire, 22 per cent, in Yorkshire, and 11 per cent, in Inverness and Dumfriesshire, and very little in any of the other counties. In special cases these averages are departed from, especially when the heather crop has been a failure. Thus some December specimens from Lancashire showed the remarkable average of 80 per cent, of blaeberry stalks and buds, with only 17 per cent, of heather shoots and 2^ per cent, of heather seed, but in this case the heather-seed crop in Lancashire was reported as very bad. In the same year the heather-seed crop in Peebles and Merioneth was reported as exceptionally good, and the December specimens from both these counties showed the pro- portion of 50 per cent, of heather shoots and 50 per cent, of heather seed, but no blaeberry. OBSERVATIONS ON THE FOOD OF GROUSE 77 Probably the consumption of other foods, which are classed under " various," and have already been enumerated, varies in the same way chiefly with local relative abundance, as, for example, in Perthshire, where "various" rises to 53 per cent. ; Ayrshire, where it reaches 47 per cent. ; and Derbyshire, where it reaches 40 per cent, of all foods taken. Individual taste plays a large share in the food statistics of Grouse. One may find, for example, one bird eating largely of fern leaf, another of bog myrtle buds, another of nothing but rush heads or tormentilla seed. In one case, where two birds were killed with a "right and left" in a Grouse drive it was found that one had filled his crop with heather shoots, the other with blaeberry leaf buds, yet both birds had come off the same beat. Occasionally one finds that even an adult bird has eaten scores of small black gnats. The flower of Calluna is varied occasionally by the flower of Erica tetralix, or ripe cluster berries, or spore-capsules of several mosses, or leaves of the cloudberry. The interest of Table IV. centres on the first item, "Heather Shoots," for the figures prove conclusively, if proof were required, that, except on favoured moors where blaeberry abounds, heather shoots and nothing shoots'tke but heather shoots constitute the diet of the Grouse during February and March the fact that the February column shows 7 per cent, of " various " was due to one bird's crop being almost entirely filled with crowberry leaves, a quite unusual diet; the "various" consumed by other specimens examined for that month only amounted to ^ per cent. It is obvious, therefore, that in February, March, and April the question of food becomes a critical one, for if the heather fails the Grouse must suffer either by direct starvation, or what is much more dangerous, by being forced to crowd too closely on to the few small areas where good winter heather is to be obtained. Although we have no evidence from any one of the hundreds of Grouse crops examined that true frosted heather is ever eaten, the heather which actually filled the majority of the winter crops varied greatly in its value as a food. It could often be seen that the birds had been hard put to it to fill their crops at all, perhaps from stress of weather, or possibly because of excessive or deficient burning or an overstock of sheep, or for some other less obvious reason. The mere fact that the crops of many birds contain old heather is enough 78 THE GROUSE IN HEALTH AND IN DISEASE to prove that birds sometimes find great difficulty in collecting a meal of wholesome food. The vast majority of winter crops contain, as we have already said, good dark green or dark reddish brown winter heather, sound wholesome food with a minimum of dead woody tissue. But now and again one finds a crop full of old woody growth of which the food value must be very small. And though the cause of this may sometimes be that the bird is a weakling and has been driven off the better feed to live upon whatever it can find elsewhere, yet this inferior food is sometimes found in the crop of a bird which is evidently no weakling. It may then be due to the fact that the moor has been left long unburned, and that all the heather within reach is old and rank. Or the moor may have been over-burnt from every point of view except that of the grazing tenant. In such a case large tracts of young heather are burned again and again, often by runaway fires, to bring the land to grass and kill the heather. In this the grazing tenants of parts of the borderland and of the north of England have been very successful, and heather in many places is a thing of the past, the moors being now almost all white land. Scattered through this, where the tussocky grass has had its way for many years, is a thin growth of useless straggling heather of little value as food for bird or beast. For the purpose of drawing up Tables III. and IV. two hundred and eighty- seven specimens of Grouse were examined, and the specimens were fairly evenly Tables in. distributed over the months from April 1906 to March 1907. The specimens represented birds from no fewer than twenty-seven different counties, so that the results may be regarded as conclusive, so far as concerns the particular period under review. In case, however, of the period selected being abnormal, Table V. (p. 79) was prepared to show the crop contents for two complete years, viz., 1906 and 1907. In this Table the figures for the corresponding months are placed 1 81 I'll' V i together, and an average is struck for each month. It will be seen that these averages show the same general tendencies as are seen in the former Tables, and confirm the view that the figures given in Table III. for July and November 1906 were abnormal, and probably due to exceptional circumstances. The total number of specimens examined for the purpose of drawing up Table V. was four hundred and thirty-six, including the two hundred and eighty- seven already included in Tables III. and IV. ; but in 1907 specimens were OBSERVATIONS ON THE FOOD OF GROUSE 79 not quite so well distributed as in the earlier period. This remark specially applies to May, June, and July 1907, when only one specimen was received for each month as against a monthly average of fifteen in 1906. TABLE V. COMPARISON OF MONTHLY AVERAGES OF CROP CONTENTS COVERING Two YEARS. Jan. Feb. Mar. Apr. May. Juu. July. Aug. Sept. Oct. Nov. Dec. 1 1906 64 75* 97 93 81* 82 53 60* 63J 42 39 54 Calluna heather shoots . . . < 1907 89 72 81 64 100 100 95 38 63 51 70* 591 I Av. 76* 73| 89 78* 90| 91 74 49| 631 46* 54| 56J ( 1906 20| 4 2t * 6* 16* 28 33 23 Calluna heather flower and seed- j 1907 10 9 2 14 21 24 19* 27 l J S Av. 154 5} 8* i 9f 188 26 26| 25 ( 1906 13| 15 4 6 6 20 4*. 9 22 21 Blaeberry stalk, bud, and leaf . . < 1907 i 19 15 21 12 1 10 10 I Av. 17 7* 12* 3 3 10 6 2i 5 16 15* t 1906 2* 7 1 3 12 12 27 34 11 21 6 2 Various . . . . . . < 1907 i 2 15 5 36 16 24 3* I Av. i* 3* H 9 6 6 16 35 13* 22* 3 21 The results of this Table have also been given in the form of a chart for purposes of comparison. 1 The strain upon the vitality of the Grouse in the winter months is intensified by the fact that a greater bulk of food is required by ' * More food each bird per day than is required during the summer. required , in winter But few would have rated it at five times the value, and yet, than in from a comparison of the afternoon crops of the winter with those of the summer, this appears to be the case. Thus the average weight of food found in a Grouse crop from December to March, between 3 P.M. and 6 P.M., is 250 grains, whereas the average weight of food found in a Grouse crop from April to November, between 3 P.M. and 6 P.M., is only 50 grains. The fact that more food is required in winter to maintain the body temperature would, of course, partly account for this increase, even Reasons if the heather had the same food - value. But as heather certainly for thls ' has an inferior food - value in winter, the amount taken must be increased 1 Ftrfep. 80. 80 THE GROUSE IN HEALTH AND IN DISEASE CHART SHEWING PERCENTAGE CONSUMPTION OF VARIOUS FOODS EATEN EACH MONTH BY THE RED GROUSE 100 95 30 86 80 75 70 65 60 & 50 15 10 35 JO 25 20 15 10 5 JANUARy FEBRUARY MARCH _i E Q. < | Ul z 3 -D >i ^ "3 AUGUST ULJ CO UJ t Q. UJ o OCTOBER NOVEMBEI? DECEMBER HEATHER TOPS. (Ca//una vu/gar/sj HEATHER FWW/t AND SEEDHEADS (Cal/una va/garis) BLAEBERRY STEM AND BUD (Vaccinium qyrtillus) VARIOUS. 90*, -9t 89 A \ / ( \/ \ 76% / 7&'/z 5 r ^/ 73% 74- \ / \ \ I 6J% / l\ /\ / J>6% V \ ^ 51W 39% T7 ^^ K :\ . * 26- -263/1. '**?'> t * . / '2^2 \ \ I5''e 17 /\ /6 *'18 S / B /, .' : * * IS,. f >/5^ \ ^, f / \ \j 12% X\ ' (0 / / ' /J^ 1 t X A \ \ \ \.' 5% \ s** V 7 :> ' ;$... ,./ r- / 9* A / / J- "/%''' >3'4.. ^ "-ft N J._. -^f- -j-' =fl_ / X ( N 2**' ^ ^ * J... 2K>. OBSERVATIONS ON THE FOOD OF GROUSE 81 in a far greater proportion. No doubt the necessity for provision during the longer hours of night-time has some effect in the overfilling of the crop in winter, but this would not account for crops being heavier in March, when the days are comparatively long, than in November when they are short. The interesting fact remains, and is amply proved by the figures, that more food is required by the Grouse in winter than in other seasons of the year ; and as in winter the proportion of Calluna to all other foods is as seven to one, it is obvious that a very great advantage accrues to a Grouse on a moor in which young and comparatively nourishing heather is abundant during the winter months, i.e., on a well-burned moor, well covered with young heather of a varying number of seasons' growth. To put this conclusion in other words ; whereas in summer a certain area of heather will support a bird comfortably, many times this area will be required for the same bird in the winter, so that the capacity of a moor, as regards the question of stock, must be gauged mainly by its Grouse-feeding value during the winter months. If we consider this generalisation with reference to moor management we shall see that a moor carrying its full tale of birds in the summer becomes automatically and unavoidably overstocked in the winter unless the stock is heavily reduced by shooting, for not only is there less food available, but the birds require a much larger quantity of food to keep them in health. Migration of birds in winter obviously complicates the question. In the case of a moor on high ground, which often loses all its birds in winter, probably natural conditions regulate the stock of birds automatically Effect of during spring and summer. But on the adjacent low-lying moors mi s ratlon - the case is more serious ; for the ground has to supply not only more food than is needed for its own stock in summer, but in addition an increased seasonal demand made upon it during the winter months by hundreds of undesirable immigrants from the higher ground. Such low-lying moors must always run the risk of being dangerously overstocked in the winter. In certain parts of the country oats form a regular seasonal change in the dietary of Grouse, and this form of food must now be considered. 1 Very few birds with corn in any part of the alimentary canal were submitted for examination ; but so far as these specimens show, oats are an unsuitable form of food for Grouse. As is well known, Grouse often visit the 1 Vide also chap i. p. 25, and chap. viii. pp. 178-180. VOL. I. F 82 THE GROUSE IN HEALTH AND IN DISEASE stubbles and corn-stooks in very large packs in the autumn in September, October, or November, according to the season and locality. They seem to know that they are out of place, and finding themselves with a wealth of food all round, away from their normal surroundings, are eager to fill themselves as full as possible in a very short space of time, aware, by instinct or experience, that they may be disturbed at any moment. One consequence is, as the examination of birds has shown, that they eat as much husk as grain, instead of picking and choosing as Partridges do, in a quiet and leisurely manner. This difference in the crops of Grouse and Partridges that have been feeding on the same ground is very noticeable. The one is filled to repletion with indigestible and exceedingly irritating husks and a compara- tively small amount of grain, while the other (the Partridge's crop) contains grain only. The result in the Grouse is that the whole alimentary canal, from one end to the other, is soon in an irritable and inflamed condition. The gizzard does what it can to work up the husks and grain into a milky paste, but the microscope shows that this paste is to a large extent composed of siliceous spicules and small spines of an almost glassy hardness. This damages the delicate mucous lining of the intestine. The result of the passage of this irritating food is, first, an extra flow of digestive juices, secondly, an increased activity on the part of the walls of the intestine, both as to movement (peristalsis) and secretion from the stimulation produced by this form of food. Thirdly, comes a point at which mucus is thrown out in large quantities to protect the gut, and this continues and increases until the actual cells them- selves are shed, and the protection breaks down. Finally, the intestine becomes inflamed to the extent of ulceration, and this state will continue and increase so long as the cause continues to act. Such irritation to the intestine of even a healthy Grouse, which already has to deal with worms of at least two kinds, is bound to have an evil effect if continued for any length of time ; moreover, in places where the corn is left out owing to bad weather, or for other reasons, there is the additional aggravation that the birds may be filling themselves with wet and sour grain, not one whit the less irritating as regards the husk, which cannot be softened by wet ; and no doubt the consequence of this is in some seasons noticeably bad. Corn in moderation is probably not unwholesome as a food, and were it OBSERVATIONS ON THE FOOD OF GROUSE 83 possible to feed one set of Grouse with clean grain, and another with such stuff as the birds pick up for themselves on the stubbles, there is no doubt that the former would rapidly improve in condition, and the latter go steadily downhill. Such an experiment is not practicable. To recapitulate, the following may be given as a fairly accurate account of the monthly dietary of the Red Grouse for the year : January, Calluna shoots (64 per cent.) and Calluna seed -heads (27 per cent.). February, Calluna shoots (75 per cent.) and the stalks and buds of blaeberry and leaves of cowberry. March, Calluna shoots (97 per cent.) and blaeberry stalks and buds. April, Calluna shoots (93 per cent.) and very little besides. May, Calluna shoots (82 per cent.) and rather more "various." June, Calluna shoots (82 per cent.) and "various." July, Calluna shoots (53 per cent.) and an increasing amount of " various." August, Calluna shoots (60 per cent.) and some Calluna flowers aud " various." September, Calluna shoots (63 per cent.) and 16 per cent, of Calluna flowers and " various." October, much less (42 per cent.) of Calluna shoots, and nearly 30 per cent, of Calluna flowers, and some " various." November, still less (39 per cent.) of Calluna shoots, and 33 per cent, of Calluna flowers and seed-heads, and the rest " various." December, a rise in Calluna shoots to 60 per cent., but still 27 per cent, of Calluna seed-heads. LIST OF VEGETABLE FOOD EATEN FROM TIME TO TIME BY THE RED GROUSE Calluna vulgaris, the staple food of Grouse, is known generally as Heather. Grouse eat the shoots, flowers, and seed - heads. See PI. xxiii., p. 71. Vaccinium myrtillus, Blaeberry, Blueberry, or Blue Whortleberry. Grouse eat the stem, buds, flowers, and berries. See PI. xxiv., p. 86, Fig. 1. 84 THE GROUSE IN HEALTH AND IN DISEASE Vaccinium oxycoccus, Bog Cranberry. The leaf and the berry are sometimes eaten. See PI. xxiv., p. 86, Fig. 2. Vaccinium vitis-idaa, Red Whortleberry, Clusterberry, and (in Scotland) Cranberry. Leaf and berry are eaten. See PI. xxiv., p. 86, Fig. 3. Arctostaphylos uva-ursi, Red Bear Berry. See PI. xxiv., p. 86, Fig. 4. Rubus chamamorus, Cloudberry, or (in Cumberland) Noops. The leaf is eaten, and so are the berries. See PI. xxv., p. 87, Fig. 1. Empetrum nigrum, Crowberry, Crakeberry or Lingberry. The top shoots, tight leaf buds, and berries are eaten. See PI. xxv., p. 87, Fig. 2. Erica cinerea, Purple Bell Heather. The flower alone is eaten, but while it is out it is eaten in fair quantities. See PI. xxv., p. 87, Fig. 3. Erica tetralix, Cross-leaved Heath. Flower-heads are eaten in quantities, but leaf-shoots are avoided. See PI. xxv., p. 87, Fig. 4. Salix repens, Dwarf or Creeping Willow, a low, straggling shrub from 2 inches to 1 foot in height. Foliage and young shoots more or less silky white. The plant has small oblong leaves, and bears small catkins in spring, followed by silky seed vessels. Found on sandy ground. Where it occurs the leaves and young shoots are greedily eaten. Myrica gale, Bog Myrtle, or Sweet Gale, an erect shrub, 2 or 3 feet high, fragrant when rubbed. It has long, narrowish pointed leaves, slightly toothed near the tip, and often downy beneath. It bears small catkins before the leaves are out. Always found in boggy places. The buds are eaten in winter and early spring, but sparely. Eriophomm, Cottonsedge or " Cotton Grass," two or three species of similar habit. A rush-like plant, bearing in summer, after the flowering period, conspicuous, white, cottony tufts, either solitary or in clusters of two or three or more. Grouse are very greedy for the flower of this plant in spring, and the tender shoots are also said to be useful when they first appear. The plant is then known by gamekeepers as "Blackhead" or "Mosscrop." It is found in marshy ground. Rumex acetosella, Common Red or " Sheep " Sorrel. A slender plant, from 3 or 4 inches to 1 foot high, often turning red. It has long, more or less arrow-shaped leaves, very acid to the taste. The OBSERVATIONS ON THE FOOD OF GROUSE 85 red-tinged green flowers are in terminal clusters on an erect stem, and are seen from spring to autumn. The plant grows in dry pastures, and on open heaths. The seeds are greedily eaten. Juncus squarrosus, Heath Rush, a small rush about a foot high, growing in drier situations than most rushes. The flower- and seed-heads are very freely eaten. Luzula campestris, Field Wood Rush, a small rush with soft, flat, grass-like leaves, fringed with silky hairs. It grows in dry places. The flower- and seed-heads are eaten. The following additional list of plants, upon which Grouse are said to feed, is given in a pamphlet on " The Improvement of Grouse Moors," by the Rev. E. A. Woodruffe Peacock, who has examined the contents of many crops and gizzards of the Grouse. PotentiUa tovmentilla, Tormentil. Trifolium minus, Suckling Clover. Galium saxatile, Heath Bed -straw. Pedicularis palustris, Marsh Lousewort. Pedicularis sylvatica, Heath Lousewort. The seeds of the following plants are greedily eaten, and are most useful as late autumn and winter food : Alopecurus myosuriodes, Mouse-tail Grass. Molinea ccendea, Purple Melio Grass. Atnplex patula, Common Orache. Cerastium triviale, Chickweeds and other moor cerastia. Polygonum aviculare, and P. persicaria, Persicaria, and Knot Grasses of all species. The flower-heads are also eaten. Viola lutea, Yellow Violet. Pteris aquilina, Bracken Fern. In their season, too, Grouse are very fond of capsules of the moor mosses, such as the Great Golden Maidenhair Moss (Polytrichum commune), and the smaller fungi. For the purpose of reference the following plates and detailed descriptions are given of some of the moor plants most commonly confused on account of the variety of names by which they are known. 86 THE GROUSE IN HEALTH AND IN DISEASE PLATE XXIV FIG. l The BLAEBERRY (Vacciniurn myrtillus), known also as the Whortleberry, Bilberry, Whinberry, Blueberry, or " Whorts " in various districts, a low branched shrub 6 to 18 in. high, growing often in large green patches. The flowers, which appear in April, May, or June, are flesh-coloured, and the berries, which are black with a purple bloom, ripen in July and August ; they are agreeable to the taste. FIG. 2 The CRANBERRY (Vaccinium oxycoccos), known also as the Bog Cranberry, Mossberry, Moorberry, or Fenberry, a very low plant with a prostrate, straggling, slender stem and small leaves. It is found creeping on the surface of the moss in boggy places. The flowers, which appear in June, July, or August, are solitary and bright red, and the dark red fruit is pleasant to the taste. This berry is common in many parts of England, but is little known in Scotland though the plant without the berry is sometimes seen. The berry ripens in August. FIG. 3 The RED WHORTLEBERRY or CRANBERRY (Scotland) (Vaccinium vitis idcea), also called Clusterberry, Cowberry, Nutberry or Nubberry, Craneberry and Crawberry, a low straggling shrub with leaves resembling those of the box. The pink flowers are in terminal drooping clusters, and the berries are red. It flowers between June and August, and the berries ripen in September. Its leaves are to be distinguished from those of Arctostaphylos uva-uni by the dots on the under surface and the rolled-back margins. FIG. 4 The RED BEAR BERRY (Arctostaphylos uva-urri), also called Grassack or Graashacks, a small trailing evergreen shrub which grows in dry heathy and rocky places. The leaves are finely reticulated, and the berries are red and mealy, with hard angular seeds. The rose-coloured flowers appear from June to August in terminal clusters PLATE XXIV. FIG. 1. r. G. M. iiiyrtt-lltu (Blaeberry Whortleberry Bilbcrry- Whorts Whinberry). C. G. M. FIG. 2. yaccinium oxycoccos (Cranberry Mossberry). C. c. M. FIG. 3. yaccinium vitis fdcsa, (Red Whortleberry Clusterberry). Cranberry (Scot.) FIG. 4. Anlostaphylos uvn-ursi (Red Bear Berry Graashacks). i. 86.] PLATE XXV. C. G. M. FIG. 5. fiubus chauuKiiwrus (Cloudberry Averine). C. G. M. FIG. 6. Empetmm nicjrwn (Crowberry Crakeberry). C. G. M. FIG. 7. ^rt'oa cincrca (Bell Heather Fine-leaved Heath). 8. Erica telralix (Cross-leaved Heath). Opposite p. 87. ] OBSERVATIONS ON THE FOOD OF GROUSE 87 PLATE XXV FIG. 1 The CLOUDBERRY or AVERINE (Rubus chamce- monis), a small herbaceous plant belonging to the Raspberry family with large green leaves growing among the heather on the mountain tops. It has large white or rose-coloured flowers, which appear in June and July, and the bramble-like fruit is orange yellow. FIG. 2 The CROWBERRY (Empetrum nigrum), Crakeberry, Lingberry or Blackberried Heath, a small prostrate plant with the habits of a heath. The purplish flowers, which appear in May and June, are very small, and are placed in the axils of the upper leaves. The ripened berries are black. FIG. 3 BEI.L HEATHER or FINE-LEAVED HEATH (Erica cinerea) has leaves three in a whorl. It grows on dry places and similar situations to common heather. The flower-bells are purple. The taste of the leaves is more bitter than that of common heather. It flowers in July and August, appearing before the common heather. FIG. 4 CROSS-LEAVED HEATH (Erica tetralix) has leaves four in a whorl and placed crosswise. It has rose- coloured flowers, and grows in similar situations to common heather. Flowers in July and August. Grouse do not seem to care much for the two last-named heaths. 88 THE GROUSE IN HEALTH AND IN DISEASE PART II. THE INSECT FOOD OF YOUNG GROUSE BASED ON AN EXAMINATION OF CROPS AND GIZZARDS By Percy H. Grimshaiv The Committee have devoted special attention to the question of the food of the Grouse in the earlier stages of its existence, and have examined the crop Variety of contents of many chicks with a view to ascertaining the nature of their chicks' diet. ^jgj. Their dietary is extraordinarily varied, and probably we have as yet by no means exhausted the list of what they eat. It was observed from insect food the commencement of these investigations that young Grouse were common. mucn m0 re addicted to insect food than were the adult birds, and in order to complete the Committee's knowledge on the subject it was found advisable to obtain the services of an entomologist. In the months of June and July 1908 the moors in Inverness-shire, Morayshire, and Banffshire and at a later period also in Yorkshire, were visited with the object of investigating the food of the young Grouse. (1) In the first place it was desirable that a number of young Grouse chicks should be obtained, and the contents of their crops and gizzards examined, with a view of ascertaining both the nature of their food, and also, if possible, the intermediate host (supposed to be some insect or mollusc) of the Cestode parasites which infest these birds. (2) To exactly determine the various fragments found in the crop, pro- ventriculus, and gizzard of Grouse by the careful collecting of insects on the feeding grounds of the young birds. In many cases the remains in the crop or intestine were so broken up and crushed that it was only possible to determine and name them by careful comparison with whole specimens obtained on the same spot. 1 (3) To collect and put into spirit large numbers of insects and spiders for the purpose of dissection and microscopic examination for possible cysts of tapeworms. The list of insects collected was most interesting, and included many rare 1 A complete list of the insects obtained on the moors during the course of this Inquiry has been published in the "Annals of Scottish Natural History," pp. 150-162, July 1910. THE INSECT FOOD OF YOUNG GROUSE 89 species. Unfortunately, owing to broken weather, working with the net was only possible on six days, otherwise the list would have been even L istsof more representative. Most of the specimens were collected on the msects - actual feeding grounds of the young Grouse, and the list is therefore useful as showing the variety of diet possible during the first fortnight or so of the chick's life. On a typical Grouse moor by far the greatest variety of insect-life is found in the marshy ground around the sources of the streams. In every such place the entomologist, by using the sweeping net, finds an abundance of specimens and a fair variety of species. Diptera largely preponderate, but small Tineid Moths, May-flies, Stone-flies, and Spiders are also plentiful. On the higher and drier ground many other insects occur, including Crane-flies, Bees, and the larger Lepidoptera, as well as a few others which must be regarded as of mere casual occurrence, such as Syrphidce or Hover-flies, the Bomlws or Humble- bee, etc. In Appendix E will be found a detailed list of the contents of the crops and gizzards of forty - five chicks examined. The birds were captured by hand and immediately killed by chloroform, dissected the same day, and their crops and gizzards transferred to methylated spirit. The contents of both crops and gizzards were afterwards examined, and the fragments carefully compared with whole pinned insects obtained on the same ground as the chicks. In many cases the remains were so crushed and fragmentary that it was impossible to ascertain their nature, beyond the fact that they were Coleopterous, Dipterous, etc. Where the generic and specific names are both given, it may be assumed that the identification is certain. The commonest insects in the crops are undoubtedly Diptera of the family Limnobiidffi. Seventeen crops contained specimens that could be referred to this family, and of these no fewer than fourteen contained the curious Insects little species known as Molophilus ater. In one case (that ticketed ^cmiy " 1 " Moor, No. 2-22) there were over one hundred specimens of this fly. eaten - According to Dr Wilson's estimate this bird would be from eighteen to twenty days old, and its crop was gorged with the remains of Molophilus ater, and contained also two other Limnobiids, besides a few tips of heather. Other crops from the same moor, belonging to chicks a week old or less, contained fifty-six, fifty, thirty-four, and eleven examples respectively of the same fly. 90 THE GROUSE IN HEALTH AND IN DISEASE We may therefore conclude that the species is attractive to the eye and taste of the young chick. It was found plentifully in certain marshy spots where the chicks were known to feed. Although the results have been tabulated in various ways, it has been found difficult to trace any outstanding feature regarding the insect food of Grouse chicks. With such a small number of birds it would be manifestly unwise to work out averages and curves. It is sufficient for the present purpose to show that the food of young Grouse is largely made up of insects, that these insects present a great variety of species, and that the species most commonly found in the crop is probably that which is most numerous in the area where the chicks are accustomed to feed. But it is also evident insect food ^ na ^ the number of insects eaten shows a considerable falling off afteVthird towards the third week of the chick's life. We should not expect the chicks to show much discrimination in the catching of their prey, and as Diptera undoubtedly are the most numerous in individuals of all the insects on the moors, it naturally follows that they head the list in the table of crop contents. In the Table (p. 91) an attempt has been made to indicate, in somewhat more graphic form, the results of the examination of the crop contents. The crops are arranged, so far as possible, in order of age, beginning with the youngest. The ages of the birds are estimated by the length of the keel of the sternum or breast-bone. Relatively the ages are believed to be sub- stantially correct, though individually there may be a discrepancy of three or four days. The sign x in the Table indicates the presence of remains in the crop belonging to the order of insects named at the top of the column. In the third column the solid black o shows that no insect remains of any kind were found. This Table is of special importance as showing the extent to which the insect food falls off after the second week of life. This is also borne out by the great drop in the number of orders of insects represented by the crosses. The crops of young chicks in the first week or two have been found to contain, in addition to insects, the following vegetable food-stuffs in Vegetable food of varying proportions : Calluna shoots ; only the very fresh young green shoots are eaten. Calluna flowers, in full bloom, and flower-buds. THE INSECT FOOD OF YOUNG GROUSE 91 TABLE SHOWING PROPORTIONS OF ANIMAL AND VEGETABLE FOOD EATEN BY YOUNG GROUSE. 'o 1 V Keel of Sternum in millimeters. Insects present x, or absent o. INSECT FOOD. Age Estimate. | VEGETABLE FOOD AND OBIT. I 5 Coleoptera. 1 I n Neuroptera. Aracbnida. Hemiptera. Lepidoptera. 1 Heather (Calluna). Juncus & Moss. Bracken. Vaccinium. 3 6 ll s ^ a i & J 3 D. 10 D.21\ D.12 1 D. 23 I T. I/ D. 16 T. 2\ D.26/ D. 15 T. 3 D. 181 D. 24 1 D.13J D.20 9-75 10-50 10-75 11-00 11-25 12-00 12-25 13-00 13-25 O G (I [1 X J x \l X 1st week 1 to 7 days old X X X X X X X X X X X X X X X X . X X X X X . . . X X X X X X X X X . . X . X D. 9) D. 5f D. 4 D. 14 \ D. 19 / D. 2) D. 3f D. 7} D. li D.25J T. 4) D.17/ 13-50 14-50 15-00 15-25 15-50 15-75 (I X ! x lx f u B X X X X X X X X X X X X X X X 7 to 18 days old X X X X X X X X X X X X X X X X X X X X X X X X X X . X X T. 12 D. 2 B. 31 T. 5/ 16-00 16-50 17-25 o X ! lo 18 to 20 days old X X X X X . . X . X T. 9 T. 10\ T. 8 I D. 81 T. 7J T. 6 20-75 22-75 24-75 26-75 o (I (I X X X X X X X X X X 20 to 28 days old X X X X X X X X X X X X X X . B. 6 T. 11 E. 1 B. 2 B. S 27-75 28-25 30-00 X o X X X 28 to 30 days old X X X 34-00 35-50 X X X X 35 to 40 X X X days old B. 4 36-50 X X - 6 weeks B. 1 44-00 1 X X X 6 to 7 weeks X X 92 THE GROUSE IN HEALTH AND IN DISEASE Moss fruit-capsules, or spore cases. Blaeberry flower - buds, and ripe blaeberries occasionally ( Vac- cinium myrtillus). Blaeberry leaves and young stalks. Fern leaves (Blechnum and Ptens). Rush heads, in flower and seed (Juncus sq.). Tormentilla seed-heads. Shoots of Empetrum nigrum. Of these the most constant are the fresh young shoots of Calluna ; then the fresh blossoms of Calluna, and then the spore capsules of moss. While insects are commonly eaten, many crops of the youngest chickens contained no trace of them. It is practically certain that by eating some such animal food the cystic stages of the intestinaleworms which infest young birds even in the first weeks of their existence are introduced. Until this matter has been further investigated, it is needless to say more here. PART III. WATER By A. S. Leslie There are various opinions regarding the Grouse's requirements in the way of water. The majority of moor-owners and naturalists are firmly convinced that Grouse do drink, and quote in support of their view the undoubted believed f ac t that when springs and drains are periodically cleared the stock is that Grouse r ' drink more healthy and numerous. Others state that water is not necessary, water. and that the fact that drains and springs are not allowed to become choked may have beneficial results apart altogether from the maintenance of the water supply. The evidence on the subject is somewhat conflicting. As already stated, Grouse do not appear to require water from springs or burns in the earlier stages of their life ; 1 this fact is established from observations on both wild and hand-reared birds. On this subject, a well-known moor- owner in BanfFshire writes : " Grouse never seem to want water except in a very dry season ; a shower is sufficient to last them for a long time. The less water they have in hand rearing, I find, the better they do." And, again, " I have never noticed that the young Grouse, when half-grown or older, 1 Vide chap. ii. p. 18. WATER 93 require more water than what they pick up in the grass in wet weather, and what is sprinkled on the grass or heather at meal times in dry weather. Old Grouse seem to know how much is good for them ; while young Grouse, if allowed access to water, are almost certain to drink too much, and scour. This, of course, refers to tame birds." Another correspondent of the Committee, a gamekeeper near Pitlochry in Perthshire, writes : " Regarding water, I have known several broods fetched out 600 yards from the nearest water of any kind, in a dry season, and they continued to thrive without water for at least three weeks after hatching, when rain would no doubt relieve the old bird, which I am of opinion had nothing to drink but dew all that time ; at least I never found young chicks without the parent bird along with them." On the other hand, a gentleman in Yorkshire, who successfully reared twenty-four Grouse out of twenty-eight eggs set, says: "They were watered three times a day." And a gamekeeper, whose experience of some of the largest moors in Perthshire has lasted for a lifetime, says: "There must be water, and, where a moor is blest with good springs, there will the Grouse be also. One cannot have too many springs on a moor in dry weather." When full-grown there is little doubt that Grouse do drink ; hand-reared birds are seen to drink frequently on a hot day from the supply of fresh water provided for them, and the droppings of nesting birds are always found Evidence near water. Wild birds, in the hot weather of July and August, and in j," a^se the dry, frosty days of winter, often congregate near running water and drmkm g- open streams when other drinking-places are dried up or frozen hard. It is well known that in the summer Grouse often shift entirely from the drier beats of a moor to the well-watered ones, and, on a certain dry, sandy moor near the sea, the young birds die if the artificial drinking- pools are allowed to run dry. The almost unanimous opinion expressed by correspondents favours the view that under natural conditions the adult Grouse go to drink two or three times a day. In support of the view that Grouse either never drink, or at least are not dependent upon a supply of drinking water, several arguments are brought forward. It is said that no Grouse has ever been seen to drink, but Arguments when we consider how wild the bird is in its natural state this is not Arouse do surprising; indeed, only very few observers have succeeded in seeing notdrink - the bird in the act of feeding. Another argument used is that from an examina- tion of the alimentary canal no trace of water can be found, and the contents 94 THE GROUSE IN HEALTH AND IN DISEASE of the crop are always found to be dry. This may be sufficient to prove that the bird does not drink when the crop is full, but does not dispose of the possibility of its drinking during the long periods of the day when the crop is empty. Then, again, cases are quoted of moors which carry a large and flourishing stock of Grouse where the ground is by no means well watered. On one of the best stocked Grouse moors in Britain, the only water comes from about a dozen springs and one deep burn which runs through the middle of the ground. Grouse are seldom observed to resort to the burn, and it is difficult to see how several thousand birds can all water at the springs. While it cannot be said that this entirely disposes of the water drinking theory, it seems to justify the view that Grouse are not dependent upon a large water supply. How far dew forms a substitute for water is a matter which the Committee consider of great importance, and one to which they have given considerable attention without arriving at any results sufficiently definite to be worth reporting. There is a curious lack of information available regarding the fall of dew, the districts in which dew is most prevalent, etc. There is probably a close connection between dew and the infection of Grouse by the nematode worm Trichostrongylus pergracilis. In view of the fact that the larvae of this worm can only climb the heather shoots, or indeed exist on them, when they are slightly damp, the Committee believe that this is one of the questions which might be further investigated with advantage. 1 PART IV. GRIT By Dr H. Hammond Smith and R. H. Rastall The health of Grouse and of other game-birds is greatly dependent on the nature of the grit they take to assist in the assimilation of their food. Necessity During the autumn of 1906 the Committee made a collection of the of grit, grits from the gizzards of Grouse and other game-birds. This collection formed the subject of a paper read by Dr Hammond Smith at Collection a meeting of the Zoological Society in May 1907. These grits were Com 6 by obtained from the gizzards of Ptarmigan from Ben Mohr in Sutherland- mittee. shire ; Grouse from Ross-shire, Inverness-shire, Aberdeenshire, and 1 Vide chap. x. pp. 228, 233. GRIT 95 North Wales ; Blackgame from Koss-shire and Exmoor ; and Partridges and Pheasants from various counties in England and Scotland. The gizzards of Grouse naturally received most attention ; but for purposes of comparison those of other game-birds were also examined. The quantity of grit found in a single gizzard varies very slightly. Samples taken Bulk of from adult cocks were each found to be equal in bulk to an ounce of f^ 1 ( ! a f ( ^ md shot, although, of course, much lighter, and the number of grains in s izzard - each ranged from three hundred and fifty to five hundred and fifty. It was also noticed that, especially in the case of Pheasants, the cock birds have a larger quantity of gritty material, while the individual grains also appear to be larger. This is doubtless correlated with the larger size of the si zeo f grit bird, for in the smaller varieties of game - birds and in immature P artlcles - individuals it is invariably found that the grains of grit are fewer and smaller than in the larger and full-grown specimens. The gizzard of a chick of fourteen to twenty days old was examined, and the grit was found \v e i g htof to weigh 3 grains. It consisted of fragments of quartz, smooth grits- and water-worn, and evidently picked up in the bed of a stream. Two only were minute but perfect prisms of quartz, quite unworn. All the grains were decidedly smaller than in an adult. In a half-grown chick the grit weighed 58 grains, while in adults the average weight is 118 to 120 grains. Grits are present even in very young birds ; in one case they were found in a chick only forty-eight hours old. The grit of an old bird can be at once recognised by the large size of the grains, and by the excessive polish and smoothness of the well-worn surfaces, suggesting that the larger grains are in use for a considerable period of time. Between extreme youth and old age all stages of wear and polish may be found as well as every gradation in point of size. A full analysis of the petrological character of the specimens is contained in the Interim Report of the Committee ; it is unnecessary to repeat all the details here, but a short summary of the general conclusions may c onst j tu _ be given. As would naturally be expected the constituents of these entsof grit- samples are nearly always hard rocks and minerals. Minerals or rocks softer than quartz, flint, or felspar are hardly ever found ; this may be due partly to selection by the bird, but it must also be borne in mind that soft substances would soon be ground up by the action of the gizzard, and disappear. To this also is probably due the almost complete absence of any calcareous matter, 96 THE GROUSE IN HEALTH AND IN DISEASE which is both soft and comparatively soluble. The only really abundant constituents in the gizzards of Grouse are quartz and felspar, and small fragments of various rocks composed of one or both of these minerals, such as granite, gneiss, quartzite, etc., with occasionally grains of shot and crystals of garnet, and other minerals. Felspar is chiefly found in specimens from Scotland and North Wales, where rocks consisting largely of this mineral are specially abundant. The specimens from Ross-shire are of interest from the geological point of view, since in some cases they contain a representative collection of the gneissose and schistose rocks of the north-west Highlands. A comparison of results shows that in the gizzards of Grouse quartz is nearly always present, although no quartz may be found on the moor where the bird was shot. Two cases of this may be mentioned. On one part of an exten- sive shooting in North Wales there is excellent feeding and sheltering ground for Grouse, but no quartz grit, yet the gizzards of the birds always contain quartz ; in order to obtain it they have to fly across a wide valley Resent in * an ther hill, and then return again to their feeding - ground. fhou"h S not Again, on a Ross-shire moor no quartz could be seen on the moor, found on y e a \i the gizzards of these birds contained quartz; it was found that this quartz was probably obtained from the burns, for on examining them small pockets of water-worn quartz were found in many of the pools and eddies. The quartz is not always angular and sharp, but is frequently water-worn ; in these cases it is probably picked up out of burns in fact, in low-lying moors the water-courses are almost sure to be the source of this quartz. The grits found in the gizzards of Yorkshire Grouse are very similar to those of the Scotch birds except in one case, where the grit is chiefly composed of small black pebbles. In one gizzard out of every three of the Grouse examined shot were found ; but shot were rarely found in the gizzards of Pheasants. The mineral contents of the gizzards are very fairly representative of the harder rocks and minerals of the district from which each is derived, but it may be noted that whereas Ptarmigan and Grouse seem and unable to exist without quartz, Partridges, and still more Pheasants, are more adaptable ; they prefer quartz if they can get it, but failing quartz, Pheasants will content themselves with flint, sandstone, and even coal. Doubtless the tough and fibrous nature of the food eaten by Grouse GRIT 97 makes it necessary for him to confine himself to the hardest and most angular descriptions of rock, and even when quartz grits are found in the gizzard the angles are often rounded and smooth from the nature of the work which they have been called on to perform. Flint grit may serve for Pheasants, but it does not fracture into serviceable shapes for Grouse. Sharp points and cutting edges are not wanted, but sub-angular and roughly rounded pebbles of small size for the breaking up and pulping of the comparatively hard foliage of Calluna. In another part of this Report it is suggested that when quartz is scarce it might be artificially introduced with a view to the welfare of the stock. This expedient has met with some success, but has not been very extensively adopted. The artificial introduction of quartz grit has frequently been tried with Pheasants, and always with success. In the grit- Committee's collection there are several specimens of gizzards from Pheasants shot on estates both before and after the introduction of quartz, and in every instance it can be seen that the quartz is preferred to the natural grit found on the estate. Observations have been made with a view to finding out how long quartz or other hard grits normally remain in the gizzard of a Grouse, and it has now been proved by experiment that if none are supplied to make good the normal and presumably accidental loss, the bird whose dunng gizzard may on the first day have allowed about a hundred grits to grits pass, becomes exceedingly careful on the second and third day, and in the gizzard. allows no such loss to occur again. In a case m which no grits were supplied to a Grouse at all, and in which the grits passed in the droppings were carefully washed out and collected every day for twenty-one days, the greatest daily loss after the second day never exceeded thirteen small pieces, even though a hundred and sixty pieces had been passed on the first day, and twenty-seven pieces on the second. This bird died unexpectedly on the twenty-first day, and upon dissection the gizzard was found to Control contain still no less than half of the original contents, all of which over waste of grits. had been in the gizzard for at least three weeks. That this apparent control of the gizzard over the loss of grits was not merely accidental was proved by the occurrence of a precisely similar series of losses day by day in another bird ; but when its companion died, apparently as the result of losing half its grits, the second bird was not pressed to a similar finish. 1 It is therefore probable that in the ordinary course of a Grouse's life the 1 For detailed description of experiments in Grit Starvation, see vol. ii. Appendix F., part (1). VOL. I. G r 98 THE GROUSE IN HEALTH AND IN DISEASE daily loss of small grits is considerable, and that this loss is replaced by an equally regular supply picked up day by day upon the sides of moor roads, or in " scrapes," or along the channel of a burn. But, in the event of a heavy snowfall it appears very probable that the Control Grouse soon recognise that the loss is exceeding the amount which tirmTof 11 can be ma de good day by day, and that in such a case they can, in some unexplained way, place a check upon further loss. It cannot for a moment be imagined that the bird has any sort of voluntary control over the passage of grits from the gizzard. But it is quite conceivable that the gizzard itself will allow a certain careless loss of any surplus number, especially of the smaller pieces, so long as there is still a sufficiency of larger grits in the gizzard. When the supply, however, is straitened, and the bird fails to find more grits to swallow, it may be that less food is eaten as well, and thus the loss of grits is automatically reduced. This is probably the explanation which comes nearest to the truth, and it is a significant fact that a bird not only loses weight, but may actually die when only half of its normal supply of gizzard grits has been lost, and when the dejecta show that this amount of grit is still capable of grinding up the food given to it. Under normal conditions the character of the grit required differs with the nature of the food that is being eaten. With hard grain or seed, or with berries containing seeds, it is badly needed, and must be obtained if the food is to be digested. Oats and oat husks are all efficiently dealt with by the quartz grit normally found in a Grouse's gizzard, but large hard seeds are not, and are passed undigested. These seeds, however, are sufficient in themselves to pulp fruits so long as fruits only are being eaten. But as soon as heather or other fibrous vegetable matter is eaten, quartz or other stone grit becomes essential. The possibility has been suggested that the replacement of quartz grits by hard seeds of fruit, and the passage of the former through the intestine may act as a vermifuge. So often has a diet of berries apparently Berry seeds n < TT i i i i i as a vermi- arrested a case of Helmmthiasis that it is a question to be seriously considered whether enough attention is given to the encouragement of berry-bearing plants upon a moor. In many cases the sheep keep them so closely cropped that except where there are woods or enclosures it is difficult to find a visible trace of them. It would perhaps repay the trouble GRIT 99 and expense to fence off enclosures from the sheep where any tendency is seen for the growth of Blaeberries, Cranberries, Crowberries, or the like, and the Grouse would quickly find and make use of them. No. 1215 may be cited here as a case in point, for the bird was an obviously convalescent hen Grouse of 16 ounces, with every sign of excessive Helminthiasis, but a complete absence of Davainea, and only one or two portions of Hymenolepis. Trichostrongylus alone was present in great numbers. The gizzard contained no quartz, but was full of hard seeds (cluster- berry or Vaccinium Vitis-idcea). The small intestine, full of food, was very irregularly contracted, and contained not only many unbroken clusterberry seeds, but quartz grits as well, while the rectum contained the same, and exhibited a considerable amount of punctiform, villous reddening, especially in the lower third. Grouse No. 1228 was a rather similar case, the gizzard being crammed with hawthorn seeds, and having no quartz at all, while the small intestine was very much irritated, had its vessels all fully injected with very fluid contents, and yet no Davainea at all. The rectum was again red with injected villi. This bird was caught sick. It was a case of Strongylosis in a hen of 13 ounces only. In the Blackcock the gizzard with its quartz pebbles can crush hawthorn pips, but the Grouse apparently cannot crush any of the pips or even much smaller berries such as Clusterberry, Blaeberry, or Crowberry. They all pass through intact. Nos. 1265, 1723, 1733, 1735, 1817 are all cases in point. It is particularly unfortunate that during deep snow, when Grouse have great difficulty in replenishing their stock of gizzard grits, they are compelled by hunger to feed upon the very foods which most rapidly evacuate their entire stock of grits. The hips and haws whose large hard seeds, as has been said, quickly replace the quartz in their gizzards, are comparatively useless to them for dealing with heather or Blaeberry shoots, yet the bush and tree fruits are amongst the first emergency rations used in a heavy fall of snow, since they come within reach as the ground foods become more deeply buried. The strongest evidence that quartz is the most suitable form of grit is its universal presence in all the vegetable feeding birds that can obtain it. Red Grouse, Ptarmigan, Blackgame, and Capercailzie, as well as Pheasants and Partridges bred on the moor borders, and Scandinavian Willow Grouse, all collect quartz, and nothing but quartz, if it is by any means to be obtained. CHAPTER V PHYSIOLOGY AND ANATOMY OF THE RED GROUSE By Edward A. Wilson As a preliminary to the proper understanding of the method of infection in the Object of forms of " Grouse Disease " known respectively as Strongylosis and chapter. Coccidiosis certain facts concerning the functional activities of the different parts of the Grouse's alimentary canal should be explained. By the alimentary canal is meant the whole tract of the digestive apparatus from the mouth, to the anus or vent ; and the following is briefly a canal de- history of the experiences undergone by a morsel of food after it has been swallowed by a healthy bird. In the case of the Grouse it is reasonable to Lake a small sprig of heather, Calluna vulgaris, with a somewhat woody stalk and a number of very small Character greenish or brownish green leaves, and perhaps a few small pink elt^n'by flowers or shrivelled flower heads containing a considerable number Grouse. o f verv sma ll seeds. Other foods of course are frequently eaten, but all the vegetable stuffs may be considered as partly composed of soft, alterable, and digestible material, such as starch, protoplasm, chlorophyll, and sap solu- tions, and partly of indigestible woody fibres. The animal foods, whether they consist of insect or mollusc, worm, crustacean or spider, can also be considered as composed partly of soft, digestible material, and partly of indigestible matter,, such as chitin. And further, the function of the grit must be considered, since it is as essential to the well-being of a herbivorous or graminivorous bird as a,re teeth Grit. ii.i to the higher mammals. The sprig of heather is partly plucked, partly cut from the growing plant by the beak of the bird. In captivity it is found necessary to fix the bunches of heather either by tying them to the wire run or by placing a heavy weight upon 100 PLATE XXVI. hi Wiis . Opposite p. 101.] PHYSIOLOGY AND ANATOMY OF RED GROUSE 101 the roots ; should this precaution be neglected the bird, having no notion What- ever of using its feet to steady anything, drags the loose heather all over the ground in unsuccessful efforts to pluck off the tips. There is sometimes to be seen quite a free flow of watery saliva from the beak of a feeding bird, and in the mouth of birds killed there is always a certain amount of saliva. This saliva serves to coat the rough hairy heather ' Saliva. tip with mucus, and thus to facilitate its passage down the oesophagus to the crop (Pis. xxvu.a, XLIV.). The food is, of course, swallowed whole but in very small pieces, and there is no mastication. The length of the oesophagus (Pis. xxvi. 03., xxvn., Fig. 1 (a), XLIV.) from the pharynx to the proventriculus is 5 inches ( = 140 mm.), when the neck is normally outstretched; ^ but before passing down the whole length of this tube the food finds s us - its way into a thin-walled sac or diverticulum of the oasophagus, at a point 3 inches, or 75 mm., from its entrance at the pharynx, and commonly called the "crop" (Pis. xxvu.a, XLIV.). Here the food collects, and remains for a longer or a shorter period according to the rate at which the gizzard can dispose of it. The latter portion of the oesophagus measures 2 inches ( = 50 mm.), in length, and the opening of the crop occupies about 17 mm. of the front wall of the oesophagus. The proventriculus p roven . (Pis. xxvi. Pr., xxvn. , Fig. 1 (b), XLIV.) forming the thick- walled trlculus - glandular part of the stomach has a cavity of very small dimensions, and a length of f inch ( = 20 mm.). It is lined with large mucous glands having prominent mouths. These secrete a thick, tenacious, opaque white fluid, where- with the morsels of food on their passage from the crop to the gizzard are coated. In this respect there is a very great difference between the condition of the food as it leaves the crop, and its condition in the actual gizzard. In the crop the food is almost invariably dry, almost exactly as it is plucked from the living plant, and it is found thus in masses fresh and green, or greenish brown, with no appreciable admixture either of mucus or of water. This almost universal dryness of the heather, or other Grouse food, as it is found in the crop, militates strongly against the idea which is occasionally suggested that the Grouse is a thirsty bird by nature, and must have an abundant supply of water. This is almost certainly drj% not the case, for the very rare instances in which the contents of the crop 102 THE GROUSE IN HEALTH AND IN DISEASE were found distinctly wet, were, without exception, in birds showing definite signs of sickness, and in sickness there is no doubt that the bird habits of seeks water and often drinks it. It is, however, very possible that Grouse. . 11 -i i i -i-i water is swallowed straight into the proventnculus, passing by without entering the opening into the crop. If this be so, too much stress must not be laid on the dryness of the food in the crop, in considering the drinking habits of the bird. But with food in the crop, and there is no hour in the day when the crop may not contain some food, all the evidence afforded by an examination of many hundreds of crop-contents goes to prove that water is not freely taken, or if taken, is not admitted to the crop. Probably, when there is food in the crop, no water is drunk, for there is no general condition of wetness at any time either in the crop or in the proventriculus, or in the gizzard, all of which are occupied in turn by the gradual passage downwards of the morsels of food collected in the crop. In the proventriculus, as has been, said, the bits of food, coated now with a tenacious and slightly acid mucus, are passed into the muscular gizzard (Pis. xxvi. (G.), xxvii., Fig. 1 (c), xxvn.a, XLIV.), a familiar object in the anatomy of the common fowl, and an organ of very similar shape and of equal muscularity in the Grouse. Its walls are very thick, and the muscles which compose them act from tendinous sheets, into which they are firmly fixed. The cavity of the gizzard is comparatively small, and is lined with a very tough resistant lining membrane of fibrous tissue, and contains about a teaspoonful of small hard subaugular or rounded grains of hard rock. The substance almost universally chosen by the Red Grouse is quartz, and although on the moor, as in captivity, the bird will swallow any small portion of hard material which comes in its way, quartz is most suitable, not only for the Grouse but for every other graminivorous bird in health. A very extensive collection of Grouse's gizzard grits has been made by the Committee, and carefully examined, and the result most shows the variety of material of which a Grouse will make use when common. quartz is not locally abundant. 1 But the point conclusively proved is that quartz, both on account of its hardness and its method of fracture, is the gizzard grit most abundantly used by Grouse. The subject of gizzard grit is more fully dealt with in chapter iv. 1 Vide chap. iv. p. 95. PLATE XXVII. Fig. I. (a.)- If)-- (i) Fig. 3. (b) "..Cambridge. Opposite p. 102.] PLATE XXVIIA. Trachea Carotid Brachial Aorta Left Auricle Right Auricle Right lobe of Liver Left do. Apex of Gall Bladder Gizzard Pancreas - Caeca Caeca E Wilson. del. et, ath. Cambridge Ofiposilep. 103.] PHYSIOLOGY AND ANATOMY OF RED GROUSE 103 Lead pellets are often picked up by the bird amongst other objects, and swallowed because they are hard and small ; but the suggestion JLjQACt that lead poisoning has ever resulted either in this or in any other pellets in gizzard. way from the scattering of leaden shot over a moor must not be taken too seriously. The food then having reached the gizzard with a free admixture of slightly acid mucus, is now thoroughly mixed up with the grits of quartz, and ground with their assistance to a pulp, the harder woody fibres soon showing Action of up as whitish bits in a brownish, greenish, or reddish mess. This g' zzard - vegetable pottage has now to be separated from the quartz grits, and to be passed little by little into the duodenum. The separation is effected at the distal sphincter muscle of the gizzard, and it often appears as though the sphincter was unable to distinguish readily between the feel of a quartz grit and the feel of a hard seed, or the woody ' Separation "stone" of a berry. It is by no means rare to find, when a bird has of food from grits. been feeding for a time on berries or wild fruits, that the gizzard loses all its rock grits, and contains nothing harder than seeds, pips, or woody " stones." Concurrently with this, it is sometimes found in birds which, from their condition, one would have expected to have contained tape- worms in abundance, that the intestines below are entirely clear of these parasites. We are thus tempted to think that the passage of a Effect of number of quartz grits and hard seeds may have so stimulated the ^f^, ss ' peristaltic action of the intestine, and at the same time have so mtestme - damaged the tapeworms that the latter have been broken off at the neck and discharged en masse. The worms may grow again from the attached head or scolex, but it is possible that even the scolex may in many cases be dislodged, and for that reason the advisability of encouraging such Grouse foods as have big seeds and hard berries has sometimes been advocated. Be this, however, as it may, the digestible food, including our particle of heather, now sufficiently pulped in the gizzard, is separated as it leaves the gizzard from most of the harder and larger grits, and enters the duodenal loop of the small intestine. The duodenum (Pis. xxvi. (D.), XXVIL, Fig. 1 (d), xxvu.a, 1-2, XLIV., 6f inches ( = 170 mm.) in length, begins at the exit of the gizzard and is U-shaped. It consists of two parallel " limbs " of about equal length. These two limbs are supported and held together by a mesentery 104 THE GROUSE IN HEALTH AND IN DISEASE which contains the pancreas (Pis. xxvi. Pa., xxvu., Fig. 1 (e), xxvu.a, xxviu., Fig. 1 (e), XLIV.), a pale pink, flattened glandular mass filling the space between the descending and ascending limbs. This gland pours its alkaline and digestive pancreatic juice and ferment into the upper end of the descending loop. The liver (Pis. xxvi. (L.), xxvu., Fig. 1 (/), xxvn.a), also pours its alkaline, biliary secretion into the upper end of the descending loop, so that it is intimately mixed with the pulped food as it passes into the duodenum little bv Liver. little. The shape of the loop assists this admixture, since it checks the immediate passage of the contents into the convolutions of the upper small intestine. Digestion is now ready to go on apace. The food, when being macerated and pulped in the gizzard, is distinctly acid ; but, when mixed with the alka- line pancreatic and hepatic secretions from the liver, becomes gradually Chemical J action of neutralised until it is of the right reaction as well as at the right temperature for the action of the digestive ferments. 1 In the duodenum the contents are normally almost fluid, when there are no tapeworms or threadworms present. The duodenum is, however, the common habitat of Hymenolepis microps, and of Trichosoma Parasites . . . found in longicollis ; and the former of these is frequently present in such duodenum. . large numbers as to appear like a soft, semi-solid, creamy mass completely filling the whole length of the duodenum (PI. xxviu., Fig. 2). It is only when this worm is absent, as it generally is during the winter months, that one appreciates the fact that the duodenum seldom contains at any one particular moment more than a very small amount of solid food pulp mixed with the digestive fluids. The passage of the food through it is very gradual, and the admixture with the alkaline digestive juices is proportionately complete. Normally the outward appearance of this part of the intestine is a pale creamy white, and the mesenteric vessels which ramify over the peritoneal surface are almost invisible. The pancreas also should be pale creamy white or faintly pink (PI. xxvm., Fig. 1 (a) (e) ). The alkaline mixture now passes from the duodenum into the convoluted upper portion of the small intestine (Pis. xxvi. (c.s.i. ), xxvu., xxvn.a, XLIV., Small Fig. 1 (g)). This extends from the lower end of the duodenum to intestine. tfle U pp er en( J Q f ^ e rec tum (Pis. XXVI. (R.), XXVII., Fig. 1 (/i) XLIV.), 1 Vide pp. 105, 106. PLATE XXVIII. E.Wilson, Cambridge. Opposite p. 104.] PHYSIOLOGY AND ANATOMY OF RED GROUSE 105 where the two caeca enter it. The small intestine measures in all 35 inches ( = 872 mm.); but there is a distinction to be made between the upper or proximal convoluted portion which is attached to a wider mesentery, and the lower or distal straighter portion (PI. xxvi. s.S.l.) which is attached to a much narrower mesentery. And, while there* is probably a difference in the character of the glands which form the mucosa of these two portions, the chief obvious distinction is that the convoluted portion is freely moveable, whereas the straight portion is so intimately folded with the long csecal appendices, and so closely bound together with them in a common mesentery as to be very limited in its movement. The various parts of the lower intestine are shown laid out in the accompanying diagram (PI. xxvi.), while the next diagrams shows them as they appear in their normal condition in the body cavity of the bird (PL xxvu., Fig. 1, xxvu.a). Returning, however, to the changes which are being experienced by the particle of food in question as it passes from the duodenum into the convoluted portion of the main gut, it is first noticed that the accompanying duodenal tapeworm, Hymenolepis microps, wholly disappears, and that its place is taken by the much larger and more conspicuous tapeworm, Davainea L arge urogalli, often in such quantity that the outward appearance of the ta P eworn] - small intestine is altered to a swollen, bulky gut of a creamy white colour due to the enclosed mass of tapeworms shining through the thin and distended walls. Another point has already been noticed, namely, that the neutral or faintly acid reaction of the contents of the duodenum now gradually changes to a more and more markedly alkaline reaction. Hymenolepis affects a neutral medium, and Davainea an alkaline medium. These changes in the character of the intestinal contents can, of course, be easily tested by the use of litmus papers ; but when a Grouse, which has been feeding upon ripe Blaeberries, Cranberries, or Crowberries with coloured juices, is examined, the contents of the alimentary canal of the bird itself are found to be coloured within from end to end, in such a way as to make litmus unnecessary. The juices of the berries are red, and stain the tissues red wherever the acidity is not overcome by alkaline digestive juices. But wherever there is a slight alkalinity in the juices there the tissues are stained bluish. This is shown in the accompanying figures, which are drawn directly from the dissection of a berry- feeding Grouse (see PI. xxvir., Figs. 2, 3, and 4). 106 THE GROUSE IN HEALTH AND IN DISEASE Fig. 2 shows the food contents to be blue while in the proventriculus (alkaline), on reaching the gizzard (acid) they change to reddish purple, in the duodenum (slightly acid to neutral) they lose much of the red tint, but it is not until they enter the small intestine (alkaline) that they again resume the blue colour (see Fig. 3, representing one of the coiled loops of the small intestine), the alkaline reaction continues throughout the length of the small intestine as far as the lower end of the rectum (Fig. 4 (h)), where it becomes slightly more acid, and the acid reaction of the cseca (Fig. 4 (i)) also causes the colour to change to a reddish tone. In the convoluted intestine the food is in a somewhat fluid state ; and as the mere presence of convolutions in the intestine of any animal are evidence of the necessity for a retarded passage, the function of the convolutions Reason for convolu- in this case is obviously to hold the mixture for a sufficient length of tions. . . ' time at a certain regular temperature in order to give the active digestive ferments every chance of completing their work upon the food-pulp. The heather-pulp is thus altered, so far as its alterable part is concerned, into a solution of assimilable food and an indigestible refuse of woody fibre. The raw material here becomes the digested material ready for use by the tissues of the body as soon as it can be brought to them by the agency of the circulating lymph and blood. Certain harmful and poisonous products will also unavoidably Elimina- appear in the Grouse's intestine as they do in the human intestine and poisonous * n tne intestine of every living animal from time to time, even in the ordinary course of digestion. These, as in the human body, having been absorbed with the soluble food supply into the blood are then eliminated, chiefly in their passage through the liver, before the mixture of good and evil products can be thrown upon the general circulation. The liver in man is the great eliminator of poisons produced in the intestine, and the liver in the Grouse almost certainly acts in a similar way. There is probably some selection and some chemical alteration during the passage of the food, including that part of our heather fragment which has now been digested, through the mucous membrane into the blood-vessels. By the time the food reaches the lower and straighter portion of the small intestine it is seen that much of the fluid has disappeared, the contents are becoming more and more thickened, and are now converted into a semi-fluid paste interspersed with woody particles. By the time that the contents reach the junction of the small intestine with the rectum they have been still further PHYSIOLOGY AND ANATOMY OF RED GROUSE 107 prepared for separation. At this point the cascal appendices (Pis. xxvi. cl, c2, xxviii., Fig. 3 (i), XLIV.) open into the main gut, and all that is . . , . Cseea. soft is now squeezed into the narrow openings of the csecal appendices ; while all that is hard, including the indigestible part of the heather fragment, the indigestible woody fibres, and the refuse of the cellular tissues, is compressed into a firm, dry mass, and so passed straight into and along the rectum. Each csecal appendix measures from 30 to 36 inches (762 to 915 mm.) in length. Their colour in health is a dull drab grey, while that of the small intestine is greenish ; the difference in colour between portions of the alimentary canal are shown on PI. XXVIL, Fig. 1, representing the normal duodenum (d), pancreas (e), small intestine (g), caecum (i). When excrement leaves the body of a normal healthy Grouse it does so in two distinct forms. The firmer excrement described above passing through the rectum leaves the body first, and either immediately, or after a Two forms short interval, the more fluid and pasty unabsorbed contents of the csecal appendices follow without having mixed at all with the dejecta of the main gut. The dry and often quite hard Grouse " dropping," which outlasts much weathering, can be seen on many moors without any particular search, some- times at every yard or two upon bare burned ground, where it becomes bleached almost white under the combined action of sun and wind before it is broken up to be disseminated as dust. The matter is one of some importance, for the perfectly normal csecal dejecta of the Grouse are so often considered abnormal, and even pathological, by game- keepers and by sportsmen, and are so constantly credited with having some mystic relation to " Grouse Disease " that it becomes necessary to explain the appearances in detail. In walking over a well-stocked moor, in fairly dry weather, Grouse's droppings are to be seen lying in small heaps upon the ground where birds have "jugged" or roosted amongst the heather at night. It is sometimes surprising to see how many of these compacted rolls of undigested woody fibre are passed by a single bird in one night. Each hour throughout the roost there appears to be a separate motion, and always of the hard " formed " dropping coming directly from the main gut, and not of the pultaceous, soft, csecal matter. But, when morning comes, and especially when the bird has moved to the neighbourhood of water for the 108 THE GROUSE IN HEALTH AND IN DISEASE purpose of drinking, the caeca discharge themselves, and the typical soft caeca! dropping, which is so frequently misinterpreted as a sign of sickness, is then deposited either upon the harder dropping of the night if the bird has not already moved away, or more usually somewhere in the near neighbourhood. During the night the main gut and the caeca appear to be engaged in a divided labour. While each caecal appendix is employed in the absorption of nutritious, fluid solutions from the soft mass of food within it, the lower part of the small intestine is continually receiving from above more and more of the mixture of soft digested pulp and hard indigestible waste matter. The exact method of separation is due to the action of the sphincter muscles Method of which regulate the opening and closing, not only of the two entrances separation. j. Q ^3 caecal appendices, but also of the entrance to the upper end of the rectum. There are no actual valves and no visible folds, but each caecum at its junction with the main gut is guarded by a narrow tubular portion (Pis. xxvi. cl, c2, xxvil., Fig. 4 (i), xxvni., Fig. 3 (i)) some 4 or 5 inches (102 or 127 mm.) in length, which is lined by a mucosa rich in small projecting papillae, and which admits nothing to the caecum except the softer parts of the pulpy mixture. The pultaceous, creamy-brown pulp must be thus squeezed into these caecal back-waters by the peristaltic pressure of the small intestine from above, while the rectum at the same moment refuses to admit anything at all. Each caecum has one blind end and one end opening into the upper part of the rectum. All the useful contents of the main gut must pass into the caecum, and the undigested portion must pass out again by the same orifice. Yet the caeca always appear to be filled to some extent by material from one end to the other. It is only after a prolonged starvation, say for twenty-four hours or more on a railway journey, that the caecum is found in the condition represented Manner in PI. xxviii., Fig. 3 (i), and it is obvious from this figure that the cascaare 1 riddance begins by contraction of the blind end, and that it gradually emptied. wor k s toward the open end. It would appear from this that there must be a pause in the entrance of material to the caeca while they are evacuating the waste matter. The musculature of the small intestine seems thus to act intermittently but frequently, and without any long period of rest. The caecal musculature, on the other hand, must have long periods of rest when the caecum is full or actively absorbing, and then a period of activity to empty itself. But these periods of rest and activity must be of very different length. It is con- PHYSIOLOGY AND ANATOMY OF RED GROUSE 109 ceivable that after full feeding in the evening the Grouse jugs in the heather, and the process of digestion and the action of the intestine proceed until there is a large quantity of hard and soft food in the lower part of the small intestine ready for selective absorption and separation. This separation probably proceeds all night, the soft material constantly passing into the caeca, and the harder waste matter passing on as constantly into the rectum and out at the vent. Then, early in the morning the action is reversed, the passage of food down the main gut ceases because the supply from above has been stopped during the night when, of course, nothing has been eaten. The useful part of the csecal contents has now been absorbed, and is circulating in the blood, and the caecum therefore contracts downward and expels all the waste matter that is in it. This is borne out by what one sees upon the moor, by the absence of caecal excreta amongst the heap of formed droppings passed in the night, and by the occasional appearance of some caecal excreta on the top of these heaps, though more frequently in their near neighbourhood or near the early morning drink- ing and feeding resorts. There is, moreover, now no doubt that the Grouse feeds more or less all day ; but, as a rule, the crop is found fullest times of . Grouse. in the evening. Probably digestion is sufficiently rapid during the day to deal with the food almost as fast as it is picked and swallowed. It may be that the caecum receives matter both by day and by night, and discharges its contents only in the early hours of the morning ; but these details are not easy to determine in the wild bird, though it is easy to see how indispensable it is to the well-being of the Grouse that the caeca, whose combined length nearly equals that of the rest of the alimentary tract, and which are responsible for the absorption of most of its food, should be in good working order. It importance seems impossible to exaggerate their importance in the bird's economy, of 08eca - for if they are put out of action the bird may eat as much as ever and yet rapidly lose flesh by sheer starvation. It may suffer even worse things owing to the decomposition of the food and the diminished powers of selection during Danger of absorption, thus causing toxaemia. That this happens is evident, for tox8enua - it is a very usual occurrence to find the caeca in a case of Strongylosis, com- pletely filled by a semi-dried mass of foul, caecal matter adhering to the mucosa, leaving very little room down the centre for the passage of anything at all. In such cases the Trichostrongylus is usually excessively abundant, and may Tricho- be seen bridging the space by hundreds between the adherent faecal mass and the mucosa from which the latter is being forcibly separated in dissection. 110 THE GROUSE IN HEALTH AND IN DISEASE One portion of the alimentary canal remains to be mentioned, namely, the rectum (Pis. xxvi. (R.), xxvu., Fig. 1 (h), XLIV.) This measures but 4|- to 5 inches ( = 115 to 127 mm.) from the point of entrance of the Rectum. caecal appendices to the anus. The internal appearance of the normal healthy rectum is shown on PI. xxix., Fig. 2 ; in this figure the dark staining about the caecal orifice is due to the proximity of the liver. The rectum appears to evacuate its contents almost immediately after receiving anything from the main gut or the cseca. When examined by dissection it is generally empty, or at the most but sparingly occupied by material ; but there is one marked exception to this statement. In the hen Grouse, during the laying of eggs and incubation, but especially during incubation, the want of exercise, and the necessity for keeping the nest clean, leads to an excessive accumulation of faeces, always of the harder, formed kind, in the lower part of the rectum. There is a great increase of size and of development in the ovary and oviduct in the breeding hen Grouse, and the rectum appears to accommodate itself to this. The massed and bulky droppings of a sitting hen Grouse, or "clocker" as she is called, are well known to the gamekeeper as affording the most reliable and useful information he can have concerning the number of nests upon his moor. These droppings, due to want of exercise and the brooding instinct, result in an enlargement and distention of the lower part of the rectum and the cloaca, which recover themselves only after incubation and hatching are completed. As these bulky "docker's" droppings are only to be seen on the moor in the nesting season, it is perhaps not surprising that the keeper alone recognises what they mean. It is a very common thing for a keeper to congratulate himself upon their abundance along the side of every burn he comes to. Such places are used habitually by sitting hens when they leave their nests, perhaps once or twice a day, for food and water, and these droppings supply far more satisfactory evidence than could be gained by disturbing the birds on their nests. This then is, as briefly as possibly, the normal course of the digestion and Variations absorption of food in the alimentary tract of the Red Grouse, and digestive it remains now to speak of the more common pathological variations and disturbances which affect this process and which upset the health of the bird. PHYSIOLOGY AND ANATOMY OF RED GROUSE 111 Many such variations have come to light during the past five years in the course of dissecting something like a couple of thousand Grouse : of these some were healthy and some unhealthy ; but in this chapter no account is given of lesions resulting from shot wounds or collision with wire fences or similar accidents. This subject is dealt with in another chapter. 1 By far the more important pathological changes which are to be found in the Red Grouse are those which result from excessive parasitism, and they are therefore discoverable as a rule in the intestines, and above all in the two blind csecal appendices, which afford a habitat to thousands of the round - worm Trichostrongylus pergracilis. The particular csecal lesion, connected with this threadworm, and with the fatal Grouse disorder which is now called Strongylosis, will be dealt with separately. 2 It will best serve the purpose in view to take again the alimentary tract from end to end, and to mention the lesions to which the various parts are liable. 3 It is a very rare thing to find any disturbance in the upper reaches of the alimentary canal. The mouth, the oesophagus, the crop, the proventriculus, and the gizzard as a rule carry no entozoa, and are very seldom the seat of any pathological trouble. But it may happen that a bird gets hold of some irritant poison with its food, and this probably accounts for one or two other- wise unaccountable cases of inflammation of the crop walls, with engorgement and enlargement of all the vessels ramifying over it, and desquamation of the lining membrane (e.g., Nos. 1611 and 1759). In one bird (No. 1703) the crop contained plenty of fresh green Calluna tops, with Blaeberry leaves and bits of Potentilla, mixed up with abundant legs of the crane fly, all perfectly normal and wholesome foods, but the wall of the crop was excessively inflamed, the lining tfonof mi membrane shed, and a roughened surface was left exposed ; there was ' rop ' much fluid mucus, and all the vessels were injected and engorged. There was also thickening of a granular appearance in the lower third of the oesophagus ; but the mouth, throat, and trachea were all healthy. The mesenteric vessels were engorged and varicose, and the bird, which was a cock, and a bad case of Strongylosis, was infested with both kinds of tapeworm, weighed 15 ounces only, and was found dead. 1 Vide chap. ix. p. 153 et seq. - Vide chap. x. p. 207. ' J Vide Diagram, p. 290. 112 THE GKOUSE IN HEALTH AND IN DISEASE Again, No. 1846 was a hen Grouse of 15 ounces only, found dead on May 6th, 1909, in Perthshire. This bird was very backward both in moult and in the development of the ovary. There was no attempt to put on the nesttna, 1 plumage. But the cause of death was an excessive Congestion . ? of food in repletion of the lower oesophagus and proventriculus. From the level oesophagus. of the base of the heart to the point of admission to the gizzard the mass of food in the oasophagus and proventriculus formed a uniform sausage- shaped mass, which seems to have caused death by pressure upon the heart within the thorax. Why this collection of food should have failed to find its way into the gizzard it is impossible to say. Mechanical obstruction there was none, either by unusual food or by stricture. These were at once looked for without success. Some spasmodic stricture of the entrant sphincter muscle of the gizzard may have accounted for this, though there was no direct evidence of it. The gizzard and its contents were perfectly normal, and there was apparently free passage both in and out of it. The crop contents were unusually moist with water and watery mucus. They consisted only of green Calluna heather-tops, but there was a much smaller quantity in the crop than in the proventriculus. There was no appearance of damage by shot or other means, such as might account for paralysis of the lower oesophagus, though this would, perhaps, be a plausible explanation, as the damage done to a nerve in the neck by a stray pellet could have been healed without leaving any noticeable scar, and yet the nerve remain severed, thus putting out of action the parts it supplied. No. 1311, a hen Grouse of 16 ounces found dead on March 30th, 1908, in Perthshire, was a case presenting almost exactly the same appearances as the above, and with no clearer evidence of its cause. This bird was very thin, and was found not far from a dead grey-hen ; but the grey-hen showed no sign of similar trouble. In this Grouse the crop contained a small amount of large pieces of woody Calluna heather. The proventriculus was perhaps a little swollen, but the lower half of the oesophagus was intensely engorged with food, making again a sausage-shaped swelling within the thorax, which must have exerted a fatal pressure upon the heart and blood-vessels. The bird was not suffering from Strongylosis to any noticeable extent, that is, the caecal villi were not engorged. It is a possible solution that the crop having received something irritat- ing in the food, acted suddenly and completely, emptying itself into the Cause may be thread- worms or tape- worms, PHYSIOLOGY AND ANATOMY OF EED GROUSE 113 oesophagus, and thus paralysing this part of the alimentary tract by over-distension. The contents were not examined for irritant poison, but the birds might possibly obtain some such poison if they fed off heather which had been contaminated by sheep dip in dry weather. This, however, is not probable in March. In the duodenum it is comparatively common to- find the mucosa intensely engorged, showing a bright red surface to the naked eye, sometimes all over, and at other times in patches. This is apparently the result some- times of the presence of Hymenolepis microps, in large numbers ; ment in sometimes of the presence of Trichosoma longicolle. Such a mucosa, seen under the lower powers of the microscope, shows that the vessels of the villi are all full of blood as shown in the accompanying figures (see PI. xxviil., Figs. 4 and 4 (a)); but although in many cases the mucosa is thus reddened and Hymenolepis and Trichosoma are abundant, it is be thread- won" * also quite as frequently found that the worms are present without tape any reddening, and in some cases reddening is present without any sign of a worm. Nevertheless one very common association in the duodenum, whether it has anything to do with cause and effect or not, is that in one and the same bird Hymenolepis occurs in very large numbers, the villi are densely injected, and the fluid bathing the worms has the appearance of being bloody (see PI. XXVIIL, Fig. 2). For example, in No. 1200, weighing 21^- ounces, found sick, the duodenum was of a deep red both inside and out, the villi all injected, the mesenteric vessels all engorged, and Hymenolepis was present. The bird had, however, Or corn been feeding on corn, and it is possible either that the siliceous feedm g- spicules of the oats were the cause of much irritation, or that the general venous engorgement resulted from the Strongylosis which was also present. It is also probable that in many of these cases where there is villous engorgement and redness of the mucosa in the duodenum and smaller intestine, Coccidia have been the cause and have been overlooked, and that Or the more obvious threadworms (Trichosoma) have really little or Coccldia - nothing to do with the engorgement. It may exonerate Hymenolepis and Davainea to some extent, that both may be present in masses without any accompanying congestion, but the occurrence of a large number of Trichosoma longicolle in the duodenum, associated with an accompanying congestion of the mucosa, and the presence in the gut of dark bloody - looking fluid is too frequent to allow this VOL. i. H 114 THE GROUSE IN HEALTH AND IN DISEASE nematode to escape blameless in the company of the two above - mentioned cestodes. Trichosoma is probably a harmful worm, but as it seldom occurs, as compared with the frequency of Trichostrongylus in the caecum, the damage done by it is comparatively trifling. In the duodenum then it is possible to have Hymenolepis present in large numbers with or without engorgement of the villi, but when, as in No. 1525, Hymenolepis occupies no less than 8 inches of intestine, extending from the duodenum for several inches into the small intestine, the villi may be exces- sively congested. In such a case, moreover, as in No. 1864, if the bird has Strongylosis the congestion of the ruesenteric vessels seems to affect the appearance of the duodenum also. Normally the duodenum and * ne P ancreas are P a le creamy pink or white with no visible external blood-vessels ; but this is altered under conditions producing con- duode- gestion, to a deep red or bright purple or crimson colour over which the engorged vessels ramify (see PI. xxvni., Fig. 2). As already stated, the villi of the duodenum may be occasionally found in a state of excessive redness, with apparently no trace of a worm of any kind. Such a case was No. 1391, but it was also a very bad case of Strongylosis in a hen found dead, so the change may have been post-mortem only, or it may have formed part of a more general congestion. Typically the duodenum when badly infested by Hymenolepis looks bulky and translucent, swollen and soft and is of a pinkish yellow colour, with thin walls. The upper end of the ascending limb is often deeply stained by contact with the liver. The contents besides the Hymenolepis are fat globules, no crystals, as a rule, but an abundance of shed, endothelial cells. The fluid con- tents, always small in amount, of the duodenum are generally yellowish, and may be blood-stained if Hymenolepis and Trichosoma are present in excessive numbers. It is not a rare thing to find that in a sick bird the control of the lower sphincter of the gizzard is lost at the point of death or somewhat earlier, and that the grits have passed out of the organ in large quantities into the duodenum. Normally the grits are retained in the gizzard for a considerable time, certainly for months, if they are of any size. Much depends upon the nature of the food, and as already explained the presence of hard, woody seeds may lead to the loss of most of the gizzard grits, in which case they are passed with the dejecta. 