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 6 
 

THE FUNDUS OCULI 
 OF BIRDS 
 
THE FUNDUS OCULI OF BIRDS 
 
 ESPECIALLY AS VIEWED BY THE 
 
 C PHTH ALMOSCOPE 
 
 A Study in 
 Comparative Anatomy and Physiology 
 
 BV 
 
 CASEY ALBERT WOOD 
 
 ntulrattd by US drawing! m the text; alto by rixiy-ont 
 
 colored paintingt prepared for thit work by 
 
 Akthuk W. Head. F.Z.S. 
 
 LondotK 
 
 CHICAGO 
 
 THE LAKESIDE PRESS 
 
 1917 
 
CofTiiioiiT, 1!)|7, iir 
 CA!*KV AI.BKKT WOOD 
 
 - 
 
TABLE OF CONTENTS 
 
 I 
 
 II 
 HI 
 
 IV. 
 
 V. 
 
 VI. 
 
 VII. 
 
 VIII. 
 IX. 
 
 X. 
 
 XI. 
 
 XII. 
 XIII. 
 
 IfAUH 
 NTHOhlCTION 
 
 vS.MMA|lv or CoNfLlMIONH J 
 
 (:<.LLK( TIO.V. SkLWTION AND PnKPAHAT10.N<)r MaTK 
 MIAI, 
 HlHI.KKHIM HI 
 
 .\ Hkmf.w „r Tii»; .\natomy and Piiyhiolooy or the 
 OiuiASH AM> Tis.m t:., heks i.n the Fcndi ,« Ikvu 
 
 (>y TIIK HiKI) 
 <•• TMALM..Hr..l.V, „» TIIK KxAMISATK.N TllHOt (iH 
 IIIK I'ri'lLH. IN .\mmatK Si'K< IMKNs. of TIIK l.NTK- 
 moH UV TIIK \KHTKill(ATE KvK HV MeaNS OE THE 
 
 <)i'iiTiiALM()S(()ri: 
 
 «)i-iiTiiAiMo.s,.o,.v OK THK FiM). H IN L,v,N„ lUnns: 83 
 
 .\ rho Ky«-Krr>,iii(l in Ccncral 35 
 
 H The I'cctcii iiiiil Optic Disc gg 
 <'. TL.' .Macular UcKions, Fovea- anil otlicr .\rtNis 
 
 of Acute Viiioii . , jjg 
 I). The Fuiidal nioo.lvcys.-ls, the Opaqu.- \,-rvc 
 
 Fil)r.-s, the Choroid aii.l the lietina 38 
 
 K. riiolo^rraphy ..f the Fun.lus in I.iviiin Birds 44 
 •Ma. Kos< opic Api'eara.vc Es OK THE F urs OctLi or 
 
 UiHDs IN Phepaiied Spe( imens 49 
 
 l'hot..jfraphy of the Fundus in P red Eyeballs 01 
 
 fcKKE.TH OF D0MK.STICATION ON THE FlNW.S Ot ILI 
 
 OK Wild Spe( ie.s of Bihd.s qj 
 
 The Ophthauvio-scopic and Ma. Hos.i.Pt, Appeak- 
 ANCEH or THE FlnDUS Oil LI IN \ahiol.s <)hdeh.-s 
 or Birds. 
 
 A. Uutitip _. 
 
 B. Carinata- fls 
 
 CLA.S.SIF1CAT10N or the OciLAR FixDi ok Birds ' 112 
 The ().iTL.4R FuNDia or Birds in its Kelation to 
 
 A Cla.-SSFICATION of AvES .14 
 
 The Relations ok Reptilian to Avian Findi uq 
 
 Colored Drawings of the Fundus Ocuu of Birds 119 
 
 Colored Drawings of the Fundus Oculi of Reptiles 178 
 
Chapter I 
 INTRODUCTION 
 
 Althouoh the ophthalmoscopic and naked- 
 eye appearances of the fundus ocuii liave been 
 thoroughly described and depicte<l by other 
 writers in many of the Mainniiils — espe- 
 cially in Man —yet very little attention has 
 been paid to the remarkable and interesting 
 eyegrouuds of the animal that exhibits the 
 highest and most varied types of vision — 
 the Bird. The meagre accounts given by 
 even modern writers of the appearances of 
 the avian fundus are probably due either to 
 their quoting the ill-formed opinions of early 
 observers or to their ignorance of the proper 
 use of the ophthalmoscope; facihty in the 
 employment of this instrument is acquired 
 only after long practice, and it is not to be 
 expected that every zoologist can make his 
 own notes of fundus pictures. 
 
 The main purpose of this study is to furnish 
 such a description of the intraocular appear- 
 ances and the methods employed in viewing 
 them as will enable other ophthalmologists 
 and zoologists to further this study by ex- 
 amining the eyegrounds of Birds that come 
 under their observation. 
 
 The eyes of some representative of (prac- 
 tically) all the Orders of Birds and most of 
 their backgrounds have been examined by 
 the writer; and are more or less fully de- 
 scribed and illustrated in this Atlas. More- 
 over, some of the more important species 
 were examined not only ophthalnioscopically 
 before death but macroscopically afterwards. 
 In addition to these methods of investigation 
 extensive microscopic examinations of the 
 tissues were carried on, especially in conjunc- 
 tion with Professor J. R. Slonaker. 
 
 That this research might have a broader and 
 more useful application the writer has also ex- 
 
 l«] 
 
 amined the ocular fundi of a number of species 
 of other vertebrate orders. A brief compari- 
 son will be made between a few of these find- 
 ings and those discovered in the avian fundi. 
 The writer is much indebted to many 
 colleagues and other friends for assistance 
 in carrying out the present investigations, 
 which he began more than ten years ago. 
 Among these are the officials of the London 
 Zoological Society, Mr. Chas. H. Hicks in 
 particular; Professors James R. Slonaker and 
 Frank W. Weymouth of Stanford University; 
 Mr. C. \V. Beebe, of the New York Zoloogical 
 Park; Mr. Cy de Vry of Lincoln Park, Chi- 
 cago, and the officers of the Golden date Park, 
 San Francisco, California; and Mr. Arthur 
 W. Head (the well-known artist) who has so 
 ably depicted and reproduced in this work 
 the avian fundi therein described. His thanks 
 are also due to Mr. C. H. Kennedy, now of 
 Cornell University, who has drawn so faith- 
 fully most of the black and white figures in 
 Chapter VH, illustrating the macroscopic 
 findings of preserved specimens. He is also 
 under obligations to Mr. Douglas Fyfe, who 
 nuide for him a collection of birds' heads in 
 the United States of Colombia; to Lieut.-Col. 
 J. W. Barrett of Melbourne, who performed 
 the same service in Australasia, and to a num- 
 ber of Californians, among them Messrs. Van 
 Rossem, Wright M. Pierce, R. H. Beck, 
 Lieut. Casey Hayes (U. S. Army)and the 
 Managers of the Cawston Ostrich Farm and 
 Bentley Ostrich Farm, who furnished him 
 with abundant material from the Pacific 
 Coast. He also owes his thanks to Professor 
 J. Grinnell for the loan of material from the 
 Museum of Vertebrate Zoology of the Uni- 
 versity of California; to Dr. T. A. Woodruff 
 
6 
 
 THE FUNDUS OCULI OF BIRDS 
 
 who assisted him in his earlier ophthalmo- 
 scopic studies of Birds, and to Professor Henry 
 B. Ward of the University of Illinois foV 
 assistance in reading the proof slu-ets as thev 
 were passing through the press. 
 
 The systematic classification employed for 
 the purposes of this work is that of Bowdlcr 
 
 Sharpt-s Hand-List of Genera and Species 
 (London. 19(19). except that in mentioning 
 •North American Binls the spwific names on 
 tlie (heck List of the American Ornitho- 
 logical Union (1910) has been used. 
 
 Ca8ey a. Wood. 
 Chicago, 1917. 
 
Chapter II 
 SUMMARY OF CONCLUSIONS 
 
 1. The examination of the eyes of Birds 
 is a study of tlie most ad'anced and most 
 varied apparatus for the highest expression 
 of vision known to any vertebrate class. 
 
 i. The examination of the interior of the 
 avian eye through the pupil of animate species 
 (ophthalmoscopy) gives valuable information 
 regarding the function of sight in general and 
 of the eyesight of Birds in particular. 
 
 3. The fundus oculi, or background of the 
 eye, is plainly seen in its normal relations 
 when \iewed during the life of the species, 
 and in many respects this form of exploration 
 is superior to methods carried out on prepared 
 or preserved eyeballs. 
 
 4. The parts and organs visible by the 
 ophthalmoscope in the eye of the Bird are in 
 particular (a) the concavity or general chorio- 
 retinal surface of the posterior half of the 
 eye; (fc) the ijecten; (c) the optic nerve en- 
 trance; (rf) the areas of acute vision; (e) the 
 fundal bloodvessels; (J) opaque nerve fibres. 
 
 a. The appearances of these organs and 
 tissues furnish entirely different, colored fun- 
 dus pictures, and it is frequently possible to 
 recognize a species by viewing its fundus 
 oculi. 
 
 <>. The fundus oculi of Birds exhibits a 
 great variety of areas of distinct vision, and 
 the.se correspond closely to the habits and 
 habitat of these animals — especially their 
 methods of obtaining food, of escape from 
 enemies, of migration, of reproduction, etc. 
 
 7. In spite of recent advances in that di- 
 rection, attempts to reproduce the colored 
 (ophthalmoscopic) appearances of the fundus 
 by photography have so far failed. 
 
 8. The macroscopic appearances of the 
 ocular fundus resulting from an examination 
 of preserved .specimens have a value in this 
 research all their own; for certain forms of 
 examination it is inferior to ophthalmoscopy, 
 for others superior; but it gives no indication 
 of the color tones of the background so well 
 shown by the ophthalmoscope. 
 
 9. As in ophthalmoscopy, attempts to re- 
 produce the details of the cyeground of pre- 
 served specimens have so far given unsatis- 
 factory results. 
 
 10. The use of the niiero.scope in examin- 
 ing the avian eye, and especially serial sec- 
 tions of the parts, is occasionally required 
 to settle anatomical questions that neither 
 ophthalmoscopy nor macroscopy can eluci- 
 date. 
 
 11. Domestication or prolonged captivity 
 brings about abnormal changes in the cye- 
 ground of Birds, so that only healthy, wild 
 specimens should !.e utilized in this or a 
 similar research. 
 
 12. As the colored pictures seen in the 
 fundi of healthy wild birds are invariable in 
 species these appearances may well furnish 
 data for a classification of Aves ranking in 
 importance with other taxonomic indications. 
 
 13. Ophthalmoscopy throws light on the 
 origin of Birds, or at least on their relation 
 to that Sauropsidian ancestry which they 
 hold in common with Reptilia. 
 
 14. In future no report upon a particular 
 avian species can be held complete that 
 ignores the visual apparatus, and especially 
 the appearances of the fundus oculi as shown 
 by the ophthalmoscope. 
 
 [7] 
 
Chapter III 
 
 .^pocios have been examined by the writer 
 ophthalmoscopicallv and otherwise L^ur 
 
 ma.v be the conditions found in the fundi of 
 such b.rds (especially of living biJds) as are 
 most hkely to be useful in a study of com 
 parative ophthalmology. To this end h 
 has confined his atteSion to nLfJu 
 
 Zl7lt 'r ^'"'r^'^ avoidTdleTt^ 
 cated domestic or otherwise abnormal birds, 
 it IS ... thcie more or less tame species that 
 numerous variations from the no^al ey^ 
 
 possTbtr d7= -nsequently it is quitel- 
 possible to deduce from fundus examinat: , 
 of tame or diseased birds any phylwi^^ 
 conclusions worthy the name Th cE 
 
 animals t"'tr ''^ ''^ *"''■ ^-^ticat^J 
 ea ,W to ^' "?* "^'^'^^^ ^^d the 
 
 ;i:;i:Ju^-d=L;:f:Ss::^ 
 
 numerous as to render it impraSbef " 
 any one. even m a long lifetime, to make a 
 complete mvestigation of the c^ular Sack! 
 
 f-ven in an examination of the eves nt h;„i 
 
 always preferable to birds that hive bin 
 Jong confined and exposed to the unwonSS 
 surroundings of cage life. """wonted 
 
 In addition to such wild birds as are acces 
 s.ble in private collections or that ZZt 
 
 18] 
 
 found in every zoological garden or park 
 
 he field naturalist may himself, or by proxy 
 
 trap or she. t the specimens he ileeds."^ E 
 
 ployed by Mu.seums and Colleges, either as 
 duplicates or in conjunction with the cot 
 lectors' other work. The writer, armed w' th 
 
 trips of this kind and has in this way been 
 able to examine the fundi of many disabled 
 or recently killed birds. aisabled 
 
 3of anH'"'7'°°"' ophthalmoscope (see page 
 30) and a large opaque, black umbrella are 
 the most useful implements for field woX 
 A ew minutes before and after the death 
 of the specimen one finds the pupil wide v 
 dilated, so that the ocular interior clnt 
 readily exp ored. Birds that are un^ur^ 
 or merely "winged" are placed in a box !r 
 cage and carried to the laboratory or dark 
 room, here to be examined ophthaJmo 
 scopically at greater leisure. See cLpS V? 
 for macroscopic studies of the fundus in 
 prepared material the bird's head shodd 
 
 Pereti' -a P''""'^ fl"'d- preferably 
 lerenyis-a few minutes after death. I„ 
 
 1. When possible, secure at least three 
 heads of each species. 2. Immediately afS 
 death incise the skin about the nelrwel 
 
 from the head by pulling it forward, wrong 
 side out, over the head, cutting the thin mem 
 branes about the eyes (at the margin oTt^e 
 
 S ; orT"' '"^■"•!; ''^ ^^^ ^^^»'«''- " he 
 ejes or their appendages are cut or injured 
 
 m any way the specimen is render^ iseS 
 
COLLECTION, SELECTION AND PREPARATION OF MATERIAL 
 
 Diseased or i.:jured eyes are also of no use in 
 this investigation. 3. After skinning, sever 
 the head from the body by decapitation close 
 to the base of the skull. 4. Label the head 
 by tying a string — to which a label is at- 
 tached — securely through the nostrils on 
 the beak. This label should bear, written 
 distinctly mth a hard pencil, both the eommon 
 and zoological name of the bird, the date and 
 locality of collection, as well as the name and 
 address of the collector. Heads of the same 
 species should be numbered serially (1, 2, 3, 
 etc.). 5. The foregoing operations should 
 occupy as brief a time as possible. The head 
 should then be immersed in a quantity of 
 fresh I'lrenyi's fluid equal to twenty times 
 the volume of the head. Fruit jars are con- 
 venient containers for this purpose. For- 
 mida of Perenyi's Fluid: 10% nitric acid in 
 clean wate/ (10 acid to 90 water), 4 parts; 
 95% (commercial grain) alcohol, 3 parts; 
 0.5% chromic acid in clean water (grni. 0.50 
 acid to 100 cc. water, 3 parts. After a few 
 minutes this mixture turns a violet color. 
 It may be kept in bulk indefinitely if well 
 corked. 6. Leave the heads in Perenyi's 
 fluid until the hardest bones of the skull be- 
 come soft and pliahS when touched with a 
 scalpel. The time required will depend upon 
 the size of the head. The following periods 
 of immersion will usually be suflicient: Small 
 heads, as sparrow, robin, etc., 24 hours; me- 
 dium sized heads, as the crow, 36 hours; large 
 heads, as the owl, 48 hours; extra large heads, 
 as the ostrich, 3 to 4 days. 7. After decal- 
 cification in Perenyi's fluid the heads should 
 be treated with the following percentages of 
 commercial grain alcohol. In each case use 
 approximately 20 volumes of the alcohol 
 solution to one volume of the head. The best 
 results are obtained by using fresh alcohol solu- 
 tion for each head. Leave the heads in each 
 of these alcohols for the same period they were 
 immersed in Perenyi's fluid. 70% alcohol is 
 made by .nixing 70 volumes of 95% (commer- 
 cial grain) alcohol with 25 volumes of clean 
 water; 80% alcohol, made by mixmg 80 vol- 
 umes of 95% alcohol with 15 volumes of clean 
 water; 95% (commercial grain) alcohol. 8. 
 After treatment with the last alcohol solution 
 
 the heads may be packed in a fruit jar suflS- 
 ciently large to hold them, covered with 95% 
 alcohol and carefully sealed to prevent leakage. 
 Should the eyeball lose its rotundity, or 
 "cave in" anywhere, the defect may be some- 
 times remedied by injecting 70% alcohol, by 
 means of a hypodermic syringe, into the 
 vitreous chamber. 
 
 Prepared in this way the bones of the skull 
 and the sclerotic plates are so softened that 
 sections of them can readily be made, while 
 the walls of the eyeball are so hardened that 
 they can be bisected at the equator with a sharp 
 razor and the anterior segment removed, with 
 the cornea, lens and vitreous. The parts 
 behind, in the posterior half of the globe, 
 constituting the fundus oculi, eyeground or 
 background of the eye, remain in situ and can 
 be readily examined. 
 
 Although injection of the arteries of the 
 avian fundus is not as useful as in those eyes 
 in which there are retinal vessels, yet occa- 
 sionally the choroidal bloodvessels and (per- 
 haps) the pecten are affected by it and thus 
 rendered more visible. In that case prefer- 
 ably the gelatine-carmine mass of Ranvier is 
 injected by way of the carotid arteries. 
 
 In examining macroscopically the posterior 
 segment of the eyeball a magnifying lens of 
 10 cm. focus may sometimes be used but the 
 unaided eye is generally satisfactory. 
 
 On removing the hardened vitreous (by 
 means of a mounted needle) the grayish, 
 translucent retina should lie smoothly on the 
 choroid when the preparation is a success. 
 Retinal wrinkling occurs not infrequently in 
 some part of the eyeground, in which case it 
 may give rise to errors in determining the 
 presence or absence of some of the areas of 
 distinct vision, etc. A well preserved eyeball 
 furnishes satisfactory material for man" vears. 
 For microscopic sections a window it in 
 the globe in the plane of the desire. .ons, 
 
 the vitreous removed without injury .o the 
 choroid and retina and the cavity filled (by 
 immersion) with celloidin. However, as the 
 minutiae of this form of investigation is out- 
 side the scope of this work the writer must 
 refer the reader to laboratory textbooks on 
 the subject. 
 
10 
 
 THE FUNDUS OCULI OF BIRDS 
 
 BIBLIOGRAPHY 
 
 In Hildition to tin- wi-ll-known niunuttl.s on 
 ornilholoRV, ophthalmology and hiology thf 
 writer has had most liclp in tliis investigation 
 from the following: 
 
 AiiF.LHDORKF, (J., UIxT diLs Wrlidlti'ii ilcs I'ektpti.t Iwi 
 dcr Akkointiiodation ilcs N'ogelnugps. Archir f. 
 Vtrgleichende Ophthalmoliigie, 1 Jahrfjang, III Heft, 
 No. 3. pp. •ilKt-'iOi, !!»I(t. 
 
 Auelsdorff-Wehset.v.. \'>'rxlfi<ln'ncl pliysioloKisclii- 
 L'ntersucliiinK (IIht clni Kliissigki'lts-Wtilisel ilivt 
 AiiRcs (lor WirU'llhuTTcilir. l". Tlii-il, Viigel, 
 Archil fiir Aiigenheilkiinile. \ol. 04. pp. (!j-Hl, l!»0!». 
 
 AiDiDo.N, J. J., UrnitlioIngipHi Bibliography, \'ol. i, 
 pp. 33 47, 1S3.). 
 
 B.^VEK, Jos., Hilillicho Dar.stilliiri); ili's Be.sundcn und 
 krankcn AiiKos nn.sorcr Ilaiistliicrc, Wicii, \HiH. 
 
 Bk.m iiE<;.vKDE, M., Note .siir ^etudl■.)plltalnlo.s(•(lpil|lU• 
 d^ I'fiKiie de I'i .-il des Oiseaux, ('nmpt. Itfiiil. el 
 Mfm. Soe. de Biologie, Paris .sor., T. i, pp. 13-i-136, 
 1873. 
 
 Bedd.\kd, Frank E., The Structure and Classification 
 of Birds, London, 1898. 
 
 Beebe, C. Wilmam, Bird Portraits. Birds and Sature 
 Magazine, Vol. 1, No. I, p. U, Ma.\-, im)7. 
 
 Beer, Tiieodor. Studien Ulwr die .Vkkoinniodalion dc.s 
 VoKclanfjes, I'fliiger'a Archir, LIU, pp. 17o-i37, 
 1893. 
 
 Beux;c'«v, ,I., Zur Entwickelunt! dcr Kopfnervn der 
 Viinel. Bull. .Siic Satural, Moscoii, n. 177, 19ort. 
 
 Bernu, .\i)(»i,f Ilfiio, Die En'wicklur.;,' des Pe<ten ini 
 Auge des lluhnchens au.s dci. Bliiltern dcr .\ugen- 
 lilase. Inaugural-Oi.ssertation, Bonn, lUOj. 
 
 Bhiecke, E., ri>er den Musculus ('raniptonianu.s und 
 liber den Spannmuskel dcr Cho.-oidca, Mueller's 
 Archil}. Anal. u. I'hys., p. 370, ISW. 
 
 Bri Hix, Th. A., Die Iris der Vogcl insl)csonderc der 
 Rauh, Siirapf und Hl.winim Viigcl der deutschen 
 Fauna, a!s unterschicdcncs Mcrkrnal der Arten, des 
 AlLers und Geschlechts, /.ml. (iarten, p. i9(\, 1870. 
 
 CA.MERON, JcjiiN, On the development of the layers of 
 the retina in the chick after the formation of the 
 optic cup, Proc. Rmjal Hoc. u} hmdiin. Vol. 70, 
 p. 84-8B, IflOi. 
 
 Ca-nfield, William B., Vergleichcnde anatoinische 
 Studien liber den Accomniodationsapparat des 
 Vogelauges, Arch. mikr. A'lat., Vol. i8, p. 1^1-70, 
 1880. 
 
 Carpenter, F. \V., Tlie Ciliary Ganglion of Birds, 
 Folia Seuro-Binlogica. Vol. j, p. 738, 1911. 
 
 Chievitz, tt>er das Vorkominen der Area ceiitrahs 
 retinee in den vier hUheren Wirbeltierklassen, Archie 
 fiir Anal, und Physinl. Anal., pp. 311-334, 1891. 
 
 Cole, Leon J., Have all Eyes the Power of Forming 
 Images.' American Academy of Arts and Hciences, 
 Vol. 42. No. 18, January, 1807. 
 
 CoLUN, R., Premiers Etudes du d^veloppeinent du 
 
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 L'ntcrsuchungen llln-r die verglcichende Anatomic 
 
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 Carnegie Institution of iVashington, 190!). 
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 Ivcipzig, 1907. 
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 1888. 
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 1908. 
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 Arch.f. Ophlhalm., Vol. 4,3, pt. 3, p. 409. 1898. 
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 1914. 
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COLLECTION, SELECTION AND PREPARATION OF MATERIAL 
 
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 1893. 
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 iifli 
 
 ii!i 
 
 'It! 
 
Chapter iv 
 
 A REVIEW OF THE ANATOMY AND PHYSIOLOC V op Tur- 
 ORGANS AND TISSUES SEEN In'^THE fS^^^ ^""^ 
 OCULI OF THE BIRD 
 
 A COMPARISON of the ocular structure., in the 
 vertebrate sub-classes shows that the jmsterior 
 two-th.r,ls of the eyeball contai.. practically 
 the same organs in all, with, of course, numer- 
 ous modifications of them to suit the visual 
 requirements of a particular species 
 
 In Vertebrates generally the fundus organs 
 of especm interest are the retinal and chormdal 
 bloodvesseh (in some instances p- ejected into 
 the rt/r^o«* humor), the choroid, the retina 
 and the optic nerve entrance, the last named 
 otherwise known as the optic di.c, poms 
 opticus, nerve-head or papilla. 
 
 Although the ret ,«l layers are generally 
 transparent, an.l not visible during life, vet 
 this IS not true of all species; e.g., occasionally 
 n certain number of translucent nerve-fibre 
 sheaths (neurilemmata) are prolonge.1 into 
 ttie retina and variously distributed over the 
 background .,f the eye. and, by „,ean.s of (h.- 
 ophthalmoscope especially, are visible and 
 have been described under the name medul- 
 lated or opaque" nerve fibres. 
 
 These organs ano tissues will be considered 
 in their order. 
 
 Fig. 1 
 
 English Sparrow. A, area centralis; F. fovea- O onH. 
 
 ^erjinr /' r*-^ Thep^.rrdsVnfo 
 vertical in this 6gure. (Wood and Slonaker.) 
 
 fl«) 
 
ANATOMY OF THE FUNDUS ORGANS IN BIRDS 
 
 IS 
 
 J 
 
 tT 
 
 rill 
 
 PI 
 
 il3 
 
 Jl 
 
 ^ o 
 
 1.1 s 
 
 Z ,-3 
 
 u5 
 
 I 
 
14 
 
 THE Fl'NDUS OCULI OF BIRDS 
 
 Fig. 4 
 
 The Temporal Mononucular Fundus of the Great 
 Homed Owl — Buio tirginianut. (After Slonaker.) 
 FT, visual axis of the single, temporal fovea; P, pecten. 
 
ANATOMY OF THE FUNDUS OPGANS IN BIRDS 
 
 M 
 
 83^11 
 
 isS- 
 
 *• 
 
Ifl 
 
 TIIK FlNins (Mil,! (»F BIHDS 
 
 The Avian Choroid 
 
 The i-lniriiHl •■•'ill nhiirniiliti) nf HinU' cyci 
 '\* iilwiivi viTV tliiti, v\»-H ill liirKi- ••\«l>iilU, 
 lull lliickiT tlmii ill I In- >. •iiiiiiir'. i-.Vf. 'rill- 
 viiwiiliir, i;i|<ill.irv iiii''<ln's {rlutriiM-iipillnrin) 
 iiri' ;>f imviiliir ^i/i' ami mIIi^t nitmiw; in 
 Siriilliiii III)- I 'i|iilliirii'H iiri' 0.01 0.0{ miii. 
 wiili' liriiiiiti'r lliiiii in iitlu'r liinU. TIm- 
 spiitr^ iK'lwn'ii th<' •■iijiilliirif^ iirt', lu'cfiriliiiij 
 
 i-t MM-n III it* wiiii-il iiIkimI IIm' liiiK- ••f liiii^-li- 
 iiiK (wlii'ii ilitfi'D'Hliiiliiiri lakes plan' iiio^l 
 iM'liM-Iyi aiul lii'ciiiiii"* lliiiiiuT anil ri'iiiaiii'< 
 |NTiiiiiiifiil hIii-ii llif liini i-i M-vcral iiiniillii 
 •>l<l. 
 
 A lajHlinn it aliM III in I' nU, alth<iii);li Ihc 
 Niiltiati (Ktri^'li liii-< 11 ){lii'''<-lik^' la.MT in th<' 
 I'liiiroiil, of laiiii'llali'il '■tniilliri', inpalili- of 
 rrlli-ctiiig littlit ooi! priMliicing rulur inh r- 
 
 FiR. 7 
 MucroiM'opiiHl, I'iKtiiiortiMii Diai(r»ni nf llii- liiruliililiiiiuiilnr Fiiiiilii'i ami Orliil nf ll»' Titii iSlmia liinindo). 
 ;', optic iicrvo rntnimt'; I', [Hftcii; Ft. fnvcii uiiil iiri'B li'm|i<>ruli'<; Fii, fovea ami area iia»uli«^ Ali, liaiicl-liki' 
 
 area. (After SlonakiT.) 
 
 lo Franz, coniplclcly frf- of cells and pigment. 
 The aiMiiunt of piKiiK-nt in lli<> >.-xtcrnal layer 
 is sulijcct tit viiriati'm. 
 
 The thickness of this roat i Panner dommti- 
 rim is alxnit •iiW microns. The re.turls of 
 the choriiH'apiihiris measure iroiii 10 to '20 
 micriiii. in widtii; lu'tween I hem is a finely 
 punctate s ilistniice. Thi> laver is 7 to 8 
 iniirons thick. Kxternally Ih. re is an endo- 
 thelial layer, then a ret work of tine elastic 
 tihres without cells or pigment; finally, a 
 dense plexus of connecting! cell- 
 
 Thc mnrs run within the <ii|>rachoroi<lal 
 space and send only fine filaments into trahec- 
 ulie that form a cavernous system throughout 
 the whole coat. 
 
 ^■lonaker found the choroid (o be enlarged 
 ami most vascular (see Fig. 1. just opposite 
 the fovea, esjK'cially in embryonal life <oid 
 in newly-hatched indi\'iiliials. It is in the 
 fonner instance > ne uf th'- indications of the 
 spot where the fovea will eventually form; 
 then it widens during the foveal formation, 
 
 fereiK'c etfecN. This arrangement, howext-r, 
 is only a retino-choroidal variation, and not a 
 true ta|H'tuin. 
 
 The Retina of Birds 
 
 Tlie aculeness of the eyesight in Hirds i> 
 largely ilue to the fineness anil close arrange- 
 ment of Ihc retinal elements. .S-e Fig. !>. 
 
 (Justav Fritscli (Arrhlr, \likritxk(:p. Aniil- 
 omie. Vol. 7«, p. 'iio, lilll) DelievcN that true 
 rods and cones are found in Birds, just a-< 
 tli(>y are in Mammals, and they should lie 
 design! 'cd as such. In Ihc region of the 
 fovea riiitniUn there is also a dwarfed, cone- 
 like form. The rolond, riiiiiiil (Iniphl.s of 
 Birds apiK'ar mostly in the rod elements, 
 although they are sometimes seen in conjunc- 
 tion with cones. .Vmoi. r the ceii'tal cones is 
 also found, quite commonly, a body which is 
 colored brown by osmic iK-id. 
 
 .\ceording to Franz (I ^ VmnUirni' li)H ) 
 the layers of the avian n! uia are more sharply 
 defined than in any other vertebrate; even 
 
ANATOMY OF THE FrNDI.S OfUi.WS I\ nniDS 
 
 niorv ito thnn in Miininmiv Tlu-n- urt- ni> 
 M^pHrntc lii|H>ltir or opticiil Kmixliori c-lN jn 
 BiriN, while we flmi in Miinimnlt i'«>liii<,i 
 iinmcrinc n-IN, and, in n-plili".. lii|K)lii' ..lU. 
 All liirilt iMWMi'*, hmN ii< well .iM villus. 
 iillli<iiit(h in v<T,v iliffrn-nl iirriint{< nuiiN. 
 11. Mllllcr crroiu'iiiivly ijcpiiiiil ihi< tnuvt of 
 the I'imim with loiitf rjlinilrinil i-xln-niilie*. 
 
 tk>^-i''.K'M 
 
 mm 
 
 Fifjs. 8, and 10 
 
 The Retina of VarlDiiH V(rt<'l)riiti'i 
 
 Fig. 8, Liiard; Fi«. », Bird (Common Crowi; Vig. 10, Mummal 
 
 (I)oK). xilO. (After I'. Chiarini.) 
 
 when thfsf rtally IwIohk to tin- rods. The 
 • I IK'S have each a single oil droplet, whose 
 eolor varies. Cajnl tins ditFereiitiiited (in 
 Birds and in Reptiles) "slniiKht" and 
 "obli(iue" eones. 
 
 The noelei of the cones usually lie inside 
 the iiiembraua limitann ixtcnia of the retina. 
 .Several "oblique" cones have an enlarge- 
 ment of the en<l inside the inner layer of 
 nuclei. The "twin" coim-s, whose nuclei are 
 not to he seen, lie near the incmhrana limitann; 
 the smaller nucleus of the pair is in a facet of 
 the larger. The rod nuclei are usually found 
 in the internal half of the nuclear layer. Their 
 small end branches in the outer reiicular 
 
 layer, stniehing out farther than the iiid ..f 
 the I'one. The r<Hl ill niM'tiirnal bird-, .n,!, 
 
 "» •! xteriiiil portion nf the cnlrr retirulur 
 
 lii.\er with a niMh.-ily a little ball ill thf 
 end without any bratiihes. 
 
 • ajal ditfenntiales threo »u[).rinipo« d 
 plexuses in the eilenial riiinal lin/ir; I hi' (ir-.|, 
 eoniiHwil of the basal fibrils of the rod.; 
 the second, the en l-lhr.ad- of Ihr 
 Kiraighl (■one^; the third, (ibriN 
 which eiiianali- from the oblit|M<' 
 cones, that i- -ry cell coine in 
 eonlad with Itn dendrites of i er- 
 tain bi|M>lars and loiij^iiiidinal gim- 
 glion celU, 
 
 .Fust as in lieptiles, Siliirtrir- 
 deeker found in the Cliiekeii, (row 
 and (Joose, in (he cvleniid n-liruhir 
 iiMi tear layer, eoiicenl ric »upporl iii>; 
 cells without nuclei. 
 
 Tllf iniiir iincliar lai/ir nf Ihr ri- 
 tina. One finds on the extreme 
 out<T as|«'<t horizontal KanKlinri 
 cellsand I.)) bru-h-lik<-cell>nf < jijid, 
 with many projections iiml a long 
 horizontal cyliniler which, like the 
 short projections, tiends around the 
 outer reticularis and ends Iherr 
 with an enlargement and lir.iiicli<s; 
 (l> star-like cells with soniewhat 
 longer dendrites and a short c\ lin- 
 der ieh first turns in and then 
 ou!. Hetween. and further in than 
 the cells, which Schiefrerdecker calls 
 -.ucleatetl cells, arc found two kinds 
 of bipolars; first, outer bipolars with highly 
 developed dendrites, and internal, small or 
 thin bipolars with weaker dendrites. The 
 thick bipolars .seem to branch out in the fifth 
 layer of the internal reticularis; the thin 
 bipolars assume more the form of a layer in 
 the inner reticularis. 
 
 •Vs in all animals, the nuclei of the sup- 
 porting fibres of Mailer in the avian retina 
 are situated in the internal nuclear layer. 
 
 In the inner portion of the internal nuclear 
 layer are found, as ganglion cells, the layer 
 of amacrine cells, which are divided, both in 
 Birds and Biptilia, into (1) nervous and 
 (i) proper amacrine cells. 
 
18 
 
 The layer of gangUnn rells. Cajal differ- 
 ent iatos tk- following ...pes of ganglion 
 optical eolls: («) single-layere.l cells, sprea.l- 
 ing out over the internal reticular laver 
 partly nniltipolar, but mostly l.elonging t(i 
 the reticularis; {b) many-layered, mulliiwlar 
 cells. The smallest are plentiful in the 
 I asserifornies; i.e., the .Sparrow, Chadinch, 
 vireenfineh, etc. 
 
 It should be noticed that Dogiel e\pres.sed 
 the opinion that those cells which in form, 
 size and character of branching of the pro- 
 toplasmal and cylintlrical processes, belong 
 to a certain characteristic tyin-, anastomose 
 with each other, or form a "colony." 
 
 The relatively thick, optic conmctire tw.wr 
 receives single, dissimilar, thick filaments 
 which, originating centrifugallv from the 
 optic nerve, intermingle with the internal 
 plexiform tissue and end, according to Cajal, 
 on the level of the amacrine cell-layer. 
 
 Specifc difcrences in retinal elements. As 
 in almost all of the sub-cla.sses of vertebrates 
 there are differences in the retinae of Birds' 
 especially in the tissues of the rods and cones.' 
 The numerical proportion of rods to cones 
 in different species is quite marked. Uichest 
 in cones are the diurnal Birds of Prey Cor- 
 responding to these in xNight Owls are "rod- 
 retmae." M. Schultze thinks that while 
 Owls have many long rods, they have few 
 cones; Krause believes that the cones are 
 invisible on ccount of the number and length 
 of the rods, but that they are no less numer- 
 ous in the Owl than in the Falcon. 
 
 (Jeese have, according to Krause, many 
 long rods and stand in that respect mi.lwav 
 between Owls and diurnal Birds of Prey 
 The Flamingo has the longest of all rod ex- 
 tremities. The Heron has manv thick rods 
 Krause seeks to weaken the force of the 
 statement of .Schultze, that Nocturnal Birds 
 are distinguished by the preponderance of 
 cones and a diminished number of rods bv 
 pointing to the discovery of Ileinemann Ih'^' 
 in (the nocturnal) Xycticorax the rods are 
 scarce; that the Swallows. Ilirundo rustiea 
 and Chehdon urbica, in the relative increase 
 of their cones resemble the Owls, while 
 Athena noctua possesses even more cones than 
 
 THE FUNDUS OCULI OF BIRDS 
 
 rods. According to Hess, the number of 
 cones ,n the OwPs retina reaches 1 to i\ ', 
 millions. 
 
 However the teaching of Schultze has much 
 in Its favor; insofar as that the hypothesis 
 supported by it, viz., that ccnes are reallv 
 CO or-pereipient organs (the rods perceiving 
 light and form) finds proof in the fact that 
 rods alone are found only in the retinae of 
 <ieep-sea Fishes and Whales. 
 
 Hegarding the possession of retin, I „// 
 droplets, ellipsoids, paraboloids and hyper- 
 bolo,ds, there are, accor.ling to Krau.se, manv 
 «lilferences in siiecies. In Cardinalis rirgin- 
 umus and Fnngilla spinas, he differentii'itcd 
 two kinds of cones; in the Hen three outer 
 double cones. Fringilla spinns shows a bine 
 oil droplet in many of its double cones. 
 
 The layer of nerve filaments receives in tlu- 
 ligeon and a few other birds partly medul- 
 lated fibres. Franz finds in manv birds that 
 the layer of nerve filaments in 'the vicinitv 
 of the optic foramen corresponds to what ili 
 •Mammals are called "spider cells." 
 
 Pigment Movement in the Retina of Birds 
 Although this strange phenomenon probablv 
 occurs m most vertebrates, and to a slight 
 extent m some invertebrates, yet it is in birds 
 that It IS best studied. As Kalt remarks, the 
 retmal pigmented epithelium forms fringes 
 which, under the influence of light, descend 
 to the external hraiting membrane. In the 
 dark they do not move past (at least in the 
 I igeon) the middle of the rods and cones. 
 
 Th purple of the retina is missing, accord- 
 mg to Kuhno, from the rods ...d cones of the 
 Hen : nd Pi^ron. It exists in large quantities, 
 howe^or, m the external segments of the rods 
 of the Scrwch Owl, while the cones are devoid 
 of it. 
 
 As Kuhne points out, the cones have vari- 
 able dimensions, and are single or double 
 At the end of the internal segment they have 
 a single, oily, colored ball or droplet, which 
 however, is not found in the interior of thJ 
 accessory cones. In a fresh retina the bulls 
 show immediately with their various tints 
 
 As far as the color of the retinal oil-droplet 
 of Birds m general is concerned, Schultze 
 
ANATOMY OF THE FUNDUS ORGANS IN BIRDS 
 
 differentiates mainly (a) colorless, (6) yellow 
 to reddish-yeilow and (c) red droplets. 
 Again, Le finds a difleronce between Day 
 Birds and Owls in that the red are lacking 
 in the latter while the pale yellow and color- 
 less varieties are more plentiful. 
 
 According to Kalt, Waelchli distinguishes 
 four varieties of colored oil drojilets in the 
 avian retina; red halls disseminated over the 
 whole membrane; orange, or yellow balls, 
 whose distribution is the same; greenish- 
 yellow ones seen at the periphery; and un- 
 colored ones spread in small f|uanlities over 
 all. Osmic acid colors all the,e balls black. 
 The coloration is particularly intense in the 
 macular region. 
 
 The locality in which the colored droplets 
 are found varies with each tint. The green 
 balls are situated nearest the external sur- 
 face of the retina, the red come next, then 
 the yellow, and finally the colorless balls. 
 
 A chemical examination of the colored 
 glol)nles in the cones of birds was made by 
 Kuhne. A hundred retinas of the Hen were 
 treated with alcohol and ellier. The fatty 
 material thus dissolved (colored re<l) gave, 
 with soda, a soap from which was extracted 
 by petroleum ether a green coloring matter; 
 iiy sulphuric ether an orange material; by 
 turpentine a deep rose colorant; this last' one 
 is, however, insoluble in sulphide of carbon. 
 Kiihne gave the names of chloroplianc, xanlh- 
 ophaiic and rhodopkane to these pigments. 
 
 The Amt.1 of the Kdina in Birds. Avian 
 areae centrales are of greater variety — espe- 
 cially regions of distinct vision — and in 
 greater number than in other Vertebrata>. 
 
 As described (.see Chapter VH, page 59) and 
 depicted elsewhere (Figs. 110 to 115 inclu- 
 sive) the writer believes that there are at 
 least six forms of these area? in Birds. 
 
 According to Chievilz (1891) and Slonaker 
 (1897) there is at least one round macular 
 region with a fovea in practically all Birds. 
 This single area of monocular vision (see 
 Figs. 110 and 111) is in most Birds situated 
 somewhat centrally, slightly to the temporal 
 or the nasal side. 
 
 In many species, diurnal Birds of Prey for 
 example, besides a central fovea in the nasal 
 
 19 
 
 aspect of the retina, fovea nasalis, there is a 
 fovea temporalis, which with the fovea tempo- 
 ralis of the opposite eye may serve for binocu- 
 lar vision. 
 
 The area centralis retina:, macula liitea or 
 macular region, is found in all classes of 
 Vertebrates and its presence is the rule, espe- 
 cially 111 Reptiles and Birds. 
 
 The terms commonly applied to the various 
 parts of the macular region are as follows: 
 the whole area is designated the macula, or 
 area centralis or "yellow spot;" the more 
 •sensitive, smaller area, generally disposed in 
 the geometrical center of the macula, is called 
 the fovea. Not infrequently there is .seen a 
 still .-mailer point at the bottom of the foveal 
 depression; this is termed ihcfoveola. This is 
 the terminology employed in human ophthal- 
 mology and there seems no good reason why it 
 should not be applied to all vertebrate eves. 
 When the macula is placed on the nasal 
 aspect of tlu! optic entrance it is called the 
 naml macula or area na.«ali.f; on the temporal 
 side, the temporal macula or area temporalis. 
 In the same way, one speaks of the area or 
 fovea na.'iali.f and fovea temporalis. 
 
 The area centralis presents a thick portion 
 of the retina, where the arrangement of the 
 elements recalls that observed at the level 
 of the "yellow spot" of the human retina. 
 There is in this region an increase of gan- 
 glionic cells and of the receiving or percipient 
 elements — the cones and rods. 
 
 The depth of the fovea may be regarded as a 
 mea.sure of the sharpness of vision. Slonaker 
 classifies fovea; as deep, medium and shallow. 
 The round fovea is especially "deeji" in 
 swift Fliers and Birds of Prey; "medium" to 
 "weak" in most other birds, except that it is 
 "shallow" in the domestic Pigeon, and prob- 
 ably lacking in the Hen. 
 
 Krause is probably right in believing that 
 domestication brings about the disappear- 
 ance of the fovea. 
 
 Both fovea' in the bimacular fundi of diur- 
 nal Birds of Prey are structurally much alike, 
 ill that they have in them only cones, and only 
 those with yellow droplets. 
 
 Besides this central area (with a fovea) 
 there is often, in Birds, a ribbon- or band-like 
 
 -.1?; 
 
 I 
 
to 
 
 THE FUNDUS OCULI OF BIRDS 
 
 it ** ,-' 
 
 S — i. 
 
 iji 
 
 9 ~^ 
 
 2 5- 
 
 - J^ = 
 
 ■^ i. ^ ^ 
 "a ^^ i 
 
 "go. 
 