1 1 Vide p. 97. PLATE XXIX. Rectum Villi of Fig. 5 magnified L jindtr-5 jndi obj. Fig. 6. Keotum Posterioi third very much inflamed Typical appearance of small Intestine when filled with D. calva. Fig Rectum, inflamed condition. Rectum, punctiform infection of villi. Fig. 2. Rectum normal or nearly so ; the dark staining about the cfecal orifice is due to the proximity of the liver. E.Wilson, Cambridge Csecum cut open longitudinally Opposite p. 115.] PHYSIOLOGY AND ANATOMY OF KED GROUSE 115 Passing now to a consideration of the small intestine, and its pathological manifestations, the first noticeable point is its external appearance when really full of Davainea calva, as is so frequently the case (see Plate Small in . XXIX., Fig. 1); the gut is distended, and appears fatty, thin- testine - skinned, yellow in colour, and rather translucent. Within, there are often great masses of Davainea, but no redness of the mucous membrane. In No. 1219, a cock Grouse of 21 ounces, found dead, the whole of the lower straight portion of the small intestine was enormously distended with food not long eaten. The crop contained Calluna tops, a few obstruc- insects and some seed - heads of a Ranunculus. The gizzard con- s ^\i tained plenty of quartz and food ; the duodenum contained Hymeno- mtestme - lepis ; and the upper small intestine a few Davainea. The caeca were almost empty, and although no obstruction was visible there was obviously something preventing the admission of food to the caeca from the lower main gut. The distended intestine measured nearly 2^- inches round, and the thickening of its walls showed that the condition was not merely temporary. The mucous surface was roughened with greyish-white, swollen mucous glands which may have been the cause of the trouble, since they probably failed to supply sufficient moisture to the food for its passage into the caeca. It was a condition analogous to excessive and prolonged constipation, and it is evidently a rare condition in the Grouse, for no other case like it has been seen. A punctiform pigmentation of the serous surface of the small intestine is not uncommon. It occurs in small areas which are thickly dotted with black pigment. Probably it results from a previous inflammatory condition, or small localised peritonitis, which may possibly have tionof surface. been caused by the masses of Davainea within the gut. Grouse No. 1182 and No. 1739 are good examples of this condition. In the latter the pigmentation was more or less generally distributed over the serous covering of the caeca as well as of the small intestine, and as the bird had been wounded by shot some considerable time before it was killed, there is a likelihood of the peritonitis having been more general than local, though there were enough worms and congestion in the intestines to account for the appearance. It is not a common thing to find the small intestine acutely inflamed, or very red or congested, but in Grouse No. 1113 the straight portion was . . Inflamma- excessively red with orange-coloured mucus, evidently blood-stained, tionofin- c testine. and a very large number of Davainea. This, however, was a 116 THE GROUSE IN HEALTH AND IN DISEASE bad case of Helminthiasis, with intussusception ; the caeca also were intensely congested and very much thickened, the lower third especially was blood - red, and full of Trichostrongylus. The duodenum also was much inflamed, and for a male the weight, 15f ounces, was, of course, exceedingly small, showing that it had suffered severely in its struggle with so many parasitic worms. Of this condition, therefore, one might expect well-marked post-mortem evidence. The intussusception was probably the result of great irritation. The only pathological appearance which is commonly seen in the rectum of the Grouse is a reddening along the glandular ridges, due to villous engorge- ment. This appearance is illustrated on PL xxix. where Fig. 2 Inflamma- . tionof shows the rectum in a normal healthy condition. Jig. 3 shows the same when inflamed throughout its length. Fig. 4 shows the rectum with the posterior third very much inflamed. Fig. 5 represents the punctiform injection of the villi, while Fig. 6 shows the same injection when magnified under a 1-inch objective. The cause of this villous engorgement is obscure, but it is much more frequently found about the lower third of this portion of the gut than about the upper two-thirds, though it may be general throughout the rectum. It does not appear to be dependent upon disease or sickness, though apparently sometimes it has some relation with an excessive number of tape- worms in the main gut. In the caeca of the Grouse lies the whole origin and cause of " Grouse Disease" in the adult bird. In these blind guts lives Trichostrongylus pergracilis, and these, when present in enormous numbers, produce an excessive amount of irritation and congestion of the vessels and of the Tricko- capillaries in the villi, desquamation of the endot helium, and so much strongyius. disturbance of the proper functions of this portion of the gut that the contents, consisting of food, mucus, nematode worms, and nematode ova in a pasty and decomposing mess, not only become useless as food, but a grave danger to the bird owing to the amount of toxins produced and absorbed into the circulation. The internal appearance of the normal caecal mucosa is shown on PI. xxx., Fig. 1, which represents a section of the caecum of a healthy bird ; the nodules and granular ridges are yellowish, and the interstices are dark reddish brown. The external appearance of the normal healthy caecum as it lies in the body of the Grouse is seen in PI. xxvu., Fig. 1 (i). But when badly PLATE XXX Fig.3 Fig.5. ' Opposite p. 117.] PHYSIOLOGY AND ANATOMY OF EED GROUSE 117 infested with Trichostrongylus both the external and the internal appearance become quite altered (see PI. xxx., Figs. 2, 3, 4, and Figs. 5, 6, 7, 8, 9). In this Plate, Fig. 2 shows the caecum much swollen with the mucosa thickened and congested, and the mesenteric vessels engorged, the mucosa show a little red, punctiform inflammation from the injected villi, otherwise the colour is grey and the ridges are tumid and much swollen. Figs. 3 and 4 show the caeca much congested, and the meseuteric vessels engorged with dark venous blood. Fig. 5 represents an exceptional appearance, the four greater and four lesser ridges are well defined, there is no trace of nodules, but there is slight inflammation. Fig. 6 shows the interior of the lower end of the caecum, and Fig. 7 shows a section of the middle third, in both these examples the mucous membrane is much congested, and hypertrophied with fully injected red villi. Figs. 8 and 9 show the appearances in a bad case of Strongylosis. Other extreme cases of Strongylosis are shown on PI. xxxi., where Fig. 1 represents a portion of the caecum at the junction of the lower and middle thirds. Fig. 2 shows a similar appearance in the middle third. Fig. 3 illustrates a section of the first third intensely congested, while Fig. 4 shows the same when magnified under a 1-inch objective. In Fig. 5, showing a section between the lower and middle third, there are large spaces with no trace of ridges ; but it is probable that this is the effect of post-mortem change. Instead of an intestine of a brownish or greenish grey colour moderately filled with soft brown pasty material, and showing greyish yellow lines running down its length on the outside, indicating the eight or nine long villous Appear- ridges within, we see in the caecum of a diseased bird a distended tube, unhealthy with overfull and congested blood-vessels ramifying over it on the 08eca - outside, standing out very often in conspicuous contrast with a yellowish fatty- looking gut-wall ; or the whole substance of the wall of the caecum may be congested to a deeper tone, and may look dark, blue - black, and unhealthy. Before opening the gut, however, the congestion of the mesenteric vessels is the most conspicuous point. This is due to a venous congestion, and it means that the liver and other abdominal viscera and the right side of the Li vera nd heart are overfull. The liver may be very dark. It decomposes heart - rapidly, becoming of a black, tarry, soft and very rotten consistency ; but this is not a safe indication of disease. The difference in appearance between a healthy liver during decomposition and a diseased liver is so uncertain that, after a day or two of summer heat, it becomes impossible to judge whether 118 THE GROUSE IN HEALTH AND IN DISEASE the bird was diseased or not. The right side of the heart is often enormously distended with black blood in a bird that has died of disease. This condition of the heart, however, must not be taken as necessarily present when the caecum is diseased. When the caeca of a large number of Grouse, all more or less suffering from Strongylosis, are opened up and examined in various stages of freshness, and in some cases after a lapse of many days since death took place, the appearances are very variable. In some birds the upper portions of the caecum are almost transparent (see PI. xxxi., Fig. 6), but this transparency is certainly increased by the post- mortem maceration of the mucosa. The longitudinal ridges, moreover, gradually diminish in breadth and in villosity as the blind end is approached. The thickenings so conspicuous in some birds are far more abundant at and towards the open end. The ridges are sometimes very obviously alternately large and small, giving four broad and thick and four narrow and thin (see PI. xxx., Fig. 5). In bad cases the villi are intensely congested, and in a certain number of cases there is evidence of haemorrhage having taken place here and there. But extensive haemorrhage does not occur in Strougylosis, or at any rate no indication of extensive haemorrhage has been seen in any bird dissected. The reasons which lead to the belief that there is always a loss of blood as a chronic symptom in this disease are that the congestion is always present, and is often excessive ; that small haemorrhages have been seen, and that in some advanced cases there is every appearance that one would expect to find in anaemia in a bird. It must be allowed that without Dr Fantham's blood examinations this would be an insufficient explanation. In some birds the pale, bloodless, fatty and degenerated aspect of the tissues of the internal organs was most suggestive of anaemia, and of chronic toxaemia. It is possible to find quite a number of very healthy looking birds with good weights and yet with a large number of Trichostrongylus and a considerable Tfieho- amount of villous reddening. This goes without saying in such a iuheaUhy disease as Strongylosis, which is essentially a progressive ailment. Everything depends upon the strength of the bird, and its power of resistance. There is no doubt that some birds will retain their weight and continue for some time in apparently perfect health, with a very great number of Trichostrongylus in the caeca, and a considerable amount of con- PLATE XXXI. Fig 3. Fig Z Fig. 7. Fig 10 Fig 4 Fig. 8. ' T--- i TRANSPARENT ' INTtBT'lNE Fig 6. m Fig 5. Fig 9 .E Wilson, Cambridge Opposite p. 118.] PHYSIOLOGY AND ANATOMY OF RED GROUSE 119 gestion. There is also little doubt that an observer may be easily misled by a physiological redness of the cascal villi due to normal processes of digestion. This is especially the case if the bird examined happens to have been in the middle of this process at the moment of death, and if death occurs without loss of blood. The abdominal viscera must all be more full of blood at that time than at others, though in a bird like the Grouse which eats all day long, the difference may be less marked than it would be in ourselves or in birds of prey which feed at longer intervals. The chief signs of a bad case of Strongylosis so far as the caecum gjg ns of OJ Strongy- is concerned are : losis - (1.) An excessive number of the worms, which can be seen stringing across between the mucosa and the caked contents of the gut, if the contents are fairly dry. If not, then, by taking a small quantity of the pultaceous contents and squeezing this flat between two glass sides, the worms can be easily seen as transparent threads when held up to the light. Innumerable ova will also be found lying free in the caecal contents. (2.) The longitudinal ridges, eight to nine in number, are very much thickened, chiefly because the amount of blood held by them is excessive, and the villi are all engorged. (3.) The swellings shown in PI. xxx. (Fig. 1), and conspicuous in a healthy bird as greyish nodules, are far more conspicuous in a case of Strongylosis when they are reddened and congested, and seem to suffer to a greater extent and earlier than the remainder of the ridges and the rest of the caecum (see Plate xxx., Figs. 6 and 7). In some cases, however, the time comes when every villus in the whole gut seems to be intensely red and congested from one end to the other (see Figs. 8 and 9). (4.) There may be a very great deal of mucous thickening, from the swelling up of the villi and their columnar epithelium cells, and after maceration post- mortem, the cascal mucosa seen in water may have the appearance of a furry rug. The mucous contents of such caeca are sometimes obviously blood - stained, and there is probably a haemorrhagic form of the disease which results from the sudden access to the gut of a very great number of larval worms all in a fully metamorphosed state. Such a case was produced experimentally at Frimley, and haemorrhages occurred in the caeca. There is no apparent reason why under certain easily imagined circumstances the same thing might not happen in early springtime under natural conditions. 120 THE GROUSE IN HEALTH AND IN DISEASE (5.) There may be appearances of recovery. In a good many birds the caecal mucosa is dotted all over with minute black pigment granules, in other words some of the villi show no blood-vessels injected, but are filled with pigment granules instead. These are sometimes so abundant as to colour the gut. They lie in the villi in great numbers (see Plate xxxr., Figs. 7 and 8). It is possible that they result from previous chronic congestion and that there are circumstances under which the bird may rid itself of an excessive number of Trichostronqylus. If there is any plant Possibility ' of recovery which acts as a vermifuge to this nematode on the Grouse moor, from strongy- and if it could be discovered and encouraged to grow one cannot help thinking that the Grouse might learn to eat it. If this supposed recovery from Strongylosis has not resulted from some unknown vermifuge herb, then it must have resulted from improved conditions of life ; and the one condition of life which is in the hands of the moor pro- prietor is the food supply. It thus becomes imperative to give every Grouse on the moor the best possible chance of overcoming the parasitic pest which produces what is probably the most harmful feature of the disease, namely the chronic congestion of the villi of the cseca. Improve the conditions of life, improve the circulation so that the heart and lungs work more efficiently, and the digestion automatically improves, as also does the elimination of toxins, whether produced by the parasitic worms, or by the food eaten, or by bacteria in the gut. The worms, one must suppose, remain in the gut ; but the congestion is overcome, and the bird is not very much the worse for their presence. But, if the congestion is allowed to continue and become chronic, the digestion and absorption of food must go from bad to worse, and with it every other function of the body. Nothing will prevent the bird in this case from losing its weight, and eventually its life. As for the exact cause of the congestion, it may be due to mechanical constriction of the filamentous processes of the villi by the nematode worms. The im- Each time the gut acts peristaltically the worms have to hold on causfTof tightly to the mucosa or else be dislodged with the dejecta, and congestion. fa Q result is seen in sections where the villi are evidently mixed up inextricably with the coils of Trichostrongylus. Or it may be due to the chemical irritation of some poison produced in the gut by the worms, or by the defective digestion of food stuffs, or by bacteria living in the gut in its unwhole- some state. Or it may be due to some or all of these conditions together. PHYSIOLOGY AND ANATOMY OF RED GROUSE 121 On the whole the mechanical view seems the most probable. The peristalsis is acting in a way to dislodge the worm, and the Trichostrongylus has no other way of retaining its position in the cseca save by coiling round something, and the peristaltic action of the caecum must be fairly strong in comparison with the strength of the worm, for the free end of the worm has to be released at every wave of peristalsis from immersion in a thick, pasty material which is being driven outwards at each contraction of the gut. It thus seems evident that the small and delicate processes of the villi may be continually on the stretch, at first looped round tightly by a worm, the coil may then relax, blood may enter the capillaries, only to be compressed anew and so on, conditions which cannot but produce congestion on a large scale if multiplied a sufficient number of times. So far as the appearance of the esecum in disease (Strongylosis) is con- cerned, the following rough, laboratory notes describe some of the J Examples types : of Strongy- (No. 1908.) Found sick. The csecal mucosa not very red, but whitish, pale, the cseca full of mucus, and innumerable Trichostrongylus. Congestion apparent in the mesenteric vessels but no marked villous engorge- ment, only mucus in excess. (No. 1875.) Trichostrongylus very abundant, but no excessive amount of villous engorgement. Contents of cseca almost nil, this may account for subsid- ence of engorgement and reduction of redness. (No. 1854.) Cseca very badly engorged at lower open ends, but less towards centre. The whole gut swollen, foul and unwholesome, and Tricho- strongylus very abundant. (No. 1844.) Cteca much swollen and very full of material. Excessive villous congestion and redness. Abundant Trichostrongylus. A hard con- cretion at the blind end of one csecum shows that matter may remain there sometimes for lengthy periods. The whole venous system intensely con- gested, and the swellings on the csecal ridges exceptionally red with engorged villi. (No. 1842.) Caeca very much swollen, villous redness much marked, and very deep in colour. The whole contents lumpy and irregular, soft_ and hard, partly dried up, so that from without whitish lumps showed through. (No. 1839.) Cseca very large and unhealthy, thick with whitish mucus. Red 122 THE GROUSE IN HEALTH AND IN DISEASE engorged villi showing up against white fatty-degenerated mucosa and gut walls. Trichostrongylus very abundant. (No. 1728.) Villi red and engorged with blood from one end of the caeca to the other, and the redness especially marked on the swellings along the longitudinal ridges. (No. 1914.) Caeca swollen with mucus, pale and translucent. Only a few red villi, but very large numbers of Trichostrongylus, and innumerable ova. (No. 1215.) Very full of shed mucous cells, or unwholesome, yellow mess, but no active inflammation. Plenty of pigmentation in minute dots. Trichostrongylus very abundant. (No. 1827.) A very unhealthy swollen condition with villi uniformly con- gested and red throughout. Trichostrongylus very abundant. Contents of caeca clotted and adherent. No redness except in the caeca, though both cestodes were present in some numbers. (No. 1747.) Caeca with excessive numbers of Trichostrongylus; very swollen and full of clotted, tenacious, and bloody mucus. The whole gut excessively unwholesome, large and congested with red villi partly macerated, and their cells being shed. Adhesions probably post-mortem, due to crystalline precipitate in the serous fluid were to be found all along the csecal mesenteries and peritoneum. (No. 1727.) Caeca very pale, but with red villi engorged throughout. (No. 1602.) No red villi, but excessively unwholesome contents almost dry and very hard in the centre. Trichostrongylus in excessive numbers ; both caeca, very much distended, pale and swollen with mucus. The mesenteric vessels all congested. (No. 1369.) Caeca full of stiff orange - coloured mucus, beneath which the gufe is thin, red, and inflamed in appearance. Many of these cseca in diseased birds are very thin and red in the middle and upper ends, while the lower open ends contain innumerable red villi. Often it appeared as if not only cells but villi and parts of the mucosa have been shed or detached, perhaps because the mechanical strangulating movements of the Trichostrongylus leave little but the basement-membrane and the wall of the gut, , which are there almost transparent. One abnormality occurred in connection with one caecum of No. 1266, namely, an intussusception of the free blind end which has a free mesentery. It was PHYSIOLOGY AND ANATOMY OF RED GROUSE 123 involved in the attached portion of the caecum until only a portion of the blind end remained visible, and this was black and gangrenous, or nearly so. There was very little sign of Strougylosis. The bird was shot, and was in good condition. With regard to other organs of the body of the Grouse there is more to be said of the lungs than of any other. On this subject the reader * Pathology may be referred to chapter xii.. where Dr Cobbett and Dr Graham of the r Lungs. Smith have described in detail the appearance of really fresh lungs, exposed in birds just dead, and their appearance after being more or less stained by post-mortem fluids and decomposing blood. The figures which were prepared with the view of illustrating this difference could not be reproduced in the Report owing to lack of funds. The first series of figures represented the lungs of fourteen Grouse removed at various periods of time after death, and showing marked staining of the tissues. The second series represented the lungs of eight pigeons removed also at various periods after death, and showed the same or very similar ances in lung due to staining in all cases where the lungs were allowed to soak in blood- post-mortem stained, 'post-mortem fluids, as is the case in the majority of Grouse which have been shot or bruised, or even carried for many hours over a rough moor in a keeper's pocket or net bag. Even without preliminary bruising or damage there will be found a certain amount of soaking and discoloration of the lung tissues after death. In very bad cases of Strongylosis, such, for example, as No. 1228, the lungs even on the third day after death may be perfectly normal in appearance, and with- out any marked post-mortem staining. The lungs of birds may, of course, have received some damage, either by shot pellets or by broken bone splinters, and may have recovered with cicatrices, or with part of the lung solidified by organisation of the blood clot into fibrous tissue. Or blood may have been inhaled by the trachea, and so have blocked part of the lung, producing collapse and solidification. It is wise, in every case when a bird is found dead, to examine the mouth and see whether there has been any bleeding from the lungs. It is unnecessary here to repeat the discussion upon the question of " Grouse Disease" and pneumonia. For this reference must be made to chapter ix., where reasons are given in full for the belief that Klein's explanation Grouse .of "Grouse Disease" as an acute infectious pneumonia is not the correct one. 124 THE GROUSE IN HEALTH AND IN DISEASE The normal colour of quite fresh healthy lung is a very clear pink, almost a whitish pink until the organ is cut into when it is found to exude bright red Lung quite blood, and the cut surface therefore immediately becomes bright red. diseased 111 ^ ne appearance of fresh lung in bad cases of Strongylosis does not, according to our experience during the past six years, vary at all from the appearance of the lung in health, and there is no sign of solidification or of the earlier stages of pneumonia, congestion, or infiltration in the lung as a symptom of the disease. Pneumonia proper must be an exceedingly rare disease in the Grouse, and probably ninety-nine out of every hundred diagnoses of it are the result of a failure to realise that post-mortem staining and infiltration give an appear- ance which may be mistaken for pneumonia. But it is exceedingly difficult to find even a very small piece of this so-called pneumonic lung which will not float in water, and this is a fairly reliable rough - and - ready test for consolidation. In Grouse No. 1260 small caseous masses were found in several portions of the lung, and also adhesions to adjacent parts, but it was found on examination that two ribs had been broken on each side and had reunited, showing that a pellet or two of shot must have been the cause of the damage to the lung, which (apart from the remains of a small localised abscess here and there) was of a typically healthy colour and appearance. The condition of some very much enlarged veins ramifying over the surface of the proventriculus in this bird, which were probably taking upon themselves the duty of vessels previously damaged and obliterated by the accident which broke the ribs, are described elsewhere (see p. 166). In one or two rare cases (Grouse Nos. 899 and 900), as the result of a continued search under high power amongst the debris and fluid procured from Parasites a crushed piece of lung, a living larval nematode has been discovered found 'i 68 i n active movement. This was in a lung which had every appear- ance of perfect health both in colour and consistence, and yet was taken from a bird so sick of Strongylosis that flight was impossible. A lung such as this, which is a bright, normal, pink colour when the bird quite recently dead is opened (in the case in point the bird died in the hand and was at once examined), may yet in twenty - four hours be so much altered as to have a very deep gelatinous, patchy redness throughout. Later still some parts will turn almost black, while others remain pale ; and the observer who then sees the lung for the first time is almost certain to suspect some PHYSIOLOGY AND ANATOMY OF KED GROUSE 125 pneumonic change in the tissue. As a matter of fact, however, the change is at first superficial, and is more pronounced where the lung is in contact with the liver. The staining gradually makes its way, post-mortem, into the body of the lung, so that iu a few days a section shows fluid containing degenerating and decomposing corpuscular de'bris which has leaked into the air spaces and has produced the condition illustrated and described before now as the second stage of pneumonia in Grouse. At this stage the colonies of bacteria block the blood capillaries and form a characteristic feature ; but this is a post-mortem feature. With regard to the liver there is very little to be said. It is an organ which changes perhaps more rapidly post-mortem than any other, both in appearance and in consistence, and yet more has been deduced from its post-mortem _ Liver. appearance than from any of the more reliable indications of disease in Grouse. If the liver be examined fresh, even from a bad case of Strongylosis, it will be found to present a normally firm consistence and a healthy red colour. It is true that it may, and probably always will, partake of the general and at times localised abdominal congestion which characterises Strongylosis. But this alters its normal appearance very little when it is fresh, it may be a slightly darker red, and it may be a little more friable, but the change is hardly noticeable. The "black" and "tarry" livers may be ignored, unless they occur in birds that have only quite recently died, as being indications of no value from the diagnostic point of view. The staining even in a fairly fresh liver will often be found upon section to be very superficial and to be creeping towards the centre from the liver surface to the interior. Hence the first portion to show the change right through is always the edge of the anterior lobes. The only examples of disease affecting the liver of birds which have been examined by the Committee were cases of Coccidiosis, and even then the connection with Coccidiosis could not be established with certainty as the specimens referred to were also cases of recovery from wounds or mechanical damage. Small areas of fatty degeneration and localised necrosis have been seen in one or two cases, but have no apparent connection with Strongylosis. The liver in cases of Strongylosis may be considered valueless, from a diagnostic point of view, so far as macroscopic signs go. Microscopically it has been shown to be possibly of more importance (see chapter xii.), and the changes to be found post-mortem are fully described by Professor Klein in his work on " Grouse Disease." 126 THE GROUSE IN HEALTH AND IN DISEASE The spleen of the Grouse varies very much in size, and this fact appears to have some connection with Strongylosis. It is comparatively large in young and healthy birds, and is large, as a rule, and of a fresh, red colour oplGCUi in healthy adult birds ; bub in cases of Strongylosis it becomes very small and very dark, an appearance which is noticeable in fresh, dead cases of disease, and even more noticeable as post-mortem changes advance. The colour of the kidney in a freshly killed healthy bird is a reddish brown, a good deal paler than the colour of the liver. Normally the lobes of the kidney lie very flat against the dorsal wall of the abdomen, fitting into the inequalities of the skeleton. Fig. 9 of PI. xxxi. gives a rough sketch of the appearance of a normal healthy kidney as it lies in situ, with the testes overlying the upper lobe, one on each side. The kidneys appear to suffer very little either from the general congestion which must be considered a symptom in Strongylosis or from their function in ridding the body of poisons which are probably to be found in Kidney disease the general circulation. Only twice has the kidney shown any macroscopic change, and in each case it was due to an enlargement which in Grouse 1292 affected every lobe, but in No. 1107 chiefly the upper lobe. Case No. 1292 was a hen Grouse of 18 ounces found sick, and caught alive on 6th March 1908 in Yorkshire. It was a very thin bird, and in very poor feather ; it had Blaeberry shoots in the crop, no tapeworms in the duodenum or small intestine, but some Strongyles in the cseca, which were full of a dark greenish black slimy mess, like that which generally occupies the cseca of Blackgame, the result probably of a low ground diet of soft green leaves of clover, grass, and Tormentilla. The liver was exceedingly dark, but not enlarged and with no spots. The spleen was small (9 mm. long) and black. The kidneys were much swollen, and were brown with black markings, in spots ; but this colouring may have been due to post-mortem change. Case No. 1107 appeared to be the result of acute inflammation, the upper lobe being exceedingly swollen and enlarged, and of a rich red colour (see Plate XXXI., Fig. 10). In this case it will be seen that the testes have been slightly displaced from their normal position owing to the swelling of the kidney. PHYSIOLOGY AND ANATOMY OF EED GROUSE 127 Of these two cases, the first had been five days dead, and the other three, in August and post-mortem change had set in. The condition cannot be con- sidered in any way directly connected with Strongylosis, or more than two cases would have been found in a series of nearly two thousand examined. The testes appear often to run a normal -course of development as the breeding season approaches, however seriously the bird may be diseased. The first sign of any increase in the size of the testes is to be found Testes about the third week of February, at least in the northern half of Scotland. Further south it might be found a little earlier perhaps, but in 1908 for Banffshire the date was February 23rd, while for Durham it was February 24th. In May the testes have increased in size to twenty or thirty times the bulk they had during inactivity, and they are then white and fatty, whereas in winter they are generally small and black and deeply pigmented. Occasionally a very emaciated cock bird will be found with testes only half the normal size during the breeding season ; but, as a rule, the effect of disease on the development of the hen's generative system, both ovary and oviduct, is far more noticeable than is the case in the male. If we allow that the prenuptial moult has become post-nuptial in the male as a result of chronic parasitism, it is conceivable that the same saving of energy allows of this sexual development in the male; whereas in the female, in which the moult is prenuptial as it should be. there are no "savings" to fall back upon in the event of bad disease, and therefore the sexual develop- ment is unsupported, and none takes place. It is very noticeable that in sick Grouse hens there is no development of the ovaries or enlargement of the oviduct and cloaca, such as takes place in spring in every healthy hen. The ovaries remain small and undeveloped as in midwinter. Such birds are barren if they pair, for as a rule they cannot lay an egg, but they pair nevertheless, as every gamekeeper knows to his cost in a bad year. Such birds are often very backward in their plumage change as well, suggesting that the time may come when the hens as well as the P i umage cocks may have to don the prenuptial dress when the breeding season ^du^ased is finished instead of before it, as is the custom with the hen birds - Grouse now (see chapter iii. p. 45). .For example, Nos. 1878 and 1879 were two hen Grouse found dead of Strongylosis in May. One had put on the full breeding plumage, but was 128 THE GROUSE IN HEALTH AND IN DISEASE not laying, and the ovaries were very small, dark, and wholly undeveloped. The other not only showed no development of the ovaries, but was still almost entirely in the winter plumage, having had no strength to grow the nuptial one. Such birds are always wretchedly thin, and these weighed 15 ounces and 16 ounces respectively. We found many cases which showed that in the hen the plumage change must come first, for it often happens that (e.g., Nos. 1864 and 1870) the breeding plumage is complete and excellent, even in wasted birds of 13 J ounces and 14 ounces, whereas their ovaries are as undeveloped as in mid-winter. The suggestion that such weakly hens may achieve a nuptial plumage by a re-arrangement of the pigment in their feathers without undergoing the drain required by new growth, cannot be adopted. This difference between the male and the female Grouse is significant. It seems that, in the male, appearance may be sacrificed to efficiency, between* wnereas i n tne female appearance comes first, and the nuptial plumage plumage j s (j onne d at any cost, often to the undoing of the hen herself, at changes in cock and an y ra ^ e to the complete undoing of her power to produce an egg. There must, of course, be many sickly hens that not only don the breeding dress but also lay a modicum of eggs. They appear later in the shooting season with every sign of disease and exhaustion upon them, but yet recovering. Grouse that have survived the mortality of April and of May do not die later in the year. They become convalescent through the summer and autumn, owing to good food and better weather. There is no autumnal, mortal Grouse in outbreak of disease ; but there is an increased activity in the collection 'ooa- of birds that have been sick and are convalescent. These birds can fly, and are shot in August and September ; it is only when they are dis- covered in the bag, in the process of sorting later in the day, that they are suspected of disease, and are forwarded to the Committee for examination. Such birds are not at the point of death, but are, in fact, convalescent. They are not the birds that will be killed off necessarily in the coming winter, but may perhaps be still weaklings in the following spring. They are the birds that in the previous spring were badly hit by Strongylosis, but managed to survive April and May, and then were safe with a supply of good and varied food assured to them for at least eight months to come. 1 1 Vide chap. iv. p. 72. PHYSIOLOGY AND ANATOMY OF RED GROUSE 129 As we know much about these wasted autumn hens it is now safe to say that they may be placed in two classes : History of (1) Those that were too sick in the spring to breed at all, and p^'g 11 so remained barren. (2) Those that were not too sick to breed, but bred small clutches and reared from two to four or five young Grouse. The first class has the best chance of recovery, for with them there is nothing to occupy their attention but food and rest and their own convalescence. Probably most of these are passably healthy birds in autumn, with no sign of having suffered very badly except in their backwardness as regards change of plumage. These birds usually show a great mixture of plumages, having feathers sometimes of the preceding winter plumage, mingled with an irregularly grown nuptial spring plumage and perhaps some new feathers of the already overdue autumn-winter plumage. The second class is different. They also have a mixture of the same three plumages, but with more complete nuptial feathers, and fewer of the preceding winter plumage. They are the worst of all the sick birds seen in the autumn months. They have been less sick in the spring than the barren birds, but they have been worn out completely by the effort to nest, and by the cares of their family. They have nevertheless won through, thanks to the summer and autumn food supply and summer weather, and by the autumn they are convalescent. By January they will in all probability be once more comparatively strong and healthy, but not so well prepared to meet the critical conditions of early spring as those included in the first class. These, probably, of the second class are the birds that form the first class in the following year, or perhaps they cannot even rise to that, and fall victims to- the spring mortality. VOL. I. CHAPTER VI THE WEIGHT OK GROUSE By Edivard A. Wilson THE weight of Grouse in connection with "Grouse Disease" deserves more attention than it has yet received. It is a useful indication of the health of a moor, and in the early days of spring a dead bird found and weighed often affords the best rough guide for making a diagnosis of the probable cause of the trouble. Later, indication when dead birds are found in large numbers, the test becomes con- vincing if indeed any further proof as to the cause of death is required. Even in November and December a very fair indication of the probability of disease in early spring may be obtained by putting a number of birds upon the scales. A really low average weight in these months is undoubtedly a bad sign, and makes the prognosis for the ensuing year unfavourable ; while a good average weight, even if the pigmentation of the plumage is unsatisfactory, need give no cause for alarm. Apart from its practical value there are sundry points connected with the study of the weight of Grouse in health and in sickness, which are in themselves interesting ; and many facts in the life-history of the bird are found upon examination to be correlated with a normal change in weight from one season to another. It is obvious that before we can usefully investigate changes of weight in sick or dying birds, and can understand their meaning, the seasonal fluctuations of weight in health must be accurately determined and understood. Beginning, therefore, with healthy Grouse, it is found that sex is a primary factor in determining the weight of an individual bird. An adult Seasonal coc ^ Gr use is as a rule heavier than an adult hen, when both are tiontin we ^ g row11 an d i n really good condition. This is true all the weight. vear roun( j ) except in spring, for at this time when the hen begins to sit she is heavier and in better condition than at any other time 130 THE WEIGHT OF GROUSE 131 SEASONAL VARIATION IN AVERAGE WEIGHT OF HEALTHY GROUSE. (A) OUNCES JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SR ocr. NOV DEC. 25 - 24- 53 _^\ ff57 ^A 31 J<^ 25 32 A 13 VN> - - PJ ^~ _^" 17 A X HEALTHY fnfK 22 \ / / ^ s -' 19 \ ^X X LULn BIRDS 21 V ye V / 20 IIZ 19 18 (B) 25 V'-v 24 25 j- t~~ / ...7 \ HEALTHY LJ r- At 22 10 / f \ \ \ HEN BIRDS 21 {.. "" J 10 \ ffOf 84 1? , gZ. 20 \ \ \ * / / ^ ^ ^ ' / 19 ^ / / ~^ *v 17 18 (C) ?S m * /Vi/'/i'O 24 ^"\ m ^v* V^ LULno 25 --^ \ B .-- A / 22 \ 4 \ \ X /^ HENS 21 .--' -v IgiM Tflfflw/s V r'~ 20 &J&& 1 , \ i i ^--* / / / --^ ^^ f / 19 fl I ^ / / --.' "-.' 18 im, Note. The figures at the apices of the curves represent the number of birds weighed each mouth. 132 THE GROUSE IN HEALTH AND IN DISEASE of the year, while the cock is not at his best. There is, therefore, at this season, a tendency for the average weight of both sexes to approximate, and even for the advantage to be on the side of the hen. The difference in the fluctuations of weight between the cock and the hen bird is shown in the Tables A, B, and C, p. 131. The immediate reason for this difference in spring is probably the one which naturally suggests itself; viz., that the exigencies of courtship have a precisely opposite effect upon the male and female. In December, the adult cock Grouse's weight averages 24 '22 ounces, compared to 21 '07 ounces for the hen, while in January it is 23 '5 8 ounces compared to the hen's 21 '52 ounces. These may be considered normal averages, the difference at this time of year being dependent wholly upon a sexual difference of size and build, body and bone. In other words, when the birds are all living under healthy conditions, and when the sexual instincts are in abeyance, the hen being less in all her measurements than the cock has a weight correspondingly less by 2 or 3 ounces. It is, therefore, essential that average weights, to be of use in making a prognosis or a diagnosis of disease, should include the sexes separately ; and also if the weights be taken in August, September, and October that every bird taken for an average be adult. As winter proceeds, we may assume that, unless the weather is unusually open, food becomes less abundant, or, at any rate, less easily obtained and Winter ^ ess nutritious ', " the sap goes out of the heather," as it is generally feeding. expressed, and there is a large proportion of dry, dark, woody, weather-bitten shoots. Data are elsewhere given to prove that the quantity of such food, both by weight and bulk, found in the crops of full-fed birds in winter, is much in excess of what is usually found in the crops of similar birds in summer. In winter, the- crops of Grouse often contain five times as much food-stuff as they ever contain in summer. 1 And, although several factors are at work to produce this difference, one of the most important is the necessity of eating a greater bulk of winter heather in order to arrive at the same total of food value in the end. Calluna heather is eaten almost exclusively throughout the winter ; though Blaeberry stalks and Blaeberry leaf-buds often replace heather, where they 1 Vide chap. iv. p. 79. THE WEIGHT OF GROUSE 133 are abundant. Heather seed - heads are eaten in preference to the shoots until, in January, the seeds are shed, and then the birds again fall back on the winter heather shoots. It might be expected that the weight of Grouse would suffer from the shortage of nourishment contained in the winter food : but, as a matter of fact, the average weight of both sexes gradually increases during the winter months until March, the worst and most trying month of the whole year for Grouse. February, March, and April must be considered months of greater or less starvation every year, since the winter food has been picked over, not only by the Grouse themselves, but by cattle, sheep, deer, and hares, and often, too, the whole moor has long been buried deep in snow, or the heather has suffered badly from frost or from the dry parching effect of north-east winds. Sometimes the roots have been frozen in the surface soil, and the soil has been too cold to allow even a drain of sap to rise, so that the Grouse are hard set to find food enough to maintain their weight. Although the hen appears able to remain in good condition, the cock always loses weight to some extent at this time often far too much and in consequence suffers from a diminished power of resistance to Entozoa. When thus half-starved, and long before he has any chance of recuperation, the exhausting necessities of courtship force themselves upon him. The cock bird in February is still in full winter plumage, and by March, though he possesses well-developed supraorbital combs, these alone of all his attractions can be considered a special addition to his winter dress for courtship. These crests or combs over the eyes are erectile organs of a brilliant crimson colour, and inconspicuous or even invisible as they are when the bird is at rest, they become in excitement so erect and tense as almost to meet above the top of the head. They are then visible from afar, and are indica- tions of the nervous tension of the breeding season. The bird is at this time bold, noisy, aggressive, jealous, excitable, pugnacious, and magnificent to see. He struts, becks, flies constantly about from one hillock to another, defies all comers, fights viciously, eats little, and constantly attends his mate. Throughout February and March he leads this exhilarated but exhausting and unsettled life, constantly at war, and daily becoming more and more reduced in weight. In addition to all this, he is probably loaded up with parasites, and, though he may live to recover, the strain is often too great, with the result that it is in April and May that the majority of cock birds die of disease. 134 THE GROUSE IN HEALTH AND IN DISEASE With the hen, however, it is very different, for at this time she leads an even quieter life than usual. She feeds constantly, takes no part in the warfare of her mate, and becomes to a greater or less extent " broody." When Hen in * breeding in this condition she does not readily take the wing, and puts on flesh season. and fat. By the time she begins to lay she has a very large store of surplus fat deposited throughout the body and in masses under the skin ; and from this reserve she draws during the three weeks of incubation. For the twenty - three days during which she " sits " she leaves the nest only for a few minutes night and morning, to eat and drink, and her tracks and "clocker" droppings are to be found always at the springs or drinking-places, which happen to be nearest to her nest. At the beginning of the nesting season the hen Grouse weighs as much as a heavy cock, sometimes even up to 27 ounces ; but this holds good for a short time only. It is just during these two months of the year, April and May, that she suffers most from " Grouse Disease " ; an inexplicable fact, did we not know that for various reasons, which are given below, March is to be considered the most dangerous month of the whole year for infection with Strongylosis. As the hen sits, her weight, even in health, rapidly diminishes. She is living largely upon her reserve material, and has, in addition to produce from eight to ten eggs. This must be a very considerable drain upon her system, since each egg weighs about an ounce, and each ounce so lost to her is an ounce of her " flesh and blood," the whole amounting sometimes to nearly half her eventual total weight. By the end of June, thanks also to the trials of a family, she reaches an average weight of less than 20 ounces, and by the end of July sometimes falls to 19'5 ounces, whereas the cock, benefiting daily by the improving food and weather, gradually rises from 19 or 20 ounces in March to an average of 24 ounces in August. 1 It will perhaps throw light on the cause of the marked changes which appear in Tables A and B if an attempt is made to account for them month by month. In Table A, for example, which gives the monthly averages for the healthy male Grouse, there is a very decided fall from 24 '2 ounces in February to 21'45 in March, with a gradual rise again from April to August. This sudden drop must be due to courtship, rather than to shortage of food, for though food is scarce at this time the shortage makes no difference 1 Vide p. 145, note. THE WEIGHT OF GROUSE 135 worth noticing in the case of the hens (see Table B). This argument is borne out by the almost equally sudden rise as soon as the mating is over. The post-nuptial moult in the male takes place in April and May. It is complete in June, therefore any loss of weight in the replacing of new feathers would make itself felt in the earlier of these three months. From April to August the food supply is improving daily, and the weight of the cock Grouse gradually increases. And it is by no means easy to see why there should be a sudden drop in September unless it is due to the complete (male) moult to the winter plumage. As there is no corresponding drop in the hen, and, as we know, no similar moult, we are probably right in thus attributing for the September fall in the weight of the male to this autumn moult. 1 It is, however, true that although healthy Grouse are at a much lower ebb, as evidenced by their average weight, during certain months of the Relation year than during others, Strongylosis does not necessarily kill them diseaseTnd off at these seasons. It kills off the hens when they ought to be wei s ht - at their flood tide of health and vitality ; and the cocks when they ought to be on a good rising average tide. We have thus a paradox which may be stated in the following way : More hens die of Strongylosis during April and May than in any other month of the year, notwithstanding the fact that the healthy hen is then at her best so far as weight, fat, and plumage go. More cocks die of Strongylosis during April and May than in any other month of the year, notwithstanding that the healthy cock is then already recovering the weight which he lost during courtship, and is at a fair average and rising weight. And although one might expect cock birds to die, in March and September, when the average weight is at its lowest, this does not occur. And whereas one might expect hen birds to die in June and July, or in November, when the average weight in health is at its lowest, this also does not occur. In attempting to explain this paradox, it is necessary to recapitulate shortly the conditions which lead to an over-infection of the Grouse with the young Trichostt -ongylus. Elsewhere it has been pointed out that, owing to the small proportion of 1 The cock Grouse normally moults twice a year, first between April and June, and secondly between August and November. The normal hen Grouse also moults twice a year, first between February and April, and secondly during July and August. 136 THE GROUSE IN HEALTH AND IN DISEASE heather which produces good food during the months of February, March, and April, all the birds upon a moor are forced to concentrate upon small areas Cause of f feedin g g^nd. 1 Consequently, there is a tendency for these small fnfecUon 6 areas to become heavil J infected with the Trichostrongylus even from the droppings of healthy birds. At first there are no evil results, for the eggs take some weeks to go through the necessary stages of metamorphosis before the worms become actively dangerous to the health of the bird. 2 Thus, even by the end of February and beginning of March, there is compara- tively little mortality among Grouse. 3 As time goes on, however, the infection becomes more and more intensified, for not only do the larval nematodes assume their most active form, but those which have been eaten by the Grouse at the beginning of the period have had time to grow up and produce eggs in the intestine of their host, and these eggs are in turn distributed over the moor to add to the moor infection. The unhealthy conditions do not result in immediate mortality it has been shown by experiment that birds which have been fatally infected may not die for many weeks. 4 In some cases a severe infest- ment does not result in death. 5 Even in March the mortality has not reached its height, 6 for the majority of birds fatally infected in March will probably not die till April. The infection of the ground continues to increase, and if the same conditions were prolonged for another month or two it is possible that on the majority of moors hardly a bird would survive. Fortun- ately the advent of spring brings a blessed relief to the plague-stricken stock, and with the first appearance of new heather growth at the end of April and beginning of May risk of fresh infection is past. Thus it is that in April the infection reaches its climax, but the birds which die in April are probably the result of infection in March, whereas the birds infected in April die in May, even although the conditions have improved. This is the explanation of the paradox stated on p. 135. It may be assumed that both cocks and hens have the same opportunities for obtaining food, and that the quantity and quality of that food is the Power of same for eacn , consequently each will be equally liable to infection ce - by the Strongyle worm. Why then do the cocks die in larger numbers than the hens 1 Only one answer is possible, and that is, that whereas at this time the power of resistance of the cock is at its lowest, the power of resist- ' Vide chap, iv p. 81 * Vide chap. x. p. 224. i Vide Chart F, p. 142. Vrde, vol. 11. Appendix F. = Ibid. e Vide chart ^ U2 THE AVEIGHT OF GROUSE 137 ance of the hen is at its highest. The fact is sufficiently proved by the com- parison of the weights of the sexes, but if further confirmation be required it would be found in the fact that in June as the cock increases in weight so he becomes less liable to disease, whereas the hen, whose weight is on the downward grade, continues to suffer, and sometimes to die, throughout the summer months. The fact that the average weight of the cock is slightly on the upward grade during the months of greatest mortality is somewhat misleading, unless it be remembered that he is still far below his best condition, and was probably about his worst at the time when he first contracted the infection. The reason why cocks do not die in September, or hens in November, when their respective weights are again at their lowest, is obvious mere loss of condition is not enough to cause death. It is only where this loss of condition is found in conjunction with a heavy infection of parasites that it becomes a source of serious danger. To return, however, once more to the healthy bird, it is to be remembered that in June the hen undergoes a complete post-nuptial moult, changing from the now faded breeding or nuptial dress, to the autumn or summer plumage, and this she cannot do without an appreciable drain upon her resources. In changing the winter plumage for a nuptial breeding dress in January she differs radically from the cock, who retains his winter plumage until the breeding season is over. The two sexes moult at different seasons, and each twice within the year. The details of the changes have been carefully investigated and described by Mr Ogilvie-Grant, and have been dealt with in another chapter of this Report. 1 It has been pointed out that the cock bird begins to grow new feather iri March and in August ; whereas the hen bird begins to grow new feather in February and July ; and each of these moults appears to have a Effectg of definite effect upon the weight of the bird. There are, therefore, moult - fluctuations in the weight of the healthy Grouse, which are partly due to the moult, and are therefore seasonal, while others are purely sexual ; it must be noted that the seasonal fluctuations differ as to date in each sex. Both seasonal and sexual changes occur in normal healthy birds. These fluctuations must be fully recognised before any useful deductions can be drawn regarding the changes of weight in birds that are or have been diseased. 1 See chap. iii. p. 34. 138 THE GROUSE IN HEALTH AND IN DISEASE The effect of the various influences which affect the weight of the healthy Grouse are shown in Tables A, B, and C. 1 It is unfortunate that some of the monthly averages have been taken from such a limited number of birds. This, in the breeding season, is unavoidable. There is a very natural objection to the wholesale destruction of healthy sitting hens for any purpose. Even dead birds are less likely to be found at this time of year than at any other, for the reason that the majority of gamekeepers dislike the disturbance of their moor which is entailed by a systematic search. It is partly to this feeling amongst keepers that one should attribute the prevalence of the belief that " Grouse Disease " mortality is confined to the spring and autumn with a break between. There is no doubt that the least observed and least understood portion of the life cycle of a Grouse moor is that which lies between May when the early broods are hatched off and the end of July, when the dogs are taken out to make a survey of the shooting prospects. Conversely, too, from the intimate knowledge of the moor after August 12th, undue importance has been attached to the idea of autumn disease owing to a certain number of sickly birds being found in the August and September bags birds which would otherwise have escaped notice altogether, but which were shot in the day's sport, and afterwards picked out as "piners." The point is clearly shown by Charts D, E, D 1 , E 1 , p. 139. It is by no means a rare thing to find hens weighing 14 and 15 ounces still Weight as ca P a l e of flight. Often such birds are shot and afterwards picked tioiTcrf Ca out f *h e *> a g as " piners " to be examined, and condemned as cases disease. O f Disease. The appearances of ill-health are generally abundant. To begin with, the bird is undersized, the bones are found to be unusually small in their measure- ments and slight in their structure, suggesting that the bird was bred late in the previous year. This gives it a bad beginning, and means that the bird, lacking strength, suffered more than the early bred birds during the previous winter months. If the bird is a hen, it will be evident from the naked skin of the abdomen, from the delayed moult of the feathers of the upper parts, and from the almost featherless condition of the legs and feet, that a long and exhausting period of incubation has been endured, followed by a period of incessant watchfulness while the young brood required protection. Often enough a hen "piner" in this condition appears to have suffered from no more definite Vide p. 131. THE WEIGHT OF GROUSE 139 CHART'S SHEWING THE FALLACY OF THE AUTUMN OUTBREAK OF DISEASE. NUMBER JAN. FEB. MAR. APR. MAY JUNE JULY AUG. 5EP ocr NOV. PEC. IOO (r\\ 90 (D) so y* 7O / \ 6O / \ NUMBER OF SO f \ Cocff BIRDS to / 3O / \ DEAD. 20 / \ to / Y .. _ / i . 9O eo (E) 7O 6O N//M 'Rf/? n& SO A 4Q / \ yv^ COCK S/ffos 3O / ^ / "-x , SICK ONL Y. ZO / \ / '^.^ IO / V ~7 ^ , " -. SO SO fo) 7O 60 .. NUMBER OF to HEM B/ffOS JO -"N, DFAf} 2O z V 10 - - -_ . i 9O (r- I \ SO E') 7O A 60 /\ NUMBER OF SO f \ HEN flj&n^ to / L. JO / \ SICK ONL Y. 2O ^+^ J N v^ IO _^x ~- ' _ s_ fl_ __*- i - T disease than this over-sitting. This in a weakly hen is in itself a sufficient cause of extreme emaciation. Then, again, it may be found that the bird is replete with parasites. These, if the case is a true " piner," will be abundant within and without. The feathers are often alive with Nirmus and Goniodes, the small flat Bird Lice, and the head of the bird is dotted, especially round the eyes and ears, with Ticks of the genus Ixodes. The presence of Ornithomyia, the Grouse fly, depends more upon the weather and season than on the condition of the host. Within, the duodenum will be occupied by a mass of Hymenolepis (tapeworms), or Trichosoma (threadworms), or both ; the main gut by a far more bulky mass of Davainea (tapeworms) ; and the coeca may be reddened from end to end by 140 THE GROUSE IN HEALTH AND IN DISEASE villous engorgement due to the irritating presence of thousands of Tricho- strongylus (threadworms). In this state the bird is flushed and shot, and forwarded for a diagnosis. And still one more perplexing item, namely, that scattered here and there amidst a hundred thousand Trichostrongylus ova, in the contents of the intestine, are encysted spores of Coccidia, showing that the bird may have lost weight in the height of the summer by excessive Coccidiosis, and yet have survived. Our investigations have established that one form of sickness commonly called " Grouse Disease " is due to the excessive infestment of Grouse by Trichostrongylus, and the most easily recognised symptom of this disease is loss of flesh and weight. It is for this reason that the average weight of birds is the best indication that can be obtained of the prospect of health or disease upon a moor in the near future. The tradition, for it is probably nothing more, that in some outbreaks of " Grouse Disease " birds have been found dying or dead well up to weight is discussed elsewhere. 1 Birds do not die of Strongylosis without exhibiting loss of flesh and weight. Neither do Grouse chicks die of Coccidiosis without losing weight. Beyond these two diseases we have no knowledge of any other disorder which attacks Grouse over considerable areas of country, and kills them in large numbers. The reason for this loss of weight in Strongylosis and Coccidiosis can be seen when a diseased bird is dissected. The post-mortem appearances are fully described in other parts of this Report. 2 The following list includes most of the conditions which commonly " affect the weight of Grouse :- I. IN HEALTH. (a) Sex, generally in favour of the male, but in April and May rather to the advantage of the female. (6) Late hatching, producing birds of both sexes unready for the winter; birds which have missed the best growing months of summer, and which therefore remain permanently undersized and of a poor physique though not actually diseased. 1 Vide chap. ix. pp. 204 et seq. 2 Vide chap. xii. p. 288 ; chap. xi. pp. 257 et seq. THE WEIGHT OF GROUSE 141 (c) Moult, in the male taking most effect in March and in September ; in the female in July and November ; probably always leads to some loss of weight in either sex. (d) Courtship, in the male always apparently a cause of loss of weight : in the female, owing to increased rest, with some change in the general metabolism and extra opportunities for feeding prior to incubation, seems to lead normally to a very considerable increase of weight. ($} Egg laying and incubation, gradually lead to a loss of weight, which becomes more marked when the hen has had the care of a family of chicks. These cares, notwithstanding the abundance of summer food, often result in producing the lowest possible weights in hens, such loss of weight being in some cases due to an attempt to rear a second brood. During the hen's incubation the cock somewhat recovers his weight, possibly because the food supply is rapidly improving, and because his energies are not so exhausted by courtship. (f) A shortage of good food in a bad winter must often be responsible for a great reduction of weight, and indirectly for an increase of the mortality in both sexes due to Strongylosis in the spring. Similarly the abundance of food in summer, autumn, and early winter must serve to counteract some of the other causes of loss of weight. II. IN DISEASE. (a) Strongylosis in both sexes and at all ages leads to excessive loss of weight, and ultimately to death, but the maximum incidence of infection is strictly seasonal, accounting wholly for the fact that both sexes die in April and May in very much greater numbers than in any other months of the year. The observation that so many more cocks die than hens has been explained largely by the fact that the average power of resistance of the normal hen Grouse is at its best in April and in May ; while that of the normal cock has just been at its worst. Another factor which bears on this question is shown by refer- ence to Chart F, p. 142, which shows the average monthly weight of cocks and hens found sick but alive and found dead of Strongylosis 142 THE GROUSE IN HEALTH AND IN DISEASE respectively. This table has been prepared to illustrate that birds found sick show the same tendency to lose weight though they do not record such a marked loss as those which have actually succumbed to disease. CHART F COMPARISON OF AVERAGE WEIGHT OF SICK BIRDS AND OF BIRDS FOUND DEAD; BOTH OF STRONGYLOSfS. OUNCES JAN. FEB. MAR APR. MAY JUNE JULY AUG. SEP OCT. NOV DEC. m 21 20 19 f ; / X "-v \ ** . MAIE. SICM B/aas. 18 / /H K~ > X' N --. --*H . 17 '/ ^ " *. x ''-**- *""- . FMAlS- S/CMB/eoS. IK T&^ V. 5*v ^ *-<& ^ ^^ \ g'lALESFDUND DEflO. 15 ' \ s 7^ ^ \^ ^ V*' y FEMALES. FOUND Of/ID. 14 \ / \^ ^ / 13 V V/ 12 The curve shows that birds succumb at very different stages of emaciation, in different months of the years. For example, in the case of the cocks a bird will die at 20 ounces in February, at 19 ounces in March, at 18 ounces in April, at 17 ounces in May, and at 16 ounces in June the conditions of weather and food making life easier month by month as warmth, sunshine, and increasing abundance of food enable the sick bird to cling to life a little longer. It is interesting too to note that in the case of the hens, although the average weight in health is 23 to 24 ounces in April and May, it falls in fatal disease to 16 ounces, whereas the cock bird, whose average weight in health is also 23 to 24 ounces for the same two months, succumbs at 17 '5 to 18 ounces. (6) General Helminthiasis, including all disorders due to worms in birds of both sexes and at all ages must also have a share in causing loss of weight: (1) by disturbing the normal digestion and THE WEIGHT OF GROUSE 143 assimilation ; (2) by the production of toxins in the alimentary canal, many of which are absorbed by the blood ; and (3) by (but this is a minor matter) the worms absorbing, living on and growing on food which in their absence would have served to nourish their host. (c) Coccidiosis, especially in young birds, causes excessive emaciation and frequently death. 1 It would be interesting, were it possible to collect sufficient figures, to compare local variation in the average weight of healthy males or females with local differences in the height above sea-level, the rainfall, the character variations of the subsoil, or the prevalence of disease. For this purpose it would be reasonable to take wide natural divisions such as those which are plotted out for meteorological records, in preference to artificial divisions such as county boundaries and political districts. In attempting this, however, it must be remembered that for a number of years it has been the practice to introduce birds from one part of the country to another, perhaps a hundred miles or more away. This practice makes it difficult to trace true local variations either in size or in other characteristics. It is true that particular districts have been credited with the production of birds distinctly above the average in size and weight. Midlothian, Caithness, and the west coast of Scotland each claim to produce Grouse of a high average weight. To establish this a much more extensive series of weights should be taken than has hitherto been possible. So far as the Committee have been able to ascertain, it is difficult to say with certainty that any one district produces birds of a definitely larger type than any other. The result of the evidence collected is given in the form of a Table on p. 144. 1 Vide chap. xi. pp. 252 et geq. [TABLE. 144 THE GROUSE IN HEALTH AND IN DISEASE TABLE SHOWING AVERAGE WEIGHT OF GROUSE FROM DIFFERENT DISTRICTS. Cocks. ] Sens. County. Date. S.S-S laS S -D fco ii *! II S . 11 W sL 3? fS 9 tH (B-O I-H.S 5$ f.'SJs S.S 53 * ~ s-a Ii %* In SM n 41 Is MM J SCOTLAND 1. Caithness Various 14 Ibs. ozs. 20 10 ozs. 23-6 ozs. ozs. Ibs. ozs ozs. ozs. OZS. 2. Sutherland, No. 1 Moor 2 3 , 4 , 5 , 6 , 7 , 3 , 9 , 10 , 11 , 12 Aug. 24 ,, 24 ,, 24 30 24 24 23 26 22 ,, 26 23 12 12 20 20 12 20 12 20 12 12 12 10 19 1 18 29 8 31 18 27 10 17 13 30 3 18 3 18 17 5 14 5 25-4 24 23-6 24-8 24 22-1 237 1 24-1 24-25 24 23-1 22-9 ... 12 12 20 20 12 20 12 20 12 12 12 10 16 15 6 26 30 16 24 8 15 6 26 2 16 13 15 15 10 13 7 21-3 20-5 20-8 24 21-3 19-6 20-5 20-9 22-4 20 20-8 21-5 Average for County . 174 259 23-9 174 230 4 21 3. Ross-shire, No. 1 Moor i 2 ,, 16 3 12 4 8 19 24 25-3 2 12 2 12 16 22 21-3 Average for County . 15 23 8 25 14 18 12 21-4 4. Inverness 98 148 2 24-35 4a. Skye .... Aug. 24 1 23 23 5. Moray .... 4 5 13 23-37 6. Banff'shire 16 10 15 1 24-1 10 12 14 20-6 7. Aberdeen, No. 1 Moor ii ii 2 ,, It II 3 ,, >i ii * 12 12 12 12 19 8 18 18 94 20 2 26 24 24-7 26 8 ' ' ' ... 12 12 12 12 16 5 16 1513J 16 4 21-7 21-3 21-1 21-6 Average for County . 48 76 3J 25 48 64 6^ 21-4 S. Kincardine . 12-14 32 23-23 25 19-9 9. Forfar .... ... 12 19 25-3 12 16 21 3 10. Perthshire . j , . . ii . II . . . J ) . ,, . . . , 14 , 16 , 19 , 20 , 22 , 24 , 27 17 18 16 4 8 2 8 ::: 23-4 23-5 23 23 24-4 23 24-6 28 24 26 24 26 23 27 19 23 18 21 23 23 23 10 9 10 3 2 8 4 20-2 20 20 18-6 20 20-5 22 22 24 24 20 21 24 23 19 16 18 17 19 18 20 Average for County . 73 23-5 46 20-2 11. Stirlingshire . ,, 14 1 1 8 24 ii 21 1 1 4 20 i> ... ii . ii ... ii ... ,, 31 Sept. 28 Nov. 18 Dec. 7 12 4 9 7 18 10 6 2 12 2 10 5 24-8 24-5 21-5 23-5 28 25 26 26 23 23 18 21 8 4 10 8 11 4 15 12 1 10 5 22 19-7 19-3 20-6 23 22 22 24 21 18 17 18 Average for County . 33 48 11 23-6 31 39 9 20-4 General avenge weight of full-grown Grouse at commencement of shooting season : Cocki, 23-6" ox. ; hem, 20'65 oz. THE WEIGHT OF GROUSE 145 TABLE SHOWING AVERAGE WEIGHT OF GBOTJSE FROM DIFFERENT DISTRICTS. continued. Cocks. Hens. County. Date ||f if if .1-d IS n II fc of* o.t II $ I 5 fl SCOTLAND 12. Argyllshire . Aug. 12 13 15 16 20-24 20-24 14 13 12 5 10 12 12 12 Ibs. ozs 18 ozs. 23-7 24 24-4 24-2 24-5 25-5 24 ozs. 27-5 ozs. 14 11 6 3 12 12 Ibs. ozs . ozs. 20-5 20-4 21-3 22 21-25 22-5 ozs 22 OZS. Average for County . 76 18 24-3 27-5 ... 58 21-3 23 12. Mull . . . . Aug. 16 1 25 25 13. Fife . 43 62 8 23-27 14. (Dumbarton) 12-20 12 23 12 21 ... 15. Midlothian . 5 7 4 23-25 16. Haddington 14 20 12 23'78 . . . 17. Arran . 5 7 10 24-45 18. Ayrshire 10 24 10 20 19. Lanark ... 1 1 9 25 20. Berwickshire 19 12 18 24 12 16 21-3 21. Dumfries 8 10 6 20-78 22. Roxburgh . 3 4 8 24-33 23. Peebles 30 24. Selkirk ... 24-6 26-5 21-2 23-5 25. Kirkcudbright 1 21 26. Wigtown 1 24 ENGLAND 27. Northumberland . Sept. 10 12 18 15 25-25 12 15 12 21 28. Durham ... 5 8 25-6 4 5 20 29. Cumberland 1868, Sept. 17 28'5 ... 1873, 5 28-5 Average for County . 28-5 30. Westmorland 10 14 5 22-97 31. Yorkshire . Aug. 12 12 23 About Aug. 17 Aug. 23 10 10 10 20 12 15 8 15 7 1411 29 8 18 6 24-8 24-7 23-5 23-6 24-5 10 10 10 20 12 14 8 13 4 1312 25 8 16 1 23-2 21-2 22 20-4 21-4 Average for County . 62 93 8 24-2 62 83 1 21-5 32. Derby .... 13 15 28 24-5 15 20 21-3 WALES 33. ,, 13 20 29 10 23 7 27 22 20 26 9 21-25 24 19 IRELAND 34. Donegal 1 25 8 25 50 General average weight of full-grown Grouse at commencement of shooting season : Cocks, 23-97 oz. ; hens, 20*65 oz. VOL. I. K 146 THE GROUSE IN HEALTH AND IN DISEASE The heaviest cock Grouse which came before the notice of the Committee was one of exactly 30 ounces from Peebles. Macdonald, in "Grouse Disease," 1 says : " The Grouse in Scotland is a larger and finer bird than that met with in England," a remark which the above figures do not altogether uphold. Macpherson, in Fur and Feather Series, says : " The cock birds not infre- quently weigh 28 or 28-J ounces in the north of England, when in first-rate condition in every respect. Anything over 30 ounces is noteworthy, but a weight of 32 ounces is not unprecedented." 1 In Yarrell's "British Birds," 3 Red Grouse are said to be at their best, both as regards weight and plumage, in November ; but this is only partly true. Their best months are February, August, and December ; and one may say they are at a fair level of condition in those months. 1 Macdonald, " Grouse Disease," p. 103. 2 Fur aud Feather Series, " The Grouse," p. 64. 3 Yarrell, " British Birds," vol. iii. p. 77 (edited by Howard Saunders). Fourth Edition. London : John Van Voorst, 1882-1884. PART II. THE GROUSE IN DISEASE CHAPTER VII CAUSES OF MORTALITY IN THE RED GROUSE By Lord Lovat and Edward A. Wilson IN classifying all diseases it must be remembered that before it can be scientifically named it is necessary to ascertain whether the disease in question has ^3*^ an individuality which can be specifically described and recognised of disease. by definite characteristics and symptoms. It is an accepted rule of medical science that the primary cause of a disease must be found before any attempt can be reasonably made to discover a cure. Yet this important rule has been almost wholly ignored by Ascertain- * i i mentof the majority of writers upon " Grouse Disease, with a few notable primary exceptions, such as Klein, Cobbold, and Farquharson. Hardly a writer on the subject but dwells in vague generalities, hope- lessly mixing up observed facts with unsound theories, and primary with predisposing causes ; for instance, if the chief object of the writer of the following paragraphs had been to confound an already almost previous hopeless confusion, he could hardly have been more successful : " What I still maintain is that the unwholesome food which Grouse have been compelled to eat has occasioned both the worms with which they have been infested and at least one type of the disease." "The disease appeared in all its virulence after the heather had been damaged by hard frost ; but the crying evil is undoubtedly the overstocking of the moors with sheep." " Grouse have materially suffered from cold late springs which have blighted the heather." " Granting as I do that this nasty little parasite Strongylus does occasion disease in Grouse, is there anything illogical in attributing the cause of the 147 148 THE GROUSE IN HEALTH AND IN DISEASE worm to the bird being compelled to eat unwholesome food, from its natural food the heather being damaged or destroyed from continued blighting east wind ? And thus the blight of the heather is really at least one cause of ' Grouse Disease."' "Insufficient or unwholesome food is the cause at least of one type of disease amongst Grouse." Or the following : "'Grouse Disease' is caused mainly by overstocking, over-preservation, and the complete and indiscriminate slaughter of certain species of so-called vermin, notably the Peregrine Falcon ; also by the state of the young and old heather after severe and late frosts which do much more harm now that heather burning is done systematically. Also by greed for big stock. Un- natural and rapid burning of heather and a wholly artificial state of Grouse farming; also interbreeding." In the above quotations, which are perfectly sound so far as they go, we have a very fair summary of possible predisposing causes ; but the immediate cause of " Grouse Disease," whether we consider the disease to be pneumonia, or Strongylosis, or Coccidiosis, or Enteritis, or any other sickness in the world, is not touched. The primary or acting cause of Klein's acute infectious pneumonia was believed to be a sub-species of the Bacillus coli ; the primary cause of Cobbold's Strongylosis is the nematode worm Trichostrongylus pergracilis ; the primary cause of Grouse Coccidiosis is Eimeria (coccidium) avium, and so on ; not east winds or the absence of the Peregrine Falcon. Until we have discovered the active agent in a disease we cannot say that we know its cause. This is a fundamental rule, and to be satisfied with predisposing causes is to be satisfied with less than half the truth, though that half is, of course, very important if our intention is to proceed further in the attempt to discover a remedy for the disease in question. The consequences of what has appeared to be epidemic disease amongst Grouse have been so disastrous from time to time in the past that Alimor- it is not surprising to find a very widespread tendency amongst Grouse* 1 sportsmen and gamekeepers to attribute every death and every case "Grouse of sickness on the moor to the so-called " Grouse Disease." It is obvious that Red Grouse, in common with other birds, may be subject to more than one form of disease ; but when a certain form of CAUSES OF MORTALITY IN THE RED GROUSE 149 sickness takes an undisputed pre-eminence above all others for a century, as has been the case, apparently, with the Red Grouse sickness, there is some justification for the use of such an expression as " The Grouse Disease," and some excuse for the view held, by those who cannot go into the minutiae of microscopic work or of dissection, to ascribe all mortality on a moor to this one disorder. It has been the object of the "Grouse Disease" Committee to investigate this question, and to find out amongst other things : The objects (1) Whether the sickness described universally as "The Grouse of the Disease " in all the literature of the past century which deals with the subject is, in truth, a single disease with individual character peculiar to it alone ? (2) Whether a distinction can be discovered between various recorded outbreaks of the so-called " Grouse Disease " which will justify the opinion held by many writers that two distinct forms of disease, due to two distinctive causes, are confused under the one term ? (3) In the event of a finding in favour of the belief in two or more distinct epidemic diseases, what are their respective causes and effects, and by what distinctive titles and characteristics should they be known ? (4) In the other event of a finding in favour of the belief that only one epidemic disease exists, is Professor Klein's view right, that the only serious disorder amongst Grouse, to which all past records of disease refer, is the one which has for its cause a Bacillus of the B. coli group, and for its chief morbid characteristics the lesions of an acute pneumonia in the lung, and "all the characters of an acute infectious epidemic disease"? Or, (5) is Dr Cobbold's view right, that there is a pseudo-epidemic disorder amongst Grouse, answerable for all the recorded outbreaks of disease, which has for its cause a nematode worm of the genus Trichostrongylus, and for its chief morbid characteristics certain lesions in the caeca due to chronic irritation, leading to extreme emaciation ? (6) Is there any other form of " Grouse Disease " which is the cause of extensive mortality, but which has hitherto been overlooked ? These are questions which have to be answered before it can be said that we understand the forms of " Grouse Disease " sufficiently to classify them systematically. With a view to defining the main divisions under which the next five chapters are arranged, it may be well at this Com- , . , , . mittee's stage to give in anticipation a brief summary of the conclusions at investiga- which the Committee has arrived. 150 THE GROUSE IN HEALTH AND IN DISEASE The Committee is of opinion : (1) That the sickness which has in the past caused "Grouse Disease" among the great majority of adult birds is a single ^disease with clearly defined characteristics of its own ; (2) and (3) it follows that if the two forms of " Grouse Disease " hitherto described as distinct diseases are, in fact, one and the same disease, there is no longer any need to differentiate between them; (4) that "Grouse Disease" is not due to an acute infectious pneumonia caused by the presence in the lung of Klein's Bacillus; (5) that adult " Grouse Disease " is caused by the presence of Cobbold's Trichostrongylus in large numbers in the cseca ; (6) that another form of disease in Grouse exists which has hitherto escaped notice. This disease is caused by the presence of JEimeria (Coccidium) avium in the alimentary tract, and is referred to in the Report by the name of " Coccidiosis." It is improbable that Coccidiosis can have been responsible for any of the outbreaks of so-called " Grouse Disease " in the past, for, so far as the Committee's experience extends, it is only the chicks that succumb to this disease, whereas the records of "Grouse Disease" refer only to mortality among adult birds. The grounds on which the foregoing conclusions are based form the subject of chapter ix. ; chapter x. is devoted to a description of the Trichostrongylus pergracilis of Cobbold, the primary cause of "Grouse Disease" proper, and chapter xi. deals with the Coccidium avium and Coccidiosis in relation to young Grouse. We have still to discuss the less important diseases of Grouse, of which quite a considerable list may be given ; though their interest is greater from a purely academic point of view than as a serious menace to the Minor dis- ; / eases of well-being ol a moor: indeed with one or two possible exceptions, there is not much probability that they will ever give cause for much anxiety. The exceptions occur most commonly in consequence of the proximity of Grouse moors in certain districts to low-ground shootings heavily stocked with Pheasants and Partridges. It is well known that these latter birds are often the victims of various forms of Enteritis, and cases have been reported to the Committee of Grouse dying of disease apparently contracted from Pheasants which have strayed on to the moor. Amongst other causes of death may be mentioned diseases connected with the reproductive functions, diseases connected with the seasonal moults and diseases caused by deficient or unwholesome diet. But apart altogether from mortality due to disease, a large number of CAUSES OF MORTALITY IN THE RED GROUSE 151 deaths are directly or indirectly due to accident or to artificial causes. Many of these causes may be traced to the agency of man, and it will be shown elsewhere to how great an extent some of them are avoidable causes of by attention to the details of moor management. Shooting, in all its forms, is responsible for a great deal of unrecorded damage amongst Grouse ; and the examples of " pricked '' birds which have come to the Committee's notice, generally sent as "diseased" birds for examination, show amongst other . things how extraordinarily active is the recuperative power of an animal in a state of nature. Bones are fractured and reunited, even those of the wing, allowing the bird to survive, to be shot again the following year. Peritoneal adhesions may shut off a perforation of the intestine, and even result in a short-circuit of the gut before leakage has caused sufficient general peritonitis to result in death. Chapter viii. deals with the mortality and damage due to accidental causes, or to natural causes other than true " Grouse Disease," and thus clears the way for the proper consideration of the main subject of the investigation, viz., death due to " Grouse Disease." CHAPTER VIII CAUSES OF MORTALITY IN THE RED GROUSE continued By Edward A. Wilson THE causes of death and damage to Grouse not due to " Grouse Disease " may be classified as follows : A. THOSE REFERABLE TO ARTIFICIAL CONDITIONS. Accidental consequences of sport, wire-fencing, telegraph-wires, sheep-drains, vermin-traps, poison, etc. B. THOSE REFERABLE TO ARTIFICIAL- CONDITIONS. Extremes of climate ; cold, heat, wet, snow, etc. Destruction by birds and beasts of prey, so-called " vermin," and by the pugnacity of the Capercailzie and Blackgame. Exigencies of reproduction : fighting of cocks, over-sitting of hens, egg- binding, gastro-uterine, gestation, etc. Exhaustion due to moult, and to skin disease affecting the growth of feathers. Deficient diet and starvation, due to frosted, blighted, and over-age heather or to heather-pests ; deficiencies of grit and water ; excessive or injudicious burning ; and feeding on unwholesome foods, e.g., corn-stooks and sour grain. A. Causes of Death and Damage resulting from Artificial Conditions. Under this heading there are some causes which may be passed with a mere mention. Death and damage One might do so with all, perhaps, were it not for the interest from arti- i i i /^ ficial attaching to some of the cases which have come before the Com- mittee, and the light which they throw on the recuperative power 152 causes. CAUSES OF MORTALITY IN THE RED GROUSE 153 of birds in the wild state. Some of these cases occurred in birds which had died naturally ; in others the specimen had been shot, and forwarded for examination as a possible case of disease. The following accidents are within the experience of most game preservers : collision with wire fences and telegraph wires, accidental damage from vermin traps, snapping by sheep dogs, drowning in sheep-drains or moss-cuttings, etc., and wounding by shot. And of these no one can doubt that the " pricking " of birds due to bad shooting is the most frequent cause of damage. The following examples illustrate a number of these points : (No. 301.) A hen Grouse whose wing had been cut off clean at the shoulder, presumably by collision with a wire fence, not only survived collision to be shot the following season under suspicion of being a sick Wlth wire- bird, but actually succeeded in rearing a brood of five healthy young Grouse. Another instance of precisely similar nature is recorded elsewhere, in which the bird, a hen Grouse, had successfully raised a brood of healthy chicks notwithstanding the loss of a wing. In the first of these cases the wing was cut off so close to the body that no vestige of a stump was left. The cicatrix in the skin was adherent to the tissues about the rounded end of the broken humerus, of which only the head and neck were left. There was every appearance that the wound had healed well and quickly, probably some four or five weeks before the bird was shot, and soon after the nesting time. In feather and in condition the bird was not appreciably the worse for her mishap. The scapula, which had been broken in two pieces at the time of the accident, had made a strong though irregular union (see Fig. 1). For purposes of comparison a drawing is given of the bones of the undamaged (right) side of the same bird (see Fig. 2). The sternum or breastbone is another bony part also liable to injury, but sometimes without immediately fatal results ; in such cases damage is Fracture of most probably caused by collision with wire fencing. (No. 1672.) A hen Grouse was "picked up alive" on a Berwickshire moor in August. She weighed only 14|- ounces, and was very thin and in very poor feather ; but upon dissection it was found that, perhaps a month or two before, she had broken her breastbone right across by collision with something probably a wire fence. The smaller posterior portion had been displaced 154 THE GROUSE IN HEALTH AND IN DISEASE forwards and upwards, riding upon the larger portion, and there becoming fixed firmly by osseous union, but with a considerable amount of displacement Fractured end oF left humerus United fraerure oF Seapula Claviele Fig. 1., No. 301. A permanently fractured left humerus and a fractured and reunited left shoulder blade. and shortening (see Fig. 6). This accident must have completely disabled the bird for six weeks or a month, rendering her quite unable to fly. Yet Fig. 2, No. 301. The same bones uninjured from the right side of the same bird. she had lived, and the broken bone had united. The only apparent disability remaining was the infestment with parasites, Hymenolepis, Davainea and Trichostrongylus having all established themselves in excessive numbers in CAUSES OF MOKTALITY IN THE RED GROUSE 155 the various portions of the gut. Thus Strongylosis would have eventually killed the bird, but only indirectly and as an after result of the injury, which in itself was cured. (No. 1626.) A young Grouse chick, ll|- ounces, very plump and well feathered, was found dead in Argyllshire, August- 1908, and was forwarded for examination. There was no sign of disease, the bird was in excellent condition, and death had resulted from collision, probably with wire fencing, which had broken the breastbone right across. There was hardly any external sign of damage in this case ; but on removing the skin the bruising and bleeding which overlay the more serious damage beneath at once indicated the cause of death. It is easy to distinguish between damage before and after death, when it is remembered that the circulation is active in the former case and in- active in the latter. Any violence done before death is accompanied by bruising and bleeding. Damage done after death may be accompanied by post-mortem staining due to the leakage of bloody serum ; but will never show blood-clots lying under the skin or amongst the muscle - sheets or other organs. (No. 1824.) A hen Grouse, of 20 ounces, was "found dead, but quite warm, about a mile from the nearest part of the moor, and at a place Fracture of down to which Grouse never go unless when driven off the moor by storm, which very rarely occurs." This was in Cumberland in March 1909. The bird was quite healthy, in good condition, well feathered, and of a fair weight, and having been found dead with feet and legs well feathered, was just the kind of bird to be classed as a case of " the acute form of ' Grouse Disease ' which kills off birds in splendid condition before they have time to waste." But there was some blood in the mouth, and when this clue was followed up by further dissection the root of both lungs was found to have been torn to pieces by splinters of bone from the fracture of two or three vertebrae. There was a fair number of Trichostrongylus in the caeca, but no sign of disease and no tapeworms. (No. 1762.) A cock Grouse of 26 ounces was forwarded from Scotland with the correspondence quoted below. The case affords an excellent internal example of the evidence upon which the idea of an acute and very mjl " rapidly fatal form of " Grouse Disease " has been founded. 156 THE GROUSE IN HEALTH AND IN DISEASE The gamekeeper writes as follows : " I am herewith sending you a Grouse cock which, I think, must have ' gapes ' or something. His neck is very much swollen. This is the third bird of the kind I have seen during the season. We are now seeing diseased Grouse, at least birds having all the appearance of such. In fact, taking all over I never saw worse feathered birds than those we get here. They are especially poorly feathered on the legs." This was written at the end of September when the birds were in full moult. This particular bird had still the old claws on, and two primaries of each wing to shed ; and the feet, though apparently unfeathered, were on closer inspection just beginning an excellent growth of young feathers. One of its eyes was damaged. Attached to the bird was a note saying that it was a diseased Grouse, notwithstanding that it was making a healthy moult for the winter, and weighed 26 ounces. On dissection the swelling of the neck was found to be due to a mass of loose blood-clot ; the thorax also was full of blood-clot, and the bruising and tearing of the blood-vessels about the root of the neck left no doubt that the bird had met with an accident. There were no tapeworms in the bird at all, and no sign of disease of any sort. And though the caeca contained a good many Trichostrongylus, there was no redness, and the mucosa was quite healthy. (No 1841.) A cock Grouse, 18 ounces, found dead on arable land. April 1909, Perthshire. Two or three others had been found there lately, but in this one, which was sent for examination, there was such profuse bruising and so much effusion of blood about the neck and throat that there was no doubt that the cause of death was accidental. Trichostrongylus, however, was very abundant in the cseca, though there was no redness of the villi ; Davainea was present in large numbers. (No. 1838.) A cock Grouse of 20 ounces was forwarded from Haddingtoushire in April 1909, with two others, definitely showing signs of advanced Strongylosis. This bird, however, had the lungs torn before death by pieces of broken rib, and there was blood in the mouth and trachea. In the absence of any note to the contrary this damage could be accounted for by the bird having been injured by a dog when picked up alive. But, as the bird was found dead in this condition, the damage probably occurred by collision with a fence or some accident of a similar kind. (No. 1397.) A hen Grouse of 26 ounces found dead and in excellent condition, CAUSES OF MORTALITY IN THE RED GROUSE 157 on May 5th, 1908, was brought for examination as a case of the acute form of " Grouse Disease," by a keeper whose birds were actually at the time dying in large numbers from Strongylosis. But this bird was found upon dissection to have a rent in the abdomen, and a wound from some wire or fence, which had led to extensive internal bleeding. It was undoubtedly a case of accident, though the bird was fully infested with Trichostrongylus, and there was a considerable amount of villous reddening in the caeca. Had the haemorrhage escaped notice, or had the bird been killed by some less obvious accident, it would have taken its place in the list of evidence which supports the belief in the acute and very viru- lent form of " Grouse Disease " which kills birds before they have time to waste. (No. 1296.) A cock Grouse of 21 ounces was "watched for ten days" in March 1908. During that time he was flushed regularly every day by the gamekeeper at the same place. But during the last few days he wound could not be flushed "without the help of a dog as he was becoming barbed every day the weaker " ; so he was shot, and forwarded as a case of " Grouse Disease." This he was, but only to a very slight extent. The real reason why he objected to being flushed regularly every day was because he had retired to a certain retreat to be away from other birds and remain quiet while a wire-fence wound healed. It was found that the wire had torn through the skin of his breast, and had rent the pectoral muscles, which are the muscles of flight. Had he been left alone he would have recovered in a few weeks, and would have rejoined the healthy birds on the higher ground as soon as he was fit to hold his own. This retirement of a sick or damaged Grouse to a place where he can recruit his health in solitude is in accordance with the habit of almost every animal that lives. (No. 1604.) A cock Grouse of I7f ounces was found dying in Yorkshire in July 1908 with a bad rent in the flesh of the breast, bleeding freely. It was to some extent also suffering from Strongylosis. Two cases of fractured sternum have occurred in Blackgame, forwarded for examination. No. 1234 represents a recent fracture of the sternum in a Blackcock. No. 1232 (see Fig. 3) represents almost exactly the same damage re- united, owing to the fact that the Greyhen, in which it occurred, did not die until some months after the accident. The exact method of overriding and union of the broken bone in this example is shown in Figs. 4 and 5 158 THE GROUSE IN HEALTH AND IN DISEASE which give a view of the breastbone from each side. Both cases occurred in a Fracture of very curious series of six deaths in Blackgame which were forwarded sternum in . Biackgame. for examination as cases of " Grouse Disease," all coming from the same locality. Fig. 3, No. 1232. The breastbone of a Greyhen fractured and reunited. The facts were as follows : (No. 1.) A Blackcock, October 16th, 1907: weighing 45 ounces: Remarkable ^ ' . . series of was lound dying ; in excellent condition. Had been feeding on corn. (No. 2.) A Greyhen, October 26th, 1907 ; found dying, thin, in poor condition, dirty beneath, and much bedraggled ; had evidently been squatting for a long time on the ground, unable to fly. This bird was forwarded by train for examination, and on arrival was still living. She was kept alive, feeding freely on grapes, until November 2nd, when she was killed with chloroform, as there appeared to be some internal damage with a complete absence of any sign of disease. On post-mortem examination the breastbone (Fig. 3) was found to have been broken right across near the abdominal end ; but it had since become firmly CAUSES OF MORTALITY IN THE RED GROUSE 159 united again with a little displacement due to overriding of the hinder fragment (see Fig. 6). Clearly this bird was unable to fly because the wings from long disuse had become weak, and adhesions about the pectoral muscles probably made the attempt to use them painful. The joints of the legs too were stiff and difficult to straighten, the result of long squatting on the ground amongst wet under- growth. She must have led a sedentary existence for some time, and would probably have died without regaining the power of flight. There can be no Fig. 4, No. 1232. View of the right side of Fig. 3. Fig. 5, No. 1232. View of the left side of Fig. 3. doubt that the cause was collision, probably with a wire fence. The organs showed no sign of disease. (No. 3.) A Greyhen, weighing 34 ounces, was found dead in good condition ; had been feeding on corn. Examination showed that an old wound had produced extensive bleeding in the abdomen, but so long previously that the clot was semi-organised and formed a series of concentric blood-cysts. A more recent damage had caused extensive bleeding around the base of heart and into the lungs, and this had killed the bird; but not until several hours had elapsed since the accident, which almost certainly resulted from collision with a fence. There was no sign of disease. (No. 4.) A Blackcock, weighing 41 ounces, was found dead on November 1st, partly picked by crows or mice, but in fair condition. It had been feeding on 160 THE GROUSE IN HEALTH AND IN DISEASE hawthorn berries. This bird had a deep wound in the breast, from an accident which had broken the lower end of the sternum. The damage was undoubtedly the result of collision with a fence, or something of the kind. It was exactly comparable to that in the Greyhen, No. 2, but more severe, so that the bird died shortly after the accident. No sign of disease was discovered. (No. 5.) A Blackcock, weighing 39 ounces, was found dead in good condition on November 4th. No food in any part of the gut. This bird had its back broken, and the bone splinters had torn the lungs and the smaller air-passages, so that they gradually filled with blood. The hinder part of the bird's body and its legs must have been paralysed, so that it could not search for food, .Fibrous Union. Fig. 6. Showing method of union of broken breastbone. and the drowning of the bird in its own blood took so long to kill it that all the food eaten before the accident was digested, and the remains passed. The whole body was full of venous blood, showing that twelve or twenty-four hours may have elapsed between the accident and the bird's death, which was due again almost certainly to collision with a fence. Once more there was no sign of disease. (No. 6.) A Greyhen, weighing 31 ounces, was found dead on November 4th in good condition ; again the back was broken, but this time lower down at the level of the last rib instead of at the fifth rib as in No. 5. The left lung was compressed and rendered absolutely useless by a large blood-clot which had collected in the thorax owing to internal damage caused by the splintered bone. This bird had evidently lived for some hours after the accident, and had CAUSES OF MORTALITY IN THE RED GROUSE 161 previously been feeding on corn. There was no sign of disease, and every reason to suspect collision with a fence as the cause of the accident. Obviously this series of deaths was not due to an epidemic of disease, though it is difficult to understand why so many birds should have collided with fences in the same locality, where no new wires or other obstructions had been recently erected. The gamekeeper's view at first was that they all had disease, and out- ward appearances to some extent supported him. Later on, however, the Black- game began to leave the valley where they had been feeding on corn, and where the accidents occurred, and once more took to the moors. The keeper reported that the Blackgame on the moors were quite healthy, and continued : "I have been among Blackgame and Grouse for over forty years, and I never saw Black- game affected the same way. If eating green oats is killing them, they have eaten them for over forty years and were not a whit the worse. I have known Blackgame eat oats from September to December, and not a single bird die from it. What puzzles me is why they are not dying in the next valley (3 miles off). When the Blackgame light on the ground they tumble on their heads. If there is a fence hard by they sometimes fly into it. I have seen many birds (recently) showing the same symptoms." All this suggests some form of intoxication, and it is just possible that the sodden and half-rotten grain eaten by the birds might produce sufficient alcohol by fermenting in the warmer process of digestion, to act upon them in this way. There is, of course, also the possibility that grain soaked in spirit had been purposely put down, but in this case it was improbable. It was certain, at any rate, that the epidemic was an epidemic of accidents and not of disease, however suggestive appearances may have been to the contrary. (No. 1627.) A cock Grouse of 21 ounces was caught and killed, July 1908, in Argyllshire. There was very great dilatation of the crop, which was filled with an old blood-clot and with heather, the crop contents had been Damage to there for a long while, and had become dry and mildewed. There were bTrW two or three cicatrised wounds through the skin and crop ; but these wire ' were all closed except one, which remained open and suppurating. The passage to the oesophagus downwards was free, and the bird might possibly have recovered in time. The crop was adherent everywhere to the subcutaneous tissues, and so to the skin. And there were numerous enlarged blood-vessels wandering both over the crop wall and also in the adhesions as the result of VOL. I. L 162 THE GROUSE IN HEALTH AND IN DISEASE the diffuse inflammation. It is extraordinary that the bird should so well have maintained its weight 21 ounces; Davainea was absent, Hymenolepis and Trichostrongylus were both present, but with no redness in any part of the gut. No. 684 is an example of recovery from a fracture of one of the wing-bones in a cock Grouse. The radius in this case had been broken in two at the junction tne m iddle and lower thirds, probably from a shot wound. The mus t have lived for at least a month or six weeks during the wound. winter without flying, but made a perfectly sound union notwith- standing, and survived to be shot dead on the wing in April as a healthy bird killed for purposes of crop analysis (see Fig. 7). Fracture of r < FIG. 7, No. 684. FIG. 8, No. 287. Broken and re-united wing-bones. No. 539 is again an instance of the radius being broken in two pieces at about its centre, probably by shot. In this case there was also some evidence of periostitis in the ulna at the same level. The union was in- complete when the bird was killed ; but, though some movement was possible between the broken ends, the formation of callus and new bone had made a considerable advance towards effecting a firm union. No. 287 presented a firmly united fracture of the radius which had been broken in two about the centre. There was no evidence of damage to the ulna. A shortening of 2 mm. (from 50 mm. in the sound bone to 48 mm. in the CAUSES OF MORTALITY IN THE RED GROUSE 163 damaged one), occurred in the united radius, and union was effected irregularly with a large boss of new bone (see Fig. 8). This bird was an undersized hen, killed as a "piner" on August 15th, 1906, and suspected of disease. She was shot on the wing, but was in very poor condition and badly infested by Davainea, Hymenolepis, and Trichostrongylus within, and by innumerable bird- lice and other parasites without. Nos. 434, 984, 1250 (see Figs. 9, 10, 11), all resemble one another in. Excessive thlekening or Fibula ImpaefeA Jftot- FIG. 9, No. 434. FIG. 11, No. 1250. FIG. 10, No. 894. Broken and re-united leg-bones. representing united fractures of the upper third of the tibia and fibula. In each case the fracture was comminuted. The shortening in one leg is from Damage to 83 mm. to 76 mm. The union in each was effected by an irregular l ^j'^ es and immovable mass of bony matter thrown out to include the fibula wounds - which is also greatly thickened. No. 434 was a cock bird which lived to be shot on January 7th, 1907, weigh- ing 20 ounces. The fractured end of the bone had been rendered smooth by absorption, and the deformity caused by overriding of the lower fragment 164 THE GROUSE IN HEALTH AND IN DISEASE had been partly obliterated. In No. 894 the upper fragment was united to the lower at an angle of 30 degrees. No. 1250 was also a cock, found dead in November 1907, having succumbed to Strongylosis. The shot which caused the damage can be seen to the left impacted in the bony mass. No. 1304 was a cock Grouse of 18 ounces, caught alive in poor condition, but in fairly good feather. It had evidently met with an accident. There appeared to have been a shot wound in the back, but the chief damage was in the leg, which was dislocated at the tibio-metatarsal joint, and one central toe Right femur from two points of view Normal left femur. Femur with bony growth. I 1 ., ,11 r FIG. 12, No. 696. FIG. 13, No. 696. FIG. 14, No. 696. FIG. 15, No. 998. Broken and re-united thigh bones. was also damaged. These injuries may have been secondary to the shot wound, and may have resulted from a heavy fall ; but the bird had survived, and would have recovered with some deformity. It was, however, a rather advanced case of Strongylosis, and badly infested with tapeworms also, both Davainea and Hymenolepis. Fracture of Two cases f damage to the femur may be mentioned : No. 696, a united fracture with shortening from 55 mm. to 43 mm. owing to the excessive displacement of the lower portion of bone. The upper fragment forms an angle of 45 degrees with the lower (see Figs. 12, 13). CAUSES OF MORTALITY IN THE RED GROUSE 165 The bird was a hen found dying from Strongylosis in April, but the fracture must have taken place at least six weeks before. From the complete union effected the bird must have been healthy at the time, but the accident may have been the starting-point of sickness, which resulted eventually in its death. Fig. 14 shows the undamaged femur of the same bird. No. 998 shows a bony outgrowth of the femur due to periostitis resulting probably from some violence which was insufficient to break the bone (see Fig. 15). No. 1757 was an adult cock Grouse of 16 ounces only, found in Nairnshire in September 1909, sick and unable to fly. It was a bad case of Stron- internal gylosis ; but the original cause of its sickness was a number of lead wounds, pellets which had some time previously passed through the pectoral muscles, the sternum, and the liver. No. 1739 was an adult cock Grouse of 18 ounces, in good feather, but found in Yorkshire on September 5th, 1908, sick and unable to fly. The bird was suffering from Strongylosis ; but there were also healed scars of shot-pellet marks. The lungs were somewhat stained post-mortem, but one of them was thick and solid. It was in part a dark, rich, reddish black all through, and in part normal pink. A line of adhesions joined up the second and third lung-lobes, and there were cicatricial puckerings showing where a shot had passed through. The solidification was due to old bleeding. A shot had also recently passed through the neck, traversing the muscles, and tearing a small hole in the trachea, which had remained unhealed. There was bloody fluid in the mouth and trachea. The skin wound, however, had nearly mended, but bits of feather were found in the tissues of the neck, and the scar outside was matted up with broken feathers. The skin wound made by the shot which passed between the ribs and entered the lung had completely healed, and its position only was shown under the skin by a small blood clot which persisted. This bird must have survived its most recent wounds for a week or two at the least. No. 1923 was a cock Grouse of 20 ounces, which was sent for examination from Perthshire in very good condition. The following information was sent with the bird : " I enclose a Grouse which I picked up to-day. I put up a pack of Grouse. This one rose a little after the others, and after flying about 200 yards dashed to the ground, and when I got up to it it was quite dead and blood flowing from its mouth." Examination outside before opening revealed the fact that the bird had been 166 THE GROUSE IN HEALTH AND IN DISEASE pricked by shot. One of the quill feathers was cut through, evidently by a pellet, and there were marks of shot in other quills. Blood was flowing from the mouth, and an examination of the lungs showed that one of them had been torn by shot so that many of the air-passages were full of blood. But the blood liberated by the original wound had clotted in the lung and saved the bird from immediate death. Had the bird been allowed to rest until this lung and its clot had healed and become firmly cicatrised it would perhaps have recovered. Instead, however, it was flushed and forced to take flight. This broke down the freshly formed clot, and the bird died of secondary haemorrhage. There was in addition to this a very large clot round the liver, showing that a pellet had entered this organ also. This case is a very good example of what has certainly been described in former years as the sudden death of birds from acute disease, which strikes them down in the pride of health in full flight and excellent condition. It is also a very remarkable case of long survival after serious damage caused by shot wounds. No. 1260 was an adult cock Grouse of 19 ounces, found dead on January 3rd, 1908, in Argyllshire. This bird had been badly sprinkled with shot some time before its death at least a couple of months, judging by appearances. That it should have survived at all is extraordinary. Three shot pellets were found lodged in the tissues of the neck ; two ribs had been broken on each side, and had firmly united again. There were small caseous masses in the lung, the remains of small localised abscesses which had been caused by the passage of the shot. The pleura were fastened to the ribs by traumatic adhesions ; and as the result apparently of some obstruction or damage to the usual set of veins there was a great enlargement of what are generally quite insignificant veins in the wall of the proventriculus. This swelling, however, is purely vascular, and a different thing altogether to the swelling in the two cases just described. It has in this respect some similarity to the case which follows, a case in which the increased vascularity of the proventriculus also resulted from damage to the thoracic viscera. No. 1279 was a cock Grouse of 23 ounces, found dead on February 17th, 1908, in Inverness-shire. It was in excellent plumage and condition, and although an abundance of Strongyles was to be found in the caeca there was no redness and no engorgement of the villi. The cause of death was apparently collision in flight, and the chief damage CAUSES OF MORTALITY IN THE RED GROUSE 167 was that suffered by the heart, which was much enlarged and swollen out to twice its normal size by a great extravasation of blood in the muscular tissue of the walls, both of the auricles and ventricles. The veins running in the wall of the proventriculus were much engorged. The lungs were unhurt, and otherwise the bird was perfectly normal. No. 1899 was a hen Grouse of about 17 ounces, found on July 23rd, 1909, in Sutherlandshire, sick and unable to fly. It was in very poor condition, and heavily worm-infested. But the chief cause of distress was a very large tumour Tumours caused by an aneurismal-like rupture of the vessels in the inner walls of y U s s j^ t the gizzard. The cavity of the gizzard was enormous, and the organ wound - occupied nearly the whole of the abdominal cavity, causing complete compression of most of the intestines intensified by the formation of adhesions due to peritonitis and the stretching of the normal mesenteries over the tumour. The tendinous and tougher portion of the gizzard had retained its normal size and shape, but the fleshy part had become greatly distended. The tough lining membrane was the part which had given way. No. 1177 is probably a case of a dermoid cyst situated in the neck, though the cyst simulates the occasional result of a shot wound in which small fragments of feather are enclosed in a caseous mass in the connective tissue between the skin and the crop. The crop in this case was not damaged. Scraps of feather formed the nucleus of two tumours 35 mm. and 15 mm. in diameter respectively. The sebaceous matter, of a golden yellow colour, was in concentric layers, enclosed in a thick fibrous envelope with innumerable blood-vessels covering the outer surface, and supplying the cyst wall with blood. No. 1159, a hard fibroid tumour 1^ inches (45 mm.) in diameter, pro- truding from the foreneck of this bird. The nucleus again was a fragment of feather, and this occupied a small abscess cavity in the tumour with a sinus leading to the outside of the skin. The tumour was covered by bare, rough, and rather thickened skin, devoid of feathers, and resulted probably from a shot wound. There was no connection with the crop. Various accidents may happen to the foot and metatarsus of the Grouse, ranging from complete loss of the foot at the tibio-metatarsal joint D amage to as in No 437, to the loss of toes at the metatarso-phalangeal joints, feet- or at the various inter-phalangeal joints as in No. 970. Steel vermin traps will perhaps account for some of these cases, but in No. 970 the appearance of the stumps of toes on both feet, to a different 168 THE GROUSE IN HEALTH AND IN DISEASE extent on each foot, suggests frost-bite as the cause ; or at any rate some form of gangrene rather than steel traps. A likely explanation is the strangulation of toes, sometimes even of feet, in infancy by the tightening of strands of sheep's wool accidentally wound round them. This is a common accident with Lapwings. An instance of the death of Grouse in a vermin trap may be recorded, in which two healthy cocks fighting in the spring accidentally came together into a " Samson " trap, and were simultaneously killed. No. 1606, a cock Grouse of 18^- ounces, was found dead on July 13th, 1908. There was a very little Calluna heather and Blaeberry leaf and stem in the Damage to cr P- The bird had probably found difficulty in obtaining sufficient food for the lower bill was split and curved, forming an unhandy instrument for plucking heather. The death by starvation, however, had been hastened by Helminthiasis. Davainea was abundant ; Hymenolepis filled the duodenum, which was purplish red, very congested, with engorged villi within, and engorged venules without ; while the cseca were excessively congested within and without, and Trichostrongylus was present in great numbers. This bird would very probably have recovered during the summer but for the additional handicap of its damaged bill. It had survived the two months of highest mortality, April and May. Many interesting cases have also been recorded of recovery from flesh wounds either by shot, or by barbed wire, and the following have come under the notice of the Inquiry : No. 1242 represented a long standing leakage of the crop, due to a wound through the skin and crop- wall. Owing to constant use of the crop, and to Damage to tne alternate distension and contraction of the overlying skin, the or P- adhesions between the edges of the skin and crop-wall had become permanent before there was any chance of the openings in either being closed. Bits of heather pressed constantly between the lips of the wound had prevented healing, and had defeated the efforts made by the crop to pass all the food into the gizzard. The bird had therefore to eat more than the normal amount to make good a chronic wastage, and this accounts for the very abnormal dis- tention of the crop which often characterises cases of the kind. - No. 1627 is another case of the same nature. Either or both of these last two cases may have resulted from shot wounds, CAUSES OF MORTALITY IN THE RED GROUSE 169 or from rents made by barbed wire. The latter is probably the cause in the majority of cases. It is fairly common to find shot pellets loose among the contents of the crop or in the gizzard. They have sometimes been lodged there when the bird was killed, but have more commonly been picked up and Shot fre . swallowed as grit, or out of simple curiosity. In one case a shot pellet f^und m was actually encysted in the thin wall of the crop. It would have found its way eventually into the crop without any damage ; but it is at least curious that a pellet having entered the bird with sufficient impetus to get through the skin and half way through the wall of the crop should not have gone right through into the contents. No. 1150 is a similar case resulting from a shot wound; the pellet had entered the body of the bird, and having perforated two portions of the gut had then lodged in the gizzard. Localised peritonitis had followed, causing abundant adhesions, and a short cut had been established between the gizzard and the main intestine as well as another from the upper portion of the main intestine to a lower portion of the same. The danger to young chicks in sheep drains and in moss cuttings for "peats," or for general surface draining, has already been mentioned. It is greatest during a " spate " after a spell of dry, hot weather in June or July, when young broods have been led by their parents to take shelter sheep from the sun in dry drains cut with steep sides. The sudden filling of these drains is responsible for the loss of many chicks before they find a place to scramble up into safety. This danger is well recognised, and the best method of avoiding it is dealt with in another chapter. 1 Accidental poisoning is a rare cause of death in Grouse. A few cases have been brought before the Committee as cases of " Grouse Disease." It is not easy to guess how poisoning occurs, for poison used in killing vermin Accidental is administered mainly in eggs, and in the carcasses of fur-bearing pois animals, neither of which are likely to be tampered with by Grouse. Poisonous sheep dip has been blamed in some cases ; but it is difficult to believe that it can be more than the rarest cause of accident. The theory that many Grouse are poisoned by lead pellets, whether swallowed as such, or in solution as carbonate of lead in drinking water has been ingeniously upheld by an elaborate calculation of the amount of shot scattered over a moor 1 Vidt chap. ii. p. 15. 170 THE GROUSE IN HEALTH AND IN DISEASE in a shooting season ; but though the crops and gizzards of Grouse do occasionally contain a lead pellet or two, they are sufficiently uncommon to be a matter of curiosity to the finder rather than a cause of sickness to the birds. 1 The following is an account of what was supposed to be accidental poisoning of Grouse by sulphate of Barium. It is given by Macpherson in the " Fauna of Lakeland. " ; Quoting John Borrow as writing from Alston in 1837, he says : " In consequence of the Grouse in some parts of this neighbourhood having been unable to procure sand (owing to the depth of snow), they have picked up particles of the sulphate of Barites, which appears to have been the cause of a very great mortality among them. A person whom I can depend on assures me he saw not less than forty brace dead upon the moors a few days since." One may, I think, legitimately wonder whether this mortality was not due rather to a grit-starvation, accompanying and augmenting the evils of food- starvation, which is always present to some extent with deep snow. The Rev. E. A. Woodruffe Peacock gives cathartic flax as a cause of death by violent purging to young Pheasants ; but no case of poisoning in Grouse can be attributed to the consumption of any plants found growing upon a moor. Several cases of abscesses and septic poison of the leg, which resembled Abscesses " bumblefoot " and "whitlow," were sent up for examination during and septic poison. 1908 (see Plate XXXII.). No. 1681 was a cock Grouse of the year, shot purposely on August 25th, 1908, on account of the condition of its body and feet. The foot of another Damage Grouse was affected in the same way though to a less degree. This and leg. bird weighed 15^ ounces, and its condition was fair. Both feet were much swollen with collections of caseous pus. The figures shown on Plate XXXII. were drawn from the bird when quite recently dead. It was killed " on an exceptionally dry juniper hill " in Inverness-shire. There were no abnormalities in any other part of the bird, except the usual infestment of Trichostrongylus ; but the organs were all apparently healthy. No. 1744 was an adult cock Grouse shot in September, in Perthshire, weighing 19^ ounces, and somewhat thin. It exhibited the usual infestment with Hymenolepis, Davainea, and Trichostrongylus, but was otherwise healthy except for a swelling of one of the toe joints, very similar to the case just described (No. 1681), but not symmetrical. 1 Vide Macdonald, "Grouse Disease," p. 160. 2 Vide Reverend H. A. Macpherson, " A Vertebrate Fauna of Lakeland," p. 323. Edinburgh : D. Douglas, 1892. PLATE XXXII. 40 o O -P O Ld CO D O tr O O O U. UJ _l 03 2 D CQ o o E.Wilsan ,Cs.ni Opposite p. 17').] CAUSES OF MORTALITY IN THE RED GROUSE 171 No. 1675 was a young bird of the year, shot in September, on the same moor in Inverness-shire which produced No. 1681, and another similar specimen which was not forwarded. All came from a very dry, healthy, juniper-covered valley, and all had appearances much resembling the disease known to poultry farmers as "bumblefoot." No. 1918 was an old heu Grouse killed in Yorkshire, which weighed only 13f ounces, and was exceedingly thin. This bird had a swollen knee of the same character as the above, and there was some evidence that it was an old standing trouble, for the claws on the foot of the damaged limb were of an abnormal length, whereas those on the foot of the sound leg were broken and worn to stumps by the extra amount of wear and tear. The feathers of the left undamaged leg were similarly much worn, whereas those on the damaged leg were in good condition. The bird was suffering from Strongylosis, the caeca being very much congested and full of Trichostrongylus, and the villi very red. There was an old blood-clot over the liver, which may have resulted from a stray lead pellet, and the swelling of the knee joint in all probability should be attributed to damage by another pellet which may have struck the bird at the same time. In poultry farming "bumblefoot" is tlte name given to Bumble- any form of abscess in the foot, and as the abnormal structure of the foot- Dorking's foot with its extra toe made this breed particularly liable to have a suppurating corn or other accident of , this nature, it was considered at one time to be almost peculiar to that breed. It is evident, however, that in the Grouse which have been considered above, and in the poultry affected with "bumblefoot," we have generally the result of localised suppuration from septic infection, following upon some small and unnoticed wound or damage such as a scratch or bruise. A " whitlow " is exactly comparable to this affection in the toes, and a whitlow may be a septic affection of the superficial or deeper tissues, and if of the latter, the infection may spread to tendon sheaths, or even into the joints themselves, or upwards between the muscles. In the Grouse above mentioned the suppuration is more or less localised, and the pus, having no free exit, has become caseous in the lapse of time, hence the firmness of the swellings. 172 THE GROUSE IN HEALTH AND IN DISEASE B. Causes of Death and Damage resulting from Natural Conditions. Nearly all the causes of death and damage due to purely natural conditions have from time to time been so well described that it will here suffice merely to recapitulate them. 1 1. Climatic extremes are well known and well recognised. They may Climatic occur from the time the eggs are laid to the end of the bird's life. extremes. ^ everv a g 6j j n ev ery season, and every year, the welfare of the bird is threatened by excess in one direction or another. Excessive heat and its usual accompaniment, water famine, are both somewhat Heat and uncommon at the time of year when they would be most dangerous drought. to Q rouse life. They are referred to in chapter ii. 2 The following abstracts sum up the harm done by wet and cold. Macdonald in "Grouse Disease" has no doubt about the matter when he writes that Wet and "Damp and cold never fail to produce diarrhoea, cramp, and disease"; and again, " Excessively cold or wet seasons are succeeded by great mortality among birds, and Grouse suffer more in wet than in dry seasons, how- ever cold this was strikingly demonstrated in the wet season of 1872-1873"; and again, " Cold wet causes bad hatching seasons." " So also Macpherson in the Fur and Feather Series says that young Grouse " do best in fairly dry seasons." 4 And for the bad effect of cold and wet on the food supply Macdonald, again, in " Grouse Disease," says : " We can also connect the disease with wet seasons. The heather does not quite ripen, particularly the small tops on which Grouse chiefly feed." 6 There seems, in fact, to be a consensus of opinion amongst those who have had the best opportunities for judging, that the hatching season can hardly be too dry so long as there are dewy nights. The chicks can supply their needs by drinking dew in the morning, and beyond this they find sufficient moisture in the insects and young succulent moss-capsules and heather shoots which form their staple diet, and which contain something like 60 to 80 per cent, of water. The sitting hens want water and must have it, and their bulky droppings may 1 In connection with the effect of weather conditions upon Grouse, much additional evidence has been collected by the Committee, and is summarised in Appendix G., vol. ii. In view of the information now made available for the first time, it may become necessary to reconsider some of the opinions of recognised authorities referred to in this chapter. ap. . 3 Macdonald, " Grouse Disease," pp. 24, 40. 4 Fur and Feather Series, " The Grous * Macdonald, " Grouse Disease," p. 40. CAUSES OF MORTALITY IN THE RED GROUSE 173 always be found on the edges of the burns and springs nearest to their nests. They are reported to suffer seriously in a drought. But when all is said, excessive heat and drought are far less to be feared in the British Isles than excessive wet and cold. Sunstroke, "staggers," and " splanders " in wild birds of any kind are extremely rare when compared with the results of an exces- sively wet hatching season, especially if it happens to be accompanied by cold. Too much wet is undoubtedly more harmful both to the sitting hens, to the eggs, and to the young birds when hatched, and for a month at least after hatching, than any other climatic extreme to which Grouse are subject. Excessive Excessive rainfall is said to account for the scarcity of Grouse on wet a great the moors of the west of Scotland and of the Western Isles, and to this John Colquhoun adds that " Grouse are never so plentiful on the west coast, from the wet springs addling so many of the eggs." And again, " Protect as strictly as possible, and kill every rapacious bird and beast on the ground, there never could be half as many Grouse reared in the west as in the north or centre Highlands ; and the reason is the humid climate prevents it." "Every sportsman knows that the Grouse in the north or centre Highlands of Scotland are immensely more numerous than in the watery west." The nesting season of 1906 was most typically a bad wet season everywhere, and in walking over some of the Scottish moors, south of Perth at any rate, nest after nest was found to be deserted with a full clutch of eggs in which the chicks had died just before the time of hatching. Second broods are in such cases no doubt produced, but if an early winter sets in, or if the autumn turns wet and cold, these late-hatched broods swell the ranks of the poorly- feathered, undersized birds which appear in spring as "piners," and broods and .. , , late birds. are liable to succumb eventually to disease of one sort or another. The question of the diminished value of second broods is fully discussed in another part of this Report. 3 In every way, except in checking the growth of the heather, hard frosts and heavy snow do less harm than excessive rains. A certain number of Effect of hens may be occasionally frozen to death upon their nests, as has been ^foo^ '' recorded by Stuart- Wortley (Fur and Feather Series). Eggs, too, su PP lv - may be " frosted " when late frosts are sufficiently severe, 4 or young Grouse 1 Colquhoun, "Moor and Loch," vol. i. pp. 194-198. 2 Ibid., p. 198. 3 Chap. xxi. pp. 469 et seq. * W. A. Adams, "Twenty-six years' Reminiscences' of Scotch Grouse Moors," p. 94. London: Horace Cox, 1889. 174 THE GEOUSE IN HEALTH AND IN DISEASE may be killed by late snowstorms, as in 1864 on Glenshea ; but such occur- rences are very rare. The power of resistance of the egg to frost is dealt with in another chapter. 1 Still, however little direct harm excessive cold may do to Grouse, the indirect harm is often very great, and there is no doubt that late frosts in the north of England and in the south of Scotland, catching the heather after the sap has begun to rise, often reduce the available supply of food. It may be well to review what has been written from time to time as "Frosted * * ne en?ec t that " frosted heather" is supposed to have upon the heather." G rouse . In Macdonald's "Grouse Disease" a Scottish forester is quoted as having stated that during a certain epidemic there was no " Grouse Disease " all along the sea coast where the heather does not suffer by frost, while 10 miles or so inland, beyond where the sea exercised its influence, there the " Grouse Disease " began. It is there stated that the dissection of Grouse that had died of the disease proved that their crops contained frost-bitten heather. 2 And, again, in a quotation from Colquhoun's paper, it is stated that in Perthshire, in 1852 and 1853, the heather was excellent, and in consequence there was no disease, while in 1854, 1855, and 1856 the heather was frosted without snow, and there was bad disease. Again in 1857 the heather was excellent, and there was no disease ; and so on. 3 Speedy, however, says : " Heather which has been killed by frost and entirely divested of its nutritive qualities is about the most unlikely thing for Grouse to feed upon." 4 He says, too, that after bad disease there are more survivors on the high exposed heather-frosted parts of the moor than on the lower sheltered localities, and that "'Grouse Disease' has not been peculiar to those seasons when the heather was most generally frost - bitten, or when it had not been covered and protected by snow. . . . Some of the most fatal visitations have been preceded by winters more remarkable for mildness than severity." The statements contained in the above quotations from Macdonald and Colquhoun are probably due to a misuse of the term " frosted heather," for there is a condition of heather which is not rightly called "frosted heather," and it will 1 Vide chap. ii. pp. 10-12, vol. ii. Appendix H. 2 Macdonald, " Grouse Disease," p. 40. 3 Ibid., p 122. 4 Tom Speedy, " Sport in the Highlands and Lowlands of Scotland," p. 202. Second Edition. Edinburgh and London : William Blackwood & Sons, 1886. CAUSES OF MORTALITY IN THE RED GROUSE 175 prevent misunderstanding if the meaning of the term is clearly defined. To begin with, young, fresh, green heather of the early summer may be caught by a late black frost which sweeps over the moor and literally " scorches " it red. This is a comparatively frequent occurrence in the north of England, and was well exemplified on a certain Yorkshire moor in the early summer of 1907. The countryside was green one week, and "as red as a fox" the next. Every leaf that was turned red by the freezing winds (there was no snow in the question) died, and eventually dropped off without recovering. But the plant was not killed ; it very soon put out fresh leaves from the lower stalks, and the moor in a few weeks was as green as ever. Still, the fact remains that the birds of that moor were suddenly reduced from a very abundant to a very limited supply of food, for in no case will a Grouse eat such useless stuff, nor has a Grouse's crop ever been found to contain this fox-red frosted heather. It is dead, and the birds know it, and forthwith proceed to look for something that is not dead. They will not eat it, and therefore any harm that accompanies its appearance is due, not to the presence of this useless refuse, but to the sudden reduction of the wholesome food supply. Such fox-red frosted heather must on no account be mistaken for the dark, red-brown, winter heather, which is secure from any ordinarily severe frost, and is merely the resting condition of the healthy living plant. The two are totally distinct in colour, the former being, as has been said, brick-red or fox-red, and the latter a deep brown, or dark, reddish brown, often associated in the leaves of the other side of the twig, with a deep or vivid winter green. Such heather is alive and healthy, and forms perfectly " Winter wholesome food for the Grouse ; it is, in fact, their staple winter food, heather" mi i i i /I'-i-i' not frosted. I he only point is that being somewhat dry and sapless (m which lies the whole reason of its immunity to frost), and lacking in food-value when compared with fresh, young, summer heather, about three or four times as much has to be eaten by the bird to get the same amount of nourishment. This dark, winter heather cannot be correctly called "frosted," since the change in it is merely due to a seasonal alteration in the chemical condition of the cell contents, while it remains in the healthy resting winter state. With certain modifications it may be stated generally with regard to the two forms of " frosted " heather that in the one case the heather is dead having been killed by even a moderate frost and that in the other it is living, and is proof against even a severe frost. The presence or absence of snow on the ground makes a great difference in 176 THE GROUSE IN HEALTH AND IN DISEASE time of frost. Snow acts as an efficient protection to the heather, and only the extra long twigs that protrude beyond the snow are affected by protection frost. Hard frost after snow trims the heather by cutting off and from frost. killing all the longer pieces, so that the leaves bleach whitish grey, and eventually drop off. This may happen even to straggling pieces of dark brown, winter heather if the frost is severe enough ; but it requires a very low temperature and a prolonged exposure to affect real winter heather to any great extent. There is no other condition of heather which can with any show of reason be called " frosted " ; and it may be urged that no heather should be so named except that which has been nipped and killed beyond all chance of recovery. To call the resting condition of winter heather " frosted" is as unreasonable as to call any evergreen shrub "frosted" because its winter leaves are darker in colour than those which it produces in early summer. Closely simulating the fox - red, frosted heather, however, is the heather damaged by a certain beetle known as Lochmcea suturalis. This pest Effect of _ " heather has long been recognised in Argyllshire, Ayrshire, and Dumbartonshire, D66tle. . and its ravages were described by Mr Grimshaw in 1898. * This subject is also dealt with in the present Report.* Before leaving the climatic causes of death and damage to Grouse, something remains to be said about heavy snow. Its most obvious danger lies, of course, Heavy in starvation, since a heavy snowfall, unaccompanied by wind, and not follow&dby a thaw for many weeks, reduces the available food-supply to a minimum, and drives the Grouse to travel far and wide over cultivated lands, into gardens, town outskirts, and even to the seashore for a scanty living. It is recognised that one of the best ways to help Grouse under such circum- stances is to lay bare patches of heather by breaking through any hard crust that may have formed on the surface of the snow. This may be done either by rakes or harrows, and the spots chosen should be those where there is known to be the best supply of good feeding heather. As a rule there is sufficient wind with the snowfall to ensure that large tracts of ground remain uncovered on exposed ridges, and on the weather side of hill faces. When this is so, the Grouse collect on them ; but as these exposed tracts are always on the weather side, and almost always on the shoulder of a hill, it is usually the worst heather which is exposed. The lee side is probably buried deep in snow. 1 "Annals of Scottish Natural History," vol. vii. p. 27. 2 Chap. xix. pp. 414 et seq. CAUSES OF MORTALITY IN THE RED GROUSE 177 Attention has already been drawn to the benefit derived from sheep and deer in time of snow, owing to the surface of the snow being broken by their tracks. But although the heather may be exposed, and even though oats and corn may have been put down in abundance for the birds, the most important Need of step has otten not been taken to relieve the necessities oi starving grit in time Grouse. They must have grit, for without grit it is almost useless to put down corn. This was realised and put into practice in the snowstorm of 1881 ; but only by very few. Corn was put down here and there for the ravenous birds, and though some of it was eaten it was evidently not what they were most eager to obtain. On one moor, at any rate, men were then sent out with shovels, not merely to expose the heather, but to open up the "scrapes" along the road sides all over the moor, and thus to expose fresh grit. Every day new grit was laid open and rotten quartz and sandy rock were broken out, and each day a fresh supply was needed. Grit, therefore, was what the birds were really starving for, and it was the want of it that rendered them incapable of dealing with hard corn or winter heather. With good quartz grit they can deal with almost anything, even the very woody heather that appears above the snow ; without grit they will starve. Any one may assure himself of this by examimng the winter crop-contents of the white-winged Willow Grouse or "Rype" of Scandinavia. the bird which decorates our poultry shops as " Ptarmigan " in winter. It is quite wonderful to see how excellent is the condition of these birds, living as they do on hard wooden alder twigs and alder buds, woody dwarf willow twigs and old rank heather. Their crop contents are extraordinarily hard and woody and uninviting in appearance, and yet with good quartz grit it is all ground up and utilised. 1 Another cause of death to Grouse is the ravages of birds and beasts of P re 7' 2 Vermin. Deaths also occur amongst Red Grouse owing to the antagonism which exists between the male birds of Blackgame and Capercailzie, and those of the Red Grouse. The two former have been blamed for the disappear- Blackgame ance of Grouse from certain parts of the country. John Colquhoun, caper- speaking of the decrease of Grouse in some districts says: " This ca " zie - may in part be attributed to the advance of cultivation ; but I cannot help- 1 Vide also " Experiments on Effect of Grit Starvation," vol. ii. Appendix F 2 Vide chap. ix. pp. 443 et seq. VOL. I. M 178 THE GROUSE IN HEALTH AND IN DISEASE thinking the Blackgame have a good share in driving off the Grouse, as I know of one instance where the former were killed off, and the latter again returned to their old haunts. I believe it is also more than suspected that the Capercailzie, wherever they are introduced, have a great inclination to dispossess both." : The conditions have altered much since this was written. Large tracts of Blackgame country have been drained and put under cultivation ; and Capercailzie have in many places again become abundant after a temporary extinction. Planting has become much more general, and the presence of young larches often determines the movements of large numbers of Blackgame. Corn feeding is a habit which has become general amongst Grouse and Blackgame wherever the lie of the land permits, or the condition of a moor Corn feed- facilitates it. It is often mentioned as an accompaniment, or a cause, mg - or a forerunner, or a consequence, of " Grouse Disease." The opinion of gamekeepers on the subject is about equally divided ; some say that it does the birds more good than harm, and others say exactly the reverse. Some again say that it does them neither good nor harm, and others that it is a sure precursor of disease. Occasionally yet another suggestion is made which appears on the whole to meet a certain proportion of cases, namely, that in certain districts the weaklings alone are to be found upon the stooks and stubbles, or, in other words, that corn feeding is a consequence of sickness, not a cause. Generally speaking, in districts where large packs habitually come upon the stubbles, it is probably because they have insufficient food upon the moors. Grouse when feeding on the stooks are generally not only healthy but wild, until they have filled themselves with corn, when their habitual weariness often seems to leave them. This has long been recognised, and in Adam's " Reminiscences," for example, we find the statement that " Grouse, when they get on the plough are sometimes very stupid." ; A case in point occurs in the extraordinary series of deaths from collision in Blackgame which has been described above. 3 Something connected with the corn upon which the birds were feeding seems to have been the cause of their incapacity. Corn feeding then is customary with healthy Grouse on some moors much more than on others ; but the evidence seems to show that when sick birds appear on the cornfields they are there because they are sick not that they become sick as 1 John Colquhoun, " Moor and Loch," p. 202, note. 2 Adam, " Reminiscences," p. 25. 3 Vide pp. 158 et seq. CAUSES OF MORTALITY IN THE RED GROUSE 179 the effect of having been upon the corn. St John notes that on August 12th, 1847, during a severe epidemic of disease in Morayshire, Grouse were feeding in numbers on unfilled green oats in the small fields near the moor. This, he says, he had never seen before, though he was accustomed to see Grouse flocking to the stubbles in the autumn. 1 Sickly birds found feeding on the stooks were forwarded for examination in 1908, birds seriously diseased with Cobbold's Strongylosis, wasted piners that could hardly fly. These were probably sick birds that had been crowded out from the good feed on the moor by the healthier birds which live there in packs, and only occasionally make a raid upon the corn. Possibly the stubble fields may become dangerously infected ground if sick birds frequent them even in moderate numbers. They may con- Dangers of tammate with their droppings far more corn than they can eat, and corn feed- healthy birds may thus run a risk if they make their visits too frequently. It is perhaps in this way that the idea originated that overmuch corn-feeding is a precursor of disease. The following extracts bear out this view of the matter : Macdonald quotes as follows from a pamphlet written by Mr William Colquhoun of Ross-shire in 1858 : "The Grouse have fed a great deal on the stooks during the disease (1854-1856) ; and on the stubbles after the corn was stacked ; and also in spring on the sown corn. This year (1858) the Grouse did not come to the corn as in former years." (The disease had then quite disappeared.) 2 Again Colquhoun says that Grouse thrive in confinement when fed on corn ; but allows that their greed for corn increases in disease years. He thinks that possibly they are upset by eating damaged and unwholesome heather, and are driven to stook and stubble for a sufficiency of food. 8 Speedy, too, writes as follows : "An excessive consumption of corn by the Grouse species, particularly in wet seasons when the harvests are late, has been assigned as a cause of the ' Grouse Disease.' ' : But he goes on to say that hand-reared Grouse can live for several years in perfect health without seeing anything but corn ; and that whereas on the Dalnaspidal and Rannoch moors the birds were too far from cultivation ever to see corn, yet they suffered badly from disease in 1873. 1 Charles St John, " Natural History arid Sport in Moray," p. 202. Edinburgh : David Douglas, 1882. 2 Macdonald, " Grouse Disease," p. 123. William Colquhoun, " Remarks on the Decrease of Grouse and the Grouse Disease," p. 29. Edinburgh : Edmonston and Douglas, 1858. 3 Colquhoun's Pamphlet, p. 30. 4 Speedy, " Sport in the Highlands and Lowlands of Scotland," p. 200. 180 THE GROUSE IN HEALTH AND IN DISEASE As with theories based on the belief that Grouse feed on frost-bitten heather, so with those that are based on their feeding upon corn, very little actual evidence is brought forward from post-mortem examinations to show that they suffer any harm at all from the latter food, or that they ever under any cir- cumstances fill their crops with the former. In the examination of some score of birds whose crops or gizzards contained traces of corn, only one or two showed any evidence of damage that could be directly attributed to its presence. These cases are more fully discussed in another chapter. 1 Some of the birds were obviously piners that had been sick for a considerable time, and there is no doubt that their visit to the cornfields was to some extent involuntary for the reason that they found themselves unable to hold their own with the packs of healthier birds upon the moor. To some extent also no doubt it would be inevitable because from sheer weakness each flight would tend to bring them nearer to the lower cultivated ground. But this use of cultivated ground as a congregating area for sick birds depends largely upon its position with respect to the moor. If even a few habitations intervene, the Grouse, whether healthy or unhealthy, will hardly ever visit the corn, except under urgent pressure of starvation. Conditions very conducive to corn feeding exist in parts of southern Perth- shire, where the high ground runs in long and comparatively narrow ridges, while the valleys between the ranges of hills contain open areas of farmed arable land right in the very midst of the lower beats of the moors. For many reasons such low ground, whether farmed or not, must always be to some extent less healthy than the high ground, and the cornfields the least wholesome parts of all. First, because all the weakly birds on the moor tend to leave the high ground for the low, thus turning the stubble fields into concentration centres. Here, too, large packs of healthy birds making raids from the high ground not only themselves foul the lower ground with an excessive amount of loose droppings full of nematode eggs and unhatched larvae, scoured from them by the irritating corn husks, but also run a great risk of filling themselves with corn which has been fouled by the convalescent, sick, and more permanently diseased occupants, whose droppings are even more abundantly full of nematode eggs than are their own. This is no doubt the point to which Colquhoun refers when he says : " My opinion is that corn is very unwholesome food for Grouse. Let any person examine the 1 Vide chap. iv. pp. 81-82. CAUSES OF MORTALITY IN THE RED GROUSE 181 droppings of Grouse when fed on corn, and they will find them similar to tar, but rather browner in colour." Such droppings are not so abnormal as Colquhoun believed, coming as they do direct from the caeca ; but they are full of the ova of Trichostrongylus, and are thus a menace to the health of other birds frequenting the same feeding grounds. Low ground such as this in southern Perthshire must thus have a tendency to become thoroughly infested with the eggs and larvse of threadworms, as well probably as with the eggs and cyst-bearing hosts of the tapeworms. The higher ground on the other hand has a tendency to get rid of these eggs and larvae by natural drainage at the expense of the lower ground. Every spate must wash down millions of nematode larvae from the higher to the lower ground, where often there is little natural drainage, and the artificial drainage is inadequate. Turning now to the dangers and risks attendant upon the natural processes of production and moulting, we find that the exigencies of courtship, mating, and moulting in the male, of moulting, the laying of eggs, and the Risksof hatching out and rearing of a brood of chicks in the female, tw 0du " constitute the sequence of a taxation which bears heavily upon the processes. Grouse. It is worth while to look at them in detail to see to what extent each may fairly be burdened with responsibility. If an inquiry is made into the cock bird's life he will be found engaged in constant vigilance and warfare from the time of pairing, generally about the end of February or March, onwards for a month or two at least. The -, ,. ,. Warfare battles are more bloody and more disastrous to the weaklings than among is generally supposed, and many of the half-starved and parasite- infected cocks, the so-called cases of "disease" found dead along the burns, have really been killed in fighting. It is a fact, testified by more than one reliable gamekeeper, that two or more healthy cocks will sometimes set upon and kill a weakling before they settle their own dispute ; and of the urgency of their own dispute the following quotation by Macpherson in the Fur and Feather Series affords a good example. He quotes a Perthshire keeper, who " saw two male Grouse engaged in combat, so completely blinded by fury were the birds that they dashed against the wall of a stone building, one of them killing himself with the impetuosity of his flight." ; In the same work 1 Colquhoun's Pamphlet, pp. 29, 30. 2 Macpherson, Fur and Feather Series, " The Grouse " p. 32. 182 THE GROUSE IN HEALTH AND IN DISEASE Mr Stuart- Wortley writes : " In the pairing season the old warriors come down from the heights, fight with and vanquish the younger ones, and absorb the young hens." l Such efforts combine to bring to an end a very large proportion of cock birds which are more or less exhausted after the winter by poor feeding and the loss of strength due to the presence of intestinal parasites. Then follows the moult, an exhausting process under the best conditions, Moulting an< ^ one f r which nature generally makes provision by laying in a m the cock. s f; OC k O f subcutaneous fat. All this is consumed during the growth of the new feathers. But in the case of an ill-conditioned Grouse the moult commences with an insufficient supply of fat from which to draw for the growth of the new feathers. The result may be a complete failure to rise to the occasion ; or, if the failure be only partial the old feathers will be retained to some extent, and the new feathers will come slowly, poorly, and sparsely. Bare legs and a poor-looking mixture of old and faded feathers, with a more richly coloured new one here and there, produce a seedy, chequered-looking bird, and to this must be added an air of exhaustion and malaise. Occasionally in the male the summer change of plumage is not completed even by autumn, and feathers of three different plumages may then be found on a single individual. But as the season advances, and good food becomes more abundant, by degrees the moult is completed in a more or less satisfactory manner. The chief troubles are then over for the cock, and he gradually improves in condition to meet the ensuing winter. But now to consider the hen, whose lot is certainly less enviable than that of her mate. She also may have struggled through the winter, and while the Taxes to cocks fight over her is quickly putting on fat for an early moult. She henla makes an almost complete change of plumage before laying her eggs in April ; and in this she must consume a portion of her strength. She recuperates in sitting, but feeds only scantily the while. Then her troubles begin to be more pressing, especially if by any mishap she loses her eggs and has to lay and sit a second time. If, however, by the end of June she hatches off, she must still be constantly on the watch for danger to her chicks. In July she has to moult again. Little wonder that by August she is sometimes reduced to the con- dition of a " piner," or that, when the shooting season comes, she is discarded from the day's bag, to be submitted for examination under suspicion of " disease." It is the same story precisely as in the case of birds handicapped for life 1 Macpherson, Fur and Feather Series, "The Grouse," p. 147. CAUSES OF MORTALITY IN THE RED GROUSE 183 through having been hatched late in a second brood. In the one case the birds are full grown and healthy to begin with, but have been unable to stand the strain of breeding and moulting. In the other case they have never had a chance to become full grown. In either case the course of natural taxation is the same, the parasitic infestment is the same, and the final result to the bird is the same. The only thing which differs is the primary cause of weakness, and this may be one, or several, of a very considerable number that lie in wait for the life of the Red Grouse on every moor. Of accidents which may happen in the process of laying, there is one which is well known in captive birds, but must be rare in nature, namely, a shortage of lime rendering the eggs deficient in shell. Soft- Soft shelled eggs not only fail to stimulate the muscles of the oviduct, but she11 -" give them no purchase upon which to act. The consequence is that the egg is not expelled, but is broken in the duct, and is followed by other eggs until the bird dies either from exhaustion or from a rupture of the oviduct involving the peritoneum. Soft-shelled eggs in wild birds generally appear in a second clutch laid shortly after the loss of the first nestful. Gastro-uterine gestation must always be rare, but one well-marked case in a Grouse was sent up for examination. The egg, when shed by the ovary, failed to enter the open upper end of the Fallopian tube, and so passed into the body cavity. By causing irritation there it became adherent uterine gestation. to the peritoneal covering of three portions of the gut. The adhesions formed a firm support, and presumably the egg was for a short time carried safely. Eventually, however, it was broken in the peritoneal cavity, and the bird was shot, and owing to her unwillingness to take flight was forwarded as a case of suspected disease. Disease of the skin is a very rare thing in wild Grouse, and Di sea sesof generally results from the irritation produced by innumerable ectozoa, the skm ' such as ticks and lice. No. 1634 was an adult hen Grouse of 20 ounces, shot on August 12th, 1908 in Lanarkshire. The bird was very unprepossessing in appearance, as the feathers had failed to make their way through the skin of the head and neck especially, and to some extent all over the body. The skin was of a very deep yellow colour, and there were sebaceous cysts of varying sizes, scattered all over the bird, and so thick on the head and neck that hardly a feather appeared. The gamekeeper's view was that it looked " like a hen that 184 THE GROUSE IN HEALTH AND IN DISEASE had sat herself out on frosted eggs." There was no other abnormality dis- covered except the large size of the spleen which measured 20 mm. in length and 11 mm. in thickness. It is difficult to give any reason for this occurrence of sebaceous cystic disease of the skin. No other case of the kind has been brought to the notice of the Committee. It is somewhat analogous to acne, and it may pos- sibly have been preceded by an eczematous irritation of the skin brought about by Ixodes, the Grouse tick ; it resulted in any case in the failure of feather growth and disease of the glands which should have assisted in the process. The only other case which resembled it somewhat was Grouse No. 1792, where Ixodes and Goniodes had again produced a great number of scabs and sores and warty excrescences all over the face and head, and especially in the neighbourhood of the ears and eyes. CHAPTER IX "GROUSE DISEASE" History of "Grouse Disease" with an account of the work of the "Grouse Disease" Inquiry, in respect of previous work done by Professor Klein, Dr Cobbold, and others. By Edward A. Wilson and A. S. Leslie "GROUSE Disease" in its epidemic 1 form has become a serious matter only since the Grouse has come to be of importance in the economic management of estates in England and Scotland. Careful protection, improved conditions of food caused by heather-burning and drainage, and the removal, as far as practicable, of all animals that seriously affect the increase of the birds, are some of the artificial i s Gt rouse means by which moors have become more heavily stocked with Red Si^opro. Grouse than was the case under more natural conditions. To this teotlon? heavy stocking, combined sometimes with unfortunate natural conditions, but oftener with injudicious management, have been attributed the outbreaks of epidemic disease which have periodically visited the majority of Grouse moors. In other words "Grouse Disease" has always been considered to be intensified by artificial conditions. It is doubtful whether this view is correct ; as early as the end of the eighteenth century we have records of serious mortality amongst Disease the Grouse in certain districts, and "Grouse Disease" undoubtedly eighteenth occurred in the earlier part of the last century, long before the artificial c conditions had become established. It is therefore probably not correct to say that the first predisposing cause of " Grouse Disease" was protection leading to overstocking. The question is really 1 The familiar word " epidemic " is used throughout these volumes to signify outbreaks of specific diseases among Grouse in place of the more correct term " epizootic." 185 186 THE GROUSE IN HEALTH AND IN DISEASE of academic interest, since the artificial conditions are now firmly established, and it might be profitable to consider the other theories which have been put forward as to the predisposing causes of disease. Predispos- Such theories are numerous, and every one of them has at one time o"?< Grou S S e or another been promoted to the rank of "the real cause," the acting and primary cause, that is to say, of so-called " Grouse Disease." Before discussing their relative importance, however, it will be well to mention shortly what is known of the earliest appearance of the disease, and of its distribution in time and space. Among the earliest recorded outbreaks of disease about the beginning of Early last century, Macdonald, in "Grouse Disease," says : "It is now (1883) diseas d e S in f eighty 7 ears since tne alarm of ' Grouse Disease ' was sounded in this Grouse. country." l Speedy says : "The first time ' Grouse Disease' attracted special attention was in 1838. Prior to that date it was not unknown in Scotland ; but it had not assumed the proportions of a malignant epidemic. "Even in 1838 and for several years afterwards, it was much milder in its results than it has latterly become. In 1867 it seems to have developed a most destructive form, attracting very general attention. Prior to that it was comparatively local, decimating the birds in certain districts, and leaving other districts untouched. " : Howard Saunders says : " As long ago as 1815 a severe outbreak in the Reay country, Sutherland, was on record." 3 Mr Woodruffe Peacock in a pamphlet on "Grouse Disease" writes: "Old Moor Keepers have told me that their elders knew it as a slight and local trouble quite 50 years before 1847," i.e., in 1797. 4 And finally, in the MS. Records of Bolton Abbey, it is specifically mentioned as a "fatal disorder" in 1822 ; though as early as 1809 and 1811 there are records of "no shooting" accountable in all probability to disease. Of the distribution of "Grouse Disease" in space it is more difficult to speak shortly, and the question deserves very close consideration. Not ver y mucn na d been made of the subject up to the time of the Disease." commencement of the present Inquiry. It may be of use, however, to give an idea of the lines upon which the Committee has been working. 1 Macdonald, "Grouse Disease," p. 112. 2 "Sport in the Highlands and Lowlands of Scotland," p. 184. 3 "Zoologist", 1887, p. 302. 4 Rev. E. A. Woodruffe Peacock, "Grouse Disease," p. 12. "GROUSE DISEASE" 187 An attempt has been made to work out the distribution of disease in Grouse, both in time and in space, by first collecting records from every possible source, and as far back in time as it is possible to go. Each record is then allocated to its proper position on a map for its own proper year. By having a separate outline map of the British Isles for each year, on which every outbreak and every occurrence of disease is marked in red, it is possible at a glance to arrive at certain conclusions, e.g. : 1. How the incidence of disease changes from one set of counties or one district in one year to another set of counties or to another district in the next year ; thus the track of the epidemic from year to year can be distinctly followed. 2. The frequency of disease in each district is seen at a glance, and its rise and fall during the years which intervene between the periodic outbreaks can be followed. 3. The disease - incidence of each year can be compared with its weather record, and conclusions thus may be drawn regarding the predisposing causes, as well as the method of dissemination. 4. By combining a large series of annual disease-records on one map an idea is obtained as to which areas suffered most, and whether any areas are disease-free. 5. Such a combination of annual disease-record maps can be superimposed upon similar maps showing rainfall, watersheds, heights above sea-level, and surface soils or sub-soils, and so it becomes possible to recognise whether disease is in any way connected with one or other set of physical conditions. 1 " Grouse Disease" has long held the attention of many observers. Sportsmen and naturalists have done much for the field work, but the laboratory work has been less popular. Klein, Cobbold, Farquharson, Colquhoun, p rev i ous Andrew Wilson, and Young have all contributed towards an under- ^T^rouse standing of the pathology of " Grouse Disease," while Macdonald, r)isease -" Macpherson, Stuart-Wortley, Adams, Speedy, Teasdale-Buckell, and a host of other naturalists and sportsmen have supplied a large collection of interesting facts and observations, and an almost equal number of hypotheses and theories to account for them. It will be of use first to discuss the conclusions at which various writers have arrived, and as Klein's work stands out pre-eminently, and includes so great a proportion of what was known about " Grouse Disease" at the time, the simplest course will be to take his conclusions first. 1 For the results of this l>ranch of the Inquiry, vide vol. ii. Appendix I. 188 THE GROUSE IN HEALTH AND IN DISEASE Professor Klein came to the conclusion that there was a disease amongst _ , Grouse which took the form of an acute infectious pneumonia, and Professor Klein's con- was characterised by the presence in the lung of a specific bacillus of elusions. the B. coli group. The disease had, he believed, two classes of victims, one which died rapidly in plump condition and fine plumage, and another which died slowly with emaciation. He puts on one side the whole question of parasitic intestinal worms as having no particular connection with this epidemic pneumonia, and no causal connection with the mortality. Further, he agrees with the views of Dr D. G. F. Macdonald, and allows that Dr R. Farquharson was the first (in a letter to the Lancet, September 1874) "to state the opinion that the 'Grouse Disease' was of the nature of a contagious fever." Dr Farquharson's view as given in Macdonald's " Grouse Disease," was that the malady resembled an infectious or contagious epidemic fever. He considered that the finding of dead birds, "some plump and in good condition, and some reduced to skeletons," was in favour of the view " that the disease is of a specific or constitutional nature." Klein disagreed with Dr T. Spencer Cobbold's view that the epidemic "Grouse Disease" was due wholly to the presence of nematode worms. Dr Cobbold's view, was that "in the present epidemic" (1872), the disease was " entirely due to parasites," and that " the occurrence of these parasites in the intestines of so-called healthy Grouse does not destroy the notion Dr Cob- * boid's con- of disease from this source." " A strong bird," he says, " will overcome or elusions. . resist the irritation set up by the presence of hundreds of entozoa ; while a feeble bird, or one attacked before it is perfectly grown, will more or less rapidly succumb to the invasion. On these and other grounds, therefore, I do not hesitate to express the opinion that the present Grouse murrain is due to parasites. The irritation, probable distress and subsequent emaciation of the birds are readily explained by the presence of hundreds and thousands of strongyles ; and the mere circumstance that these parasites are very small, is quite sufficient to account for the fact that investigators have hitherto over- looked them." : "In one extreme case," he continues, "I particularly noticed a remarkable gorged or distended condition of the csecal villi, such as would result from continual irritation set up by parasites in overwhelming numbers. . . . There 1 Macdonald, " Grouse Disease," p. 129. 2 T. Spencer Cobbold, M.D., F.L.S., F.R.S. "The Grouse Disease," p. 15. London : The Field Office, 1873. "GROUSE DISEASE" 189 was no rupture of the capillaries, and consequently no extravasation in the caeca or in any part of the intestinal canal. That this congested state of the villi was due to the strongyles appeared the more certain, since the turgidity was only marked in that part of the ceecum where the strongyles were crowded together." l Dr Cobbold considered that the difference observed in the intensity of the disease during various epidemics might be partly accounted for by the presence of tapeworms and threadworms in varying proportions in the same Grouse, but that the strongyles were " sufficient by themselves to cause the death of the host " without the " assistance of a second kind of parasite." 2 Klein too recognised, not so much a different type of disease in different years, as two distinct phases of the same disease in the same epidemic, namely, that which is so acute as to kill birds in good condition without giving them time to lose flesh, and that which is so much less acute that it gives its victims abundant time to become emaciated before death. Cobbold, however, differed from Klein in one important respect, viz. : that he distinctly indicates that he did not observe any example of a Grouse dying in good condition and without loss of flesh. Neither Klein nor Cobbold suggest that they had any suspicion that they were dealing with two distinct diseases. Taking all these facts and opinions into consideration, the Committee at an early period adopted the provisional view that Klein and Cobbold Com . had before them Grouse dead from two distinct diseases (1) plump and well-conditioned birds which had died of an acute infectious pneumonia, i.e., the acute form of Klein's "Grouse Disease"; and (2) emaciated diseases - piners which had died of the results of extreme parasitism, i.e., of Cobbold's Strongylosis. The Committee kept in view, however, that since there is no reason why a bird already dying of Cobbold's Strongylosis tf reconcile should not become infected with, and succumb to, Klein's infectious pneumonia, it was possible that the piners examined by Klein might also be cases of the acute infectious pneumonia, which had stepped in and made an end of their already diseased existence. It would have been obvious to Dr Cobbold, if he had ever really seen a clear case of a Grouse which had died in good condition, well up to average weight, but with pneumonic lungs, that its death must have been due to some more acute cause than the mere presence of nematodes in the gut. 1 Cobbold, " Grouse Disease," pp. 24, 25. 2 Ibid. 190 THE GROUSE IN HEALTH AND IN DISEASE It was clear that Dr Cobbold's experience had lain entirely with emaciated birds, while Professor Klein as we know observed birds of all kinds ; but always from moors where the pneumonic disease appeared to be rampant. It had been generally noticed in past epidemics of disease that the first Character victims were of the emaciated type. It was only in the later stages of past epi- demics. o f the outbreak that birds in apparently robust health were said to have been found dead often " sitting on their nests." The Committee believed it not unlikely, judging only from the limited evidence before them, that the reason of this was that the acute pneumonic disease picked out first and made a clean sweep of birds already emaciated by Cobbold's Strongylosis. These piners would naturally be concentrated on the lower ground, and since their power of resistance to disease would be low any infection would naturally spread rapidly amongst them, while the more healthy birds on the higher beats, with a greater disease-resisting power in them, would be less prone to take the infection immediately, and also would be less readily discovered on the higher ground, even when the disease had proved fatal. This hypothesis appeared to account for a clean sweep of the piners all Might be over the moor, and for the distribution of their bodies in large forby'both numbers along the burn-sides, before the disease could reach the Cobbold's 6 healthy Grouse on the upper ground, or at least before the dead theories. bodies of Grouse on the high ground were discovered in any number. There appeared therefore in the early days of the Inquiry to be some reason for suspecting that both Klein and Cobbold had confused two separate diseases under the common title " Grouse Disease." And with regard to this point the Committee were probably in a better position to judge than those who had preceded them, in that the latter had begun and ended their work amongst innumerable dead and dying Grouse, the victims of a chronic wasting form of disease, often, it seemed, inseparably mixed up with the victims of a widespread epidemic of acute pneumonia. One thing was quite certain, that whereas the Committee had seen during Only one the first three years of the Inquiry extensive mortality amongst Grouse dis&ase caused by some agent which acted slowly and produced " piners " by S Com- on ly> they had not seen anything at all like an epidemic of acute or infectious pneumonia. It followed therefore that if the rapid "GROUSE DISEASE" 191 death of birds in good condition was typical of Klein's disease no case of Klein's disease had yet been seen. At this date the only form of disease observed was a very widespread mortality of "piners" owing to what appeared to be a form of starvation resulting from a chronic congestion of the csecal mucosa. This Character i. . m ,1 , of disease condition of the mucosa was produced by an excessive number of observed the nematode worm known as Trichostrongylus pergracilis in the mittee. caeca, and was quite comparable to the form of " Grouse Disease " described by Cobbold. The view that two distinct forms of disease had for many years past been confused under one term was supported by the literature of the Committee's subject, for all previous writers on Grouse and "Grouse Disease" had ported by referred to a difference in character to be noticed between the disease ture. outbreak of one year and that of another, or between the appearance of the victims at one season and another in the same epidemic. By adopting the view that two distinct diseases had been confused, much of the disagreement which had been in evidence from the earliest days, as to the predisposing causes of " Grouse Disease," could be explained. The following abstracts suggest that there were two different agencies at work destroying Grouse in large numbers. William Houstoun of Kintradwell, Brora, for instance, says: "At that time it took the tapeworm type, and the birds all came down to the seashore to pick up particles of salt; but, when the disease next appeared, it had a different form, and I fear we are as far as ever from a solution of the cause. I opened three birds in the last stages of the disease" (the pining form) "and they all presented the same appearance. The liver like a clot of coagulated ink; intestines distended with a yellow feculent matter; and crop full of undigested but fresh and green heather tops." 1 These were presumably cases of Cobbold's Strongylosis, since the distension of the intestines "with a yellow feculent matter" suggests the appearance characterising the caeca in that disease, and the victims were all piners. Again, Macdonald, in his book on "Grouse Disease," described the earlier stages of the epidemic as being much more virulent, the birds being found dead and dying in numbers by the water-courses, "which latterly was not the case." The plumage in the earlier attacks looked different, the feathers were dirty 1 Macdonald, " Grouse Disease," p. 140. 192 THE GROUSE IN HEALTH AND IN DISEASE and draggled an appearance which was " latterly not seen in diseased birds." l And again, quoting from "Land and Water" (1867), he says that "one striking difference between the disease of 1867 and that of former years was that the dead birds . . . picked up this season were so plump and in such excellent plumage that they had the appearance of healthy birds ; whereas in former years the diseased birds were most characterised by disordered plumage and attenuated bodies." 1 From this the Committee surmised that the disease which occurred in 1867 was Klein's pneumonia ; while in the previous records the birds had been victims of Cobbold's Strongylosis. This provisional view was again borne out, by a letter written by Mr Macdonald to the Times, May 12th, 1873, which ran thus : " It seems that disease of an exceedingly virulent kind prevails in all parts of the Highlands, and in a form hitherto unknown. ... In 1847, 1856, and 1865 the infected Grouse exhibited a ' dull disordered plumage and attenuated bodies.' ... In June 1867 they showed good plumage, a healthy appearance, and were perfectly plump, although the liver was soft and discoloured. This year (1873) they are beautiful in plumage, but wasted to skeletons . . . and with full crops." 3 This occurred evidently in later autumn, since mention is made of the large quantities of berries in their crops. All these quotations seemed to point to the fact that in 1856 and 1865 there was an excessive mortality from Cobbold's Strongylosis; whereas in 1867 there was an epidemic of Klein's acute infectious pneumonia. In 1873, the birds which were seen late in autumn were presumably recovering, thanks to a full diet of berries, or, if found dead, were to be considered cases of Cobbold's Strongylosis killed by Klein's pneumonia. They may have survived an attack of acute pneumonia which the Committee were prepared to believe had raged that year, but they certainly were also victims of Cobbold's Strongylosis ; and the fact that their plumage was in good order seemed to show that they were at any rate sufficiently convalescent to complete the growth of their winter plumage after moulting. Macdonald writes : " We have ourselves frequently picked up dead Grouse perfectly plump, and in excellent plumage one season, and in the next season found diseased birds with attenuated bodies and dull disordered plumage." 4 1 Macdonald, " Grouse Disease," p. 127. 2 Ibid., p. 155. 3 Ibid., p. 155. Ibid., p. 131. "GROUSE DISEASE" 193 Again, in Adam's " Reminiscences " we find : " Disease in this attack (Dalnawillan, 1882) was very different in its aspects from former attacks. It came on very suddenly, sharp and decisive ; but on this occasion I have no doubt but that it had been hanging about all through 1881, and also in the spring and summer of 1882, steadily wearing away the birds bit by bit." The distinction is markedly contrasted by Adams in his book, and the incidence in each case is well described. Tom Speedy in "Sport in the Highlands and Lowlands of Scotland" writes : "The epidemic assumed two different forms. In some cases the birds were draggled, wasted, and emaciated, bare about the legs, and indicating ... a long continued or fatal disease. At a more advanced period of the season they were found dead in beautiful plumage, with fine feathery legs ; and the red above their eyes unsullied and as bright as vermilion. In many cases they were seen the one day seemingly in perfect health, and the next day stiff and cold in excellent condition." ' Enough has now been quoted to show that in the minds of many observers there has been for years the suspicion that the differences observed were not merely two phases of one form of sickness, but two distinct diseases. And it was on this assumption that the Committee at first commenced their investigation. The widespread idea that tapeworms are at the root of one form of trouble is perhaps natural, considering that it is common knowledge that in some animals they are the cause of serious wasting. Moreover, the very Tapeworms first thing that appears when a Grouse is opened up, whether purposely cau'se'of or accidentally, is a mass of large white tapeworms. What could be more natural, since the bird is wasted to skin and bone, and tapeworms are found in large numbers, than to consider the one to be the cause of the other. But if only threadworms were as conspicuous as tapeworms, outnumbering them as they often do, to an almost incredible extent ; or if some distinction had been earlier recognised between the main gut of the Grouse and its caecal appendices, there would before now have been a strong following of Dr Cobbold, and the pining form of disease would be more readily associated with the presence of the smaller worm. The Committee's provisional belief in the existence of two distinct kinds of 1 Adam, " Reminiscences," p. 75. 1 Op. tit., p. 185. VOL. I. N 194 THE GROUSE IN HEALTH AND IN DISEASE No case of " Grouse Disease" appeared to be justified up to a certain point, but disease yet as there has as yet been no outbreak of Klein's epidemic pneumonia within the Committee's knowledge, it was impossible to speak positively upon the subject. Klein, of course, had "piners" to work with as well as "birds that died in good condition " before they had time to pine ; but as already stated he came to the conclusion that they exemplified two phases of the one disease. It appeared quite reasonable to believe that in an epidemic of the infectious pneumonia some of the birds might survive long enough to become piners ; therefore the Committee were prepared to accept Klein's explanation in so far as it applied to the birds which he had the opportunity of examining. But it could never happen that uncomplicated cases of Cobbold's Strongylosis should die plump and in good condition. Loss of All birds dying from Strongylosis must be "piners." because weight an invariable their death results mainly from an inability to absorb nourishment accompani- ment of owing to the csecal mucosa being damaged. The consequent emacia- Cobbold's disease. tion is a sine qua non in the diagnosis. The weak point, as it appeared to the Committee, in Klein's argument was that he makes no adequate mention of the ceecal lesions caused by the Weak point Trichostronqylus , lesions which in the majority of adult birds examined m Klein s . theory. by the Committee have been the most prominent, indeed the only prominent feature upon dissection, and which the Committee believe to be at the root of the whole question. Before proceeding further to discuss this point it will be well to look into the accounts of dissections which have been recorded from time to Records of time (many unfortunately in the most cursory manner), with a view previous v _ dissections, to seeing what pathological lesions were found to account for death. Klein's work is again in many respects far ahead of all the rest ; and as it is necessary to go into it in some detail it will be better first to glance at the work of others. Dr Cobbold's notes on the pathologj^ of " Grouse Disease " have already been quoted ; * but reference must again be made to a description which he gives of the caeca in an "extreme case" dissected by him. 1 See p. 188. "GROUSE DISEASE" 195 " In one extreme case," he says, " I particularly noticed a remarkably gorged or distended condition of the csecal villi, such as would result from continual irritation set up by parasites in overwhelming numbers. . . . There was no rupture of the capillaries and consequently no extravasation in the cssca or in any part of the intestinal canal." This condition of the caecal villi is very typical of extreme Strongylosis as observed by the Committee, just as the same engorged condition to a lesser degree of the intestinal villi is typical of Helminthiasis generally. Nor is it by any means so rare as one might gather from Cobbold's description. Yet Professor Klein makes no mention of any condition at all approaching it in character, in any of the birds examined by him, though he allows the almost universal infection by the Trichostrongylus. Professor John Young wrote a paper on Certain Aspects of the Grouse Disease, in the " Natural History Proceedings of the Glasgow University," vol. i. (quoted in Macdonald's "Grouse Disease"). 1 Unfortunately, he Pro- fGSSOl* J does not differentiate between the different portions of the intestine ; Young, but he appears to have had a most abnormal series of birds to examine. In two of three Argyllshire birds he found general peritonitis due to perforation of the gut which must have occurred a sufficient length of time before death to allow of adhesion and short circuiting. Dr Andrew Wilson is also represented as having satisfied himself "by repeated dissections and careful observation that a markedly congested appear- ance of the mucous surface and of the digestive and respiratory tracts was almost invariably present in birds which had been found dead." 1 John Keast Lord and Frank Buckland are represented by the same indefatig- able collater as having "satisfied themselves that the disease was dis- j h n organisation of the liver accompanied by inflammation of the chest a n,jF r viscera." The pity is that we can never know what amount of exact Buckland - observation these vague descriptions really covered. As they stand they cannot be considered of any value. Tom Speedy writes as follows rather more to the point : "In post-mortem ex- amination in a number of birds we discovered intense inflammation of the bowels ;. while by the aid of the microscope, immense quantities of strongyle were Tom discernible in the inflamed parts . . . such cases were exceptional when 8 P eed y- contrasted with that other more loathsome form of the malady which seems 1 Macdonald, "Grouse Disease," p. 141. 2 Ibid., p. 145. 196 THE GROUSE IN HEALTH AND IN DISEASE to have been much more contagious." 1 By "the other" more loathsome form of the malady he meant the acute disease which killed off birds while still in excellent condition ; and, it is interesting to note, that, during this epidemic, cases of "Cobbold's Strongylosis," such as he first described, were apparently exceptional. It is easy to see how incompatible was much of this with what the Committee had seen of " Grouse Disease " during the first few years of the Inquiry, during which " Cobbold's Strongylosis " had been in many places abundant, and Klein's acute infectious pneumonia had been not only exceptional, but non-existent. Turning now to Klein's account of the pathology of " Grouse Disease," and remembering that he considered both the piners and the birds that died in good condition as alike victims of an acute infectious pneumonia, we find Klein. a very definite statement of pathological signs and lesions which he diagnosed as the acute pneumonic disease. " One of the most prominent pathological changes in the diseased Grouse is an acute congestion of one or both lungs, and this change, whether very severe or less severe, is independent of the presence of Strongylus." ' This implied absence of Strongylus is difficult to accept as a fact, notwith- standing Professor Klein's statement and the general accuracy of his observations. The Strongylus is almost universally present in the Red Grouse of all ages, Strongylus as *^ e Committee has been able to ascertain by the examination of some ve"safin ni ~ two thousand birds from every part of the United Kingdom. When- ever a case occurred in which its presence was not at once evident, a special search has almost invariably revealed it. Dr Andrew Wilson came nearer to the truth of this matter when he stated that " in one or two doubtful instances only could it be asserted or suggested Dr Andrew ^ at none f tne round worms were present." He nevertheless puts Helminthiasis aside, and believes that the " Grouse D'isease " is in the main an infectious fever. He does this, moreover, with every show of good reason, and in words to which we can hardly take the smallest exception, save that he makes too light of the trouble which we now call Strongylosis. He says, for example : " Outside the parasitic hypothesis, applicable as that theory is to a certain class of cases, there lies, I am convinced, the great bulk of fatal instances, the exact cause of which fatality must be sought for in some lesion analogous to that involved in the idea of the epidemic theory." 3 1 Speedy, " Sport in the Highlands and Lowlands of Scotland," p. 185. 2 Klein, "Grouse Disease," p. 6. 3 Macdonald, "Grouse Disease," p. 148. "GROUSE DISEASE" 197 He was handicapped by this belief in the epidemic theory, but we have to confess that it is difficult to accommodate his observations to the belief in Strongvlosis, for he says that there was an " absence, in most cases, of the signs of fatal parasitism, such as inanition producing the pining condition, actual perforation, morbid appearance of the muscular tissues, etc." l For if most of the cases that he examined were marked by an absence of inanition, they differed very materially indeed from all the cases of birds found dead or dying within the years of the present Inquiry ; almost all of which were " piners " to a greater or less degree. But, writers kept no like all other early writers, he produces no particulars as to weights, record of . . -IT i weights. and in the absence of these it is impossible to accept as a fact that inanition was absent, knowing as we now do, how exceedingly misleading are the external appearances of many of these cases. Klein did not believe in two distinct diseases, and described the autumn and winter cases as having pathological appearances identical with . those found in the unwasted Grouse which had died of disease during not recog- nise two the spring and early summer. He believed these autumn and winter distinct diseases. victims to be sporadic cases of " the real Grouse Disease," which occurs in the spring and early summer. Nowhere throughout his whole book can any suggestion be found that goes even so far as Dr Andrew Wilson's view, tha-t a few birds at least may succumb to Strongylosis, or even to general Helminthiasis. Klein appears to include all the Grouse which he described with the appear- ance of a pneumonic lesion in the lung, at any time of the year, as victims of the true " Grouse Disease," and by this he meant in every case the acute infectious pneumonia which he was the first to describe in detail, but which the Committee now believes has no existence, and was founded on a misinter- pretation of post-mortem changes in the dead bird. What then were the appearances upon which he relied in making a diagnosis- of acute infectious pneumonia ? The points He sums them up once or twice on pp. 15-19 of his book on , ^ -p.- >i his theories. Grouse Disease. " The chief changes are undoubtedly those found in the lungs. " (a) In emaciated birds the disease of the lungs is, as a rule, but not without exception, not very extensive, only a portion of one or both lungs being congested. 1 Macdonald, "Grouse Disease," p. 148. 198 THE GROUSE IN HEALTH AND IN DISEASE " (6) In the majority of instances in which the dead birds are found plump .... the lungs show a great deal of congestion. "The lungs show deep coloration in the greater part of either one or both organs, the hind portions being, in these cases, the ones chiefly affected ; or both lungs are uniformly congested, being in some cases of a dark purple-red colour. " On microscopic examination of the lung, Klein finds " that in the con- gested parts the large and small vessels are uniformly distended and filled with blood, and that the air spaces of the more deeply affected parts are uniformly distended and filled with a homogeneous or granular exudation, or with blood, so that in these parts we have a solidification of the lung which compares with the condition known as the red hepatisation in pneumonia. There is, however, no fibrine in the form of threads noticeable in the air spaces ; the smaller air spaces contain blood en masse, while the large ones are filled with a homogeneous albuminous exudation. From this we con- clude that rupture of small vessels had taken place during life."' To continue further with the pathological signs to which Klein has drawn attention, " the larynx and trachea," he says, " exhibit a change in the mucous membrane, which is of a dark colour, and hypereemic, and this is the more pronounced the more marked the lung-change. The spleen is not enlarged, and appears of a dark colour. " The liver is uniformly congested and soft ; it is either of a dark red colour, or appears almost black. On microscopic examination the large blood-vessels as well as the capillaries of the lobules are distended and filled with blood corpuscles. In some cases the liver, on post-mortem examination, is blackish, or rather is of a dark olive-green colour. In these instances the liver cells appear granular and more or less disintegrating, and contain dark brown pigment granules, while the capillary blood-vessels are filled, not with blood corpuscles, but with masses of amorphous pigment, the result of stasis and disintegration of the blood corpuscles. " The kidneys are congested, in some instances leading to haemorrhage into the tissue of the kidney. " The intestinal mucous membrane shows patchy congestion, and the same is the case with its serous covering, which in most instances is congested in many places, sometimes to a considerable extent. In some cases the peritoneum appears very moist in these localities ; that is to say, there is a small amount of exudation. i Klein, "Grouse Disease," p. 15. "- Ibitt., p. 17. "GROUSE DISEASE" 199 " I have seen a few cases in which haemorrhage has taken place, showing itself in the form of petechise in the peritoneum." 1 These appearances which Professor Klein believed to be diagnostic of the acute infectious pneumonia are summarised on page 44 of his book, as follows : " The congestion of one or both lungs, the congestion of the liver, the small dark spleen, and the patchy redness of the intestine and the peritoneum," and one may add, the presence of the specific bacillus in the lung and liver of affected birds. Although the bacillus is not present in the circulating blood of birds affected during the spring and early summer outbreaks, appearing then mainly in the lungs and liver, they are to be found, he tells us, in the circulating blood of birds that have died in the autumn and winter. He believes, of baSifus moreover, that the latter are the sporadic cases which keep the disease lingering through the winter, ready to break out in a spring or summer epidemic, though the vitality of the microbe is such that it probably requires no such active assistance from individual birds. It will be seen that it appeared impossible for the Committee to accept unconditionally the views of any of their predecessors in the work ; but it seemed equally impossible to discredit altogether the reliability of detailed observations made by many workers of high standing. At this stage of their investigation the Committee still believed that Klein's " Grouse Disease" was an established fact (though his diagnosis might require revision), and spoke of it as the " true epidemic Grouse Disease," or " Klein's acute infectious pneumonia." At the same time, the Committee believed it to be an advantage for them to see one disease at a time, and began to distinguish Cobbold's Strongylosis as a specific disease apart from Klein's acute infectious pneumonia. The foregoing resume is necessary in order to show the position of the controversy when the Committee of Inquiry was beginning its work. It explains many of the unavoidable errors into which the Committee was led by the inaccuracy of much that had been published on the subject. Even Professor Klein's work, accurate and painstaking as it was, and clear causeof as were his published descriptions of whatever he himself saw, was K^efn^s r misinterpreted by him for the sole reason that bacteriology (a science error - of which he was one of the most honoured founders) was still in its- infancy. His deductions as to the disease being an acute infectious pneumonia due to a specific bacillus have now been shown to be founded upon a misconception ; 1 Klein, " Grouse Disease," p. 19. . 200 THE GROUSE IN HEALTH AND IN DISEASE but, in the days when he was working at the subject, no one could have arrived at other conclusions than those to which he himself came. It is due to so great and careful a worker to say that at that time he was years ahead of any other bacteriologist. That he should since have been found to be in error merely shows how dependent is science upon the methods available at the moment, and how impossible it is for any one at any time to be certain that even the most probable explanation of observed facts is the right one. It has been thought necessary to set forth the different stages of opinion through which the Committee has passed in order to account for many mittee's provisional conjectures, since shown to be faulty, as to the cause of diagnoses death in birds that were submitted for examination in the earlier incorrect. -, /, , , T days oi the Inquiry. From the first it was thought advisable to acknowledge the receipt of every bird sent to the officials conducting the Inquiry, and, where possible, to account for its death or its sickness, or for any abnormality which it presented. In the earlier days the field-observers believed firmly in Klein's view that " Grouse Disease " was an acute infectious pneumonia, and in a few isolated cases they believed that the lesions described by him with so much detail were present. They thereupon made the necessary diagnosis and sent in their report, and for the next week or two awaited an inundation of dead birds showing similar lesions. But no epidemic occurred and the inundation did not happen, and by degrees it became evident that there was something doubtful about the view which had been provisionally adopted. This doubt was confirmed when the bacteriologist, Dr Seligmann, found that the bacillus which Professor Klein considered to be the specific cause of Klein's Grouse pneumonia was in fact only to be discovered in any number foundtobe some twelve or twenty-four hours after death. It became gradually ^rtem P St c l ear tna * no ^ or ^J ^ e g rosser appearances in the lung which Klein change. considered to be due to pneumonic congestion, but the microscopic appearances of the lung - tissue in section, as well as the colonies of bacilli which he described and figured in the lung, were in fact only to be found some hours or days after the death of the bird. They were undoubtedly due to a post-mortem migration into, and colonisation of, the tissues in question by numbers of Bacillus coli which had escaped from their proper sphere in the intestine at the moment when the normal defence had broken down. It gradually began to dawn upon the Committee that the appearances in "GKOUSE DISEASE" 201 the lung upon which Klein had relied in making a diagnosis of acute infectious pneumonia differed in no way from the appearances which had been ^,!acter observed by the Committee in the lungs of hundreds of birds found jstics found in all dead dead from all causes, including Cobbold's Strongylosis, general birds - Helminthiasis, accidents, or even shot wounds. Klein describes accurately the post-mortem changes leading to a discoloration of the lungs which invariably take place. These begin, almost always, where the lung is in contact with the liver, and strongly suggest (what at first the Committee frequently mistook it for) congestion and pneumonia. This discovery undermined the faith which the Committee were prepared to place in the existence of Klein's acute infectious pneumonia, and it soon became evident that in birds obviously dying of " Grouse Disease," there was no dangerous ante - mortem infection of the lung or other tissues with the bacillus in question, and no recognisable lesion in any organ of the bird except in parts of the intestine. All the appearance of congestion and pneumonia in the lung, the " inky " or " tarry" appearance of the liver, the small dark spleen and the several other characteristics which were previously attributed to Klein's pneumonic disease, were now found to be due to post-mortem change alike evident in diseased and in perfectly healthy normal birds. The point was further tested by taking a number of healthy pigeons, and killing the whole of them at the same time with chloroform. The birds were numbered and opened on consecutive days and the change ment in the appearance of the viscera was noted. It was evident that in healthy every case where there had been extravasation of blood or serous fluid owing to rough handling, or damage by the knife in dissecting the pigeon, the tissues of the lung became black, and took upon themselves precisely the same appearance that is seen in a Grouse found dead upon the moor, or examined some days after being shot. The appearance of pneumonia was evidently due to a soaking of the lung-tissue in decomposing blood and serum, and the post- mortem colonisation of the tissues by Bacillus coli. 1 Once this fact became clear, the Committee was no longer burdened with the task of recognising and investigating the type of " Grouse Disease " described by Professor Klein, for it now became impossible to accept his be investi- gated by explanation of the disease. This being recognisedit became necessary to set the Com- on foot more detailed investigations to determine the following points : 1 Vide also chap. xii. pp. 273 et seq. 202 THE GROUSE IN HEALTH AND IN DISEASE 1. To prove that the amended view of Klein's work was the right one, and that the "Grouse Disease" which he saw and described as a form of infectious pneumonia was in reality not different to the "Grouse Disease" which the Committee were seeing constantly, and were describing as Cobbold's Strongylosis. 