 -Sue 
 -' ^ - 
 
 •s _!'• 2 
 
 s I- I 
 
 w fc. > 
 
 
 
 ■o 
 s 
 
 
 .-§ b 
 
 
 ■i-i-g 
 
 
 peg 
 
 
 o S^ 
 
 
 t- .= 3 
 
 
 i i i 
 
 
 *^ =»» E 
 
 
 
 
 SO e 
 
 
 S. -a ii 
 
 
 i £ j; 
 
 
 ~t*""l 
 
 
 sl i:3 
 
 
 
 
 fe *o - 55 
 
 
 5?.M 
 
 
 ^fi 
 
 
 ^^■:7. 
 
 >^h'j^A"-'fi^ 
 
ANATOMY OF THE FUNDUS ORGANS IN BIRDS 
 
 arrdngement of retinal lismie tliat is ffcnerally 
 foiiiul ill the horizoiiliil inoridiiiii. It is mostly 
 soi-ii ill tiiosc l)ir(ls that seek Ihcir food ujmn 
 the ground, c.k.. Moto.iNa. Saxicoia, Stnithio, 
 Totamis. Triii«a, Lams, Squatarola; also 
 III Iho (ioosc, Mainiiigo and otlier A(|uatic 
 Itirds. Sec, for example. Figure 11. 
 
 Perhaps tJie retina manifests the greatest 
 foveal development in swift-flyiiiK Iiirrls. For 
 example, Cypselas, Ilirundo and Sterna have 
 three fovea'. 
 
 Sioiiaker has also noticed an important 
 variation in the relative position of avian 
 fovea' and has offered an explanation home 
 out l)y the resnits of this investigation; the 
 fovea nasalis is almost invariably found in 
 the same fundus area, Imt the locality of the 
 toniTioral fovea de|)ends upon the position of 
 the e in the head. As the eyes arc turned 
 more and more forward the fovea temporalis 
 approaches the fovea na.salis. As binocular 
 vision become.s more frecjuent both foveie 
 may become merged into one, generally 
 deeper, i)it. There is also a corresponding 
 change to an asymmetrical form of the eye- 
 ball and to a peculiar position of the crystal- 
 line lens in birds with binocular vision. 
 
 In many such birds, the White-bellied 
 Swallow (see Fig. ii) and the various Terns 
 for example, the nasal fovea is deep and sharp, 
 while the temporal fovea is quite shallow and 
 the eyes are almost symmetrical: but in birds 
 with more marked binocular vision. Hawks, 
 for example, the temiioral fovea has the 
 greater depth an<l the eye becomes more asyni- 
 melrical. Tlu' climax is reached in Owls, 
 whose eyes are most irregular in form, who 
 have but one (deep) temi)oral macula and 
 who se<' only binoeularly. 
 
 .Vs with other organs in their body the com- 
 |)oncnl parts of the visual apparatus of Birds 
 arc arranged and adjusted mainly to enable 
 the Bird lo obtain food ancl to escape his 
 hereditary enemies. In a minor degree, too, 
 we observe the inlluence of the necessity for 
 swift locomotion. Otlier (occasional) taxo- 
 noinic influences are apparent in certain special 
 visual rerinirements, such as nocturnal vision, 
 the use of the eyes under wi.ter, the employ- 
 ment of the eyes for vision both in air and 
 
 21 
 
 water, the visualization of minute objects 
 close at hand, etc. This statement is true 
 in full measiin- of the organs and tissues com- 
 prising the fundus oculi. 
 
 Stereoscopic, binocular, single vision in 
 Birds with double foveie — and this is the 
 most acut<, accurate and effective form of 
 eyesight that these or any other animals 
 know — is probably accomplished by the two 
 temporal foveie acting in cerebral uni.son. 
 It is this form of sight, for example, that 
 enables the Osprey and other Hawks first to 
 locate from a distance and then to dart 
 unerringly upon their prey. 
 
 The deep and evidently more acutely func- 
 tionating nasal fovea is. in the writer's opin- 
 ion, employed for monocular vision only, 
 and there seems every reason to believe that 
 Birds with double fovea? have exceptionally 
 good eyesight with each eye .se|)arately; they 
 are, liy this effective combination, enabled 
 not only to command a view of the highest 
 efhciency over the whole horizon, but also have 
 the power to concentrate it when needed upon 
 particular objects invisible or indistinctly 
 visible to other species not so provided. 
 
 It must, however, be acknowledged that 
 the neurology of Birds, involved in these 
 questions, is a sub-.seetion of biology as yet 
 in its infancy; only when the histology, 
 pathology and experimental physiology- of the 
 avian cerebrd organs and their connections 
 have been w. :ed out as they have been in 
 Man sliall we know how the paths pursued 
 by "brain eurrents" involved in this switch- 
 ing from monocular single vision to binocular 
 siglit run and are controlled. As these ques- 
 tions now stand the om,, certain thing that 
 can be said is that, with the po.ssible exception 
 of the Owls, they must be totally unlike the 
 cerebral and spinal arrangements discovered 
 in Man and the higher Apes. 
 
 Of the irfiysiologj- and psychology involved 
 in the ribbon- or band-like area we know still 
 less. In all probability it is a device to enable 
 swift-flying birds to take their prey on the 
 wing, and other species to find their food on the 
 ground while they themselves also stand on 
 terra firma; in other words, birds with banded 
 retinae possess eyes that are chieflj- employed 
 
 T^WM^ 
 
22 
 
 THE FUNDUS OCULI OF BIRDS 
 
 in food-searching in such u fashion that ♦hey 
 are enal.le.l to see one object very distinctly 
 iiNd neighboring objects (in a restricted field 
 of vision) more distinctly than is permitted 
 l>y the comparatively insensitive retina of 
 the roniaininj; fundal areas. 
 
 IiifulaiHiiullary angle. The relations, es- 
 JKcially of fundal position, between the optic 
 nerve entrance, the pecten, and the areas of 
 distmct vision are, as we have nireadv seen, 
 of some biological importance. I'pon the 
 locality of the macular regions depend, in 
 great measure, the qualify and precision of 
 the eyesight o. each particular bird. That 
 one may facilitate references to the location 
 in the eyegrou'id of the retinal band the writer 
 proposes to measure what he has lerme.l the 
 nifulapapillary angle {in/ula, a band, papilla, 
 the optic <lisc), made by the junction of the 
 major axis of the ovoid eiitrnnte of the optic 
 nerve prolonged until it meets the retinal 
 band on the nasal side of the point of contact. 
 In the case of the Hudsonian Curlew (see 
 Fig. 125) it is 50°. 
 
 The Optic Nerve of Birds 
 In all Vertebrates the oi)tic nerve has the 
 form of a cord, sometimes very short, as in 
 Birds, and occasionally long, as in Man. 
 which extends from the optic foramen to the 
 posterior segment of the eyeball, where its 
 expansion forms the retina. 
 
 In Birds, whose ocular movements displace 
 the eyeball very little, the nerve takes the 
 form of a short, almost rectilinear cord; while 
 in animals with mobile eyes, such as the large 
 Mamnufers, the nerve is long, round and 
 b-sha{)ed, to follow the displacements of the 
 posterior hemisphere without pulling or drag- 
 ging. Its diameter greatly varies; it may 
 reach 8 mm., as in the Whale. The rule is 
 that it roughly corresponds in size and length 
 to the volume of the eye-ball. 
 
 As Kalt says, the pia mater forms the 
 neurilemma or sheath of the optic nerve. 
 Ihe multiple partitions which it sends into 
 Its substance, divide the nerve into bundles; 
 tlie dissepiments anastomose with each other' 
 Tins is the type well known among Mammals. 
 Birds exhibit one peculiarity; at the inner 
 
 aspect of the nerve the pial partitions pene- 
 trate perpendicularly into the substance of 
 the nerve and do not ana.stoniose until they 
 reach about half way into the thickness o'f 
 the cord. Analogous jK-rpendicular parti- 
 tions, but very short, exist .sometimes on the 
 external side. The result is that the nerve 
 has a foliated appearance, especially marked 
 on the internal side. 
 
 The Pecten, Marsupium, Fan or Comb 
 
 of Birds 
 By means of the ophthalino.seope and direct 
 illumination there is seen, below and exter- 
 nally, in the fundus of every bird, a black 
 mass of variable form. When the free edge 
 of this organ is illuminated one notices a 
 longitudinal strip with undulating e.'ges. 
 If one throws the light upon the base of this 
 object — the pecten or comb — the papilla 
 looks like a sparkling white area whose mar- 
 gins are ed<red with black, the center being 
 occupied by the irregular, black mass. 
 
 Fig. 13 
 
 Diagram Showing the Relations of the Optic Verve 
 Entrance to the Pecten and the Basilar Artery and 
 Vein in the Sparrow. (Wood and Slonaker.") 4 
 artery to pecten, which sends a branch along each fold' 
 ch choroid; on, optic nerve; peet, pecten; ret, retina- 
 ire/, sclerotic; r, vein fro-i pecten, which receives a 
 branch from each angle oi the folds. 
 
 :-JMii-t ' 
 
 
ANATOMY OF THE FUNDUS ORGANS IN BIRDS 
 
 The pectinate image seems to be displaced 
 by abrupt iiiovenients in the vitreous mass, 
 disturbances due probub'y to contractions of 
 the ocular muscles, external and internal. 
 
 As Kalt says, the pecten is a membranous 
 organ covered by a black pigment attache<l to 
 the optic nerve and projecting a variable 
 distance into the vitreous body. This organ, 
 studied and described for the first time by 
 Perrault, in 1876, received later the name 
 comb ipcigne). The tern, "comb" is not 
 exact since there are no stparute teeth; per- 
 haps "fan" better describes the appearance 
 of this organ. German authors still call it 
 the "fan" (Faclier). 
 
 Except in the Ostrich, where it has the form 
 of a cone inserted into the optic nerve and 
 <livided into two parts by a sort of white 
 partition, the pecten represents a triangular 
 or rectangular pigmented lamina, whose plane 
 is directed down and out. 
 
 Generally it does not extend into the 
 vitreous beyond the intercalary zone of the 
 sclerotic, and it is only exceptionally, as in 
 the Goose, the Swan, the Stork, etc., that it 
 reaches the crystalline lens. The comb is 
 made up of a lamina folded upon itself and 
 producing, in a transverse section, a markedly 
 zig-zag effect. The nund>er of plications varies 
 from 5 to 30, averaging 16, as in birds of prey 
 ami Gallinacea;. The writer and Slonaker 
 counted 18 folds in the English Sparrow. 
 
 Among the Owls, the length of the comb i- 
 J mm. >it the base; its height, 4 mm. In the 
 Stork the base is 1^ mm. long; it is 7 mm. high. 
 Kalt believes the pecten to be essentially a 
 vascular organ. It is composed of a network 
 of capillary vessels of unequal d-'niensions 
 spread out in two or three superimposed 
 planes, whose mesh ni.iy vary in form and 
 dimensions. In the Goose the vessels are 
 nearly all parallel; the anastomoses are rather 
 rare and the meshes actiuire great length. 
 The thin connective tissue, which serves as a 
 support, contains free pigmt it. The entire 
 organ is enclosed in an envelope of endo- 
 thelium. 
 
 Kalt further thinks that the pectinate 
 blood-snnply is derived from the external 
 bran' he internal car .i.! which, imme- 
 
 98 
 
 diately after leaving the temporal, forms a 
 large plexus. The branches from this plexus 
 cross the sclerotic and re-unite in a single 
 trunk, which corresponds to the central ar- 
 tery of the retina in mammifers. This trunk 
 extends to the base of the comb, where it 
 gives off several ascending vessels, that iK'iie- 
 trate the latter and form a large capillary 
 plexus. The venous Ijlood is relurned by a 
 large choroidal vein which perforates Hie 
 sclerotic a short distance towards the middle 
 of the comb. Note, also, that it makes at 
 the level of the ocular groove several variaiile 
 anastomoses with the plexus of posterior 
 ciliary arteries. See Figure 13. 
 
 According to Beauregarde the pecten is 
 allied to the choroid; it appears after the 
 fourth (lay in the embryo of I lie Hen. 
 
 The fiiiirtioii of th" pectni has from lime 
 to time been variously interpreted. It has 
 been considered particularly as an erectile 
 organ capable of displacing the crysti.. 
 lens and thus taking part in the accomuK 
 dation of the eye. Beauregarde, using the 
 ophthalmoscope, found displacements of the 
 organ and rapid vibrations synchronous with 
 the movements of the nictitating membrane. 
 But he noticed, above all, that the comb is 
 placed so as to intercept the rays coming 
 from the front and from above; that is to say. 
 those rays that reach the two eyes simulta- 
 neously. In catching them, the pecten is 
 supposed to suppress momentarily, in this 
 way, I)iiiocular vision, a condition which is 
 necessary for the more perfect use of monocu- 
 lar vision. 
 
 No (loul)t the pecten occasionally serves as 
 a scrcer to protect t.he retina against the rays 
 of the sun. Observation of the attitude of 
 the lien's head, when exposed to the sun, is 
 favorable to this supposition, as, also, the 
 slight development of this organ among 
 nocturnal birds. 
 
 Another hyp .thesis, which seems plausible, 
 attributes to the comb the role of an organ of 
 nutrition for the vitreous, and makes of it an 
 appendage of the ciliarj- body. It has al.so 
 been suggested that it is an organ of excre- 
 tion, charged with maintaining the intraocular 
 tension. 
 
 'liMrm t}9WiHn&»«fcPK7.W2Mi* ;urf:l.-s: 
 
n 
 
 Friiiiz tl,)os not Ik-IiVv.. tlu.t tlic fii„. stnic- 
 l>ir.. „f fh.- I,ir,r. iMTt.-n has, as y.-t. Ihh-.i fullv 
 'l<-«r,l.,.,|. The striKt.iral arradKi-ment il. 
 Nn.lhio shows it to ho .lifforenf from othvr 
 >ir.ls. ,vl„.,v It ,s,,ri„Ks as a sort of wriiiklr.l 
 '•■Mf from Ih,. paj.ilh. an.i has an vuhr^vun-ut . 
 wlu.'h K- tmns th,- •■I.ri,l«,.." which n.ns 
 ^'lo'iK th.- .-ntirc margin of H„- ,,,h(,.i,. S,.<- 
 liKurr n an.l I'h.i,. I. The fohls are 
 «rl,|,..l toK,.|hor l.y this l.ridg,-. so that thov 
 <an only Im. smooth.',! out l.y ruttinK awav 
 thf la t tor. 
 
 Til.' liixMofiiral xtnwiure of the liird-x ,rctc„ 
 has l.o,.„ inv.'.stiKat.'.! I.y Mihalkowics. D.-ms- 
 s.'nko. Born.! an.l others. H.'rn.l .iaims that 
 the IK- ten is not primarily of m.'s.j.j.'rmal 
 oriKin an.l an ap,,,.n,lix ..f the .horoi.l. as was 
 fornu-rly hehl (In Kessler, for instance), l.ut 
 IS really a .lerixative of the retina or of the 
 <)|)tie nerve; in sh.irt. an otFshoot of th.> 
 eentral nervous sysl.'ni an.l, eon.s.'onentlv 
 of Ih.' eeto.lerm. 
 
 Franz maintains that the p.'et.'n is a s.-nse 
 organ, assisting in the regulation of the intra- 
 oenlar pressure an.l the act of a.'eonimo.la- 
 l'">>. On the np,„'r .snrfa.'e of the p.'ct,.n 
 
 Ihat is <m the "l.ri.lg..," Franz f .| fi|,,- 
 
 I'lenls that eii.l th.-re in elul.-shap.M. „o.hVs 
 sirueturally l..'tw,-en ,.igmenl.'.l nu.l.'i a:i.l 
 'ell -uielei, .in.l h,' believes we may look up.m 
 t!:.' pecten primarily as a glia-stru.tiire, an 
 '.pin.on also hehl by nickniann an.l v 
 H..s,.n. .^till. Franz will not say. nor ,1,„.' 
 JJIockn.ann, that ther.' is to be foun.l in the 
 pt'oten any convinring .'vi.ienoe of th.- pres- 
 ence of true nerve filani.'nts. 
 
 Franz an.l Ilushke point .n.t that the pect.-n 
 IS all the more dovel..i,e.l the nior.- th.' bir.l 
 makes u.se of monocular, an.i less of binocular 
 vision; that the pecten of Song-bir.ls is larg.- 
 an.l rich in wave-like fol.ls, while the much 
 faster flying Swallow, with b.'tt.'r a.'cm- 
 ino.lation. has a more poorly .l.-veloiM'-l pe,- 
 ten. The Owls, also, with their small in-cten 
 nave binocular fi.\ati.)n. 
 
 Both in Birds and Reptiles th.T.' is a close 
 lonnecti.m between the pecten and the -■ c- 
 oiis; 111 other words between that organ and 
 the margins of the hyaloid .'anal, or slit, in 
 which it IS, as it were, inserted. 
 
 THE FUNDUS OCULI OF BIRDS 
 
 Franz d.H-s not f,>el certain about the vas- 
 euhir supply .,f the pecten of ihe Bird Uv 
 I'eliev.'s, iiowever, that the bloo<lv..ssei that 
 rnns along the base of the ,H-cten giv.-.s off 
 bran.'hes to the folds las shown in Fig I.-)) 
 ami. to a less extent, t.. Ilie |X'.'tinate t.ri.lge. 
 Ilie main vess.'l is to be r.'gar.led as the 
 artery (atferent vessel) .,f the pecten 
 
 We find glia-growths like lii.,s.' of the avian 
 pecten .'inanating from the papilla in many 
 Mammals and which pr.'stnt the same char- 
 a.t.-rs as thes,' organs in Reptiles. In the 
 ey,' of Anij)hibians and Fisiies tlierc are no 
 such glia-growths. 
 
 After many .iissections and much considera- 
 tion ..f th.. finer anatomy of th.' ..rgan Slonak.'r 
 aiKi the writ.'r .lo n..t r.-gar.i the avian pect.'ii 
 as anything more tlian a s.'ri.-s of blo.jdves.sels 
 «itli a deeply i)igmente.l framework ..f gha 
 hbre..: and ceils. So far we have been unable 
 to find in numer.)us serial .sections of the 
 Sparrow s iK'cten (or in that of anv otlier bird 
 so far examiiu.l by us) d.'finite ciliated struc- 
 tures, sensory bu.ls. .,r any other app..ar«nce 
 t lat would justify a l,..|i.'f oth.'r tlian that 
 this organ. deei)ly pigment.'d to absorb tlie 
 liKht rays, has any fun.ti.,n a|)art from tiiat 
 of a earner ..f nutritive pabulum, chi.-Hv to 
 the vitrous an.l ant.'rior lay.-rs of tiu- retina 
 It may cliang.- its jjosition, a.tual or n-lativ.- 
 during acommodathm, but it has no ..Ihcr 
 e..nnection witli the accomm.Kiative act 
 Tiie covering of all its fan-like f.jlds is e.,n- 
 tmuous and i.lentical with the hvahiid nieni- 
 bran.. or menibrana limitans of tiie retina 
 "e di.l not find in the Sparr.)w .inv anasto- 
 nioses between the vessels .,f the p-'-cten and 
 t he other ..cular structures. The branch .)f 
 the o|)hliialmic artery that enters the eye- 
 l>all .'hwe to the optic nerv.- sh.'ath (to pe'ne- 
 trat.> the huter at the plane of the .sclerotic 
 coal) IS tlie ..nly afferent ves.sel-suppiv of the 
 pecten that w.- were able to .lemonstrate 
 eith.T by gr.Kss .iis.section or in serial micro- 
 scopic .sections .jf this region. 
 
 In the .same way there apfwars to be onlv 
 one efferent vein which may, iiowev.'r, liave 
 r.-c.'ived oth.'r venules bef.)re its exit from th,' 
 globe, .several millimeters distant. These two 
 latter observations are, however, based on an 
 
 
 i«Ti»"BiT-»jL^' 
 
AXATOMV OF TFIE FUXDIS ORGANS I\ BIRDS 
 
 inconiplftc (lisvclion of llic purls hikI may 
 hv iiiii(!ifi<'<| lattT. 
 
 ]t\ lliis ju(l«niriit, if we rcjiil liini iiri)jlil. 
 Tn-ncliiT Collins, to somr cxlcnt, concurs. 
 In liis Krasniiis Wilson Lectures on the \nal- 
 oni.v an<l I'atliolojry of the Kvc lie remarks 
 lli.il "in other animals than Mammals and 
 in tlie human fetal eye there are sources of 
 nutrient supply to the intraocular structures 
 in place of or in acMition to the ciliary Ixxly."' 
 He adds that the pigmented, plicated strnc- 
 liir<' of the bird's jM-cten '•closely resemlih-s 
 the ehoroiilal coat . , having, how.'vcr, 
 a rather finer capillary plexus. Minis, there- 
 fore, not only possess well-formed ciliary pro- 
 cesses hut also ;i special vascular arran},'emcnt 
 ill the vitreous ciiamlicr." 
 
 AccordiiiK to O. Zietzschmann. also, the pec- 
 ten is covered hy a delicate meml)rane which 
 is continuous with the inner 
 limilinfj memlirane of the retin.i. 
 The Moodvcssels. accordinj- to 
 him. Iielon;; to the ciliary sys- 
 teui and are hrauches of those 
 supi)lied to the optic nerv<>. 
 Leher l)elic\es the pectin.ile .o- 
 tery to lie (he li<imolo^'ue of the 
 li>aloid artery. 
 
 Finally, it may ix- added that 
 there arc n.) '.iood vessels in the 
 Hinls' retina and the vessels of 
 the |>eclen do not. conse(|uenliy. 
 arise from a central artery of 
 the oj)tic nerve as in Mammals 
 since tliat, too, is wauling;. 
 
 This arratifiement. inasnnieh 
 as the (ipa(|ue vessels tlo not. 
 as in most Mammals and other 
 Vcrt(l)rata', interce{)t the rays 
 of lifjhf impinginf; on tlie per- 
 cipient elements of the retina, makes for a 
 mon- distinct and measurahly clearer-cut 
 iniaj,'e of the ohject visualized hy the avian 
 brain. 
 