2. To make every effort to obtain fresh and living samples of wild Grouse actually suffering from " Grouse Disease," for systematic laboratory work, with a view to discovering whether this or any other wide- spread form of " Grouse Disease " was caused by bacterial infection or not. 3. To complete the investigation of the Grouse parasites, ectozoa as well as entozoa, with a view to determining whether by any possibility " Grouse Disease " could be considered attributable to some of them, or even to one of them. 4. To investigate the blood of the Grouse in health and in sickness, and especially to try and discover the presence of toxaemia with its resultant anaemia and changes in the respective proportions of leucocytes. It was thought possible that the toxins produced by Helminthes in the intestine might be the cause of some increase in the eosinophil corpuscles. 5. To make certain that " Grouse Disease" did not result from the presence in the intestines, or in the blood, of any protozoan parasite for the transference of which we knew the Grouse had ticks, bird -lice, flies, fleas and other external parasites. 6. To make a complete and special investigation of the life-history of the Trichostrongylus pergracilis or the Strongyle of Cobbold, with a view to understanding its mode of infecting Grouse, its action when in the caecum of the Grouse, its method of reproduction, its dis- semination, and the conditions which enable it to hatch from the egg, to pass from the larval stage to encystment, to survive on a Grouse moor, and to ensure its being swallowed by the bird at a stage when to be swallowed means completing the cycle of parasitic life, instead of being merely digested. The life history of this threadworm was obviously required in its smallest details, in order that Strongylosis might be understood. How these various questions were dealt with may now be explained. "GROUSE DISEASE" 203 During the period of the Inquiry all the birds that have passed through the Committee's hands, have been examined as carefully as circumstances allowed at the moment. Every bird, almost without exception, was dissected, and the more important points were noted and tabulated, providing in this way a very considerable mass of observations from which to deduce averages, construct tables and curves, and so obtain information which had previously been inaccessible. 1 In addition to this, in the majority of the more interesting cases, parts of the various organs, as well as the contents of the different portions of the alimentary canal, were submitted to microscopic examination. The tissues were hardened and cut, and a very large number of sections examined microscopically, not by one member of the staff alone, but by a number of workers qualified to give an opinion upon what they saw, so that bit by bit a true reading of the observed facts was attained. One or two questions regarding Professor Klein's work were to some extent settled by the bacteriological work which Dr Seligmann carried out in the first two years of the Inquiry. Dr Seligmann, before resigning his position conclusions as Bacteriologist to the Inquiry, on leaving for Ceylon in December bTtecterio- 1907, wrote an interim report of his work in which he gave his lo s ists - provisional conclusions. Dr. Cobbett and Dr. Graham Smith were then enlisted on behalf of the bacteriological work, and their results are to be found in detail in chapter xii. They came to a very definite conclusion as to the absence of pneumonia in the birds which they examined " in a perfectly fresh condition, the lungs being always pale pink in colour and free from congestion." They ascertained that the redness of the mucosa of the cseca was obviously not a post-mortem change. They concluded further that diseased birds as a rule have a very large number of Trichostrongylus, whereas healthy birds may have but few, and do not very often have a large number. They also came to the definite conclusion that " ' Grouse Disease' is not an infection with those bacteria" which find their way in limited numbers into the organs of birds which contain Trichostrongylus. They have not been able to satisfy themselves that the bacilli which find their way into the organs do much harm. Some harm no doubt they do ; but how much they cannot say. 1 A complete list of all birds examined, with a note of the principal lesions observed, is given in Appendix B. 204 THE GROUSE IN HEALTH AND IN DISEASE Adam's view is that a potent cause of disease is the "constant absorption of small quantities of bacteria," hence the question put by Drs Cobbett and Graham Smith, " Is it a toxaemia caused by the poison liberated from bacteria which have been absorbed from the intestine, and which have almost immediately perished in the tissue ? " Their work has all tended to the view that Klein's observations required revision in the light of modern work in bacteriology, that his deductions required amendment, and that " Grouse Disease " is not an acute infectious pneumonia. Can we then believe that there is an epidemic form of "Grouse Disease" which in spite of minute inquiry and search has eluded the vigilance of the Inquiry during the last six years ? Drs Cobbett and Graham Smith (see p. 274) go the length of saying : " It is, we suppose, just possible that we never came across the genuine epizootic 'Grouse Disease' at all." Apart from the question of whether Klein's pneumonia has any existence AH "Grouse * n rea ^*y> a ^ the outbreaks of disease amongst Grouse which have Disease" come under the observation of the Committee can be ascribed either either strongylosis t o Strongylosis or to Coccidiosis. the only two diseases which the or Cocci- OJ * diosis. Committee now recognise as causing widespread mortality amongst Grouse. It is quite clear that one of the most important signs of disease, whether it be Strongylosis or Coccidiosis, is a loss of weight. And this loss of condition, Loss of even to emaciation, which follows on Strongylosis, is a character to character- which full prominence is given by all writers about " Grouse Disease," these f b th though no measurement of actual weights had ever been recorded so diseases. f ar ag wag k nown before the present Inquiry began its work. The omission to record weights in the past is the more to be regretted because the chief characteristic of the only other form of "Grouse Disease" which has been reported is the fact that the weight of birds that have succumbed to it remains normal. Probably one of the most persistently quoted observations, which many Theory that s P or tsmen and gamekeepers still maintain to be a fact, is that in some Grouse epidemics there is a certain proportion of birds which succumb to so acu te and virulent a form of "Grouse Disease" that they die condition. Before an y i oss O f fl es h or weight can have time to show itself, and before any change in the appearance of the feathers becomes manifest. "GROUSE DISEASE" 205 This view is founded not on actual measurement of weight, but on the bird's general appearance of good feather and normal weight, as estimated by the observer who takes the bird in his hand when it is found dead on the moor. In most alleged outbreaks of "Grouse Disease" the birds have been collected and burned, or buried by the score in a soft moss-hag or under a rock. They were never weighed, and never carefully examined. Yet without careful weighing and examination it is impossible to come to any reasonable conclusion as to their condition or the cause of their death. The Committee's field-observer has himself been present on several occasions when such birds have been picked up and passed from one to another of the keepers and the ghillies ; full-feathered, richly-coloured hens, perhaps found almost warm but dead upon their nests. And these birds have been weighed in the hands and their weight guessed as fully normal, notwithstanding the condition of the breast, yet the spring balance has invariably proved appearances deceptive, except in the cases where accident has been the cause of death. If the case is a hen whose feathers have been recently donned for nesting a most misleading impression of good condition is given even in a wasted bird, where the plumage has not been drenched with rain or bleached by sunshine. In the cocks it is different, for the feathers have not been changed for the nesting season, and the plumage is often worn and faded in comparison with the new, nesting plumage of the hen. 1 It is often hard to believe that a hen Grouse which has died in full nesting plumage, however thin and poor, is not actually heavier than the dingy cock bird of the same month. And if no rain has fallen on the hen since her death the comparison between her and the cocks which are found in all stages of disease, decayed, weathered and bleached, is even more misleading. The point has now been too often tested to allow of doubt. No bird dies of Strongylosis without loss of weight. That some birds waste more and some less before succumbing to the disease is certainly true, the difference in this respect depends mainly upon the season ; yet it must be conceded that sex and individual strength also make a difference. 2 On one point the Committee can speak with entire confidence. During the whole period of the Inquiry, from 1904 to 1910, there has not been a single outbreak of "Grouse Disease" in which the birds died without loss of weight. 1 Vide chap. iii. 2 Vide chap. vi. p. 142. 206 THE GROUSE IN HEALTH AND IN DISEASE While, therefore, it is possible that the virulent form of disease does, in fact, sometimes occur, it is also possible that the belief in it is entirely without justification, and is the result of inadequacy in method and inaccurracy in observation. During the investigations of the Committee's observers, an interesting side- light has been thrown on a possible connection between Coccidiosis and the earlier work of Tegetmeier on pneumo-enteritis. In some Grouse-chicks dying of intestinal Coccidiosis, cysts were found in the bronchioles, bronchi, and trachea, but not in the lung-tissue itself, while the lungs of the young birds exhibited apparent symptoms of pneumonia. The coccidian cysts in the bronchioles might be capable of setting up sufficient irritation to account for the pneumonic symptoms. It is possible that there may be here some explanation of the pneumo-enteritis of earlier writers. CHAPTER X " GROUSE DISEASE " CONTINUED STRONGYLOSIS l PART I. THE THREADWORMS (Nematoda) 2 By Dr A. E. Shipley PART II. ON THE DEVELOPMENT AND BIONOMICS OF T&ICHOSTRONGYLUS PERGRACILIS By Dr Robert T. Leiper (I.) Family Strongylidae (i.) TRICHOSTRONGYLUS PERGRACILIS (Cobbold) Synonym : Strongylus gracilis Cobbold THIS round-worm was first described under the name of Strongylus pergradlis (Cobbold), by Cobbold, 3 whose words we quote : " Characters.- Body filiform, finely striated, gradually diminishing in front, uniform in thickness below ; head bluntly pointed, with a simple oral aperture ; tail of the male furnished with a bilobed bursa, each half supporting four pointed rays ; -spicules two, thick, and slightly divergent ; tail of the female slightly swollen above the subterminal anal orifice, rather sharply pointed at the tip ; vaginal opening situated at the upper part of the inferior sixth of the body. " Length of male ^ inch to f inch ; body T $ Tr inch in diameter, tapering anteriorly to -j^nnr inch at the head ; greatest breadth immediately above the bursa inch. 1 The term " Strongylosis " is employed in this chapter to denote the disease caused by Tricho- strongylus peryracilis (Cobbold) ; though it would perhaps be more strictly correct to name the disease Trichostrongy losit. 2 Reprinted with slight alterations from the Proceedings of the Zoological Society of London, 1909. 3 Cobbold " Grouse Disease," p. 16. 207 208 THE GROUSE IN HEALTH AND IN DISEASE "Length of female mostly f inch, sometimes very nearly inch; breadth above the tail -JTTF inch to -z^ inch, narrowing at the extreme point to ^^^ inch ; longitudinal diameter of the eggs -rl^ inch, their breadth being TTSTS inch." Eight years later Cobbold described, 1 under the name of S. douglassii, a nematode which occurred in great numbers /n the proventriculus of certain South African ostriches. Their presence was associated by the ostrich-farmers with a certain amount of disease, and with some deaths. Finally, we have the species S. quadriradiatus recently described by E. C. Stevenson. It occurred in considerable numbers in the intestines of a flock of fancy pigeons which had been almost destroyed by a malady of unknown origin early in 1904. In his article upon this disease, Stevenson points out that the presence of a few nematodes in the caecum of the pigeon causes little harm. If, however, the threadworms exist in large numbers, disease becomes manifest. This Stevenson attributes to two causes : the first is the loss of blood ; but there is, I think, little or no evidence that these nematodes live on blood. The second cause is the piercing of the walls of the intestine, 5 which permits the bacteria in the contents of the alimentary canal to make their way into the peritoneal cavity, where they set up peritonitis. Evidence is gradually accumulating as to the occurrence of this, and some of the French authorities even think that such a perforation, made as a rule by Trichocephalus trichiurus (dispdr), is one of the more common, if not the most common, causes of appendicitis in man. The presence of these worms further sets up an inflamed, catarrhal condition of the walls of the intestine, which leads to a debilitating diarrhoea and to general disorders of the digestive system. As in other cases, the nematodes doubtless give off toxins, the effect of which is largely confined to the nervous system and to the cells in the blood of the host. The genus Trichostrongylus has recently been established by Looss 3 to include certain forms which he has separated out from the large genus Strongylus. The Strongylus pergracilis of Cobbold corresponds so closely in structure with the species described by Looss that I think there can be no doubt that it also should be included in the new genus. The suggestion made above 1 Journal of the Linrusan Society, London, " Zoology," xvi., p. 184, 1883. 2 An actual perforation of the membrane is not in all cases necessary. There are examples of bacteria traversing the wall or parts of the wall of the alimentary canal which have been locally or temporarily weakened in some way. ' " Centralblatt fur Bakteriologie, Parasitenkunde," xxxix., p. 409, 1905. PLATE XXXIII. ph..- I Fio. 3. Unsegmented egg. Egg with two blastomeres. Egg with four blastomeies. E-'g with eight l>lastomeres, only six showing. Egg with blastomeres, all showing. Egg with sixteen hlastomeres. Egg with thirty-two blasto- meres. Egg with sixty- four blastomeres. Egg with coiled- up larva, ripe for hatching. A similar egg, artificially ruptured, and the larva in the act of escaping. This shows the contraction of the egg-shell when ruptured. u,t- .! \ s fir i. 2. FIG. 1. Male Triclw- strotigylus pergracilis, showing m mouth, ali- mentary canal, spicules, and genital bursa. Magnified. FIG. 2. Female T. per- gracilis, showing an. anus ; c gl. cephalic glands ; m. mouth ; oe. oesophagus ; of. ove- jectur ; o. ovary ; j>h. pharynx ; r. rectum ; >(/. uterus with segment- ing eggs ; v. vagina. Magnified. FIG. 5. A female Triehosoma lonyicolle Magnified about seven times. Fio. 4. Three specimens of female Triehosoma longicoUe. Magnified about twice. TJtICHOKTJtONGYLUS /'KlfdlfACILIN AND TKICJI080MA LONGICOLLE. 1 1], ;if,.S'l7f p. 200.] " GROUSE DISEASE " STRONGYLOSIS 20? that Strongylus tennis Eberth of the goose should also be reckoned as a species of Trichostrongylus was made to me by Dr R. T. Leiper. Specimens of T. pergracilis are found in the caeca of most Grouse. They are apt to cover themselves with mucus and dirt, and are consequently hard to see and often overlooked. We have found them, with hardly an exception, in every one of the two thousand Grouse examined. 1 They are rendered opaque and white, and hence much more apparent, by shaking up the contents of the caecum in 75 per cent, alcohol, to which a few drops of corrosive sublimate have been added. Their presence is also readily detected by compressing a drop or two of the caecal contents between two microscope-slides and holding them up to the light. The worms, if there be any, then appear as thin, white, transparent lines. AVe owe this method to Dr Wilson. T. pergracilis is an extremely fine worm, measuring in the male on the average 6 to 8 mm., and in the female 8 to 10 mm. They are very narrow and hair-like, and, as a rule, whitish in colour, but sometimes have the tinge of blood when seen in a very thin layer on a slide through the microscope. They are very transparent, readily revealing their internal structure, and they are so soft that the pressure of a cover-slip almost always ruptures them. The cuticle is very clearly and definitely ringed, and the rings are so constituted that whilst the worm can easily work its way forward through a tissue, it would have difficulty in wriggling backward. The rings give the edge of the body a strongly serrated appearance like a saw. This is most marked a little way behind the head, and extends over about one-third the body length. There is no trace of longitudinal marking on the cuticle (vide PI. xxxni., Figs. 1 and 2). The genital bursa or expansion at the tail of the male is well formed, and opens by an oval opening with its long axis longitudinal. The bursa is supported by a number of ridges as an umbrella is by its ribs, and, using Looss's nomenclature, these are arranged in three groups. The members of each group arise from a common root and are recognisable, even when, as in the case of T. pergracilis, some of them run close to and parallel with members of another group. The three groups are : (1) Dorsal ; (2) Lateral ; (3) Ventral. The spicules in the male are very conspicuous and very difficult to describe. They are short, strongly chitinised, with thickened edges and a kind of haft or base at the anterior end ; and each spicule is hollowed something like a crumpled, withered, lanceolate leaf. Each spicule is provided with retractor and protractor muscles, 1 Vide vol. ii. Appendix D. VOL. I. O 210 THE GROUSE IN HEALTH AND IN DISEASE and when protracted they are divaricated. When in this extruded condition they form a cross, the left spicule projecting to the right and vice versa. Besides the spicules and between them, rather to the posterior end, lies the accessory or median piece, which Looss calls the " gubernaculum." It is best seen in profile, and has then somewhat the outline of a Turkish slipper. It also has muscles inserted into its ends. Near the base of each spicule is an oval clear vesicle ; but apparently the end of the spicule was outside and not inside the lumen of the vesicle. The head presents very little signs of differentiation. In some specimens with a one- twelfth objective three very minute lobes can be seen, but they are not visible in all cases, and their appearance may be due to some expansion of the mouth. The mouth is terminal and leads into a slightly bulb-like cavity which soon narrows into the thin capillary lumen of the alimentary canal. The oesophagus is more granular than the intestine, and separated from it by a very shallow groove ; its walls consist of flatly rounded cells with conspicuous nuclei. I could not detect any parts in the intestine ; it appears to be an undifferentiated tube running from mouth to anus, the lumen lined with chitin and the walls formed of granular cells with visible nuclei. No food was seen in the alimentary canal. Posteriorly the intestine widens into a spacious rectum, which just in front of the anus narrows again into a short, thin, terminal portion. The anus in the male opens into the genital bursa ; in the female it is a little distance in front of the end of the pointed tail, but relatively not so far forward as it is in the larva. Two cervical glands run about a fifth of the length of the body backwards, and end with rounded ends about the same level. In the male the testis begins about the level where these glands end. It consists of a single tube, the cells lining which give rise to the spermatozoa. Anteriorly the cells when squeezed out seem amoeboid, with rounded and very refringent nuclei. The hinder end of the testis is, however, crowded with spermatozoa shaped like little squat bottles, and in some specimens the genital bursa sheltered two clumps of these, looking as though they had escaped from the two vesiculse seminales. I saw nothing of excretory canals or their opening, and unless an ill-defined ring which surrounded the alimentary canal about one-twenty-fifth of the body- length from the anterior end be the nerve-ring, I saw nothing of the nervous .system. The ovaries are double. Each tube arises about the level or a little behind the "GROUSE DISEASE" STRONGYLOSIS 211 level of the hinder end of the cervical glands. One of them runs, with but slight undulations, straight to the "ovejector " which opens by the vagina, situated about one-sixth of the body-length from the hinder end, the other passes the vagina and reaches back almost to the anus ; it then doubles forward again and opens into the posterior "ovejector." The anterior end of each ovary contains undifferentiated protoplasm, but soon eggs begin to appear. At first these are very flattened, like a pile of coins, much broader than they are long ; then they become thicker, and, finally, three or four times longer than they are broad. The rounded nucleus is in every stage very conspicuous. It is impossible to say precisely where the ovary ceases and the oviduct begins. We find the long cylindrical cells rounding themselves off, and an egg shell beginning to appear. By this time fertilisation must have taken place, but I have not seen any spermatozoa in the oviduct. The oval cells usually lie at first with their long axis at right angles to the longitudinal axis of the oviduct ; then, when a little older, they lie obliquely, and, finally, they come to lie with their long axis parallel to that of the duct, in which position they are most readily swallowed by the "ovejector." The anterior and the posterior oviducts usually contain one, two, or three unsegmented ova ; then come some six to eight segmented eggs repre- senting as a rule the stages with two, four, eight, sixteen, thirty-two, sixty -four, and sometimes a hundred and twenty-eight blastomeres. One or two of these stages may be represented by two ova, but in any case the segmentation must be very rapid (vide PI. xxin., Fig. 3). The lower end of the oviduct is lined by what, in optical section, appear to be high columnar cells with very granular disintegrating borders. These seem to be secreting something. The walls of the oviduct pass suddenly into the " ovejector," which consists of three parts : () The most internal is somewhat funnel or trumpet- shaped, its wider mouth is continuous with the walls of the oviduct and is crenellated ; the funnel is richly supplied with both longitudinal and circular fibres ; not infrequently it contains an egg. (b) The second chamber of the "ovejector" is spherical, very transparent, and is marked by the presence of a large number of radiating muscle-fibres running from the periphery to the limits of the lumen. The contraction of these fibres would enlarge the lumen and suck the egg on. (c) The third chamber of the " ovejector" is thin-walled, with a chitinous lining. It frequently shelters an egg. At its outer end it narrows, and uniting with the similar narrow end of its fellow it forms an extremely short vagina which opens to the exterior by a longitudinal slit, the edges of which are also crenellated (vide PI. xxxin. Fig. 2). 212 THE GROUSE IN HEALTH AND IN DISEASE The ova are laid in the fluid contents of the host's cseca in which they are frequently found floating. We have found developing ova in the cseca of a young Grouse chick of seven to ten days of age from Auchentorlie, Dumbartonshire. Apparently the cseca are the chief centres of absorption of the digested food ; they contain none of the cellulose skeletons of vegetable cells so common in the intestine, and none of the masses of cast epithelium which make up so large a proportion of the flocculent masses in the duodenum. The eggs may develop further inside the caecum, though as yet we have not found an egg containing an embryo in its contents. A small pellet of the csecal contents, such as can be carried away on the point of a needle spread out under a cover-slip, will, in a well infected bird, show some twelve to twenty worms and one hundred to two hundred eggs in the field of a two-thirds inch Ross's objective with a No. 2 eyepiece. Allied In his Memoir on the genus Trichostrongylus, Looss enumerates species. tne f u ow i n g f our species : (1) T. RETORT^EFORMIS (Zeder), 1800. From the duodenum and exceptionally from the stomach of Lepus timidus and Lepus cuniculus (when undomesticated). Railliet says it coexists with Strongylus strigosus, and helps to give rise to a per- nicious anaemia. It develops directly without intermediate host. (2) T. INSTABILIS (Railliei), 1893. Syn. T. subtilis Looss, 1905. From the duodenum and exceptionally from the stomach of Ovis aries, Ovis laticauda, Antilope dorcas, Camelus dromedarius (Egypt), Papio (Cynocephalus) hama- dryas (North Africa), and occasionally in Man (Egypt and Japan). Railliet states that this species, together with Hcemonchus contortus, lives in the duodenum of sheep which succumb to pernicious anaemia. (3) T. PROBOLURUS (Railliet), 1896. From the duodenum of Ovis aries, Ovis laticauda, Antilope dorcas, and occasionally of Man (Egypt), and Camelus dromedarius (? Paris and Egypt). (4) T. VIBRINUS Looss, 1905. From the duodenum of Ovis aries, Ovis laticauda, occasionally from Camelus dromedarius and Man (Egypt). Looss regards this as a rare species. To these must be probably added : (5) T. TENUIS (Eberth), 1861. Syn. S. tennis (Mehlis) Eberth, 1861. From the caecum of the goose, Anser cinerea, and (6) T. NODULAXIS (Rud.), 1809. Syn. S. nodularis(Rud.), 1809. Syn. A scaris mucronata Frohlich, 1791; S. anseris Zeder, 1800; S. nodulosus Rud., 1803; crispinus Molin, 1850. From the mucous and muscular coats of the stomach and "GROUSE DISEASE" STRONGYLOSIS 213 duodenum of various species of the family Anatidoe. They are said to be very fatal to young geese. (7) T. PERGRACILIS (Cobbold), 1873. Syn. S. pergracilis Cobbold, 1873. From the caecum of Layopus scoticus. (8) T. QUADRIRADIATUS (Stevenson), 1904. Syn, S. quadriradiatus Stevenson. From the intestines of pigeons. (9) T. EXTENUATUS (Railliet), 1898. Syn. S. gracilis M'Fadyean, 1897, not Leuckart, 1842. This form occurs in the fourth stomach of cattle in England, and in cattle, sheep, and goats in the United States. 1 (10) T. OAPRICOLA Ransom, 1907. From goats and sheep in the United States. It is noticeable that this genus of parasite occurs only in vegetable feeders, and that, whereas it lives always in the stomach or the duodenum of mammals, it chiefly inhabits the cseca of birds. PARASITES OF TRICHOSTRONGYLUS PERGRACILIS (Cobbold). In a female specimen two amoeboid organisms were making their way along the body-cavity in the region of the "ovejector." Each was throwing out rounded pseudopodia, and the distinction between the granular endosarc and the glassy ectosarc was very sharp. Another specimen had some refringent bodies, in shape like short rows of yeast-cells or fungi-spores, lying in the body-cavity. The life-history of Trichostrongylus pergracilis (Cobbold) is described by Dr Leiper in Part II. of this chapter. (ii.) SYNGAUUS TRACHEALIS (Von Sieb). The Red or Forked- Worm. We have found this common pest of the fowl-yard and pheasant-coop but twice in the Grouse. Probably the free and un confined life of the Grouse, together with the comparative paucity of earthworms on the moors, protects Grouse from the " gapes," as the disease caused by the forked - worm is called. Earth- worms abound in Scotland in the cultivated lands, pastures, and woodlands, and occur even on the tops of mountains. Mr Wm. Evans tells me he has a list of seventeen species of the Lumbricidse taken north of the Tweed, but they are practically absent from the peat-moors, where heather, Grouse, and humic 1 B. H. Ransom, U.S. Department of Agriculture, Bureau Animal Industry, Circular 116, 1907. 214 THE GROUSE IN HEALTH AND IN DISEASE acid are most abundant. Some moors, however, such as those on the Pentlands, include patches of land in which worms flourish. Still there seems no reason at present to incriminate the forked worm of causing any trouble to Grouse. One of our cases was a young bird from Argyllshire. (II.) Family Trichotrachelidse. (iii.) TRICHOSOMA LONGICOLLE (Rud.). Synonyms : Calodium caudinflatum Molin. Trichosoma gallinum Kow. Trichosoma caudinflatum Kow. HISTORY. This genus, first named and described by Rudolphi, 1 is also described by Dujardin 2 from various species of gallinaceous birds. He gives a list of the earlier and ill-defined synonyms. The species is also mentioned by Diesing 3 under the same name. It is recorded by Molin 4 under the name Calodium caudinflatum, the name referring to the swollen tail of the female, from the small intestine of the partridge and the quail. Eberth, 5 who gives the best account of the anatomy of the genus Trichosoma, gives a short description and a figure of a nematode under the same name, Trichosoma longicolle ; be draws attention to Dujardin's description of a funnel-like appendix to the vagina, and surmises that this is a prolapsed piece of the vagina ; this is undoubtedly the case in some of our specimens. Kowalevsky 6 mentions under the name Trichosoma gallinum what Dr von Liustow tells me is this species, and in a later paper 7 apparently describes and figures this under the name Trichosoma caudinjlatum. Unfortunately I have been unable to read this, as the paper is written in Polish. Railliet 8 considers that the Trichosoma longicolle described by Dujardin and Eberth does not agree with Rudolphi's description of his Trichosoma longicolle. He points out that Dujardin and Eberth's species occurs in the caecum of the fowl and of the guinea-fowl, and he renames this species Trichosoma retusum Raill., 1893. The length of this worm 1 C. A. Rudolphi, "Ento/oorum Synopsis." Berlin, 1819. 2 M. F. Dujardin, " Histoire Naturelle des Helminthes," p. 19. 3 C. M. Diesing, " Systema Helminthum," ii. p. 260, 1850-51. 4 R. Molin, " Sitzungsberichte derkaiserlichen Akademie der Wissenscliaften," xxxiii. p. 302. Wien, 1859 ; and " Denkschriften der kaiserlichen Akademie der Wissenschaften," xix. p. 330. Wien, 1861 ; also Mem. 1st Veneto, ix. p. 617, 1860. 6 0. J. Eberth, " Untersuchungen iiber Nematoden." Leipzig, 1863. M. Kowalevsky, "Bulletin international de TAcademie des Sciences de Cracovie," p. 280, 1894. " M. Kowalevsky, " Ro/prawy i Sprawozdania y. posiedzeii wyd/i lemii Umiejetnosci," xxxviii. p. 274. Krakow, 1901. A. Railliet, "Traitt de Zoologie Medicale et Agricole." Paris, 1895. "GROUSE DISEASE" STRONGYLOSIS 215 is 13 mm. in the male, 19 mm. in the female. Rudolphi's worms which may belong to more than one species vary from 39 to 80 mm., and have been described from Lyrurus (Tetrao) tetrix, the Black Grouse, Black-cock, or Grey-hen ; Tetrao urogallus, the Capercailzie ; Gallus gallinaceus, the Common Fowl ; Phasianus colchicus, the Common Pheasant ; Chrysolophus (Phasianus) pictus, the Golden Pheasant ; Perdix cinerea, the Common Partridge ; and Coturnix communis, the Common Quail. We first found specimens of T. longicolle in a Perthshire Grouse which was brought us in the morning we were leaving Blair Atholl for the south in the autumn of 1906. Having once seen it, however, it was soon observed again, though it occurs sparingly. It always lives in the duodenum, sometimes associated with the tapeworm Hymenolepis microps, and sometimes alone. The worms resemble short pieces of very fine white silk (vide PI. xxxm., Figs. 4 and 5). This species has two longitudinal rows of dark spots irregularly scattered in two lateral bands. Roughly speaking, there are five or six of the spots in a transverse row ; but they are not regularly arranged. The two bands arise anteriorly in the region of the oesophagus, and as they pass backward they become somewhat narrower, much more pronounced in appearance, and darker. Each spot corresponds with a unicellular gland, and the bands of these glands replace the ordinary nematode excretory system in the Trichotrachelidae, the family to which Trichosoma belongs. They have been best described by Jagerskiold. 1 Each cell opens by a minute straight duct which traverses the cuticle and forms what used to be called the rod-shaped body. The Trichosoma longicolle of Eberth 2 has a third or ventral band, and he mentions that Dujardin saw but one band in his specimens. The length of the specimens varied from 20 mm. in the male to 40 mm. in the female. The greatest breadth of the body was 4'5,, but in the neck-region it did not exceed 3 M, and tapered away to the anterior end, where the breadth was but 0'5M. The very regular large cells in the region of the neck, which are pierced by the oesophagus, are just under 3 M in width and are 12 M in length. In the young specimens these cylindrical cells with flat ends, lying like a lot of pillars end to end, are not cut up into a series of segments, which gives a scalloped outline to the cells of the adult when seen in profile. But later a number of circular constrictions arise, and these divide each cell into a series of ten or twelve areas " Kongliga Svenska Vetenskaps-Akademiens Handlingar," xxxv. ii., 1901. 2 " Untersuchungen iiber Nematoden." Leipzig, 1863. 216 THE GEOUSB IN HEALTH AND IN DISEASE upon each side, and the whole cell has the appearance of being built up of two rows of rounded bricks lying side by side in a double pile. The nucleus remains large, oval, and conspicuous. At the end of each cell there is usually a dark granulation which serves very clearly to define their limits. The lumen of the oesophagus which pierces these peculiar cells is very minute, and is lined with a definite chitinous tube. The " cellular body," as the aggregate of the cesophageal cells is sometimes called, ends abruptly, about one-fifth the body- length from the anterior end. Here the oesophagus passes quite abruptly into the capacious intestine with its many-celled walls. Just at this point, and tucked away in the angle formed by the minute oesophagus widening into the broad intestine, are a couple of glands, probably the homologues of the cervical glands of other nematodes. The intestine continues to the hinder end of the body with no change ; it is somewhat difficult to distinguish, as it is just about the same brown colour as the lateral lines. The posterior end of the female is truncated, and the anus is at the ventral side of the abruptly terminated body. The ovary is a single tube which anteriorly contains undifferentiated eggs. These gradually attain a definite and somewhat irregular outline. Posteriorly the ovary opens into a spacious uterus, in which the ova are oval, with a distinct vitelline membrane. The uterus is broad, and serves, with its contents, to conceal the other organs of the body. Posteriorly, where the body is wide, the ova are irregularly crowded together ; there may be as many as five or six ova in a transverse row. Further, towards the head the ova acquire their characteristic egg- shell with two bright spots at each end. They closely resemble the eggs of Trichocephalus trichiurus (dispar). About halfway along the body the diameter lessens as we pass forward, and after a certain space the uterus is narrowed and only permits a couple of eggs to be abreast, and finally the eggs are reduced to a single row. The uterus opens by a vagina which is situated a little way behind the end of the "cellular body," i.e., just behind the anterior end of the intestine. The uterus or vagina is usually prolapsed and forms a bell-like structure, one edge of which usually has a clear oval vesicle in its walls. Through this bell-shaped structure the eggs pass out. The male is markedly smaller than the female. Its average length is about 25 mm. and its width throughout does not surpass the anterior end of the female's body. The testis is a single tube which opens posteriorly. At the tail end the male has a pair of cuticular folds or flanges, possibly representing a genital bursa. There is a single spicule, very long, and in many cases only perhaps protruded for a "GROUSE DISEASE "-STRONGYLOSIS 217 fourth or fifth of its whole length. It is described as having a sheath ; but in the specimens we have seen this was not apparent probably it was retracted. The males are very much rarer than the females in fact, we examined a consider- able number of specimens without finding a single male : probably they occur in about the proportion of one to seven or ten females. We have occasionally found a very long, thin larva in the duodenum, which we take to be the larva of the Trichosome. The eggs appear to undergo no segmentation in the body of the worm, and, in fact, we have not yet seen an egg of Trichosoma longicolle segmenting. In one Grouse from Ross-shire small embryos of some nematode were found in the small intestine. It is possible that these are the young of T. longicolle, but they show no trace of division into neck and body. It is also possible that they are the larvae of Trichostrongylus pergracilis ; but they differ in size and shape from those young of this species which we have hatched out and found free. The Grouse in which they were found have been feeding on corn, and I am rather inclined to believe that these larvae are the young forms of Tylenchus tritici which causes the well- known "corn-cockle." Trichosoma longicolle occurs only in the duodenum, often associated with the species of Hymenolepis which inhabits this part of the alimentary canal. They are surrounded by epithelial cells, singly and in clumps, and of many sizes and shapes, which have been shed in immense numbers from the wall of the duodenum. These may have been detached by post-mortem digestion. These worms have been found in 13 '6 per cent, of the birds examined ; but it must not be forgotten that they are most inconspicuous and easily overlooked. They have been found in Grouse from Montgomeryshire and Yorkshire, as far north as Ross-shire, and at all seasons. They do not occur in large numbers, and their pathological effect seems small ; still we must not forget that their near ally, the human parasite Trichocephalus trichiurus (dispar), is one cause of peritonitis and appendicitis in man. However the nematode makes its way into the chick, it must, like the Trichostrongylus, grow very rapidly. We have found specimens in a Grouse- chick of fourteen days in age. (III.) Family Ascaridse. (iv.) HETERAKIS PAPILLOSA (Bloch). Stossich * mentions this round- worm, under the synonym of H. vesicularis Frohl, as occurring in the Grouse. It is a very common parasite in poultry and 1 " Glasnikhrvatskoga naravoslovnoga druztva," Societal hiatorico-naturalis Croatica, p. 284, Zagreb, 1887. 218 THE GROUSE IN HEALTH AND IN DISEASE pheasants. It occurred in the hand-reared birds at Frimley, and Dr Cobbett and Dr Graham-Smith have found twenty-three in one caecum and ten in the other in a Grouse from Abbeystead which was free from T. pergracilis, and one in each ceecum of a Grouse from Longtown, Cumberland, which had one hundred and eight T. pergracilis in one caecum and one hundred and twenty-seven in the other, and the same number similarly distributed in a bird from Bolton Abbey, which had three thousand one hundred and eighteen T. pergracilis in one csecum and two thousand eight hundred and seventy-seven in the other. (IV.) Family Filariidae. (v.) FILARIA SMITH; (Sambou.) Dr Sambon * has described a microfilaria or larval form of some species of Filaria in the blood of Grouse. The adult forms of such larvae usually live in the lymphatics and subcutaneous tissues ; their larvae pass into the blood, and are conveyed to new hosts by some blood-sucking insects. PART II. ON THE DEVELOPMENT AND BIONOMICS OF TRICHOSTRONGYLUS PERGRACILIS By Dr Robert T. Leiper In view of conclusive evidence accumulated by the Inquiry regarding the constant presence of a small threadworm Trichostrongylus pergracilis in the caeca of nearly all sick adult Grouse, it became a matter of importance to study in some detail the life-history of this parasite with a view to determining the manner in which it is reproduced and disseminated, the mode of infection of healthy birds and, if possible, to obtain experimentally the symptoms of " Grouse Disease" under artificial conditions. In order also to have some reasonable basis of fact upon which to establish preventive and curative measures, a knowledge of the conditions favourable to and inimical to the growth of the parasite at its various stages of development became necessary. The present section deals with the results of an inquiry into these problems. The parasites are exceedingly fine hair-like worms of about one-third of an inch in length, and of a pale pink colour, but of such transparency as to be almost 1 See "Journal Tropical Medicine and Hygiene," x, p. 304, 1907. Filaria smithi cannot, however, stand as the name is preoccupied by Cobbold's species, Filaria smithii, from the elephant. Transactions of the Linnixan Society of London, 2nd. "GROUSE DISEASE " STRONGYLOSIS 219 invisible to the naked eye. They live in the caecal portions only of the intestine of the Grouse. The sexually mature females give rise to Deyelo I FIG. 16. Morulte of eggs. their progeny as eggs, which undergo a certain degree of develop- ment while still within the body of the worm. By the time they are body of the Grouse. laid the egg content has become subdivided into a large number of cells, forming what is technically known as the morula (Fig. 16). As morulce these eggs pass into and mix with the contents of the ceeca, all further development thereupon ceasing. This suspen- sion of development appears to depend upon a lack of some necessary stimulant in the caecal contents, for the eggs may be found alive and at the same stage not only several days, but even so long as a month after the death of the bird. In nature the caeca are evacuated periodically, and the ova thus pass out of the body with the soft portion of the bird's dropping. In one or two cases where a portion of the csecal contents had passed into the rectum, and had there become diluted somewhat by the fluid from the great intestine, eggs were found to have progressed to the formation of an embryo while within the body of a dead bird ; but such a condition is obviously abnormal, and does not invalidate the general conclusion that the eggs of this parasite require to pass out of the body of the bird before they are able to continue their growth, and that, in consequence, the parasites within the body cannot increase in number by sexual multiplication. Each and every parasite found within the body of the Grouse must therefore have actually entered it from the outside. We shall see later that this explains the apparent anomaly that whereas practically all Grouse are infected with Trichostrongylus only some suffer from the disease. The egg, when newly passed, measures 0'075 mm. by 0'046 mm. and contains a morula composed of about sixty-four cells. If a freshly passed csecal dropping be isolated and kept uncontaminated no further development will take place in the ova contained in it. A fungus will gradually grow upon it, and owing to this and bacterial con- tamination the eggs eventually die. If the dropping be exposed to the drying influence of sun and wind, as on the moors during the body - summer, it becomes caked and dry, and the eggs die. If, on the other hand, csecal dropping be spread out in such a way as to admit of the whole becoming 220 THE GROUSE IN HEALTH AND IN DISEASE oxygenated by the atmosphere, and it be also slightly moistened, development will proceed, its rapidity increasing with the temperature. Cultural ^ or t ne experimental study of the extra-corporeal development the methods, following method was found most reliable. Petri dishes, as used in -bacteriological research, of a diameter of about 4 inches, were employed in pairs. Into the upper dish was placed a closely fitting piece of thick blotting paper, which was thoroughly moistened with water. The inside of the lower dish was smeared uniformly with a very thin layer of csecal dropping or csecal content taken direct from a dead bird. Several drops of water were then added and mixed into the viscid layer by means of a glass microscopical slide so as to produce a glairy mixture that would but slowly slide off the Petri dish when it was held almost upright. The layer of faeces should be sufficiently thin to allow of an examination under the microscope with a two-thirds inch lens. The upper Petri dish was then placed over the lower dish, forming a close chamber, the atmosphere of which quickly became saturated with water vapour. From time to time the Petri dish was opened and a small quantity of faeces removed on a platinum wire for microscopical examination, or the lower part was placed upon the stage of the microscope and directly observed. A similar method, and one which permitted the study of the various stages of development in a small number of eggs, was the use of hanging drop dishes. If the former of these two methods has been adopted, in the course of twelve hours the colour of the culture in the Petri dishes should have changed from a greenish yellow to a reddish brown, and a sickly sweetish odour, similar to that found in lactic acid fermentation, should have become distinctly appreciable. Otherwise experience teaches that putrefactive processes will almost certainly set in and lead to the destruction of the eggs and worms in the culture. After the eggs have hatched, and when minute worms are seen wriggling through the culture, it will be found advantageous to leave the Petri dish open for several hours in order to allow of the evaporation of some of the water, and the culture to acquire more consistency. A larger amount of water appears to be necessary for the growth of the young parasite previous to hatching than afterwards. Indeed we shall see later that a certain amount of consistence appears to be absolutely necessary for the full growth of the young worm. In the culture made by the above method the egg mass continues rapidly " GROUSE DISEASE " STRONGYLOSIS 221 to segment until the resulting cells are exceedingly small. The mass becomes somewhat flattened, and a slight dimple appears at one border of the oval disc (Fig. 17). This is the first step towards the formation of the cylindrical body of the young embryo. . By the gradual deepen ovum - ing of this dimple the egg mass acquires a tadpole - like appearance, the anterior end being, thus early, easily distinguished from the posterior end of the body. The anterior portion soon exhibits a central depression, which indicates the commencing for- mation of the mouth (Fig. 18). As the lateral dimple continues to deepen the body mass elongates to such an extent as to become folded upon this two or three times, in order to become accommodated within the shell (Fig. 19). The alimentary canal meanwhile has gradually been developing, so that by the time the embryo attains a cylindrical form the canal is found to extend throughout the body as a distinct cell-walled tube (Figs. 20, 21). During the whole of this period the embryo remains quiescent, but about an hour or so before it leaves the egg-shell it commences to exhibit a certain amount of movement. This movement gradually increases FlG - 17 - FlG - l8 - Developing ova of T. pergracilis. FIG. 19. FIG. 20. Formation of the larva of T. pergracilis. FIG. 21. in extent and vigour, until it ultimately overtaxes the resistance of the egg shell, which suddenly ruptures. The success or failure of these efforts on the 222 THE GROUSE IN HEALTH AND IN DISEASE part of the young worm appears to depend on the amount of water which is imbibed from the outside, for if only such an amount of water be added to the culture as is absolutely necessary to set the process of development in motion, and the culture be then allowed to dry somewhat, it will be found that the embryo is incapable of rupturing the egg shell. A slight collapse of the egg shell, owing to an insufficiency of water, causes the death of the embryo at any period of its growth. Hatching usually takes place in from thirty-six to forty- eight hours after the egg passes out of the bird ; but in summer it may be delayed for even as long as a month. When the embryo is hatched there seems little purpose in its early movements. The cuticle, at first irregularly crinkled, gradually smoothens as the parasite becomes saturated with water. The movements now appear to gain in purpose, and very soon the little worm is actively moving about, obviously in search of food. When newly hatched, the embryo measures 0'36 mm. in length, and O'Ol 5 mm. in greatest thickness (Fig. 22). The cuticle shows no regular striation. The body Anatomi- * s cylindrical, tapering to a slender pointed tail in the last O'l of a acter-s^f mm. of its length. Anteriorly it maintains an almost uniform diameter theembryo. ^ w ity n Q.Q5 o f ^ e mou th, when it shows a slight and gradual narrow- ing. The anterior extremity ends bluntly, and has a diameter of "007 5 mm., presenting at its summit the small rounded opening of the mouth capsule. At 0'06 mm. from the tail the anal pore opens with but little external indication. Alimentary Canal. Two faint parallel lines are seen running inwards for a distance of O'Ol mm. from the oral pore. These are the walls of a cylindrical mouth capsule, which later, with the growth of the worm, become much more thickened and obvious. The oesophagus measures O'l mm. in total length, and is divided into two portions. The anterior two-thirds is cigar-shaped, uniting by a narrow neck with the posterior one-sixth which becomes bulbous. Surrounding this narrow neck are a number of large refractile cells, forming the nerve ring of the central nervous system. The oesophageal portion of the gut discharges into a long chyle intestine. The epithelial cells of its wall lie at first almost in touch, and the lumen is visible merely as a long, fine, wavy streak passing along the centre of the body. The rectum is short, O'Ol mm. in length, and is cuticular. Upon the success of the embryo in obtaining a plentiful supply of food depends almost wholly its future growth. If a "freshly hatched embryo be " GROUSE DISEASE " STEONGYLOSIS 223 Fios. 22 AND 23. Newly hatched embryos of T. pergracilis, highly magnified. 224 THE GROUSE IN HEALTH AND IN DISEASE transferred to plain water it will live for several days, but show no growth or further development. Evidently there is only a sufficiency of reserve sub- stance within the ovum to develop the embryo to the time of hatchino-. When there is enough food, but the medium is very aqueous, the worm requires to exert itself to a much greater extent in order to entrap small solid The first moult or particles of food into its rigid and chitinous mouth capsule. If, however, the culture is of such consistency that the embryo is able, by burrowing its way through the faecal matter, to force this into its mouth capsule, there follows a very rapid growth in size and early differentiation of tissue, even when there is a marked lack of oxygen. Under these favourable conditions of food supply an embryo increases in size to such an extent that on the fourth or fifth day from the commencement of the culture it is obliged to shed its cuticular covering. At this time thousands of very delicate sheaths may be found floating in the culture for a few hours ; but they very rapidly disappear. The embryo now measures about 0'46 mm. in length, the oesophagus 0'12 mm., the anus line 0'08 mm. from the tip of the tail (Fig. 23). An excretory pore is to be seen 0'09 mm. from the anterior end of the body, and at 0'24 mm. from the anterior end there is now visible a small clear globule O'OOS mm. in diameter lying on the ventral surface between the body wall and the wall of the chyle intestine. This is the rudiment of the future genital system. A marked difference is now noticeable in the chyle intestine. Three large well - developed valves are seen governing the entrance to it from the oesophagus. Its lumen is widely dilated, O'Ol mm. in diameter, and is filled with ingested fseces. The cells of the gut wall are flattened and very finely granular. No gross structural alterations accompany this first moult or ecdysis, but during the succeeding three or four days certain changes within the body of the worm gradually become evident. The cylindrical mouth capsule (Fig. 24) slowly loses its clear cut border and appears to be undergoing absorption, and its lumen decreases (Fig. 25). At Themeta- the same time the oesophagus lengthens, the bulbous posterior portion morphosis. b ecomes pyriform, and later merges into the anterior portion, but so gradually as to be only definable with difficulty. The cuticular lining of the whole oesophagus, and the marked triradiate lining of the cesophageal bulb (Fig. 24) become resolved into a simple thin cuticular covering (Figs. 25, 26). The walls of the intestine, which have gradually increased in size, become more "GKOUSE DISEASE" STRONGYLOSIS 225 clearly defined, and now appear as cylindrical turgid cells distended with large globules of highly refractile substance, giving the larva a characteristic appear- ance by which it can be readily distinguished from free-living nematodes (Fig. 26). The whole body appears to have slightly narrowed during the process of metamorphosis, by the conclusion of which the larva has become changed into a slender actively moving worm, with a simple elongated oesophagus without mouth capsule (Figs. 26, 28). Accompanying the metamorphosis in structure is a marked change in habits, for instead of burrowing into the denser portions of the food FIG. 24. FIG. 27. FIG. 25. FIG. 26. Changes in T. pergracilis during ecdysis and encystment. these metamorphosed forms now rush about with great rapidity, and either wriggle into the patches of open water or make their way on to the actual surface of the culture, and may be seen standing out in numbers into the moist atmosphere above, forming a kind of hoar frost on the surface of the faeces apparently in search of oxygen. Those larvae, which are fortunate enough to be near the edge of the culture, ascend in the condensed water on the sides of the Petri dish and make their way on to the upper part, eventually reaching the blotting paper. VOL. i. p 226 THE GROUSE IN HEALTH AND IN DISEASE Others will crawl out of the thin edge of the culture medium and become stranded on the dry glass. This metamorphosis takes place between the eighth and sixteenth day from the commencement of the culture, the difference in time depending almost entirely on the temperature at which the culture is kept. If the blotting paper be now removed, and the upper part of the Petri dish be put aside, so that the moisture on its inner surface, which contains The second tae actively wriggling metamorphosed larvae, be allowed to evaporate encyst- slowly, it will be noticed that as the water disappears the move- ment." ments of the larvae gradually diminish and eventually entirely cease, so that ultimately the larvae lie sometimes making irregular figures like notes of interrogation, sometimes coiled up like a watch spring (Fig. 29). If drying proceeds sufficiently slowly it would be found on examining the dish with a hand lens, that when all traces of moisture have disappeared the little coiled larvae stand out as turgid, glistening streaks. They seem to be capable in this condition of retaining a certain amount of moisture within their thick resistant cuticle for several days, and to make up for any loss of fluid by evaporation by slowly retracting the body from either end and of detaching themselves from their cuticular skin (Figs. 26, 27, 30). This retraction may go on to such an extent that if one suddenly adds water once more to a Petri dish containing such dried forms the little worms are found enclosed in long sheaths that extend much beyond each end, recalling the sheathed embryos of filaria seen occasionally in the blood of man. This second formation of a sheath, or as it is sometimes called, the " encystment," is the last stage of the development of the larvae outside the body (Fig. 30). It appears to be a necessary preliminary to the attainment of infectivity, and once this stage is reached the larvae can remain alive without food or further growth for weeks. The larva does not shed this second sheath until it reaches the alimentary canal of the Grouse. There are thus two moults in the extra-corporeal development. The first is completed prior to metamorphosis ; the second, subsequent thereto, is not completed during the non-parasitic period. So much then for artificial experiments. The following details of an experiment made during August 1909 serve to illustrate what actually becomes of the hatched worms under Larval . 1-1 migrations natural conditions upon the moors. A culture made m the manner described above was taken to a small village, on the coast of the Bay of Cardigan, where no Grouse lived or had been known to exist for many years. " GROUSE DISEASE " STRONGYLOSIS 227 Some young plants of bell heather were sought, and eventually two or three small suitable plants were detached uninjured from crevices in rocks. These were planted in a Petri dish, and the dish was half filled with water so as to cover the roots. The plants were then set aside. A week later they were found to have survived the transplantation, and 'to have commenced to grow FIG. 28. FIG. 29. Larvoe forms of T. pergracilis \ FIG. 30. Encysted larvae of T. pergracilis. under the new conditions. As the weather was showery the plants and dishes were left out in the open, and for two or three days in succession the raindrops hanging from the tips of the heather were microscopically examined. They were found to be almost free of life. On one occasion, however, a small free living nematode was found. Although slightly resembling the larvae of Trichostrongylus pergracilis it was readily dis- tinguished from them by its microscopical characters. 228 THE GROUSE IN HEALTH AND IN DISEASE Immediately after one of these periodical examinations, the culture of Trichostrongylus pergracilis, in which the majority of the larvse had just under- gone metamorphosis, was poured into the water round the roots of one of the experimental plants. The plant was left out in a typical " Scotch mist " for a couple of hours. At the end of that time raindrops were again taken from the highest tips of the heather, which were about 3J inches above the surface of the water, and they were found to be literally swarming with the actively wriggling metamorphosed larvse of Trichostrongylus pergracilis. These larvse had ascended the wet stems and leaves of heather against the current of water that was trickling down towards the roots. Their intense activity was doubtless due to the large amount of oxygen present in the fresh rain. The plant was then taken from the Petri dish and placed in a cardboard box, which was sealed down. A month later the box was opened. The heather was found to be alive still and growing, but very dry. The tips of the shoots from which the raindrops had been taken were cut off and soaked in little watch glasses of fresh water, and in the course of half an hour there wriggled out from the crevices of the leaves of the heather a considerable number of larvae, showing at either end the long collapsed parts of the sheath which as we have already seen are characteristic of the larvse that have undergone drying under artificial conditions. The intestine showed the characteristic refractile appearance already noted. The following synopsis of the life-history of this parasite may be of interest Synopsis as summarising the order and minimal duration of the various stages history. in the life-cycle. April 1. Egg in morula stage passes out of Grouse. ,, 3. Larva hatches out and lives in dropping or in moist earth. ,, 5. First moult or ecdysis. ,, 8. Metamorphosis, larva now in actively migrating form. ,, 9 (or after). Larva ascends to tips of heather; if there is no mist,, rain, or dew the ascent will be postponed. ,, 10 (or after). Encystment or drying; this represents the first stage of the second moult an indefinite interval may intervene here. 10. Larva swallowed by Grouse, and completes second moult. 11. Reaches ceeca of Grouse. "GROUSE DISEASE" STRONGYLOSIS 229 April 13. Completes his hypothetical third and fourth moults, thereafter become adult and sexually productive. ,, 13. Pairs as soon as adult stage is reached. ,, 14. Lays eggs in caeca. ,, 15. Eggs pass out of Grouse. Thus the exact mode by which the worms attain to the most favourable conditions for infecting the Grouse had been determined, for the young growing tips of heather are those most sought after by the birds. It remained to be seen whether the administration of these metamorphosed encysted larvse to healthy Grouse would result in the actual production of Trichostrongylosis. It is related elsewhere in the Report that the administration of eggs and embryos of the Trichostrongylus pergracilis and of centrifugalised wash- ings of heather from the moors to healthy uninfected Grouse had given uniformly negative results. From the observations described mental J induction above the explanation of these failures becomes very evident. The of Tricho- strongylosis. eggs and embryos of the parasite require to undergo certain essential developmental changes for a period of almost a fortnight's duration before they acquire the power of infection when swallowed by Grouse. The forms got from the heather were undoubtedly non - parasitic nematodes and their young, for these bear a general resemblance to the unmetamorphosed embryos of Trichostrongylus pergracilis many of them having a very similar type of mouth capsule. Moreover, the embryos of Trichostrongylus pergracilis do not acquire their migratory habit until they have become metamorphosed, and there- fore do not ascend the heather until they have entirely lost their oral capsule. Until the above described experiments were successfully concluded the characters of the metamorphosed larvse were quite unknown, and therefore it was impossible that they should have been recognised in washings of heather. Owing to the fact that the deliberate administration of Grouse faeces to healthy Grouse for the purpose of scientific observation is considered to be a form of vivisection (accidental infection occurs continually on the moors), and owing to the desirability that the various experiments of this character should be carried out by one member only of the Committee, the cultures were handed over to Dr Wilson for the purpose of administration to hand-reared Grouse at the Frimley experimental station. 230 THE GROUSE IN HEALTH AND IN DISEASE On June 19th, 1909, the culture which had just undergone metamorphosis, and which was therefore in the active migrating stage, was administered to an adult male bird one year old. The droppings of this bird were entirely free from Trichostrongylus ova when the experiment was begun. An examination of the faeces on the successive days showed that no infection had taken place. By June 26th the culture had undergone further development changes, and showed a large number of encysted forms. A dose was again administered by Dr Wilson, and some four days later ova of Trichostrongylus pergracilis were found in the droppings. The number of ova increased on successive days. On July 3rd a further dose of the same culture, now thirty days old, was adminis- tered. The bird died five days later, showing distinct loss in weight, the presence of a large quantity of chalky fluid in the rectum, and the caecal contents red with blood. From the post-ftwrtem, examination I came to the conclusion that the bird had been killed by the passage of some of the last culture into the lungs, for there was considerable pneumonia, and quantities of the culture were found in the fine tubules. This first experiment was therefore not wholly conclusive as regards the actual induction of Trichostrongylosis by the administration of encysted metamorphosed Trichostrongylus pergracilis larvae. It served to establish, however, that these larvse can reach the caeca of the Grouse, attain their adult condition, and become sexually productive in the very short space of four days. It also demonstrated that the sudden invasion of the cseca by a large number of Trichostrongylus pergracilis produced such a marked effect upon the mucous membrane as to fill the caeca with blood. In the second experiment made by Dr Wilson my culture was much older, and contained encysted forms. The doses were repeated periodically, with the result that in the course of two and a half months the bird fell in weight from 17 ounces to llf ounces. The caecal droppings were as full of Trichostrongylus pergracilis ova as those of a bird suffering from Tricho- strongylosis, and the bird itself showed a similar condition of progressive weak- ness and emaciation. The mucous membrane of the caeca was covered with Trichostrongylus pergracilis, but no evidence of extravasation of blood into the lumen of the caeca was found on. the death of the bird. Apparently that seen in the first case must have been associated in some way with the development of the parasite before reaching maturity. These two experiments indicated in so far as such a limited number may, "GROUSE DISEASE " STKONGYLOSIS 231 that this parasite in very large numbers has a marked pathogenic action upon Grouse, inducing loss of weight, progressive wasting, and in extreme cases, death. An examination of serial sections of the caeca in heavily infected Grouse shows that here and there the mucous membrane is penetrated by the anterior end of the worm ; but no evidence was obtained from the sections that such penetration led to the local invasion of the tissues by intestinal bacteria. The presence of eositiopkiUa in the blood as demonstrated by Dr Fantham indicates that J Signifi- certam substances secreted or excreted by the parasite pass into the canoe of circulation. 1 These, together with the loss of function of the caeca, owing to the extensive decortication of the epithelial lining by the worms, seem to me to sufficiently account for the resulting symptoms of the disease. The final invasion of the general circulation by bacteria represents the terminal phase in the progress of the disease, and not an essential factor in its causation. Most adult Grouse suffer also from a slight degree of Coccidiosis. This parasite to a much greater extent destroys the epithelial lining, so that were the common disease amongst Grouse primarily the result of invasion by intestinal bacteria, the coccidia should play a more important role than the Tticho- strongylus in the causation of the symptoms of " Grouse Disease." Yet it is well known that the droppings of adult birds may show evidence of considerable infection with coccidia without any symptoms of disease being apparent. Death of adults from Coccidiosis apparently only results from an intensity of infection not met with on the moors, but only in the hand-reared birds or birds experimentally infected. If it be accepted that Trichostrongylus pergracilis is the primary and essential factor in the production of the common form of "Grouse Disease" R eme di a i remedial measures must be directed either to the destruction of the measures - adult parasite within the bodies of the birds, or of the young forms during their stay outside the body. The impracticability of the former of these two methods is obvious. The birds are unapproachable, and are spread over a very wide area. Vermifuges or antihelminthics are expensive and more or less poisonous substances, the dosage of which has to be carefully estimated and controlled. The problem therefore resolves itself into that of destroying the eggs and larvae of the parasites during their stay outside the body. The destruction of the eggs or embryos by surface dressing with cheap 1 Vide chap. xiii. p. 316. 232 THE GROUSE IN HEALTH AND IN DISEASE chemical substances would appear at first sight to be a hopeful line of action, but the occurrence of the csecal droppings more or less all over the moor, and the enormous area requiring treatment, render any such methods futile. Moreover, as we have shown, the larvae after a brief period of development ascend the heather and can remain hidden in the crevices of the leaves, in a quiescent, invisible and living state for a prolonged period. The only conditions that could be inimical to these, the infective forms, would be atmospheric conditions Effect of f marked severity, possibly a prolonged frost or a prolonged drought, or destruction of the infected heather by fire or cutting. The effect of extreme cold has been tested by subjecting the metamorphosed larvae to freezing in the cold storage rooms at the Albert Dock for a period of a week. On being thawed out of the solid block of ice it has been found that they quickly regained their activity. Exposure to slow drying, on the other hand, under experimental conditions, results in the death of the encysted larvae. Effects of Death from lack of moisture must be continually taking place on the drought. moorS) although there may often be, even at the hottest parts of the day, an insensible transpiration from the growing plant, sufficient to maintain the life of the larvae by preventing desiccation. Burning ^,nd cutting appear to be the only practical means by which infected heather plants can be properly purged. To one more or less unaccustomed to the moors it is a matter of astonish- ment to notice what might be described as the extraordinarily insanitary condition of the Grouse's home. Nearly every square yard of moorland shows traces of faecal deposits, and forcibly directs attention to the fact that there is an unnatural over-population of the moors. When one remembers that practically all Grouse are infected with Trichostrongylus pergracitis, and that from every dropping thousands of Relation of potential parasites normally emerge, it becomes evident that the ^ greater the number of birds upon a given area, the greater in turn is. mus ^ De the, i n f ec ting capacity of the moor. But on most moors only a very small proportion of the heather is suitable for food for Grouse at certain times of the year, 1 and as the Grouse is a very heavy feeder it follows that the parts of the moor from which the food supply is derived are just those likely to be the most heavily contaminated with droppings. The number of birds on a moor should be correlated, not with the size of the moor but with the extent of the suitable food area thereon. The amount 1 Vide chap. iv. p. 71. "GROUSE DISEASE" STRONG YLOSIS 233 of stock on a large moor may seem very low proportionately to the whole area, but when estimated in proportion to the food area it may prove exceptionally high, and this means a high potential capacity for the pro- duction of Trichostrongylosis, whilst the entrance of a few bacteria or protozoan parasites into the body may suffice to cause serious diseases owing to the rapid multiplication of the original germs. In helminthic infections, as we have shown, the parasite cannot multiply inside the bird. Birds with few worms remain healthy. The progress of the disease is correlated with the actual number of parasites entering and surviving in the body. The more heavily infected the food, the more heavily infected does the bird become. The following facts connected with the growth of the parasite outside the body of the Grouse emerged from our Inquiry, viz. : (1) that moisture is necessary for the development of the egg ; (2) that a minimal tempera- ture of several degrees above freezing point is essential not only for facts .. , ,' - established. the development ol the egg, but also for the metamorphosis of the embryo ; (3) that the embryo ascends the heather only after metamorphosis. These facts afford us some explanation of the disease being a fatal one in the spring months. During the summer months many of the csecal droppings must be dried by the sun and wind shortly after they are passed, and the eggs thereby killed. The same agencies must also desiccate beyond revival a large number of the encysted larvse upon the heather. During the winter months, however, this loss does not occur. Owing to the low temperature and continual wet the eggs remain in a living but quiescent condition. Even if an occasional spell of warmer weather occurs, an,d the eggs develop into embryos, it would be necessary that such period of high temperature should continue for at least a fortnight to enable these embryos to become converted into active migrating larvae. The result probably is that there accumulates upon the moors during the whole winter vast numbers of undeveloped eggs and unmetamorphosed embryos. The low temperature does not kill them, but merely suspends their growth for the time being. At the spring-time the minimal temperature rises gradually to such a point as to allow the continuous development of the eggs and embryos to and through metamorphosis, with the result that at this period there presumably ascends the heather the accumulated result of feecal contamination during the winter months. The frequent rains and mists give the larvse ample opportunity to reach the topmost tips of the heather at this time. 234 THE GROUSE IN HEALTH AND IN DISEASE The rapid death of the eggs of Trichostrongylus pergracilis in feeces that have undergone temporary drying indicates that the drier the moor, the more efficacious will wind and sun prove as natural antagonists to " Grouse drainage, Disease." Again, as the infective forms of the parasite occur on the burning, and "food" heather, it is evident that the greater the amount of "food" cutting. i i heather in proportion to each bird, the less likely it is to become infected. As the periodical burning of heather increases eventually, not only the area of food heather, but at the same time destroys in the only effective way known the living parasites upon the area of heather burned, the policy of heather burning, advocated by other members of the Committee upon other grounds, receives additional support. The practicability and value of a periodical cutting of the heather requires further consideration by those acquainted with local conditions ; but, if practicable, such a measure should not only be a means of ridding large areas of the moor of infective material, and of bringing about a rapid increase in the " food " heather area, but might also be applicable to those parts of a moor and in those seasons of the year when burning is impossible. CHAPTER XI " GROUSE DISEASE" CONTINUED COCCIDIOSIS By Dr H. B. Fantham PART I. THE MORPHOLOGY AND LIFE HISTORY OF EIMERIA (Coccioiusr) AVIUM A SPOROZOON CAUSING A FATAL DISEASE AMONG YOUNG GROUSE * I. INTRODUCTION. The subject of this memoir is a microscopic, protozoal parasite, which infests the lining epithelium of the alimentary canal of Grouse. It belongs to the Coccidia, a group of parasitic protozoa, many of which are known to occur in the digestive tracts of both vertebrates and invertebrates. These minute organisms reproduce by means of resistant spores, and belong to that class of the protozoa known as .the Sporozoa. The Coccidia are of economic importance, inasmuch as they destroy the mucous membrane of the intestine of the host, thereby setting up enteritis which is accompanied by diarrhoea, and very often has a fatal effect upon the unfortunate animal harbouring the parasites, especially if the host be young. Such a disease termed Coccidiosis has long been known in rabbits, and is often fatal. Occasionally Coccidiosis occurs in man. The life-history of a coccidian parasite is complicated. There are two phases in the life-cycle : (1) a multiplica- tive phase within the cells of the gut-epithelium of the host, and (2) a reproductive phase leading, after a sexual act, to the formation of resistant spores adapted for life outside the body of the host. The spores so formed are the means of spreading the parasite, and lead to the infection of fresh hosts. The two phases were formerly considered to belong to separate parasites ; but the occurrence of alternation of generations in the life-cycle of Coccidia was first suggested by R. Pfeiffer in 1892, conjugation was discovered in Coccidia by Schaudiun and Siedlecki (1897), and the complete life-cycle was demonstrated with a wealth of morphological and cytological 1 Reprinted from the Proceedings of the Zoological Society of London, 1910. 235 236 THE GROUSE IN HEALTH AND IN DISEASE detail in the celebrated memoir of the late Dr Schaudinn (1900) on Eimeria (Coccidium) schubergi, parasitic in the gut of the centipede Lithobius forficatus. Coccidia have been recorded from most of the great groups of the metazoa, but very few coccidian life-histories have been investigated completely. Dr Leiper, while working on helminthiasis in Grouse in May 1909, noticed the occurrence of coccidian cysts in large numbers in the gut of many Grouse chicks, with concomitant enteritis, very often proving fatal. The coccidian cysts are oval, and at first sight might easily be mistaken for eggs of worms. Dr Leiper suggested that Coccidiosis was a factor in " Grouse Disease," especially in young birds. Early in June 1909 I spent some time on one of Lord Lovat's moors in Scotland for the purpose of investigating Coccidiosis in Grouse chicks. 1 Previously we had noticed, at various times, the occurrence of Coccidian cysts in adult Grouse, but not in large numbers. I have much pleasure in expressing my thanks to Lord Lovat, Dr A. E. Shipley, Dr E. A. Wilson, Dr Hammond Smith, and Dr Leiper for aiding my researches by procuring material for me, and to Professor Nuttall, in whose laboratory much of my work was done. I also availed myself of the services of the Secretary of the Committee, who placed me in communication with a large body of correspondents through whom I obtained further material to enable me to continue the investigation, and to whom my thanks are tendered. In this paper I wish to record my researches on the morphology and life-history of Eimeria avium, more especially as it occurs in the Grouse. I would point out that the length of time at my disposal for these researches has been limited, only one season being available to me for procuring material, and I have had several other investigations to consider during the period, so that I was not able to give undivided attention to the elucidation of the protozoa of Grouse. However, the complete life-cycle of Eimeria avium, responsible for the dwindling of Grouse broods in spring, is here set forth for the first time, so far as I am aware. II. THE GENERIC NAMES EIMERIA AND COCCIDIUM. Unfortunately, owing to the rule of priority, the generic name Coccidium (Leuckart, 1879) no longer holds, but is replaced by that of Eimeria (A. Schneider, 1875). I am in sympathy with Professor Minchin, when he writes in a recent review : " We regret to see the familiar generic name Coccidium replaced by Eimeria ; this is one of those many cases where, in our opinion, rebellion against 1 The number of Grouse chicks dying of Coccidiosis on the moors is not easily estimated, for the chicks die in the heather, and their tiny corpses are rarely found. "GROUSE DISEASE " COCCIDIOSIS 237 the law of priority in nomenclature is not only lawful but imperative " (Nature, March 3rd, 1910). It would save much confusion if the question of zoological nomenclature were settled by an international committee, 1 as has been suggested by many able workers. The Coccidia of birds were first recorded in fowls by Silvestrini and Rivolta (1873), under the name Psorospermium avium. Subsequently Railliet and Lucet (1891) recorded Coccidia from fowls, naming the parasite Coccidium tenellum. I have followed Doflein (1909) in naming the Coccidia of birds Eimeria avium. The coccidian parasites were obtained from Grouse chicks, and I have succeeded in transmitting the Coccidia of Grouse to fowl chicks and to young pigeons. III. METHODS. In this investigation of Coccidiosis both fresh and preserved materials were used. Samples of gut contents, taken from different regions, were examined fresh, and often these have been fixed wet with osmic or formalin vapour, and stained by Delafield's hsematoxylin or by Giemsa's stain. Such smears were sometimes useful for examining merozoites. Oocysts, because of the chitinoid and almost impenetrable character of their walls, had to be examined fresh. For preserved material, the best fixatives were found to be Schaudinn's fluid (corrosive-acetic-alcohol) and Bouin's fluid (picro-formol-acetic), to which a few drops of absolute alcohol were added. Schaudinn's fluid tends to shrink the tissues, while Bouin's fluid requires much washing out. Sections, 5/j. to 6/x thick, were made of the duodenum and cgecum of infected birds, these parts of the digestive tract being especially examined. The chief stains used were Delafield's heematoxylin (either alone or counterstained with orange G or eosin), which was found to be most useful, safranin and lichtgrlin, iron-heematoxylin (with or without Van Gieson's picro-fuchsin), and paracarmine. On the whole the heematoxylins proved of most service. On diluting some of the caecal contents or faeces of a Grouse chick suffering from Coccidiosis, and examining the preparation microscopically, numerous oval cysts are seen (PI. xxxvu., Figs. 61-66). Sometimes the cysts are also M orpho- seen in the small intestine just beyond the duodenum. These cysts may logy - have homogeneous contents, or, when older, may show four more or less well 1 The subject of zoological nomenclature is now (1911) being so considered. 238 THE GROUSE IN HEALTH AND IN DISEASE differentiated sporocysts within them (Figs. 67-70). Each sporocyst, if ingested by another Grouse, can develop two active, motile germs or sporozoites (Figs. 71-76). which can penetrate the intestinal epithelium especially of the duodenum and so begin a new infection. Though the oocysts and spores are the most obvious external manifestation of Coccidiosis, it is usual, and certainly more convenient, to begin the life-cycle of the Coccidium with the minute sporozoite (PI. xxxiv., Fig. 2), the agent whereby primary infection is brought about. The sporozoites are minute, falciform, or vermicular bodies (PI. xxxiv., Fig. 2) capable of fairly rapid movement, and possessing great penetrative powers. They measure from 7u to 10 in length. The ends of the sporozoite are rather Young growing pointed, the extremity that moves foremost being slightly more acuminate than the posterior end. The general body cytoplasm is more or less homo- geneous, exhibiting but very fine granulations. The nucleus has a definite rounded or oval contour. The chromatin is evenly distributed throughout the nucleus. When the sporozoites are liberated from the investing sporocyst (PI. XXXVIL, Figs. 74-76), by the action of the pancreatic juice of the Grouse, they are capable of active movement. The usual method of progression resembles that of the sporozoite or motile trophozoite of a gregarine. The organism moves forward with a slow gliding movement, the forward progression being facilitated by the secretion of a viscid proteid substance that rapidly hardens. On the smooth surface thus pro- vided the coccidian sporozoite glides forward. The track of the sporozoite, as shown by its trail, can be stained, and the organism then shows the gelatinous or proteid material issuing from near the posterior region of its body (PI. xxxiv., Fig. 2). During the gliding movement waves travel down the body of the sporo- zoite, recalling what is seen on a larger scale in the billowy undulations of the foot of a snail. On other occasions a more rapid movement of the sporozoite occurs. The two ends of the organism become approximated and then rapidly straightened, the effect being to propel the organism forwards much more quickly than when the gliding movement alone is used. The sporozoite thus makes its way to an epithelial cell of the duodenum and proceeds to penetrate the cell. As it forces its way inwards (PI. xxxiv., Figs. 3, 4), so the sporozoite curves on itself (Fig. 7) and becomes round and immobile (Figs. 5, 6, 8). The young, rounded parasite (Figs. 8-10) is now on the trophic phase of existence, and continues to grow for some time, feeding passively on the food-materials of the host-cell. During this period the parasite is called a trophozoite (Figs. 8-12). PLATE XXXIV. '- m 2. -**& HP-1^ 3. M ;#f; 4 5. ' 12. 13 - g ' 18 1 :/ c-i 19. 1 7. 20. ( ^F ' 21. H.B Fanlham del. EIMERIA (COCCIDIUM) AVIUM. (Schizogony.) 22. E.Wilson, Cambridge. "GROUSE DISEASE" COCCIDIOSIS 239 The nucleus of the trophozoite is approximately central in position, or sometimes to one side, and at first contains scattered granules of chromatin. It then becomes somewhat vesicular (Figs. 8-11), and gradually the chromatin collects into a central karyosome, lying within the nuclear sap (Fig. 12a). The position of the karyosome, however, is not always centrally fixed ; it may lie ^o -one side of the nucleus (Figs. 8, 10). The growth of the trophozoite naturally affects that of the host-cell. The protoplasm of the latter becomes more and more tenuous, great hypertrophy of the host-cell occurring. This condition is maintained for some time, and finally a limit is reached and atrophy sets in, the nucleus of the host-cell then appearing as a small, often crescentic mass (Figs. 10, 14) to one side of the film (Fig. 12) that represents the host-cell. A clear space often intervenes between the parasite and the enveloping epithelial film (Figs. 9, 11, 12). The trophozoite, having attained its full size (some lOyu to 12^ in diameter) within the host-cell, proceeds to divide, and the result of its division is to increase the number of parasites within the host. This stage in the existence of Eimeria aviutn is known as the schizont (agamont), and the method of multiplication is termed schizogony. The schizont (Fig. 12) is a more or less spherical parasite. At first it is uni- nucleate (Fig. 12a), but soon its nucleus begins to fragment (Fig. 126). The division of the nucleus of the schizont is of the nature of multiple fragmentation gchizo- rather than of a series of binary fissions of the nucleus and karyosome gony ' (Figs. 13-18). The parasite is very small, and it is not easy to follow the cytological details, even under the best and highest powers of magnification. Some of the portions of chromatin in multiple fragmentation may sometimes appear connected by thin strands (Fig. 13) for a short period, but the fragments soon travel to the periphery of the schizont. The small daughter masses of chromatin, at first homogeneous, gradually show differentiation, becoming minutely vesicular with a dot of chromatin usually to one side (Figs. 14-16), but occasionally central. Thus the nuclei of the future merozoites are forming their karyosomes early. The daughter nuclei having migrated to the periphery of the mother cell (Fig. 16), the cytoplasm of the schizont concentrates around them, forming small ovoid masses (Figs. 13, 19). The daughter-forms so produced are the merozoites (agametes) which measure 6^ to 10 M in length. They gradually acquire a vermiform shape, and arrange themselves around the remains of the protoplasm of the mother 240 THE GROUSE IN HEALTH AND IN DISEASE cell like the segments of an orange or the staves of a barrel (PI. xxxiv., Figs. 20-22 ; PI. xxxv., Figs. 23, 24). Owing to this method of grouping, the merozoites are said to be arranged "en barillet." The groups, when ripe, soon break up, and the individual merozoites are liberated. The movements of the merozoites, when free, resemble those of the sporozoites. The number of merozoites formed from a single schizont seems to vary. Eight to fourteen seem to be common numbers, but as many as twenty have been found. The merozoites finally are slightly curved vermicules (PL xxxv., Figs. 23, 24), possessing a nucleus which may be approximately central (PI. xxxiv., Figs. 20, 21) or somewhat towards one end (PI. xxxiv., Fig. 22 ; PI. xxxv., Fig. 23). The nucleus of the merozoite is small, and the presence of a karyosome is often not very evident, though there is a small granule of chromatin representing the karyosome usually to one side of the nucleus (Fig. 24). The ends of the merozoites are rather less pointed than those of the sporozoites, a feature that E. avium has in common with E. schubergi as described by Schaudinn. When the merozoites reach a new host-cell, they enter, become round, and proceed to grow as trophozoites in the same way as did their parent organism, and undergo later nuclear fragmentation in a similar manner. As the result of this, many more merozoites are produced, and as schizogony may be continued through several generations, the destruction of the gut-epithelium is very extensive (PI. xxxiv., Fig. 1). Towards the end of schizogony especially in the caecum relatively smaller schizonts with larger and fewer merozoites (Fig. 25), about five in number on the average, are produced. These larger merozoites appear to be formed near the end of infection, in company with large numbers of gametocytes, so far as evidence is available. These differences in the schizonts might be taken by some investigators to be indicative of difference in species in other words, that more than one species of Coccidium may occur in the gut of Grouse. I do not state that this is not so, but personally prefer the view that the differences in the schizonts and merozoites noted are reflexes of the condition of nutriment of the parasite. Wenyon (1907) has some interesting observations on the variations in the schizogony of E. falciformis in the mouse, and states that the variations are due to the nourish- ment available for the parasite. Again, the species found in the liver and gut of the rabbit (Coccidium oviforme and C. perforans) are now usually united into one species, Eimeria stiedce. PLATE XXXV. f 23. i t i 25. 1 29. ^P f t i^f;'- ;.- 33. HBFantham del. 34 EIMERIA (COCCIDIUM) AVIUM. (Macrogamete formation.) e p. 240.] "GROUSE DISEASE " COCCIDIOSIS 241 The merozoites originally produced in the duodenum pass lower down the gut and reach the caeca. At the ileo-csecal junction the epithelium is attacked again, and the merozoites rapidly grow to schizonts, which produce new generations of merozoites, so that the caeca soon contain very large numbers of the parasites. Probably Coccidiosis set up in the duodenal waH is sufficient to kill very young chicks, e.g., chicks eight to ten days old, while older chicks dying at the age of about four to six weeks may have partially recovered from duodenal Coccidiosis, but succumb to Coccidiosis in the caecum (typhlitic Coccidiosis). In cases of intense duodenal Coccidiosis, merozoites are found free in the intestinal contents, and even in freshly shed faeces. Sooner or later a limit is reached, both to the power of the Grouse chick to provide nourishment for the parasite, and to the multiplicative capacity of the parasite itself. In other words, the host begins to react on the parasite. Consequent on the now unfavourable environment, the parasite proceeds to form gametes, in order that its species may be perpetuated. The gametocytes or mother cells of the gametes (PI. xxxv., Figs. 26-28 ; PI. xxxvi., Fig. 37) are modified schizonts which are of slow growth, and therefore can accumulate more reserve food material in the form of granules within their cytoplasm. The processes leading to the formation of the gametes may be termed gametogony, which we may now consider. Sexual differentiation is characteristic of the gametes of Coccidia, and in the case of Eimeria avium the differentiation is apparent in the gametocyte phase. Two forms of gametocytes can be distinguished. The first group are intra- cellular parasites containing large granules of food reserve within their gony. cytoplasm. These are the macro-gametocytes (PI. xxxv., Fig. 26) which give rise each to one female gamete. On the other hand, the micro - gametocytes (PI. xxxvi., Fig. 37) or male progenitors contain a little reserve food material in the form of very minute granules, distributed evenly throughout the body substance. Each micro-gametocyte gives rise to many microgametes. The structure of the macro-gametocyte and of the single macrogamete that arises from it is very difficult to interpret in Eimeria avium, on account of the large amount of reserve food material contained within the cytoplasm, ga'metocyte Further, it is very difficult to draw the exact dividing line between the macro-gametocyte and the female gamete, as the one gradually merges into the other. These forms vary from ll'S/u. to 17'5/j. in length by 6^ to ll/u. in VOL. I. Q 242 THE GROUSE IN HEALTH AND IN DISEASE breadth, as seen in sections. Many relatively large granules occur in the cytoplasm of the macro-gametocyte. As the macro-gametocyte grows from round to ovoid, these granules gradually concentrate to form larger, roundish, bsematoxylm-staining granules, which are albuminoid (PL xxxv., Fig. 29), the chromatoid granules of many authors. There are also other, non-basic staining, granules known as plastinoid granules ("granules plastiques " of Thelohan and Labbe) composed of coccidin (Labbe). These ultimately are large and round (Figs. 30-32) and are refractile in fresh preparations, where they appear yellow or greyish-green. They tend to shrink in preparations fixed with sublimate or sublimate acetic (Fig. 29). The plastinoid granules occur between and among the chromatoid granules (Figs. 30-32). In stained preparations J the granules are best seen by staining with iron-hsematoxylin followed by Van Gieson's picro-fuchsin, when the chromatoid granules appear blackish, while the plastinoid granules take on a uniform, yellowish hue. The plastinoid granules stain with lichtgriin in marked contrast with the red of safranin taken up by the chromatoid granules. With Delafield's heematoxylin, the chromatoid granules stain intensely (Figs. 29, 31, 32) and somewhat misleading appearances result, suggesting multiplication of the cell. As the parasite grows, the chromatoid and plastinoid granules travel towards the periphery (Figs. 29-32). The macro-gametocyte at this time encysts within the epithelium, and the chitinoid material of the cyst seems to be formed from the chromatoid granules. At any rate, the inner layer of the cyst-wall seems to take its origin therefrom (Figs. 34-36). The formation of the cyst-wall from the chromatoid granules has been noted by Simond (1897) and Wasielewski (1904) in the case of Coccidium oviforme (Eimeria stiedce of Stiles). The formation of the cyst of Eimeria avium takes place while the organism is still within the epithelium (Figs. 34, 35), and therefore the parasite encysts pre- cociously. The macrogamete at this stage is ovoid, and the number of chromatoid granules within it is reduced. The cyst formed is ultimately rather thick-walled, but a small aperture or micropyle, which may be in a slight depression, is left for the entry of the microgamete (PL xxxvi., Fig. 47). When Schaudinn investigated the life-cycle of E. schubergi, he described a process of maturation of the macro-gametocyte, whereby the karyosome of the nucleus was expelled in fragments. I regret that I am not at all sure as to the fate of the karyosome of the macro-gametocyte of E. avium. Several causes combine to defeat the attempts made to elucidate this subject. In the first place, 1 The reactions of the granules are discussed by Labbe (1896) and by Minchin (1903). PLATE XXXVI. I ' 'IS .f " * V'.-v 33. 37. - v 43. 42. 4, 39. ^ijjM 45- 53. H.B.Fanlham del 57. EIMERIA (COCCIDIUM) AVIUM. (Microgametes, Sporogony.) 58. E. Wilson, Cambridge. 243.] "GROUSE DISEASE " COCCIDIOSIS 243 the entire parasite (E. avium) is much smaller than E. schubergi, and its karyosome is not nearly so well differentiated a structure. Further, the presence of the chromatoid granules, which stain deeply with basic stains, much confuses the structure. Similar causes prevail in E. oviforme (E. stiedce), as I can vouch from personal observation, and Wasielewski (1904, p. 54) states that he is unable to follow the maturation process in E. oviforme. It may be that E. avium is like some other Coccidia (e.g., C. lacazei C. proprium, Adelea ovata) where the karyosome is retained in the gamete and is left behind in the residual protoplasm of the oocyst. On a few occasions, I have observed a small chromatin-like granule in the oocyst residuum (PL xxxvi., Fig. 57), and this body may be the karyosome of the macro-gametocyte. E. avium is distinguished by having a very small cystal residuum, which, together with the smallness of the karyosome, and indeed of the whole parasite, increases the difficulty of investiga- tion. However, at the time of fertilisation, the distinctness of the karyosome of the macrogamete has disappeared (PI. xxxv., Figs. 29-36), and the nucleus of the macrogamete appears to contain granules of chromatin which are rather indistinct. The micro-gametocyte J (PI. xxxvi., Fig. 37) is an ovoid cell about 13^ long and 8/u. broad in the specimens that I have seen. It possesses a central nucleus contain- ing a karyosome. The process of the formation of the microgametes of E. avium is as follows : The chromatin of the nucleus, largely concen- trated in the karyosome, breaks up (Figs. 38-40) into minute granules or chromidia which pass towards the surface of the cell, where they appear to form a very fine chromidial network (Fig. 38). The chromidia then collect into groups or patches, arranged in the form of minute, irregular loops with central hollows (Figs. 38, 39). These chromatic loops form a number of minute, flexible, rod-like bodies, composed almost entirely of chromatin (Figs. 41-45). These are the young microgametes (Figs. 43-46). The adult microgametes are small parasites, their chromatic bodies measuring 3/ to 4/u in length, possessing a rod-like, some- what curved body composed of a core of chromatin, which is surrounded by a tenuous film of cytoplasm, prolonged outwards to form two fine flagella (Figs. 44, 46). The flagellum, which I term the posterior flagellum, trails behind the organism, and is practically a continuation of its body ; the other flagellum is at the opposite end of the body, and so is termed the anterior flagellum. In life, the microgametes are capable of serpentiform movements. Owing to the minute size 1 Uni - nucleate micro - gametocytes seemed rare in preparations, for the cell rapidly proceeds to form many microgametes. 244 THE GROUSE IN HEALTH AND IN DISEASE of the microgamete (about 3 M to 4/* long) it is only with the greatest difficulty that the flagella can be discerned. The whole of the micro-gametocyte is not used in the formation of the micro- gametes. When separation of the microgametes from their mother cell occurs, a large amount of the body-substance of the latter remains as a somewhat faint staining residuum, in which the pale staining remains of the karyosome (Fig. 43, cf. Fig. 38) can sometimes be distinguished. The residuum takes no further part in the vital activities of the parasite. The microgametes are set free into the lumen of the gut, and proceed to seek out the macrogametes. When the macrogamete has attained its maximum development, it often lies in the epithelium, near the outer edge of the tissue, or may even burst through the Fertiiisa- attenuate wall of the host-cell and so reach the margin of the lumen of the gut. The minute but active microgametes (PL xxxvi., Fig. 46) mean- while have broken away from the residual protoplasm of the host-cell, and swum out with rapid lashing movements of their flagella into the gut. Here they are attracted, possibly by some chemiotactic substance, towards the macrogametes. The micro- gametes swarm round the micropyle of the macrogamete (PL xxxvi., Fig. 47 1 ) and several have been seen trying to enter it simultaneously. The nucleus of the macrogamete travels upwards nearer the micropyle, and before long one microgamete effects an entry (Fig. 47 '), appears to bore its way into the female, reach the nucleus, and finally be lost to view. The macrogamete secretes a plug of protoplasm across the micropyle, whereby other microgametes are excluded, and the individuals thus shut out degenerate (Fig. 48). Such is the process of conjuga- tion as seen in the living organism, and the evidence of stained preparations is fully confirmatory of what has just been described. Owing to the presence of granules in the macrogamete it is extremely difficult to follow the subsequent stages of fertilisation. Occasionally there are indications- of a fertilisation spindle (Figs. 50, 51), but the nature of the material frequently precluded observation of the same. The term " fertilisation spindle " is not exactly a happy one, for the object of that structure is the intimate intermingling of the chromatin of the uniting gametes. After the microgamete has reached the nucleus of the macrogamete, fusion 1 See also PI. xxxvm., Fig. 3, p. 252. PLATE XXXVII. H.B Fanlham del . EIMER1A (COCCIDIUM) AVIUM. (Sporogony.) 83. E.Wilson, Cambridge. Opposite p. 2-15.') "GROUSE DISEASE " COCCIDIOSIS 245 occurs and a zygote is produced. The contents of the zygote at first fill the oval oocyst (PI. xxxvi., Figs. 49-52), but gradually they shrink away from the poles. 1 The oocyst itself may increase slightly in size during the con- centration of its contents, which ultimately form a globular mass, consisting of cytoplasm rich in fatty matters, within which is a nucleus, usually centrally placed. The nucleus (synkaryon) of the zygote proceeds to divide directly, first into two (Figs. 53, 56) and then into four (Fig. 54), the divisions following one another very rapidly. The granular protoplasm segments around the nuclei, and four sporoblasts (Fig. 57) are produced, each sporoblast separating from its neighbours as a small, rounded body (Figs. 55-57). Occasionally oocysts containing two ovoid masses of protoplasm (PI. xxxvn., Fig. 82) are seen, but as a rule the form containing four sporoblasts is the one found, the four sporoblasts being formed almost concurrently. The sporoblasts become ovoid (PI. xxxvi., Fig. 58 ; PL xxxvn., Fig. 68), and each gradually secretes a tough, chitinoid sporocyst, usually differentiated as epispore and endospore, and so becomes a firm, resistant spore (PI. xxxvn., Figs. 71-76). A minute amount of the cytoplasm of the zygote is not used in spore formation, but remains within the zygote as a small cystal residuum. The sporocysts continue within the oocysts for some time, during which period each sporocyst undergoes developmental changes, leading to the production of actively motile sporozoites. The contents of the spore at first are homogeneous (PI. xxxvn., Figs. 68-70), but gradually two refractile bodies or vacuoles appear at either end (Fig. 73), and the protoplasm gradually concentrates into two masses, just internal to each vacuole. The nucleus is at first central, but divides into two, and the halves migrate to the opposite poles of the sporocyst (PI. xxxvi., Fig. 58). The protoplasmic masses gradually displace the polar vesicles, so that the two vacuoles move towards the centre and coalesce (PI. xxxvn., Fig. 73), leaving nearly all the protoplasm of the sporocyst in two masses, one at each end (Fig. 71). Each of the protoplasmic masses gradually becomes vermiform, extending along one edge of the spore (Figs. 71, 72). Two vermiform sporozoites are thus formed (Figs. 72, 74), sometimes with their more rounded ends placed at opposite ends of the sporocyst (tete-beche) (Figs. 72, 74, 75), sometimes with the slightly swollen ends side by side (PI. xxxvi., Fig. 59 ; PI. xxxvn., Fig. 76), the sporozoites being capable of movement within the spore just previous to their escape. There is a slight sporal residuum. 1 In some cases the zygote-contents of the oocyst may be slightly nearer one pole than the other. 246 THE GROUSE IN HEALTH AND IN DISEASE The sporocysts when quite ripe tend to become more pointed at one end (PI. xxxvi., Fig. 60; PL XXXVIL, Figs. 71, 75, 76), where a slight thickening or small Stieda's plate (Fig. 71) may appear, which is a point of weakness, for here a rupture may occur under the action of the digestive juices of the fresh host, forming a sort of micropyle through which the sporozoites escape. Partially ruptured sporocysts are sometimes found (PL xxxvi., Figs. 59, 60). In the case of Grouse chicks dying from acute Coccidiosis, ripe sporocysts have been found in the ceecal walls themselves, as well as in the caecal contents, though usually mature sporocvsts are found in caecal droppings that have been exposed. The oocysts of Eimeria avium show a fair amount of variation among them- selves. Usually the oocysts are oval (PL xxxvu., Figs. 65-68, 71, 72, 77, 78), actually measured specimens varying from 25/* to 35/x in length and from 14^ to 20/x in breadth. Sometimes the oocysts are not oval but subspherical (Fig. 70), and these are from 18/ to 20/x in diameter. Somewhat pyriform or egg-shaped oocysts (Fig. 69) are intermediate in size between the oval and subspherical forms. Morse (1908) noted the occurrence of both round and oval oocysts when investi- gating white diarrhoea of fowls, in which Coccidiosis played an important part. Among the oocysts of E. avium certain were found with somewhat squarish ends (Fig. 78), while others had a slight depression at the apex (Fig. 79), but their development was identical with that of the more common forms. Occasionally, oocysts with two sporocysts only (Figs. 81, 82) were found, but these were abnormal forms, as was also a parasite (Fig. 83) in which the cytoplasm extended in a cone or funnel-like fashion to the edge of the oocyst. The size and shape of the oocysts are largely determined by the space in which the macrogamete develops and the amount of food available for the parasite. When there are many Eimeria present in any particular region of the gut, the oocysts produced are relatively small, while where abundance of space arid nourishment are available, the oocysts tend to be large. From experiments made by feeding birds with coccidian oocysts, I conclude that schizogony takes from four to five days. Uni-nucleate oocysts mature their sporocysts in two to three days. The period for the total life-history of the parasite would be from eight to ten days. The larvae and imagines of Svatoplmga stercoraria, the dung-fly, ingest the oocysts of E. avium along with the Grouse faeces. The oocysts pass through the bodies of the larvse uninjured, and are scattered with the excrement, thus serving to disperse the spores to some extent. "GROUSE DISEASE" COCCIDIOSIS 247 IV. SUMMARY OF THE LIFE-HISTORY OF EIMERJA AVIUM. The life-cycle of Eimeria avium is complicated, even though the organism completes its development within one host. The life-history may be represented diagrammatically as in Text-Fig. 1, A-T (p. 248). Beginning as a sporozoite (PL xxxiv., Fig. 2 ; Text- Fig. 1, A) liberated by the action of the pancreatic juice of the Grouse, the parasite rapidly penetrates an epithelial cell of the duodenum (Text-Fig. 1, B) and entering the cell rounds up (Text-Fig. 1, C) and becomes a passive growing trbphozoite (PI. xxxiv., Figs. 3-7 ; Text-Fig. 1, D). After a period of rapid growth, during which time the trophozoite (Figs. 8-11) practically destroys the cell harbour- ing it, the parasite enters upon an asexual, multiplicative phase termed schizogony. The schizont is at first uni-nucleate (Fig. 12 ; Text-Fig. 1, D) but the nucleus soon fragments (Figs. 12, 13), the daughter nuclei migrate to the periphery (Figs. 14-16 ; Text-Fig. 1, E), cytoplasm segregates around each (Text-Fig. 1, F), and the daughter forms thus produced become meridionally arranged, like the segments of an orange, the arrangement of the merozoites being "en barillet" (PI. xxxiv., Figs. 17-22; PI. xxxv., Figs. 23-25 ; Text-Fig. 1, G). Each merozoite is a small, vermicular organism, having a nucleus with a somewhat ill-defined karyosome usually to one side (Fig. 24). The groups of merozoites break up (Text-Fig. 1, H), and the free germs seek out and enter an hitherto uninfected cell where the parasite again assumes the trophic phase and then undergoes division as before. Several successive generations of schizonts and merozoites are thus pro- duced, resulting in a great destruction of the gut-epithelium of the host. Finally a limit is reached to the ability of the host to provide nourishment and to the multiplicative powers of the parasite, and this results in the onset of sexual differentiation. Gametogony may occur both in the duodenum and csecum. Certain schizonts become considerably modified in one of two directions. In the first case, food material accumulates, and a large, uni-nucleate food-laden form is produced (Figs. 26-30). This is the macro-gametocyte (Text-Fig. 1,1?), destined to give rise to a single macrogamete (Text-Fig. 1, J ?). In the second instance (Text- Fig. 1, !. et Ge"n., ser. iii. t. 4, pp. 517-654, pis. 12-18. LABBE", A. (1899). "Sporozoa" in Das Tierreich, Lief. 5, pp. 61, 68. M'FADYEAN, J. (1894). " Some Observations regarding the Coccidium oviforme " and " Intestinal Psorospermosis in the Pheasant." Journ. Comp. Path. & Therapeutics, vii, pp. 131-137. METZNER, B, (1903). " Untersuchungen an Coccidium cuniculi." Arch. f. Protistenkunde, ii. pp. 13-72, pi. ii. MINCHIN, E. A. (1903). "Sporozoa" in Lankester's "Treatise on Zoology," pt. i. fasc. 2, (C'occidiidea, pp. 204-238.) MORSE, G. B. (1908). "White Diarrhoea of Chicks, with Notes on Coccidiosis in Birds." Circular 128, U.S. Dept. Agricult., Bureau of Animal Industry. NEUMANN, L. G., and MACQUEEN, J. (1905). A Treatise on Parasites and Parasitic Diseases of Domesticated Animals. 2nd edition, 697 pages. London : Balliere. (See pp. 404-417.) PERRONCITO, E. (1876). "Nuove caso di psorospermosi intestinale in una gallina." Annali Accad. Agricoltura, Torino, xix. i. PFEIFFER, R. (1892)." Die Coccidienkrankheit der Kaninchen." Berlin. 272 THE GROUSE IN HEALTH AND IN DISEASE EAILLIET, A. (1895). Traite de Zoologie m^dicale et agricole. 2nd Edition. 1303 pages. Paris : Asselin et Houzeau. (See pp. 142-144.) EAILLIET, A., et LUCET, A. (1891). "Note sur quelques especes de Coccidies encore peu e"tudie"es." Bull. Soc. Zool. France, xvd. pp. 246-250. EETTGEK, L. F. (1909)." Further Studies on Fatal Septicaemia in Young Chickens, or ' White Diarrhoea.'" Journ. Med. Research, xxi. pp. 115-123. SCHAUDINN, F. (1900). " Untersuchungen iiber den Generations-wechsel bei Coccidien." Zool. Jahrbucher, Abt. f. Anat., xiii. 2, pp. 197-292, 4 pis. SILVESTEINI, A., e EIVOLTA, S. (1873). " Psorospermi epizootica nei gallinacei." Giorn. d anat. fisiol. e patol. de animali, Pisa, v. pp. 42-53. SIMOND, P. L. (1897). " Involution des Sporozoaires du genre Coccidium." Ann. Inst. Pasteur, xi. pp. 545-581, 2 pis. WASIELEWSKI, Th. von (1904). " Studien und Mikrophotogramme zur Kenntnis der pathogenen Protozoen." Heft i., Coccidia. 118 pp., 7 pis. Leipzig: J. A. Barth. CHAPTER XII " GROUSE DISEASE " CONTINUED PATHOLOGY 1 By Dr L. Cobbett and Dr G. S. Graham- Smith THE fact that wild animals are subject, like man, to diseases does not obtrude itself upon our notice, probably because they often hide themselves when ill, and creep into some corner to die, and perhaps because they i n t ro duo- have less aptitude for expressing their sufferings. However this tlon- may be, they bear so generally the aspect of perfect health that when attacked by a serious epizootic disorder, the latter gets dubbed with . J A Disease in the name of the species it attacks ; and so one hears of silk-worm wild animals. disease, horse sickness, or swine fever, as though these were the only diseases from which those species suffer. The Grouse, like other animals, suffers, doubtless, from a variety of diseases and disorders, but one of these, it is held, so far exceeds all the rest in importance that it has earned for itself the name of " Grouse Disease." Sportsmen and gamekeepers bear undivided testimony to the existence Disease in of this epizootic, which is observed with varying severity and Grouse - regularity in spring and autumn ; but it is not easy to be certain whether in " Grouse Disease " we have to do with a specific infectious disease, as is generally assumed, or merely with a series of disastrous consequences set in train by unusual privation, due perhaps to a bad season. Still less easy is it, in the case of any given bird, to tell whether or not it is suffering, or has suffered, from " Grouse Disease," especially at a time when birds are dying in unusual numbers ; for even if we agree that there is a specific infection, we must admit also that privation claims its toll, and which of the two our bird is suffering from is not easy to .decide, even after it is dead, for " Grouse Disease " has no characteristic symptoms, or very obvious macroscopic lesions. 1 Reprinted from The Journal of Hygiene, vol. x., No. 1, June 1910. VOL. I. 273 S 274 THE GROUSE IN HEALTH AND IN DISEASE Our work has been done both with diseased and healthy birds. The former were caught by the keepers in a feeble or dying condition, at times Specimens wnen dead birds were being picked up in considerable numbers on Grouse* 8 ** 1 * ne moor > an ^ it was consequently believed that "Grouse Disease" was examined, prevalent. But the mortality then was, we believe, not very great, in fact insignificant when compared with the really bad years such, for example, as 1873, and it is, we suppose, just possible that we never came across the genuine epizootic " Grouse Disease " at all. The diseased birds which were subjected to bacteriological examination were nearly all caught alive and brought or sent to the temporary laboratory. Some, of course, died on the journey, but in only a few preliminary instances were cultures made from the latter, and then only when it was exactly known when the bird was last seen alive. In addition to these birds from which cultures were made, many others which were picked up dead were examined for lesions and gross parasites. As will be easily understood the difficulty of obtaining diseased birds alive was very great, and the number fully investigated therefore very small. The control observations on normal birds were more numerous ; for, through the kindness of the members and correspondents of the Committee and others, we had no difficulty in obtaining as many as we wanted. Some Control observa- few oi these were examined in Scotland, but the great majority were received alive in our laboratory at Cambridge. A considerable number of these were caught for us by the keepers, and since it is no doubt easier to catch a feeble bird than a strong one, it may be that they do not fairly represent the average normal bird. It is probable, however, that they do not fall far short, if at all, of this standard, for they were plump and of good weight. They, of course, contained numerous entozoa, as do also the strongest birds which fall to the gun. The rest were hand-reared birds kept in captivity. The first to attribute " Grouse Disease " to a living parasite was, we believe, Cobbold 1 (1873) who drew attention to the presence of the small nematode worm, Trichostrongylus pergracilis, often in large numbers in the caeca of Grouse which were supposed to have died of the disease. Nineteen years later Klein* (1892) investigated the disease, and came to the conclusion that it was "an acute infectious pneumonia" caused 1 The "Grouse Disease," the Field Office, London, 1873. 2 "The Etiology and Pathology of Grouse Disease, Fowl Enteritis and some other Diseases affecting Birds." London : Macmillan & Co., 1892. "GROUSE DISEASE "PATHOLOGY 275 by a specific bacillus, which he found in the blood and organs of birds which had succumbed to the disease. But neither of these theories of " Grouse Disease " has found general acceptance. Against Cobbold's view is often urged the well- established fact that Trichostrongylus pergracilis is present practically without exception in all normal wild Grouse (and often too in extraordinary numbers) and it has never hitherto been clearly shown to be more numerous in individuals believed to be suffering from " Grouse Disease " than in others. Klein's bacillus on the other hand has long been suspected of being no other than Bacillus coli, which, as is well known, rapidly invades the tissues after death. C. G. Seligmann, who was the first to investigate the bacteriology of " Grouse Disease " for the Committee, but who was unfortunately called away for other work before they were completed, had already, in 1907, come to the conclusion that Klein's bacillus was one of the coli group, and was not the cause of "Grouse Disease." To these points we must return when we have recorded our own observations. It is necessary at this stage to explain how we came to be associated with the work, and what facilities we had for carrying it out. " Grouse Disease " having been reported in Scotland early in May 1908, we were invited to undertake bacteriological investigations, and accordingly Dr Cobbett proceeded north to commence preliminary work. Some M etho( j sof rooms at Beaufort Castle were converted by Lord Lovat into a ^es U tig S temporary laboratory, and every effort made by his staff of keepers tlon< to procure diseased birds in a living condition. At the same time owners of Grouse moors in the neighbourhood were asked to procure living sickly birds if possible. Some days later a move was made to Mr Perrins' moor at Ardross, where Mr Cuthbert kindly placed a room in his own house at our disposal for use as a laboratory. The visit terminated after a week, but during the time eleven diseased birds and one normal bird were examined together with others picked up dead on the moors. The latter were, of course, useless for bacteriological examination since in all cultures made from the organs of birds which have been dead for some time, whether diseased or healthy, and of birds which have been shot and wounded in the abdomen, Bacillus coli and other intestinal bacteria occur in large numbers. A second visit to Scotland was made from August 25th to September 1st. During that time eight fresh Grouse were examined for bacteria, one being a bird caught when obviously ill on Cawdor Moor and received alive. 276 THE GROUSE IN HEALTH AND IN DISEASE After this, work was continued in Cambridge on normal birds which reached us alive, and on sickly birds caught alive, immediately killed and packed in ice and sent to us from time to time from various moors as occasion offered. 1 During the visits to Scotland it was, of course, not possible to carry out all the precautionary measures which are described later as having been taken when working in our own laboratories at Cambridge, but the most important of these precautions were observed, such, for example, as plucking the birds before they were brought into the laboratory, the free use of the flame for singeing, and of the actual cautery for destroying any stray particles of feather, and for burning the skin through which the incisions were made. In the preliminary experiments also the method of getting at the lungs from behind, which is described later, was adopted ; and emulsions of the organs were made between sterilised plates ; but the glass frame, in which this was done at Cambridge, had not been adopted at the time of the earlier experiments. One of the first objects of the experiments was to seek for Klein's bacillus, and to compare it with other members of the colon group in the light of Firgt the great advances in bacteriology since Klein's observations were hivestfga! made eighteen years ago. The next was to look for characteristic tion - lesions. The preliminary observations in Scotland showed at once the presence of bacilli of the colon type, which could not be distinguished from Klein's bacillus, in the livers and sometimes in the other organs of diseased Presence of Bacillus Grouse, but it soon became evident that these micro-organisms might be present also in the organs of Grouse presumably quite healthy. No pneumonia was seen in any of the birds examined by us in a perfectly fresh condition, the lungs being always pale pink in colour and free from congestion. In birds picked up dead on the moor it was not always easy to make a definite statement about the lungs as they were often deeply stained and otherwise altered, but in the fresher specimens it was apparent that there was no pneumonia. In the fresh, diseased birds the livers were not obviously altered, though in those birds which were picked up dead they often showed more or less of that blackish colour, which has sometimes been described as characteristic of "Grouse Disease," but which is certainly due to 1 Cultures were never made except from birds which reached us alive. "GROUSE DISEASE "PATHOLOGY 277 post-mortem changes. We had the opportunity of seeing many of these birds, for Dr E. A. Wilson, the Committee's field observer, was working at Beaufort at the same time as ourselves, and it was he who first showed to us the entozoal and other parasites of the Grouse. He, too, it was p resence of who first pointed out to us that the most notable lesions were in another the cseca. The mucous membrane often appeared deeply reddened P arasites - along the convexities of the longitudinal ridges, and sometimes thickened. To the naked eye, or with the aid of a hand lens, it was plain that con- siderable pathological change had taken place here, but there was no obvious ulceration. There were always large numbers of Strongyli in these cseca. This condition was most advanced in birds which were picked up dead, but it was no post-mortem change, for it was found also in weakly birds which were brought to us alive. There were in these birds also many large tape- worms, Davainea urogalli, in the intestine, fragments of which were found, though rarely, in the cseca also. In the birds examined during the spring there were invariably enormous numbers of the slender tapeworm, Hymenolepis microps, in the duodenum, and the mucous membrane of this part of the intestine was reddened. It was therefore necessary to carefully compare normal and diseased birds (a) as to numbers of Strongyli; (b) as to liability to contain living bacilli in their organs; (c) to make a detailed examination of the lesions in the csecal mucous membrane, and to see what relation this had to the nematodes on the one hand, and the bacilli on the other; and lastly (d) to find out whether or not, the bacilli exerted any pathogenic action. It seemed possible that the Strongyli might be the cause of the changes in the csecal mucous membrane ; that these changes might admit the intestinal bacteria to the liver and other organs of the body, and that these together with other pathogenic products abnormally absorbed from the diseased cseca, or possibly the mere interference with absorption caused by that disease, might lead to the death of the birds. All the diseased birds examined were considerably under weight and wasted. We never came across any instance of a bird dying No diseased plump and in good condition, unless indeed its death could clearly 1 ^ r go f d' md be attributed to some other cause, such as accident. condition. It was recognised from the first that, if micro-organisms were present in the organs in small numbers only, somewhat large amounts of tissue might 278 THE GROUSE IN HEALTH AND IN DISEASE have to be used in order to obtain colonies on solid culture media. It was further recognised that the tissue would have to be crushed into a making 30 pulp, which could be spread more or less evenly over the surface fromthe f *h e medium, in order that any micro-organisms which might C be present should have a chance of coming into contact with it. Moreover, it was clearly seen that in carrying out experiments of this kind the chances of accidental contamination were not inconsiderable. The methods which were first employed in Scotland were later somewhat modified when the investigations were subsequently continued in Cambridge. The precise conditions under which these experiments were conducted are matters of considerable importance, since upon them depend the reliability of the results which were obtained. We have therefore no hesitation in describing the methods in detail. Previous to beginning an experiment the room was carefully prepared. All dust was removed from the window ledges and elsewhere, and the floor and bench were flooded with a mixture of glycerine and lysol to Preoau- 6 J tions lay the dust. All the windows and ventilation shafts were closed against aerial con- during the actual operation of making the cultures. As a further tamination. . . ..,. i i i precaution against aerial contamination the tissues were crushed inside a glass frame which was constructed as follows (PI. xxxix., Fig. 1) : Two sheets of plate glass, 21x8 inches, formed the top and bottom respectively, the former being supported on blocks of wood, which formed the sides. The back also was formed of a sheet of plate glass, and the front was closed by a curtain of linen, soaked in lysol, which could be partially turned back when required. The joints of the frame were made draught-proof by means of rubber tubing. On the floor of the frame another sheet of plate glass, which extended the whole length, but was 3 inches narrower than the bottom, was placed towards the back, so as to form a ledge near the centre of the floor, upon which the plates used for crushing the tissues could be con- veniently manipulated, and yet be covered by the roof. The height of the frame from the top to this ledge was 3^ inches. Before use the frame was washed out with a mixture of glycerine and lysol. In order to estimate the risk of aerial contamination agar plates were exposed on the bench and inside the frame during the whole period of time the cultures were being made. The birds, if living, were killed by decapitation, weighed and immediately PLATE XXXIX. (1) APPARATUS FOR MAKING CULTURES. (2) ALIMENTARY CANAL OP GROUSE. FIG. 1. Fir.. 2. Flo. 1. (1 nat. si/e) showing the glass fin me in which the crushing of the tissues was done. On the ledge are three pairs of ground glass plates. One of the plates uf the pair on the left is being held up in the manner in which this was done preparatory to placing a piece of tissue between the plates. FIG. 2. (J nat. size) showing the alimentary canal of a normal Grouse (No. 81) from the gizzard to the anus Gizzard fa). duodenum, enclosing the pancreas ((,), intestine (c\ cajca (d, isi 288331 64 G2 365-^375 66 456490 Fin. 3. G3 1103-1403 61 52 48 65 5!) 50 4!) 4 (i. 1 ! 51 64 02 07 00 Flc. 4. 54 56 53 61 Fl<;. 3. (J oat. size) showing small test tubes arranged in pairs containing the Strongyli collected from the two c:vca of eleven Grouse. The serial Dumber of the Grouse is written on the top, with the number of Strongyli present in each tube immediately below. Fl. 4. (i nat. size) showing small test tubes containing the Strongyli collected from both cii'cn of eighteen Grouse. No Strongyli were found in the circa of Grouse No. a'2, and in this case the test tube contains thirty-two specimens of Jletfntkis fnijjUfoya. The serial number of the Grouse is printed opposite each tube. Opposite p. 283. J " GROUSE DISEASE "PATHOLOGY 283 their length, their contents turned out, and their mucous membrane scraped. All the material liable to contain Strongyli was thus collected. Small quantities were shaken up with water in a large test-tube, and poured out little by little into a Petri dish containing water. With suitable illumination the Strongyli could be clearly seen and picked out with a mounted needle and counted. When the contents of the caeca were drier than usual, and did not readily break up when shaken with water, they were disintegrated by rubbing between the flat surface of a rubber bung and the bottom of a Petri dish. There can be no doubt that, while some Strongyli must have escaped notice, this method gave a close approximation to the numbers which were actually present quite close enough for the purposes of our Inquiry. In nearly all cases the worms in the two caeca were separately counted, usually by different observers. As may be seen, by reference to Table I. and PI. XL., Fig. 3, in all but two birds (Nos. 57 and 67) approximately equal numbers were present in the two caeca. We thought, therefore, that in our future investigations a sufficiently accurate estimation of the number of Strongyli might be arrived at by counting those present in one caecum and doubling the number found. TABLE I. SHOWING THE KESULTS or COUNTING THE STRONGYLI IN THE TWO C^ECA SEPARATELY. Grouse No. Strongyli. Total. One ciccum. Other Cittcum. 52 23 specimens of Heterakis papillosa found in one caecum and 10 in the other. 81 58 54 59 113 65 89 94 183 , 59 108 127 235 1 specimen of H. papillosa in each caecum. 46 131 128 259 55 201 214 415 63 281 252 533 64 268 303 571 57 331 268 599 62 365 375 730 67 285 548 833 68 420 457 877 66 455 490 945 56 754 1114 1868 53 1103 1403 2506 60 3118 2877 5995 1 specimen of H. papillosa in each caecum. 61 4769 4793 9562 284 THE GROUSE IN HEALTH AND IN DISEASE In the lungs, moulds and streptothrices were almost constantly found. Q , The fact that they were absent in all but a very few of the tubes results of sown from other organs indicates that they were really in the baoteno- . logical ex- birds' lungs during life, and did not get into the tubes as a result animations of the of contamination. Further, these results have been confirmed by organs. observations on a number of other animals, both mammals and birds. The other organs and blood were in the immense majority of cases free from cultivatable micro-organisms, except when Bacillus coli was present. Occasionally a single colony of some microbe would appear, perhaps a spore- bearing bacillus like Bacillus subtilis, or Sarcina lutea, or rarely a mould. On several occasions diphtheroid segmented bacilli were found. That these were sometimes accidental contaminations seems very probable, and in any case their numbers were so few as to be of little practical importance. Never- theless, it may be that some were really in the living tissues during life, and this seems more probable in the case of the segmented bacilli, for these were sometimes found in cultures from the blood, which are less liable to contamination than those from the solid organs, as well as elsewhere. More- over in one case (Grouse 37) they were also cultivated from the contents of the intestinal canal, but were only rarely met with on the exposed agar plates. The whole question of the presence of bacteria in the living organs is in course of investigation by us, and we need not dwell further on the matter here, except in so far as Bacillus coli is concerned. Beyond the oesophagus, crop, and gizzard the alimentary canal consists of the duodenum, intestine, paired caeca, and rectum (PI. xxxix., Fig. 2). The duodenum, a thin-walled light-coloured tube, 4 to 7 inches mentary long, on which the vessels are clearly seen, forms a U-shaped loop the normal of which the limbs lie in close contact with one another, the angular Grouse. 1 . . ... space on the ventral side being occupied by the pancreas. Next follows the intestine, a thicker walled tube of grey colour some 20 to 34 inches in length, and half an inch in diameter. From the junction of the intestine and rectum arise the paired caeca. Each caecum consists of a short narrow portion with small lumen next the intestine, and a long wider portion between 1 and 2 feet, or even more, in length, and about one-third of an inch in diameter. At its distal end it tapers rather suddenly to a point 1 The measurements of the various parts of the alimentary canal vary greatly in different birds. PLATE XLI. SECTIONS OF GffiCUM SHOWING TRICHOHTRONGYLUS PERGRACILIS. FIG. 5. FIG. 6. FIG. 7. FIG. 8. FIG. 9. FIG. 10. FIG. 5. (x5) showing the internal surface of the ca). FlG. 9. (xlOO) showing two specimens of T. pfrgrari/is in section in the epithelium covering a villus. Flo. 10. (xlOO) showing a specimen of T. pergracitis in section surrounded by a ring of fibrous tissue. Opposite p. 285. ] "GROUSE DISEASE "PATHOLOGY 285 Its walls are thinner than those of the intestine, and are marked by about nine longitudinal whitish lines. On opening the caecum well-marked longi- tudinal ridges are seen, corresponding to the lines just described. Each ridge shows alternate thicker and thinner portions. Occasionally one of the ridges may be seen to die away or fuse with its neighbour. They occur through- out the whole length of the caecum. 1 On examination under a Zeiss binocular microscope ( x 8 - 33) the mucous membrane of a Grouse (e.g., No. 81) in which no Strongyli are present, after gentle washing in a stream of water, is seen to be regularly beset with small villi of uniform size, arranged closely together on the ridges, but more widely separated in the depressions, where they seem to be less well developed. They often appear club-shaped, more especially on the ridges, where their flattened terminations, lying closely together at a uniform level, give the surface a somewhat smooth and tessellated appearance (PL XLI., Fig. 5). In birds caught on the moor (e.g., No. 69), apparently normal but infected with Strongyli, both the ridges and the villi are much larger (PI. XLI., Fig. 6). The rectum is a thick walled tube of greyish white colour, about 4 inches in length. The contents of the gut vary much in different parts. The duodenum usually contains nothing but a white, slimy mucus. The intestine contains coarsely divided particles of food, and occasional grits from the gizzard. The contents of the caeca present a marked contrast to those of the intestine, consisting of a brownish or greenish pasty mass of finely divided material. The rectum contains usually only the coarser particles of food which have never passed into the ceeca. Duodenum. At certain seasons of the year the duodenum of every wild bird examined was packed with the long thin tapeworm Hymenolepis microps. They were particularly numerous from March to May, and cai changes towards the end of August. Under these circumstances the contents mentwy appear to consist wholly of tenacious mucus, until shaken up in alcohol, when the worm becomes visible for the first time. No obvious patho- logical changes, except some reddening, were seen. Trichosoma longicolle was occasionally found in small numbers. Intestine. - - The lower half of the intestine was often found distended with tangled masses of the large tapeworm, Davainea urogalli ; they bear a less definite relation to season than does Hymenolepis. Portions 1 For a fuller description of the alimentary canal of the Grouse reference may be made to chap. v. pp. 100 et seij. 286 THE GROUSE IN HEALTH AND IN DISEASE of these worms are sometimes found bile stained. No pathological changes were noticed. Caeca. The appearance of the caecum as seen from without varied ; in some cases there were no obvious changes ; in others the cseca appeared to be some- what dilated, and sometimes they were mottled with lighter coloured O'V'C'l patches. The contents, the main portion of which was semi - fluid, often contained especially near the proximal ends dry masses, which were very adherent to the mucous membrane, and which corresponded to the whitish patches seen from the exterior. Whenever one of these masses was peeled off numerous Strongyli could be seen stretched between the mass and the mucous membrane, obviously adherent to both. The dry attached condition of these masses strongly suggested that they consisted of material which had long been retained in the gut. The small nematode, Trichostrongylus pergracilis, was often present in enormous numbers, occasionally amounting to thousands. They were particularly numerous towards the proximal ends of the caeca, especially in the stnngyius dry masses just described. Except in one instance we never failed always to find Strongyli in wild Grouse, and they were always present in large numbers in birds suffering from " Grouse Disease." The numbers present in wild Grouse did not appear to depend in any way upon the time of year. Portions of Davainea were on rare occasions seen in the cseca. 1 After washing in a gentle stream of water the mucous membrane frequently appeared reddened, especially in birds which were picked up dead on the moor. The reddening was present in many, but not in all, of the birds badly infested with Strongyli which were examined in a perfectly fresh condition. It was thought that this might possibly have been a post-mortem change, and some normal birds were kept after death for a few days before examination to see if the redness would appear in them ; but it was not seen. When examined under a Zeiss binocular microscope ( x 8 - 33) the ridges were found to be thickened, especially in patches to which the dry masses already referred to were found adherent (PI. XLI., Fig. 7). The villi were very irregular in all situations, being in places greatly hypertrophied and club-shaped both in the depressions and on the ridges, and in other places atrophied, particularly on the thickenings just mentioned. In many cases the villi on the ridges were 1 PI. XLIV. shows in diagrammatic form the alimentary canal of the Grouse and the habitats of the more important intestinal parasites. PLATE XL1I. TltWHOSTEONGYLUS PERGRACILIX AND DAVMNEA UROGALL1. MBp 1 1 .^ : "Jj Fie. 11. FIG. 13. FIG. 12. Flo. 14. FIG. 11. (x5) showing large numV>ers of T. ptrgracUit on the internal surface of the civcum of a diseased Grouse (No. 13). FIG. 12. (xlOO) showing a specimen of T. pergrncilis (in section) between two villi. The epithelium has been lost and fibrous tissue (a) has been formed within one of the villi in the neighbourhood of the worm. FlO. 13. (J nat. size) showing two tubes containing the specimens of Davainea urogatli (on the left) and of Ilymfiiolfpis microps (on the right) obtained from Grouse No. 11. FIG. 14. (nat. size) showing a tangled mass of iJavainea urogalli (partially opened out) from the intestine of a Grouse. Opposite p. 287.] "GROUSE DISEASE" PATHOLOGY 287 embedded in some cementing material, which in microscopic sections appeared to be composed of a mixture of mucous and granular ddbris, which could not be removed by gentle washing. Even after free washing numerous Strongyli could be seen adherent to the mucous membrane, and frequently penetrating between the villi (PI. XLII., Fig. 11). In some of the worst cases the ridges are so deformed as to resemble masses of coral, with smooth but irregular surfaces, on which the individual villi are frequently indistinguishable, and with cave- like depressions between them from which one or more Strongyli can be seen pro- truding (PL XLI., Fig. 8). These appearances, we believe, are due to the matting together of the villi and sometimes of the neighbouring ridges by the cementing material described above. With the small amount of material at our disposal l it was impossible to follow out in detail the various changes which occur in the cseca, and we therefore confine ourselves to comparing the condition found in severely affected birds with that found in normal birds. In the investigation of I the histological changes we had the advantage of the expert opinion of cseca> Mr T. S. P. Strangeways, Huddersfield Lecturer in Special Pathology, Cambridge. Sections of the caecum of the normal bird (No. 81) without Strongyli show the following structures. There is under the peritoneum a well-marked muscular coat, and within this delicate areolar tissue supporting a layer of well-formed connective tissue on which the mucous membrane rests. At intervals the connective tissue layer projects towards the lumen of the gut forming the central core c^cum of the ridges which have been described. At their bases these pro- longations appear bifurcated, and the spaces between the bifurcations are filled with fat and some large blood-vessels. Both the ridges and the depressions between them are covered with villi of fairly uniform length, which consist of a central core of vessels surrounded by a small quantity worms of delicate sub - epithelial connective tissue, together with a few ! lymphoid cells, covered with a single layer of columnar epithelium. Here and there in the depressions may be seen sections of lymphoid follicles covered with villi. The contents lying in the lumen of the gut consist of a mass of granular material and mucus (PL XLIIL, Figs. 15 and 16). Sections of the caecum of an apparently healthy Grouse (No. 69), with many In twenty-six specimens the contents of both caeca were used for counting the Strongyli ; and fourteen specimens arrived dead and therefore useless for minute histological examination. 288 THE GROUSE IN HEALTH AND IN DISEASE Strongyli (1460), caught on the moor differ in certain respects (PI. XLIIL, Fig. 17). The muscular walls contain distinct bands of wavy, fibrous tissue. The quantity of fibrous tissue in the cores of the ridges seems to be increased ; but fat Where . . . worms is still present in the bifurcations. The ridges are large, and the villi present in . . healthy are markedly increased in size, especially those situated near the free margins of the ridges. In the latter wavy bands of fibrous tissue may be seen ; and lymphoid cells are found in considerable numbers within all the villi. The epithelium appears hypertrophied, but is not markedly irregular except over the villi on the free margins of the ridges. Worms are uncommon except in certain situations in the depressions, where they seem to be entangled in what appears to be dry, concentrated gut contents. No lymphoid follicles can be seen. In a diseased Grouse (No. 6), in which the macroscopic changes are well marked, the following condition is found. The muscular wall contains well- in diseased mai> ked strands of fibrous tissue. The fat at the bases of the ridges Grouse. ^ as completely disappeared, and the vessels show considerable thicken- ing of their walls. The connective tissue in the cores of the ridges is also greatly increased in amount and in density, and the vessels dilated. The sub- epithelial connective tissue of the villi is also increased in amount, and the vessels in it dilated, and probably increased in number, and in some cases full of blood. The connective tissue is in most places loose and contains large numbers of cells, probably inflammatory in origin, and in some places, especially near the free ends of the villi and in the neighbourhood of the worms, shows fibroid change. The epithelium is proliferated and thrown into folds (PI. XLIIL, Fig. 18). In a Grouse (No. 15) badly infected with Strongyli, and showing well-marked macroscopic lesions, all the changes just described are more evident. Much fibrous tissue is present in the muscular coat, and the walls of the vessels are very markedly thickened. The villi appear increased in size, and their con- nective tissue is more dense, and contains a considerable amount of fibrous tissue, replacing the more delicate connective tissue. In this tissue a large number of the nuclei are clearly those of newly-formed fibrous tissue, being elongated and spindle-shaped, though round cells are still present in considerable numbers. Nuclei of the former type are now found in all situations, and are not limited to the cores of the ridges as in the case of specimens from normal birds. The epithelium shows great proliferative changes, and is thrown into irregular folds. In all specimens from diseased birds the lymphoid follicles are indistinguishable (PI. XLIIL, Figs. 19 and 20). PLATE XLIII. FIG. 17. Fie. 18. FIG. 19. SECTIONS OF OSCUM. FIG. 20. SI). The ridges (n) and villi (//) arc well Kic. 15. (xf) showing a transverse section of the c:i'cum of a normal Grouse (N< shown, and three collections of lymphoid tissue (c) are also seen. FIG. 16. { x25) showing a portion of the same pection more highly magnified. Fi<;. 17. ( X25) showing a portion of a section of the ctucum of an apparently healthy wild Grouse. (Xo. 69). Fl<;. 18. (x9) showing a transverse section of the cji-cnin of a diseased Grouse (No. 2). Flo. 19. ( X 9) showing a transverse section of the ciecnm of a diseased Grouse (No. 15) very badly infected with Strongyli. Flii. 20. (x2fj) showing a j>ortion of Fig. 19 more highly magnified. Large numbers of worms are seen in transverse section as black dots. Opposite p. 288.] "GKOUSE DISEASE "PATHOLOGY 289 In fact, the general condition shows evidence of a chronic inflammation leading to fibrosis. Large quantities of mucus are present in the intestinal contents, and the villi appear to be united together with this material, . Evidence of which penetrates to the deepest parts of the crypts between the villi. chronic . . . , inflamma- Everywhere Strongyli are present, and their relationship to the tion and structures composing the wall of the organ is of special interest (PI. XLIII., Fig. 20). They are found in large numbers both in the lumen and between the villi, in some instances having penetrated to the deepest portions of the crypts. In such cases the epithelium covering the portions of the villi adjacent to the worms is greatly altered, and a marked increase of fibrous tissue in the underlying connective tissue is frequently observed (PL XLIL, Fig. 12). In some instances the epithelium has completely disappeared all round the worm so that the latter is seen surrounded by a ring of dense fibrous tissue (PI. XLL, Fig. 10). Occasionally a worm is found lying between the epithelium and the matrix of the villus, which usually shows fibroid change in the neigh- bourhood (PI. XLI., Fig. 9). There can be little doubt, therefore, that the presence of the worms in such situations leads to chronic inflammatory changes and fibrosis. As has already been stated it began to appear probable early in the course of the work that the presence of Bacillus coli in the liver and other organs was related in some way to the numbers of Strongyli in the cseca. In several birds which had been raised in captivity in Scotland and subsequently kept in Surrey no Strongyli could be found, even after a careful search, and in their organs there were no bacilli" of the colon type (one exception). On the other hand, in the organs of Grouse C!eca - with very large numbers of Strongyli, Bacillus coli was constantly present,, either in the liver or in some other organ. In other Grouse with fewer Strongyli Bacillus coli was present in some, and appeared to be absent in others. The results obtained previous to the adoption of the counting method are shown in Table II. (p. 290), in which the birds are arranged in three classes. [TABLE. VOL. I. 290 THE GROUSE IN HEALTH AND IN DISEASE TABLE II. SHOWING THE RESULTS OF CULTURES PREVIOUS TO THE ADOPTION OF THE METHOD OF COUNTING STRONGYLI. Grouse No. Intestinil worms. Culture from the organs.' Hymenolepis. Davainea. Strongylus. Liver. Lungs. Spleen. Kidney. 5 18 o' Class I. No Stron- 19 21 o gyi 1 - 23 Numerous ; Numerous B. coli B. coli 0* No B. coli. 25 26 One Class II. 16 Few Tew 17 Few One Eggs only o' 6 Strongyli. B. coli i 30 33 do. Moderate Numerous do. Few do. B. coli incon- 34 Few Moderate do. stant. 40 do. ... ] Numerous Numerous B. coli B. coli ... 2 do. Numerous do. do. . . . . . 3 do. Few do. do. 111 4 do. Numerous do. do. . t ... 6 do. do. do. do. . Class III. 11 do. 12 do. do. do. do. do. do. do. ... Many . Strongyli. -{ B. coli 13 14 15 do. do. do. Numerous do. do. do. do. do. do. B. coli B. coli ... ... constant. 22 Two do. do. 'o B. coli 28 do. do. 29 do. do. 31 Numerous Few do. B. coli 32 Moderate Moderate do. B. coli ^ 35 Numerous Numerous 1 do. do. * Numerous portions of Daminea in the cajca. 1 In this and the following Table indicates that no organisms of the Bacillus culi type were present in the cultures, and ... that cultures were not made. 2 In the birds of Class II. the Strongyli were noted as few, but subsequent experience with counting methods showed that what appeared few to an ordinary examination might sometimes turn out to be a hundred or more when counted. In the birds of Class I. Bacillus coli was found once only in the organs, and then in a Grouse with very numerous tapeworms in the duodenum and intestine, When and numerous portions of Davainea in the cseca, a thing very rarely f u r mefoul observed and probably indicating some abnormal condition. Bacillus Bacillus mil co n was f oun( j i n the liver of one of six birds belonging to Class II. present in organs. Amongst the birds belonging to Class III. Bacillus coli was constantly PLATE XLIV. TONGUE ANUS DIAGRAM OF ALIMENTARY CANAL SHOWING HABITATS OF INTESTINAL PARASITES. E Wilson .cWet lith Cambridge Opposite p.' " GROUSE DISEASE "PATHOLOGY 291 found in the liver (one exception). In five instances they were cultivated from one of the other organs also. Since the counting of the Strongyli was systematically undertaken twenty^ three presumably healthy birds have been examined. The results confirmed the opinions previously arrived at. In this series four birds had less than one hundred Strongyli, and Bacillus coli was not found in their organs. Fifteen had Strongyli varying in number between one hundred and one thousand, and Bacillus coli was cultivated from the organs of some (eight) and not from those of others (seven). In four birds in which very large numbers of Strongyli, i.e., over one thousand, were counted, Bacillus coli was found in the livers of all. The results of these observations are given in the following table. TABLE III. SHOWING THE RESULTS OF CULTURES AFTER THE ADOPTION OF THE METHOD OF COUNTING STRONGYLI. Grouse No. Number of Strongyli. Cultures from organs. Liver. Lunga Spleen. Kidneys. 52 81 48 32 43 45 58 113 59 235 B. coli 46 259 do. 60 290 do. B. coli B. coli 49 330 47 344 B. ent. B. ent. 55 415 63 533 51 540 B. coli B. ent. B. ent. B. ent. 64 571 57 599 B. coli 62 730 do. 67 833 44 871 B. coli 66 945 54 1645 B. coli B. coli 56 1868 do. B. coli ... 60 5995 do. 61 9562 do. B. ent.=B. enttritidis. The points which come out clearly from these two tables are: (1) that when Strongyli are absent from the cseca or are present only in small p j n t s numbers (less than a hundred), intestinal bacteria, especially Bacillus ^^^ coli, are not present in the liver or other organs of the Grouse (eleven tables - 292 THE GROUSE IN HEALTH AND IN DISEASE Grouse one exception) ; (2) that a moderate number of Strongyli are present (one hundred to one thousand), Bacillus coli may or may not be present in the organs (twenty-one Grouse); and (3) that when great numbers (over one thousand) are present, Bacillus coli has invariably been found in the liver or other organs (twenty Grouse.) It has not been found possible to estimate the numbers of living Bacillus coli present from the number of colonies which grew on the tubes. Some- times, of course, we were able to make a rough guess. In some control birds, both diseased and healthy, which were examined some considerable time after death, the innumerable number of colonies on the tubes showed that Bacillus coli was at that time swarming in the tissues. But with living birds, even when very large numbers of Strongyli were present, the colonies of Bacillus coli were few in number, one or two to ten or a dozen, and rarely more than thirty. It is not claimed, of course, that the number of living Bacillus coli, in the liver for example, is exactly proportional to the number of Strongyli. Strongyli With as few Strongyli as two hundred and thirty-five, Bacillus coli not exactly has been found (one colony in one tube), and again with as many as n i ne hundred and forty-five, Bacillus coli has been absent. Doubtless other conditions which affect the health of the bird also influence the permeability of the intestinal wall to the contained bacteria. We have already shown that Strongyli are almost constantly present in the cseca of wild Grouse believed to be perfectly normal, and certainly of fair weight and in good general condition. In a few so-called healthy bersof birds they may be present literally in thousands. We were informed present in by Dr Wilson that Strongyli are more numerous in diseased than in and dis- healthy birds ; and we have ourselves examined a number of diseased '' birds brought in dead, and useless for cultural purposes, and collected the worms from them. Table IV. shows that the number of Strongyli present in diseased birds, though varying considerably, is greatly in excess of that found in the great majority of normal birds. In a small minority of the presumably Strongyli healthy birds the numbers were as large as those found in many diseased of the diseased birds. It is, of course, impossible to be certain that healthy these exceptional birds were not really suffering from the early stages of "Grouse Disease." The two (Nos. 60 and 61) with the largest numbers came from a moor on which " Grouse Disease " was prevalent at the time. " GROUSE DISEASE "PATHOLOGY 293 The presence in diseased birds of Strongyli in numbers far in excess of those found in normal birds does not of course prove that they were the cause of the disease, because it is conceivable that they may have multiplied as a consequence of the disease. Nevertheless, taken in conjunction with the changes previously described in the mucous membrane of the caecum, and the relation of the worms thereto, it is exceedingly probable that the worms are really the cause of the disease. TABLE IV. SHOWING THE EELATIVE NUMBER OF STRONGYLI IN HEALTHY BIRDS AND IN THOSE BELIEVED TO BE SUFFERING FROM " GROUSE DISEASE." Birds received alive, apparently in good health, or sent an average specimens of normal Grouse. Diseased birds picked up dead. Grouse No. Number of Strongyli. Grouse No. Number of Strongyli. 81 53 2,506 52 79 2,556 (1,278 in one csecum) 48 32 74 3,114 (1,557 43 45 78 3,340 (1,670 58 113 74 (a) 3,406 (1,703 59 46 235 259 80 75 3,840 4,352 (1,920 (2,176 50 290 39 6,230 49 47 55 330 344 415 71 73 77 7,058 7,484 8,800 (3,529 in one csecum) (3,742 (4,400 ) 63 533 72 10,266 (5,133 > 51 540 76 18,332 (9,166 1 64 571 57 599 62 730 69 730* 67 833 44 871 66 945 54 1,645 56 1,868 70 2,524* 60 5,995+ 61 9,562+ * One ca'cam only counted and the numbers doubled. f These birds came from the same moor. The question arises whether the tapeworms, often present in enormous numbers (PI. XLIL, Figs. 13 and 14) in the gut of the Grouse, act like the Strongyli and increase the permeability of the intestinal wall to bacteria. Tables V. and VI. show that there is little or no relation between the presence of tapeworms in the gut and Bacillus coli in the ^ organs, and that numerous tapeworms of either kind, Hymenolepis intestine. 294 THE GROUSE IN HEALTH AND IN DISEASE and Davainea, may be present without any Bacillus coli appearing in cultures from the liver. On the other hand, Bacillus coli may be present in the liver, and yet one or other or both of the tapeworms may be absent. TABLE V. SHOWING THAT THE PRESENCE OF HYMENOLEPIS IN THE DUODENUM IS NOT RELATED TO THE PRESENCE OF BACILLUS COLI IN THE LlVER. Grouse No. Hymenolepis. Cultures from the organs. Liver. Longi. Spleen. Kidneys. 52 81 48 43 49 58 55 59 B. coli 46 do. . 50 do. B. coli B. coli 47 B. ent. B. ent 51 B. coli B. ent do. B. ent. ' 57 do. 62 do. 44 do. 56 do. B. coli 54 do. B. coli 60 Few do. 63 Numerous 64 do. 67 do. 66 do. 61 do. B. coli B. ent.=S. enleritidis. The great numbers which both these worms may attain is almost un- believable by one who has not seen them (PI. XLII., Figs. 13 and 14). Davainea seems to be present in the intestine throughout the year. It might vaienceof appear n t without significance that Hymenolepis, so numerous fr m the 8 P r i n g to tne autumn months, during which the greatest mor t a lity among Grouse takes place, is scarce or absent during the winter, when the disease is quiescent. On the other hand, we have eased birds. not observed any gross lesions in the neighbouring mucous membrane even in the worst cases of infection with either of these worms, nor have they, as has already been shown, any relation to the presence of living intestinal bacteria in the tissues. We therefore are not inclined to believe "GROUSE DISEASE "PATHOLOGY 295 that they play any part, except perhaps a secondary one, in the causation of " Grouse Disease." TABLE VI. SHOWING THAT THE PRESENCE OF DAVAISEA IN THE INTESTINE IS NOT RELATED TO THE PRESENCE OF BACILLI'S COLI IN THE LlVEK. Grouse No. Davainea. Cultures from the organs. Liver. Lungs. Spleen. Kidneys. 52 81 48 58 59 B. coli 46 do. 60 do. B. coli B. coli 63 51 B. coli B. ent. B. ent. B. ent. 62 do. 44 do. 43 One 66 do. 56 Five B. coli B. coli 54 Six do. B. coli 47 Seven B. ent. B. ent. 55 do. 57 Eleven B. coli 67 Moderate 49 do. 64 Numerous 60 do. B. coli 61 do. do. B. mt.=B. entcritidit. In the above tables the birds are arranged in order, according to the number of tape- worms present. When two or more birds had the same number of these worms they are arranged according to the number of Strongyli. Three Grouse chicks, reared at Frimley and experimentally fed on coccidia. by Dr Wilson, were examined by cultures for the presence of intestinal organisms in their organs. The first (B. 15. Hatched 28.6.09. Faeces examined and no spores of coccidia found. Fed twice on 9.7.09 and 17.7.09 with i lver .'S? . UocciaiosiS'' faeces from other birds containing spores of coccidia. Killed 6.8.09) f iein - ' testme. was very ill and extremely emaciated when received, and was killed and examined immediately. An organism of the Bacillus enteritidis type was found in the liver, but not in the other organs. No worms of any 296 THE GROUSE IN HEALTH AND IN DISEASE kind were found in the intestine or cseca. Sections of the gut examined by Dr Fantham showed numerous coccidia in all stages of multiplication in the epithelial cells. The second chick (B. 2. Hatched at the same time and treated in the same way) was also ill when received, and was killed and examined immediately. In this case a few colonies of Bacillus coli were obtained from the liver cultures. No worms were found, and the condition of the intestine was the same as in the first chick. A third older chick (four months) which had been fed on eoccidia three weeks previously was also killed and examined. A few streptothrices developed on the cultures from the lungs, but those from the other organs remained sterile. Neither worms nor coccidia were found in the intestine or cseca. These observations seem to indicate that intestinal Coccidiosis may so injure the gut that bacteria are allowed to pass into the circulation. This conclusion is supported by eight observations on young rabbits suffering from naturally acquired Coccidiosis of the intestine, the results of which are given in the following Table. TABLE VII. SHOWING THE EESULTS OF CULTURES FROM THE ORGANS OF YOUNG RABBITS SUFFERING FROM COCCIDIOSIS. Coccidiosis. Cultures from the organs. Rabbit No. Intestine. Liver. Liver. Spleen. Lungs. Kidneys Blood. Bile. gland. 1. No lesions Well marked B. coli No nematodes. 2. Excessive * t 3. H Well marked j 4. Trace only Few small spots Many nematodes. 5. (233). 6. Well marked B. coli . (246). 7. One spot B. ent. B.ent eritidis / B. coli No nematodes. \B.ent. 8. Well marked B. coli ... B. coli B. tnt. = Ji. enteritidix. The mesenteric glands yielded intestinal bacteria in all cases. The cultures from the other organs, including the liver, yielded no intestinal bacteria when the small intestine was normal, or showed merely a trace of Coccidiosis. On the other hand, when the small intestine showed well-marked Coccidiosis Bacillus coli or Bacillus enteritidis was always present in the liver, and sometimes in the other organs. Thus the existence of Coccidiosis "GKOUSE DISEASE "PATHOLOGY 297 would seem to allow of intestinal organisms of the colon group to gain entrance into the portal blood. The existence of Coccidiosis of the liver bore no relation to the presence of Bacillus coli in that organ, even the affected bile ducts being sterile. The presence of the nematode, Oxyuris ambigua in the caecum (in moderate numbers) did not appear to have any influence on the passage of bacteria from the intestine into the blood-vessels. We have shown that Bacillus coli is constantly present in the organs of birds whose cseca contain large numbers of Strongyli. and we have shown that the latter are present in far larger numbers in diseased than in healthy birds. It may therefore be assumed that Bacillus coli, c nce * ' of Bacilha while not invariably absent from the organs of the apparently 35 Numerous Numerous Numerous Sept. 2',' 1908 36 14 37 Oct. 23, 1908 38 Numerous Numerous 39 Few Many 6,230 28 40 Few 41 Moderate Numerous Dec. 8, 1908 43 1 45 44 871 45 "6 Moderate Numerous "9 46 259 ... 47 344 48 32 49 Several 330 50 290 51 540 17,' 1909 81 21, 1908 52 * The Strongyli in one ciecum counted and number found doubled. "GROUSE DISEASE "PATHOLOGY 299 in August they were met with in moderate numbers in all the birds examined. From the beginning of September to the beginning of February they were absent from all the birds examined with one exception. The relation to season is much less marked in the case of Davainea urogalli, though it occurred in the greatest numbers at the same seasons as Hymenolepis. With regard to Trichostrongylus pergracilis it is difficult to come to any definite conclusion as to its seasonal prevalence from our own observations, conducted as they were on diseased birds at one time of year, and on healthy, often hand-reared, birds at another; but it is clear that they do not dis- appear at any season. The causes of death in the Grouse are, of course, various. We ourselves have seen pleuro-pneumonia (in a bird long kept in captivity in Cambridge), pericarditis, necrotic patches in the liver, an obscure chronic disease - r Summary. of the peritoneum, and septic infection from a gangrenous fracture of the wing. On the other hand, the great majority of birds, either picked up dead on the moor, or caught by keepers when weak and unable to fly, have been found to be all more or less in the same condition ; they were wasted, badly infested with Trichostrongylus pergracilis, and often with Davainea urogalli or Hymenolepis microps, or with both. More or less pathological change was seen in the caeca ; the mucous membrane was often reddened, and under the binocular microscope considerable changes were seen, though we did not observe gross ulceration. Sections examined under the higher powers showed chronic inflammatory changes of a serious kind, particularly in the immediate neighbourhood of the worms. Birds showing these changes we take to be representative of those suffering from the chronic form of " Grouse Disease." Whether there be also an acute epizootic disease among Grouse we cannot tell. We can only say that, so far as our experience goes, we have not seen it. We have acute "Grouse never seen pneumonia in the wild bird, and we have never seen any Disease" ofosGrvcd birds picked up dead when plump and in good condition without finding evidence that they had died of injury. We have therefore to discuss the causes of death in the chronic wasting disease, which is observed among Grouse fairly regularly in the spring and to a lesser extent in the autumn, and it is to this we refer when we speak of " Grouse Disease." First we must consider the gross intestinal parasites which occur in such 300 THE GROUSE IN HEALTH AND IN DISEASE remarkable numbers in the Grouse. The tapeworm Hymenolepis microps alone of these shows any relation in its seasonal prevalence to Effect of . ' tapeworms " Grouse Disease. This worm, according to our experience, is on health. n . . undoubtedly very numerous in the spring and autumn, the seasons when " Grouse Disease " is most frequently observed, 1 and practically dis- appears from the bird during the winter months. On the other hand, it has not appeared to be more numerous in diseased than in healthy birds. Davainea not infrequently occurs in such enormous masses as to distend the gut. Neither of these tapeworms has been found associated with any constant or serious lesions. Davainea appears to us to be the less objectionable. Hymenolepis, whose seasonal prevalence more closely agrees with that of " Grouse Disease," seems to us more likely to be harmful. The large masses in which it often exists in the narrow duodenum appear not unlikely to interfere mechanically with the free passage of food material. Both worms probably make a considerable demand for their own sustenance, even if they do not exert a more serious injurious influence. The case against the nematode, Trichostrongylus pergracilis, is much clearer, for though it is seldom entirely absent from healthy birds, neverthe- less, definite lesions in the caecum are often associated with its nematodes presence in large numbers. It probably, however, does little harm if not too numerous. With regard to the presence of this parasite in large numbers in some of the birds caught on the moor, and supposed to be normal birds, it must be remembered that strong wild Grouse are difficult to catch, and that some at least of the methods of capturing Grouse alive seem calculated to catch the weakest birds rather than the stronger ones. On the other hand, we have counted the Strongyli in a number of "normal" and diseased birds, and have found, on the whole, a great difference between the two classes ; very large numbers being always found in the diseased birds, much larger indeed than those found in all but the exceptional members of the healthy class ; and these, for reasons just stated, may perhaps be not normal at all but suffering from the early stages of "Grouse Disease." These nematodes, in birds picked up dead or brought to us by the keepers as suffering from " Grouse Disease," are, so far as our experience goes, almost 1 It is questionable whether there is ever a true outbreak of " Grouse Disease " except in the spring. Sickly birds observed in August and September are now believed to be birds recovering from the spring outbreak, vide chap. iii. p. 49, chap. v. p. 128. "GROUSE DISEASE "PATHOLOGY 301 always associated with grave changes in the mucous membrane of the caecum ; and concurrently with these changes intestinal bacteria, particularly those belonging to the Bacillus coli group, find their way into the liver, or even into the other organs. We have determined by actual worm counts and cultures that Bacillus coli is always absent from the liver (in birds examined immediately after death) when there are no Strongyli (hand-reared birds) or only very few (not exceeding one hundred in number). When more than one hundred but less than one thousand are found, Bacillus coli is some- times present in, and sometimes absent from, the organs, but when the numbers of Strongyli exceed one thousand, then Bacillus coli is always present in the liver, and occasionally in the other organs. We have not been able to satisfy ourselves that the bacilli which find their way into the organs do much harm. Some harm no doubt they do, but how much we cannot say. Microscopic examination has not revealed any profound changes in these livers. The numbers in which these bacteria penetrate into the organs is difficult to estimate because, doubtless, they soon get killed in the living tissues, so that the numbers of colonies cultivated must bear only a small proportion to the total number of bacteria which have entered the fragment of tissue examined. The number of living bacilli in the organs of these Grouse is undoubtedly small ; from which it is evident that they do not multiply in the organs. " Grouse Disease " is therefore not an infection with these bacteria. Is it a toxaemia caused by the poison liberated from bacteria which have been absorbed from the intestine, and which have almost immediately perished in the tissue ? We know that in order to produce serious mischief in animals by a single injection of dead bacteria a considerable quantity must be employed ; and it is difficult to believe, when we remember the small numbers of colonies which grew on our cultures, that relatively to this quantity the numbers of bacteria absorbed could have been very large. On the other hand, we have little information concerning the influence of the constant absorption of small numbers of bacteria, but this is believed by Adami and his school to be a potent source of disease. The fact that we have repeatedly found Bacillus coli in the livers of " normal " birds badly infected with Strongyli, prevents us from ascribing the death of the Grouse directly to these bacilli, though they probably play some part. It seems to us quite certain that the Strongylus when exceptionally numerous 302 THE GROUSE IN HEALTH AND IN DISEASE injures the mucous membrane of the cseca, and that this injury allows of the Conolu- absorption of certain intestinal micro-organisms into the portal blood, sions. j doubtless allows also of the absorption of other substances of an irritating or poisonous nature, and probably interferes with the normal selective absorption of nourishment. If we are right in thinking that the csecal contents become partly retained, and stick to the absorbing surfaces of the ridges of the mucous membrane, we have still more reason to believe that nutrition is greatly interfered with. " Grouse Disease," as we see it, appears to us not to be a specific bacterial infection. We conceive that all the birds which are more or less severely aifected by Strongyli suffer injury from this cause to an extent which is more or less proportional to the severity of the infection. Some exceptionally strong birds may stand a larger infection better than weaker birds will stand a lesser; but, on the whole, the birds with the largest numbers of Strongyli suffer most. Their nutrition is impaired owing to interference with the normal absorption of digested food, and to the abnormal absorption of soluble poisons and intestinal bacteria. Such birds become the weakest ; and when food becomes scarce, as it does at the beginning of spring, especially after bad winters or on overstocked moors, or when other harmful influences prevail, it is the weakest birds which suffer most. They die of privation acting on a constitution already weakened by the consequences of Strongylosis, while their stronger neighbours manage to pick up a living somehow, and tide over the period of distress. TABLE IX SUMMARY OF ALL OBSERVATIONS 304 THE GROUSE IN HEALTH AND IN DISEASE TABLE IX. SUMMARY OF ALL OBSERVATIONS. Trichostrongylus pergracilis. In Grouse Nos. 1-41 the Strongyli were not counted, and only portions of the ciecal contents were examined. In Grouse Nos. 43-68 (except 45) the Strongyli were counted in both CEeca separately (see p. 12). In Grouse Nos. 69-81 (indicated * in Table) the Strongyli were counted in one c:ecum and the number found doubled. No. Dato. Locality and History. Sex Weight in 028. Intestinal Worms. Cultures from Organs. Hymenolepis. Davainea. 8trongylus. Liver. 1 5.5.08 Inverness. Caught unable J 16 Numerous Numerous B. coli (12) to ny 2 6.5.08 do. do. $ 16 do. Numerous do. B. coli (several) 3 6.5.08 do. do. s ... do. Few do. B. coli (12) 4 6.5.08 do. do. $ 20 do. Numerous do. B. coli (few) 5 7.5.08 Normal hand-reared bird. 15 Frimley 6 7.5.08 Inverness. Caught unable $ 16 Numerous Numerous Numerous B. coli (several) to tiy 11 9.5.08 do. do. $ 17 do. do. do. B. coli (several) 12 9.5.08 do. do. ? ... do. do. do. B. coli (few) 13 9.5.08 do. do. ? 18 do. do. B. coli (1) 14 9.5.08 do. do. ef 16 do. do. B. coli (1) st.c 15 9.5.08 do. do. $ 23 do. Numerous do. B. coli (several) 16 2.6.08 Normal. Frimley S 15 Few ... 17 10.7.08 do. do. $ 14 Few 1 Eggs only sb 18 10.7.08 do. do. $ 21 sb 19 24.7.08 do. do. ? 23 20 28.7.08 do. do. 15 Few ... 21 5.8.08 do. do. 2 15 22 10.8.08 do. do. ? ... 2 Numerous B. coli (1) 23 16.8.08 Inverness. Apparently $ 13 Numerous Numerous B. coli (4) healthy 25 18.8.08 Normal. Frimley. $ 15 26 18.8.08 do. do. ? 13 1 S. Lutea (1) 28 Inverness Numerous B. coli (few) 29 27.8.08 Inverness. Caught unable 15 do. B. coli (1) to fly 30 26.8.08 Inverness. Apparently ? 16 Few Numerous Few healthy 31 27.8.08 do. do. $ 20 Numerou* Few Numerous 32 28.8.08 Inverness. Healthy, caught ? 16 Moderate Moderate Moderate B. coli (2) on moor 33 28.8.08 do. do. 15 Numerous Numerous Few B. coli (few) 34 29.8.08 do. do. 5 18 Few Moderate do. 35 29.8.08 Nairn. Caught on moor. ? 17 Numerous Numerous Numerous B. coli (several) Ill 36 3.9.08 Normal bird. Examined 9 i ... four days after death 37 14.9.08 Normal bird. Found dead. 2 11 Frimley 38 23.10.08 Normal bird. Died of peri- t 20 Numerous Numerous st.c (1) carditis " GROUSE DISEASE "PATHOLOGY 305 B. enter. = Bacillus of the B. enterititlis group. f = COCCUS. m mould. TABLE IX. continued. sb = spore-bearing bacillus. rf=diphtheroid bacillus. j=sarcina. b = bacillus. ,-rt. * = st reptococcus. The numbers or words in brackets indicate the number of colonies found. Cultures from Organs. Remarks. Lungs. Kidneys. Spleen. Pancreas. Bile. Blood. Rilit. B. coli (1) Ltft. Right. Left. Examined two hours after death. Moderate reddening of csecal viUi. d (3) Ctecal mucous membrane much congested. Csecal mucous membrane little st.c (2) congested. Csecal mucous membrane not congested. ... do. do. ... m(l) 6 Csecal mucous membrane much congested. ... Csecal mucousmembraneslightly B. coli . . . congested. Csecal mucous membrane not congested do. do. B. coli B. coli Csecal mucous membrane ex- ... tremely congested Csecal mucous membrane not congested. Gut wounded sx, sb sx, sb sb sb sb, m while making cultures. Csecal mucous membrane not sb sb sx sb congested, do. do. 4(1) ... Gut wounded when making cultures. in(l),sb(l) sb(l) ?m B. coli (2) ... m(l) 4(1) B. coli (1) Numerous proportions of Da- rainea in cseca. m, sx m, so c(l) m(l),d(l) m(l) . . TO (2) m, sx sb c . (1) Shot in wing. Brought in alive. m(l) m(l) 4(1) . .. ... w'(3) m(l),sb 4(1) B. coli (I) ... ... sb(l) 1(1) 6 (1) o ''(1) Ca?cal mucous membrane some- ... ... what reddened. ... ... ... VOL. I u 306 THE GROUSE IN HEALTH AND IN DISEASE TABLE IX. continued. No. Date. Locality and History. Sex. Weight in ozs. Intestinal Worms. Cultures from Organs. Hymenolepis. Dtvainea. ' Strongylus. Liver. 39 24.10.08 Lancashire. Caught unable a 18 Few Numerous 6,230 to fly 40 28.10.08 Normal. Died of pneumonia. $ 20 Few Frimley 41 28.10.08 Lancashire. Caught unable $ 20 Moderate Numerous to fly 43 8.12.08 Cumberland. Normal $ 17 1 45 44 8.12.08 do. do. ? 19 871 B. coli (4) 45 8.12.08 Nairn. Picked up dead $ 16 Moderate Numerous 46 9.12.08 Cumberland. Normal $ 16 259 B. coli (1) 47 9.12.08 do. do. ... 18 344 B. enter (several 48 9.12.08 do. do. & 32 s(2) 49 9.12.08 do. do. ? 13 Several 330 ('(1) 50 9.12.08 do. do. ? 19 290 B. coli (3) 51 9.12.08 do. do. ? 13 540 B. coli (many) 52 21.12.08 Lancashire. Normal. Hand- $ 15 reared 53 Montgomeryshire. Picked $ 16 2,506 up dead 54 3.2.09 Cumberland. Normal ? 16 6 1,645 B. coli (several) 55 3.2.09 do. do. $ 17 7 415 56 5.2.09 do. do. $ 16 5 1,868 B. coli (many) 57 5.2.09 do. do. ? 17 11 599 B. coli (several) 58 5.2.09 do. do. ? 17 113 59 6.2.09 do. do. ? 12 235 B. coli (several) 60 17.3.09 Yorkshire. Normal. Caught ? 21 Few Numerous i 5,995 B. coli (several) on moor 61 17.3.09 do. do. 21 Numerous Numerous 9,562 B. coli (several) 62 19.3.09 do. do. ? 21 730 B. coli (8) 63 20.3.09 Selkirk. Normal. Caught ? 18 Numerous 533 8(1) on moor 64 20.3.09 do. do. ? 20 do. Numerous 571 65 20.3.09 Cumberland. Shot. 2 18 do. 2 183 66 20.3.09 Selkirk. Normal. Caught ? 19 do. 1 945 o" on moor. 07 20.3.09 1 do. do. ? 18 do. Moderate 833 (!8 22.4.09 Caithness. Normal. Caught ? 16 877 ... on moor 69 27.4.09 Inverness. Normal. Caught $ 23 Numerous Numerous 730* on moor. 70 27.4.09 do. do. 23 do. do. 2,524* 71 10.5.09 Inverness. Caught, unable '?" 16 do. 7,058* to fly 72 10.5.09 Inverness. Picked up dead $ 17 do. Numerous 10,266* 73 7.5.09 Nairn. Picked up dead ? 17 do. Fragments 7,484* 74 21.5.09 Yorkshire. Picked up dead 9 17 Moderate 3,114* 74a 21.5.09 do. do. . Numerous 3,406* 75 19.5.09 do. do. "i do. Numerous 4,352* 76 19.5.09 Lancashire. Picked up dead do. 18,332* 77 19.5.09 ' Selkirk. Picked up dead "i 21 Numerous 8,800* 78 24.5.09 do. do. 9 16 do. Few 3,340* 79 3.6.09 Inverness. Picked up dead. ? 17 Few 2,556* 80 3.6.09 do. do. I 19 3,840* 81 17.12.09 Normal. Frimley ? 15 6 GEOUSB DISEASE" PATHOLOGY TABLE IX. continued. 307 Cultures from Organs. Remarks. Lungs. Kidneys. Spleen. Pancreas Bile Blood Right. Left. Right. Left. ... ... ... Arrived dead. w(l) 771(1) ... ' ... ... ... Arrived dead. ,6(1) St. C (1) ... M (1) m(l),c(l) m (I) ... m'a\ SK 6 o' ... m (l),c : (1) TO (1) <*(!) B. enter. . .. Patches of dry faecal matter SX sb adhering to ccecal wall. &/_, m m c (1) -B. coZi (1) m, sx B. coli (6) ... sx, m sx, m B. enter. B. enter. B. enter. B. enter. B. enter. Bird in very poor condition. m, c m, c . .. Thirty-two specimens of Tricho- soma longicolle in duodenum. Thirty -two specimens of Heterakis papillosa in caeca. ... Two specimens of Trichosoma longicolle in duodenum. m in B. coli (3) m sx, m s (1) B. coli c ... ... ... m m m sx, m ... s (1) m, sx sx ... One specimen of Heterakis papil- losa in each csecum. m (1) ... ... do. do. s(l) sx, m sx, m ... sx sx c(l) ... m(l) "(!) *0 ::: m (1) Arrived dead. ... ... ... do. ... ... ... ... do. m 771 ... ... CHAPTER XIII OBSERVATIONS ON THE BLOOD OF GROUSE 1 By Dr H. B. Fantham INTRODUCTION THE elements of the blood of birds are very different from those of mammals, and while much is known of the histology of mammalian blood, the investigation of introduc- the blood of birds has hitherto been very limited, and very little indeed is known of the subject. Such literature as is available on avian blood is, unfortunately, largely contradictory, and the few illustrations relating to the same have not solved entirely the difficulties connected with the cellular elements of the blood of birds. The portions of the subject that have been most adequately dealt with are those relating to certain pathological conditions, fowl cholera and fowl typhoid occurring in domestic fowls, and those relating to normal fowls' blood. In connection with both these sets of observations there are wide discrepancies between the results obtained by different investigators, and much confusion has arisen therefrom. The different results obtained by various investigators are partly explicable, for the constitution of the blood of birds may vary among individuals of the same species. Also there are differences due to age and sex, while the conditions under which the investigations are made have some influence on the result. The chief difficulties of manipulation for the investigation of the blood of such birds as Grouse are the rapidity with which coagulation occurs, and the rapid alteration and disintegration that often follows the death of the blood elements. The great rapidity of the onset of degeneration in the leucocytes is such that extreme accuracy in counts of these cellular elements is not easily obtained, and the numbers of erythrocytes and leucocytes found in different series of counts consequently bear a varying relation one to another in apparently normal birds, 1 Reprinted from the Proceedings of the Zoological Society of London, 1910. 308 13. 16 PLATE XLV. ^\>$Sp- 8. -7 C^A 4 ^ M ' 12. 17. BLOOD CELLS OF BIRDS, CHIEFLY OF GROUSE . Opposite p. 309.] OBSERVATIONS ON THE BLOOD OF GROUSE 309 even when the factors noted in the preceding paragraph have been considered. Nevertheless, the correlation of the numbers and condition of the blood-elements, particularly of the leucocytes, with the occurrence of specific protozoal and helminthic parasites, renders an examination of the blood a most useful adjunct in investigating somewhat obscure diseases. Several protozoal parasites (vide chapter xiv. p. 318), are present in Grouse, both in the blood and in the gut, and the condition of the bird's blood can be correlated with the presence of some of the individual parasites. Blood taken from a wing vein was used in the case of living birds, of which twelve were thus examined. In the case of freshly killed Grouse, blood J Methods. taken directly from the heart was employed. The usual methods and precautions were followed in securing suitable drops of blood for examination. Hayem's fluid was used as a diluent for counting the red cells of the blood, while Toison's fluid was used in the case of the leucocytes. The Thoma-Zeiss haemocytometer was employed. The disc of the counting chamber was ruled according to Zappert. A dilution of at least 200 or 250 was found to be necessary for counting the red cells, and a dilution of 20 to 25 was absolutely necessary in counting the leucocytes. Sometimes a dilution of 100 was taken in counting the leucocytes, and this greater dilution was often preferable. For differential leucocyte-counts blood-smears were made on both cover-slips and slides, especially the former. The stain generally used in making preparations for differential counting was that of Jenner. Occasionally Giemsa's stain was employed. The elements present in the blood of normal Grouse may be grouped as : (a) Erythrocytes. Cells in > 7 / T J J normal (6) Leucocytes. blood. (c) Thrombocytes. The leucocytes are further subdivided, and may be grouped as mononuclear, polymorphonuclear, and eosinophile leucocytes, and lymphocytes. Mast cells, which are markedly basophile, are also present. Erythroblasts also may be encountered. These forms may now be considered separately. (a) Erythrocytes. These are the most abundant elements in the blood. The erythrocytes or red blood corpuscles are oval in contour (PI. XLV., Fig. 1). They 310 THE GROUSE IN HEALTH AND IN DISEASE possess a well-marked oval nucleus, centrally placed. The erythrocytes of Grouse Eryth- are a ^out 11 '5/j. to 12/i long by 7^ to 7'5/j. broad. In fresh preparations rocytes. ^ Q cytoplasm of the red cells of healthy Grouse is practically homogeneous, or but very faintly granular. Stained preparations give the same results. It is rare for large granules, chromatoid granules, or vacuolations to be present in the red cells of healthy birds. The nucleus stains deeply, and shows a well-marked chromatic meshwork with small net-knots upon it at intervals. The red cells of various birds are much the same. There may be slight differ- ences in size and shape. In Figs. 2 and 3 are depicted stained specimens of the red cells of the pigeon and fowl respectively, from which it will be seen that the erythrocytes of the pigeon are slightly narrower than those of the Grouse and fowl, and somewhat less rounded at the ends. The number of red cells of Grouse varied from 3,600,000 to 5,800,000 per cubic millimetre, averaging 4,300,000 per cmm. These figures result from blood- counts of fifty birds. The number of red cells is apparently higher in cock Grouse (e.g., 4,400,000 per cmm.) than in hen Grouse (e.g., 3,800,000 per cmm.). (b) Leucocytes. The leucocytes of Grouse are a subject of much intrinsic difficulty, and it is impossible to consider the grouping arrangement given below as more than provisional. The classification of the leucocytes of birds can Leucocytes. be placed on a really sound basis only when detailed knowledge of the development of all the elements of the blood of birds has been obtained. In spite of good work by Denys, Dantschakoff, and others, such a complete developmental investigation of the blood of birds is still wanting. Owing both to the lack of time at my disposal, and to the great scarcity of quite fresh material, I am unable to attempt such an investigation, and therefore have availed myself of the classifica- tion at present adopted by such authorities as Burnett (1908), modifying their statements in accordance with my own personal observation and adding a number of details hitherto overlooked. 1. Lymphocytes (PL XLV., Figs. 5, 6). The lymphocytes are the smallest of the leucocytes. They are from 5*5^ to 8 M in diameter approximately. They are Lym . smaller than the average red corpuscles. Each lymphocyte possesses a phocytes. we ll-marked round or oval nucleus which is relatively large and occupies most of the cell. The cytoplasm of the lymphocyte is small in amount, is baso- phile, and is reduced to a rim around the nucleus. The lymphocytes have a great tendency to collect together in groups on blood-smears, and in such aggregations OBSERVATIONS ON THE BLOOD OF GROUSE 311 the cytoplasm of the members away from the periphery of the group is reduced to a minimum. The lymphocytes are sometimes subdivided into large and small varieties. The larger specimens of lymphocytes gradually merge into the small mononuclears, and the naming and classifying of such leucocytes is often a matter of personal opinion. 2. Large Mononuclear Leucocytes (Hyaline cells). These are large, approxi- mately circular cells averaging 9//, to 11 '5^ in diameter (PI. XLV., Figs. 7, 8). In a film stained with Giemsa's fluid the mononuclear leucocytes are easily Large distinguishable, not only from their large size, but also from the fact "iear that their cytoplasm stains a vivid blue and the nucleus a beautiful ' purple. The general cytoplasm of the cell is almost homogeneous in character. The nucleus of a mononuclear leucocyte of Grouse is large, occupying about half of the cell, and is often round or oval (Figs. 5, 6). At other times the nucleus is somewhat curved or indented (Fig. 8). The chromatin of the nucleus takes the form of a fairly dense mass, exhibiting in stained specimens a uniformly mottled appearance ; it is situated to one side of the cell. With Jenner's stain the nucleus colours a rather deep blue, while the cytoplasm stains only a faint blue and so is slightly basophile. As Burnett (1908, p. 35) writes: "One can find all stages between typical lymphocytes with a small amount of strongly basophile, coarsely reticular cytoplasm, and typical large mononuclears with a much larger amount of faintly basophile, finely reticular cytoplasm." 3. Polymorplionuclear leucocytes (Burnett) or Crystalloid eosinophile Cells (Cullen, Warthin). The apparently polymorphonuclear leucocytes of birds exhibit marked differences from those of mammals as regards phouuclear leucocytes. the contained granules. These cells in Grouse are round, as seen in stained preparations, and measure from 9^ to 9 '5^ in diameter (Figs. 10-12). The nucleus consists of two or more lobes, and varies in shape in other words, is polymorphous. The nucleus is fairly well stained with Jenner's stain, and is coarsely reticular (Figs. 10-12). The cytoplasm stains very faintly. Embedded in the general cytoplasm are a number of bodies or granules which stain red with Jenner's stain and are oxyphilic. The bodies are generally described as spindle-shaped with tapering ends, but their outline has also been compared with that of a torpedo or cigar (Fig. 11). Other leucocytes are found with thinner inclusions or "granules" which are rod-like in shape (Fig. 10). 312 THE GROUSE IN HEALTH AND IN DISEASE Cullen (1903) writes : " As to the nature and origin of these spindles [inclusions in the cytoplasm of the leucocytes] very little is known that is definite. They are certainly not artifacts, for they can be seen in fresh blood as well as in dried specimens. Dr Simon is of the opinion that they may be derived from the second variety [the coarsely eosinophile leucocytes, mentioned next], in which granules take the place of the spindles ; that they are crystalloids and analogous to similar formations that have been encountered in certain tissues in man, and notably in the epithelial cells of the seminal tubules. He thinks that they result from the granules through loss of water, and as a matter of fact it is possible to reconvert the crystalloids into granules in the wet preparation by adding a droplet of a dilute solution of eosin from the side of the cover-glass. Dr Simon has also noted that in certain preparations in which the eosinophilic material is present in one dense, apparently undifferentiated mass, the crystalloids separate out upon the application of heat." In a few cases, the centre of the spindle bodies is occupied by a tiny circle or dot, which does not stain as deeply as the rest of the spindle, and is refringent (Fig. 12). The presence of this central dot is noticeable in the case of large spindles. As regards the staining properties of the spindle bodies (crystalloids), I agree with Burnett that they are not intensely eosinophilic, but that " in affinity for stains the [spindle] granules resemble the polymorphs rather than the eosinophiles." Cullen, on the other hand, considers that the crystalloids are more oxyphilic than the true eosinophile leucocytes. Perhaps the differences of opinion of the various investigators are explicable by reference to slight variation in the stains used. The distribution of the cytoplasmic inclusions within the cell is dependent on the shape and position of the nucleus. 4. Eosinophile leucocytes (Burnett) or coarsely gramtlar eosinophile. (oxyphile) Cells. These cells are also present in the blood of normal Grouse (Figs. 13-15), but Eosinophile are more numerous in the blood of birds suffering from helminthiasis. leucocytes, -j^g eos i n0 phii e ce ll s are from 8yu to 10 M in diameter, and have a general resemblance to the polymorphonuclear leucocytes, only differing in the form of the inclusions or granules. The shape of the eosinophile leucocyte is round (Figs. 14, 15) or somewhat quadrilateral (Fig. 13). The general cytoplasm is pale staining and slightly reticulate in structure. The nucleus usually resembles that of the polymorphonu- clear leucocyte, and is mostly bilobed the lobes being coarsely reticular and usually staining fairly deeply. The cell-body contains numbers of coarse, oxyphile OBSERVATIONS ON THE BLOOD OF GROUSE 313 (acidophile) granules which stain deeply with eosin. The granules are often rounded (Figs. 13-15); they vary in size, some eosinophiles containing large granules (Fig. 13) which may be relatively fewer in number, while in other cases the granules are small (Fig. 14), and may be relatively more numerous. Eosinophiles with large granules a.re more prevalent. The contour of the granules is generally round, but sometimes cells containing somewhat ovoid granules are seen which stain intensely with eosin. Occasionally eosinophile cells are found in stained films, the granules of which vary in shape within the same cell, some being round, some ovoid, and some almost spindle-shaped. Such cells and their contained granules may be somewhat deformed in the making of the film, otherwise it is difficult to classify these cells, which are intermediate between crystalloid (polymorphonuclear) and granular eosinophiles. Mononuclear eosinophile cells are occasionally seen in the blood of normal Grouse, and perhaps represent an early stage of development of the polymorpho- nuclear eosinophiles. Such mononuclear cells are somewhat smaller than those depicted in PL XLV., Figs. 13-15, and have round nuclei. They are rare, and are perhaps analogous to the young eosinophile myelocytes of man. 5. Mast Cells (coarsely granular basophile cells) are present in the blood of normal Grouse (Figs. 16, 17). They are rare. The cells are more or less Mast cells. rounded, with a pale staining cytoplasm. The nucleus is usually rounded (Fig. 17) or slightly polymorphous (Fig. 16), and stains blue with Jenner's stain rather more deeply than similar cells in mammals. Basophile granules, which vary in size and in number, occur in the cytoplasm. The granules are usually rounded and stain a deep purplish colour with Jenner's stain in other words the granules are metachromatic. Mast cells measure from y^ to IG'5^ in diameter. (c) Thrombocytes also occur in the blood of Grouse (Fig. 4). In the fresh condition they suggest very narrow and slightly small erythrocytes. They xhrom- are often elliptical, with an oval nucleus centrally placed. bocytes. When stained the cell-body is pale and vacuolated, suggesting a coarsely reticular cytoplasm. The whole cell is basophile in its reactions, staining rather faintly blue with Jenner's stain. Thrombocytes in Grouse average 9^ by 4^. These elements may collect in clumps, and show a marked tendency to degeneration. 