 Compamlirc ophthahnoscopii of reptUiaii 
 fundi. With the aid of Mr. Ilea.l's brush and 
 by courtesy of Dr. Linds;.y Johnson the writer 
 is .-djlc to compare a few typical fundi of 
 Rejjtiles with those of their ancestral cousins 
 the Birds. 
 
 85 
 
 It re<iuires only a glance at these pictures 
 to feel assured that the eyes of that nocturnal 
 replih- tlie Turkish (ie.ko il'hit.' LIX). 
 whatever els.- may be said on the subject, 
 are more decidedly avian or. rather, more 
 ornithosaurian than are those of the Horned 
 Toad (Plate lAi. or Indian Coljra i Plate 
 lAI), whose fundi belong more distinctly to 
 other vertebrate types. These last-named 
 possess definite retinal vessels (that issue 
 from a circular optic i)apilla), an.l they have 
 no pecten or at h-ast th<' mere suf,'i;<'slion of 
 one. (•om])are Plate lAI with Fij;. 14;j; 
 and l'lat( lA with Fi^. I U, which sli.os' 
 the nsembhince betw<>en the Cobra fundus 
 and that of the Hed«e-IIof;. while the eye- 
 ground of the Horned Toad sunfjcsts tl it 
 of the Virginian Opossum. For further com- 
 parison a diaKrani of an ichtliyan fundus 
 
 Fig. 14 
 
 OpbtlialinosTOpic \-ie«- „f Ur. F.nulus of tlie Fi>l. <,a<l,u merlaiujw, 
 (After IWuregarde.) Tlie proeessus faleiforinis .l.liuk) runs ti.e «liol,- 
 length of the (white! optic nerve-head, at the iK-riphery of which are seen 
 six branelies of the hyaloid arterv. 
 
 oculi (Fij;. 14) — that of (iailiis iiierhnKjim ~ 
 is shown. 
 
 If one may draw any conclusion from such 
 sparse material and from such an incidental 
 examination of the subject it is that whatever 
 of common oripn the avian and reptilih.i 
 clas.ses may have originally had the ornitho- 
 logical branch left the parent stem with a 
 subdivision of tlie Lacertilia and not with the 
 Ophidia. 
 
 ;r>»«r-.r.ir VK'.t:j««K!"flE%i«:j£X' v<tz:i!iK5sa3r. -msii»'-iiu.:^^.tit ns^"'!'. 
 
 . <r.-*ayK. i. •^««iBii« far^JT 
 
ClIAITKU V 
 
 OF THE VERTEBRATE EYE BY MEANS ^^^ 
 OF THE OPHTHALMOSCOPE 
 
 Since this .sut.ject. nlthouRh fan.ili.r f„ 
 opht ha nu.I.,gi.sts (..ruli.ts), is rnn-lv mnU-r- 
 sto(Hl l.y naturalists in gen.Tal, and rsm- 
 cmlly not h.v ornithologists, a l.riof rovi.-w of 
 ophthalmoscopy us practiced on the verte- 
 •rate c-ye may not l,e out of place in a work 
 like this. 
 
 The ancients notice.! that the eyes of some 
 nninmls are. under certain conditions, bril- 
 liant in twilight or .semi-darkness. Although 
 he did not attempt to explain the phenon.e- 
 non. I hny remarks that the eyes of animals 
 that see at night - cats, for example -are 
 radiant and shining, an.l that the eyes of 
 the she-goat and the wolf emit a light like 
 tire. This fact continued to he noted through 
 the succcH-ding centuries and was commented 
 on more or less by other obserxers. Jean 
 -Mery of 1 ans, who in 1704 immersed a cat in 
 water, beheld in all its glory the fundus of 
 that animal s eye, inclu.ling the opti< nerve 
 entrance, the retinal bloo.l ve.s.sels, and the 
 remarkable coloration of the retina and cho- 
 roid. AKp. did not giv a pro,,er explana- 
 tion of this phenomenon, but five years later 
 <!<■ la Hire showed that the refractive power 
 of the cornea is neutralized by immersion of 
 the animal s eyes in water, so that all ravs of 
 liglit reflected from a given point of the fundus 
 emerge from the pupil not as parallel but as 
 divergent ra.vs; con.sequently the fundus im- 
 ages can be seen as if one were looking at them 
 in the dcpth.s of the eye through air 
 
 r J^" fj!"'*"^ °^"" <"■ Background of the 
 Internal Eye in Man. Glimpses of the human 
 
 (26 
 
 •HMilar Ulterior wer.- oblained from time to 
 line but It Wi,s not ,„,|il the year 1847, when 
 
 "Mbbage, an E„,jli,h mathematician, exhibited 
 to Wharton .Jones, a well-known oculist < f 
 his day, the model of an instrument by 
 means of which the interior of the eje coul.l 
 be thoroughly examine<l. It (consisted of 
 a small, plan.-, glass mirror from whose centre 
 a portion of the .silvering ha,l been removed, 
 i ins .levice was not made known to the world 
 until 1854. iK-fore which date the cele»)rated 
 phy.sicist, Hermann von Helmholtz.pu'-.ished 
 in 1851, a description of an ophthalnK.scom' 
 whu'l, enables the observer to .see with eas.. 
 all the parts in the background of the eye 
 
 The Ophthalmoscope. The original Helm- 
 holtz instrument consisted of four thin i)lates 
 of glass carefully polish,-d. screwed toj,etlier. 
 fastened at an angle of fifty-six degrees to a 
 t)rass disk, an.l forming the hypothenus.- .,f 
 a right-angle.: triangular prism. Th.- other 
 si.les of this hollow prism were ma.le of metal 
 an.l all carefully l)lackened inside. The brass 
 •iisk had a hole in its centre and an arrange- 
 ment to ,)lace a concave l.^ns over if for 
 n.)rmal eyes IWmhoItz u.sed a \o. 10 (4 n ) 
 glass. The light from a lamp falling on the 
 gass plates was in part reflected into the 
 observed eye, while the observer, looking 
 throu„'h the concave lens and the opening in 
 the brass disk, received the returning ravs in 
 his own eye, and was able to see the fundus 
 w(!akly illuminated, but still distinctly. 
 
 The instrument now in use for examining 
 the interior of the eye more ncarl ,embles 
 
 '•^A^^mju:. 
 
OPHTHALMOSCOPY OF THE VERTEBRATE EVE 
 
 llic ori>?iniil nphtlmlriioscopf of HahlrnKf lliHn 
 lliiit of Hclnilioll/. 
 
 It consists «s»<>ntially of a coinavo mirror 
 of ahoiil « (111, fwiis (inouiilfd on a handle). 
 with u small (3 mm.) hole in the o-nft-r and 
 so arranged that a wries of eoneave and eon- 
 vex lenses may Ih- presented to (he (.peniiiR 
 for the purpose of nentraliziiiK tiie refractive 
 error of the ol.server's and the observed <\e, 
 thus Riving a clear view of the fundus details. 
 There are numerous opiithalnioscopie niod- 
 eU in the market today - iniproveinents mi 
 the early inventions l.ut the iiistrunieiils 
 of F-orinK and Morton are, perhaps, the favor- 
 ite forms now in use. Illustrations of Ihce 
 are ^iven in the text. S'e Fijjs. 1.5 aixl W. 
 
 As tlie piirpone of an ophlhalmoncupic cx- 
 aminalion is to see a.s much as possilile of 
 the interior of the eye under observation // 
 is (Imirnble In dilate lite pupil; -in the cas<' 
 of maniniai.s 'hi.s is aecomplislied by inslillin;; 
 into the eye afropin, homatropin, euphthal- 
 niin or some other mydriatic. 
 
 Before the invention of the sflf-liimiiioiin 
 or eleclric ophthalmoscope (Fig. «1) the source 
 of illumination of the ocuhir interior was a 
 gas jet or electric bulb — preferably an nrgand 
 lamp — stationed in a darkened room, and 
 placed on a level with the eye to the side of 
 the head. 
 
 In examinations of the human eye the 
 observer sits opposite the individual whose 
 ocular interior is to be explored, and placing 
 the mirror close to his own eye and about 
 4() or r>0 cm. from the eye to be examined 
 •^fleets the light upon the latter, while he 
 looks at it through the small opening in the 
 ophthalmoscopic mirror. In very short- 
 sighted and very long-sighted eyes, but not 
 in normal ones, the vessels of the retina, the 
 entrance of the optic nerve, etc., can be more 
 or less distinctly .seen. 
 
 The details of the retina, choroid, etc. (or 
 fundus), can be seen in two different ways. 
 In the indirect method, as applied to Man and 
 most other vertebrates, the observer, seated 
 as shown in the cut (Fig. 16), holds a strong 
 (IC i>.) convex lens about 10 cm. from the 
 eye under examination, and between it and 
 his own, when a clear real image of part of 
 
 •7 
 
 the funiliis, inirrtrd and magnified about four 
 diameters, appears in the red light of the 
 pupil. 
 
 In the diriTt mrilntd d'ig. 17) (J„. observing 
 eye must be placed as close !o the ol)served 
 as the inlervenlion of Ihe mirror will allow, 
 when a rirliiiil image of a still smaller part of 
 
 Fit?- IJ 
 Ix>ring Ophtlialmoscope 
 
 the fundus is seen, hut erect and magnified 
 about fourteen diameters. 
 
 Direct ophlhalmnscopy. or Ihe examinatiim 
 by the upright or erect inuige, is illustrated 
 by means of Fig. 17. A side lamp (L) is 
 used, the rays from which are focu.se<l by the 
 perforated mirror of the ophthalmascoix- (OO) 
 and thrown into the observed eye through the 
 dilated pupil (P). The rays of this |)eneil 
 now cross about X and impinge on the retina 
 and choroid nt (M) and cover the ocular back- 
 ground from B to B. Thence a sufficient 
 number of efferent rays are reflected and re- 
 fracted back through the ocular media of 
 both the observing and observed eyes to tlie 
 percipient elements of the former, at L. 
 
 Another illustration (Fig. 16) shows indirect 
 ophthalmoscojry, or, as it is sometimes called, 
 the examination by the inverted image. A 
 divergent light pencil proceeds from the 
 
 n : 
 
 .-.■„ -t - 
 
 v^"-:-: 
 
 m 
 
 mrf 
 
«8 
 
 THF Fl'N'nrs (Kn.I Of BIRDS 
 
 'H), Hlinin 
 Iff u.. Ii 
 the ciTitri' II 
 
 ■■liowiriK lln- 
 
 FiK. irt 
 
 Irjiliriil (>(ihtlmlm(Mcj>py 
 •■.iir«. „f th,. li^,lil my, fr,„n llir l,„np, I,. |„ 
 
 ""• rrlina at Zv. („ U- fi„„l|v „.H.h t .1 . I ' V""'" '"""' '"•""'' ''> ""■ 
 
 -f tl... mirr..r, (X). ' ' '" "'" ''>'■ "' "»" "'-•"-^ »' !•"• "l"'..i"B in 
 
 lump. L. i„ the ..plithdlnidsroiH- mirror ()0 
 which f.K-iises tl.f rays .,1 '■ Tlu-s.- Mil.-' 
 M-qm-ntly .liv.TK.-nt rays an- lu. aia.l.- paral- 
 l<'l l.y tlif convex I,.,,., an.lar.' lliusl.rouKlit ton 
 f<HU.s on tl..- n.lina-<.l,oroid l,y the .liontrir 
 "pparatus o, the ohserve.l eye. Then.e the 
 rellecled an<l en.erKenf rays follow the smie 
 path aii.l ,„„H. to a f.Kus, ..i X. in the .-ve of 
 the examiner who will si-e an inverted aerial 
 iniage of the observed fundus. 
 
 The ,./,r/nV .■>,■//. ilhn,nnoliny ophlhnlmn- 
 ■vropr .hirers fron, the types just pieture.l in 
 that If earri.'s its own lit;ht s.Miree — a l,at- 
 
 t<Ty in th.- han.ll.-. It is ,H.,,,liarly mlapl.-,! 
 lo the .•xannnation of th.- .-v.-s ..f animals 
 '.ther than Man. One is enal.L.I ihrou«h 
 this improv.-ment not only f. .lisp.nse with 
 the eumhers.mie si.h- liKhl l>ul to mak.- satis- 
 fa.tory examinati..ns of th.- fun.lus ...uli in 
 "Illy partially darkenetl surn.un.linKs seri- 
 ous e..nsiderations in .loin^ fi.-ld work with 
 ^M s|H-ei<-s. A picture of th.- jat.-st ni.uh-l 
 of the self-lumin.)us oplilhalnios.„t«. is shown 
 in Kif?. i\. 
 
 The fact that a consid.-rahle jx.rti.)!! .,f th.- 
 light tlir.)wn into th<- int.-rior of the ,-ve 
 
 Dirett Ophthalmoscopy 
 Diagram showing the course of the liirht rav, fmm »k i 
 .hence they a.e refle,.ted directly upon the oW v uTet n TL'i^ '"th'^ "'""'• ™' 
 reflected through ,he opening in ,he mirror, OO. J^^Z^^, J^^ 
 
 the 
 
 Wi^^m-^Sl-^MM 
 
 felf" 
 
OPHTHALMOSCOPY OF THE VERTEBRATE EYE 
 
 Fig. 18 
 Relativp Position of Observer and Oliwrv.-.! in Direct Ophthalmo«x)py 
 
 Fig. 10 
 Relative Positions of Examiner and Examined in Indirect Ophthalmoscopy 
 
 m\ 
 
 ii'i 
 
m 
 
 THE Kl NDUS OrULI OF BIRDS 
 
 IhroiiKh the- pupil in rf(l.< l,-,l liy fhc Mrilr- 
 liirr. ..f (I,,. l.mkKn.iilt.l int.. l|,i. ,.,<• „f Jhr 
 ..l«,.rx,r ,n iIh- primipl,. of Ihr (>phlhalin.«- 
 <<>|M'. M,,ri-,.v<r. Ihix r<-(l,T»i(.n. or ratJu-r 
 rtfra.iiuri, nf i|h- iiiriHcnt ruy*. tii.Hlitii'il \,y 
 
 Mortim (>pli(halniiiHc<i|M' 
 
 the .Jmrarter of IIr- nu-dii. throiiRh wliid, 
 they pnss furnish tlu- wonderfully vjiric.l „n.l 
 ••(.lore.! pictures ohscrved in the .Kuliir l,i„k- 
 KroiuKl., of all the verlehrntes. 
 
 This brief account of the ophthalnMiscojH. 
 and Its method of employment is oir.red for 
 file benefit of those who have not use<| the 
 instrument, hut no do.scrif)li(m of ophthal- 
 moscopy will much aid the zcH)loKist in ac- 
 •luiring a practical knowledge of its applica- 
 tKin in the actual examination of animals' 
 eyes even in the favorable surrounding of the 
 darkened laboratory. Only a number of 
 months spent in the exploration of the eyes 
 of such domestic animals - including Man - 
 as are most readily aewssible and easily ob- 
 served, followed by ophthalmoscopv of wild 
 species obtained in field work, will 'make an 
 exjM-rt of the stu.l.'nt. While the writer will 
 
 not nuy thnt « prootical knowledge of throph- 
 thHlmoscofK" in f»»fntial to the training of thr 
 Mienliti.ioologi«t yet it ii an instrument that 
 fiirnishr* prrei«. and valuable information 
 which the naturnlixl cannot afford to ignon-. 
 
 A. The Fiindut (hiiU or background oj the 
 Inhrnal Eyr in Man. 
 
 On account of the extensive literature on 
 this subj.K-1 and lHtau«- the human fundus, 
 normal and abnormal, hait Ut-n .arefully and 
 thoroughly explored by many ..bservers for 
 over half a «entury no study of comparative 
 ophthalmology in complete without at least 
 a short account of the ophthalmoscopic fin.l- 
 iiiffs in Man. In the writer's K,wy,-l„,»;lla „f 
 OlMmlmiihg;/, \„\. Nil, r>. .Ml. 5 ,7 .i,,,., 
 M«H.re.i Hall gives a good account of the 
 fH'BUtifully col(,red ophthalnios<opi<. picture 
 one seen in the <l,.plhs of the human eve. 
 The part-s of chief interest in th<- human fun- 
 dus are the optic disc, the bhwKl-ves.seN, the 
 macula liitca, and the choroid, and they fur- 
 nish a .satisfactorj- comparative study intro- 
 diictory to n consideration of avian fundi. 
 
 KliTtrir SolMumini.iis Optithalmoscope (de Zeng). 
 
 The optic disc is situated about a mm. to 
 the nasal .side of the posterior pole of the eye, 
 and is the point of entry of the optic nerve 
 into the retina. It measures from 1.4 to 1.7 
 mm. in diameter and is generally circular or 
 ellipsoidal in shape. Near its centre is a 
 
 ^i^- 
 ^^i- 
 
 ,' -v. 
 
 ^ji,'^^}fs^:M 
 
 ^k>%\ I ■■■' .■2»:i f ^. «?^!\'- -•? '•a'»5v:ja«i» w^tsmx: 
 
OPHTHALMOSCOPY OF THK VERTEBRATK KYK 
 
 SI 
 
 iloprt'Miiun, th(> phykiologir <>xcutiiliuii, whiili 
 marks lh«' divornpncv cif iiprvi--iil>re«. Tin- 
 fxcavatinn i» funncl-xImiM'H, tl' Imw Im'jiik 
 Hiili-rior. A trncr of Ihf liyiiioid arli-ry of 
 fctn] lift- is tN-t'asiunally Mfii Uerr a.i u thrfiiil 
 iif i-onrHftivi- tisDUc running frnni tlii> papilln 
 into I hi- vilr«'ou«. SiirrouiuliiiK flu- luipilla 
 itrt- two riM)(^: iin iniirr, iIik' Io i-xpoiiiri' <>f 
 
 (ilimt, iliM- to thi^ fnct that i .<■ nmlulUry cover- 
 iiift of t lie uxiit-oylinili'rt t>\ i .1 1 in I he fitire-lnyer 
 of the retina. In tmh 11 iiixe the fumluit showi 
 a pHti'li of a lirilliunt white color extemlinK nut 
 from the ili.ie. (ienerully the white area in in 
 rontart with the i|i<i<-. It rarely oocurt that 
 the opn<|U)- fil)ri'!« are fotinti at a K^'nt di'ttance 
 from the nerve-heail or that they iK-rupy a 
 
 Kg. « 
 
 Diagram Showing the Relations of the Parts in the Human Fundus Oruli. a, sclera; b, choroid; 
 '. macular region; i, optic disc; 3, superior nasal artery: 4, inferior nasal artery; 5, inferior 
 temporal artery; 6, superior temporal artery; T, temporal side; N, nasal side. 
 
 e, retina; 
 
 the sclera, is whiti.sh, and is culled llie scleral 
 ring; and an outer one, due to the showing of 
 choroidal pigment, is named the choroidal 
 ring. At the bottom of the excavation a 
 few dark spots arc seen, from the gray stij)- 
 pling of the lamina crihrosa. In color the 
 papilla is grayish-pink or reddi.sh, and stands 
 out in marked contrast to the reddish-yellow 
 of the remaining parts of the fundus. The 
 color of the papilla varies with the age and 
 complexion of the individual, the color of the 
 surrounding parts of the fundus, and with 
 the illumination used. A common anomaly 
 is the presence or persistence of opaque nerve- 
 
 large area of the fundus. The physiologic cup 
 or depression may occupy a large part of the 
 nerve-head, but never extends to the scleral 
 ring. Under normal conditions inany varia- 
 tions are seen in the size and depth of the cup 
 and in the arrangement of the lilood-vcssels. 
 
 The blood-re.i.iels are the central artiry and 
 vein of the retina. They run in the nerve- 
 fibre layer of the retina, and often present 
 variations of distributic » The middle of 
 the fovea centralis has n ' •'■ 'od-vessels. 
 
 While it is often staled that the retinal 
 vessels can be seen on ophthalmoscopic ex- 
 amination, as a fact it is the column of blood 
 
 ■■r^^''n;?lr'^'')t? «*f *f ,«'i?-'V="«::':C '^''-- 'i^-% 'r^-yn K'.-^ ■ 
 
.mr 
 
 Si 
 
 and not the ve.scl-wall. which i.s visible. In 
 the larger retinal vessels the l.l..od-eolu.nn in 
 he arteries is hriditer than (hat in the veins 
 In the snu,ll,-r l.-.,„.hes this .lifFerenee is less 
 ■narked. The l,ri«l,|,r e.,l„r ,.f the arteries 
 js due to the presence of a central streak of 
 I'Kht. which IS less marked in the veins. The 
 cause of this liKl.t-streak is not .Icfinitelv 
 known. The retinal artery, under normal 
 oond.tions, rarely p,>lsat..s. I,„t venous pulsa- 
 tion occurs spontaneously in from 00 to 75 
 per cent of normal eyes. 
 
 Besides the l.Io^d-ve.ssels enumerated 
 •iDove It IS necessary to mention the cilio- 
 retuHd ,-es.seh. The ■ are comnionlv small 
 solitary ves.sels which arise from the circle 
 o Haller. and emerge .* the Icmporal l.order 
 of the disc. Such a vessel may come from the 
 central vessel in the substa,K.e of the nerve 
 and may be of larger size. (Jenerallv it sup- 
 plies blood to a .small area between U,e disc 
 «nd /nacula. Cilio-retinal vessels are present 
 in from 10 to KJpor cent of normal eyes 
 
 The mncuL lutea ("yellow spot " of Soer ■- 
 ■".•nuK) ,s situated about .'! mm. to the outer 
 side of the optic-nerve head, and sliKhtlv be- 
 low the horizontal meridian. It is a "spot 
 'la.ker than the surrounding retina an.l 
 apparently devoid of blood-vessels. It is the 
 area of greatest visual acuity. The centre 
 of the macula presents the foveal reflex, while 
 he periphery shows a whitish, glistening 
 HR, or halo, known .-.s the macular reflev 
 U.frerenees m the appearance of the macula 
 .n iiH ivduals are doubtless due to several 
 (mostly domestic; eaus,-s: to the .lilfercnce in 
 methods of examination; to ditrerenees in the 
 age, complexion, race, and refraction, as well 
 as to variations in the distribution of pigment. 
 There are several forms of (ophthalmoscop- 
 cally vi.s.bhv macular rings. Lindsay Jc hnson 
 states that the most common is a bright 
 sen, ,ll,.,ting reflex resembling shot-silk, verv 
 ■narked in dark eyes, scarcely visible in fair 
 oiies, an.l best .seen with feeble illumination. 
 1 his ring ,s supposed to be due purflv to 
 reflection from Muller's fibres, where ihev 
 expand into the internal limiting membrane, 
 and partly to the fibrous sheaths of the vessels 
 which lift up the retina over-lving them 
 
 THE FUXDrs OCULI OF BIRDS 
 
 Tlie/o,ra/ reflex is found in the centre of tlie 
 macula as a verv small ring, or as a circular or 
 hor.sesh.K'-sha,H-o spot of light, or as a "comet- 
 lare. It ,s due to reflection of the edge of 
 the fovea. 
 
 The ehornid. While each ocular tunic con- 
 ributes something to the highly colored oph- 
 thalmos,.opic picture, the chief part must be 
 en'dited to t he choroid. Light reflecte.l from 
 he m.rror „f the ophthalmosco,K. pas.ses 
 hnuigh the transparent part of the retina 
 to the pigment epithelium, and is partly 
 absorbed, partly reflecte.l. Although the 
 piKuient layer belongs embryologi<.allv to the 
 retina, it generally adheres to the" retinal 
 sur ace of the choroid, and is accredited oph- 
 thalmoscoj.ically to the latter tunic Tho 
 .right ness of the fundus picture depends on 
 the amount of pigment. The greater the 
 I>iK|nent, the greater the absorption of light 
 and the darker the fun.lus picture. In the 
 ..egro and the native of India the fundus is 
 of a brownish, brown-red, or slate color, while 
 '■« the .Vnglo-Saxon, and particularlv in 
 l>lon.les. It is of a bright-red color. If the 
 pigment layer is very thin, the choroidal ves- 
 M-ls are correspondingly expose.l an.l arc seen 
 a.s a network of large, flat ves.sels, without a 
 l:Kht-streak, between which are spaces of light 
 or <lark color. They are .seen best in albinos. 
 It IS generally impossible to diflFerentiate 
 l.e ween the choroidal arteries and veins, 
 although at the equatorial region the latt.T 
 converge to form the venffi vorticosie. In 
 l-runettes the vessels appear as '-light streams 
 separatcl by ,|ark i.slands," because the spaces 
 are more deeply colored than the ves.sels 
 
 The srh-ra, which may be sjiokt-n of as tlie 
 panel on which the fun.lus picture is painted 
 ■s c..mn,only invisible, being coverci by th,' 
 "early .,pa,,ue choroid. Vet it is probabi,. 
 t .at in all ,.yes some light passes through the 
 ehor.,.d, an,| thus the .scl.ra has some in- 
 |h""nce on the ophthalmos.-opic picture, serv- 
 ■■ig to make it lighter. In albinos the scleri 
 appears as a white surface between the cho- 
 roidal vTssels. It is best .seen where the 
 choroi.l Ks ab.sent, as in coloboma, or patho- 
 logically as a result of destruction of the 
 retina and choroid. 
 
 ■r::r>.-^-^' 
 
 ■^: 
 
ClIAITEK VI 
 
 OPHTHA -M. )SCOrY OF THE Fl'NDl'S IX LIVINX; BIRDS 
 
 Tin-; nit'lliod employed liy the writer in ex- 
 iiniiiiiiif; tlie l)a<kj,'rournl of tlie eye in living 
 Hirds does not niiich differ from tli;it of the 
 physician in liis examination of human eyes 
 as described in the previous cliapter. 
 
 For a proiMT exploration of the vertehrate 
 fundus it is, as previousl.\; stated, hi^lily de- 
 siral)le tiiat tlie pupil Ic- widely dilated. 
 This is accomplished in M.m and other Mam- 
 mals hy such mydriatics as alroi)in, hom- 
 atropin, euphthalniin, etc., which hriiif; about 
 an enlarged pui)il inaiidy by inhibiting the 
 action of the non-striated sphincter muscle 
 fibres of the iris. In Birds, however, these 
 a,i;<'nls have little dinrt elfect on the striated, 
 voluntary, sphincter musculature of the iris; 
 hence they are of little value in an ophthal- 
 moscopic examination of most Birds. One is 
 oblified, therefore, to resort to such agents as 
 galvanism, nicotine, strophanthin, curare, 
 sliptiein, etc., and to such drugs (eserin. 
 alropia) as render the bird unconscious with- 
 out actually killing it. 
 
 In collecting the heads of birds for niacro- 
 seopical and histological studies the writer 
 found tliat satisfactor.v ophthahiioscopic 
 views of the fundi can be had a few minutes 
 before and after the death of the specimen, 
 during whidi period the pupil not only dilates 
 (/(/ miij-imiiiii but the bird does not use his 
 third eyelid. Many of the api)ended rcj)orts 
 were gathered in this way. 
 
 Owing to the peculiar arrangement of their 
 lacrimal apparatus (.s<h! the writer's work on 
 this subjeei) iiuids instilled into the eye (con- 
 junctival sae) of Birds run immediately into 
 the throat and gullet, there to be absorbed 
 and to produce precisely the same systemic 
 elfeets as if they were poured directly down 
 
 the throat of the animal. (Ireat care should 
 be used, therefore, in using eye drops for their 
 expected effect upon the visual apparatus: 
 if poisonous for the bird they may cause his 
 death in short order, and rare and valuable 
 specimens may be sacrificed to the ignorance 
 of the observer. The writer has not the least 
 doubt but that some of the so-called mydri- 
 atics or pupil-dilating drugs recomniende<l for 
 an exann'nation of the ocular interior of the 
 Bird act as .systemic intoxicants and not 
 specifically upon the iris muscles, as is the 
 case with the manmialian eye. 
 
 As :in example of this action of the so- 
 calli'd mydriatics on the eyes of birds the 
 writer once fell into the same error as other 
 still earlier observers in attempting to dilate 
 by atropia the i)upils of a Yellow Parakeet 
 {Mrlopttitlnriis iindulatiis). This bird w-as an 
 adult individual, .sex unknown, in captivity 
 for six months. In dull light the pupils 
 were -2. .5 mm. wide, contracting irregularly 
 to 1.,) mm. A single drop of a 1% .solution 
 of atropia sulphate put into the eyes appar- 
 ently dilated the pupils ad max (3 mm.) in 
 H hours, but as the bird was taken ill a few- 
 hours following the instillation (stupor, ver- 
 tigo, quick, weak heart and final unconscious- 
 ness) and died 30 hours after the use of the 
 <lrops, it is quite likely that its death was due 
 to the poi.son that ran into its throat from the 
 conjunctival sac. The writer had a similar 
 experience with a number of other birds. 
 
 The following notes were made of experi- 
 mentation intended to determine the best 
 mydriatic for the Bird's eye, especially for 
 field work. 
 
 Laboratory Xote.i of Experiments on the 
 Pupils of Passer domesticus. One drop of 
 
 [38] 
 
S4 
 
 •» to ,Hi,„i„„ „ „.,,„ ,„ I 'J,*: "-. "° '*" 
 
 •lisWv "Bro™-" ,„1 ' • ""^ '•""""■ 
 
 1 . »'"«8J in 4 niiniitos. l(i-9n . .. 
 
 very shght, if any difference in pu^s Vl"' 
 
 recovered in fi -^^ '" ""'^' """"'e but 
 
 recovered in five nnnutes so as to sit un in,! 
 
 Hv*.„....ner,p„;nrit';r 
 
 lay on its hJi- J^ .^oSBi'" w i min.; 
 
 diffieuhv de ,t Tn """■ i'-"*'''"^' with 
 
 left; sen;iSt;d^S:"'''"'^''^''"*^^ ''"''•' 
 March 30, 191 ^ "l -qn n ,. t. 
 
 1% n,.o/,-„ nVo Ihe leVev. M.' ""' "^^"P °' 
 All I '^''^ eye of three adult o 
 
 All became more or Jess "wobbV' in L 
 nnnutes, recovering almost entirely ?„ T," 
 minutes. At 4 p M t\,^ -, , . v in 15 
 
 THE FUNDUS OCULI OF BIRDS 
 
 iJight |)iij„| unaffected at 4 p m • i i .. 
 
 normal at 4 ... „ ""^ * ' ' *'• ''"'h Pupils 
 
 Jfarch 20, m}. Examined pupils in one 
 o- and two 9 1 1 ,; ♦„ 9\ ' „ pu|'"s m one 
 TV. - * 2 nim. in dianie»»r 
 
 They contract pron.ptiv in light to . T 
 Nicotin, both K- and ^r- *" ' '^ ^ """■ 
 the birds On A \ " "*"""* *" "''■■""'" 
 
 1010 V /• -^^ -^^ **•• -^lareh •iH 
 
 1912. Negative results at 12:00 
 
 purpose ^ "^""' °°^ -" "- for the 
 Experience has proved thnt tKo in 
 
 'ens (to make sure that there is in tin u 
 in « dark roon, Tl, , T" °" " '*"'' 
 
 assistant seated opposit^ ^ ''^ "" 
 
 In /fW «.or* both the observer and I.; 
 assistant may Wl on the earth under ^ 
 
OPIITIULMOSCOPY OF THE FUNDUS IN LIVING BIRDS 
 
 large, bl. k uiul>rclla, or make tiic examina- 
 tion in u darkened tent; in public or private 
 aviaries the examination can often be made 
 after sunciown. 
 
 A four dioptre convex lens must be placed 
 in front of the eyehole of the mirror. This 
 
 as 
 
 species that present invariable ophthalmo- 
 scopic pictures. It will be found that after 
 two or three generations of inbreeding, con- 
 finement and domestication, changes occur 
 in the ocular apparatus coincident with varia- 
 tions in other parts of the organism. 
 
 Fig. 43 
 
 Method of Examining the Bird's Eye with the SelMumiuoiu 
 Elet'tric Ophthalmoscope. 
 
 "indirect" method (see, also, page 29) gives a 
 comparatively small, inverted image of the 
 ocular fundus. It corresponds to the low 
 power lens which one uses in the preliminary 
 examination of a microscopical .section. 
 
 The examination by the erect image will, on 
 the whole, be found the most satisfactory 
 method, although, as in viewing the human 
 fundus, it is advisable to use the indirect plan 
 at the outset. The self-luminous ophthal- 
 moscope is quite satisfactory for both these 
 purposes. 
 
 In making an examination of the avian 
 fundus it must be remembered that it is wild 
 
 The facility (or otherwise) with which the 
 ophthalmoscope can be used depends, in a 
 large measure, upon the conduct of the bird 
 under examination. For instance, it is im- 
 portant that the macular region be carefully 
 explored and it can generally be seen, but 
 throwing the light on this very sensitive area 
 often makes the animal restless and the 
 greatest gentleness should be observed to 
 keep it quiet if a complete examination is to 
 be made. Most specimens, not excepting 
 the Eagles, Hawks, Vultures and other large 
 birds can be hypnotized and so quieted for the 
 period of an ophthalmoscopic examination. 
 
 
 Zi. L»^\^M^'a!Xgrm!SES\U.'I^-.frt^-f'f'''lWf--m~ y-Mu*t '"iT.^J»rf'^4«..l 
 
 f'S'^^!? 
 
 ^'vjitmsja 
 
■Mi 
 
 Wr.l relaxes i ,1 " ■"*'?^'-^- '••■'•^«"'- ""• 
 
 "^'■"lly l.e turned i„ 1. 1 ",'';""' '."" 
 t.^-iUi.M.bserver/s:eVi'T '''■"•''"' 
 
 of occasional mntr ♦ "",'""' •'"«! ''('cause 
 
 .L.- .;;.;.;;';;,;;:;:'•'■'■'' ^ "■"-'■■» i 
 
 As an extended study of the eve , f i- ■ 
 •^"•ds is not without ;i- / ^-^f^of livniK 
 
 buf'irCr'i.ii.jrvr"'^-^"'^'^-'-"™- 
 
 '^ "" °^ Bentley's California 
 
 THK FUNDUS OCULI OF BIRDS 
 
 ^l^iascope had i,l-,v. I . r''f-'"'>""<'U.s 
 
 ''^■-•'■''-^inuMvereinlpr.!. '''''•''*■' 
 
 -""".;ronepos„ion«,;,rji ;;:;;;";:; 
 
 "iradion, Hindus apnearanc.s «(,. 
 n.a.le without .liffieullv Fin ! i ""' 
 
 ^<' '"inutes or half an our' whJ.',;^'" "'"•'* 
 "/'-■.^"Pleted. the bird refund to ;''''*■'" 
 
 --and had to he pushed ;:rt£,^";,::; 
 
 "'-nu.|.eean,e his lively .elf asa "" 
 
 "•"1 tax the p<Ts,neran,.e of fh . '"■'' 
 
 the utmost Jt ,-. , "f »he observer to 
 
 '"W. also -.r.. )i e ■ .^*''^™"<(- Annov- 
 
 -siot IL- , *''^^"g'"^•^• reflections an.l 
 
 snoi-silK colors that nl'iv n,-,... .i 
 areas in some b,r,l . . ' '^ ""^ '■'''"">1 
 
 -rnersant w^). "';'•'' ""' ^ ^^ftVientiv 
 
 '■"''■'-;i:;tr:ti;u'dr''"'"^^'''''- 
 :f ;; e;i.:^b;;;^ 
 
 --o.eSt-2-----^ 
 
 5iilfc«Ii^in«Slj^ff;>^^ 
 
m 
 
 OPHTHALMOSCOPY OF THE FUNDUS IN LIVING BIRDS 
 
 37 
 
 FiR. H. 
 Nubian Ostrich {.:itruthio camelua). 
 
 Pig. 25. 
 American Ostrich {Rhea americana) 
 
 Kig. il. 
 Kini or Apteryx (Apteryz mantetli). 
 
 Fig. 28. 
 Martiiicta Tinamou (Calndromas elegam). 
 
 *"'8««- Fig. 29. 
 
 Westerma..-, Ca^owarj- {Casuariu, occipitalU). BraziUan Scriema {Cariama crutata). 
 
 Diagrams of the Pecten as seen by the Ophthalmoscope in Various Species of Birds. 
 
 
 iii 
 
38 
 
 r,i.r.k-ns „f till- London Zoological society the 
 opiilliMlnioscopic apiK-arances of soverafhun- 
 drcl avian and other eyes. The .letaiU of 
 these fundus views, as revealed l>v the oph- 
 thalmoscope in many species, are described 
 and dt7)icteu in Chapter X an.l elsewhere. 
 A. The Avian Eyegrnund in General. 
 The average eyeground or fundus oculi of 
 "H.st Day Birds resend.les. as much as anv- 
 thing. the texture „f the so-called "scotch 
 •nixlurcs" in .smooth finished cloth- usuallv 
 light l.rown, gray, gray-blue, blue mi.xe.l with 
 striate rays, or fine concentric marking of 
 ighter gray or white. Scattered over this 
 background are numerous yellowish, yellow- 
 white, brown or gray points of pigment. 
 Although this matter has not yet been satis- 
 factorily determined yet these punctate de- 
 posits are, in part at least, the colore.) oil 
 droplets described in Chapter IV. 
 
 Nocturnal Birds have, almost' in variably 
 yellow-red. orange, orange-red or reddis'h 
 brown fundi, with the choroidal vessels plainly 
 visil)le through tlu. .semitransparent retina 
 >omc of the (Jwls j,resent almost a scarlet 
 vermilion eyeground, and this intensity of 
 colors appears to be peculiar to Strigiformes. 
 tor this reason alone might say with confi- 
 dence that the New Zealand Owl Parrot 
 {Struigop, habroptilus) belongs to this order 
 and not to Psittacif— »s or to Cuculiformes 
 in one of which he is commonly placed 
 
 Ophthalmoscopy of the areas A distinct 
 vision in Uirds supplements the macroscopic 
 and microscopic examination. In many in- 
 stances It affords a better idea of the relations 
 of these area; than does any other means of 
 observation; at least this is true of most avian 
 fundi explored by the writer. As a rule the 
 deep, single fovea and its surrounding macular 
 region are, other conditions being favorable 
 readily observed by means of the mirror, and' 
 their locality, comparative size, component 
 parts, coloration, etc., easily depicted. Con- 
 trariwise, a shallow or organically ill-defined 
 yellow spot" is not so readily made out. 
 Hand-like areas are also better defined by the 
 aid of a magnifying glass and in prepared 
 half-eyes, although in the fundus of the 
 Secretary Bird (Plate XXXI). of the VVhite- 
 
 THE FUNDUS OCULI OF BIRDS 
 
 bellied Sea Eagle (Plate XXXIV) and of a 
 numl>er of other bimacular species the ribbon 
 of tissue IS well shown by the mirror. 
 
 With, ijcrhaps. this exception the macro- 
 scopic description of the area centrales given 
 not only in the Usts of Chievita and Slon.ikcr 
 but m Chapter VII corresponds in a remark- 
 able fashion with the ophthalmoscopic fin.l- 
 ing.s described and depicted in this work. 
 .Nothing has been discovered in this study of 
 the avian fundus by the aid ot the mirror that 
 IS likely to add to or subtract from the classi- 
 fication of the types of central vision sug- 
 gested by the writer in the same Chapter. 
 
 The Pecten and Optic Disc 
 
 Viewed ophthalmo.scopically the avian mar- 
 supium or jH>cten exliibits three fairly definite 
 varieties which may be classified as follows: 
 I. ThoHc pectens whose mass uniformly 
 springs from and equally coters the optic disc 
 ^uch pectinate bodies do not extend into the 
 vitreous cavity farther than the length (often 
 less) of their widest segment, and th.y are 
 sessile on t he face of the papilla. Examples of 
 till , form of pecten are seen in Nyeticorax 
 nyeUcorax (Pig. 45). Halimua Uucoccphalus 
 (I'lg. ..()), Caprimulgus europeus (Fig. Co) 
 Strixflammea (Fig. 59), Serpentarius (Fig 52)' 
 Struthio camclus (Fig. 24), Canctoma cochle- 
 ana (Fig. 46). Casuarius occipitalis (Fig 26) 
 Spheniscus demersu» (Fig. 37). Tinnunculu's 
 alaudanus (fig. 55). Calodrmnas eUgans (Fig 
 28) and Symium aluco (Fig. 58). This method 
 of arranging the pectinate tissues makes pro- 
 vision for a blood reservoir large enough to 
 supply nutritional needs but so placed that it 
 docs not materially obstruct visual or light 
 rays. Such a disposition and configuration 
 "f the fundal organs meet the needs of many 
 species, among them Eagles and Owls, wh-. 
 re(|uire (and have) very acute vision. 
 
 II. Some pectens, while they originate from 
 the whole surface of the optic disc, immediately 
 slope away from the visual axis, approach the 
 bulbar wall and terminate without projecting 
 far into the vitreous. In this type there is 
 generally a disc-length or more between the 
 free terminal of the pecten and the posterior 
 surface of the crystalline lens. 
 
OPHTHALMOSCOPY OF THE FUNDUS IX LIVING BIRDS 
 
 3» 
 
 FiK. 30. 
 Ilarlecjuin Quail {Coliirnix hutrionica) . 
 
 Fig. S8. 
 Common Wood Pigeon (Columba palumbiu). 
 
 Fig. 31. 
 Brush Turkey {Catheturua laihami). 
 
 Fig. 34. 
 Victoria Crowned Pigeon {Goura vidoria). 
 
 fig- 3«. Fig. 35. 
 
 Yarrell's Curassow (Crax globoaa). Wonga Wonga Dove {iMcotarcia picata). 
 
 Diagrams of the Pecten as seen by the Ophthalmoscope in Various Species of Birds. 
 
 it i| 
 
 ■'1 : 
 
40 
 
 THE FUNDUS OCULI OF BIHDS 
 
 Fig. 36. 
 Ipwahn Rail (Aramidet ipeeaha). 
 
 Fig. 87. 
 Black-footed Penguin {Sphenucu, demtrnu). 
 
 Fig. SO, 
 Herring (Jull (Lariu argentaliu). 
 
 Fig. 40. 
 Great Black-backed Gull (Lanu maHnu,). 
 
 Fig. 38. 
 Puffin {Fratercula arctiea). 
 
 Diagra,ns of the Pecten as seen by the Ophthalmo«:ope in Various 3pede, of Bird,, 
 
 Fig. 41. 
 Stone Plover (Qedicnemiu acolopax). 
 
 
OPIITFIALMOSCOPY OF THE FUNDUS J.\ MVIN'(; HIRDS 41 
 
 Fi«. *i. 
 Little Bustard (Telrax teirax). 
 
 Fig. 48. 
 Kagi i Rhinochetui jubalui). 
 
 Fig. 15. 
 iNiglit Hrruii (S'ycticorax tiyeticorax). 
 
 Fig. 46. 
 Boat-billed Night-Heron {Cancroma cochltaria). 
 
 Fig. 44. Fig. 47. 
 
 European Bittern (Boiaum tUllarit). American Jabiru {Mycteria americana). 
 
 Diagrams of the Pecten as seen by the Ophthalmoscope in Various Species of Birds. 
 
 ■tri 
 
 n.3*.-"w."w-7;y 
 
 'Ldia:.x^Hiu«:!i'i3»<«i;i;:iaBKrtGSb:.j2:wiBcr^u.<j>i; 
 
 ^!xsiSi.;r^'Mi7^ji^'^,i-^'ix;: 
 
4« 
 
 THK FUNDUS OCVLl OF BIRDS 
 
 Fig. 48. 
 Blue Snow Goose ^C'lun caruluetm). 
 