314 THE GROUSE IN HEALTH AND IN DISEASE Red cells without nuclei were occasionally found in the blood of Grouse. Such non-nucleate cells, however, were very rare. At times there also appeared to be a number of free nuclei in the blood of Grouse. In this connection we may note that Warthin (1907) found 16'5 per cent, of degenerated cells in the blood of normal fowls. Erythroblasts occur in the blood of Grouse in small numbers. The cells, which Erythro- are nucleated, are rounder than erythrocytes,and are devoid of haemoglobin. The nucleus of an ery throblast is more spherical than that of an erythrocyte. The general cytoplasm is homogeneous, staining blue with Giemsa's stain. The number of leucocytes found per cubic millimetre in the blood of apparently healthy Grouse varied from 22,000 to 50,000, averaging about 32,000 per cmm. The average results of the differential counts of leucocytes of apparently healthy Grouse may be tabulated thus : Lymphocytes . . . . . . 57 per cent. Large mononuclears . . . . . 19 Polymorphonuclears (crystalloid eosinophiles) 20 ,, Eosinophiles (coarsely granular eosinophiles) . 3 ,, Mast cells (basophiles) . . . . . 1 ,, The difficult computations are those of the large mononuclears and lymphocytes. There are many medium-sized mononuclears in Grouse, which different observers would classify differently. The association of altered conditions of the blood with the presence of protozoal parasites has been noted already, and I have found certain alterations in the Patho- relative proportions of the blood cells of Grouse that harboured protozoa biood of Leucocytozoa, Spirocheetes and Coccidia while other differences are to be associated with helminthiasis. The results may now be summarised : (a) When Spirochceta lagopodis (vide chapter xiv. p. 323) was present in the blood of Grouse, as it was to some extent in two specimens, the number of When mononuclear leucocytes increased, and these leucocytes became slightly associated enlarged and vacuolated (PI. XLV., Fig. 9). Levaditi (1901) noticed SpirocJuEta the presence of vacuolated mononuclear leucocytes in the blood of lagopodis. fowls infected with Spirochceta gallinarum, together with mononuclear and polynuclear leucocytosis. Balfour (1908) found vacuolated mononuclear leucocytes in the blood of fowls suffering from spirochsetosis in the Soudan. The infection of Grouse with S. lagopodis was probably not nearly as great as that of fowls with S. gallinarum investigated by Levaditi and Balfour. OBSEEVATIONS ON THE BLOOD OF GROUSE 315 (/3) The presence of Leucocytozoon lovati (vide' chapter xiv. p. 3 18) in the blood of Grouse is associated with mononuclear leucocytosis. A differential leuc- with Leu- ocyte count of the blood of one of the Grouse containing L. lovati gave : 2^!' Lymphocytes . . . 63 '0 per cent. Large mononuclears . . 28 '0 Polymorphonuclears . . 5 '5 ,, Eosinophiles . . . . 2'5 ,, Mast cells . . . . I'O There was also evidence of polychromatophilia in the red cells of Grouse in- fected with Leucocytozoon lovati. (y) Eimeria (Coccidium) avium (vide chapter xi. p. 235) also has its effect, indirectly, on the blood. Birds suffering from Coccidiosis became anaemic. The paleness of the blood is due to the diminished number of red cells in the blood. Estimations of the hsemoglobin-value by Tallqvist's scale * gave Eimeria 60-70 in the case of Grouse chicks suffering from Coccidiosis, 80-90 for healthy Grouse chicks. There is an increased number of polymorphonuclear leucocytes (crystalloid eosinophiles). Differential leucocyte counts of two Grouse chicks dying from Coccidiosis gave : Polymorphonuclears . . . 31 '5 to 39 '5 per cent. Eosinophiles ..... 3'5 to 5'5 ,, Large mononuclears . . " . 13 '5 to 3 TO ,, Lymphocytes 26 '0 to 50 '0 Mast cells . . . . . 0'6 per cent. In mammals an increase in the number of polymorphonuclear leucocytes occurs in inflammation, especially locally. The increase in polymorphonuclear leucocytes (crystalloid eosinophiles) is probably to be associated with the intestinal inflamma- tion caused by the presence of coccidian parasites. Similarly in a fowl chick dying of Coccidiosis, I obtained the following differential leucocyte count : Polymorphonuclears . . . . 47 per cent. Eosinophiles ..... 2 Mononuclears . . . . . 29 '5 Lymphocytes . . . . . 20 - 5 Mast cells ...... 1 1 Tallqvist's scale was used because it is easily carried in the pocket, and can be used for rapid work. 316 THE GROUSE IN HEALTH AND IN DISEASE The blood of this fowl chi'ck 1 contained basophile spindle-shaped cells (PL XLV., Fig. 18). ($) Helminthiasis is common in Grouse. The various worms found in Grouse have been well described by Dr Shipley (vide chapter x. p. 207, chapter xv. with P' 334 ancl P- Z -S-> 1909) and by Dr Leiper (vide chapter x. p. 219). helminthi- Grouse which would be considered perfectly healthy by keepers often contain worms. One of the causal factors of disease in adult Grouse is the larval stage of Trichostrongylus pergracilis. The adult Trichostrongylus occurs in the caeca of Grouse, and sets up inflammation therein. In the blood of three adult birds dying on the moors from " Grouse Disease," I obtained differential leucocyte counts which may be thus summarised : Eosinophiles . . . . 23 '5 to 42 '0 per cent. Polymorphonuclears ... 7'5 to 14'0 ,, Mononuclears . . . . 6'0 to lO'O Lymphocytes .... 44'0 to 62'5 Mast cell 0'5 per cent. Contrasting these counts with those given for normal Grouse, the occurrence of eosinophilia is deduced. All three of these birds, dying of " Grouse Disease," had many Hymenolepis microps in their duodenum in addition to Trichostrongylus in the cseca. Eosinophilia is often associated with helminthiasis in mammals. Helminthiasis in Grouse results not only in an increase in the number of eosinophile leucocytes, but also in a diminution of the number of erythrocytes in the diseased birds. Thus the number of red cells found in an adult cock Grouse dying from helminthiasis was 3,250,000 per cubic millimetre the number of red cells for a normal cock Grouse being about one million more. The haemoglobin value estimated by Tallqvist's scale was 60 for a Grouse suffering from helminthiasis and 80-90 for healthy adult Grouse. In spite of the incomplete character of this investigation of the blood of the Grouse (due to the lack both of material and time at my disposal), I think that there are sufficient results contained herein to emphasise the importance of parallel investigations of the blood in connection with all animal diseases. 1 Burnett gives the following differential leucocyte count of normal fowl's blood : Polymorphonuclear 28'8 per cent. ; eosinophiles 3'3 per cent. ; large mononuclears 5'5 per cent. ; lymphocytes 58 per cent. ; mast cells 4'3 per cent, OBSERVATIONS ON THE BLOOD OF GROUSE 317 References to Literature. ADAMI, J. G. (1907). " Inflammation : an Introduction to the Study of Pathology," 240 pages. London: Macmillan & Co. BURNETT, S. H. (1908). "The Clinical Pathology of the Blood of Domesticated Animals." 156 pages, 4 pis. Ithaca, N.Y., U.S.A. : Taylor & Carpenter. ( " Blood of Fowl," PI. 3.) CULLEN, E. K. (1903). "A Morphological Study of the Blood of Certain Fishes and Birds with Special Reference to the Leucocytes of Birds." Bull. Johns Hopkins Hosp. xiv. pp. 352-356. DANTSCHAKOFF, W. (1908). " Untersuchungen iiber die Entwicklung von Blut und Bindegewebe bei Vogeln." Archiv. f. Mikroscop. Anatomic. 73, pp. 117-181, 2 pis. DENYS, J. (1888). "La structure de la moelle des os et la genese du Sang chez les Oiseaux." La Cellule, iv. pp. 203-240, 2 pis. FANTHAM, H. B. (1910). " The Morphology and Life History of Eimeria (Coccidium) avium : a Sporozoon causing a Fatal Disease among Young Grouse." Proc. Zool. Soc. Lond. 1910, pp. 672-691, 4 pis. Vide chapter xi. p. 235. FANTHAM, H. B. (1910). " Observations on the Parasitic Protozoa of the Red Grouse (Lagopus scoticus)." Proc. Zool. Soc. Lond. 1910, pp. 692-708, 3 pis. Vide chapter xiv. p. 318. FANTHAM, H. B. (1910). "Experimental Studies on Avian Coccidiosis." Proc. Zool. Soc. Lond. 1910, pp. 708-722, 1 pi. Vide chapter xi. p. 252. MOORE, V. A. (1895-6)." Infectious Leukemia in Fowls." 12th & 13th Ann. Eept. Bureau Anim. Industry, U.S. Dept. Agric. p. 185. NEAVE, SHEFFIELD (1906). Second Report Wellcome Research Laboratories at Gordon College, Khartoum, pp. 194-196. SHIPLEY, A. E. (1909). " The Threadworms (Nematoda) of the Red Grouse (Lagopus scoticus)." Proc. Zool. Soc. Lond. 1909, pp. 335-350, 8 pis. Vide chapter x. p. 207. SHIPLEY, A. E. (1909). " The Tapeworms (Cestoda) of the Red Grouse (Lagopus scoticus)." Proc. Zool. Soc. Lond. 1909, pp. 351-363, 5 pis. Vide chapter xv. p. 334. WARTHIIT A. S. (1907). " Leukemia of the Common Fowl." Journ. Infect. Diseases, iv. p. 369. CHAPTER XIV OBSERVATIONS ON THE PARASITIC PROTOZOA OF THE RED GROUSE (LAGOPUS SCOTIGUS^ WITH A NOTE ON THE GROUSE FLY l By Dr H. B. Fantham INTRODUCTION IN the following paper are recorded observations made on the various parasitic protozoa found in Grouse examined in connection with the "Grouse Disease" Inquiry. Intro- The observations were, by force of circumstances, limited to one season, auction. an( j go ^ e accoun t s O f gome of the parasites are consequently incomplete. The parasitic protozoon of greatest economic importance, and to which most atten- tion had to be devoted, is Eimeria (Coccidium) avium, which is the pathogenic agent of a fatal disease in Grouse chicks, particularly prevalent in the spring and early summer. The morphology and life-history of Eimeria avium, and the results of experimental studies on Avian Coccidiosis are set forth in another part of the report. 2 The remaining protozoa found in Grouse may be conveniently divided into () parasites of the blood, (/3) parasites of the alimentary tract. So far I have found seven protozoa parasitic in Grouse, exclusive of the Coccidium already mentioned. (A) PARASITES FOUND IN THE BLOOD OF GROUSE. Sporozoa Hsemosporidia 1. LEUCOCYTOZOON LOVATI Seligmann and Sambon, 1907. This parasite was discovered in 1907 by Seligmann and Sambon in blood-films of Grouse. It was found in one bird not suffering from " Grouse Disease." Sambon Intro- (1 908-1909) refers again to the parasite, and states that he found it in five ductory. more Grouse. Sambon gives five drawings of the parasite. 1 Reprinted from the Proceedings of the Zoological Society of London, 1910. Vide chapter xi. pp. 235 and 252. 318 PLATE XLVI. LEUGOCYTOZC Opposite p. 319.] THE PARASITIC PROTOZOA OF THE RED GROUSE 319 Personally, I found this parasite in 1909 in three Grouse, all of which were in splendid condition, though in one case the spleen was found to be slightly enlarged. The parasites were in no case numerous, and in one bird only the younger stages of the parasite were seen. However, in the two remaining birds I had the good fortune to find the parasites alive in both peripheral blood and in heart-blood taken from birds freshly killed. Observations were made on the living parasites, both unstained and after colouring them intra vitam with methylene blue (Plate XLVIL, Figs. 17-22). The parasites were also seen while making blood-counts of the avian hosts, when the Leucocytozoon stained intra vitam with the methyl-violet of Toison's fluid. The nature of the host-cell is controversial, some authorities considering that it is an erythroblast, others that it is a leucocyte, while the views of some of the observers have changed during the course of their investigations. The Relation of host-cell clearly does not contain haemoglobin, and no melanin pigment is parasite to excreted by the parasite. The host-cell is at first round or ovoid, con- taining a rather broad and well-marked nucleus, and so the host-cell must be either a mononuclear leucocyte or an erythroblast. Possibly both these types of cells may be infected. The nature of the host-cell is inherently difficult to determine in view of the fact that all the blood-cells of birds are nucleated. Judging by the size of the nucleus of the host-cell (Plate XLVI., Figs. 1-3), I incline to the view that it is a small monouuclear leucocyte or potentially such. Other workers have acknow- ledged the resemblance of the host-cell to a mononuclear leucocyte. However, the matter can only be definitely settled by, researches on the origin and development of the various blood-cells of birds on which our present knowledge is meagre and contradictory running parallel with the researches on infected birds, studying the young stages of the leucocytozoon. The host-cell of L. lovati soon becomes drawn out at the ends, that is, the cell becomes spindle-shaped. This is probably due to a deformity of the cell brought about by the movements of the parasite within. Wenyon (1908) considers that some spindle-shaped cells occur normally in the blood of birds and reptiles. I have very rarely seen spindle-shaped cells in the blood of Grouse, though I have found spindle-shaped cells to be more numerous in the blood of fowl-chicks (cf. chapter xiii., Plate XLV., Fig. 18) dying from Coccidiosis. However, I would not suggest, on present evidence, that Coccidiosis is either directly or indirectly responsible for the appearance of spindle-cells in the blood. 320 THE GROUSE IN HEALTH AND IN DISEASE The presence of leucocytozoa does not always cause the body of the host-cell to become spindle-shaped. Matins and Leger (1909) found that the host-cell of Leucocytozoon caulleryi of the Tonkin fowl did not have its ends drawn out. They also considered that the host-cell was probably a mononuclear leucocyte. Personally, I have seen the spindle or horn-like end of the host-cell of L. lovati elongate during the movements of the parasite within it. Further, both ends usually are elongate (PL XLVII., Figs. 19-22), in other cases one end only becomes deformed (Fig. 18), while in a very few cases the cell contour has been largely un- affected by the parasite (Fig. 17). When both ends of the host-cell are affected, it not infrequently happens that the elongation of one end is greater than that of the other (PL XLVI., Figs. 4-6). The shape of the host-cell of different Leucocytozoa may be merely a reflex of the motility of the parasite within. It is not wise, therefore, to lay too great stress at present on the spindle-shape of the host-cells in diagnosing the Leucocytozoa of birds. The parasite in its younger stages is vermiform and like a Haemogregarine (PL XLVI., Figs. 1-3; PL XLVII., Figs. 17-22), and is more refractile in life than Morpho- the host-cell containing it. Young forms are by no means common, a >fS 2600 2900 2200 3000 1800 1600 1400 1300 1000 800 600 WO 1 \r * ' 200 10 YEARLY S YEARLY AVERAGE X NO SHOQTING MOOE MANAGEMENT 387 A chart is given on p. 386 showing the gradual improvement in results which has followed improved methods of management. It should be mentioned that the steady increase in the stock commenced about 1872, and that it was just before that date that close and constant heather - burning was first introduced. Carron Moor, Morayshire. A moor of about 3,000 acres, of which about 1,000 are flow ground, and the rest heather. The altitude ranges from 700 to 1,300 feet. Previous to 1897 the heather - burning had been neglected, in many parts it had grown to a height of 3 feet or more ; since that year the burning has been most carefully and thoroughly done, when possible. The heather all over the moor should continue to improve. The hill has only been regularly burnt for the last fourteen years, and during some of that time, owing to bad weather, little or no heather could be burnt. A considerable quantity of old heather still remains to be burnt, and much that has been burnt has not yet reached the most valuable stage. Good grit is abundant, and great attention has been paid to drainage. A moderate stock of sheep is carried on the ground. In 1910 the experiment was tried of introducing an artificial water-supply to the drier parts of the ground by means of dew pans. The results appear to have fully justified expectations ; in one case it was observed that five coveys were hatched in the immediate vicinity of a dew pan, where there were no young birds before. The results are conclusive so far as they go, but the experiment has not been continued long enough to admit of absolute certainty. The years 1907-1908-1909 yielded an average bag of 1,114 brace, as com- pared with an average bag of the years 1897-1898-1899, of only 241 brace, showing an increase of 873 brace. In 1910 the bag up to September 20th was upwards of l.,800 brace. No disease has occurred since this improvement began. From the evidence available, the Committee is satisfied that the whole of these birds are bred on the moor, and the theory that so large a bag can only be obtained by the immigration of birds from neighbouring moors is not supported by the evidence. The progress of the stock is carefully watched from the date of hatching to the commencement of the shooting season, and it is always found that the total bag corresponds to the prospects at the nesting season ; there are no berries on the ground to attract neighbouring 388 THE GROUSE IN HEALTH AND IN DISEASE CARRON MOOR MORAYSHIRE 3,OOO ACRES ANALYSIS OF BAGS 1897 -8 -9 1900 I9OI -2 -J -4 -5 6 -7 -8 -9 -/o Brace 1500 /45O 1400 1350 I3OO 1250 teoo I/5O IIOO IO50 1000 950 900 850 800 750 700 650 600 55O 50O 450 400 350 300 250 200 150 too 50 \ I J BAGS FIRST DWS DRIVING I st ofays driving 1897 44 BRACE 1898 93 1899 128 /900 373* I9OI 420 1902 326 1903 211% Yearly Bags r-j ^,_ fcX ^/ I 341 "-i 1 804 t 850 t 745 1 403% f rivng I9O4. 215 BRACE I9O5. .378 1906 4f4 I9O7.....7I5 I 908.. ..470'4> 1909. ...548 1910.... 946 Nearly Bags 350% BRACE, 778 861 1043 "'i 1500 MOOR MANAGEMENT 389 birds, and the first day's driving always takes place before any of the surround- ing moors are driven. Towards the end of the season there is often an immigration of birds from other moors ; but these visitors arrive after shooting has ceased for the season, with the exception of the gamekeeper's annual crusade against old cocks. The whole stock has been known to leave the moor in time of heavy snow, and to remain away till the snow has disappeared ; but such migrations have not been found to affect the number of birds on the ground at the next nesting season. The owner of the moor has drawn the following deductions from the foregoing facts : (1) That it is possible, by improving the heather, to raise the permanent stock of Grouse that a moor can carry without fear of disease developing locally, i.e., among the home stock of Grouse. (2) That drainage is very beneficial. (3) That an abundant supply of good grit is essential. (4) That Grouse driving is largely responsible for the increase. (5) That the limit has not necessarily been reached. (6) That the introduction of an artificial supply of water may be beneficial in a dry season or on the drier parts of the moor. Cawdor Moor. A very fine moor not yet fully developed or arrived at its full carrying power, with good young heather. The following points in the record should be noted : (1) The improvement in each decade. (2) A slight set-back in 1890 to 1900, probably due to the moor being less well cared for during that period. (3) The period 1900 to 1910 shows a marked advance, owing to regular driving and improved methods of management. (4) The time required for the moor to recover from the effect of the 1907 epidemic was one year; on all previous occasions it took upwards of four years to get back to the average yield. This moor is in the centre of a Grouse-bearing district, and will probably always be liable to disease from overcrowding by birds from higher and less well - burnt moors in late winter and early spring. This danger will remain 390 THE GROUSE IN HEALTH AND IN DISEASE CAWDOR MOOR -NAIRNSHIRE 30.000 ACRES ANALYSIS OF BAGS BffflCE 1860-61 65-69 70-74 75-79 80-84 85-89 90-94 95-99 00-04 1905-09 3000 2800 260O 24OO 2200 2000 1800 1600 WOO 1200 1000 800 600 400 00 i . \ \ NOTE. THE BAG IN 1910 UP TO 9 OCTOBER HAS 65/3 BRACE. 5 YEARLY AVERAGE MOOR MANAGEMENT 391 until some system is adopted for the proprietors taking joint action to regulate the stock in good Grouse years. From the examples that have been given four deductions can be made : (1) That it is possible by careful management to raise the permanent stock of Grouse on a moor, and do so without increasing the danger of infection beyond the power of resistance of the individual bird. (2) That during the various stages or periods of development of the carry- ing capacity of the moor there is a corresponding limit of stock which it is dangerous to come up to, and fatal to exceed. (3) That as far as yet ascertained the limit has not been arrived at on any moor beyond which a permanent increase of healthy stock is not possible by improved moor management. (4) That, though many moors by their proximity to less well -managed moors, and through the difficulty of getting the stock killed in a good year, immigration, abnormal seasonal conditions, etc., cannot entirely escape the ravages of disease, yet there is every reason to believe that the disease is both rarer, less hurtful in its incidence, and quicker to pass away on the well-managed than on the badly- burnt moors. CHAPTER XVIII HEATHER - BURNING By Lord Lovat THE student of the heather-burning question will be struck, from the very outset of his inquiry, by the curious fact that while all parties are agreed Variety of that there is the closest possible relation between the state of the tTheatfter! heather on any given moor and the health of the birds on that moor, burning, there is the greatest divergence of opinion, not only as to what are the best methods of burning, but even as to what are the special characteristics of a really well-burned moor. The vexed question of the relative values of autumn- and spring-burning, the percentage of a moor that it is advisable to burn in any given year, the effect on the heather of the presence or absence of sheep, the limit of sheep stock desirable, the proportion of long heather to be left for spring feeding or cover, the management of the steep slopes for winter feeding, the methods of burning patches, blocks or strips and the treatment of the various descriptions of moorland, all give scope for a much greater variety of opinion than the difference of local conditions appears to justify. In the previous chapter, the findings of the Grouse Committee have been discussed in relation to the various ideas which have been put forward as to the causes of disease ; in the present chapter it is proposed to discuss the practical steps that must be taken : (a) To raise the power of resistance of the Grouse ; (6) To lessen the risk of nematode and coccidian infection ; and (c) To compare these with the methods which have in the past been evolved from a priori reasoning. With these objects in view it is intended, in the first place, to trace briefly the history of moor management in the last century, to show how blind but 392 HEATHER - BUKNING 393 intelligent experiment has slowly been working its way towards comparative hygienic success ; to see where methods have failed through incorrect deductions from observations of natural phenomena ; to indicate broad lines of moor manage- ment in accordance with our present standard of krrowledge ; and lastly to lay down lines on which further experiments can be tried with reasonable prospects of success. In the early days of Grouse shooting, when shooting rents were low or non- existent, and the Grouse was an appanage of the sheep farm, not the History of main rent producer of a hill property, the moorland in the majority heather- of cases was burned by the farmer and his shepherds. The methods used were rough and ready, but effective. The object, as set out in the tack or lease, was to burn one-tenth of the moor ; the driest and most Heather windy days were chosen, and, provided the hirsels were burned formerly . i-i burned by approximately in the authorised proportions, the matter of a few acres sheep i . , , . . farmers. more or less in a single burning was not considered 01 much importance. Judging from occasional bags recorded it is probable that during this period the actual stock of Grouse throughout the country was often very considerable though the stocks were seldom fully shot and the recorded bags are so scanty that an exact comparison with the results of the present day is impossible. In the middle of the last century in England, and in Scotland a few years later, railway facilities, improvement in guns, increase of wealth, and, more than anything else, fashion, made the sporting value of the Grouse moor gradually approach the grazing value of the farm. The Grouse, up to then the occasional victim of the landlord and his friends, or of the poacher for the pot, became all at once a saleable article, for which there was, and has been since, an ever-increasing demand. The moor- Heather- Owner was quick to realise the enhanced possibilities of his property, burning transferred keepers were appointed to even the smallest acreage of heathland, togame- and the rights of burning the moor were transferred from the shepherd to the keeper, under the mistaken idea that the policy of burning to benefit Grouse, not sheep, would at once increase the yield of birds. It is a curious fact that, while the average man can predict with some degree of certainty the immediate result of any change in the existing order of things, the correct calculation of even secondary consequences requires the attention of brains of a very different calibre. When the landlords in their wisdom appointed the keeper to the role of moor-burner they achieved their 394 THE GROUSE IN HEALTH AND IN DISEASE immediate aim better cover for shooting over dogs ; but they gained also a second and not less noteworthy result, a drop both in the average bag IvGSU.lts, of Grouse, and in the grazing value of the hill-ground, a thing neither foreseen nor in any way desired. Founded on latter-day experience the reason for this is not far to seek. In the dogging days the long heather was the ideal. " Keepers' delight," applied to 3-foot heather, is still a recognised and but too often well justified term. The keeper, acting up to his lights and wishing to show the best sport on the Twelfth, not only stopped the shepherd from burning big stretches of heather, but stopped him from burning the heather at all. In books of sport in the year 1863 places are mentioned as splendid Grouse ground "fifteen hundred acres of heather without a single break ! " This method of heather culture was admirable for approaching wild birds ; in these jungles a covey once settled could be massacred at ease with "snap-hance" or breech-loader. Unfortunately, the change of methods was not equally satisfactory with regard to the health of the moor, and a very rude awakening was not far distant. A few lucky seasons, with a heavy crop of heather seed for food in winter and early ripening shoots in spring, gave in certain favoured districts an increase of bags by improving the conditions -for approaching the of "Grouse birds; then a cold summer followed by a winter with late spring; Disease." frosts, and a seasonal shortage of food intensified by an overplus of old stick heather, led to the inevitable result a general outbreak of disease. As early as 1857 there were reports of heather on certain moors "man high" by the sixties the whole effect of the shepherds' burning had passed away, Failure of an( ^ * n man y districts where the non-burning practice was at its height, grazing. nQ j. on ] v were there few birds and disease frequently recurrent, but the graziers' complaint became more and more common that there was not enough young heather and grass to feed the sheep-stock. At this periodt^the relations between sporting tenants and sheep-farmers became so strained that big sheep- farmers, then a well-to-do class, used in many districts to rent the shooting as well as the grazing of their holdings, and so get the control of heather-burning into their own hands. In 1871 and 1873 the Game Laws Commission investigated the relations of the sporting and farming interests, and some very interesting facts were elicited. Not the least important of these facts was the similarity of heather conditions required for sheep and for Grouse. This was brought out by the evidence of farmers HEATHER - BURNING 395 who had leased the sporting rights of their farms, and who spoke of doubling and trebling the bag of Grouse by burning tracts of ground in order to get the land back into the proper rotation for sheep, viz., one-tenth of the moor burned per annum. The reports of these and other successes obtained by heavy burning were not long in being spread abroad. Partly irom increase of knowledge, and partly to satisfy the sheep interest, more intelligent methods were pursued. On Change of many estates the principle was adopted "The shepherds light the P lic y- fire, the keepers put it out." As a principle rather than as a practical usage this is not far from the ideal. The shepherd wants the acreage burned for food, the keeper wishes the patch or strip method maintained for the segregation of birds. Matters in the early seventies were thus proceeding through the usual course of friction and inquiry towards mutual understanding and settlement, when in 1872 and 1873 the great disease year occurred. 1 Just as 1881, by the introduction of the Ground Game Act, may be described as the Jena of the rabbit, so for a very different reason 1872 and 1873 may be said to be the Austerlitz of the Grouse. From end to end of the Grouse area an epidemic created unparalleled destruction ; authorities realised that old methods must give place to new ones, and from that date the intelligent manage- ment of moors may be said to have commenced. Broadly speaking, we may divide the history of heather-burning into three periods, not always synchronous, but through which the majority of moors have passed at one time or another. 1800 to 1850, when the heather was burned by the shepherds in wide tracts, and one - tenth of the moor was fired every year without any attempt at scientific burning. During this period shooting rents were low. Large i st p er i d blocks of land were hired in Scotland for as many sovereigns as they now : fetch hundreds of pounds. The frequently quoted example of the sporting rights of the Island of Lewis, hired by Lord Malmesbury for a period of years for 25 per annum, is a case in point. At this time few moors were rented in England, and although Grouse driving had just begun in Yorkshire the results generally were not great, and the flint-lock, contemporary writers tell us, still had its devotees in the firing line ! Mr Snowie of Inverness was the only shooting agent for Scotland, and the names of moors for hire could be contained on a single sheet of foolscap. 1850 to 1873 marks the transition period of heather-burning. Moors generally 1 Vide vol. ii. Appendix I. 396 THE GROUSE IN HEALTH AND IN DISEASE were taken into the hands of owners and shooting tenants, the patch method 2nd Period f burning came into fashion, and the proportion burned, as far as lto1873 ' records show, dropped from one-tenth to one-hundredth part of the moor burned per annum. In this period great strides were made towards fitting out shootings with lodges, approach roads, and other conveniences. Large sums were paid out in the wilder and poorer districts, and a great deal of employment was given. Moors were let for sheep and Grouse at about the same figure. It is instructive to note that to-day on many of the same moors sporting rents represent five, in cases ten times the value of the grazing rents. The third period begins with the years of disaster 1872 and 1873, which were followed by four years of recovery and very restricted bags. These lean years were 3rd Period * ne immediate cause of the study of Grouse pathology. The investiga- I10- tion has continued more or less ever since, and after passing through the vicissitudes customary to research in a new field, has culminated in the comparatively extensive knowledge of the present day. Notwithstanding the fact that Cobbold had indicated in 1873 that the cause of the great outbreak was the Strongyle worm, the first move towards an im- proved system of management was not in the right direction. The moors had been indifferently burned so long that in order to catch up the rotation, recourse should have been had to big fires rather than to the patch or strip system of burning. This, however, was not realised. Many land-owners, seeing that "patch-burned" moors were less affected by the disease than moors on which no heather had been burned, jumped to the Burning in conclusion that it was the smallness of size of the individual patch, and Patches not the-total area of the burning that was all-important. This belief introduced. j g p reva i en t i n many localities to-day, and it is no exaggeration to say that to this error, more than to any other cause, is due the persistent recurrence of disease. From the foregoing history of past failures, and the knowledge scientific Conolu- investigation has given us, we can proceed to lay down with some approach to certainty the following rules of heather-burning, and the reasons on which they are based : (l) That, in order to maintain the vitality and therefore the power of resistance of the Grouse, the moor must be so burned as to keep the food-supply at its highest. HEATHER - BURNING 397 (2) That the early spring food-supply is the index of the carrying capacity of a moor, and that therefore heather - burning must be so ordered as to insure the maximum yield of food in February, March, April, and May. (3) That the patch or strip method of burning must as far as possible be pursued in order to segregate the birds, and thereby lessen the risk of infection by the Strongyle worm and the Coccidium. In discussing the question of burning for food two difficulties at once arise : (1) That of persuading the average moor -owner that by burning small patches with a small staff he cannot possibly get over his moor. (2) That of persuading him that at any time of the year the birds can be short of food, or that there is any real difference in the heather supply on well and on badly burned moors. To convince him of these facts it is necessary to go into figures, and those set out below may be taken as a reasonably accurate statement of foregoing conditions that obtain on many average if not model moors. On the ordinary 5,000 to 6,000 acre moor in England, and the correspond- ing 10,000 acre moor in Scotland, on which one thousand to one thousand five hundred brace are killed in a good average year, and area on which two keepers and one or more watchers are maintained, the average landlord thinks he is doing all that can be expected of him if, in " addition to the keepers, six to eight extra hands are employed in spring to burn the moor. Speaking generally, after a careful investigation of east and west coast conditions, of high and low moors, a good spring - burning season will give an average of ten whole days or twenty half days on which the hill can be fired. Taking into consideration dry and windy weather when the fire goes well but requires great control, and wetter conditions or less wind when the fire does not " run " so fast and may ^he managed by a couple of men, it may be calculated that on an average each keeper, dividing his gang to the best advantage (each gang consisting of not less than two parties), will not burn more than thirty, or at the very outside forty patches or strips in a full working day. That is to say, if the small patch or narrow strip method of burning is followed (i.e., burning in 398 THE GKOUSE IN HEALTH AND IN DISEASE areas of from one-eighth to half an acre), the two keepers and their parties will burn 20 acres a day, or a total of 200 acres of the moor in a year. Those who have not had a practical experience of heather-burning are apt to hold exaggerated ideas as to the amount of work that can be done in a single day's burning. It is only when facts and figures are subjected to a careful scrutiny, and the amount both of the day's work and the season's results are thoroughly gone into, that the smallness of the area burned becomes apparent. If we admit this contention to be correct, a little simple arithmetic will show that 200 acres on 6,000 acres of moorland is one-thirtieth of the total area, that is to say that, if the heather is regularly fired in rotation it will be thirty years, or in the case of the 10,000 acre moor fifty years old before it comes to its turn for burning. If we consider that every year is not a good burning year, and that on many moors on the west coast a good burning year occurs only once in three years, that some districts suffer from fogs, "haars," and mist; that others get so dried up after a continuance of east wind that it is dangerous to burn at all ; that in Scotland the high ground in a late spring is covered with snow until the end of March ; that there are the additional difficulties of suddenly rising winds, late dews, and of getting men away from their holdings, etc., it will be easily seen that a moor may go for a series of years with only one- sixtieth or one-hundredth part of its total area burned, and that instead of catching up the heather rotation in force when the sheep-farmer was responsible for maintaining it, many moors are steadily going back in their yield of young heather, and therefore in their power of maintaining a healthy stock of Grouse. The second difficulty, viz., of persuading the moor -owner that his birds Shortage ma 7 ^ e s ^ ort f food, is not less great. Many proprietors only see of food. their moors in August every head of heather in bloom and green shoots on every stem. He sees sheep grazing at the rate of one to the acre. It is very difficult to persuade him that at certain seasons there may not . be enough food for at least an equal number of Grouse. Let it be at once admitted that through the summer and autumn, even on the worst moors, there is abundance of food ; but then at that time, except for a previous infection, Grouse do not die. Let the doubter visit the moor in March, when the heather seed has fallen from the pod, when the young heather up to four and six years old is frosted a clarety red or brown colour, when the old stick heather sparsely distributed and bare of side shoots does not carry a HEATHER - BURNING 399 " canopy " with which to keep out the withering effect of the cold winds and frost, and he will find a very different state of affairs. Careful examination will show that the close-growing six- to fifteen-year-old heather with a thick matted covering affords the only feeding at this time of year, and that even here the shoots are green, not at the top, but- half way down the stem, where they are protected from the cold. It is at this time that the real test of moor management is seen, and a little careful study will prove to demonstration certain facts not found in the philosophy of the "small patch" enthusiast. Granted the premises set out above, The test of it follows that, if the moor is being worked on a hundred years' ^anage- rotation, the total amount of spring - feeding heather, that is to ment - say, the amount that lies between six and fifteen years of age, is roughly 9 per cent, of the total area of the moor. If the moor is burned on a fifty years' rotation, which is the rotation of the majority of moors to-day, the amount is 18 per cent, of the total area. If, however, the heather is burned on a fifteen years' rotation, the rotation the Committee advise, the amount of edible heather represents nine years out of a total of fifteen, i.e., 60 per cent, of the total acreage of the moor. That is to say, if we admit the early spring months to be the critical time in the life history of the Grouse no great admission seeing that it is in spring that disease invariably appears we shall realise that a well-burned moor can carry seven and a half times the stock of the moor burned on a hundred years' rotation, and nearly four times as much as that of the average moderately burned moor. These figures may possibly be challenged ; but with regard to the area burned the proof is perfectly simple. Employ a surveyor to measure up the patches of a strip or patch-burned moor, burned in 1910 a very good burning year compare the acreage with the total area ; the result will astonish many landlords who habitually boast that they burn one-tenth of their moor every year. It will perhaps be argued that the* six- to fifteen - year heather is not the only spring feed, that even the stout stick heather will present occasional green shoots, and therefore afford some small measure of sustenance to the Grouse in the spring-time. This is true, and it is a fact that, faute de mieux, Grouse are able to exist on an unburned moor. It must, however, be More food remembered that they require probably twice or three times as much required in of the sapless, partly dried-up heather of April as they do of the more succulent shoots of summer and autumn. The weights of crop contents show that 400 THE GROUSE IN HEALTH AND IN DISEASE late winter and early spring up to two hundred and fifty grains of heather are found in the average afternoon crop as against fifty grains at any other time of the year. It is therefore reasonable to say that as the Grouse have to increase the amount of their food they will naturally go to those places where edible Calluna is most readily obtained, and thus by congestion of the stock on a small area will not only over-crop the food there, but also, as will be shown later, will be exposed to an increase of infection by the nematode worm and by the Coccidium. Before leaving the question of the comparison of feeding areas of well and badly burned moors, one further point should be mentioned. On a well-managed Heather moor the heather fired is all under twenty years old, and when it is should be b urne d the young heather springs from the root the same year. On a young. badly burned moor, where old stick heather forms the main crop, the heather springs from seed, 1 and in many cases only affords food for Grouse after the area burned hy,s passed through successive stages of grass and cross- leaved heather varying in point of time from six to twenty years. If the soil has a tendency to grow bracken the heather may be lost for ever. That is to say, in a fifty years' rotation moor, probably 20 per cent, of the moor is either black ground, bracken, grass, or cross-leaved heather, and is not yielding its proportionate quota of food. When we consider this loss of food area as well as the generally recognised fact that on a frequently burned moor the heather grows thicker and more luxuriantly than on one badly burned, it is no exaggeration to say that the food-bearing capacity of a moor at its best and worst is as ten to one. This change in the flora of a moor after burning is specially noticeable in the case of accidental fires, such as occurred on a large scale in York- shire in 1887 and 1893. Accidental fires are commonest in very dry weather, and thus there is a danger of the peat and soil being burned to a depth of several feet, thus destroying the roots of the heather. The second reason for burning is to keep the birds at all seasons split up over the ground. Grouse are not naturally gregarious, nevertheless they frequently get together into big packs for purposes of safety after frequent disturbance, or for shelter on the approach of storms, or in search of food, or to avoid snow or drought, or to prepare for migration, but, once the immediate cause of packing is removed, their instinct is to get away from their brethren and take up their family life apart. To help the birds to develop this instinct, 1 Vide PI. LVII. Fig. 2. PLATE LVII. FIG. 1. Calluna vulgarls (Common Heather or Ling). Showing form of plant when growing from the root first year's growth. . 2. t'litltniii i-iili/tii-ix (Common Heather or Ling Showing form of plant when growing from seed. Opposite p. 101. J HEATHER - BURNING 401 the patch or strip method has been advocated in the past, and, provided always the strips and patches in their totality suffice to maintain the food gtri g and yield of the moor at its highest, no better system could be adopted, P** * 168 - The minor point of whether narrow strips or square patches are advisable is not worth discussing; keepers have their fancies, self-appointed authorities will air their views ; it is probable that both methods can be used with effect, each to suit the special circumstances of individual moors. The object to be aimed at is clear, that every bird should have its tufts to nest in at the -edges of the burned ground, its bare ground to sun itself in and on to which to take out its chicks ; its older heather for concealment, its breast-high 10- inch heather for feed, 'its well-matured heather for seed and shelter in winter, and, finally and of most importance, its six- to fifteen-year-old heather to keep it in health and vigour in early spring. In cases where it is impossible through the wetness of the season, shortness of labour supply, etc., to get the moor thoroughly burned in strips or patches, it may be asked whether it is not better to abandon the small patch system and burn a large acreage of moor ? The answer can be given with no uncertain voice patches are only a secondary consideration, the first essential is to get the proper proportion of the total acreage of the moor burned each year. Apart from the destruction of Strongyle larvse by fire it must never be forgotten that it is the sufficiency of the food supply that enables birds to stand a heavier infection of this parasite. On Broomhead and Moy moors, which carry regularly the highest stock per acre and are among the best burned moors in England and Scotland respectively, the patches burned are large and disease is practically unknown ; but so also is stick heather ! Having laid down the reasons with regard to food supply which make heather burning necessary, the next thing is to consider the various Methods of qualities of soil and heather into which a moor is divided, discuss burnin g- the treatment of each and look into the limitations, some natural and some artificial, which stand in the way of a complete realisation of the object in view. Old heather should be burned in strips, for when old stick heather is burned the fire is so hot that the roots are charred and killed ; in Old this case regeneration can only proceed from seed, and if the burned heather - areas are narrow, self-seeding is materially helped by wind-blown seed. VOL. I. 2 c 402 THE GROUSE IN HEALTH AND IN DISEASE While it is necessary to burn off blocks of old heather in strips, it is advisable at the same time to get a considerable area burned on one beat of the moor. Sheep always rush to the newly burned ground for the sweeter grasses that grow there, and unless there are good stretches of burned ground for Danger them to feed on, they will concentrate on the small isolated patches from sheep. an( j p u jj U p a ^ ^he young heather plants as they spring from seed. Every one who is acquainted with a moor in autumn must have observed the hundreds of little brown shrivelled-up heather seedlings pulled up by the sheep's teeth on every patch of newly burned ground. 1 To obviate this wholesale destruction it is sometimes considered advisable, where the sheep stock is heavy and the moor has a tendency to go back to grass, to fence off areas of old stick heather for two or three years after burning. This gives the young heather a chance of coming away, and once rooted it can defy the efforts of the stoutest-toothed "black-face." Old heather should, whenever it is possible, be burned " against the grain," Burning that ^ s * Sa 7> a g a i ns t the lie of the heather sticks. " Back-firing " 'against^ or |j urn i n g against the wind gives a very clean burn, the fire travels slowly, and destroys not only a larger percentage of the stalks of the heather, but also burns into the "fog" or moss which surrounds the roots of old stick heather. Owing to the shortness of the time available for burning in an average year, dampness of the soil, etc., "back-firing" is not always possible. In the case where an overcrop of partly charred sticks have been left it is advisable to run a fire through the burned ground a second time if possible in the second or third year following the first burn. This Second second firing has the effect of clearing the ground of the charred burning, heather sticks and burning off the moss which, having been exposed to the air, is drier than at the first time of kindling. This affords a good clear seed - bed on which the wind - borne heather - seeds rapidly establish themselves. The very greatest care must be taken of steep banks, especially those _,,. , facing south, as these are the places that in time of snow give shelter Steep faces. and food to the Grouse. It must be understood that careful treatment does not mean allowing such places to run into old stick heather. Many keepers are so frightened of touching these winter feeding - places that on many moors the heather in these places has become rank, and is 1 Vide PI. LVII., Fig. 2. * Vide chap. xxii. p. 501. HEATHER - BURNING 403 rapidly losing its value as winter food. Burning on steep banks should be carefully done so as never to reduce the total yield below the minimum which is necessary for food in time of snow. In the interest of both sheep and Grouse wet " flow " l ground should be burned in big stretches outside the ordinary rotation if possible once p-] ow in every six years. Flow ground usually overlies deep, damp peat, and s round - is therefore protected from the full effects of the fire ; the grass and the stunted heather in consequence come away quickly from the root. It is often difficult to burn flow ground owing to the heather being broken up into tussocks, and the driest weather should be chosen for the task. Knolls and hillocks are the favourite haunts of the Grouse, and however small they are, never more than one - third should be burned at one time ; T 11 the keeper's aim should be to provide in this way both food and cover for the birds frequenting them. The keeper should invariably get at the northern slopes of his ground as soon as the opportunity occurs. On high moors late snows North make this possible only once in half a dozen years. hilk Grey heather killed by snow or frost should be burned wherever it appears ; it is absolutely useless for food, and serves no purpose beyond cumbering the ground. Probably also heather which has been damaged by beetle should always be burned, as it is very doubtful whether it ever recovers from the attack of this pest. Peat hags should be burned when the ground is not too dry. Grouse are particularly fond of broken peat ground, and the food supply of short gnarled heather that grows there should be maintained at its highest. The Peat peat itself occasionally gets on fire, and has been known on occasion Hags- to burn right down to the bed rock. In one or two cases that have come to the Committee's notice excellent heather has grown on the mineral soil thus exposed. As the new growth in such cases may take twenty or thirty years to come up, such burning is probably outside the rotation that even the most progressive of moor-owners would care to adopt. 1 By " flow " ground is meant the flat stretches of peaty land where, owing to the retentive nature of the soil, the surface water lies in pools and channels between tufts or tussocks of heather ; it is to be distinguished from marshy or boggy land where the water lies in suspension below the surface. Flow ground cannot as a rule be drained owing to the absence of a natural " fall," and even when drains are cut the nature of the soil is not sufficiently porous to make them effective. Flow ground grows a poor quality of stunted heather usually mixed with sour -looking grass, yet Grouse are often found to frequent it during the daytime, especially when it lies on a high plateau or immediately under the crest of a ridge. 404 THE GROUSE IN HEALTH AND IN DISEASE The sides of burns and streams are most important features on a moor ; they are the favourite nesting places of Grouse, they afford shelter during storms, Bums and anc ^ are places where food can be obtained in times of snow. They streams. should be carefully burned in very small patches, special care being taken to clear up the immediate burn - side and prevent its being used as a shelter for vermin, particularly for stoats, who otherwise use it as a convenient covered way to reach their prey. It is hardly necessary to point out that in burning a moor the keeper Burning must consider the method in which the shooting is carried out. In the for sport. cage Q f jj e driving moor broad belts should be burned immediately in the rear and patches immediately in front of the butts to facilitate the "picking up " of Grouse ; settling ground with good cover should be left in the direction towards which it is intended to drive the birds. In the case of " dogging " moors, favourite banks should have a special allowance of long heather into which the birds can be worked at the end of the day. In deer forests " the beds " on which deer lie on in the sheltered corries should be lightly burned. Heather can be burned at all times of the year in England. In Scotland, by statute, heather-burning is confined to the period from November Limitation ' of heather- 1st to April 10th. On high wet moors an extension of the period to burning. April 25th can be obtained. In Wales, by custom, burning is usually carried on during the spring months. As soon as it was established that the health of the Grouse depended not only on the distribution of edible heather, but also on the total extent of the Autumn- su pply> ^ became a matter of primary interest to the Committee to bummg. ^ ec i(j e whether in their opinion the burning season should be extended, and how the results of autumn- and spring-burning were to be compared. The investigation was begun by sending an inquiry-paper to correspondents, asking for their experiences of autumn-burning ; the time taken for heather to grow again when springing from the root and from seed respectively ; the opinion of sheep farmers as to the merits of the two methods and the character of soil least and most suitable for autumn-burning, based on a comparison of results obtained. In neighbourhoods where heather had never been regularly burned in autumn, correspondents were asked to burn patches in spring and autumn side by side and to compare the results. The idea was intelligently taken up and thoroughly worked out, from the south of Wales to the north of the Highlands. HEATHER - BURNING 405 The results of the observations taken have brought the Committee to the following conclusions : (1) That in the interests of sheep and Grouse autumn-burning is advisable on all moors. (2) That it is necessary on large moors. (3) That it is the only possible method of getting high ground with a northern exposure into a proper rotation of heather crop. The Committee are further of opinion : () That in the North of England the evidence goes to show that, whether springing from the root or from the seed, the growth of heather following autumn- and spring-burning is identical. (6) That on the more northern moors the heather is probably slightly slower in reaching maturity after autumn-burning, especially on shallow peat or hard ground. (c) That, while there is a certain prejudice, especially amongst older keepers, against autumn-burning, this prejudice did not appear to be founded on substantial grounds ; as far as the Committee were able to learn, the majority of those who expressed themselves opposed to autumn- burning were found on examination not to have themselves tried it, and to have based their opinion either on general reasons or second- hand information. (d) That on 95 per cent, of the moors in England on which autumn-burning had been tried the practice had been continued with the full sanction and approval of the sheep farmers interested. (e) That at least 75 per cent, of the larger moors examined are insufficiently burned, and that in many cases an extension of the burning period would enable a larger stock of both sheep and Grouse to be maintained. (/) That autumn- burning is necessary in the interests of the health of the Grouse and sheep, and that legislation in Scotland making it per- missible to burn after October 1st should be introduced into Parlia- ment without delay. With a view to further ascertaining the opinions of sheep-farmers on the subject of heather-burning, a meeting was arranged between repre- sentatives of the Committee and a number of sheep-farmers from different sheep- districts. The views expressed clearly indicated that in the opinion of sheep-farmers there is not enough heather burned for either Grouse or sheep 406 THE GROUSE IN HEALTH AND IN DISEASE on the majority of moors in England and Scotland, and that there is a general wish on the part of sheep-farmers on heather ground that more heather should be burned. The farmers further stated that they would be glad to try autumn- burning in co-operation with owners, and that they could probably give more assistance in the autumn than in the spring, because in the spring they are usually busy with sheep that have returned from wintering, and with the superintendence of their stock during the lambing season. They considered that it matters little whether autumn-burned heather grows as well as spring-burned heather, the great object being to get rid of the large tracts of old useless heather which are of no value either for Grouse or sheep. They confirmed the view of the Committee that high ground with a northern exposure can only be burned in the spring in very exceptional years. The sheep-farmers further drew attention to the following points : (1) That where heather is allowed to grow too old, there is a danger of its place being taken by bracken after burning, whereas if the heather is burned young the fresh growth has more vitality and usually defeats the bracken. (2) That old heather is undesirable because after burning many " burrens " or bare sticks are left which tear the wool off the sheep's bellies. (3) That sheep-farmers prefer the heather to be burned in large patches, because otherwise a large enough area is not burned each year ; but that they have no objection to burning in small patches and strips, provided the total area burned reaches the full proportion proper to the moor. This proportion was estimated at from one-ninth to one-twelfth of the total acreage. On the actual methods of carrying out the burning there is not much to be said. The gear is simple ; a birch broom and a paraffin firing lamp. 1 The Methods of necessary party of six or eight men under a keeper can work in pairs prc Ire- on a calm day with a fairly dry moor, the keeper starting the fire, the couples guiding its course, extinguishing and controlling it as occasion demands. In windy weather, or when the heather gets dry, the whole party have to act together, and in consequence, though the individual burning may be done at a quicker rate, a smaller total area will be got through in a day. As a health-giving exercise heather-burning has much to commend it ; it is particularly hard work and trying to clothes, temper, and especially to the eyes. 1 Special lamps are sold for the purpose. HEATHER - BURNING 407 The Committee have now laid down the object of heather-burning, the methods of treatment of different types of ground and certain laws applicable to all moors ; it only remains to discuss the practical steps the owner p rac t; ca i of a badly burned moor must take to get his helither-land into " good steps- heart " with the least possible delay. ' We will presume for the moment that the moor under consideration is one of those many moors in England or Scotland which has possibilities, but which has been neglected ; a moor which has its high ground difficult to burn, its boggy undrained land, and its stretches of stick heather with a tendency to revert to grass ; that, moreover, it is a moor which has disease at irregular intervals as well as average and bumper years ; and that, like all moors that form part of a tract of Grouse ground, it is liable to be over- stocked at the critical period of late winter and early spring. The first thing that the owner of a moor of this sort must do is to decide what rotation of heather crop is to be aimed at, i.e., what is the total choice of area of moorland available, and how many acres of it are to be burned rotatlon - every year. The period of rotation requires very careful consideration, and depends on the average age of the heather, the sporting results the moor-owner wishes to obtain during the period of transition from bad conditions to good, and the local difficulties labour, climate, etc. From what has been stated on the results of burning stick heather, it is evident that if really old heather bulks largely in the total area it is impracticable to jump at once into a fifteen years' rotation and maintain any stock of Grouse. A little calculation will show that in the extreme case of a moor on which all the heather has reached the " keeper's delight " stage, and therefore requires six to twenty years to come again, to burn the whole moor in fifteen years would leave not only no spring feed, but scarcely any edible heather at all. In treating a really badly burned moor, therefore, unless it is determined to sacrifice several years of sport and set all the old heather ablaze, less heroic methods should be adopted, and the ground be got gradually into a shortened period of rotation. To fix how long this intermediate period should be, it is necessary to go carefully over the burned ground of the last decade in order to see how long the general average of burned heather takes to come to maturity. This will vary, not only with the age of the heather, but with the elevation of the moor, the climate and exposure, the depth of peat, the amount of flow and hard ground, and the stock of sheep. By carefully noting the results and 408 THE GROUSE IN HEALTH AND IN DISEASE comparing them with similar results on well-burned moors, it will be possible to arrive at sufficient data to give the number of years for the first rotation. It is probably generally true to say that on a moor on which heather grows readily, and on which all the heather is burned before it has passed its best, heather springs from the root the year it is burned, and comes into flower sometimes in the first and generally in the second or third year. That on a badly burned moor situated 600 to 1,200 feet above sea-level the ground covered by partly withered heather of an average height of 2 feet will remain black for two years after burning, that for the next three to five years it will be covered by grass and cross-leaved heather, and that six further years will be necessary before there is a full yield of edible Calluna heather. This will mean a handicap of nine years, and on a moor of this sort a rotation of twenty to twenty-five years should, in the first case, be attempted. It must not be thought that for the whole of these nine years the ground is useless. During that period it is useful for old birds as a basking-ground, and for young chicks as a feeding-ground ; and the early grasses and seeds and even ferns that grow there are not without value. It will afford, however, little or no spring food. Having fixed the rotation and the acreage to be burned, the next thing is to decide on the allocation and size of the individual patches or strips. We will Size of suppose that the badly burned moor is one of 4,000 acres, that there is a patches. sufficient labour supply, and that the rotation attempted is to be one of twenty years (i.e., one-twentieth of the heather ground burned per annum). The amount to be burned every year would be 200 acres ; but to make up for bad burning seasons 300 acres should be attempted whenever seasonal conditions permit. To burn this area in patches of one eighth or one fourth of an acre is obviously impracticable; even allowing for an area of 50 to 100 acres being burned in big blocks (flow ground or high ground with a northern exposure), it would be impossible to burn the remaining twelve hundred odd strips necessary to make up the total acreage prescribed. It is therefore necessary to decide on certain general lines of moor-burning which will give the necessary total area burned, and still maintain the patch system as far as possible. This will be obtained by treating each type of heather on its own merits. Example of 1st. To burn old heather in strips 50 yards wide , and let the strip run as far as the fire will take it. HEATHER - BURNING 409 2nd. To burn average foot and a half heather in strips and patches of one fourth to one half of an acre. 3rd. To burn patches and strips on the steep faces of the wintering ground in small blocks of not more than one fourth to one tenth of an acre each. 4th. To burn the burn-sides, knolls and nesting grounds of Grouse, in even smaller plots. 5th. To burn the wet flow ground in big patches of 1 to J.O acres. (N.B. This should be done so as to cover the flow ground every six to nine years.) 6th. To burn the high ground with a northern exposure in large 3 acre blocks. 7th. To burn good broad strips round each of the boundaries. 8th. To treat specially those portions of the moor which have a tendency to revert to grass. By adopting these methods with, say, three keepers (watchers to count as keepers), each in charge of two parties of two or three men each a total of from fifteen to twenty-one burners it may be possible to get the work done. The burners will have to fire twenty patches of 1 to 5 acres, say a total area of 50 acres, 300 patches of from one fourth of an acre to one acre, making, say, 150 acres, two hundred patches of from one fourth to one tenth of an acre, say 50 acres, i.e., about 500 burns with a total of between 250 and 300 acres. Taking the average as four parties burning a day, for it must be borne in mind that on very dry or windy days the keepers will often have to use the whole of their posse as one burning party, it will require about ten days or twenty half days to get through the work, calculating that each party burns an average of fourteen patches a day. This is a fair statement of what ought to be done on a 4,000-acre moor ; it probably exceeds by a very considerable amount what is done on many moors of double that size. If the number of men for the burning parties cannot be got the area of the fires must be bigger ; but the ratio of heather burned to total area of the moor must be maintained at all costs. In considering the general question of heather burning, undue Arguments weight must not be attached to arguments such as the following : tensive 6 * (1) That the expense is too great. burning. 410 THE GROUSE IN HEALTH AND IN DISEASE Apart from the question of sport, this argument can be proved to be erroneous in mere pounds, shillings, and pence, for, as has been shown already, moors can be raised from a yield of under three hundred brace per annum to over three thousand, or, expressed in terms of existing values, from 300 a year to not less than 3,000. Even on moors where such great advances cannot be ma,de, the avoidance of a single year of disease would alone save more than three times the expenditure incurred in a decade through the employment of a few extra men for burning. (2) The argument that the old keeper frequently puts fonvard that " to strip the moor is sufficient." It is not necessary to deal with this point again ; it is sufficient here to point out that keepers have not the least idea of what acreage they burn in a year, and will often say and believe that they burn one-tenth part of the moor when one-hundredth is nearer the mark. (3) The argument that the existing method of burning has produced good results in the past. This must be accepted, but with the reservation that good results in the past have almost invariably been followed by disease in the following year. It is to avoid disease and heighten the average yield of the moor that the progressive landlord will see that it is worth while to limit the food crop for a few years in the attempt to get the moor into good " heart." (4) The old-heather argument that it is dangerous to burn the old heather as birds will have no food in winter. Three things should be remembered in this connection. 1st. That on some of the most heavily stocked Grouse moors no old heather exists, yet there is enough winter food. 2nd. That in time of snow the medium-sized heather can be raked with little labour and thus afford abundant winter food should the bulk of the long heather be buried in snow or destroyed by frost. 3rd. That long heather is valuable only as long as it gives food Grouse eat heather shoots, not wood. Much of the heather in England and Scotland that has been left for winter food has been steadily going back for twenty years, and it now produces barely one-tenth of its proper food yield. HEATHER - BURNING 411 (5) In a good burning year keepers often wish to knock off "work" under the plea that enough burning has been done for a single season. It is very doubtful if too much burning can ever be done in any season provided the areas of the fires are reduced in size as the patching and stripping of the moor progresses. By large fires a moor can be easily burned out, but no old patch is so small that a smaller patch cannot be taken out of it and the moor be thereby improved. Certain moors or portions of moors have a tendency to go back to grass, and therefore require special treatment. The most common reasons for Treatment this reversion from heather to grass is lack of attention during the of green ground. period from 1850 to 1900, overstocking by sheep (especially of the black-faced variety), and big fires after the heather has got old. In practice it is found that these causes often work in combination. The attention of gamekeepers should be directed to the burning of " white grass " as well as heather. By doing so they provide directly for the sheep and indirectly also for the Grouse ; for, so long as they are plentifully supplied with grass, sheep will not draw heavily on the heather. "White grass" can be burned in larger stretches and consequently more rapidly than heather, and advantage should always be taken of any specially dry season to burn the low, damp hollows where this grass chiefly abounds ; in four seasons out of five such places are too damp to burn. To bring green ground back to heather is always a slow and often a costly business. Control of the sheep stock to prevent an over-cropping of the heather seedlings, fencing of the newly-burned patches, sowing of heather seed in specially prepared ground are all methods that may be found useful. The methods of procedure and the respective values of " green " ground for sheep and Grouse are discussed at some length on p. 499. The laisser faire argument that the change from heather to grass or bracken depends on the seasons, and that nothing should be done is one that the Committee view with suspicion. Putting off burning where old heather exists only means putting off the evil day, and it is probably correct to say that for every year that the old heather is left unburned after maturity, at least one year is added to the time required for the young heather to replace the grass. There can, unfortunately, be no doubt that bracken is spreading considerably 412 THE GROUSE IN HEALTH AND IN DISEASE on very many moors in the south and west of Scotland, and that not much effort is being made to combat this pest. Thick bracken will rapidly destroy both grass and heather, but of the two it is probable that the heather will be the more easily destroyed, and if bracken has once taken possession of ground for a period of years it will be found, on clearing the ground by regular cutting, that grass will probably come where heather formerly flourished. It is a common experience, when burning fairly old heather, to find that the few bracken stems which existed among the heather give rise to a much thicker crop on the bare ground, and may entirely choke the fresh growth of young heather. Despite most careful investigation by the Highland and Agricultural Society, and other interested bodies, no specific has yet been discovered to cure the bracken trouble. 1 In the course of their investigations the Committee have noticed that bracken very seldom grows on crofter "soumings" where there are many ponies. While they do not feel that they have enough evidence on the subject to claim that this is a solution, they mention the fact as one which may be worth further inquiry and experiment. In considering the general question of heather-burning, blaeberry ground has been dealt with as heather ground, and its further treatment need not be gone into in any detail. It is unfortunate that sheep are specially fond of the blaeberry plant in its younger stages, and on moors carrying a heavy stock of sheep this valuable plant is often grazed down to the root. Grouse eat blaeberries (buds, leaves, and berries) with avidity ; even the caterpillars that infest the plant in early summer are a source of food-supply for young birds. It may be noted from an examination of the tables of crop-contents that the consumption of blaeberry by the Grouse is irregular, and the percentage seems to depend more on the general supply of food than on any tendency of the birds to eat the plant more in one month than another. From statistics collected, blaeberries appear to form 30 per cent, of all the foods taken by the Grouse in Derbyshire ; 22 per cent, in Yorkshire ; and 11 per cent, in some of the counties of Scotland. Undoubtedly a good deal could be done to increase the food-yield of the moor by encouraging the growth of this hardy plant, either by fencing off areas where it is eaten down by sheep or by planting it in suitable places. Colonel G. J. Fergusson-Buchanan of Auchentorbi has recently printed a pamphlet setting forth the success which has attended his efforts to get rid of bracken on heather and grass land. HEATHER - BURNING 413 DRAINING. Close observers of " Grouse Disease " have always held the idea that the mortality has been in some way connected with the wet, undrained portions of the moor. Scientific investigation shows that there is probably a good deal of truth in this view. The Strongyle larvae have been shown to pass the free- living portions of their lives in damp surroundings. Even in frozen water they appear to live for an indefinite period, whereas complete drought may kill them in a very short time. Without putting drainage forward as an absolute specific against disease, it can be urged with confidence that a well-drained moor is less liable to dangerous infection of nematode worms than a moor with stagnant pools and great stretches of flow ground. Draining should be done with care and on a well-considered plan. 'Nothing is more common than to see the water carefully drained from the top of a hill-face descending only to flood a much larger acreage below, owing to there being insufficient drainage arrangements for carrying off the surface water thus collected. It will generally be found advisable to employ a professional sheep-drainer and allow him to work by contract at a fixed price per chain. The specifications must ensure that the drain is clear cut, at least the breadth of a spade at the bottom, that the sides are at a slope of not more than one in two, and that the turf dug out is thrown away not less than 6 feet from the drain. Shallow drains made in this way reduce the danger to the young Grouse, and are also less liable to choke and flood the moor. Drains should be made on the herring-bone pattern, and begin with wide arms high up the hill-face to catch the surface water. Special care must be taken that the central drains are sufficiently large to allow the water collected to run off easily into a main burn. The ground that it is desirable to drain is not the flat sodden bog or sour flow land, but the ground on which the fog or moss has only recently begun to choke the heather. Draining, when undertaken, should be thorough. It is better to confine the area of work and watch results, with an occasional clearing of the drains, than to spread the work over a great extent of country where little immediate result is seen, no attention is paid to upkeep, and the lie of the drains is soon lost. On most moors money would be well expended in draining, for not only would the risk of infection be thereby lessened but the total yield of heather would be increased. The supply of grit which drain-making is apt to expose is not a trifling consideration to the general health of a moor, as will be seen in chapter v. CHAPTER XIX THE HEATHER BEETLE By Percy H. Grimshaw Part I. On "Frosted" Heather and its Connection with the Heather Beetle, Lochmsea suturalis. FOR a long time the attention of many proprietors of Grouse moors and their keepers has been directed to the fact that large patches of heather, varying in size from a few yards square to hundreds, or even thousands, of acres, have turned a rusty red or withered grey colour, and have become useless as food for Grouse. In the districts which suffered most from this condition large numbers of the Grouse have left the affected area and migrated to neighbouring moors where the heather was in a healthy state. Not only does the shooting value of such a moor become thus seriously impaired, but the health of the birds themselves is affected. Although there does not as yet appear to be any direct connection between the diseased state of the heather and " Grouse Disease," inasmuch as the birds have been proved not to eat the withered shoots, yet the deficiency of food on an affected moor undoubtedly results in a weak state of health, rendering the Grouse less fit to resist the attacks of tapeworms and other parasites, or to combat disease of any kind whatsoever. It is, therefore, of the utmost importance to ascertain, if possible, the exact cause of this blighted condition of the heather, and to devise some practical remedy. During the progress of this Inquiry many letters have been received by the Committee which serve to show the great extent of heather affected in various parts of the country. Diseased heather has been reported from moors in the counties of Nairn, Perth, Inverness, Argyll, Ayr, Lanark, Kirkcudbright, Dumfries, Selkirk, Roxburgh, Fife, Cumberland, Yorkshire, and Montgomery. 414 THE HEATHER BEETLE 415 From this list it will be noted that the blight has been met with principally in the western districts ; but this may be due to lack of information from the east, and it is hardly advisable at present to lay much stress upon the distribution of "frosted" heather as indicated- by this correspondence alone. The following extracts from th,e correspondence may be interesting as indicating what has hitherto been observed with regard to the extent and nature of the ground affected, the time of year when it is chiefly noticeable, and other points. The names of localities, and those of the proprietors and keepers have, for obvious reasons, been suppressed ; but at the same time the Committee would here express their indebtedness to all who have thus contributed information. (a) " Diseased heather ' an acre in extent.' " (6) "First noticed about the end of August last. ... As there was no frost at the time, it struck the keeper and myself as somewhat curious." (c) "(1) The rusty red is from ground which has become affected since last October ; (2) The dark grey piece is from ground which was attacked two years ago." (d) " There are great areas, and many patches, of this brown, withered heather on the moor." (e) "I am sending two samples of heather for your inspection. I am sending one of young heather, which has turned quite white and withered looking, and is growing on the side of a hill facing the south-east. The other sample is off a large stretch of level, wet, mossy land. It seems to grow till a certain height, and then to die away." (/) " There are several patches of considerable extent over the whole moor, which look similar to the part off which I took the heather I sent you for examination. Should the disease spread to any great extent, it might become damaging to the feed of the Grouse. ... I have seen no heather affected which is under five years old ; all parts affected are from six years upwards." (g) "There is far more rotten heather on the low moors at this season than there was when I wrote to Mr , and on an adjoining property it was very bad this season, while it was almost unknown a couple of seasons ago. In my opinion this spoilt heather will prove a very serious question in the near future for the proprietors and tenants of Grouse moors." (h) " My keeper says it [i.e., diseased heather] was confined to the young heather, and the old was not frosted at all. Also the west end of the moor, 416 THE GROUSE IN HEALTH AND IN DISEASE about 2,000 acres, was bad with it ; and there was none on the remainder of the moor." (i) "I have forwarded to your address a sample of heather that showed signs of being frosted in July last year. It turned a rusty red, and some of it grey between July 8th and 24th. It was on the latter date that I noticed it there would be nearly 2 acres in the patch affected." (j) " The damage done on my own estate was not very serious, but in neighbouring places it was muck worse. . . . With regard to the permanency of the damage, I do not think there is much fear. I examined some of the ground as recently as yesterday, and find that even where it has the withered grey look, the twigs are green under the bark ; only in a few cases is the previous season's growth dead, and in no case is the two-year-old growth destroyed. ... I should have stated above that the damage has only occurred where the ground was very cold, wet, and waterlogged the sort of ground on which, even when drained, it is useless to plant forest trees." (k) "We think the damage is chiefly, if not entirely, confined to places where the sun strikes during the day, and especially in the morning. . . . My ground faces chiefly north-west and west." (1) "With regard to your inquiries on the subject of rusty red heather, we have noticed several small patches of this all over the moor, and the majority of them are to be seen on the south-west and south faces of the hill, and a fair amount was to be seen on the low ground at ... This burned appearance first showed itself during the hot weather in the month of July, and that is the time that it is noticed each year according to keepers and shepherds. It is, of course, useless for Grouse-feeding purposes." Now this peculiar and serious condition of heather was, up to a com- paratively recent period, universally attributed to the action of frost, whence the popular name of "frosted heather," and even at the present time this opinion is firmly maintained in some quarters. After a careful investigation of the subject the Committee are now in a position to assert with some degree of confidence that the damage is the work of an insect. My own attention was first drawn to the question in the month of August 1897, when I received from a correspondent in Ayrshire a patch of heather, the shoots of which were brown and withered, while among the roots were a number of small grubs and pupse. My correspondent thought that the damage was caused by these insects, and at the same time he suggested that the diseased condition of heather which THE HEATHER BEETLE 417 was so widely known as " frosted " was identical with that of his specimens, and due to the attack of the same species of insect. Acting upon this suggestion, I examined the soil about the roots of this sample, and also of two others sent by the same gentleman a few days afterwards, and found therein numerous examples of the insect in all stages between that of fully- grown larva and mature insect. I succeeded in identifying the creature as a phytophagous beetle known as Lochmcea suturalis, Thomson, and immediately published a short account of it, with figures, in the "Annals of Scottish Natural History" for January 1898 (pp. 27-29). I thought little more of the matter until it was again brought to my notice in connection with the investigations of the present Committee. In order to obtain more evidence, either for or against the theory that the beetle was alone responsible for the damage, a circular was issued in January 1909 asking for reports from correspondents regarding the extent to which their moors had suffered from diseased heather, and requesting samples to be sent to me for examination. Before and after the issue of this circular I received typical examples of "frosted" heather from many sources, and it is important to note that ir( every case where the shoots had changed colour the leaves were undoubtedly nibbled by some insect, this being easily shown by examination with a hand lens. Not only were the bases and edges of the leaves eaten, but in many cases all the leaf had disappeared except the mid-rib, which remained as a kind of bristle on the shoot. The specimens now in the possession of the Committee furnish absolute proof that in all cases of diseased heather submitted to them the rusty red withered appearance is associated with, if not entirely due to, the attack of some insect, presumably the beetle referred to above, and which we now call the heather beetle. In order to ascertain if the beetle was actually present in the samples of heather sent not by any means an easy matter 1 devised a plan by which the little creature could be made to show itself. As all the samples were sent to me between the months of October and February it appeared to me probable that the insects, if present at all, would be in the mature stage, judging from what I had seen in the specimens examined in 1897. In all likelihood, too, they would be in a hibernating condition somewhere about the roots or surface of the soil. As it was impossible to find them without tearing to fine pieces every cubic inch of soil a most laborious task I hit upon the plan of soaking each block of soil, with heather attached, for several hours in water, gradually VOL. I. 2 D 418 THE GROUSE IN HEALTH AND IN DISEASE increasing the depth of the water until the actual shoots of the heather were submerged. It was very interesting, one might even say exciting, to see the result. In every case a beetle appeared a few minutes after the sod had been placed in water, to be followed every few seconds by another, and so on till they had all been driven out. In this way I examined sixteen samples of diseased heather, and only two of them failed to yield specimens of the beetle ; these failures must, I think, be attributed to the small size of the samples, for they were almost the smallest which I had received, measuring only 12 and 30 square inches respectively. The following table indicate the numbers of beetles obtained from the samples by the above method. No. of Sample. Date. County. Size in sq. inches No. of Beetles obtained. Remarks. 1 Oct. 13/1908 Lanark 288 47 2 Oct. 22, 1908 Argyll 288 70 3 Jan. 26, 1909 Selkirk 144 18 4 Jan. 30, 1909 Argyll 144 23 5 Feb. 4, 1909 Ayr 60 52 6 Feb. 5, 1909 Argyll 90 48 7 Feb. 5, 1909 Ayr 64 36 8 Feb. 6, 1909 Argyll 152 3 9 Feb. 6, 1909 Cumberland 2 Very little soil sent. 10 Feb. 14, 1909 Argyll 112* 21 Badly diseased. 11 Feb. 14, 1909 Argyll 72 7 A few twigs diseased. 12 Feb. 14, 1909 Argyll 148 11 Very little diseased. 13 Feb. 15, 1909 Argyll 35 6 14 Feb. 22, 1909 Argyll iH Very small sample. 15 Feb. 22, 1909 Argyll 30 Very small sample. 16 Feb. 22, 1909 Argyll 72 52 Badly diseased. If these figures are worked out they show an average of 1,437,480, or nearly a million and a half beetles per acre. Thus Lochmcea suturalis, if the cause of the diseased condition, is an important pest, and cannot be ignored. It may be of interest to give further extracts from correspondence, to show that the greater part of the evidence either actually supports, or at least is not in conflict with the idea that the heather beetle and not frost is the responsible agent in the devastation of so many acres of heather. (aa) " The enclosed . . . larvae I found yesterday on the ground amongst the grass and moss, where the heather is all dead and diseased. I thought THE HEATHER BEETLE 419 it might be the larva of the heather beetle, so thought I would forward them to you for examination." [Contents of box were nine larvse and twelve pupae of Lochmcea.~\ (bb) " Here we had very little signs of the insect last year, but this year it is over-running the moor and doing grea't damage. The insect made its appearance in beetle form in May. and its grubs about three weeks or a month ago, and is now to be found in hundreds on every bit of ' rusty ' and ' so-called frosted ' heather. The grub appears to appreciate [? prefer] young to old heather." (cc) " From what I saw . . . about six weeks ago, I have no doubt you are correct as to ' frosted ' heather. There are great areas and many patches of this brown, withered heather on the moor, and there was a whole colony of the larvse at the roots of every such patch we looked at." (dd) " My keeper has had two days on the moor, searching for the larvse or pupee of the heather beetle, and he can find none. ... I am sorry the search was not successful ; but the information that the larvse disappears between September 5th and November 5th amounts to something." (ee) " On the . . . moors there were, in places, many patches of the so-called frosted heather heather which had grown well up to a certain point, perhaps four to six years, and then without apparent rhyme or reason lost its sap and turned brown and withered before the flowering season. It looked very much like what heather might be expected to appear after a severe and late frost in May, but it was quite evident that atmospheric conditions (wind or temperature) had nothing to do with the result, as the ' frosted ' patch ended quite suddenly and was abruptly framed in perfectly sound healthy heather, which must have been exposed to exactly the same external conditions as the ' frosted ' heather. The keeper and I had many discussions over the cause of the spoilt heather, and we only agreed on one point, namely, that frost had nothing to do with the disease. I suggested a vegetable parasite, and he had views on improper burn- ing, and there we left the matter (both of us being wide of the mark as it turned out). On . . . .at the time I am speaking of, there was a very considerable quantity of the ' frosted ' heather ; I couldn't, even very roughly, give the acreage, but over the whole ground it must have mounted up to a big total, probably not much less than 750-1,000 acres. The 'frosted' heather is entirely useless for food, neither cattle nor sheep nor game will touch it so far as I know ; therefore in this particular year the wretched and insignificant little beetle destroyed the agricultural and sporting value of (?) 