 Kig. 49. 
 
 Red-bUled Tree Duck (Dendroeygna autumnalu 
 ducolor). 
 
 Pig. il. 
 Cormorant (Phalaeroeorax eatho). 
 
 Fig. M. 
 Secretarj- Bird {Serpentariut crUtatui). 
 
 Fig. 50. ... 
 
 Fig. 53, 
 Gannet (Sula bai'MM). .„ . ,„ 
 
 Lttmmergeier (GypaHtut barbatui). 
 
 Diagrams of the Peoten as seen by the Ophthalmoscope in Various Species of Birds. 
 
OPHTHALMOSrOPY OF TIIK FirXDrs I\ MVINT. BIRDS 
 
 Fi({. 54. 
 Whitr-bf llinl S«'B Kagle (Haliattiu Ifui-ogaMer). 
 
 Fig. 17. 
 Rurmwing Owl (Speoiyio eunieularia). 
 
 Fig. 55. 
 Common Kestrel {Tinnunculut ulaudariut). 
 
 Pig. iS. 
 Tawny Owl (Symium alueo). 
 
 Fig. SO. Fig. 59. 
 
 Americim Bald Eagle {Haliattiu leucoeephalxu) . British Scrcech-Owl (Strix flammea). 
 
 Diagrams of the Pecten as seen by the Ophthalmoscope in Various Species of Birds. 
 
 m 
 
 'SI 
 
44 
 
 Mm. fimU rx«,„,,| f ,hi, torn, in Cnl^ml.,, 
 
 I»ih,mh,uil-,K. 33).r,„„/„,,,,«„r„., ,Fi., ,w 
 CnthHur,,, ln,h.mi , F.„. ;„ , ,„ru, „rgr,„„,u], 
 (l-i«. 39). A. m„rin>i^ ^V^lt- M)u KhimHh.i,,., 
 Main. ihiuiSi. (iouru r„l.,ri., (FiK.'J*) 
 < h,„ crrul.,,;,,. ,K,„. 4H,. .»/^,,,„« a„„.r/,«,»i 
 (fix- »7i. SiHoljil,, n,„in,l,iri,i fFi«57i 
 SInngnp, h„l,rn,,til„, i Kjj,, ,|<,. r/,„^,„,;; 
 
 «»»/;»«,. ,ri«. «(i). niin, „„„rw„„., ,F,„ i,„ 
 
 •V//.. hn....,,,,,, (|',„, .«),. //„//„,,/„., k,r.,y,„l,r 
 <H« -IK. Trnvi/,,,, ;/„/,n/«i (Fi«. HI). Dm- 
 ilriiiiui „iil,im„ali.* di.icolnr (Fit. \{)) (rax 
 ffh'l'n,,, (Fit'. .'Wi, Frahmila „r.;ir,i (Fi'k 38) 
 M/<v/„ ,/,;/„,, iFitf. 0.1). ,„„| flolann,. ../.Ilanl 
 IriK. 4i). 
 
 III. T/n: ,./„..,, /„./„,/,,, ,/,„,,, ^„,.,,.,^, ,^^,^^_ 
 nll,,„f,l,n,l.r ,m,,„,rti,„t^) llml „ri,e from Ihr 
 "hole .urM'r „f ,!„■ npiir ,>„,,ill., niul, Ihn, 
 '■>//,. r mm- l,„r,mh „n,l fnllnu- th,- cmrmr .rail 
 ••J Ih. n„hall or th.,! prornd l„ „ ..traiyhhr 
 hn, „„hl Ihey Umch ior „r„rly r.;,rh) th,- p,,,!,- 
 nor .urjmr of Ihv /,„.. ,,n„n,ll„ ,„„r it, 
 "I'K'lor |„ „„.,, in>,a„,.,.-. IImt.- is Irvs than 
 ■'-I.- l..nKt I, l,..| »..,-„ 1 1,.. ,«.,„.„ ,,.„„i„„|,„„, 
 llx- .-MS rai.Mil,.. T.. tlii, ,.|a.H.s l„.I,m^' ll„. 
 |wft. ns .)f llinnido nislini (Fijf 71) / r„ 
 '■".v,v./„ ,„;■,,,„ (Kij,. .,.5). (■,„„„„,,;,„ rervc'olor 
 *!•.„'. 7.J). Munu. poh,,jl.,lto. ^Fi«, 7i). .s>,„,„. 
 Uuxadratu. ,Fi«.04,. .V„«,/,„r„ ,.y,„„„,V,„ 
 1 1- IK. 7^5). .iramid... />■,•,/',„( Fii:. ;l«), .l/./,TV.r 
 '';',"""//' <Fi„. 47. ami Col.rnU histrio.nn, 
 
 Th."„- arc many s,„., i,-s v.ho.s,. in^ctcns 
 ••••fipy a position intrrnicliat,. t„.lw,.,.M 
 <l.-.ssn.,n,l(|assJII, an,l«l„VI, ar,.,.oMs,.- 
 'l•K■»tly. not .asy ,o piac... <)ftlios,.thatar.- 
 f>K«n..l m tl„. text may 1... .n.-ntion.-.l Rhnm. 
 phutn.hwmafu. (Fi^. ti7). OH, tetrax (FiK 4«) 
 JMocopu., major (Fig. 68), rhalacrocor,u 
 rnrho (t,f,. 51 ). rv.r,./., ror«r ( Fiff. 7B), rv„/»r»v 
 ><ym,li.-< (FiK. 09). Pllan,m,hrl.;„„„. ( Fi« 
 <0) and < iiridma rrisfa/ii (Fi'.'. 2."}) 
 ^V<7//,. „.m-y?/.r,..v. .\s previously stat.-.l 
 the neurilenm.a. „r nervr-shoath.' of the 
 optiens is in many Uir.ls, a.s .K.asionallv in 
 Alan, eont,nu...l info the retinal snl.stanee 
 These nerve-fil.res are easily seen in the avian 
 fundus u^en v.ewe.l with the ophthahno- 
 scope althouRh ,n preserved eyeballs thev /.re 
 invisible to the naked eve. 
 
 TIIK niNDirs 0< ILr OF HIHDS 
 
 !•• M.n.e .MManee, they radiate from the 
 iM-rve-hea,! a, whili.h. thrt-ad-like ravs in 
 xUi U a f,„|„„„ ,„ ,„ ,.„^.,.^ ,,_^, ^|^^|- ^^^ ^^ 
 
 wule ar.a nhout the optie enlranre. This 
 eon. I.l.on is „,.|l shown in T„r,l„. n,.r„l„ 
 x'\u '"V"- ■V"!/../..*.* Wr«/„., ,|.|a,,. 
 .\I.IUI, KhamphiiMiiD IitiikiIi,^ (I'Inle XI VI) 
 I'l'ijmti, Mn,„ll,„ (IMate XXIII). and V.,/- 
 niiUfHluH aliituliiriiiM i Plate XXXVi. 
 
 A-. a rule, however, the i.vianVund.is i, fr.e 
 ;, "'".'*■ '"/'■'■ '•'••"■ents; in all prol.al.ilil v 
 th.-y mfrfere to son.e sli„ht extent will, 
 K'Meral retinal vision an.l are ,on>e.,„enllv 
 al.sent in those Keiiera re,|uiri,iK the most 
 :""'*■ ^•'=""' l'"«'-r^- They are few in num- 
 l«>r or are entirely al.sent ii. .\i„hi Mirds. and 
 m sneh repreM.ntative s,M.<.ies as <;,,„„/„,, 
 WW,,., , Mate), XXXn r.,.uarn.. orrU,i. 
 1 1 late nil. Il„h,ul„. l,„c,H-rph„h,.. (|'lale 
 XXXIII) and lihiuorhitu^ j„hnlu. (|«late 
 
 They are short or inroiispiViiens i,, .ill ih,. 
 |.earim.te l.irds, so far examined, inelu.lin« 
 Ih.- rinamou (Plate V) as well as in 
 ^yrl,corar mp-llcorox (IMate XX), Crox „/,.- 
 
 Vn, .";;/,"• ^'""-"'> /"■"">""•'•" (I'iate 
 * III 1 -iniil haliwrorornxcnrho ( I'late \XVM| ). 
 
 E. Photography of the Fundus Oculi in 
 Living Birds 
 
 Mmi.v attempts have I.een mad., to photo- 
 graph th,' f,„„l„, ocli throu,jh the pupil i„ 
 l»-ing sul,j,.<.ts -to eombine, as i| u.r,. 
 ph..toKraj)liy with ophthalmoseopv. If t|,is 
 •sehenu. IS ever put into pr.icH.al 'operation, 
 t-s|M.emlly If It l.e fo„nd possible to ph.,t.,«ra,,li 
 ta- eyeKroiin.1 in its natural colors so that 
 th.- negative .-an b,. repr.jdue.-.l and ,>iib|ish,.d 
 a K'n-at advance will l,c made over th.- r.-' 
 .stricte,! (lH.,.,„ise slow and expensive) plan 
 p.r force n.lopted by the writer. I'hotoir- 
 raph.v of the colorcl .lefails of the fim.lus 
 W..UM render unnecessary either th,- ex,,ert 
 ophthalmologist or the trained artist, while 
 he number of avian l.ackKroun.ls exnlor,-d 
 by such exact methcJs woul.l s,.on be count,-<l 
 by .undreds where they are now retfistercl b^• 
 units. Moreover, a.s the ophthalmom.pi'c 
 picture IS to a certain extent .lifTerentlv inter- 
 preted, and correspondingly described and 
 
 ^\\'>'^^^t«JSStS«F?/'7CliS:^.- i-i** '""i^f 
 
 ^•3.::'''"i:«^?Lrtr^:,.^::^ir/«rj^iia^^ 
 
<)PIITIIAI,M()S("()I»Y OF TIIK Kl'NDI'fi t\ 11\IS<, lUKHS 
 
 «• 
 
 V'\H. (Ml. 
 Amunii PmtuI (CArywrfu omajoniVa). 
 
 Viii. e». 
 
 Kiff. 61. 
 Lcner Sulphur-rrestrd Cockatoo (Variaua gaieriia). 
 
 FiK. 64. 
 Block Hornbill {SpagnUiinui iidruliii). 
 
 fig- 6«' Fig. 6.5. 
 
 Kskspo or Owl Parrot (Stringopt habropHltu) . Nightjar {C,, primulgui 'ur„,,e„^). 
 
 Diagranu of the Pecten *i seen by the OphtbalmoKope in Various Species of Birds 
 
 ^5?SS!!^B?!^!?^yS 
 
 i. 
 
46 
 
 THE FUNDUS OCULI OF BIRDS 
 
 Fig. 6«. 
 European Cuckoo (Cunlut canoru^). 
 
 Rg. 67. 
 Sulphur-b««ted Toucan («Aam;,Aa^« Z,^, 
 
 'tu). 
 
 Fig. 68. 
 Great Spotted Woodpecker (Dend, 
 
 roeoptu major) 
 Diagrams of the Pecten 
 
 Fig. 89. 
 Gila Woodpecker \Cen,uru, (Melanerpes) uropy^U]. 
 
 Pig. 70. 
 Derby TjTant (PUangw, derbianut). 
 
 Fig. 71. 
 Chimney Swallow {Birundo rurticn) 
 -n by the Ophthalmoscope in Various Specie, of BiHs. 
 
f 
 
 OPHTHALMOSCOPY OF THE FUNDUS IN LIVING BIRDS 
 
 47 
 
 Fig. 7«. 
 American Mocking Bird (Jtfimiw pnlyglottos). 
 
 Fig. 74. 
 Blue Jay (CyanociOa cristata). 
 
 Fig. 78. 
 American Bunting (Cyanospiza rerticalor). 
 
 a 
 3 
 
 Fig- '''■*• Fig. 76. 
 
 Law Bird of Paradise {Parotia lawit). European Raven (Conus eorax). 
 
 Diagrams of tlie Pecten as seen by the Ophthalmoscope in Various Species of Birds. 
 
48 
 
 F)i<turo,l hy different ol.servers, un aocurnte 
 photographi,. reproduction i. nuich to 1„. 
 di'sirod. 
 
 rrol.al.ly tl,e inv,.nl,.r who lias cnie nenr- 
 «-st this ideal is W„l(f tMonahhI. f. Augen- 
 linlL, p. 447, Oct., Xov.. 1907) of Berlin, 
 who has done niu.li in the photo^raphv of the 
 human fundus. II,. „,,„i,. „„, „f ,,;,. |j^,,,j 
 furnished I.y the Z.iss projection apparatus, 
 the etferent rays i.eini; reflected into the eve 
 IIirouRh half the puj.!!, l,y „ s,H-ciallv con- 
 trive.1 .Mirror. The efferent rays pas.s;.,! ,.ut 
 thn.uKh the ,.lher half of the puj.il and were 
 foc'usse.! in a photographic canuTa A circh- 
 of the fundus al.out 10 mm. is thus illuminated 
 at cue tune and the resulting picture— of 
 c..urse in Rra.v- tones - is magnified fn.m thr ■ 
 to four dianulers. The re<,uired exi„.sure is 
 less than one-thirtieth of a second. The prints 
 showed the optic entrance, the retinal vessels 
 
 THE FUNDUS OCULI OF BIRDS 
 
 and other gross .letails of tlie eye-groun<l but 
 lacked that .lefinition without which fundus 
 reproductions are of little practical value. 
 
 Niimilaled I.y these experiments of Wolff 
 ai'd by the experience of Dimmer, Thorner 
 ami Xeiihaiis, the writer, in conjunction with 
 l^r. tarl Brown of Chicago and other exp.-rls 
 has endeavored to s,.lve the problem botli ..f 
 onhnary and chronio-photography of the 
 avian fundus. It must be confessed that 
 nothing .satisfactory has come of these efforts, 
 nor of th<' corresponding attempts, referr.>d' 
 l<> on p. 61, to photograph the eveground of 
 prepared specimen.s. The main difficulty 
 (without entering into the details of the fail- 
 ures) in all the.se instances lies in the present 
 impossibility of focussing clearly at the same 
 instant all the points on such a concavitv as 
 the interior of the eyeball presents, either 
 in Its pn.1t mortem or its living state. 
 
Chapter VII 
 
 MACROSCOPIC APPEARANCES OF THE FUNDUS OCULI OF 
 BIRDS IN PREPARED SPECLMENS 
 
 This .sul)jcft lias to some extent been dis- 
 cussed in Chapters IV and IX. As previous- 
 ly stated, the actual appearance, arrangement 
 and relations of the organs in the Hird's 
 fundus — pecten, retina, optic nerve, choroi<l 
 and choroidal bloodvessels, macular regions 
 (areas of distinct vision) — can be readily i)er- 
 ceived in properly |)reserved eyeballs. Im- 
 mersed in Perenyi's (Itiid and a series of 
 alcohols and otherwise carefully j)repared, an 
 equatorial section of an avian globe furnishes 
 material for a satisfactory macroscopic study 
 of many of the parts in the interior of the eye. 
 The gross relations of these i)arts in typical 
 birds are seen in Figs. 1, 5, 0, 7, and 11. 
 
 The Pecten is probably always somewhat 
 shrunken and more or less displaced even in 
 the freshest and best i)reserved spec'iniens; 
 so that allowance must be made (in examining 
 prepared material) for that fact. This is the 
 reason, perhaps, that Aptcryx was for several 
 generations credited with absence of a pecten, 
 until Lindsay Johnson proved its presence in 
 that bird. The peculiar construction of the 
 small marsupium in the Kiwi not only made 
 it easy of reduction in volume but it was also 
 decidedly bleached by the alcohol in which the 
 (old) material was inmiersed for a long period 
 before it was made the subject of that naked- 
 eye examination that led to the original 
 error of observation. 
 
 The i)ecten varies in shape and size, as well 
 as in the number and the character of the 
 folds of ti.ssue that compose it, according to 
 the genus' to which the bird belongs. Indeed, 
 such a striking and varied picture does the 
 pecten exhibit, both when seen with the oph- 
 thalmoscope during life and in prepared niac- 
 
 ro.scopical and microscopical specimens after 
 death, that one might almost recognize the spe- 
 cies by studying this organ and its relations to 
 oilier parts of a biril's fuiulus. In the accom- 
 panying text are a number of drawings of the 
 avian jHrten as seen in prepared eyeballs. 
 
 That the human liyahUI arlcnj oj fetal life 
 
 a vcstigal [X'cten .seems almost self-evident. 
 N'o one who has examined a persistent hyaloid 
 artery and its branches, particularly if he has 
 been fortunate enough to see the vessels 
 carrying blood to and from their termination 
 in the vitreous, can fail to be reminded of the 
 structures that occur normally in some mam- 
 malian, most reptilian, and all avian eyes. 
 This arrangement surely carries us back in 
 fetal evolution to tho.se sauropsidian ances- 
 tors who have left their mark on our cm- 
 bryology. 
 
 .Attention may be especially drawn to the 
 pecten of the American Coot (Fulica ameri- 
 cana). consisting of 15 double folds. It shows 
 in a remarkable and unusual fashion their 
 fan-like arrangement, especially at the free, 
 upper margin of the organ; it is there firmly 
 attached to the fine vitreous proces.ses and 
 the hyaloid membrane. See Fig. 84. 
 
 In (Jadow's contribution to Bronn's Tier- 
 Reich a list of the number of convolutions in 
 certain Birds is given, and reference is made 
 to an attempted classification of Aves based 
 upon it. 
 
 The op/i'c disc, viewed macroseopically, is 
 generally seen as an oval, ovoid, sometimes 
 almost round, white or yellowish-white area 
 largely ob.scured by its union with the base of 
 the pecten. Its long diameter is generally 
 from two to three times its width. 
 
 [40] 
 
 
 ii 
 
50 
 
 THE FUNDUS OCULI OF BIRDS 
 
 Fig. 77. 
 
 Nubian Ostrich 
 (Struthio canulut) XS. 
 
 Fig. 78. 
 
 ^rn^t.ineU Tinamou 
 (Rhyru noiiu rufetceru) x 10. 
 
 Fig. 80. *---.,__ 
 
 British Wood Pigeon (CAumba palumhus) xlO. 
 
 Fig. 81. 
 Wonga Wonga Dove (Leucoiarcia pwala) x 10. 
 
 Fig. 79. -., 
 
 Valley Partridge or Quail (l^HoHy. californicu. Fig. 82 
 
 rallicola) xl6. . 
 
 Pigeon GuiUemot (Cepphus columba) X9 
 Wa, View of the Pecten in the P^pared Eyes o, Certain Species of Birds. 
 
 *" m- irr ii K ^^ 
 
 Mwvt-ir* 
 
 i..*'.w . i'l: 
 
 •fsr.TSrif 
 
 »f3!^»^^!CI 
 
FUNDUS OCULI OF BIRDS IN PREPARED SPECIMENS 
 
 51 
 
 3 
 
 Fig. 83. 
 European Crested Grebe (Podicipei eruUUiu) X 12. 
 
 Fig. 84. 
 American Coot (Fulica americana) Xli. 
 
 Fig. 85. 
 Dark-bodies Shear-water (Pt^ffiniu griteua) X9. 
 
 Fig. 8a. 
 Herring GuU {Lanu argentalut) x7.5. 
 
 Fig. 87. 
 Greater Yellow Legs (Totanua melanoleuciu) XU. 
 
 Fig. 88. 
 Hudsonian Curlew {Xumeniut hudsonietu) X 18. 
 
 Lateral View of the Fecten in the Prepared Eyes of Certain Species of Birds. 
 
 
59 
 
 THE FUNDUS OCULI OF BIRDS 
 
 FiR. <H. 
 
 BI«ck-cro«-„e<l Night Heron (Xyeticorax nyclicorax 
 nceriua) xO. 
 
 Fig. 80. 
 Black-bellied Plover (Squatarola ijuatarola) X9. 
 
 Fig. 90. 
 Great Bustard (0/w tarda) XS}^. 
 
 Fig. 91. 
 American Bittern (Biiaurui lentiginosu,) x8. 
 
 Fig. 9S. 
 lesser Snow Gooae {Chen hyperboreiu) x9. 
 
 Fig. 94. 
 
 Common (Old World) Flamingo (PhomkopUrxu 
 roteiu) X8. 
 
 Uteral View of the Pecten in the Prepared Eye. of Certain Species of Birds. 
 
 ^ssaK^cji ».'mraKvr.«xisr7BiBui'aFHK:^ 
 
FUNDUS OCULI OF BIRDS IN PREPARED SPECIMENS 
 
 58 
 
 i 
 
 Fi)?. 9j. 
 Brandt Cormorant {PhalacrHcorax pfnicUlatita) X9. 
 
 Fig. 96. 
 Tawny Owl (,S\fmium allien) x7. 
 
 Fig. 97. 
 European Bam Owl (Strix flammta) X9. 
 
 Fig. 98. 
 
 Greater Sulpliur-tresled 
 Cockatoo {Cacatua gederila) X9. 
 
 Common (British) Kingfisher 
 {Alcedo upida) X 18. 
 
 Fig. 100. 
 Common Hoopoe (Upupa epopn). 
 
 Lateral View of the Pecten in the Prepared Eyes of Certain Species of Birds. 
 
«4 
 
 THE FUNDUS OCUU OF BIRDS 
 
 Pig. 101. 
 Anna Hummingbird (Cciypu anna) X81. 
 
 Fig. loi. '- ..^ 
 
 Yellow-billed Cuckoo 
 (Coeeyzut americaniu) x 18. 
 
 Fig. 103. 
 Red-headed Woodpecker (Melanerpe. erytk^;,^, 
 
 -). 
 
 Mr. 104. 
 Hcd-shafted Flicker (ColapUi 
 
 meruaniu). 
 
 Fig. 105. 
 Western Mockingbird (ifm„ poly,u>Uo, UucopUru.). 
 
 Uteral View of the Pecten in the Prepared Eyes of 
 
 Fig. 106. 
 Bluebird (Sia/ta rialU) X18. 
 Certain Spedea of Birds. 
 
Fiff. 107. 
 California Shrike (Laniua ludotieianut gambeli). 
 
 FUNDUS OCULI OF BIHDS I\ PREPARED SPECIMENS 55 
 
 The Retina iiiiii the towels nj the chormd are 
 prncticftlly invisible in the ,.yes of birds viewed 
 niHcroscopicttlly a few minutes after death. 
 However, when treated with Pcrenyi's fluid 
 and otlier preservatives or espeeially in ease of 
 sueressful carotid injections, the <horoi(hd 
 bhiodvesseis and tissues beeoiae more opaijue 
 or at least more translucent and may then be 
 studied with success. Doubtless the upli- 
 flialmoseope gives us the one U-sl means of 
 seeing these tissues as they exist during life, 
 but both methods, supplemented by the mi- 
 croscope, arc needed for a complete study of 
 them in all their relation.^. Very little light is 
 thrown on these (juestions by naked-eye ob- 
 servations of the choroidal vessels, although in 
 some birds, esiwcially when injections of car- 
 mine have lieen mnde, they are quite evitient. 
 Serial sections, in conjunction with the use of 
 the ophthalmoscope, afford the best means 
 of studying these fundal vessels. 
 
 The pigment deposits and other histological 
 elements in the choroid and retina — espe- 
 cially in the former — that combine to nuike 
 or modify the general coloration of the fundus 
 oculi are best seen with the ophthalmoscoix-; 
 prepared specimens furnish but slight indi- 
 cations of these. Differences of level, as in 
 ■■•cular areas, are, however, well shown 
 niacin. ^„^Ically. 
 
 Areas of Distinct Vision. As a result of 
 t le investigations of Slonaker and the writer 
 i may be said of Birds with but a single 
 i jvea that this sensitive area is gen-^ rally 
 :^laced about the center of the retina, slightly 
 above and towards the nasal aspect of the 
 optic nerve entrance. This observation is 
 practically illustrated in a number of pictures 
 reproduced in this work from the drawings of 
 Kennedy and the paintings of Head. See, 
 for example, the drawings of the fundus views 
 o{ Sialia sialis (Fig. 140), Conus americuniis 
 (Fig. 142) and Nycticorax nycticonix (Fig. 129), 
 in which a single, deep, well-defined fovea is 
 present. 
 
 An exception to the rule of the nasal posi- 
 tion of the single fovea? and macular regions is 
 noticeable in the Owls. These birds possess 
 a single, deep fovea encircled by a round, 
 sharply defined area located above and on 
 
 Fig. lOH. 
 Ameriran Crow (Comu americaniu) . 
 
 Fig. 109. 
 Steller Jay {Cyanocitta lUUeri) x U. 
 
 Lateral View of the Pecten in the Prepared Eyes of 
 Certain Species of Birds. 
 
S6 
 
 II..- Innporal si.lo „f tlu- optic- .ii«.. „„ e,„,„„,.. 
 .. whul. M ,„,.,. ,r...l i„ .s>«,«,„ nluro (hL. 
 Ui) Hii.l .s/r,j- Jlammi;, {Vig. Hi) Tlii» ,," 
 rm.«,M„„| d.,^.lv „,,,,r„„,.,„,, „„. ,,i,„,,„|,,^ 
 •"."M. ..• of M.„; i,,.,.,.,, „,.. ,.,„,,, „^,.„,^ 
 <'f Mr.«.f..rnu-s r,-s.-,nl,l..s th,- hun».„ .-vi- 
 ""-■;'• <I..mI.v tlmn ,lo.-s any ..ih.-r ..r.l.r ' 
 
 II..- rW»,V/ i. Ht-en ...M.r.,s,..,,,i,,,||v ,.,H „ 
 'lark l.a,ktfr..un.| for tl,.- In.n.li,c,.„t, or oi.lv 
 PHrlm y v.Ml,|..r..(i„„:i„,l..,..|. ,l.,.,,„|„r,„i„;, 
 
 |.ic-l,..-,-s .,f tl... l.inj-, f,„„,y, .^ ,,,^^^,,^. ^,^,||^ 
 '■"•"•.I l.v this .k-eply piK„,,„i,.,l o^.tar t„„i.. 
 with .Is rich vascular supply. 
 
 Ax notcl i„ nuxptvr Vill. domotivaU,,,, 
 l.n..Ks about diaiiKos in <.ll the fun.lal tiss.„.s 
 •iNWally tissue .l.-Kc..,.ration. if not actual 
 <l.«.'as.-. Hen... «e 6n.l that (iailin* pos.s«..s.s 
 very shallow or .loiihtful f.,ven-. The writer 
 has coiieer..e.i hiu.s«-!f lillh- with Imrnvar.l 
 fowls hut Slonaker has shown that whi!.- 
 f olumlm l,nu domcMica, still r.-tains a n.,.,liu,i. 
 fovea surrounded l.y „ w,-l|..iefiu,.,l macular 
 >irva Mvlaujn, galloparo ..n.l Xumida pmlur- 
 on, hav.. very shallow area- ceulraU:. As 
 state,! elsewhere. s.,„.e Birds have no macular 
 n-Kion demonst rable by t \w naked ev.-. lUdlu.', 
 domesneu. U example, has an 'extremely 
 doubt ul „v,.a. while Anscr donu,tiru. an.l 
 Anai boxchas donuMicus, in a.ldition to a very 
 shallow macular region, exhibit a band-like 
 area extending horizontally across the retina. 
 Ihe hitter device probably enables the bird 
 to w.don the hmits of his fiel.l of distinct 
 vision (especially while feeding) without being 
 "I'hged to move the whole head. This c.iri 
 ous provision is mo«. clearly shown in the 
 Iting-.Nec-k Plover who.se fundus shows a 
 very distinct band-like area that passes 
 obliquely acros.s the retina. A dark line 
 I'ke a trough or gutter, appears to the nake.l 
 eye ... preserve.1 specimens to exten.i abnost 
 the full length of the band. Sl.>nake x- 
 nnned thi.s area microscopically but could tind 
 no trough-hke depression. 
 
 Oval, ovoid, circular or ribbon-like areas 
 are as a rule, readily traced in the gray' 
 smooth retinal tissues, although both the 
 microscope and ophthalmoscopt- may be 
 needed, as i„ the Flamingo and some of the 
 
 THE FUNDI. (K ULI OF IHHDS 
 
 t.olhnaceous bir.ls. a.s a suppl.-m.-nt to macro- 
 Mopic .„.,,H..iion to ,Wi.|,. th.- pr.„.„,.,. or 
 otlier«,«- of u ma.ular region or of ai.v of 
 ■ ts con.,H.n..nts. Tl..- lin.its of H... n,i,nd 
 'wm/ ,,„.„ often call f..r th.-se aids; in.|.....l it 
 -na.v be sa..l that m. exph.rali.m of an avian 
 fun. his shouM be r,,^„r,|,.,, „, ,,,„„,,,,.,,. ,^^^,., 
 
 "II th.-se r.-.|uirements are met. .\reas of 
 acute v.sion. in pr.pan-,1 material. app,.ar I., 
 Ik- whit.-r ..r l.-ss gray than i!,.- surronn.ling 
 retina; th.-r.- is i.ot, h.nvever. a ^harp .IcKni- 
 "'" 1" ll.e nake.1 .-y... or even wh.n ..bs.-rve.l 
 l-.v II..- h.-lp .,f a magnifying hns. but the tis- 
 SU.-S of th,- «r.«. c-ntraUs sha.h- olf an,l grn,h.. 
 ally 1)1.-11,1 with lu.- i)erinia,iilar tissues. 
 
 It must not Ih- assum,-,! that becaiis,- ,„. 
 "-ntral area of .listinct vision is ,li.scover.-.| 
 macr,)sc,)pically that it .hx-s n.)t exist. .So.ne 
 ".acular r,-gions are so shallow an.l so slightly 
 <htr.-rentiat.-,l from the neighboring tissues 
 tliat ,)i.ly the microseojH> can settle the .lues- 
 tion of their .-xistence. 
 
 The .-xacl character an.l visual purpose of 
 these retinal ban.l-like areas (sonietim.-s also 
 visib e to th.- ..phthalmoscojH.) await further 
 histological imestigation. 
 
 Birds of pr.-y as w,-ll as the swift iliers show 
 the best mark,-,l aii,l th,- gr,-al,..,t variety of 
 "'aciilr r,.gioiis. A ty,,ical instan.v Is m-,-,, 
 m the Sparrow Hawk. In this h each 
 fumlus presents a wel)-n.arked for- ^mlu 
 and Jmtu Umpnralii, connected bv . short 
 band-like iirea. 
 
 Tl .. naml fovea is invariably the d.-eper an,l 
 sharjM-r ,if the two. and probably is us.-.l when 
 •lisunct sight and i.intx-uhr vision ar- require,! 
 It i.s surroundcl by a large, macular an-a au,l 
 IS situated about the cent,-r of the retina. 
 
 Ihe temporal Jorea h shallower, is encircl,-,l 
 I'.v smaller area and is placed near Ihe 
 IK-nphery of the retina lower than the nasal 
 fovea but about the same distance from Ihe 
 optic papilla. This foveal region hohls about 
 the same r,-lativc position in the fundus as 
 the .smgle fovea of the Owl while the fovea 
 nwiaiis stands i.. the same relation as that 
 occupied by the Blue-Bird and the I{obin 
 
 Of the swift fliers the Terns and the Swnl- 
 ows present much the same foveal and ban.l- 
 hke sensitive regions as the Hawks; in other 
 
FUNDUS iKVLl OF BIRDS I\ PREPARED SPECIMENS 
 
 47 
 
 Fig. 1 10. Example of the First Type of Central VUual Area- in Birds, The Amacular Fundus of the 
 Califurnia \'alley Quail (Lophortur californiciu vallicola) X 18. 
 
 m 
 
 Fig. 111. Example of the Second Type of Central Visual /Vre« in Birds. The Nasal Monomacular 
 Funduj of the Steller Jay {CyanocUta lUUeri) x 1«. 
 
48 
 
 THE Fvsms ornj of birds 
 
 KiKlW ^'-^ '•"f.lHThir,ITy,..„f<V,,,ralVisuulAr..«.i„I,irds Th. T 
 
 Fundu, of the K,,.,,.... „,,., o,, t^^lS^.J^J"'"'"' ' 
 
 Monomacular 
 
 RgllS. K'-n-Ple of the Fourth Type of Central Visual Are» in Bird. Th, «• , ^ 
 
 the British King&her (A^i^;!'^' ^' ^"^"'" ^^'1'" "' 
 
 'i^ 
 
Frxni s (Hvu UK niKDs in prkpared spe( [mens 
 
 worda the diiipoititiim of the nr«iis for Bcutr 
 vUion n»niinn'< this furin in Hir<N ilial likt- 
 fb«'ir pn-y on Ihr win« or l.y (liirtiii« upon il 
 fn)ni a diiituncc. 
 
 A Clauiflcation of Areas of Distinct Vision 
 in Birds 
 From tlu' forcKoiiijj ii nmy !«• coticliiili'il 
 that then- an- at least six nrritnutinents of 
 these nnvM, ntid ron«'<|iiiritly six forni>i of 
 appiii-iiliM for senirinn ihhIi' < y. si^hi in l.irds. 
 IVm- may lie clan-tified as follows: 
 
 I. The amariilar fiDidii.i, in which, as in 
 the California Valley (^lail (s<v Fij;. UOi, 
 there is to !>.■ s«H'n neither with the ophtliiil- 
 inoseoiH- nor in pn-served material any iniliea- 
 tion of a eentral niaeidar region i rather a rare 
 cittsst. It is only 1 v a inierosinpical exan ma- 
 tion of serial seeti 'ns that one sees Ih, liis- 
 lolo^ie elements indicative of an area of 
 vision more s|Hrialize<l for ilislinet visualiza- 
 tion than the surroiindinR ntina. Such fundi 
 are rare, and are fontid, for example, in a 
 few domestic birds. Slonaker <liseovered a 
 shallow and ill-define<l eentral area in the 
 Turkey (Mvlaiyrin yullopnro) and the Guinea 
 Ilcn (Sumidiii piirhernni); also "a very 
 sliKl>t thickening," instead of a fovea, in the 
 Cook {(lallim domeatirus), 
 
 8. The naml mniumHindar fundus, situated 
 in the centre of the retina, is found in the 
 majority of birds. An example is shown in a 
 drawiiiffof the eyeground of the Steller Jay (s«-e 
 Fig. 111). A.s a rule, it is best demonstrat' d 
 niHcroscopically, although even a cursory ex- 
 amination of the colortMl plates in this work 
 will reveal numerous examples of this form of 
 fundus when viewed ophthahnoscopically. 
 
 3. The temporal monomundar fundus is 
 found almost exclusively in the Owls. An 
 example of this form is seen in the Euro|Han 
 Barn Owl (Fig. 112); indeed in all the Strigi- 
 fornies whose fundi are pictured or ilescribed 
 in this nionograjjh. 
 
 4. The bimw ular fundus, in which there 
 are two maculse, generally a deeply marked 
 an.l principal na.sal region and a subsidiary 
 temporal area. See Fig. ll.*}, representing a 
 macroscopic view of the (preserved eyeball) 
 fundus of the Belted Kingfisher. 
 
 50 
 
 There ri> two Mdivarielies of this fundus; 
 (<l) certain eyes of re^idar form in which the 
 nasal macular rtyiim s well develo|).-d and 
 the fovea is deep .md ^hiirply .lelined, as in 
 Alredi), SIrrnn and Tarhyrinrhi: (b) in bird" 
 with eyes of if egular sha|H'. exhibiting u 
 deeiKT temiurrnl fovea and Iwlter marked 
 macular regi... These are found in llie 
 Hawks espi'ii.ily. 
 
 .'». A liiind-lik,- cnlral arrn with which i:» 
 almost iii\ariat)ly ass(H-iated a w. Il-de(ined 
 fovea or ni.iiul.i. To this form of avian baek- 
 grouiid Hi. writer has given the name i'h/i//(|- 
 murnhtr* fundus. A« an example, sec Fig. 
 1 II, showing a iiiacroscopical view of the eye- 
 ground IN the (Jreiitcr Yellow-legs iTolnuus 
 m<'lnni<lcuiHs). In this < lass the band in- 
 'loses, in some part of its course, the single 
 fovea which in its turn is found on the nasal 
 side of the fundus. 
 
 <i. Finally, in some ;ivian Kackgrounils 
 t her ,ire two macular n [lions, either juiurd Id ,,r 
 assoriaird with the liaud-Uk,- area, to which the 
 name infulaliimaruUir fundus has Keen given 
 by tla- writer. .\n ocular background of this 
 description is seen in the Common Flamingo. 
 See Fig. 1 Iv . There are at least two varieties 
 of this for n. 
 
 The Sparrow Hawk (FdAo sparrerius) and 
 Bull! ■orfalis furnish examples of form (a) — 
 a w ll-cictined nasal macula with a det-p fovea 
 situ; 1.(1 nvar the centre of the rctirui and a 
 shallow liiough easily demonstrable lemporal 
 macula. Hi-' two joined by a -furl ribbon- 
 like are.\. Vl,,. hand area does <n>i extend 
 beyoiii eit'i.T macular region. 
 
 In .secoi; '. :.rm (i), represented by the Tern 
 {Sterna hiii: daK the band-like an'a encloses 
 a nisiil macula while a second (temporal) 
 macular region lies abov. and apart from 
 tlie.se. 
 
 Fven n -light acquaintaiK . .vith the fundi 
 (k'dorum f th^ comparati\.l; few Birds .so 
 far examined ;,iiows not only numerous types 
 of ar.w centrales, but a still greater variety in 
 their size, shape and appc.irance, both mae- 
 roscopical and ophthalinosc(.-)ieal. These are 
 mos- distinctly marked m th. prepared six'ci- 
 mens. Some Birds exhibit .. large, circular 
 'Infula, a band or rilii on. 
 
60 
 
 THE FU>a)US OCULI OF BIRDS 
 
 Fig. 1 14. Example of the Fifth Type of Central Visual .Wa- i„ Bird, The I„f I 
 
 of the Greater Yellow-Ieg, iToU.n7ZZteJ) ^"'"''""-"'" "-d- 
 
 Fig. US. Example of the Sixth Type of Central Vi, 
 
 of the Common Old-woHrFl^So^Tj::.^?'' '"'"''""-"'" ^undu 
 
 I roteut). 
 
^ 
 
 FUNDUS OCULI OF BIRDS IN PREPARED SPECIMENS 
 
 61 
 
 area — single or Jouhlo. sonictinies nssoeiali-d 
 with ii Ijaiiii ari'ii, soniotiiiifs not— with clearly 
 <)utline<l margins antl a deep fovea anil dis- 
 tinct foveola. In otiiers the fovea is shallow 
 and the niaenlar borders arc with iliflionlty 
 differentiated from the fundal retina. 
 
 Photography of the Fundus Oculi in 
 Prepared Eyeballs 
 Attempts similar to those of Wolff and 
 others, mentioned in Chapter VI, to photo- 
 graph the interior of the i>osterior half of the 
 eye hav«' t)een ma<le with some siiceess in the 
 ease of prepared eyes. The difflcnilii's that 
 surround these attempts. althoii<;h fewer than 
 with the living subject, are as yet unsur- 
 mounted so far as minute and e.\act funilal 
 details — the chief object to be attained — 
 are concerned. Pliotography furnishing a 
 clear and sharp definition of small objects 
 arrays ' at various points in one concave sur- 
 face is as yet impossible — hence the blurred 
 apiH-arance of pictur. of the vcrte))rate eye- 
 ground so far publi>..,d. Even the best of 
 these — the enlarged stereoscopic ph'>to- 
 graphs that illustrate Arthur Thomson's 
 Anatomy of the Human Eye (London, 1912), 
 the carefully prepared original photographs 
 in the beautiful atlas of Frit.sch, and the 
 stereographs of Ceorge Dixon — hold out 
 little hope that similar processes may be of 
 use iti depicting avian eyegrounds. Only 
 the laborious pen and brush of the careful 
 and competent artist-ophthalmoscopist can 
 so far be depended upon to depict the mac- 
 
 roscopic appearances of these complicated 
 tissue arrangements. 
 
 R. II. Elliot (The Lancet, p. 830, Nov. 11, 
 1910) has develo|K>d a nu'Uiod of photograph- 
 ing i)repared eye specimens of which the 
 writer has had no (jcrsonal experience, but 
 which he l)elieves may Ix' of value to the 
 investigator. Elliot regards th<- following 
 points of importance: The photograph must 
 be taken in water, without the intervention of 
 glass or other similar material. The source 
 of light must be good and even. The camera 
 nuist be placed vertically above the object 
 so as to avoid reflections. The obji>ct of the 
 photograph nuist be placed so that its image 
 will occupy the center of the plate, and a 
 method of adjustment should be available to 
 .secure this end with a minimum of incon- 
 vcniena*. A simple arrangement is neces- 
 sary to fix the eye in position during the 
 whole period of exposure. To save unneces- 
 sary retouching the object should be photo- 
 graphed lying on a dark and uniform surface 
 to obviate the background disturbing the 
 attention of those viewing the picture. Care 
 should be exercised in the choice of a camera 
 and exposure periods must l)c carefully 
 studied. For the making of lantern-slides 
 the contact method was recomniendetl, and 
 attention was directed to the following points: 
 correct exposure; the preparation of plates 
 for exposure; development and fixation of 
 the slides; the dr,ving of the plates; and the 
 reduction, intensification and varnishing of 
 slides. 
 
 I 
 
 I 
 
Chapter VIli 
 
 EFFECTS OF DOMESTICATION AND OTHER ARVORMat 
 
 INFLUENCES ON THE FUNDUS OCULI OF 
 
 WILD SPECIES OF BIRDS 
 
 As noted ,n Chapter III the eyes of only 
 healthy in.hvi.hials and (as far as couhl l,e 
 ascerlame,!) of normal wil.l siMvies have Invn 
 chosen for the purpos.-s of this research. In 
 praet.ee, however, this is not as easv a task as 
 tirst .-.ppears, s,„ce it is on occasions diffieult 
 to .leei.le l.y „ny or nil of the three principal 
 means of mvestigation - the ophthalmoscope 
 in l.vinf-speeiniens. the microscope and naked 
 eye m preserved globes - whether a given 
 con,htion IS normal or abnormal, congenital 
 or acquired. The writer's observations of 
 he eyes of both domestic and wild birds leads 
 hm. to b,-l,eve that dmnes'icaiion of Birds 
 winch generally means a radical departure 
 from their natural food, exercise, manner of 
 raising their young, use of their various or- 
 gans (eyes ineluded) and above all the effects 
 of confinenjent per se, is the principal cause of 
 lie anomalies seen in the fundi of caged or 
 barnyar.1 species. This difficulty in deter- 
 niimng the exact character of tissue altera- 
 lons IS all the greater when the suspected 
 fundus change occurs in both eyes and the 
 organs are not available for macroscopic and 
 microsco;,.c examination. For instance, the 
 eyeground of the .Spoonbill (Plate XXV) is 
 shown with a curious (and unusual) linear 
 stripe running parallel and clo.se to the optic 
 <;>(•. This may be an abnormal fundus con- 
 dition although the weight of evidence leans 
 tJie other way. 
 
 SnHr.nal bird,, when caged, appear to Ik,- 
 ospecUly atfcHed by "Zoo" conditions. 
 Ihe ( apr.mulgi.h.c. as well as the Strigi- 
 fornies for .-xaniple. are liable to accpiire 
 choroidal diseases. 
 