1,000 acres on one moderate- 420 THE GROUSE IN HEALTH AND IN DISEASE sized estate alone. How far the pest is spread over the whole of Scotland I don't know, but the total acreage of spoilt heather must be something very big indeed, and both the farmer and the game preserver have a very troublesome enemy to cope with in Lochmcea suturalis." (ff) " It may interest you to know what we have been doing about the heather beetle practically, they have damaged the whole moor, and we notice what I think was mentioned in your pamphlet, that they steadily work eastwards. We have been burning the affected heather as much as possible. At the time we were burning there was a very hard frost, and as regards the ground we turned up to examine we found the beetles not deep down as we expected, but clustered just round the root of the heather practically on the surface, and they didn't seem to be at all affected by the frost. I think it is a very serious thing for the moors in these parts, and hope that some effectual remedy may be found for them." (gg) " I am sorry to say the heather beetle is very bad with us this year. It was seen on the wing first on April 5th in very large quantities. Now [August] the grub can be seen in the roots of the heather. The heather which was badly affected last year seems to be quite dead, and has turned white. We found in burning this spring that where the heather was burned in narrow strips the portions of heather left between were specially badly attacked, which looked as if the fire had not killed the grub, but had driven them to the heather close by. In cases where we burned one side of a knoll, we find the side left has not suffered. This may be simply a coincidence, but would appear to prove that the grub can move short distances to find fresh heather to attack, but cannot move more than a few yards. With regard to stock of Grouse, we have never had such a poor show, although some of the moors in this district have a fair average stock. I think we shall have to face burning a very large amount of the dead heather next spring." (hh) "All the gamekeepers in this district obstinately maintain that the mischief is due to frost, but none of them can account for the fact of its only appearing in patches, and not by any means in the most exposed places." (ii) " In the diseased heather I cannot myself locate either beetle or grub, although I've seen both many a time." (Jj) "I send you a portion of damaged heather with peat. . . . My keepers here scout at the idea of beetles, and say the damage came too quickly and over too great a radius, and they consider it caused by sudden thaw on frosted heather and bleak east winds following." THE HEATHER BEETLE 421 (kk) " There was a good deal of frosted heather all over this country, and I have referred to it in my Report sent in to Mr A. S. Leslie. In my opinion the heather beetle was not responsible for the damage, at least on my own estate. The burned patches of heather were plainly noticeable within two days of the severe frost which occurred on April 23rd, 24th, and 25th last. The heather was uninjured on dry slopes, most of the damage occurring in wet, cold and waterlogged ground, and the patches have not extended since they were first seen. On a neighbouring estate I understand that the patches have been gradually extending ; but I have not verified this. I could understand the frost affecting places where the heather had already been damaged by the beetle ; but one would expect the injured portions to increase afterwards, and the heather to be affected on dry as well as on wet ground." (II) Same correspondent as (kk). "It is very difficult for me to believe that the injury to the heather is due to the beetle, though I can well believe the beetle is a contributory cause. It is easy to find any number of beetles about the roots of the injured heather. The injured heather was all apparent immedi- ately after the frost, and has not increased during the summer. It is also in places facing the morning sun as far as we can judge. ... In looking at the heather all over the hill there seems no place where it is quite perfect, that is to say, there always seem a few injured or dead shoots when one looks closely at it." (mm) " You will be interested to hear there is very little to be seen of the heather beetle this year, and this bears out our local experience of the pest, that after a wet winter the numbers and damage by them is very consider- ably checked, and that after dry winters they get bad again. This year we have had a very wet January and February, while these months in 1908 and 1909 were comparatively dry." (nn) "In the Field for January 31st, 1903 (p. 150), Mr William Prior, gamekeeper to Lord H. Bentinck, Deeside, Dent (Yorkshire), writes as follows : ' It is a fallacy to suppose that frost injures the tender shoots of the young heather in the young Grouse season, or that the frosts of April, May, or June are injurious to the shoots.'" (00) " I don't think very much heather has been destroyed by grub, certainly some has, but a good deal of heather has been apparently injured by the severe frost we had some days ago." (pp) " There were any amount of what I take to be the heather beetle 422 THE GROUSE IN HEALTH AND IN DISEASE under the frosted plants ; and if they are, there is no doubt of the cause of the blight. I am afraid it is only a severe winter which will do us any good." (qq) "Regarding the ravages of the heather beetle, there is no appear- ance of it in this district at present. Several years ago I saw a large patch of heather affected as described in your circular, but burned the whole of it at once. I knew it was the work of some insect, but I saw no more of it." (rr) " We are still finding heather destroyed by grub, but only in small patches. ... It is in the spring, I think, when the harm is done, and we arrange to have most of the diseased part burned as early as possible." (ss) " Am not aware of much damage to heather here, nor have I ever noticed any, except in the times when snow lay in sheltered parts for a fortnight or over ; after the snow had gone the heather came back to its former colour. In this locality I do not think the beetle does any damage." (tt) " I see we have several patches showing heather beetle ; we have a moss about 1,000 acres and only 15 feet above sea -level; this moss is at least one mile away from high tide mark, so the damage is not due to the effects of sea spray. I see no signs of it on the higher ground." On referring to the extracts here given (marked a to tt) the reader will gather that the damage is usually noticed between the months of April and August. As will be seen later, when the life history of the beetle is dealt with, these months are exactly those in which the beetle may be presumed to be in the egg and larval stages ; fully fed larvse are to be obtained in September, while the mature beetle hibernates during the winter, and has been noted on the wing in April and May (see extracts bb and gg). They would presumably pair and lay eggs in one or other of these two spring months, the egg state would only occupy a few days at most, and the larva would feed during the whole of the summer months. In most cases where the diseased heather has been examined in situ the beetles or their larvae (according to the time of year) have been noted as numerous, and these observations form an interesting supplement to the figures actually obtained by experiment. The districts from which damage from heather beetle is most commonly reported are those situated on the west coast of Scotland lying to the south of Oban. In Argyll, Ayr, Lanark, and Cumberland the pest is well known, whereas on the extensive moors in the northern and central Highlands of Scotland it is practically never heard of. It would appear therefore that the insect flourishes THE HEATHER BEETLE 423 best in a mild climate with a high average rainfall ; but it is curious to note that after a very wet winter the beetles are not so numerous as after a dry one. With regard to the position of the ground affected there does not appear to be any rule, for the extracts show the damage to be done on slopes which face all points of the compass from north-west' through west to south-east. Again, the age of the heather liable to attack appears to vary, for while two correspondents report that young heather is chiefly affected (h and bb), other two note the damage as done to the plants of from four to six years old and upwards (/and ee). Most of the damaged heather occurs in patches, although these may extend over a large area, and there is a certain amount of evidence that low-lying wet, mossy ground is most subject to attack. This may indeed well be the case, for the beetle requires a good deal of moisture during the period of its metamorphosis from larva to mature insect, and during the course of my breeding experiments any pupae which were allowed to become dry failed to develop properly. Taking, then, the whole of the evidence into consideration, I am strongly of opinion that the condition k^iown as " frosted " heather is entirely due to the attack of the heather beetle. Indeed, during the course of my experiments a patch of heather kept during the winter of 1908-1909 in a breeding cage in a warm room was eaten by a number of mature beetles kept in confinement. The condition of the shoots, after being nibbled, was undistinguishable in appear- ance from some of the samples sent in by correspondents for examination, and in this case frost was, of course, entirely out of the question. This experience is additionally interesting as proving that the mature beetle, as well as the grub, feeds upon the leaves. The question of remedy alone remains for consideration ; but this is a matter which presents some difficulty. It is obviously impossible to use any of the ordinary insecticides, as almost any chemical substance sufficiently poisonous to kill the grub or beetle would be very deleterious or even dangerous to the Grouse, to say nothing of sheep. The great extent of the area to be dealt with in most cases of attack is also a serious deterrent to the use of spraying mixtures. Extensive draining of damp, mossy flats might be indirectly beneficial as a preventative of beetles, and would be directly beneficial to the moor in other respects. But draining is an expensive business, and except in districts where the ground can carry a heavy stock of Grouse, or is valuable for pasture, it may be better policy to allow the low-lying flats to remain in a water-logged condition. Another remedy that suggests itself as, at any rate worth trying, is the 424 THE GROUSE IN HEALTH AND IN DISEASE introduction of some creature which would feed upon the beetle or its grub, and so keep its numbers well in check. Unfortunately the Red Grouse itself does not appear to devour the insect at all, but a close relative, namely, the Black Grouse (Tetrao tetrix) has been proved to have what may prove to be a fortunate partiality for Lochmcea suturalis. I have strong evidence, from two independent sources, of the truth of this. In December, 1908, Mr Eagle dlarke, Keeper of the Natural History Department, in the Royal Scottish Museum, received a small box filled with beetles, from Mr James Sword, of the Smith Institute, Stirling. In the accompanying letter it was stated that the beetles formed part of the contents of the crop of a Blackcock and had been sent to Mr Sword for identification. The rest of the contents consisted of the seeds of luzula and sheeps bitscabious, and nothing else so far as could be seen. The beetles, of which there were a great many, were handed to me, and I at once recognised them as our old friend, or rather enemy, Lochmcea suturalis. Again, in 1907, Professor E. B. Poulton, of Oxford, communicated to the Entomological Society of London an interesting account of the food of Blackgame, based upon observations made by Dr F. Menteith Ogilvie, of Oxford, to whom I here express my indebtedness for the reference. In this communica- tion Dr Ogilvie's notes on the contents of the crops of five Blackgame are reproduced, and in four cases out of five the heather beetle had been consumed in large quantities. These notes are of so much interest in the present connection that I cannot forbear quoting those portions which refer to the beetle. The summarised contents of the crops, numbered 1, 2, 4, and 5, include the following : (1) "An immense number of small dark brown beetles, Lochmcea (Adimonia) suturalis of Thomson." (2) "Many dark brown beetles, as in 5 of October 17th, 1907 [No. 1], but less numerous." (4) " Three hundred or more dark brown beetles (Lochmcea suturalis)." (5) " Immense number of the usual small dark brown beetle." " The two outstanding features are the spangle galls and the small beetle. Almost all the birds were crowded with these, and, judging by my specimens, the Blackgame must have been destroying enormous numbers of both. I don't think, as regards the beetles, it is any exaggeration to allow three hundred beetles per day per bird. Ours is not a very good Blackgame ground now, and perhaps we have three hundred head in all ; that would equal ninety thousand beetles THE HEATHER BEETLE 425 per day. I was surprised to find, too, how little heather was eaten in most cases, despite the fact that the birds were in almost every case found on the moor and not in the woods." It is interesting to note that this was written and printed before any one realised the importance of the heathe'r beetle as a destructive insect ! I have been informed that on certain moors it is difficult to induce Blackgame to settle and make a home ; but if they were once successfully established I cannot but think that they would become a useful means of preventing that wholesale destruction of heather which so often at present troubles the proprietors and keepers of our Grouse moors. Probably the only practicable method of dealing with the pest is that of burning the affected heather, not at the usual season for so doing, but at the time when the grub is on the shoots feeding. As the beetle hibernates between the months of September or October, and April or May, it appears to me to be of little use burning within this period, for the beetles would then be lying in a torpid condition below the surface of the soil, with cool and moist surroundings, and the flames would pass over them without doing them serious harm. The burning should, therefore, be done between May and August, when the grubs are up feeding on the shoots. There are two principal objections to this plan, namely, the legal aspect of the matter and the practical difficulty of getting the heather to burn when in a green and sappy condition. As the present state of the law prohibits burning in Scotland between April llth and November 1st special dispensation might be obtained in order to try the effect of burning the diseased areas during the summer months. The difficulty regard- ing the green condition of the heather might be got over by spraying the portion to be burned with some inflammable fluid such as paraffin or petrol, in small areas at a time, and well before any light is applied. This would have to be done with great care. It would not be necessary for the heather itself to be so thoroughly burned as in the ordinary operation for the purpose of promoting young growth for feeding, and I believe that the fire obtained from the inflam- mable agent itself might be sufficient to kill the grubs, even if the shoots did not burn so freely as at other seasons. 426 THE GROUSE IN HEALTH AND IN DISEASE Part II. The Life History of the Heather Beetle (Lochmeea suturalis). The heather beetle (Lochmeea suturalis), whose ravages form the subject of Part I., is a small creature a little less than a quarter of an inch (5% mm.) in length, of an oval shape, and usually of an olive - brown colour. It belongs to the family Chrysomelidse, and was first described as a distinct species in the year 1866, by the Swedish entomologist, C. G. Thomson, in his great work on the beetles of Scandinavia. 1 It is very closely allied to Lochmeea caprece, Linnaeus, a species which, as its name implies, feeds on sallow (Salix capred). From this it differs in having the forehead more shining, the little black tubercles immediately behind the bases of the feelers more distinct and polished, while the whole of the thorax is more shining. Since both species have been thoroughly described in the various works, British and Continental, which deal with Coleoptera, it is quite unnecessary to do more than refer the reader to the figure given on PI. LVIII. It is interesting to note that Thomson, in his original description, says the beetle is " not rare on Salix repens and other species of willow," while Julius Weise, in his account of the Chrysomelidse in the " Naturgeschichte der Insecten Deutschlands," says it occurs "on marsh plants, also on birches and willows in marshes." Canon Fowler, on the other hand, in his " Coleoptera of the British Islands," states correctly that it is found " on heather, by no means uncommon, and very widely distributed " ; but also adds : " it also occurs on birches and willows." My knowledge of the life history of this beetle is yet, I regret to say, incomplete. I have never seen or received larvae earlier in the season than the end of August, and by this date they are practically full-grown. From this stage, however, I have succeeded in rearing several specimens of the mature beetle, and have carefully noted the changes which take place, and the length of time taken to effect them. The full - grown larva is represented in Figs. 2 and 3 of PL LVIII. It measures, when straightened out, about a quarter of an inch (6 mm.) in length, but it is usually more or less curved, and if disturbed rolls itself up close. It is of a dirty white colour, studded all over with dark markings and tubercles, which have a definite arrangement on each segment. The segments- themselves are transversely wrinkled, while each tubercle is tipped with a fine 1 " Skandinaviens Coleoptera," vol. viii. p. 151. PLATE LVIII. V E. Wilson, Cambridge. Opposite p. 420.] THE HEATHER BEETLE 427 bristle of a pale brown colour. The dark markings are arranged as follows : Almost the whole upper surface of the segment immediately behind the head (that bearing the first pair of legs) is covered by a dark patch, which extends down each side to a level with the spiracles or breathing openings, and is divided down the middle by a fine line of the pale ground colour. Between this patch and the legs on either side is a small oblong dark patch two or three times as long as broad. On each of the two succeeding segments are two linear trans- verse dark marks, one anterior and the other posterior, and each divided in the middle like the patch on the first thoracic segment. On each side, opposite the extremities of each of these linear dorsal markings, is a more or less circular, but small, patch, the anterior one in each segment being smaller than the posterior ; below these, on each side, is a large dark patch of a kidney shape with the concave side uppermost, and below this again two small marks on each segment. On the dorsal surface of each of the succeeding segments are two transverse linear markings, one longer at the anterior edge and the other shorter and placed at the posterior edge. Between these and the spiracles are three dark spots on each segment, one of which is anterior and in line with the longer of the linear markings, and the other two posterior and opposite the shorter. Below the spiracles a series of large more or less circular spots runs along the side of the body. The head is black and shining, and hemispherical in profile ; the legs black, with the basal joints marked with white. When the larva is about to pupate it crawls down to the ground and lies amongst the moss and stems of the heather, at the same time curling itself up into a sort of horse-shoe shape. The anterior half of the body becomes gradually stouter, and the larva adopts the peculiar and interesting habit of suddenly straightening itself and then reassuming the horse-shoe form. In course of time, by this means, the skin of the dorsal surface of the three segments behind the head splits, and the emergence of the pupa is gradually effected by wriggling. This process, as I have observed it, in favourable circumstances may be accom- plished in twenty minutes, but may also take an hour or even more. The pupa, when newly emerged, is of a creamy white colour throughout, with the exception of the tiny bristles about to be mentioned, which are blackish. The characteristic form of a Chrysomelid beetle is now distinctly traceable, while the legs, wing-cases, antennae, and even mouth-parts can be recognised. Seen from above, the hemispherical thorax (prothorax of the mature beetle) occupies the most anterior portion of the body, and carries about a dozen tiny bristles, 428 THE GROUSE IN HEALTH AND IN DISEASE four of which form a curved row near the posterior margin, and the rest a row near the anterior margin. In a dorsal view the head is quite invisible. The meso- and meta-thoracic segments, and those of the abdomen, are each provided with a row of four bristles, which are about equidistant from each other. Laterally, below the level of the spiracles, the abdominal segments are each tipped with a tiny bristle. Seen from beneath (see PI. LVIIL, Fig. 4) the pupa shows distinctly the legs folded up close under the body, and the antennae beautifully curled under the two anterior pairs of legs and brought out again so as to show the tip of each close to the four anterior tarsi. Most of the joints of the legs may be distinctly seen, the posterior pair being folded beneath the wing-cases, which are bent round from the dorsal surface of the pupa and do not nearly reach the end of its body. The first change to be noticed in the pupa is that on the fifth day after emergence the eyes begin to change colour, assuming a pale brown tint, while a couple of days later they are of a more distinct brown, and the separate facets 'may be distinguished. On this day also (the seventh) the extreme tips of the mandibles become darkened. Six days later the eyes have become very dark brown, almost black, while the mandibles are of a rich brown tint. When two more days have elapsed, i.e., on the fifteenth day of pupal life, the tips of the mandibles are quite black, while the maxillae have commenced to darken at the tip. On the seventeenth day the wing-cases, legs, and antennae darken in colour, and the markings on the forehead, etc., characteristic of the mature beetle, are plainly seen, while on the eighteenth day the changes are fully accomplished, and the beetle emerges to enjoy a free and active existence. The pupal stage thus lasts, in a typical case, about three weeks. The emergence of the beetle from the pupal skin commences with the liberation of the legs from the body, and occupies, judging from an example which I carefully watched, about four hours ; but the elytra (wing-cases) are even at the end of that time quite pale, and only darken and harden quite gradually, assuming their permanent condition several hours later. The anterior legs and the antennae are the first appendages to become capable of free movement, while the whole of the six legs are practically free in the space of an hour. As the struggling movements proceed, it is easy to notice the extreme thinness of the enclosing pupal membrane. It is apparently of considerable toughness, but is ultimately ruptured by the vigorous, movements of the limbs. THE HEATHER BEETLE 429 After observing the above details in the transformation of several examples, I placed all the newly emerged beetles, together with a large number of others received from correspondents, in a breeding-cage on a sod of healthy heather. In a very short time they had all disappeared, and in order to satisfy myself as to their whereabouts I detached a small piece of the sod (about 4 inches square), and tore it carefully bit by bit into small fragments. In this way I found in this small piece five beetles lying in a torpid condition in little hollows immediately below the surface of the soil. When the moss, etc., was gently torn off, the beetles were betrayed by their shining elytra, as they lay back upwards. They began to move when disturbed, and three of them got away and were recaptured. This observation tends to prove that the beetles assume the hibernating condition immediately after completing their development, which in most cases is effected by the third or fourth week of October. This date, of course, may vary slightly according to local conditions. It is a matter for regret that I have not been able to trace the life history any further. Considerably over two hundred specimens were kept alive in my cages throughout the winter, and early in the spring of 1909 (March 2nd and succeeding days), under the influence of the sunshine streaming into the room, they emerged from the soil in numbers, and became very active and excited, a few specimens indulging in short flights. Several were soon pair- ing ; but I was never able, even with the most careful searching, to discover any eggs. Further investigation is therefore necessary before the biography of this interesting little beetle can be fully written. CHAPTER XX KEEPERS AND KEEPERING, WITH SUB-DIVISIONS DEALING WITH POACHERS AND VERMIN By Lord Lovat IT is a very common belief amongst moor - owners tacitly accepted rather than openly confessed that provided the proprietor is interested in moor management, his keenness in the shooting season, and his intermittent interference at other times of year, will make up for any shortcomings on the part of his paid keeper. This is, unfortunately, very far from being the case. Great help may undoubtedly be given by advice and criticism, and the interest of the superior cannot fail to stimulate the keenness of the sub- ordinate. Still the fact remains that however accurate may be the The im- portance of theoretical knowledge of management of the landlord, and however the keeper. complete his personal attention to the general principles of moor hygiene, the gamekeeper will always remain the executive officer responsible for the thousand-and-one details on which the health of the moor ultimately depends. In undertaking the management of shooting, it is, therefore, of primary importance not only that a good keeper should be chosen, but also that the terms of his engagement, the nature of his duties, and the extent of the assistance, both permanent and casual, to be given to him should be of such a kind as to give him the widest scope for efficient service. It is not intended in this chapter to go at length into a description of the methods of selection of a keeper, or the technical details of the duties that he should carry out after appointment. The Committee only desire to suggest a few general principles founded on observations made during the course of the Inquiry, and shown by experience to be established on a strong and certain base. In the first place it may be stated as a universal rule, and from this 430 KEEPERS AND KEEPERING 431 there should be no departure, that the keeper should be the owner's and not the tenant's servant. The reasons for this are many, and it Keepers would be hardly necessary to go into any of them were it not that the"owner's this somewhat obvious precept is as often honoured in the breach servants - as in the observance. A tenant, from the very definition of the term, is an individual possessing but a temporary interest in the moor he rents. The tenant's keeper also, whose arrival and departure synchronise with the period of his master's lease, naturally looks to his immediate superior's interest rather than to the future welfare of the estate, or of those permanently connected with it. In cases of Grouse moors where the heather is well burned, where there are no troubles connected with rabbits, sheep stock, or rights - of - way , and where, broadly speaking, the interests of both contracting parties are identical, difficulties may not occur ; but this satisfactory state of affairs does not always exist. On a badly burned moor, with large tracts of rank, overgrown heather, it is difficult to see how the immediate interests of a progressive landlord and those of a shooting tenant on a short lease can ever be made to coincide. Conflict of If the landlord knows his own interests, his first object must be to interests burn big stretches of stick-heather in order to get the moor into a landlord mi i i TIII an d tenant. proper rotation of burning, ihe tenant, on the other 'hand, should he be equally well informed, knows that though such heavy burning may be beneficial to the moor in future years, the resulting crop of edible heather will not be increased during his occupancy. The keeper, therefore, who burns in the tenant's interest will burn in the smallest patches, not in order to increase the food yield so much as to provide basking ground for the old birds, and drying ground for the young chicks. He will leave severely alone the big blocks of old or dying heather, for on these he depends for cover for the stock of birds which happen to be on the ground, their prospective food value not being his concern. This method of heather management, though suicidal, is by no means uncommon, and instances could be given in Scotland and England of magnificent moors on which no long heather is being burned, and which at the end of the current leases will show a decrease of 50 per cent, in value, and that for many years. Another reason why the tenant should not directly employ the keeper is 432 THE GROUSE IN HEALTH AND IN DISEASE that the former is, as a rule, but an autumn visitor. Though his trust in gh ,. himself be great, and his experience of shooting not small, his tenants knowledge is but too often confined to the months when the heather autumn i s i n bloom, and the climatic conditions are at their best. He may visitors. never have visited the ground during the late winter and early- spring months, when the food is short and when the results of moor manage- ment are put to the test. The tenant's knowledge of keepers and their duties is also apt to be perfunctory. A little keenness at shooting time, and a few excuses on the plea of a wet nesting season or bad weather for heather - burning, are quite enough to satisfy the average tenant that every effort has been made to get the best possible results from the moor. In this way the inefficients escape dismissal, and the specious are awarded undeserved praise. When the keeper is the landlord's servant a very different state of things exists. In the first place, the supervision is continuous and not inter- mittent. In a year with a short burning season, the foresters' staff, tages'of t ne shepherds and the labourers employed on the estate can be turned on for a few days' burning ; draining can be done under an servant expert sheep-drainer, and the estate personnel and organisation utilised without incurring additional expense. Again, in dealing with grazing tenants, the landlord's keeper gets more effective support from the agent, and has the minor difficulties arising from sheep gatherings, dippings, etc., more satisfactorily settled than if the arrangement has to be made through a third party or by a stranger. This question of the relations between the gamekeeper on the one hand, and the agricultural tenants and their employes on the other, is one to which it is impossible to attach too much importance. The efforts of the most efficient gamekeeper may be nullified by the spite of a hostile farmer or shepherd, while, should a good understanding exist, it will be found that the interests of the moor are studied by all, and that every shepherd is a self-appointed watcher, and not infrequently the best informed man about the moor. Without dwelling further on this aspect of the question, it may be said that whether from the point of view of management, supervision, or outside help, grave risk is incurred, and no advantage gained, by the transfer of the keeper from the landlord's to the tenant's service. KEEPERS AND KEEPERING 433 As to the exact terms of service, no general rules can be laid down. Wages differ in different parts of the country according to local customs, cost of living, etc. It may, however, be stated that it is a good Terms of policy to pay keepers a fair living wage, not only with a view to service - securing good men, but also to list them realise that their services are appreciated, and that they have a billet which it is worth their while to keep. Zeal may be further encouraged by periodically increasing the wages of a keeper who by his personal efforts has improved the value of the shooting under his charge. When this policy is adopted the criterion should be the net improvement over a term of years, and not the chance bag of one lucky season. Though the rate of wages may vary with local custom and payment individual largesse, there can be no doubt on one point, viz., that n "t k recLn- the emolument should be in "coin of the realm" and not in "kind." mended - The keeper should be a keeper "first and last and all the time." In England a garden or the grazing of a couple of cows may be a desirable addition to wages ; in the Highlands a small croft may be a necessity ; but in either case agricultural enterprise should be kept down to the margin of personal comfort, and not regarded as a substitute for wages, nor should it be allowed to afford a separate means of livelihood. The keeper's place is on his beat, and not at the market - place watching the sale of stock. Above all things a keeper should have no interest in the sheep grazing on his beat. A man cannot serve two masters, nor should a keeper practise his retriever in herding a ewe stock, or keep his nesting ground quiet by pushing up the lately returned winter "hogs" to the high ground. Many employers prefer their keepers to be married men, and there is much to be said for the preference. A married man is less dependent upon his neighbours for society than a bachelor, and so can go about his business without attracting attention ; for the same reason it is often better for a gamekeeper's house to be situated some distance away from other habitations. In addition to the adequate payment of keepers, the establishment of a pension fund is a question well worthy of consideration. There p ens i on is a Scotch maxim, " A stout heart to a stae brae," and a servant ] who has to get his beat burned in the short time available in autumn VOL. I. 2 E 434 THE GROUSE IN HEALTH AND IN DISEASE and spring, hunt up his assistants and keep them employed, watch his moor when poaching is probable, be at his master's command early and late, and at the same time look after his traps, must be a man in the full vigour of life. Hardy as the race of keepers is, the time must come when retirement falls to the lot of even the most resolute. There is no objection to the head-keeper being a man of mature judgment and of riper years. The very fact that he has reached a time of life when he realises that he is unable to do all the work himself, will make him delegate his command, and by increased attention to his subordinates see that the work of all is efficiently carried out. For the under-keeper who has neither the grit nor the brains to climb to the top of his profession a change to some low - ground beat or to the gate - keeper's lodge will often quickly repay the cost of transfer. There is some difference of opinion as to the number of under-keepers required for a given area of Grouse ground. Speaking generally, the Committee hold that many English moors, and most Scottish moors, are under -keepered. keepers This finding may not be readily accepted by the parsimonious, but a necessary. . . little study of the financial aspect may bring conviction. Ihere are many moors of 6,000 to 10,000 acres in extent with one keeper in sole charge. An area of this size can hardly be looked over every week, far less trapped, burned, and watched by a single man. On many such moors even one section of 1,000 acres, properly administered, may easily yield a permanent increase of one hundred brace, which, if translated into money value, would represent considerably more than the yearly wage of an under-keeper. The loss arising from bad or insufficient keepering is often not fully appreciated. A very small number of stoats or hooded crows do an amount of damage which would exceed the annual cost of an extra Dangers of . insufficient hand. If we realise that cases can be quoted where a single pair of " hoodies " have been responsible for the destruction of a hundred eggs, or where individual foxes and peregrines have killed a score of paired birds (equivalent to the loss of fifty brace in the shooting season), it is no exaggeration to say that on good Grouse ground adequate super- vision must be obtained at any cost. It is difficult to lay down exactly the extent of ground for which an under-keeper can be responsible. This varies with the shape of the beat, the character of the ground, the stock of birds, the quantity of vermin, the amount of night watching required, and KEEPEES AND KEEPERING 435 the outside duties under the keeper's charge such as rabbit - trapping, low- ground watching, fishing, etc. It may, however, be said that on a hill moor with no low ground one keeper should be able to trap, and with proper assistance to burn, from 2,000 to 4,000 acres. As to the selection of keepers some owners have a preference for dalesmen, some prefer south country Scots ; some, very rightly, have a prejudice against men who have come from a rich man's employ ; others will only take s e i ect i on men off a moor on which a big staff of keepers is kept. It is ofkee P ers - difficult to generalise. Good men, like good horses, run in all shapes and from all countries, but it will probably be found advisable, where possible, to take a man who has been "through the mill," who has acted as a kennel -boy under a head-keeper, who is himself a good trapper and an honest man. Whatever fancies may influence the selection of the keeper the essential qualifications can readily be defined. A keeper must be a good trapper, an observer of natural conditions, and a man with the interests of the moor at heart ; above all things, he must be a worker, not a gentleman who goes to the hill with a gun. It is hardly necessary to point out, that when the good man has been secured, he must be kept up to his work by periodical inspection. A check should be kept on the amount of heather burned, the vermin list should be frequently looked over, the number of traps actually at work should be ascertained from time to time, if necessary by surprise visits. To those acquainted with the best type of gamekeeper, it is not difficult to separate the sheep from the goats. The series of disasters which has made all heather burning impossible, the combination of chances which has prevented the traps being set on the day of the inspection, the number of vermin skins that appeared on examination to have weathered more than one winter's storms, the chance which has made the area visited the only badly burned portion of the moor, all afford reasons to show why Napoleon in his wisdom elected to employ excuse-free generals born under a fortunate star. To sum up, a sufficient number of keen young keepers, adequately paid, able to trap, willing to burn, properly supervised by a head-keeper who knows every detail of moor management, should give the required result. On small moors where only one keeper is employed that keeper must combine the qualities of head-keeper and under-keeper ; he must have the knowledge and sense of responsibility of the former with the capacity for 436 THE GROUSE IN HEALTH AND IN DISEASE hard work so important in both. Many men of this stamp are to be found, and even if at first a young keeper may be lacking in experience he will soon acquire the necessary knowledge if he is willing to learn, and if his employer is competent to instruct. Every effort should be made to foster the sense of responsibility in a game- keeper. The importance of this will be admitted when it is considered that during many months of the year the keeper on a Grouse moor is out of touch with his employer, and, if he chose to do so, might leave his beat to look after itself and to become a happy hunting ground for vermin and poachers. Detection of shortcomings is extremely difficult, for no master cares to spy upon his servants, and the sporting department of an estate is seldom if ever efficiently controlled from the Estate Office. Keenness is undoubtedly the basis of the sense of responsibility. If a keeper's whole mind is concentrated upon how best to improve his beat very little training is required to turn him into a conscientious and responsible servant. A young keeper should be given, and encouraged to read, the best books on moor management ; he should be made to give frequent reports upon details affecting his beat, both for the employer's information and to help him to realise the many points which require atten- tion. A keeper quickly realises that his opinions are listened to, and is thereby stimulated to experiment in new methods, and attempt to prove their value by definite results. It is a matter of surprise to those acquainted with sport, many of whom lead an over-busy life in our cities for the greater part of the year, what a number The ideal ^ capable men, intelligent, articulate, shrewd observers, not only of keeper. natural history but also of men and matters, are included in the keepers' ranks. There are few owners of moors who have not had the good fortune at one time or another to have men of this stamp in their employment ; men who are friends rather than subordinates, with a frank contempt for, or rather a complete ignorance of, the ordinary conventions which sonai restrict the intercourse between class and class. Men of few words in qualities. company but with that power of expansion when the audience is congenial, men who are eager to learn and to accept both new views and new facts on every point connected with their profession. It is a real pleasure for any one interested in animal life to take the hill in company with a man of this sort. The habits of the dwellers of the moor, the history of the locality, old-world traditions, the beauty of the surroundings, the customs, KEEPEES AND KEEPERING 437 habits and idiosyncrasies of the visitors, are commented upon with shrewd observa- tion not unmixed with humour, the whole presented from the detached point of view of the man who is a lover of his profession, who is outside the scramble for preferment, who is satisfied with his position, and does not mean to leave it. To the really efficient head -keeper the "big shoot" comes only as the crowning circumstance of a busy year. All details have been so carefully prepared beforehand that on the day itself every part of the complicated His power p 11 j *_ i J_T_ j.- i of organisa- organisation falls into its proper place at the proper time. To the master of the art the wind is always in the " airt " from which the birds can be most easily manoeuvred. Flankers appear by magic in the gully down which, for the first time in the memory of man, the birds have begun to break away. There is an order and bustle about events which acts like magic on the most dilettante breakfast-eater, which pushes on the most grasping of the guns from the " pick up " to the next row of butts, and which even stimulates the gentleman's gentleman to take that extra bag of ammunition which is to help to create the record day. While the work is proceeding there is no bellowing of forgotten instruc- tions, no downwind drives in which startled coveys and volleys of objurgations hurtle past alternately on a full autumn gale. Drive succeeds drive in orderly sequence. The flickering of a parti-coloured flag, quickly seen and answered by the flankers, is all that betokens the master mind. The birds rise, swing round to the downwind flankers, a sudden display of colour, and in a moment they are over the centre of the line. Little escapes the observation of such a man ; even the expert in excuses modifies his usual explanations, the most hardened cartridge burier ceases for a while from his miry operations below his butt. It is not necessary to dwell on the companion picture. The head-keeper who on the day of the shoot prepares to visit the moor for the first time, the shouting and noise which is supposed to make up for the laziness contrasted of eleven long months, the beating of dogs, the coursing of hares, the ^'efficient loud echoes which perplex the under - men and frighten the game, kee P er - all proclaim inefficiency and generally promise bad, certainly unenjoyable, sport. So much depends on the keeper, not only with regard to the bag to be obtained, but also with regard to the satisfaction of successful manage- 1 While making due allowance for the high standard of intelligence required for the successful driving of Grouse it is remarkable how many gamekeepers are not naturally gifted with this particular form of genius. In nearly every case where a gamekeeper is a master of Grouse-driving his efficiency may be traced to the careful training he has received at the hands of an employer who has himself thoroughly studied the subject. 438 THE GROUSE IN HEALTH AND IN DISEASE ment the pleasure and interest of well-organised shooting, that no effort should be spared to secure the suitable man. The keeper's duties in regard to vermin, poaching, control of old heather, and stock regulation are dealt with in other parts of this Report. 1 Certain general rules of conduct are however worth noting. The first rule to be laid down is that a good gamekeeper should never Principal be idle. It is a fair criticism to make that laziness is the commonest game 80 fault in gamekeepers. Also that this laziness in the majority of cases arises from ignorance and not from malice prepense. Many zealous young gamekeepers have been brought up to believe that their whole duties are to burn the heather in the spring, to attend upon the guns in the shooting season, and during the remainder of the year there is to keep their eyes open, but on no account to disturb their ground, low This belief is convenient for the idle, and had its origin no doubt from small shootings, where one man has charge of both Grouse moor and low ground. The sequence of duties on such shootings went on without a break from heather-burning to Pheasant-rearing, and from Grouse shooting to covert shooting ; a sufficient round of activity to occupy the keeper's time throughout the year. The arrangement was probably considered satisfactory from the point of view of estate economy, even if it did not give a maximum yield of Grouse. Where a keeper has charge of Grouse ground and Grouse ground only, a higher standard should be aimed at. He must discard the old belief in an Where " off season," for the " off season " should be his busy time. He moor' 8 must overcome his dread of disturbing his ground even at the breed- ing season, for it is then that there is most to be learned as to the nesting capacity of his beat, and the means by which this nesting capacity might be improved. He will not find that the hen bird will desert During the 3 nesting merely because he happens to have located her nest, whereas if he season. remains at home one pair of hoodie crows may do as much harm as if he had spent a day walking over the moor and putting his foot on every clutch. 2 1 Vide pp. 445 et seq. ; chap, xviii. pp. 392 et seq. ; chap. xxi. pp. 454 et seq. - Many game preservers will challenge the foregoing remarks as contrary to all accepted theories ; hut against theory can he put actual experience. One example only need be given : On a moor which has come under the Committee's observation, where the annual hag has been known to reach the remarkable total of eighteen hundred brace off 2,000 acres of heather, the gamekeeper in charge by close and constant attention to his duties is able to inform his employer whether it is to be an early or late nesting year, whether the stock is large or small, whether the clutches are above or below the average, and how each beat KEEPERS AND KEEPERING 439 While it may be admitted that all needless disturbance is bad it must be remembered that Nature has provided certain safeguards for the protection of the stock at the most critical period of their lives. It is almost impossible to flush Grouse at this season, and one may walk- all day over a well-stocked moor without seeing any indication' of the presence of birds except by their droppings. Any Grouse that may be flushed are usually cocks or barren pairs, and the sitting hens remain undisturbed though the intruder may pass within a few yards of them. Certain precautions must of course be observed, the keeper must avoid all noise, and must not return again to the spot when he has marked a sitting bird. He must creep about the moor rather than walk openly, and above all he must not be accompanied by a dog. There is a growing feeling among moor - owners that closer supervision during the nesting season is desirable, and need not be followed by disastrous results. In another department of game preserving the nesting arrangements of wild birds are assisted by such plans as the so-called " Euston " or " Stetchworth " systems, whereby the period of incubation is shortened by removing the eggs from Partridges' nests and substituting for them other eggs that have been almost hatched under a barndoor hen. The results in many places have been most successful in spite of the disturbance caused by searching for the nests and transferring the eggs. 1 When the keeper has been trained in accordance with conventional doctrines his knowledge of the moor during the nesting season is often very incomplete. He conscientiously marks down some half dozen nests on the edge of the moor, and from these he judges the prospects of the whole ground. If the nests under his observation are flooded out by heavy rain, or destroyed by frost, he reports that the season will be a poor one, whereas if they hatch out successfully his hopes run high, for in his ignorance he does not take into account the distant beat which has been harried by vermin, or the waterless waste in the centre of the moor, where no wise Grouse will select its breeding ground. It must not be thought that the sole object of watching the stock during will turn out. This information is obtained by marking any nests that may be found by chance (nests are not deliberately looked for), and by carefully observing the droppings of the " clocking" hens and the young birds. As a rule this gamekeeper and his master form a fairly accurate idea of how the season will turn out even before the dogs are run in July ; after this final test it is possible to prophesy the bag with some confidence. 1 For a discussion of the " Stetchworth " and other methods of Partridge preserving see Teasdale-Buckell, " The Complete Shot," pp. 246-256. 440 THE GROUSE IN HEALTH AND IN DISEASE the nesting season is to form an estimate of the shooting prospects, though improve- as w ^l be shown later an early knowledge on this point is of primary importance in regulating the stock. The foregoing remarks are intended J i ground. merely to emphasise how closely a keeper may keep in touch with his duties without unduly disturbing his ground. In the performance of these duties many practical benefits result. The observant keeper will first of all note which areas are most favoured by nesting birds, and will try to discover what are the particular conditions which may be profitably introduced in the less favoured areas. Some of the favourable conditions may arise from the configuration of the country, a sunny exposure, good natural drainage, shelter from the coldest winds, etc.; but many may be reproduced by artificial means. Natural drainage may be to some extent replaced by carefully constructed artificial drains, the patent dew-pan may be substituted for the burn which has run dry, or a drain and conduits may be constructed to bring a copious supply of running water through the driest parts of the moor. Bad feeding may be improved by intelligent heather culture, gravel may be exposed, or heaps of broken quartz deposited, in the soft, peaty parts of the ground where there is a deficiency of grit ; and thus the nesting capacity of the moor may be extended. It may be argued that the Grouse will always prefer to nest in the places which possess good natural conditions, and this is no doubt true ; still a season will come when a specially heavy stock has been left, and the possession of a reserve of nesting ground may mean the salvation of a moor which otherwise would become overcrowded. On his visits of inspection during the nesting season the keeper's hands should never be empty, and his eyes should never be closed to the work to improve- ^e done, the drainer's spade will be found more useful than the gun, dra?nsand an( ^ * en mmu tes' work will convert a choked- up spring into a clear springs. drinking pool. The dangerous banks of steep-sided drains may be sloped away at suitable intervals, so as to make safe landing stages for any chicks that may be caught unawares by a thunder shower. The fan-shaped morass which spreads down hill from every spouting spring will be tapped at its source, and thus acres of green moss and rushes will be turned again to heather. This will not be the only advantage gained ; every stroke of the spade will turn up the grit so often described as " the life of the moor." There is no room for vermin and an active gamekeeper on the same beat. His constant presence drives away what he cannot destroy, or at least disturbs KEEPERS AND KEEPERING 441 the raiders in the prosecution of their designs. The methods of trapping or otherwise destroying vermin are dealt with in another part of this chapter, and here it is only necessary to say that whenever *i" of vermin. the keeper sees a fox or a stoat or a hooded crow upon his ground he should never rest until he has made an end of it. Every addled Grouse's egg should be given a chance of retrieving its failure by becoming the death- meal of some mountain robber. A keeper should be judged by the paucity of vermin to be found upon his beat, not by the total number he can kill each year. During the hatching season, and until the young birds begin to fly, the game- keeper may continue to watch his growing stock. About this time also he may employ himself upon the building up of Grouse butts and the bushing . . of wire fences with bunches of heather. In June and early July much butts: bush- iii To see the hooded crow with small beady eye hunt a hillside, drop' down beside a pair of Grouse whom he suspects of having a nest, to watch his casual walk round as if merely on a tour of inspection, the fierceness with which he darts at and drives away the pair from their eggs or young, returning again and again until the last of these has been taken, leaves no thought of pity even in the most tender-hearted. The hooded crow usually nests in the birch woods or plantations at the edge of a moor. It is fortunately easy to kill the pair in the nesting season, and they can be trapped with bait at all times of the year. In the nesting season there is no bait like an egg, and even if the "hoodie" does not fall a victim to this bait, it may prove the death of a stoat, a rook, or some other equally objectionable scourge. Rooks are nearly as destructive as hoodies or carrion crows on some moors, for the supply is inexhaustible, and the nests being at a distance Books. cannot as a rule be destroyed. Jackdaws are often a serious pest upon a moor, and should be kept in check with a firm hand. Their numbers can best be reduced by Jackdaws. harrying them in the breeding season. If the old birds are kept off their nests in frosty weather the eggs will become addled. An interesting example of the damage caused by jackdaws is furnished by a correspondent of the Committee who rents a moor in Scotland. Before he took the moor the average bag was about sixty brace, and the ground was overrun with vermin, more especially with jackdaws, which nested in the rabbit holes on the hillside. The tenant at once commenced to wage war upon the jackdaws, and offered a sum of one half-penny an egg to any boys who robbed the nests ; in each of the last three seasons he has taken over one thousand jackdaws' eggs one boy alone collecting upwards of five hundred ;. at the end of the third season the bag had increased to over two hundred brace of Grouse, while a large breeding stock was left. The jackdaws' eggs were found very useful for feeding young pheasants. Ravens are already so persecuted by the shepherds that they hardly count, though there are still a fair number to be found in the remote Ravens. fastnesses of the Scottish deer forests. The golden eagle is too noble a bird to rank in the list of vermin. He occasionally kills his Grouse on the wing, but feeds for choice on hares, (j id e n with an occasional deer - calf or lamb for a change of diet. In ea e le - former days, when eagles existed in large numbers in the Highlands, their VOL. I. 2 F 450 THE GROUSE IN HEALTH AND IN DISEASE depredations were so serious as materially to interfere with sheep farming. The eagle cannot be said to be a desirable recruit to the ranks of the flankers in a Grouse drive ; although he not seldom takes on himself this duty, to the rage of the keeper and bewilderment of the birds. Of the hawk tribe all are occasionally destructive ; but it must Hawk-S not for a moment be supposed that all should therefore be destroyed. The kestrel or wind-hover probably does more good by killing mice and rats than he does harm by the destruction of a few young Grouse. The buzzard confines himself almost entirely to small birds, carrion, and ground game. The greater blackback gull is destructive both to eggs and young birds, and should not be allowed to infest any moor on which it is intended Gulls. to preserve a stock of Grouse. The black-headed and common gulls are destructive to eggs in certain localities ; this, however, must be regarded as an exception rather than as the rule of their habit of life, for Grouse frequently nest and hatch out their broods in the centre of breeding colonies of these birds. POACHERS. It has always been customary to divide poachers into two classes, the TWO kinds professional poacher, who makes poaching a means of livelihood, and er- the occasional poacher, who only takes game for his own consumption, or to satisfy what is called his sporting instinct for the property of others. The professional poacher is a dangerous and undesirable member of the community, and should receive no mercy. He is generally devoid of all the finer feelings, and his sole object is to enrich himself by appropriating, fessionai in the largest possible quantities, goods that are not his. He usually belongs to the submerged class which is recruited from the ranks of those who have gone under on account of their own shortcomings dis- honesty, drink, or congenital laziness. In certain country towns and villages, especially those occupied by a mining or manufacturing population, poaching is not looked upon ing com- as a crime, but as a perfectly respectable and often remunerative munity. . means of occupying leisure time. When this feeling exists the task of game preserving is a serious matter, and the preventative measures employed measures - KEEPERS AND KEEPERING 451 resemble the levee en masse rather than what might be called the keeper's "level of every days' most quiet need." Fortunately for the owners of Grouse moors it is the exception to find the professional class of poacher a very serious menace, owing to the remote- ness of moors from the centres of-, population. Nevertheless, the r\ Grouse armed gangs do occasionally turn their attention to Grouse, as may poaching be proved by the supply of freshly killed birds that appear in the windows of the poulterers' shops on the morning of August 12th, earlier than could have been possible had they been killed in the ordinary course of sport. Systematic poaching of Grouse for the market is less common now than it was in former years. The increase in value of Grouse moors has led to more careful watching and to more severe prosecution, the pro- i, n p rove . prietors in the principal game - preserving counties have in many cases combined together to form associations for the protection of their sporting rights, and the duty of bringing the wrongdoers to justice has been entrusted to competent men. The habits of the Grouse, too, have changed in recent years ; whether owing to the introduction of driving or because of the destruction of birds of prey, Grouse are much wilder at the beginning of the season than was formerly the case, and on many moors will not sit to dogs at all. Twenty years ago it was not uncommon for the poacher's gang to spend the nights of August 10th and llth hunting the moors with a steady close- ranging pointer. Sometimes it is related that a lantern was sus- Q rouse pended from the neck of the dog in order that his movements j^formw might be followed in the dark. On obtaining a point the poachers days - would make a detour, and would gently draw a net down wind towards the dog and drop it over the covey. These nets were sometimes captured, and may still be seen hanging as trophies on the walls of some of the shooting lodges in the North : they are beautiful pieces of work, usually made of silk, very light and very strong. The only time when Grouse can still be poached with ease is towards the end of the season when they pack and flock to the low ground to feed on the corn stooks. On these occasions they may be snared by horsehair nooses, and there is no doubt that in certain districts this form of poaching on the stocks. is carried on. As the majority of " corn-feeders " are young birds^ this form of poaching is specially harmful to a moor. There is no excuse 452 THE GROUSE IN HEALTH AND IN DISEASE for the gamekeeper who permits it. The cornfields to which the Grouse resort, and the hours at which they feed, are perfectly well known, and it is the duty of the gamekeeper to be constantly on the spot. The subject of poaching cannot be considered complete without some reference to the pastime of " Grouse - becking " as practised in the north of England. Becking has already been mentioned in another part of the Report, 1 and the manner in which this habit of the bird has been utilised by poachers is graphically described by the Rev. H. A. Macpherson in the Fur and Feather Series. 2 Occasionally the professional poacher goes alone and boldly carries a gun. This method is common in the extreme north of Scotland, where the day- light is of such long duration that it is almost impossible for the gamekeepers to be always on the watch. It is a well-known fact that in flat, featureless country it is very difficult to detect a man upon the moor, or to hear the sound of a shot. All professional poaching might be prevented if the sale of game by unauthorised persons were discouraged. Game - dealing licences are granted Facilities ^ ar to often to small country tradesmen, who are prepared to act Twached 0f as ^ e receivers of stolen goods. This might be avoided by granting only a limited number of licences in every town, and only granting them to responsible persons. The licensed game-dealer is supposed to ascertain that the vendor had come by his game honestly, but the law in this respect is seldom enforced. The occasional poacher is a nuisance, and requires careful watching, but it is doubtful if his depredations ever materially affect the stock upon a moor one pair of hoodies, or the mildest attack of disease, will do .L iii' occasional more to damage the season s prospects than a score of crofters who poacher. take an odd Grouse to give a flavour to the broth. Though the occasional poacher may not do much harm he must not be encouraged, he disturbs the ground, and wounds more than he kills ; too often he is tempted by success to join the ranks of his professional brethren. No one can deny some measure of sympathy for the small tenant trying to earn a scanty living on a poor hill farm or croft, who finds his stooks of corn in October or November black with Grouse. The crop may be well - nigh worthless, but that makes the temptation all the greater to try 1 Chap. ii. p. 21. 2 Fur and Feather Series, " The Grouse," pp. 65-72. ^ ro " se ' KEEPERS AND KEEPERING 453 and get some benefit out of a disastrous harvest. The landlord should deal with such cases in a broad-minded spirit, his gamekeeper should be instructed to assist in keeping the birds off the corn, and any old cocks that he may shoot should be given to the tenant as a solatium for damage done. One form of poaching remains tb be mentioned, namely, the catching of live birds and the stealing of eggs with a view to selling them for the restocking of other ground. Catching Grouse alive is perfectly legiti- Netting mate where a man nets only the birds bred upon his own moor, or on a moor which he has rented for the purpose, but in some districts in stealm s- the north of England, notably in Cumberland, the practice has developed into an abuse. It is a well-known fact that certain small freeholders on the edge of the hill land who have no Grouse of their own take a heavy toll of the birds which visit their ground from neighbouring moors. 1 An example of the damage done is furnished by one of the Committee's correspondents, who writes as follows : " Owing to the present system of netting on small holdings, Grouse preserving in Cumberland is a snare and a delusion. To give an instance my moor in the neighbourhood of - , of about 3,000 acres, used to give a yearly bag of about eight or nine hundred brace and was worth about 500 a year to let, now two or three hundred brace, all shot in the first fortnight to save them from being caught in nets, with a rent of about 100 a year, represents the present return." The only method of checking this evil would be for purchasers to agree to boycott all sources of supply that are open to suspicion. Egg-stealing is not a very common form of poaching ; Grouse eggs travel badly, and the advantage of introducing fresh blood by the importation of eggs has yet to be proved. 5 The practical difficulties also are considerable. 1 The following passage is worth quoting : " The cause of offence may be only a tiny strip of some pasture, heatherless, Grouseless, perhaps not. worth sixpence an acre for any purpose but one. Its want of food and shelter may be so evident that birds seldom light on it, but they have to flv over it, and nets judiciously arranged and managed will, in the course of a season, capture a very large number of them, and do very great harm to the adjoining beats. 1 ' G. W. Hartley, in " Victoria History of the Counties of England, Cumberland," edited by James Wilson, M.A., vol. ii. p. 439. London : Archibald Constable & Co., Ltd., 1905. Vide also Fur and Feather Series, "The Grouse" pp. 76-77. 2 Vide chap. xxi. pp. 477-47!). CHAPTER XXI STOCK By Lord Lovat THE subject of Grouse stock management is a difficult one on which to generalise, owing to the varying conditions which affect the Grouse in different parts of the country. The question is, however, of so agementof much importance that it is necessary to attempt to lay down certain rules that are generally applicable, and at the same time to note the exceptional cases to which these rules do not apply. The first question which naturally presents itself is, What is the ideal stock which good Grouse ground should be capable of carrying ? in other words how The ideal many birds can be supported upon a given area of good heather ? Simple though this problem appears, a little consideration will show that no solution can be put forward applicable to all moors. It must be remembered that the number of birds varies with the locality, the heather, the climatic conditions, and migration. Also that even on any given moor the number is not constant, but alternates in succession with the autumn, winter, and spring seasons. Before entering into the conditions which govern and limit the number of birds, and before describing the measures which are recommended to keep the stock on a moor inside the margin of safety, it will be necessary to define the position more accurately by stating (1) Exactly what we mean by the word "stock." (2) Certain statistics, from which broad general laws can be deduced, applicable to specific areas of moorland. (3) Certain facts and figures gleaned from the records of individual moors. The term " stock " of a moor is used indiscriminately to mean both the number of birds on a moor in summer when the coveys are Meaning of term unbroken, and the number of breeding birds which eke out a "stock." precarious living in the late winter and early spring months. 454 STOCK 455 For the purposes of this chapter the term " stock " will be used in the latter sense only. It has been shown in previous chapters that it is in the early spring that disease invariably appears, it is therefore at that period, and the period immediately preceding it, that the question of numbers is of real significance. The reason for this is not far to seek ; during the months of May, June, and July the fresh young shoots of heather are probably more nourishing than at any other time of the year even the oldest and most useless Food con . heather is not without some food value. In July, August and dltlons - September berries are added to the Grouse's diet, and in the late autumn and early winter the seed or fruit of the heather is largely eaten. In fact it may be said that from the beginning of May to the middle of the following January the food supply, even on the worst moors, is almost inexhaustible, and during this period the ground is capable of supporting a stock far larger than it could possibly carry during the subsequent three months. If, therefore, a limit of stock is fixed for March and April, it is sufficiently plain that that limit can be carried with safety all through the year. While it is impossible to give any exact number of pairs of birds that a particular 1,000 acres will carry in any specified district, as this varies with such matters as climate, shooting, etc., it will probably be interest- ,, Statistics. ing to many ol our readers to learn that, broadly speaking, the number of birds to the acre is curiously constant over wide tracts of similarly situated ground. In Yorkshire and Lancashire there are exceptional moors which carry a pair of Grouse to 2 acres; but in the north of England, gt oc k f generally, one pair to 4 or 6 acres is considered a safe winter acrea s e - stock on fully -developed moors. In Scotland the proportion is about one pair to 8 or 10 acres, except on the west coast, where the normal winter stock is often only one pair to 20, 30, or 40 acres. This generalisation can only be regarded as true of the aggregate, and not of individual moors, and it must be borne in mind that the bags obtained will show a much higher ratio. In a normal season the bag will usually be about double the numbers of the winter stock, and in a very good year it may be possible to kill as many as five birds for every nesting pair. The similarity of results obtained by a comparison of bags on great stretches of moorland enables several important deductions to be made. 456 THE GROUSE IN HEALTH AND IN DISEASE (1st) That there are certain natural limitations, directly connected with the growth and density of the heather crop, which local conditions of climate, soil, etc., enforce in each district. (2nd) That while close attention may modify these natural limitations, even the greatest care cannot wholly eliminate them. (3rd) That given efficient keepering and supervision, and the control both of sheep stock and shooting, the majority of what are considered third - rate moors might in time be raised to the average of the best of the similarly situated moors in the same district. (4th) That in any locality, owing to the slow rate at which old rank heather can be converted into good feeding, the progress of a moor from bad to good is necessarily slow. From the consideration of these generalisations we may now turn to the Individual study of the following records of bags from individual moors which have been selected as typical of each main tract or district. moors. No. 1 Moor No. 2 Moor No. 3 Moor No. 4 Moor No. 5a Moor No. 56 Moor No. 6 Moor No. 7 Moor No. 8 Moor No. 9 Moor Brace 370 576 350 414 1,701 1,319 1,205 250 2,781i 316 425 423 472 420 W 758i 67 784 606$ 444 636 183 560 430 2 716" 474 801 913| 683 91 315 1,348 611 H 1,011 l,158i 1,306 1,829* 1,578 320 447 80 1,238 265 704i 1,315" 692 8,4814 1,674 660 880 704 892 259 411 126 480 810 1,774 465" 382 2,350 71 72 4,922} 4,365" 1,428 885 1,214 420 728 1,247 44i 973i 255 250 696 ... 450 1,643 480 454 1,2614 886i 1,063 1,361 205 780 455 1,267 232" 6 476J 2,487 1,540 248 1,155 60 160 600 175J 38 5,010 408 1,737 175 572 154 789 529 157 1,268 1,625 305 236 1,330 i 80 180 476 i,oioj j 370 410 1,184 5 617 232 395 j 1,309 303 3164 ) 1,567 146 158J ? 422 416 429} 785 528} No figures relating to the breeding stocks on these moors are available; but judging from the bags the following deductions may be made : No, 1 Moor. Three hundred to four hundred pair of birds appears to be the limit of stock the ground would carry in March. It will be noted that every time the bag exceeds one thousand brace disaster follows. STOCK 457 No. 2 Moor. An improving moor apparently able to carry three hundred to five hundred pairs of March stock in a normal year. No. 3 Moor. A very typical dogging moor with four hundred pairs of breeding stock a safe limit. No. 4 Moor. A small well-burnt moor note the rapid recovery from disease ; also that it is dangerous to approach five hundred pairs of breeding stock. No. 5a and 56 Moors. The records begin with the year 1866, and the disastrous character of the outbreaks in 1867 and 1873 are reflected in the bags. 1 The figures in column 5a fluctuate so greatly from year to year that it is difficult to estimate a safe limit for the winter stock probably about four hundred pairs. Column 56 represents the bags on the same moor from 1894; in this year driving was adopted as the only method of shooting the ground. The results of better stock regulation under the new conditions are shown by the figures. While there are no individual bags as large as in 1866 and 1872 the average bag has increased from four hundred and fifty-eight brace to seven hundred and six brace in spite of two very bad seasons. No. 6 Moor. A breeding stock of about six hundred brace would probably be a safe limit, quite favourable conditions in spring. No. 7 Moor. This is a large moor extending to about 25,000 acres, and probably capable of carrying a larger stock than might be supposed from the bags ; probably one thousand five hundred pairs would not be too large a winter stock. No. 8 Moor. Another large moor, or strictly speaking a collection of moors, on the same estate, extending altogether to 34,000 acres ; about one thousand five hundred to one thousand seven hundred pairs would probably be a sufficient breeding stock according to the condition of the heather in the early spring months. No. 9 Moor. About five hundred to six hundred pairs. We find that on each moor so examined there is a very clearly defined limit of winter stock which it is dangerous to approach and almost certain disaster to exceed, and that while in occasional years, owing to unusually favourable con- ditions, an exceptional stock of birds may be reared, there is a constant tendency for the stock to revert to the normal ratio for the district. The whole art of moor management depends upon a proper appreciation of this tendency, for if the stock be not reduced to the safety limit by artificial means, nature will 1 Vide also p. 477. 458 THE GROUSE IN HEALTH AND IN DISEASE inevitably intervene and will regulate the superabundance with such severity that it may be years before the moor recovers. With these considerations in view we may proceed to lay down the one great law of stock management, viz., determine the number of birds that the moor will carry safely in March, and irrespective of all other consideration kill the birds down to that limit. It is a very curious thing that while all are agreed that stock must be "hammered" in a good year, no real precautions are taken either to find out when a good year is coming, or when a good year has arrived. Nothing is more common than the case of the moor-owner who, after various rumours and counter rumours, at last makes a casual inquiry about Ascot week from his agent or factor as to whether there will be any birds that shooting season. By early July he has settled his Grouse - driving parties, and has selected his shots from his regular autumn visitors, with the sole change of perhaps adding a couple of specially good shots if the report is favourable, or eliminat- ing the names of certain guests in the case of the report not being satisfactory. Towards early August he finds his way on to the moor, and the keeper, who has probably often been found fault with for undue optimism, hints vaguely that there is a " grand appearance," or perhaps, if cautious, " more than the usual stock on the ground." It is not till the first week of shooting that the host at last realises that he has got an abnormal stock of birds. His visitors rejoice, but he himself knows that his prospects of sport for future years are seriously threatened. If he realises the full significance of the position he may attempt to fit in one or two additional shooting weeks late in the season ; Late those who have tried to get together an October Grouse drive will readily appreciate the difficulties of the task. Added to this he may not be favoured by fortune. The earlier shoots may be spoilt by wind or weather, the later shoots may be rendered abortive by the high gales of the equinoctial period, and by the indifferent marksmanship of a hastily collected team of guns. The result is a foregone conclusion. The moor remains insufficiently shot, and by the end of the shooting season no stroke of fortune can avert the risk of disease. In the case of the let moor in a big year the situation is even more serious. Let In the first place, the lessee has less favourable opportunities than the moors. owner for obtaining information as to the prospects of the season ; in the second place, he has even less chance of killing down his stock if they STOCK 459 are too numerous. He himself is often a fine shot ; but the same cannot always be said of his friends. The close-sitting bird of August 12th, or the reluctant "up- winder" in an evening drive, may be killed even by the novice; but once the birds get strong on the wing, or fly with any degree of rapidity, twisting towards the spaces between the guns, rather than following an owl - like course over the centre of the butt, a very different standard of marksmanship is called for. Such birds appear to be immune from all pellets except those in the very centre of the charge. If the lessee does not succeed in thoroughly reducing his stock by early September there is little hope of much being done in the later weeks of the season ; he has probably no great acquaintance amongst the " hardy locals," and he will fail to decoy his club friends from London to drive Grouse once the Partridge season has set in. To avoid this state of things, of frequent, one might almost say regular, occurrence on many moors, it is necessary to adopt certain practical expedients. The keeper should be instructed to get about the moor in the t- i Early in- earher part 01 the nesting season to ascertain what stock of birds formation is actually on the ground and whether they are healthy ; he should mark down nests on each of the beats, and report by the middle of June how many of these nests have hatched off, and with what results. The Grouse is a particularly hardy bird, and provided that the stock is on the ground, and the eggs have hatched out, it is possible to estimate with some certainty the probable stock which will be available for sport in the shooting season. The modern methods of Partridge management require that the keeper should know not only the number of pairs on each beat, but even the number of eggs laid in every nest. Such accuracy is not necessary for the observa- Grouse keeper. He should have a rough knowledge of the num ber ^ s "? n of aud of breeding pairs on his ground, and from these, by observation hatchin g- of the average yield of marked nests, he should be able to give a shrewd guess of the number of birds that should come to the gun. The result from hatchings varies much less than most people suppose. It takes a very bad year to reduce the average yield of a pair of birds below 3'5 of young brought to the gun, and only in very exceptional years does the average covey exceed 5 '2 of young birds. Many keepers will not readily undertake the responsible duty of estimating the probable stock ; but it is not really necessary that they should do so for 460 THE GROUSE IN HEALTH AND IN DISEASE provided they can supply the facts, the proprietor may make his own deductions, and in any case it is advisable that the keeper's estimates should be checked by his master before they are acted on. While in England there is some excuse for lack of knowledge of shooting prospects such ignorance is unpardonable in Scotland when the keeper can run his dogs over the moor in July. When it is certain that a good season is at hand it is probable that not only one moor will be good, but that all the neighbouring shootings will share in the prosperity. It is therefore advisable to pay no attention to the wise men who contend that frequent shooting will tend to drive the birds off the ground, but rather to let shooting party succeed shooting party until the stock of birds has been killed below the number which is generally left on the moor. How this is to be done so as to give the best sport and at the same time the most satisfactory results now falls to be considered. To enter fully into the respective merits of shooting over dogs Methods of . J shooting and driving from the point of view of sport, is outside the province Grouse. of this Report. There will always be those to whom the working of dogs, the study of nature, the finer arts of venery, and the quiet beauties of the moor will provide two-thirds of a day's enjoyment. It is impossible to deny the satisfaction gained from a pair of wide - ranging dogs perfectly trained under a keeper who is thoroughly conversant with his moor, and able to take advantage of every chance of wind or change of circumstance that the day may bring forth. Although the shooting may not be difficult, the sur- roundings, the assistance which each sportsman is able to give in manoeuvring the Grouse, the chance shots which fall only to the alert, the feeling of satis- faction afforded by each old cock that has been outwitted, the short rests, the cool springs, and the cunning cuts from one point to another, all help to make the day's sport difficult to equal, and impossible to beat. To those who are in the first flight of shots, who love organisation for its own sake, and have the latter-day mania for big bags and pleasures condensed into the shortest possible space of time, driving, on the other hand, will always claim the first place. It will be readily admitted that there are few more exhilarating moments than the beginning of the down-wind drive, the first half dozen birds neatly killed, the nearest of them lying stone dead 50 yards behind the butts, the STOCK 461 conscious feeling of being able to deal with the situation, and the excitement of watching the big pack neatly turned by the flankers and sailing in serried mass towards the very centre of the line. While opinions differ as to the pleasure to be derived from either method of shooting, the benefits conferred by each are not hard to detail. The great advantage of shooting over dogs is that the worst shot should be able to kill without wounding. Dogging where it is possible is an excellent method of regulating the stock in a bad year. It gives an opportunity to kill all the old birds and spare the young. It is possible also to "dog" carefully the outskirts of a Grouse moor without doing any harm to the central beats, and thus provide a means of killing the birds on those parts of a moor which are least effectively driven. In a good year, dogging is but a very imperfect method for getting on terms with the stock. The mere fact that the coveys are large means that May, June, and July have been dry and fine, that all the birds are from first hatchings, and therefore strong on the wing, and proportionately wild. By the end of the third week of the shooting season if the weather is fine, or earlier if August has been wet and stormy, the birds are nearly unapproachable, and long shots and wounded birds are the chief results of a day's outing. A further disadvantage of shooting over dogs is that single old cocks almost invariably escape. The walking powers of the parent birds of a covey are limited by the pedestrian ability of their brood, whereas the solitary old bird is subject to no such limitations. Without going into the details as to how the dogging moor should be worked, certain points may be mentioned which do not always receive enough attention. In the first place, it may be laid down as a rule probably an unpalatable one that in a bad year, when it is desirable to shoot old birds, one gun, and one gun only, should go out with each dogging party. If two guns go together the object of each shooter is to kill outside birds so as not to interfere with his companion's sport: if the shooter goes out alone his object is to kill the first- bird on the wing, in nine cases out of ten the father of the brood. Where dogging is the usual method of shooting the owner should work round the lower fringes of the moors towards the end of the season in order to secure as many as possible of the pricked or badly-feathered birds which have worked their way down to the grassier and wetter ground. In settled weather the high 462 THE GROUSE IN HEALTH AND IN DISEASE tops should also be well hunted or even stalked for the old cocks which have resorted to these supposed sanctuaries. The main advantages of driving are : (1) That it affords a means by which the stock can be killed down to a proper limit ; (2) That it tends to mix the coveys, and so prevents inbreeding ; l (3) That as the old birds are the stronger fliers, and usually lead the packs, it is certain that in the early drives a large proportion of these elderly undesirables will be killed ; (4) That provided the host has selected his guns well the death is assured of all solitary old cocks who risk their fortune over the centre of the line. While these advantages are to be credited to driving, certain items have to be put down on the debit side. Unless the butts are occasionally changed, tages of or the configuration of the ground makes it possible to get all the birds forward to the guns, it is certain that the birds rising nearest to the butts will be more severely shot down than those on the more distant parts of the beat. All experienced sportsmen have observed that in certain long drives, unless the wind is favourable, a large percentage of the birds first flushed escape to one flank or another, and that only a few come over the guns, while in other shooting drives the birds are flushed from high ground, and, even if they do unequally. ., , . . . come forward, are secure from harm, owing to the height at which they fly. The circumstances repeat themselves each time the ground is driven, and become intensified year after year as the birds profit by experience, with the result that on every beat there are certain tracts of ground which form a sanctuary, while other tracts are overshot. It may be said that the over- shooting of certain tracts is, relatively speaking, not important, for if one portion is overshot it will quickly be restocked from the other more heavily stocked areas. It is, however, very important that no portion of a moor should be allowed to become a sanctuary, for this will lead to the survival of a race of old and useless birds, and thus reduce the annual yield of the moor. While driving is advantageous in a good year, it is a very difficult method by which to treat the stock in the years of recovery from disease. In a bad year the host and a few friends may shoot over dogs and agree only to kill able to bad old cocks ; they will be satisfied with a third of the usual bag if thereby they can bring the moor more rapidly into good order. To ask a party of guns, however, to drive Grouse, and either to refrain from shooting at the coveys, or only to pick out the old birds, is obviously impracticable. 1 Vide note by Mr Rimington Wilson, p. 480. STOCK 463 A great deal has been written, even by those in authority, to the effect that driving per se does not add to the yield of a moor. The Effect of Committee cannot endorse this view, and in this connection it would driving on not be out of place to trace the history of Grouse driving, and to study the results which have attended' its introduction in different parts of the country. Grouse driving was first introduced in Yorkshire, where, owing to the wild- ness of the Grouse in that country, it was found difficult to obtain a satis- factory bag by any other means. Naturally the innovation resulted J . J J Introduced at first in an increased yield, and this gave rise to an exaggerated from York- belief in the merits of driving Grouse as a means for increasing the productiveness of all moors. As a result driving was introduced on many moors where the same conditions did not exist, in other words, when the birds were not so wild as to necessitate this method of killing them. On these f . Driving not moors it was found that driving did not have the same satisfactory universally ,,.,,. -ii- i i beneficial. results as in Yorkshire, and that in some districts the bags obtained by driving were actually smaller than they had been in the old dogging days. Hence there arose a school of sportsmen who condemned driving as an undesirable institution, and never ceased to lament the fact that moors which were once good dogging moors had been converted into inferior driving moors, for it is well known that once a moor has been systematically driven its value for dogging is greatly impaired. The solution of the problem is perfectly simple. On all the moors, both in England and Scotland, when Grouse were naturally wild, the introduction of driving was followed by an increase both in the bags and in the stock, for the bags were increased owing to the increased facilities for bringing the birds to the gun, and the stock was improved owing to the possibility of killing off the old and undesirable birds, and leaving the younger and more vigorous to form a breeding stock. But once the system of Grouse driving had been fully established the improvement came to an end. Moors whose annual yield had been improved by several hundred per cent, ceased to improve when they reached the r J Benefits of higher level, for the beneficial results of driving had been exhausted, driving limited. The question is very fully discussed by Mr Teasdale-Buckell in " The Complete Shot." This writer draws attention to a condition which he describes 464 THE GEOUSE IN HEALTH AND IN DISEASE as one of " stagnation," which followed the establishment of Grouse driving. The stocks on many moors had been very much increased, it is true, but were no longer increasing. He quotes the figures from various moors in England in support of his argument, and gives examples of moors in Scotland which have not been improved by the introduction of driving. 1 Mr Teasdale-Buckell seems inclined to think that on the whole the records do not point to any great increase of stock as a result of Grouse driving. He probably does not give sufficient weight to the cases where it was followed by a very marked improvement, for these cases occurred chiefly in England as long ago as 1872 and 1873. He also does not notice that while the introduction of driving in Scotland in more recent years has not had such a marked effect, it has proved an effective method of regulating the stock in "big" years, and has tended to equalise, and, in the main, to raise the average yield on those moors on which it has been given a fair trial. There can be no doubt that driving has greatly increased the stock of Grouse on practically every moor in England, as may be seen by comparison of the records before and after its introduction. On many moors in Yorkshire, where before the days of driving Grouse had become almost extinct, they are now numerous. The true The beneficial effects of driving at Broomhead are fully discussed Grovwe f ^ n a no * e ^ v ^ r Ri m i n gton Wilson, which will be found at the end driving. of t hi s chapter. 2 Driving to be satisfactory must be efficiently carried out. It is a sine qud non that good shots must be chosen. Owing to the improvement in guns, and the amount of practice that can be obtained, few sportsmen are so inefficient as actually to miss their bird ; but there is a vast difference between the first- class shot who steadily kills four birds out of six, and the indifferent performer who only wounds a similar proportion. Difficult drives, that is to say, drives in which the birds either come at a great height or dip or curve over the line of butts, should be avoided unless masters of the craft are to form the firing line. Butts should not be too far apart 40 yards is a good average distance, and if this be taken as the maximum it will obviate the necessity of firing long shots, and at the same time allow a good performer to finish off the " tailored " birds of his next-door neighbour. The butts should also, where possible, be sunk so 1 "The Complete Shot," pp. 232-233. 2 Vide p. 480. STOCK 465 that the birds do not see the guns, and in consequence do not alter the pace and direction of their flight. The expediency of short sky - lines, the dis- advantage of having settling ground immediately in front of the butts, the proper use of "hill heads" for cornering the birds, and the general precepts for drivers, flankers, markers, pickers-up, ,etc., are all important, but do not fall within the immediate scope of this Eeport. Though moors should be disturbed as little as possible, it is a question whether the number of driving days on some of the fashionable moors are not being unduly reduced. The rage for big shoots, and the fact that it is difficult to get good shots unless big bags can be offered, probably prevents the full development of the minor driving days, whose main object is the improvement of the moor. On most moors great advantages would be gained by increasing the number of these minor driving days, and this might be done without disturbing the centre of the ground, for the off days might be devoted to the driving of outlying beats and high ground which at other times are never touched. If then it be admitted that, by means of driving, Grouse may be killed down to the required limit, the question arises as to the exact stock which should be left on each moor. There are certain general axioms which may be laid down with absolute confidence. The first and most important is that on a badly burned moor, where the supply of good winter feeding is small, the stock to be stock must left on the ground for the winter must be a light one. By good ^^er n winter feeding is, of course, meant the close grown six-to-ten-years feedin g- old heather which has already been described in an earlier chapter. 1 Con- versely on a moor where the heather has, by dint of severe burning, been brought into such a rotation as gives the largest possible proportion of winter feeding a much heavier breeding stock may be safely left. On Broomhead Moor, which may be taken as a typical example of a moor where the heather has been systematically burned for many years past, the ground is now capable of carrying a large winter stock without risk. On this moor of 4,000 acres from one thousand to one thousand five of winter stock to hundred brace is regarded as a fair breeding stock from which to summer obtain a bag of three thousand brace in the following season. In estimating the number of Grouse that should be shot the bags of 1 Vide chap. iv. pp. 71-72. VOL. I. 2 G \ 466 THE GROUSE IN HEALTH AND IN DISEASE previous years should be disregarded ; a moor which in the past has yielded an average bag of five hundred brace may in a big year produce one thousand five hundred brace and still be dangerously overstocked. It is the number left alive, not the number killed, that should be considered. It will be urged by many moor-owners that it is impossible to regulate the Grouse stocks with any precision, owing to the migratory habits due to of the birds. The objection is a pertinent one, and it is this migration. migratory habit of the Grouse which has so often defeated individual efforts at stock management. It has been pointed out in another part of the Report that in many districts Grouse annually move about in large packs, often leaving the high ground for weeks, or even months, at a time, and congregating on the lower moors. 1 When this occurs it is obviously impossible for a moor-owner to gauge the numbers of birds belonging to his ground which still survive the shooting season, for he may either find that every bird has left the moor, or alternatively that his own home stock is largely augmented by foreign visitors. In the former case it will be impossible to reduce his stock for the birds are no longer there to be shot ; in the latter case the packs are usually so large that any shooting that may be possible can make but little impression on the stock. The difficulty is further increased by the fact that it is usually late in the autumn before the seasonal migrations of Grouse occur, often after the close of the shooting season when no legitimate means are available for the destruction of the birds. Owners have always been ready to admit the principle that there is danger in leaving too large a stock, and some even go so far as to put the A large principle into practice by instructing their gamekeepers to kill down stocifun- *ke Grouse by systematic driving or " stocking " after the regular desirable, shooting has come to an end. This practice may result in the reduction of the stocks by a few hundred birds ; but is of little practical value unless it be carried out on a large scale throughout a wide district. Various r\ -\ i policies Other moor-owners adopt a neutral attitude. An owner of a high- lying moor will contend that he has nothing to fear from leaving a large stock upon his ground since the birds will migrate in the autumn to lower ground, when their numbers will be reduced either by shooting or by disease, and thus the stock will be brought to reasonable dimensions before 1 Vide chap. ii. pp. 25-26. STOCK 467 they return to breed in the spring. The answer to this argument is that if they are to be reduced by shooting it would be more profitable that they should be shot by himself than that they should go to swell the bag of his neighbour ; whereas if they are destined to become the victims of disease they may never come back at all, or if they do they may return as a decimated pest-ridden stock, quite unfit for the task of reproducing their species. In the same way the owner of a low-ground moor, where the Grouse have come to winter in their thousands, sometimes argues that it matters little what number of birds may be upon his ground in the winter, since they will return to their own higher moors for the nesting season, and will leave behind them a moderate breeding stock. These owners seem to overlook the fact that the presence of an excessive stock during the winter will most probably result in wholesale mortality amongst those that are left behind however reduced this remnant may be. The true explanation of the apathy of many moor-owners is that they have not the courage of their opinions. While admitting that in theory it is a dangerous thing to leave a big stock, they know that a big Temptation stock may, under favourable conditions, result in a record bag the farleTTreed- following year, so they take their chance, unmindful of the risk in s stook - they run, with the result that a good season which might be followed by another just as good often becomes the starting-point of a series of disastrous years. It may be laid down as a general rule that it is better policy to aim at a high average of bags, than to attempt to beat all previous records by leaving a large breeding stock. Stock regulation in a poor season is a comparatively simple matter, and requires but little judgment, no great risk is incurred by leaving the stock untouched, and there is not much temptation to over-shoot owing to the indifferent sport to be obtained upon an understocked moor, regula- tion. Sometimes it is true a moor may be overshot by an undesirable class of yearly tenant who is more intent upon getting value for his money than upon shooting the ground in a sportsmanlike way ; but this danger can be guarded against by a strictly worded clause in the agreement. It is only in a "bumper" year that the question of stock management becomes an urgent one. In places where the migration of Grouse is the rule, efficient regulation is 468 THE GROUSE IN HEALTH AND IN DISEASE impossible without co-operation among proprietors. It matters little that one moor-owner should kill down his birds to the limit of safety if there Co-opera- tion neces- are too many Grouse in the district, for other birds will crowd into "bumper" his ground from adjoining moors, or his own stock may migrate for the winter to some other district where there is already an over- stock. If, however, moor-owners would combine to reduce the stocks upon their individual moors the whole district would benefit. Each owner should make it his object to kill down his Grouse until only an average winter stock remains. The task will not be an easy one for in an exception- ally good season it is almost impossible to make any real impression on object to be the stock. There is little risk of over-shooting, for even if a proprietor aimed at. .... succeeds in killing every Grouse upon his ground it is quite certain that his neighbours will not be equally successful, and by the nesting season his moor will be more than sufficiently stocked by birds which had been crowded out from elsewhere. The Committee suggest that where a series of moors adjoin, and where Co-opera- * ne birds by migration are common in a sense to the whole range, the proprietors, with those of the shooting tenants who grasp the stock problem, should come to an understanding as to the best procedure for their common interests. It is suggested Firstly. That all should agree to get full information as to the prospects of the season at the earliest possible date, either on the lines already suggested in this chapter, or by any other means that may seem best to the individual proprietors or tenants. Secondly. That at some date early in July the interested parties should meet and agree whether the year is one in which the birds should be (i.) shot in the ordinary way; (ii.) shot heavily; or (iii.) really " harried." Thirdly. That arrangements should be made not only to kill down the birds on those moors where they are most plentiful ; but to make a point of shooting hard on the boundaries of moors which from slack- ness or bad shooting are likely to be lightly shot. Fourthly. That the local circumstances and knowledge gained from past experiences should be made known between moor and moor ; that arrangements be made for shooting all high ground specially STOCK 469 hard ; that " cheepers " should be universally exterminated ; and that the birds should be killed in October and November when they are massed on the low ground. While the Committee think it improbable that lessees could be got to combine together to shoot lightly in bad seasons there seems no reason why they should not agree to kill the birds hard in a really good year. The majority would welcome the opportunity for making a record bag, while an increase in the number of birds killed would improve the value of the moor to the landlord. In addition to regulating the numbers of his stock the moor-owner must also consider how the birds may be maintained in health. The practice of shooting down the stock severely .whenever the birds show signs of disease has long been regarded as an established rule of moor stook> management ; but it may be doubted whether the practice is justified. As a rule when birds are weak and thin at the beginning of the shooting r>j sease d season this is a sign that there has been an outbreak of disease in the spring ; but the birds that have survived the epidemic have reached the convalescent stage by August, and should be spared rather than destroyed, f >; they will probably be completely restored to health by November, and will be valuable as a breeding stock. This subject is fully discussed in another chapter. 1 The case is different when the bird is weak and undersized as a result of being hatched late. The common custom of sparing "cheepers" in order to give them time to develop as the season advances is one which ers " and late broods. cannot be too strongly condemned, for it is now believed that late hatched birds are a serious menace to the health of the moor. This real menace has never been sufficiently considered, but would appear to be one of the worst consequences of the loss of first broods, the full result of which is felt far more seriously in the succeeding year than in the season when it occurs. " Cheepers " of August are seriously handicapped for the remainder of their lives. They often apparently come on quickly during the shooting season, but are lacking in bodily vigour and hardness, and compared with the birds that were hatched in May and early June they feel the pinch of winter badly. The hens, exhausted by the double moult and the trials of nesting, succumb in the succeeding spring with untold loss to the moor ; the cocks, undersized and badly nourished by the end of winter, die in still larger numbers owing to the exhaustion consequent upon their efforts to procure and to protect their mates. 1 Vide chap. v. p. 128 (also chap. iii. p. 50). 470 THE GROUSE IN HEALTH AND IN DISEASE Late broods eventually become the most fertile soil for Strongylosis, which is always potentially dangerous even in healthy birds. This being so, V fllUG OI early it would obviously be desirable to encourage early nesting, and to save early clutches of eggs from destruction. There is, unfortunately, no possibility of encouraging birds to nest early unless by artificial feeding on a considerable scale ; but at least it is possible to avoid the loss of early nests which is so often the result of burning too late into April. Gamekeepers sometimes speak as though no harm is done if a few early nests are burned over, and as though the second clutches of eggs were every bit as good for the moor as the first hatchings. They may be so far as the shooting of that same season is concerned with good luck as many birds may be brought to the bag ; but for the succeeding season it is likely to be the worst thing that could happen, since it breeds weakly birds that will perhaps manage to survive an open winter, only to disseminate disease in the following year if they do not actually succumb to it themselves. There are, moreover, reasons, based on actual experience, why second clutches must always produce a smaller proportion of fertile eggs than first clutches. The following account comes directly from a well - known moor proprietor Evidence as to the result of hatching three clutches of eggs, each clutch mished consisting of the first eggs laid by three different hen Grouse. All I e a cond were consecutively " fertilised " by one and the same Grouse cock. The eggs had thus every possible chance, on the mother's side, of producing the full number of healthy chicks in every sitting. The first hen having paired off with this healthy two-year-old cock Grouse, sat and hatched ten chickens out of ten eggs. A second hen then paired off with the same cock, not immediately, but some time after the first hen had begun to sit. This second hen laid eight eggs, but only four were fertile, and four chicks only appeared. The same cock again, after a similar interval, paired off with a third hen which then laid eight eggs, but not one of them was fertile. Could there be stronger evidence for the superior value of a first clutch of eggs ? Under natural conditions the first clutch receives the full value of the cock bird with the best the hen can produce when in her best condition. Suppose that this nest is burned, or still worse, suppose that the hen has been sitting for some weeks, and is then forced to desert by stress of weather or disturbance by vermin. We have now, instead of a half-spent cock with STOCK 471 a hen at her best, a half -spent cock with a hen already exhausted and short of her stock of subcutaneous nesting fat to the extent of several ounces. She has produced seven or eight eggs weighing an ounce apiece, and she now produces half a dozen more. Not- only are these six eggs fewer in number than the first clui?ch, but they are almost certain to be not all fertile. And what is even worse there is the male element to be considered, and if, with the best possible materials in an unspent hen, his second effort at fertilisation is 60 per cent, less efficient than his first, what will it be when he has to deal with the resources of a hen already half exhausted ? The most certain way to avoid disease is to encourage the production of strong, early, robust, well-grown and well-fed birds that can meet and survive the privations of a hard winter, that can, if necessary, fly far afield for food, fight successfully, breed early, moult quickly, and put on new feathers without a check and without exhaustion ; such birds, if they are cocks, should weigh from 26 to 30 ounces, should have large red combs, full voices, and thick white-stockinged feet and legs ; if they are hens they should weigh up to 27 ounces, should moult rapidly and efficiently almost in midwinter, and after hatching out their broods should be fit to moult again without still showing bare legs and weathered plumage in the shooting season. And the other side of the question : " cheepers " too small to rise twice on August 12th, hardly three parts grown when the winter is upon them, bare- legged, and with a scanty growth of feathers replacing the chicken cheep- down, permanently undersized by the following spring, forced to mate ers- " with equally undersized fellows on the lower and less healthy beats where the food is soft and the water laden with the unwholesome washings of the hills around; beaten and often killed in their fights for the more desirable mates, they are forced later on to be content with the undesirable. One can imagine such a pair losing its first nest of eggs, and attempting a second. The hen is already a confirmed " piner " exhausted by the production of half a dozen eggs. If she attempts a second brood she is likely to succumb to the intestinal parasites that infest her. At the best, she appears in the August bag as a dull-feathered, shabby, undersized bird weighing 12 or 15 ounces instead of 22 or 24, or she is picked up dead with hundreds of others in April and May as a " piner " which has never bred. This is no exaggerated picture of the life of more than half the birds 472 THE GROUSE IN HEALTH AND IN DISEASE that are sent up for examination as "found dead" or "dying" in the spring, or as having been picked out of the bag in the autumn as unfit for food, or suspected of disease. They are all alike, undersized, poorly - feathered, desperately thin, bare-legged, and badly infested with every form of parasite within and without, and they are in consequence a very fruitful source of parasitic infection to the healthier birds around them, and a fertile soil for the cultivation and dissemination of disease. The birds referred to are definitely undersized, their bones are small and thin, their measurements are permanently below the average, they have ceased to grow as chickens when their autumn diet became a winter one, and by the end of October, instead of having enjoyed the full and varied supply of the five fattest food months of the year, they have had that of but three or four. Early hatched birds, on the other hand, are barely distinguishable from their parents by October, or even by September, and when winter comes they are prepared to meet it. They may grow temporarily thinner with starvation ; but they can never be undersized. Another question of importance in the interests of the stock is that of dealing with the old birds. The following remarks show how poor is the general opinion held con- cerning the value both of old cocks and of old hens. Stuart - Wortley in Fur and Feather Series writes: "It is my firm belief that the presence of these useless, and it is no exaggeration The useless- ness of old to say destructive, birds (i.e., old cocks) has a great deal to do with the scarcity of broods, and the low average of stock to be found on elevated Scotch shootings. " The older birds interfere with the matrimonial arrangements of the younger to the prejudice of the offspring. "The old barren hens are bad enough, but the old cocks are the worst, and both must by some means or other be destroyed. ... I would rather poison them than have them on my own ground. " In the pairing season the old warriors come down from the heights, fight with and vanquish the younger ones, and absorb the young hens ; the latter lay nests full of eggs, but they are sterile ; while the more youthful and capable cock bird, who would become the parent of a healthy brood, is either driven off the ground altogether, or obliged to remain in a state of combative celibacy. STOCK 473 "The old hen also, who is beyond the age of laying, attacks any young hen who may nest near her, driving her off her nest, thus causing the eggs to get cold, and the incubation to be abortive. " It is well known that in deer forests where the great object is to get rid of Grouse, the best means to arrive at this end is to leave them alone altogether. The result is that in a great measure they die out ; or at any rate their numbers dwindle to the lowest possible point." So also Mackintosh of Mackintosh makes the following statement : A " matter of vital importance is the killing down of old cocks. 2 " Another trouble results from the presence of these useless old cocks, namely, over-sitting. Probably if one chicken hatches the mother leaves the rest of the eggs, and so though the brood is lost it cannot often end in the bird's death. But when a whole nestful of unfertile eggs has been laid the hen may continue to sit long after the time when a brood of chickens should have appeared, and may even be found on her eggs dead from exhaustion and disease." All the views expressed above are fully endorsed by the Committee. There is no doubt that old birds are a danger to a moor, and tend to the degeneration of the stock, for not only are they more pugnacious than the younger birds, but they do not produce such large coveys nor such robust offspring. All moor-owners who take an interest in the improvement of their stock make it a rule to ascertain as nearly as possible the proportion of Proportion young birds to old upon their ground, and whenever they succeed in of old birds reducing the proportion of old birds the stock is found to improve. One of the Committee's correspondents has made a series of observations upon a moor in Inverness-shire extending over a period of thirteen years. His analysis of the Grouse stocks and relative bags is so interesting that the Committee have obtained his permission to publish it in this Report as an example of how stock may be recorded for purposes of comparison. The analysis will be found on p. 474, and in the letter which accompanied it the following passages occur. " I now enclose table showing nearly all the information I have as to old and young birds for a series of thirteen years. " As nearly as possible the moor has been shot in much the same way, and the same keeper has been in charge the whole time. "An effort has always been made to bag as many old birds as possible 1 Fur and Feather Series, " The Grouse " p. 148. 2 Ibid. p. 157. 474 THE GROUSE IN HEALTH AND IN DISEASE ANALYSIS OF GROUSE BAG FOU OLD AND YOUNG BIRDS FOR THIRTEEN CONSECUTIVE YEARS. Dogging Results Prior to August 12th. Year. How Killed. Birds Bagged. Old Birds. Young Birds. Ratio of OM to Young. General Total Ratio. Bag. Remarks. Coveys. Young Birds. Ratio. 1897 /Over dogs (Driving 1166 696 458 341 708 355 100 : 154\ 100 : 105 / 100 : 133 1862 No results kept 1898 1 Over dogs (.Driving 1098 764 364 310 734 454 100 : 202\ 100 : 147J 100 : 175 1862 No results kept 1899 /Over dogs I Driving 966 805 ! 417 325 549 480 100 : 1321 100 : 148 / 100 : 140 1771 No results kept 1900 /Over dogs (Driving 782 763 311 413 471 350 100 : 151 \ 100 : 85/ 100 : 114 1545 No residts kept 1901 /Over dogs (Driving 870 807 358 377 512 420 100 : 143\ 100 : 112J 100 : 1-2.1 1677 128 499 2 old to 3-9 1902 /Over dogs (Driving 798 412 378 275 420 137 100 : 111! 100 : 50j 100 : 86 1210 No results kept (Moor covered"! 1903 /Over dogs 244 t Driving i ... 158 86 100 : 55\ 100 : 55 244 with ice from 1 June 16th- f Nearly all barren pairs 19th J 1904 /Over dogs 651 (.Driving 311 272 143 379 168 100 : 1391 100 : 117/ 100 : 132 962 108 455 2 old to 4-21 . 1905 /Over dogs (Driving 758 573 277 216 481 357 100 : 174\ 100 : 1651 100 : 170 1331 145 793 2 old to 5-47 1906 f Over dogs (Driving 1067 896 389 319 678 477 100 : 174| . 1/50 ioq 100: 1501 ! 244 1163 2 old to 4-77 1907 /Over dogs (Driving 1387 967 479 412 908 555 100 : 190\ 100 : 135 / 100 : 164 2354 /Very wet I spring and 1. summer 299 1362 2 old to 4-55 young 1908 /Over dogs (Driving 1368 967 538 412 830 474 100 : 154\ 100 : 115J 100 : 137 2054 fSnow lay in"! - masses up till / 1 May J 235 lOfiO 2 old to 4-47 young 1909 /Over dogs (Driving 810 560 307 296 503 264 100 : 1641 100 : 90.1" 100 : 127 1370 1 Snow very i '. late on high 1 ground J 142 661 2 old to- 4-65 young Remarks. Since 1904 inclusive, an attempt has been made to run the dogs over every part of the moor prior to- August 12th, and the results are registered in the last three columns of above table. The exact number of barren pairs is not recorded in the figures, but all coveys are included. The whole of the moor is above 1,100 feet over sea level, and the best heather is about 1,200-1,500 feet. The aspect of the moor is about half south-west and half north-east. STOCK 475 both by selection and by driving all the high ground even above the heather line. Takino- the last six years it is curious to note that whereas the state of the moor as shown by dogs prior to August 12th showed on the average 4'68 young birds in each covey, or a ratio of old to young of 100 to 234 ; the actual recorded bag during the' same years showed 100 to 148. The very high proportion of old birds in the bag is, I believe, due to the following causes : " (1) That every effort is made to select old birds in shooting. " (2) That the inspection by dogs prior to August 12th does not include all the barren pairs. "(3) That before the driving takes place the young birds particularly pack, and so escape destruction. I have often proved that many packs consist of young hens." The analysis is interesting as showing that on the moor in question a larger percentage of old birds is killed by driving than by shooting over dogs ; but as the proportion of young birds throughout the season is invariably much smaller than would be expected from the observations prior to August 12th it is possible that the cause of this circumstance is that there has been a general migration of the young birds to lower ground before driving has been commenced. It would be interesting to compare the results of this high- lying moor with similar observations made upon a lower moor in the same district, and thus endeavour to solve the mystery of the disappearance of so large a proportion of the young birds seen at the beginning of the season. On a different type of moor the results would probably be entirely different, thus pointing to the need of adapting the principles of stock regulation to meet the special requirements of the ground. Many artificial expedients have been adopted for the improvement Artificial of Grouse stocks, either by raising their standard of health or in- i^p" s v n g creasing their numbers. Of these the most generally adopted is that of introducing fresh blood by importing eggs or live birds from other moors. It is believed by many moor-owners that by this means inbreeding and the consequent deterioration of the stock may be avoided. This view raises an interesting point in the natural history of the Grouse. There is no doubt that on some moors Grouse show a tendency to remain upon the ground on which they are bred, and do not develop the migratory 476 THE GROUSE IN HEALTH AND IN DISEASE habits referred to in other parts of this Report. The reason is usually Grouse not pretty obvious, for it is found that in the districts where the Grouse w hen the Grouse increased in numbers, it became necessary, on account of the labour involved, to move the coops less frequently, and it was found that moving them once a week was quite often enough. In that case, Supplying however, the birds had to be supplied with faggots or bunches of fresh heather. heather for food at least every two days, and, better still, every day. Later experience has shown that if these bunches of heather are tied in the coops with the tops of the heather hanging downwards the birds eat it just as well, and even better, than when thrown into the coops loose ; and the heather does not become soiled by the birds standing on it. Another important point is the water supply. All drinking water must be absolutely clean, and this has been ensured as far as possible by using Hearson chicken water-fountains, which prevent the birds from soiling the water. In 1906 very few Grouse were received. The results of the experiments on these birds were noted in Dr Seligmann's report. At the end of that season 1906 four birds were left : of these, two were unfortunately killed by a fox, GROUSE IN CAPTIVITY 485 leaving two, a cock and a hen, which were in different coops, the hen having been used for a simple experiment. In 1907 the hen began to lay, and laid ten eggs. Then the keeper put the cock into her coop and she laid nine more eggs, but at longer intervals between each egg ; out of these nine eggs she hatched four chickens. The remaining eggs were fertile ; but after the first four were hatched she became restless and left the other eggs. Of the four chickens hatched two escaped, and the other two grew up to be about three months old, when they died. This experiment was due to the keeper's initiative ; First but, having ascertained from it the possibility of hatching and rearing chicks - birds on the experimental area, it was decided that similar attempts should be carried out during the next season. During the year 1907, thanks to the exertions of those correspondents who kindly supplied the Committee with hand-reared Grouse, far more birds were sent to the Observation Area, and owing to the fact that there was no out- break of " Grouse Disease " that year, and that no birds were required for experimental purposes by the scientific staff, the Committee had in February 1908 twenty-seven healthy birds: of these two were the old birds sent in 1906. The remaining twenty -five birds consisted of eleven hens and fourteen cocks. Owing to the cock birds fighting, three were killed during the spring ; but precautions were afterwards taken to prevent deaths from this cause. The stock had now increased to twelve pairs of birds, so it became necessary to increase the number of coops. Six more large ones were added, and six smaller ones, which have proved very useful for the segregation of the birds during the mating season and also when the hens begin to sit, for it has been noticed that when Grouse are confined in coops the cocks will not leave the hens alone on the nests but are always driving them about ; as soon, therefore, as the hens commence to sit, it is necessary to take the cocks away and keep them in coops by them- selves. This year then the Committee had twelve pairs of birds. The hens laid very well, and the experiment was tried of taking the early eggs and putting them under foster-mothers but with fatal results. Two common hens F OS t er - of the ordinary yellow Orpington breed were set on twenty eggs each, mothers< and one on seventeen : one hen hatched seventeen chicks and killed them all ; the second hen hatched eleven and killed them all ; and the third hen ate all the eggs. Ten young Grouse from late laid eggs were hatched under Grouse mothers, and successfully reared. 486 THE GROUSE IN HEALTH AND IN DISEASE In the spring of 1909 a healthy lot of birds were left, and after the sad 1909. experience of 1908 with foster-mothers it was decided to let the Grouse hatch their own eggs. They nested well and sat well ; but again the Grouse as experiment was marred by two misfortunes. One hen was frightened !rs ' by a fox, and injured herself so seriously in her efforts to escape that she was found dead in the morning, and many of the nests being on low ground were washed out and spoilt by heavy thunderstorms just as the eggs were about to hatch ; still eleven birds were hatched and successfully reared. Thus in all, up to 1909, in spite of misfortunes, twenty-three birds had been successfully hatched and reared on the experimental area. And it must be remembered that the work really was experimental in every way, and every credit is due to Parker, the keeper, for the way in which he has carried out the experiments, for he had never seen Grouse till these birds were sent to him, everything Parker's na( ^ * ^ e explained to him, and the birds were kept under the most artificial conditions possible, both as to environment and climate. In 1908 and 1909 a number of Grouse were received from correspondents, and during both these years, and especially in 1909, a considerable number of birds were used for experimental purposes. At the end of 1909 it was found Change of tnat there were more birds left on the Observation Area than the keeper could attend to, and it was decided that if further accommoda- tion could be found some of the birds should be moved. Dr Paterson of the Frimley Sanatorium kindly offered to take charge of some of them, and in December 1909 six cocks and six hens were removed to the grounds of that institution, leaving six pairs on Mr Pain's ground with some birds that were being experimented upon. The birds that were removed to the Sanatorium were not put on such good ground as at Mr Pain's, and the conditions are far more artificial ; but they have done fairly well. The Grouse on Mr Pain's ground in 1910 were left to hatch out their own eggs, and did remarkably well. The number of chickens hatched is given at the end of this chapter. With those at the Sanatorium again the experiment has been tried of A second nate hing under foster - mothers, but it has not been a success ; not with one chicken was rear ed. If foster-mothers are to be used experiment f0 ot?T _ would show that the ordinary hen is too clumsy ; bantams might be more successful. GROUSE IN CAPTIVITY 487 The experiment has also been tried at Mr Pain's of mating one cock with two hens ; this also has not been a success. At first two hens were placed in one coop with a cock ; but it was found that this was a failure on account of the Mating one jealousy of the hens, the stronger and more pugnacious hen would never cock with ni r two hens. allow the other to receive any attention from the cock bird, and eventually one of the hens had to be removed. But it must be remembered that these two hens were confined with the cock in a small coop, and could not escape from one another ; a state of things altogether unlike their natural existence. Another method adopted was that of placing two hens side by side in two coops, and a cock was kept with them and placed in each coop alternately for forty-eight hours. One hen laid seven eggs ; the other laid four eggs, but would not sit ; the hen with seven eggs hatched one chicken ; the four eggs from the other hen were placed under another bird, and all produced chickens. For the information of those correspondents who may be desirous of rearing or keeping Grouse in captivity, it may be interesting to know how the Grouse have been fed. At first, of course, the feeding was largely experimental : as has already been mentioned the coops were placed where the Grouse could obtain fresh heather for themselves ; and it was extra- ordinary to see the way in which the birds ate the heather. Two birds on fresh in forty-eight hours would make the patch of heather contained within their coop appear as if it had been browsed by sheep. Later on the birds were supplied with faggots or bunches of fresh heather, and this was found to answer admirably, for at the Frimley Sanatorium there is hardly any growing heather, and the birds are for the most part kept on bilberry patches, with a few scraps of heather ; but they thrive well on their daily bunches of heather. In addition to heather the birds receive a mixture of grain ; at first this consisted of dharri, chicken rice, buckwheat, and feed millet ; but it was found they did not eat the two last, so now only dharri and chicken rice are given. Experience also shows that Grouse are very partial to fresh vegetables, especially lettuce. Attention has already been called to the necessity of a pure water supply, which is most essential. Another important point is grit. Grouse must have plenty of suitable grit ; the best and most natural is white quartz. The Grouse on the experi- mental area have always been supplied with plenty of this grit through the kindness of Sir Watkin "VV. Wynn ; without this they could not have been 488 THE GROUSE IN HEALTH AND IN DISEASE kept in health. Grit must be supplied from the earliest stage of the bird's existence ; it has been found in the gizzard of a Grouse chick not forty-eight hours old. When quite young Grouse will thrive on hard-boiled eggs and young heather, but the best food for them is fresh ants' " eggs " ; care must be taken not . . , > young to give the ants as well as the " eggs." The method pursued on the experimental area to get rid of the ants is to put the nest in the oven for a very few minutes ; this kills the ants, but does not seem to hurt the "eggs." 1 The birds on the experimental area have remained in splendid condition and plumage. During the four years deaths have been rare among them and have generally been due to accident or misadventure ; the old birds of 1906 are still there. Some birds become wonderfully tame, but others seem always to retain their natural wildness ; the cocks, as a rule, are bolder, and become tame sooner than the hens. Most of the male Mating birds resent any interference in their matrimonial arrangements, and time. their resentment is shown in many interesting ways. On approaching the coops the cocks at once begin to crow, or rather talk ; some will mount on the little faggots of heather supplied for food, and strut, and talk, and crow, swelling out their throats, elevating their supra-orbital combs, drooping the wings and fanning out their tails, as if defending their wives the whole attitude denoting readiness to fight. In fact, one of the birds has been known at the mating time to follow the keeper's wife (to whom he is usually very attached), out of his pen, pecking at her as hard as he could ; while the oldest cock of all, usually quite tame, will always attack the keeper if he enters the coop when the hen is on her nest. As the birds can be observed at a very close distance the plumage can be studied ; and the way in which the wings are carried, and the peculiar fan-shaped form of the tail during the courting process, is well worthy of observation. Mention has been made of the necessity of constantly changing the ground on which the coops are placed ; the more often this can be done of course the Fresh better for the birds. But it is only fair to say that for the purpose fiwa"^ 110 * f cer tain experiments some of the birds were kept on the same essential, ground for months, and it did not seem to do them the least harm ; they remained all the time in excellent health and plumage. 1 Really the pupae of ants, popularly known as " ants' eggs." GROUSE IN CAPTIVITY 489 Attention may be drawn to one very important point. It would naturally be thought, that, because the climate of Surrey is warmer than that of the northern parts of the British Isles, where Grouse live in a state of Nature, the Grouse on the experimental area would nest earlier than the wild Late birds. The exact opposite is the rule ; every year it has been noticed nestin s- that the Surrey birds lay and hatch later than Grouse in their natural state. There are several reasons to account for this. In the first place, under the conditions existing on the experimental area the birds are artificially and not naturally mated, and this alone may account for late nesting. It is possible, and very probable, that more extended experiments on mating hand-reared Grouse, in the same manner that Partridges are mated in captivity, might lead to earlier nesting ; but it has not been possible to make this experiment on the Observation Area. Again the necessity of the constant appearance of the keeper at different times may make the hen more shy of nesting, and the small dimensions of the coops, keeping the two birds always together, certainly is not conducive to privacy for the hen. So that those who try to keep Grouse and rear them on the lines adopted at the experimental area, must not be disappointed at getting late eggs. But, on the other hand, the results obtained on the Surrey area show that it is within the bounds of possibility to keep Grouse in captivity, and to rear from them 'in such a manner as to enable owners of Grouse moors to replenish by reared birds any loss their moors may have sustained from excessive mortality in a very bad season. Experience shows that it is better to allow the hen Grouse to hatch her own eggs, and not to place them under foster-mothers unless a supply of bantams could be obtained. Results of the Experiments. In 1906 two birds were left. In 1907 by chance four chicks were hatched. In 1908 tried hatching under foster - mothers and lost fifty - seven chickens and eggs; but reared ten late birds under Grouse mothers. In 1909 left the Grouse to hatch their own eggs ; a thunderstorm spoilt most of the nests only eleven birds were reared. In 1910, at Frimley Sanatorium, all eggs under foster-mothers hatched, but the chickens were killed by the hens; probably bantams would be preferable 490 THE GROUSE IN HEALTH AND IN DISEASE as mothers, and the sort of bantams that would be most suitable would be "Silkies." At Mr Pain's ground, where the Grouse were allowed to hatch their own eggs, the results obtained were very remarkable when compared with the results obtained from eggs placed under foster-mothers. Grouse Hens. No. of Eggs. No. of Chickens. No. 1 7 7 ,,2 11 9 ,,3 9 7 ,,4 7 6 5 12 11 ( -.A f Put under a foster-mother -j I who ate all thje eggs 7 7 8 4 One chicken ; other eggs not good. Would not sit ; eggs put under No. 5 all fertile. Hens Nos. 7 and 8 had one cock bird between them. No. 8 would not sit, so her eggs were put under No. 5, and all proved to be fertile, and hatched. Out of forty chickens hatched out seventeen have died ; all the rest of the birds are healthy and strong. Those that died were all between four and six weeks old ; these birds were examined by Dr Fantham as well as by myself, and were all found to be suffering from Coecidiosis. Coccidia were chiefly found in the duodenum and blind caeca, but many of these young birds also presented symptoms of pneumonia ; in these birds we both found coccidian oocysts in the trachea, the bronchi, and the bronchioles. It is <^aite possible that these coccidian cysts in the bronchioles would be capable of setting up sufficient irritation to account for the pneumonic symptoms observed in the lungs of such young birds. It would seem therefore that the old name of pneumo- enteritis, which, as applied by Mr Tegetmeier and others to one of the diseases that caused mortality in Grouse, has met with great criticism, may after all be proved to have some foundation in fact. CHAPTER XXIII THE VALUE OF GROUSE SHOOTINGS IN GREAT BRITAIN By A. S. Leslie THE Committee have obtained much evidence regarding the value of Grouse shootings both as a form of property and as a means of livelihood to a rural population. Statistics on the subject have never before been collected, and as the opportunity may not occur again the Committee venture to place on record the results of their inquiries. It is difficult to obtain accurate returns of shooting rents, as the figures fluctuate from year to year in sympathy with the prosperty of the community and the character of the season. There are, however, certain ascertainable facts which make it possible to arrive at a very fair estimate of the average return to be expected, and these facts it has been the task of the Committee to collect and arrange in the form of statistics from which a general deduction can be made. Grouse shooting is of all forms of sport the most profitable to the general population, it causes little clashing of interests between the sportsman and the pastoral or agricultural tenant, while the policy to be adopted ^^ for the scientific management of moorland is equally beneficial to profitable both. It produces a maximum of profit to the wage earner com- . ... munity. with the minimum of waste, an otherwise unproductive subject is converted into a source of profit, and districts which but for the Grouse would be uninhabited, except by a solitary shepherd, are occupied by shooting tenants and the men employed by them, and the tenure of many small and otherwise uneconomic agricultural holdings is thereby rendered possible. In connection with all moorland sport one point stands out prominently the land which is suitable for Grouse is not well adapted for anything else except sheep and cattle. But the pastoral value is in no way impaired by the presence of Grouse, for Grouse and sheep are found to flourish ground of small value together on the same hillside, indeed the flock-master is often under for agri- _ culture. obligations to the sportsman for the labour which the latter expends upon the burning and draining of the moor. 491 492 THE GROUSE IN HEALTH AND IN DISEASE It has been stated that land which is at present given up to Grouse might profitably be reclaimed and utilised for the support of an agricultural population. Experiments have often been made. In the county of Sutherland alone over 100,000 acres were apportioned among an industrious class of agricultural tenants with a view to being brought under cultivation ; but the experiment was a failure, and the land gradually reverted to its former state. The best Grouse ground, that is ground that grows nothing but heather, is always of a poor peaty nature, and is incapable of growing crops to advantage. In this respect it differs from the green land where the soil is rich enough to grow grass and bracken ; this green land is of little value for Grouse ; but might with advantage be planted with trees or even crops. It is probably true to say that in the selection of waste land for cultivation good Grouse ground is the last that would be chosen by practical agriculturalists. It is proposed to deal with the present subject under three headings : (1) The direct value of Grouse shootings to the proprietor. (2) The direct value to gamekeepers and other employees. (3) The indirect value to the community, Under the first heading the obvious difficulty which presents itself is that of putting a definite letting or selling value upon a given area of Grouse moor. Not only does the yield of Grouse vary considerably according to the district and to the management of the moor, but it has been found that the rents offered for this form of sport depend greatly upon the convenience or amenity of the district. In a district where the scenery is fine, and the climate bracing, a large rent will be readily given for a shooting which in a less attractive district would scarcely command a tenant. It is, of course, impossible to make an accurate estimate of values which depend so greatly upon circumstances and personal taste ; but an approximation can be made by dividing the Grouse- producing areas of the kingdom into districts possessing characteristics in common, and in which the average rent is recognised to be at a certain rate for a given average bag. This rate varies between 1, 10s. or even 2 per brace in some districts, down to less than 1 per brace in others. In each district the average yield of Grouse per acre of moor can be ascer- Yieid of tained from the annual bags of a large number of shootings of known iigiven f0r acreage. The total number of Grouse killed each year in a given area. district may thus be approximated, and the probable rent may be calculated at the current rate per brace for the district. VALUE OF GROUSE SHOOTINGS IN GREAT BRITAIN 493 The second difficulty in arriving at a correct valuation of Grouse shootings is that in the majority of cases moors are let with houses or shooting lodges, and one rent is paid for both. It is impossible to say what proportion g hooting of the rent is applicable to the shooting and what proportion to the lod s es - residence. The important point to ,note is that but for Grouse the shooting lodges would never have been built : and if Grouse shooting were to be dis- continued the lodges would become vacant, and the outlay incurred upon their construction would be wasted. This being so, it seems right to credit the Grouse with the gross rent paid ; but it may be necessary, in order to arrive at the net rent, to deduct a sum to represent interest upon the outlay on building. A typical example of a moderate-sized Grouse shooting would be one rented at, say, 600 for a period of three months. For this the tenant would probably expect to get, in addition to the shooting, a comfortable house with a garden, and the services of two gamekeepers. The rent might be apportioned as follows : Gross rent of furnished house and shootings . 600 House and furniture valued at, say, 4,000 initial cost interest thereon at 6 per cent. . . 240 Wages and allowances of two gamekeepers and one gardener, say . . . 150 390 Net rent of shootings above . . 210 The above sum of 210 would not represent the net profit to the proprietor, for he must deduct owners' rates and taxes, wear and tear of house and furniture, value of keepers' and gardeners' houses, cost of stocking the garden, etc. These items would vary according to circumstances, but in most cases it is doubtful whether the net profit from a rent of 600 would amount to more than 150 to 200. The above estimate is drawn up on the assumption that the Grouse shooting and lodge are to be regarded from a purely commercial aspect as an income- producing subject. But in many cases the house let with the shootings is the private residence of the proprietor, and would have to be maintained in any event, so that the whole interest upon the initial outlays and the expenses incurred for the maintenance of the house and garden cannot form a proper deduction from the shooting rent. In such a case the net profit from the shootings would probably amount to fully one-third of the gross rent received. 494 THE GROUSE IN HEALTH AND IN DISEASE From the statistics collected it is estimated that the approximate average yield from Grouse moors in Scotland is about nine hundred thousand Approxi- mate rent brace, and the average rent about 980,000 or, say, 1,000,000, repre- of Grouse . J r moors in sentmg a large proportion of the gross income from the ownership Scotland. ol land in the country. In a recently published work : the cumulo annual rental of Grouse moors in Scotland is estimated at 789,250 ; but the calculation is based on the assumption that the average rent of each moor is only 250, which is probably too low an estimate. in England ^ n England and Wales the average yield is estimated at three and Wales. nillic i rec i an( j twenty thousand brace, and the average rent at about 270,000. Owing to the difficulty of making an accurate calculation of the amount of the deductions referred to, the net rental cannot be very definitely stated ; but if it be estimated at one-third of the gross rental it'would amount to 333,333 or, say, 330,000 in Scotland and about 90,000 in England. The whole of this sum of net rental must be placed to the credit of the Grouse. It is true that in exceptional cases the residence or shooting lodge referred to might possibly be let during the summer months even without Grouse shooting ; but in that case the rent would not exceed 20 or 30 per month, or a total of 75 for three months. Out of this rent the proprietor would have to meet upkeep of house and garden, wear and tear of furniture, and interest on initial outlay. The deductions would amount to more than the gross rent, and the transaction would be unprofitable. In the majority of cases the absence of Grouse would make the shooting lodges absolutely unlettable even at a nominal rent. It is clear, therefore, that, in the interests of proprietors at least, Grouse shooting is of great importance, and on many estates, owing to the fall in agricultural rents and the increase of burdens, sporting rents form the main source of income. From the point of view of the employee the question is of equal importance. The census returns for Scotland show that the total number of gamekeepers employed in that country alone is over five thousand three hundred : Permanent employ- but of these it is estimated that at least a third are employed ment. _ i J upon low ground shootings, leaving between three thousand and four thousand as the number employed on Grouse moors. 1 " Grouse and Grouse Moors," by George Malcolm and Ayiner Maxwell. Adam and Charles Black, 1910. VALUE OF GROUSE SHOOTINGS IN GREAT BRITAIN 495 By another process it is possible to make a rough calculation of the number of men obtaining permanent employment upon the Grouse moors in Great Britain. On the smaller moors one gamekeeper usually suffices, but for moors of a greater area than 5,000 acres, or producing a bag of four hundred brace or upwards, it is usually found that a permanent under-gamekeeper is necessary. On the largest moors the number of men employed is smaller in proportion to the area, but on the other hand the rate of wages is higher. Generally speaking, it is found that the ratio in Scotland is about one gamekeeper for every two hundred and fifty brace of Grouse, and in England one to every three hundred brace, so that the number of gamekeepers obtaining permanent employment on Grouse moors would work out at three thousand six hundred in the former country, and one thousand two hundred in the latter country. After careful comparison of the statistics obtained from every Grouse- shooting district it has been found that the total wages and cash allowances paid to gamekeepers in England and Scotland is about wages paid to perma- 300,000 per annum, including tips. The details of the calculation nentgame- T > keepers. are not given as the methods of payment vary in different districts, thus making exact comparison impossible. Indirectly also Grouse shootings are responsible for a great deal of permanent employment. Gardeners, caretakers, and kennelmen are employed in connection with most shooting establishments, and their remuneration must go far to swell the total wage account; but owing to the different circum- stances which affect each case, it is almost impossible to estimate the annual wages paid to such extra employees. The addition of 50,000 or about one - sixth to the foregoing wage account would probably not be an excessive estimate, and the resulting sum of 350,000 should fairly represent the total annual wages earned by those who depend upon Grouse shootings for permanent employment. The apportionment of the rent of a Grouse shooting may therefore be roughly stated as follows : Net profit to proprietor about 34 per cent. Wages to permanent staff about 35 per cent. Cost of upkeep, interest on outlay, value of keepers' houses, wear and tear, rates and taxes, etc. about 31 per cent. Temporary employment during the shooting season has to be separately considered, for it does not form a deduction from the rent, but is paid by the 496 THE GROUSE IN HEALTH AND IN DISEASE occupant or shooting tenant. Such temporary employment consists of the hiring of watchers, Grouse drivers, ghillies, and pony men. The payment Temporary . . employ- received by a highland crofter as a pony man is from 16s. to 18s. a week, and 15s. to 20s. a week for his pony. In Northumberland the hire of ponies is 5s. per day, not including wages of the pony man. The shooting season extends over a period of about three months, and during that time provides well-paid employment for a number of people. The importance of this casual employment may be judged by the fact that in many remote parts of the Scottish Highlands a poor Grouse year, or the failure on the part of owners to let their shooting, results in an addition to the number of those who seek relief from the poor rates. In England, where practically all the Grouse are shot by driving it is not very difficult to estimate the amount of labour employed. Conditions, of course, vary on some moors the whole season's bag is obtained in a few days' driving, while on others the ground is driven oftener. But it is not found that this greatly affects the ratio of men employed, for in the former case the number of drivers will probably be larger than in the latter case. Generally speaking, a total bag of one thousand brace may be taken to represent, at least, three weeks' driving or, say, twelve days in all. If thirty drivers are employed each day at an average of 5s. per day, for men and boys the total wages paid would amount to 90, and this figure corresponds very closely with actual experience. From the foregoing calculation it follows that in England the estimated average annual bag would represent over 30,000 paid in wages to drivers. In Scotland it is not easy to estimate the proportion of the bag killed by driving ; but, if it be assumed to be one-half of the average annual bag, this would mean over 40,000 paid in wages. When the bag is killed by shooting over dogs the amount paid to ghillies and pony men must be considerably larger in proportion, especially on the west coast of Scotland, where the stock of Grouse is distributed over a wide area, and large daily bags are rare. Then twenty brace per day is considered good sport for a couple of guns, and the wages paid to ghillies and other attendants would work out at an average of over 2s. per brace. Making due allowance for possible error in the foregoing estimates it will be seen that the wages earned in connection with Grouse shootings must amount to a very large sum each year, and bear very favourable comparison with the net profit obtained by the proprietor. The indirect benefit derived by the community from the letting of shootings, VALUE OF GROUSE SHOOTINGS IN GREAT BRITAIN 497 though less obvious, is quite as important as the direct benefit. In every country district, both in Britain and on the Continent, the importance of the summer visitor is recognised, and every encouragement is given to the tourist traffic. Railway companies offer special inducements, dlstricts - hotels and lodgings spring into existence to meet the increased demand for accommodation, while landed proprietors and local governing bodies vie with one another to increase the amenity of their respective neighbourhoods with a view to attract the holiday crowd. Tradesmen, job-masters, proprietors, and even local charities, learn to regard the tourist as an important source of income. The value of the shooting tenant from this point of view is not so generally recognised, yet in the long run he certainly brings more money into the country districts than the tourist. To begin with, he usually belongs to a wealthier class than the average tourist, and his requirements are correspondingly greater. He brings with him indoor and outdoor servants, so that a remote shooting lodge may often contain as many occupants as a hotel in a tourist centre. But the principal merit of the shooting tenant is his wide distribution. Many people hardly realise that the regular tourist traffic is confined to a small space along the principal lines of communication and within easy reach of the necessities and comforts of civilisation. In Scotland especially only a very small area is materially affected by tourists and, though the motor car has opened up a number of remote districts where strangers were seldom seen before, these passing visitors are of no benefit to the community until they arrive again at a halting-place upon the beaten track. The shooting tenant, on the other hand, looks for his sport as far as possible from the main tourist routes, and usually at some distance from the centres of population : thus the area which has not been invaded by the tourist is occupied by the sportsman, and neither class interferes with the interests of the other. Many shooting tenants have endeavoured to calculate the indirect expense connected with taking a Grouse moor in Scotland, and the result of their combined experience seems to be that for every pound spent in rent from 15s. to 1 is spent on other expenses connected with the undertaking. In the recent work already referred to the indirect expenses are reckoned as equal to the rent. 1 Under this heading railway travelling, carriage of goods, cartridges, extra wages, dogs, household supplies, hiring and entertaining may be included. 1 " Grouse and Grouse Moors," pp. 28-29. VOL. I. 2 I 498 THE GROUSE IN HEALTH AND IN DISEASE Of the above the item of wages to extra keepers, Grouse drivers, etc., has already been dealt with. Many others do not directly benefit the local corn- Household munity, but the most essential of all, viz. household supplies is supplies. Q ^g u k mos t importance. It is true that some shooting tenants obtain many of their stores direct from London, but, even so, there are numerous necessaries of life, e.g., butter, milk, eggs, poultry, forage, meat, fish, mineral waters, etc., etc., which can only be procured upon the spot, and wherever there is a local tradesman within a reasonable distance of the shooting lodge he makes a point of catering for the sporting tenants on such lines as will secure their patronage. Probably more than half the household supplies are purchased in the district. So far as Scotland is concerned the average annual sum so expended would, on the basis of the gross shooting rent, amount to about 225.000, to which has to be added a further sum to include sundry payments for the hire of dogs and their keep, hiring of horses, carriages, etc., carting, and various other incidental expenses. Altogether the indirect benefit derived from the shooting tenants in Scotland cannot amount to less than 300,000, representing the circulation in rural districts of money which, but for the existence of the Grouse, would have been spent elsewhere, or not at all. In England the indirect benefit derived from the shooting tenant is less than in Scotland, owing to the fact that in the former country many of the moors are shot from a neighbouring hotel or country house, and it is seldom that a shooting party takes up its residence on or near the moor for any length of time. Still even in England incidental expenses are incurred for hiring, hotel expenses, supplies, etc., which might be reasonably estimated at a sum equivalent to 20 per cent, of the gross annual rental, making a total sum of, say, 50,000 spent in the districts. From the foregoing figures and estimates it will be seen that the value of Grouse shootings as a factor in the national prosperity may be stated in figures as follows : Gross rents received . . . . . 1,270,000 Gross wages earned ..... 464,000 Indirect receipts by the district . . . 350,000 2,024,000 VALUE OF GROUSE SHOOTINGS IN GREAT BRITAIN 499 Large as these figures are, they do not exhaust the list of benefits, for there are other indirect profits which it is impossible to state even approxi- . . . Building of mately in figures. The building, equipping, and maintenance of shooting shooting lodges alone must represent a very large sum paid into the pockets of local contractors and tradesmen. Lastly, it must be noted that the Grouse shootings of Great Britain bear a very large share of the burden of taxation. In the sparsely populated High- lands of Scotland the proportion is often very striking, for in some p aymen t parishes there are no towns or villages, hardly any agriculture, oftaxes - nothing of value but the sheep farms and Grouse moors. In such parishes it is often found that the value of the shootings amounts to one-half, or even three - fourths of the assessed rental. If the shootings lost their value the whole of this proportion would fall upon other interests. In "Grouse and Grouse Moors" attention is drawn to the benefits which accrue to the Imperial Exchequer by the issue of game licences, gun licences, and game dealing licences. The total amount of these licences in Scotland alone is stated at 34,166. of which nearly 30,000 is paid for game licences. From the foregoing brief summary it will be seen that Grouse shootings are an important item in the welfare of the country, and that it would be a serious calamity if anything occurred to impair their value. Yet from time to time legislation has been proposed which would strike a serious Mountains blow at this source of national wealth. The Access to Mountains Bill, which aroused so much controversy when it came before the House of Commons, received support from many urban members who did not realise its significance. If in the future any legislation on the subject should be introduced, much harm might be avoided by providing reasonable safe- guards. The solution might be found in the multiplication of rights of way, but in return the public should be expected to leave the moors undisturbed during the nesting and shooting seasons, and to refrain from wanton damage. Note on the Management of Sheep Stocks. The Committee has frequently been consulted by owners of Grouse moors as to the advisability of removing or reducing the sheep stock upon their land, with a view to improving the yield of Grouse. The subject is one on which it is difficult to lay down a general rule, owing to the variety of the conditions in different parts of the country. The following remarks must therefore be 500 THE GROUSE IN HEALTH AND IN DISEASE regarded rather as a summary of existing evidence than as an absolute solution of a problem which from its very nature admits of no universal answer. On those moors which are covered with heather, and which show no tendency Sheep ad- to rev ert to grass, a sheep stock is distinctly beneficial to Grouse, and on n heft e he"y severa ^ moor-owners have informed the Committee that in order to moors. maintain the full stock of birds they have found it advisable to re-stock cleared ground with sheep. The reason for this is not far to seek. The paths and small open spaces made by sheep form excellent drying ground for young birds. The hollows that sheep scoop out for themselves, in dry banks facing the sun, form admirable dusting places for coveys, and often add to the grit supplies of a moor. The heather growth is improved (1) by the sheep eating down the young heather, and so causing it to grow short and thick and form a close dense canopy which helps to resist the ravages of frost in spring ; (2) by their eating down the grass ; and (3) by their treading the surface of the ground, thus hardening it and preventing the growth of moss. It is also possible that sheep droppings may increase the number of flies and beetles on which the Grouse chicks feed so largely. The very fact that sheep and shepherds are on the moor is apt to be an incentive to extensive heather burning, while their presence acts as a deterrent to poachers. While all these benefits accrue from moderate sheep stocks, certain dis- advantages have to be reckoned with in all cases where sheep are allowed access to a moor. As has been pointed out in chapter xviii. in the case of old stick heather, the whole growth, and in the case of twenty-year old heather, a considerable portion of the growth springs again from seed after the moor has been fired. The tendency of sheep is to crowd on to the recently-burned patches for the young sweet grasses that grow there. The tender, slightly-rooted heather seedlings are pulled up wholesale and, if the stock of sheep is excessive, it may take years before the heather will once more assert itself as the dominant crop. 1 On land which has a tendency to go back to green ground, the control of sheep stock is an even more important matter than it is on the average heather-covered moor. in this case there is a risk, not merely of Sheep on grassy the return to heather being delayed, but even of the total extinction of the heather crop. Such extinction of the heather would be against the interests of sheep as well as Grouse, for it is well known that a certain 1 Vide PI. LVII. VALUE OF GROUSE SHOOTINGS IN GREAT BRITAIN 501 proportion of heather is an advantage on all sheep farms. Whether the ground which naturally goes back to green ground after burning is more profitably occupied by sheep, or by sheep and Grouse, is a matter which is outside the scope of this Inquiry, and each proprieter must decide the question for himself. If, however, the landowner does wjsh to keep both sheep and Grouse on his moor, he must make up his mind to one of two alternatives, either to reduce his sheep stock to such a limit as will enable the heather to grow after burning, or to fence temporarily blocks of newly-burned ground. On the subject of a stock controlled within reasonable limits, very interest- ing facts have come to the notice of the Committee, and without entering too far into the theory and practice of sheep farming, they feel they Control of have got enough evidence to satisfy themselves that not a few s heep sheepstock- runs, especially those occupied by a joint stock ("storting" or common grazing), would be benefited rather than injured by close control. Cases have come under the observation of the Committee, in which lessees of Grouse moors have leased the grazing rights in order to regulate the sheep stock, with the result that not only was the yield of Grouse increased, but also a marked improvement was effected in the health of the sheep stock. As an alternative to placing a limit on the stock, a practice has been adopted in certain districts in the south of Scotland, of devoting a separate farm or grazing to the ewe "hoggs" and "gimmers" before drafting theni (( into the breeding flock. This class of young sheep, like feeding wethers, is much less hard on heather than ewes, and there is evidence to show that ground devoted to " hogging," will produce much more heather than precisely similar ground carrying a ewe stock. The practice may be tried as a palliative when the heather shows indications of dying out, but it is doubtful whether "hogging" is possible except on the larger sheep farms of the Borders. On the subject of fencing newly-burned ground, a good many interesting experiments have been investigated by the Committee. The exact number of years for which it is necessary to fence areas of burned ground, and p enc ; n g the size of the patches which it is advisable to enclose (so as to burntareas> keep down expense in fencing, and at the same time not to cut off too large a proportion of the moor from sheep), must be suited to local circumstances. On an average area of hard moor ground where heather of not over twenty years has been burned, three years' enclosure from sheep is sufficient to get the heather seedlings fairly established. In the case of grassy ground, especially 502 THE GROUSE IN HEALTH AND IN DISEASE if old stick heather has been burned, this close time must be doubled. It is a mistake to keep the ground fenced for too long a time ; the sheep should be allowed to return as soon as the heather seedlings are rooted in the ground, otherwise there is a danger of moss growing up and choking the young plants. It will be found advisable, in order to save fencing, to fence square blocks chosen as a rule on ground which will rapidly come back to heather. Woven fences with iron standards which can be rolled up and shifted on pony back will probably be found to be most convenient. The size and number of the patches will naturally vary with the extent of the moor, and the amount of money that the owner is prepared to spend. It will probably be found better to enclose a few good-sized blocks of 6 to 20 acres rather than a number of small patches. Care should be taken to select the position of these blocks so as to suit the drives on the moor. All wire fences should be carefully bushed with heather, for experience shows that new fences are specially dangerous to the Grouse stock. INDEX (Note : "t," "" = " following" page or pages.) ACCESS to Mountains Bill, 499 Acclimatisation of Grouse, 1, 2 Accounts, Abstract of Committee's, ii. 19 ff Adimonia suturalia, see Lochmcea suturalis Age, methods of ascertaining, 62, 65, 66 Aleurobiim farince (flour-mite) on Grouse, 364 Alimentary tract, parasites in, 325 Amoeba lagopodis , 328 in fteces of Grouse, 328 staining, 328 schizogony, 329 encystment, 329 pathogenicity, 329 Anaemia, 118, 269 ; ii. 107 Anatomy, normal, 100 Anatomy in health and disease, 284-285 BACILLUS COL1, 200, 276-276 occurring post-mortem, 200 in liver, 282, 289 ; table, 290 f not associated with mortality, 200, 275, 297 relation to Strongylosis, 290 ff to Coccidiosis, 260, 295-297 to tapeworms, 293 ff Bacteria, carried by coccidia, 260, 295-297 Bacteriology, methods, 278 ff Bantams as foster-mothers. 489 "Becking," 21, 452 Berries, as food, 73, 74, 105 as grit, 98 seeds as vermifuge, 98, 99, 103 Bile, cultures from, 280 Bill, accidental injury to, 168 Blackgame, grit of, 99 accidental death, 158-159 remarkable series of deaths, 158-161 antagonism to Grouse, 177 heather beetle, eaten by, 424 " Blackhead," in turkeys, 268, 329, 330 Blaeberry, as food, 76 value of, 412 proportions eaten, 412 Blood of Grouse, 308 ff cultures from, 280 observations on, 308 ff Blood continued methods of examination, 309 staining, 309 erythrocytes, 309 leucocytes, 310 thrombocytes, 313 erythroblasts, 314 effect of helminthiasis on, 316 ,, of protozoa on, 314-315 ,, of Coccidiosis on, 251 eosinophilia in, 231, 316 bibliography, 317 Blood-counts, 314 tf normal, 314 pathological, 314 when Spirochceta lagopodis present, 314 ,, Leucocytozoon lovati present, 314-315 Eimeria (Goccidium) avium present, 315 in helminthiasis, 316 Blow-fly, see Calliphora erythrocephala Bolton Abbey Moors, 383 Bones, fractured and reunited, 153-164 Bracken, 400, 406, 412 crofter ponies and, 412 cutting, 441 Breeding, risks attending, 181 ff by last season's " cheepers," 459 loss of condition, due to, 471 Breeding-season weather of small importance, ii. 114, 120 Broods, early, value of, 470 ff ; ii. 130 late, 173 ; ii. 130 danger of late, 377, 469 ; ii. 121 diminishing value of late, 470 second, of small value, 470-471 experiments, 470 Broomhead Moors, 385, 401 effects of " driving " at, 464 breeding stock at, 465 notes on, by R. H. Rimington Wilson, 480- 482 " Bumblefoot" in Grouse, 170-171 " Bushing " of fences, 502 Butts, distance apart, 464 Buzzard, not destructive to Grouse, 450 503 504 INDEX C.ECUM, 105-108, 116 ff, 286 importance of, 109 obstruction of, 115 Trichostrongylus in, 116-117, 286 normal, described, 287 diseased, described, 288 csecal execreta, 107-108 ; ii. 91 cultures from, ii. 101 Calliphora eryihrocephala (Blow-fly) as carrier of coccidian spores, 262 Capercailzie, antagonism to Grouse, 177 Carron Moor, 387 Catechu, a specific in Coccidiosis, 269, 271 Cawdor Moor, 387 Ceratophyllus galtinulce, 362 garei, 363 Cestodes, 334 if chemical reaction of media necessary to, 105 not a cause of " Disease," 193 intermediate hosts unknown, 369 development of, 370 "Cheepers" and late birds, 469 ff should be killed out, 469 liable to " Disease," 471 fate of, 471 Claws, as guide to age, 63 Claw-shedding, 41, 46, 50, 63 Cobbold's theory of "Grouse Disease," 188 ff, 274, 390 Coccidiosis, 235 ff all " Grouse Disease " Strongylosis or, 204 may occur in man, 235 in rabbits, 235, 240, 242 f, 245, 254, 257, 296 in pheasants, 251 in fowl chicks, 253, 259, 260, 201 in turkeys" blackhead," 268, 329, 330 in young pigeons, 253, 261 in canaries, 269-270 in Grouse, 249 ff rarely fatal to adults, 231, 251 fatal to chicks, 10, 17, 36, 251, 261 affecting liver, 125, 259 duodenal, 241, 250 typhlitic, 241, 250 confined to digestive tract, 257 accompanied by anaemia, 269 symptoms, 249, 254 effect on weight, 140, 204, 255 ,, on appearance, 255 in hand-reared Grouse, 490 experimental studies, 252 ff infection, artificial, 252 ff ; ii. 103 ff natural (by water), 252-253, 261 associated with bacterial infection, 260, 296 blood-count in, 315 leucocytosis in, 251, 315 dissemination by insects, 246, 262 by birds, 268 iu dry weather, 263-264 ; ii. 120 preventive measures, 266 ff burning dead bodies, 251, 257, 267 heather-burning, 267 sanitary precautions, 267 treatment, 269 Coccidiosis continued catechu, 269 Coccidium (Eimeriu) avium, 235 ff habitat, 235 ff, 250 life history, 247 synonymy, 236 staining, 237, 242 morphology, 237 sporozoite stage, 238, 247 trophozoite stage, 239, 247 schizogony, 239, 247, 250-251, 257 merozoites, 240, 247-251, 257 periodicity, 246 gametogony, 241, 247-251, 257 encystment, 242 sexual differentiation, 243, 247 fertilisation, 244, 249, 257 periodicity, 259 sporogony, 245, 249, 250, 260 onset means recovery or death of host, 200 oocysts, vitality of, 263 effect of moisture on, 263 ; ii. 130 of drying on, 264 ; ii. 130 reagents destructive to, 264 ff effect on host, 249 on weight of Grouse, 140, 204, 255 as inseminating bacteria, 260, 295-297 insect carriers of, 246, 262 bibliography, 271 Coccidium cuniculi, see Eimeriu stiedte Coccidium oviforme, see Eimeria fttiedce Coccidium perforans, see Eimeria stiedx Coccidium tenellum, see Eimeria atiedce Cocks, old, killing, down, 389, 442, 481 uselessness of, 472 Collision with wire, 153 Committee, list of names, ii. 1 ff Corn feeding, 25, 81-82, 113 relation to disease, 178 ff injury from, 81, 82, 382 unusual effect on blackgame, 161 poaching and, 452 Correspondents local, list of, ii. 1 ff Crop, 101, 102, 111 never contains water, 102 inflammation of, 111 accidental injury to, 168-109 shot pellets in, 109 Crop contents, 67 weight of, 67 table of materials examined, 68 analysis of specimens from chicks, ii. 86-90 table of weights, 69 tables of contents, 70, 76 table of monthly averages, 79 chart of percentages of foods, 80 of Rvpe, 177 of Blackgame, 424 schedule of, of all specimens examined, ii. 27-85 Crossing of blood, 479-482 Crow, as vermin, 448 DAVAINEA CESTKILLUS, 341 morphology, 341 INDEX 505 Davainea ceiticillus continued rare in Grouse, 342 intermediate host, 342 .Dartiinett echinofiothrida, 339 lesions produced by, 339 similarity to tuberculosis, 340 economic importance, 340 Davainea tetragona, see V. echinokothrida Davainea urogulli (Lug Tapeworm), 334 ff effect on host, 113-11.5, 277 habitat, 105, 285, 334 in cseca, 290 post-mortem migration to cseca, 334 and bacterial infection, 290-295 and mortality, 295 seasonal prevalence, 297 ff morphology, 336 sexual organs, 337 intermediate host not discovered, 338 Dew, 94 Dew-pans, 389 Diarrhoea, " white," 259, 200, 268 Digestion, process of, 105 S chemical reactions in, 104-100 JHptera, parasitic, 358 ff " Disease," 185 ff, 444 (nee also Strongylosis) history of, 185 ff, 444 early records, 185-180 in eighteenth century, 185-180 former writers on, 147, 148, 185, 187 ff, 378 distribution of (maps), 187 ; ii. 137 ff no district free from, ii. 138 no periodicity of recurrence, 379 " years," 395 ; ii. 138 summary of problems, 149, 202 of conclusions, 150 ; ii. 140 relation to corn-feeding, 178 f William ("olquhoun's pamphlet, 179-181 John Colquhoun (" Moor and Loch "), 178 " Klein's Disease," 123, 188 ff, 194-200, 274, 379 not met with in Inquiry, 200, 204, 299, 379 Cobbold's theory, 188 ff, 194, 274, 390 other views, 188-197, 378-382 Tom Speedy, 181, 193, 195 Dr Andrew Wilson, 195-196 Tegetmeier's theory, 490 Committee's provisional view, 189-190, 199 ff final view, 204, 373 not due to tapeworms, 193 not due to Bacillus coli, 200, 275, 297 not due to " preservation," 185, 444 not connected with geological formation, ii. 139 due to Strongyle worms in caeca, 116, 204, 373 pathology, 273 ff cultures from internal organs, 279 f methods of examination, 278 ff effects of on sexes, 50, 51, 377 ; ii. 121 always causes wasting, 205, 277 relation to weight, 130, 135, 138, 140, 194, 277, 299, 377, 380, 471 undersized and late birds, 471 dissection a test for, ii. 138 no autumn outbreaks, 49, 51, 128; chart, 139, 455 artificial remedies for, 382 " Disease " continued relation to wet moors, 413 relation to rainfall, ii. 140 rapid recovery from, 477 sickly birds in autumn convalescent, 128, 469 Diseases, minor, of Grouse, 150 of skin, 183-184 Distribution of Grouse, 1, 3 Draining, 413 advantages of, 389, 413 ff methods recommended, 413 by gamekeepers, 440 to discourage heather beetle, 428 Driving, see. Grouse-driving Droppings, hard, 107 soft, 107, 180 ; ii. 92 "elocker," 110, 134 Drought, 16, 172 favours Coccidiosis, 264 unfavourable to Trichostrongylun, 233 Dung-fly, 360 ff as carrier of coccidian spores, 246, 262 not intermediate host of cestodes, 345 in Grouse droppings, 360 larvae, 361 morphology, 361-362 Duodenum, 103, 104, 284-285 habitat of small tapeworm, 104 effect of parasites on, 113-114 EAGLE, 19, 444, 449 Ectoparasites, 348 tf relation to endoparasites, 365 Eggs, number of, 8 depends on healthiness of stock, ii. 128 colour of, 8 intervals in laying, 8 size and colour, 9 effect of weather on, 9 ; ii. 128 of snow, 9, 10 ; ii. 129 of frost, 10, 11, 12 ; ii. 129 of wet, 9, 10; ii. 129 hatching of, 13 Egg stealing, 453 Egg changing, 479 Eimeria aviunt, see Coccidiwn avium Eimeria cunicu/i, see Eimeria stiedar Eimeriu fitlciformis , 240 Eimeria'. tchubergi, 236, 240, 249 Eimeria Medce, 240, 242-243, 245, 254, 257 Employees on Grouse-shootings, 495 Endoparasites relation to ectoparasites, 365 seasonal prevalence of, 298 Eo&inophilia in Grouse, 231, 316 Euston, or " Stetchworth " system, 439 Extra-uterine gestation, 183 FEEDING, hours of, 19, 20, 67, 109 during incubation, 110 Feet, accidental injury to, 167, 170 Fences, danger from wire, 20 "bushing" of, 20, 441, 502 Fencing of burnt areas from sheep, 501 506 INDEX Fighting, mortality from, 181 Filaria smithi, 218 Fires, accidental, 400 Flagellata, 325 Fleas on Grouse, 362 ff Flies on Grouse, 358 tf Flight, powers of, 26 Flooding, 15, 16 ; ii. 129 Food, heather nearly all-important, 70, 81, 398 ; ii. 129 but not indispensable, 69, 70 various, 70, 77, 84-87 heather seed, 74, 76, 153 ; ii. 129 berries, 73, 74, 455 insects, 77, 78, 88, 89, 90, 100, 369 corn, 25, 81,82, 113, 382 percentages in summer, table, 70 winter, nature of, 25, 75 greater quantity required in winter, 79, 132, 399 percentages in winter, table, 76 proportion of animal and vegetable, 90-91 chemical constituents, 100 monthly dietary, 83 ff Food areas, overcrowding on, 81, 136, 376, 379, 400 Food plants, list and description of, 83-87 Food supply heather burning and, 898, 400 conditions affecting stock, 455 relation of to migration, 81 Foreign species, introduction of, 53 Foster mothers, unsuccessful, 485-486 Fox, methods of destruction, 445 Fresh blood, introduction of, 28, 53, 475, 477-478 unnecessary where birds migratory, 477 birds apt to wander, 477 risks of introducing, 478 objections to introducing, 479 Frost, effect of on eggs, 10, 11, 12, 173; ii. 129, 132 . on pheasants' eggs, 11 ; ii. 134 Analysis of observations on, ii. 132 ff interrupting breeding, ii. 133 result of observations, ii. 136 GAM ASUS COLEOPTRATORUM (beetle-mite) on Grouse, 365 Gamedealers' licences, 452, 499 Gamekeepers, 430 ff importance of, 430 should be owner's servants, 430, 432 relations with agricultural tenants, 432 terms of service, 433 should not be paid in " kind," 433 married and unmarried, 433 pension fund, 4!!3 number required, 434 Head, 434-435 Under, 434-435 area under one man's control, 434-435 selection of, 435 essential qualifications, 435 personal qualifications, 436 Gamekeepers continued the " ideal " and the inefficient, 430-437 training of young, 436 importance of keenness in, 436 duties, 438 ff in "off" season, 438 in nesting season, 438 ff " Stetchworth " system, 438-439 improving nesting ground, 440 drains and springs, 440 grit supply, 440 vermin killing, 441 butt building, 441 " bushing " fences, 441 bracken, destruction of, 441 estimating stock, 441 observing nests and broods, 459 in shooting season, 442 ff Grouse driving, 436-437 cocks, killing down, 442, 453 Autumn heather-burning, 442 in Winter, 442 vermin tracking in snow, 443 total of wages paid to, 495 Game-laws Commission, 394 Game licences, economic value of, 499 "Gapes" in Grouse, 213 Geological formations in Scotland, ii. 139 no relation to " Disease," ii. 139 f Gizzard, 102, 103, 106, 111 in Grouse chicks, schedule of all specimens examined, ii. 27-85 floniodes tetruonis (bird louse) on Grouse, 348"ff habits, 349 morphology, 349-356 eggs, 356 and skin disease, 183-184 Grazing rents and sheep rents, 396 Gregarines in Grouse, 330 spores in alimentary canal, 330 Grit, 94 ff in Grouse chicks, 18 eagerly sought for, 20 size of, 95 weight of, 95 quantity of, 95 geological constituents of, 95 quartz, always preferred, 96, 97, 99, 102 garnets and glass beads rejected, ii. 94 f in partridge and pheasant, 96 artificial introduction of, 97, 440 during snowstorms, 177 ; ii. 94 effect of grit-starvation, 97 ; ii. 92 ff control over loss of, 97, 98, 114 ; ii. 92 ff berries as substitute for, 98, 103 in blackgame, 99 functions of, 100 shot pellets as, 103, 169 Grouse, history of name, 1 distribution, 1, 3 confined to Britain, 53 acclimatisation, 1, 2 economic importance, 2, 492 ff INDEX 507 Grouse continued systematisation, 2, 3 plumage, 3, 29 ff habits, 4 food, 4, 67 ff feeding habits, 19, 20, 67, 109 life history, 5 ff pairing, 5 pugnacity, G, 181 , nesting habits, 6, 7, 13 eggs, 8, 9 rare of brood, 14 dangers to chicks, 14 habits of chicks, 14 migration, 14, 15 wildness, 18 hardiness, 21 ; ii. 114 longevity, 28 minor diseases, 150 parasites, 347 resistance to disease, 376, 377 recuperative powers, 151, 153 effect of weather on, 9 ; ii. 128 f numbers vary with rainfall, ii. 140 methods of shooting, 460 ff netting, 453 economic value per brace, 492 (See under separate headings) Grouse chicks, 14 ff habits, 14 dangers to, 14 disappearance of, 14-16, 264; ii. 120, 124, 130, 132 drowning, 15 ; ii. 129 f food, 17, 18 insect, 88, 89, 90 vegetable, 90, 92 table of, 90 flight of, 19 liable to Coccidiosis, 261 " Grouse Disease " see " Disease " Grouse driving, 460 if advantages of, 389, 462, 480 disadvantages, 462 effect on yield, 463 history of, 463 results in England, 464 in Scotland, 464 rules for, 464 gamekeepers' duties, 437 management of, 437 heather-burning for, 404 minor days, 465 young and old killed by, table, 474 f crossing of blood by, 479-482 on Broomhead Moor, 480 wages paid for, 496 Grouse fly (Ornithomi/ia lagopodlt), 330, 358 ff morphology, 358 habits, 359 blood-sucking by, 330 carrier of protozoal parasites, 331 Grouse in captivity, 483 ff coops, 484 Grouse in captivity continued food, 484, 487 of chicks, 488 water, 484 grit, 487 mating experiments, 487 change of ground, 488 late nesting of, 488 Coccidiosis in, 490 Grouse moors, 393 of small agricultural value, 491-492 economic value of, 414 ff, 492 Grouse shooting ; in former years, 390 to regulate stock, 456-458, 479 no interference with agriculture, 491 indirect value of, 479 ff cost of, 498 methods of, 460 ff over dogs, 460 advantages, 4C1 disadvantages, 461 rules for, 461 young and old killed by (table), 474 driving, see Grouse driving Grouse shootings, value of, 491 ff economically profitable, 491 ground of small value, 491 f valuation of, 493 rents of, 494 employment on, 494-496 benefits to district, 496-498 summary of values, 498 Gulls, as vermin, 450 HJEltOPROTEVS MANSONI, 323 intermediate host, 323 Hand-rearing, 479 ff coops, 484 ; ii. 91 food, 484 water, 484 successful, 485 result of experiments, 489, 490 of grit starvation, ii. 92 ff infection with Strongylosis, ii. 100 ff with Coccidiosis, ii. 103 ff Hatching, date of, 7 period of incubation, 13 early, value of, 470 ff ; ii. 130 late, result of, on stock, 140, 173 on weight, 140 Hawks, not all are vermin, 450 Heart, 117 Heath, cross-leaved (Erica tetralix), 77, 84 Heather, hell (Erica cinerea), 84 Heather, common (C'alluna i-ulgaris) importance of as food, 70, 81 not indispensable, 69 old, as food, 77, 78, 399, 455 objections to, 408 uselessness of, 409 various types, 71 ff winter, 71, 175 dwarf, 71 short and long, 71, 378 508 INDEX Heather, common continued young, most nutritious, 72, 73, 465 ; ii. 129 culture, 72 growth from seed, 73, 400, 402 from root, 73, 400 seedlings eaten by sheep, 73, 402 and by young Grouse, 73 not by adults, 73 blossom, 74 seed, 74, 133 ; ii. 129 ripening of, 74 not eaten after January, 75 " frosted," 174, 378 term defined, 175 effect of frost on, ii. 130 good growth, effect of on stock, ii. 129 good grain year, good year for, 75 ; ii. 130 effect on of weather, ii., 128 burning, see Heather-burning raking, in time of snow, 176, 442 Heather-beetle (Lochmcea suturalis), 414 ff as causing "frosted " heather, 176, 414 ff, 423 ; ii. 124 former observations of, 416 f, 426 distribution, 414, 422 correspondence regarding, 415 ff types of heather attacked by, 415, 423 action on plant, 417 quantity to acreage, 418 records of damage by, 415-422 date of injury, 422 methods of search for, 417, 418 analysis of heather samples, 418 life history, 422, 426 ff incomplete, 429 nflueuce of climate on, 423 of rainfall on, 423 moisture- favourable to, 423 experiments with, 423, 426 ff, 429 eaten by blackgame, 424 methods of destroying, 423-425 morphology, 426 ff characters, 427 allied forms, 426 hibernation, 429 pairing, 429 Heather-burning, 392 ff, 443 history of, 393-396 " keeper's delight," 393-395 beneficial to both Grouse and sheep, 395, 405 f sheep-farmers' views, 405 f co-operation by shepherds, 406 in interests of landlord, 431 ,, of shooting-tenant, 431 to destroy " disease," 233, 397 to discourage heather-beetle, 403, 425 to foster healthy stock, 399, 431 ; ii. 131 for future years, 443 to provide food supply, 398 in interests of sport, 404 in strips, 401 large patches, 401 small patches, 396, 401 Heather-burning continued rules, 396 f, 406 labour required, 397 expense of, 409 areas, apportionment of, 399, 401 rotation of, 399-401, 407 estimating, 397 f, 408 measurement of, 399 example of scheme, 408 f choice of rotation, 408 methods of burning, 397, 401 ff burning against the grain, 402 back-firing, 402 second burning, 402 old and young heather, 400, 40(5 treatment of steep faces, 402 of flow ground, 403 of north slopes, 403 of knolls, 403 of peat hags, 403 of "grey" heather, 403 of burns and streams, 404 of " white grass," 411 of "green ground," 411 statutory seasons for, 404 " Spring " and " Autumn," 404 not after nesting begun, 470 Autumn burning, 404 ff, 44'2 periods of re-growth after, 408 objections to, answered, 409 Hedgehog, as vermin, 447 Ilelminthiasis, nee Tapeworms, etc. relation to weight, 143 blood-count in, 316 Hens, old, uselessness of, 472 Heterakis papillosa, in Grouse, 217 f common worm in poultry and pheasants, 217 synonymy, 217 " Hogging" effect on heather growth, 501 House fly, (Musca domestii-a) as carrier of coccidian spores, 262 Hymenolepis microps (Small Tapeworm), 342 ff habitat duodenum, 104, 10.5, 342 numbers present, 342 effect on tissues, 113-115 difficult to detect, 342 not directly associated with mortality, 294 nor with bacterial infection, 290-294 seasonal prevalence, 277, 285, 29" f effect on host, 113-115, 277 morphology, 343 sexual organs, 343-344 intermediate host not discovered, 344-346 IMMIGRATION of fresh stock, 476-477 evidence of, 477 Incubation, effect of on weight, 140 period of, 13 Insects, as food, 77, 88-90, 100, 369 ; ii. 86-90 parasitic, 348-360, 362 ff as carriers of coccidian spores, 262 Intestine, small, 104, 106, 115, 285 upper and lower portions, 105 habitat of large tapeworm (Drnwinea), 105 INDEX 509 Intestine, small continued inflammation of, 115 convolutions in, 10G Intussusception, 116, 122 Isolated moors, 478 Jxodes rivinus (Dog-tick), on Grouse, 363-365 as nymphs and larvue, 363 causing acute skin disease, 183-184 JACKDAWS, as vermin, 449 beneficial effect of reducing, 449 " Jugging," 21 KESTREL, beneficial, 450 Kidneys, 126 cultures from, 279 " Klein's Disease," 123, 188 ff, 194-200, 274, 379 not met with in Inquiry, 200, 204, 276, 299, 379 LATE shoots, 458-459 Leg-feathering, 31, 36, 40, 45, 49, 51 Leucocytozoiin lovati, 318 ff life history, 319 ff staining, 319 morphology, 320 ff gainetogony, 320 possible periodicity, 321 schizogony, 322 intermediate host, 322 association with Coccidiosis, 319 blood-count in, 315 Lice on Grouse, 348 iff, 356 ff (see Goniodeg, Nirmuii) Liver, 104, 106 f, 117 post-mortem changes in, 117, 125, 277 effect of Coccidiosis on, 125 not affected by Strongylosis, 125 cultures from, 280 Hacillus coli in, L'82, 289, table, 290 Lochnura nuturulis, see Heather-beetle Longevity of Grouse, 28 Lungs, 123 f poiit-mortem appearance, 123, 125 living parasites in, 124 cultures from, 279 MALLOPHAGA (Bird-lice), on Grouse, 348 ff Maps, showing incidence of disease, ii. 137 ff deductions from, ii. 140 Mating, experiments in, 487 Mesentery, 104 Migration, 25 ff seasonal, 6, 25 f, 382 wholesale, 25 f, 389, 46(i relation to food supply, 81 induced by heather-beetle, 414 affecting stock-regulation, 466 ff not universal, 476-478 as effecting crossing of blood, 476, 481 as re-stocking vacant ground, 477 Mites (Aleurobiux farinee) on Grouse, 364-365 Monocercomonas eberthi, see Trichomonas eberthi Monocystis up. , 330 spores in alimentary canal of Grouse, 330 Moor management, 372 ff defined, 377 examples of, 383 ff deductions from, 389 Mortality in April and May, 133, 140 in June and July, 36 seasonal, in cock and hen, 136, 140, 377 causes of, 147 ff accidental, 153 in blackgame, 158 from fighting, 181 Moult, 29 ff normal, 135, 137 deferred, 31, 37, 52, 182 of cock and hen different, 34, 43, 128, 137 of ptarmigan, 41 explanation of terms, 43 effect of disease on, 49, 127 effect of, on weight, 135, 137, 141 risks attending, 177, 182 Musca domestica (House-fly) as carrier of coccidian spores, 262 NEMATODES, non-parasitic, 375 larvae on heather everywhere, ii. 100 Nesting, 7 ff sites, 7 ; ii. 136 date of, 7 early, advantageous, 470 ; ii. 130 second, 471 strain of, 471 "Nesting-patch" on hen, 47, 48, 52 Netting Grouse, 453 Nirmus cameratux (Biting louse), on Grouse, 356-358 synonymy, 357 habits, 357 morphology, 357 eggs, 357 OBSERVATION area, 483 ff (Esophagus, 101, 111, 112 congestion of, 112 Old and young birds, 473 proportions in "dogging" and " driving," 474 Old birds undesirable, 472 f Ornithomyia lagopodis, see Grouse-fly Ovaries, 60 f, 127 effect of " disease " on, 127 Over-crowding on food areas, 81, 136 Over-sitting, 473 Over-stocking, relation to disease, 382 ff Oviduct, 61 effect of " disease " on, 127 Ojcyuris ambigua (nematode worm), 297 no relation to bacteria in tissues, 297 PACKING, 23 f, 25 reasons for, 400 in relation to age and sex, 475 Pairing, 5 effect of weather on, 5 effect of snow on, 5 sometimes postponed, 5 510 INDEX Pancreas, 104, 114 cultures from, 280 Partridges, methods of stock management, 439, 459 Peregrine, falcon, 448 Physiology, 100 ff of pigment production, 39 f Pigmentation, physiology of, 39 f of feathers, 37 f, 40 in relation to " wear and tear," 47 of eggs, 38 " Piners," how produced, 471 in autumn, 50, 129, 138, 182 description of, 139 in spring, 173 Plumage, 29 ff local variations of, 3, 4, 42, 53 ff in cocks, classification of types, 55 f red type, 56 black type, 57 white spotted type, 57 in hens, classification of types, 58 red type, 58 black type, 58 f white-spotted type, 59 buff-spotted type, 59 buff-barred type, 59 f abnormal variations, 60 uniformity the general rule, 44 seasonal changes, 29 ff in cock, 29, 34-42 "Winter" and "Summer," 29 effect of disease on, 30 f, 33, 127 f ( )gilvie-Grant's theory, 31, 34, 37 Millais's theory, 31, 37, 40 "eclipse," 32 ff, 37, 48 appellation inexact, 33 "Spring" and "Autumn," 32 in allied species, 34, 41 in hen, 38 f, 43-53 re-pigmentation, 37, 40, 128 Metchnikoffs theory, 37 as guide to sex, 62 as guide to age, 48, 63 Pneumo-enteritis, 490 Pneumonia, 123 f, 125 never observed, 200, 204, 276, 299 Poached game, facilities for sale of, 452 Poachers, 450 ff professional, 450, 452 occasional, 450, 452 prevention of, 451 in former days, 451 snaring on stocks, 451 " becking," 452 netting, 453 egg-stealing, 453 Poisoning, 169 f septic, in Grouse, 170 Polecat, 447 " Preservation -theory " of "Grouse Disease," 185, 444 Primary feathers, growth of, 64 f diagram, 64 Protozoa, 318 ff bibliography, 332 Proventriculus, 101, 106, 111 Psorospermium avium, see Coccidium avium Psorospermosis see Coccidiosis Ptarmigan, moults of, 41 RAINFALL, effect on heather-beetle, 422 relation to yield of Grouse, ii. 140 Raven, as vermin, 449 Rectum, 104, 106, 110 inflammation of, 116 Re-pigmentation of plumage, 37 ff, 46, 128 Metchnikoff's theory, 37 Millais's theory, 40 Rhizopoda, 328 (see Anueba lagopodis) Rook, as vermin, 449 Rotation, in heather-burning, 407 SCATOPHAGA STERCORARIA, see Dung-fly Scent, loss of while sitting, 13 Sex, methods of ascertaining, 60 ff in relation to plumage, 61 f to weight, 134, 140 ,, to packing, 475 Sheep, destructive to seedling heather, 73, 402 advantageous on heather ground, 500 may kill out heather, 500 fencing burnt areas from, 501 Sheep-drains, 15, 10!) Sheep-rents and Grazing-rents, 394 Sheep-stocks, notes on management, 499 control of, 501 Shooting lodges, 493 Shot, wounds from, 151, 153, 162 ff alleged poisoning by, 169 f Skin disease, 183 f Snaring on corn stocks, 452 Snow, effect on pairing, 5 on nesting, 10 ; ii. 129 on healthiness of stock, 22, 381 ; ii. 130 on migration, 6, 381 on heather, 176, 381 "jugging" in, 22 breaking of surface, 176, 442 vermin tracking in, 443 " Soft-shell," 183 Specimens examined, schedule of, ii. 27-85 Spirochtfta eberthi, see Trichomonas eberthi Spirochceta lagopodis, 323 ff staining, 324 characters, 324 schizogouy, 324 effect on host, 325 intermediate host, 325 blood count, when present, 314 Spirochceta lovati, 327 f staining, 327 in ceecal contents, 327 structure, 327 schizogony, 328 Spirochcetacea, 323-327 Sporozoa (blood parasites) of Grouse, 318-325 Spleen, 126 INDEX 511 Spleen continued as affected by Strongylosis, 126 cultures from, 280 Staff, list of, ii. 1 " Stetchworth " or " Eustou " system, 439 Strongylosis, 207 ff the " Grouse Disease " of adults, 116, 373 in normal birds, 118, 300 almost universal in Grouse, 196, 209, 286, 374, 376 Cobbold's discovery of, 188 ff a progressive ailment, 118, 376 due to vast numbers of Strongyli, 286, 376 occurs in cwca, 109, 111, 117, 219, 316, 377 pathology, 119 f, 230 ff, 273 ff, 374 effect on csca, 113, 123 post-mortem appearance, 286 ff inflammation and tibrosis, 289 effect on moult, 36, 50 f, 127 on spleen, 126 on reproductive organs, 127 no effect on liver, 125 affecting weight, 141, 194, 204 examples of, 121 f seasonal mortality from, 135, 141 recovery from, 120 toxosmia in, 109, 118, 301 helminthic toxins in, 208 relation to Jiacillun coli in tissues, 290 ff eotsinophitia in, 231, 316 blood-count in, 316 infection, artificial, 229 ff ; ii. 100 ff natural, 136, 232 f remedial measures, 231 relation to food supply, 232, 234 ; ii. 130 Strongylus pergriicilin, see Trichostrongylus pergracilis. Stoat, methods of destruction, 446 Stock management, 4.54 ff meaning of term, 454 statistics, 455 generalisations, 456 examples of typical moors (table), 456 f the " ideal," stock, 454, 467 in relation to acreage. 455 " Winter" and " Summer," 81, 455, 465 dependent on winter food supply, 455, 458, 465 ; ii. 131 ascertainment of, 458-459 regulation by shooting, 456 ff, 479 proportionate yield, 455 on let moors, 458 in good season, 460, 467 in bad season, 461, 467 methods, 460 ff healthiness to be considered, 469 ; ii. 129 and results of nesting, 459 migration as affecting, 466-468 policies sometimes adopted, 466 f necessity for co-operation, 468 rules for, 468 f objects to be aimed at, 468 large " Winter," undesirable, 466 methods of reducing, 466 maintenance of heather, 469 Stock management continued sickly birds in autumn may be spared, 469 " cheepers " should be killed out, 469 ff old birds undesirable, 472 ff proper ratio of young and old, 473, 474 artificial improvement, 475 ly fresh blood, 476 ff, 481 migration and re-stocking, 477 where Grouse non-migratory, 478 egg-shifting, 479 importing birds and eggs, 479 hand-reared birds, 479 summary of conclusions, 479 Subscribers, list of, ii. 10 Syngamus trachealis ("Gapes-worm "), in Grouse, 213 TAENIA CALVA, see Davainea urogal/i Teenia cesticilliis , see Davainea cesticillus Toznia microps, see Hymenolepis microps Tapeworm, see Cestoda Tapeworm, large, see Davainea urogalli small, see Hymenolepis microps Temperature (body), of Grouse, ii. 110 Tentsmuir, 93 ; ii. 139 Testes, 60 f, 126 f effect of disease on, 127 Threadworm, see Trichostrongylus and Trichosoma Ticks, on Grouse, 363 (see Ixodes) Toxaimia, 109, 118, 204, 301 Toxins, helminthic, 208 Trichomonas eberthi, 325 synonymy, 325 in csecal contents, 325 staining, 326 structure, 326 schizogony, 326 encystmeut, 326 Trichosoma longicolle, 214 ff synonymy, 214 less common than Trichostrongylus, 114 habitat duodenum, 104, 113, 217 structure, 215 morphology, 215, 217 pathological effect small, 217 but allied to to dangerous parasite in man, 217 Trichostrongylus pergracilis, 218 ff, 375 cause of " Grouse Disease " in adults, 116, 373 habitat cseca, 109, 111, 116 f, 219, 377 numbers present, 286, 316 methods of counting, 283 almost always present, 196, 209, 286, 374, 376 allied species, 207, 208, 212 f synonymy, 207 ff characters, 207 f life history, 218 ff, 228 f development, 218 ff within host (morula), 219, 375 outside host, 319 f artificial cultivation, 220 ovum, development of, 221 moisture necessary to, 226, 233, 375 effect of drought on, 233 embryo, structure of, 222 first eedysis, 224, 375 512 INDEX Trichoxtrorujylus pergracilis continued quiescence during cold weather, 233 metamorphosis, 224, 375 ; ii. 101 larvae, 225 encystment, 225, 375 migrations, 224, 375 on heather, 225-228 experimental administration of, 229 f, 374 ; ii. 100 ff effect of frost on, 232, 375 of drought on, 232, 375 of sea spray on, 375 ; ii. 139 maturity and reproduction, 229, 376 methods of destruction, 234 Trypunosoma eberthi, see Trichomonas eberthi UNDERSIZED hirds, 377, 472 VERMIN, 16, 177, 443 ff keepers' duties, 443 ff " balance of Nature," 443 sometimes beneficial, 445 vermin -killing and " disease," 444 tracking in snow, 443 methods of destruction, 444 ff golden eagle, 19, 444, 449 fox, 445 f stoat, 446 weasel, 447 hedgehog, 447 f cat, wild, 447 peregrine falcon, 448 crow, 448 rook, 449 jackdaw, 449 raven, 449 hawks, 450 gulls, 450 WATER-DRINKING by Grouse, discussed, 18, 93 f Water drinking continued by adults, 18 by chicks, 18, 472 in hand- reared birds, 4!!1 in sickness, 102 Grouse do not often die of thirst, 264 artificial supply, 93 f, 389 Weasel, as vermin, 447 Weather, 9 ff effect of, on eggs and young, 9 ; ii. 130 on nesting, 10 ; ii. 130 f on breeding, 12, 172 on chicks, 13 f; ii. 130 on health of stock, ii. 128, 130 on heather, ii. 130 Analysis of, during years of Inquiry, ii. 113 ff Weight of Grouse, 130 ff as test of disease, 130, 138, 140, 376, 380 ; ii. Ill as sign of health, 377, 442, 471 seasonal changes in, 130 ; chart, 131 effect of courtship on, 134, 140 of moult on, 135, 137, 141 of late hatching on, 140 of incubation on, 140 relation to disease, 135, 141 f, 277, 299 effect of Coccidiosis on, 140, 204, 255 ; ii. Ill of Strongylosis on, 141, 204 ; ii. Ill of Helminthiasis on, 142 conditions affecting, 140 f in relation to sex, 134, 140, 471 local variations in, 143 ; table, 144 f records, 146 " White diarrhoea," 259, 260, 268 Willow Grouse, plumage changes in, 41 crop contents, 177 Wing feathers as guide to age, 64 Wire, collision with, 153 Woods as shelter, 22 YOUNG and old birds, proportions of, table, 473 END OF VOL. 1. PRINTED AT THE EDINBURGH PRESS, 9 AND 11 YOUNG STREET. 14 DAY USE RETURN TO DESK FROM WHICH BORROWED This book is due on the last date stamped below, or on the date to which renewed. Renewed books are subject to immediate recall. npn JL"> 1965 HI " "'c-'oSSH IONo J 65JN General Library University of California Berkeley w