 16«] 
 
 nh.Ie e.xam.n.ng a number of common 
 Screech Owls, the writer found one individual, 
 about five years old and three years in captiv- 
 ity, that showed the followi- g conditions: 
 J^eft eye; usual Owl fundu,; well marked 
 disseminated choroiditis, affecting the nasal 
 aspect of the background more than the tem- 
 pora . The choroidal vessels show through a 
 number of atrophic areas. Usual pigment 
 spots smaller than normal. almo.st punctate. 
 Right fundus: the general appearance on this 
 side is of a striped gray, very much like the 
 warp and woof of some fabrics, or like the begin- 
 ning choroidal atrophy of myopia. In other 
 respects the right fundus resembles the left 
 
 Mr. Head informs me that in examining 
 with the mirror a Bluebird (Sialia sialis) in 
 captivity seven years, the vitreous humour 
 was found to be quite dull and foggy and the 
 fundus showed spots of an orange-r^d color. 
 This was very likely a diseased condition, as 
 ttie other eye had a cataract in it. 
 
 The writer has examined with the ophthal- 
 moscope the eyes of a number of Turkey 
 \ ultures (CaM«r/.. aura), practically domestic 
 animals in many American towns, and found 
 few of them healthy. In one case the bird 
 had cataract in each eye. In another there 
 was beginning central opacification of the 
 lens in the left eye; the same condition more 
 advanced in the right. A third had no len- 
 ticular changes, but owing to a suspicion that 
 he fundus findings might not be those of a 
 healthy individual the findings were not in- 
 cluded in the list described in Chapter IX. 
 Ihe following are the notes of this examina- 
 tion: Left fundus; general coloration steel 
 
EFFECTS OF DOMESTICATION ON THE FUNDUS OCULI 
 
 gray. Resembles the Bald Eagle. Pecten 
 large and apparently reaches posterior part of 
 lens. Optic nerve entrance entirely obscured 
 and ojjtie nerve fibres are persistent at teni- 
 porid margin of the disc. Uetinal reflexes 
 very distinct. At the upper and temporal 
 edge of the disc the white border of papilla 
 shows quite distinctly. Pecten very black 
 and in no part translucent; lies in well defined 
 coil-like folds. No definite visual areas can 
 be dilfcrentiated from the general fundus. 
 Fundus 'granular' in places. The refrac- 
 tion slightly hyperopic. 
 
 Beginning with his experience as a student 
 in the Thierartzneischule of the University of 
 Berlin in 18S8, the writer has examined the 
 eyes of many barnyard fowls, to find in them a 
 great variation in the fundu.s appearances even 
 of the same species. The following few de- 
 scriptions from notebooks will suffice to illus- 
 trate this point: 
 
 Bantam cock {Callus domesticus). Fun- 
 dus examination; direct, with electric ophthal- 
 moscope. Both backgrounds the same. The 
 whole eyeground is of a uniform 'pepper and 
 salt' and granular variety — the 'pepper' 
 predominating. The macular region shows 
 quite plainly, the fovea being represented by a 
 single star-like deposit which looks exactly 
 like (and may be) a crystal of cholesterin. 
 The disc is a long oval, almost but not en- 
 tirely covered by the pecten at each side but 
 
 (S3 
 
 quite clear at either end. The pecten changes 
 size and position under the examination but 
 not so (luickly as in the Crow, for cx.-.mple. 
 
 Large and mature 'spc-ckled hen," with a 
 light, brick-rcd iris. Kept in laboratorv of 
 St. Luke's IIosi)ital as a source of pure aVian 
 blood. The observations on the bantam 
 rooster just detailed almost entirely coincide 
 with the findings in this bird, except that no 
 single stellate formation in the macular region 
 was noticed. Skiascopy and pupil reflexes 
 alnjost the same. There was no noticeable 
 astigmatism developed in either. 
 
 A great variety of fundal pictures — nor- 
 mal and abnormal — are presented by our 
 Domestic Pigeons. The following are notes 
 on the fundi of the Homing or Homer Pigeon: 
 The background is readily seen in all these 
 domestic Pigeons. It bears a close resem- 
 blance to that of the common Hen, except 
 that the macular region is better defined in 
 the Pigeon. The sprinkling of fine, dark- 
 brown pigment over a reddish background, 
 interrupted here and there with colored points, 
 generally yellowish and glittering, giving 
 the whole a uniform appearance like fine 
 'mixed tweed" cloth seen from a distance of 
 a few feet, is very characteristic of this class 
 of fundi. The pecten is relatively small, 
 clubbed, spiral, black-brown and prevents 
 one from seeing more than a third of the 
 ovate disc. 
 
 m 
 
 
CiLVPTER IX 
 
 That one .n;.y properly answer many questions 
 wivolv,..! in the anatomy and physiolo^'v of the 
 ■rnporlani organs and tissues that constitute 
 111.- eyegroumi in Vertebrates it is neeessarv to 
 .•onsider not only the ophthalmoseopie. l.ut'lhe 
 maeroseopie and, in some instances, the nr 
 croscop.e findings. Although none of tliese 
 methods of research has as yet been .arried out 
 with any approaeli to completeness vet the 1ns- 
 tology of the retina and other visual'organs has 
 l.ccn satisfactorily studied in .Man. and a few 
 otiicr species of Vertehratse. by Cajal. Greeff 
 and others. Little attention has, however 
 been pai.l to the other two forms of investiga- 
 tion, that IS to avian ophthalmoscopvorto what 
 may ..e termed avian ophthalmamacroscopy. 
 
 OpJithalmoscopy is, in effect, a demonstra- 
 tion of the actual (comparative) size and -da- 
 tive position of the principal parts - nerves, 
 bloodvessels, [oil droplet (.')] dots, organs of 
 special sense-as well as the actual coloration 
 of the fun.lus oculi of the living Bird. Macro- 
 -scopy. on the other hand, reveals some .letaiis 
 of the Bird s eyeground not apparent or onlv 
 famtly apparent to tl. „ .ophthalmoscope. For 
 sample, the extent and other exact relations 
 of some of the areas of acute vision, as well 
 as definite, literal views of the pecten, are 
 better determined by naked-eye examinations 
 of prepared specimens than by viewing them 
 tlirough the pupil of animate species • To 
 
 an7t'i.i!;."\""'- '"'r-"" ""^ '"'"'"^ '" ""^ black 
 and «l„tc. ,lraw,ng,s (to indicate the maorosoopical 
 
 erely the ar.,.,f.s device to depict the'concavity ol 
 he evehall, elevafon of parts, etc.. and have no.Kng 
 to do with the fundal dot, and other coloration so w"ll 
 shown in the colored plates. 
 
 [64) 
 
 his may be added, ns elsewhere pointcl out. 
 that in certain instances the fine anntomv an.l 
 exact relation . of certain organs an.l tissues of 
 the background of the Bird's eye can b,- <leter- 
 m.„e,i only by a microscopical examination of 
 stained and injected sections of the parts 
 
 The following siK-cies (healthy adults) have 
 been examined either with the ophthal- 
 moscope „r by insfK-ction of prepared eve- 
 '•■'lls. or by both methods. I„ a number. 
 al>.., the eyes have been .sectioned and ex- 
 amined microscopically. These findings have 
 been mostly pictured in the text or by ap- 
 pended colored plates, and will now be 
 described. 
 
 A. RATITAE 
 
 Stnithioniformes 
 Nii-an or Northern Ostrich. Slruthio 
 
 view). The black and white drawing of this 
 fundus show.s a large, regularly oval papilla 
 spr.nkle<l with pigmented dots and circled by 
 a well-defined border. 
 
 The foreshortene.1 view of the -.ectcn gives 
 one the impression of an octopus-like figure 
 .vmg upon and almost covering the surface of 
 the optic disc, which is plainly visible beneath 
 and sprinkled with pigment dots. There are 
 readily counted twenty-four pectinate con- 
 volutions (12 double folds) that meet abo-, - 
 and are joined to an irregularly ovoid bodv - 
 -he crest or free margin of the marsupiun, - 
 
 tZTS\Z " '"'' "^ purse-string action. 
 The folds of the pecten are extremely thin and 
 en irely unlike the great majoritv of the con- 
 volutions in carinatc birds. 
 
 K^at. 
 
THE FIXDIS APPEAHAXf'ES IN VAHIOlS 
 
 OHDEHS OF BIRDS 65 
 
 n wl 
 
 m 
 
 F'K- in. Rufous Tinamou (Rhyncotus n<fe<<cem) x 10. 
 Macroscopic Appearances of the Fundus Oculi in the Preserved Eyes of Bird.. 
 
 iftii: : 
 
66 
 
 THE FUNDUS OTUIJ OF BIRDS 
 
 A loiiR, uniform band „f two .lark lines 
 .•n.l.winK a I.h.m.I.t wliii,. I,.„„) runs almost 
 horizontally across the fuiuhis above the 
 optic disc. About the middle point of the 
 l>an.l (above the disc and towards tlie nasal 
 asiKvt of the fundus) is a round ilepression 
 (O. l>lack in the center and surrounded by two 
 indistinct, pigmented semicircles, made' by a 
 wi.leninR of the parallel lines that enclose the 
 fundal band. 
 
 The extended major axis of the optic 
 entrance oval describes an anj-le of almost 
 45° with the inferior border of the retinal 
 band. 
 
 This angle the writer has called the ivfula- 
 papillary angle, from infula, a band, and pa- 
 pilla, the optic disc. 
 
 I'late I, page 121, gives a verj- good 
 Idea of the ophthalmoscopic apjK-aranees in 
 this .species. It represents tlie eyeground as 
 ■seen in specimens examined l)y Head in the 
 r.ardeus of the Hritish Zoological Society and 
 l)y the writer in a young male adult living in 
 the open and un.ler ideal conditions on the 
 Cawston Ostrich Farm near San Diego, Cali- 
 fornia. 
 
 The general color of the eyeground is dull 
 red, varied by a uniform sprinkling of lighter 
 red, round dots and gray granules. The 
 lower half of the fundus appears somewhat 
 grayer in tone than the upper sectors. This 
 appearance is probably due to the numerous 
 opaque nerve-fibres that extend from all 
 sides of the papilla as a center across the fun- 
 dus to the periphery of the ocular background. 
 The red coloration of the fundus is seen to be 
 more intense towards the upper half of the 
 eyeground. The optic nerve-entrance is very 
 broad, oval in shape, and its contour resembles 
 that of Rhea and the Tinamous. The mar- 
 gins of the nerve-head are very white and it 
 is possible with the mirror to 'see all around 
 the pecten. The centre of the disc, including 
 the parts near the root of the jiecten is 
 .slipplea with minute, brown pigment dots, 
 like black pepper grains. 
 
 The pecten projK-r rises from the nervehead 
 much like the same organ in the Tinamou 
 and presents, ophthalmoscopically, the ap- 
 pearance of a number of dull, dark, sepia- 
 
 brown tubercles. It does not project far 
 forwar.1 into the vitreous cavity, while its 
 outlines and contour may be <listinguishe.l 
 both above and below the disc. The jwctin- 
 ate niargins are formed of round or ovoid pro- 
 je.-tions. These nodular masses also app<Nir 
 to constitute the body of the pecten. 
 
 Tlie macula is situated about as it is in 
 Rliea; it is not very striking in appearance, 
 and takes the form of a creseenlic arrange- 
 ment of minute, gray dots. It is seen towards 
 the nasal side of the di.sc near its upix>r end, 
 and is not surrounded by the closed reflex- 
 ring noticed in so many avian fundi. 
 
 Rheifonnes 
 American OsTnicii. Rhea americana. 
 J-or an exact reproduction in color of the 
 ocular background of this bird see Plate II 
 page HI. which shows the left eye; erect 
 image. 
 
 The coloration of the fundus as a whole is 
 buff, merging into dull red at the periphery 
 It is stippled all over with minute dots of 
 a lighter tint, and much resembles the fun- 
 dus appearances of the Tinamou shown in 
 Plate V. 
 
 The optic disc appears to be a broad oval, 
 made up of white and coarse nerve bundles 
 that exhibit a faintly defined, fringe-like mar- 
 gin all around its periphery. Radiating for a 
 distance of about two disc-breadths across 
 the fundus are a few. dull-gray, opaque nerve 
 tibres that finally disappear into the back- 
 ground. 
 
 The macvla is situated slightly above and 
 to the nasal side of the optic papilla. It is 
 somewhat grayer than the surrounding eye- 
 ground; above, towards the outer side and 
 below the fovea, are a few pale, bright-green 
 reflex lines. 
 
 The pectm is a massive organ with saw-like 
 margins, the serrations being of a lighter 
 brown than the central body. The lower 
 part of the pecten is somewhat club-shaped, 
 and comes well forward toward the posterior 
 capsule of the lens. Between the projecUng 
 teeth of the pectinate serrations may be seen 
 a slight stippling of pigment-like black pepper 
 grains. 
 
 t:i 
 
THE FUNDUS APPEAUANCES IN VARIOUS ORDERS OF BIRDS 
 
 Casuariiformes 
 
 Wkmtkhmav Tahsowauy. Casuariiin 
 
 o<-eipU(ili.i. Tlu- colored drawiiiK shown on 
 Plate III, pii^je IW, is iritcniled to reproduce 
 nil ophtiialnioscopic view of the right eye by 
 the erect image. Two hirds (four eyes) 
 furnished almost identical pictures. 
 
 The fawn-colored njegrimnd is covered with 
 a minute, silver-gray .stipple, in the form of 
 fine, short lines with their long n.xes running 
 in u vertical direction. As these dotted lines 
 a|)i)roach the macular region they become 
 more and more ((jnvergent until they form a 
 l)rilliant cluster at the fovea. There is no 
 visible line of demarcation or retlex ring 
 separating this area from the general fundus 
 iirea. There are no visible choroidal blood 
 vessels or opacpie nerve fibres. 
 
 The opiic disc is long and boat-shaped, 
 with a reddish, apparently concave centre. 
 It is uniformly sprinkled with darker red 
 tlots, which, as they approach the margin 
 of the papilla, are more clo.sely packed, and 
 give the apijcarance of a shadow cast all 
 about the inner edge of the disc. The 
 margins of the nerve-head are distinctly 
 white, but they have not the "fibrous" 
 appearance seen in most avian backgrounds. 
 The chocolate-brown peden, much broader 
 at its base than at the apex, resembles a 
 corkscrew, its lateral elevation being not 
 unlike a cockscomb, with its six serrations 
 rounded off at the apex. Two central .serra- 
 tions come well forward towards the lens. 
 
 Apterygifonnes 
 Mantell Apteryx. Apteryx manlelli. 
 In July, 1914, the writer examined a Mantell 
 Apteryx in the London Zoo. The animal 
 was 12 years old and probably had monocu- 
 lar vision. The keeper said that (in daytime 
 especially) the bird had poor eyesight for 
 both distance and near. The bird's re- 
 fraction was by skiascopy myopic (about 
 1.50 D.) in either eye. The fundus appear- 
 ances arc exactly as Head has depicted 
 them in his drawing (Plate IV). In this 
 fundus picture the macular region is plainly 
 visible; and the pccten comes well forward and 
 is also easily seen. The ocular I k-ground is 
 
 67 
 
 uniformly orange-red, somewhat mollled with 
 brown. The brilliant, white, round disc is sur- 
 rounded by short, opaque nerve-fibre layers, 
 not entirely covered by the fenestrated base 
 of the long, large and conical peclni, whose 
 pointed end reaches almost I o the lens. There 
 are no signs of choroidal bloodvessels. 
 
 Tinamiformes 
 RiiFoi-.s TiNAMotJ. Rliijnrotii.i rufincenn. 
 (Figs. 117 and 78). A macroscopic picture 
 of the hack-ground shows a slight and rather 
 uniform pigmentation, darker towards the 
 jH'riphery. 
 
 The long, narrow comb-like pevlen some- 
 what resembles w hen seen from before back- 
 wards, a small crayfish. It is made up of 
 from 48 to .50 convolutions, the dorsal crest 
 forming an irregular triaigle with a short 
 .spine projecting from its inferior end. 
 
 The macula is plainly marked above and 
 on the nasal .side of the pecteii, about half a 
 disc-length from the anterior terminal of the 
 papilla. 
 
 AIautineta Tinamou. Calodroma clcgans. 
 A picture of the left ocular fundus (by the 
 erect method) is furnished by Plata \ . 
 page 125. This taxonomically interesting 
 spi'eies presents a background whose colora- 
 tion is, in the main, a deep gray, the lower 
 half merging into dull orange. The whole 
 of the fundi is covered by a collection of 
 tiny dots packed closely together. In the 
 upper half of the field they are white, but 
 from the region of the disc and downwards 
 they become a dull orange color. Crossing 
 the fundus and running vertically on either 
 side of the papilla are several orange-red 
 choroidal capillaries. 
 
 The macula appears as a dull-gray area, 
 with a brilliant white central spot surr^ unded 
 by a small, pale-green, streaked, reflex ring. 
 It is plainly visible on the nasal side of the 
 pecten. The optic nerve entrance is oval 
 in shajM; and exceptionally broad. 
 
 The mass of the pecten almost completely 
 covers the optic papilla, which is quite white 
 and looks like a mass of coarse opaque 
 nerve fibres. Ihe optic margins are bor- 
 dered with gray pigment, from which spring 
 
 in' 
 
 fi f! 
 i 
 
 m 
 
68 
 
 :' f.-w short ..,mf,u,. norve fibres. Tl..- wrtrn 
 " '•''."<-»l'"'- t'r..un. ami i„ ,„|,li,i„„ ,„ ;„ 
 "'"«iv,. apiH^aran.,- is niu.h shorter than 
 M..- Hamo orKa,, i„ n,„st of the birds oxaniin.-.l. 
 All imrts a,„l all .l.-tails of this ,H-clon can bo 
 vio«... w.th the mirror without the least 
 ..Iheulty It .s easy to see that it is fringed 
 •'II around wth pointed tabs, that the central 
 I>->r .on or r.dRo i,. serrated and that it ron.e. 
 «■.■ 1 orwar.1 towards the I. n.s. In exan.in- 
 
 l'rm,«h he unddated pupil the jn-cten seems 
 
 I" hi! the pupillarj- area so that most of 
 
 he fundus ,s obscured an.l shows through 
 
 .e fnuRe about the papilla a. a light shines 
 
 through a grating. 
 
 THE FUNDIS OTILI OF DIHDs 
 
 CARIXATAE 
 
 Gallifonnes 
 Yarkell ClKA«.sow. (rax yUo.m. The 
 fundus app<.„r„„ces of this bir.l are depicted 
 "; J late \I. page U5, and are the result 
 "f an exammation of four eyes in two speci- 
 "K-ns. The four backgrounds were foun.l 
 to be identical in all resp<-cts. 
 
 Thv cyeyround is a dull, l.-aden grav 
 covered w,th tiny, white dots. There ar'e 
 no visible choroidal vessels. 
 
 The papilla appears as a long oval, whose 
 central zone is dull-orange mingled with 
 ■"■"ute, dark-brown dots. It also presents 
 a marginal fringe of while. A few opaque 
 nerve fibres exlen.i on either si.le of the 
 disc across the fcndus, but for a short dis- 
 tance only. 
 
 The peckn, of spiral form, is colored dark 
 chocolate-brown I, seems to taper quite 
 decidedly where it joins the disc, and looks 
 like the roots of a tree at its distal end, 
 where the rootlets bury theniselve. n the 
 disc. Just above the disc, some little dis- 
 tance to the nasal side of the pt>cten is •, 
 round, gray, softly outline.l area near whi.i, 
 IS seen a well-marked reflex of a pale blue- 
 green tone. 
 
 Hate VII, page 127 depicts an ophthalmo- 
 scopic view of this species. 
 
 The ,-y,ground is .lull, slaty gray, under- 
 iM.ig numlHTs of fine, light-gray dots. These 
 •lots are uniformly scattere.l over the fundus 
 x<cpt towards the uH.,al side. Her,-, on a 
 level with the sup..rior en.l of the optic 
 "cr/e and ,n the Vlirection of the macular 
 area, hey are brilliant white, are clo.sely 
 packe.1 together and arc devoid of a reflex- 
 ring. "* 
 
 Kxtending from either si.le of the optic 
 'l"<c an.l running at right angles to that 
 organ are a few. rather fine, semitranslu- 
 cent nerve fibn-s, which are lost towards 
 tne jXTiphery. 
 
 The opiir dhc, whose upper en.l is shnpe.l 
 I'ke the sharp bow of a boat, app«.ars to be 
 compose.1 .,f a mass of brilliant, white, .,p„nue 
 nerve fibres. ' 
 
 The Kr/.«, of the usual chocolate brown 
 color, IS massive and .s.,niewhat club-shaped 
 It extends well forward towards the lens 
 an.l tapers rapidly as it approaches the 
 superior end of the nerve. 
 
 C.UFOH.MA Valley Qvail. LophoH„x 
 cahforn.eu, valhcola. (Figs. 110 and 79.) An 
 cxam.nati.,,, ..f this background with the 
 nakcl eye discl..ses no vell-defincd macular 
 n-gion, at l.-iust not in this .specimen; it may 
 .e that in better preserved material a shallow 
 fovea can be isolate.l. The pccten presents 
 nterop.,stenorly an elongatul, acuminate 
 hgure with 30 convolutions, or 15 folds 
 regularly .lisposcd on either .si.le .,f „ straight' 
 '"ear. m-Hlian .rest, that runs the whole' 
 length of the .,D,K-r aspect of the free bonier 
 Hie conv.ilu' o.is are separate.l at severed 
 points, especially near the mi.ldle, so that 
 glimpses of the .lotted, whitish opIir ml nr 
 iH'iieath may be seen. 
 
 HAnLEy,;i.N Qiail. Coturnix hislrio. 
 Ihe remarkable fun.lus of this bird, view , 
 with the .,phthnlm.,sc..pt>, is portrav.-d as 
 •ate \ HI, page 127, of this monogn.r.h. 
 The picture is the result .,f an examination 
 of several individuals, all exhibiting i.lentical 
 eyegrounds. 
 
 The general color nj the ocular background 
 's light gray .prinkl.-d with minute granules 
 which give, it the appearance of a rough 
 surface. This granular surface appears 
 
THE FlNDrs API'EAHAXCES I.\ VAHIOl'S ORDERS OF BIRDS 
 
 (i» 
 
 ■11'' 
 
 Fig. 119. British Wood Pigeon {Columba palumbua) xlO. 
 Macroscopic Appearances of the Fundus Oculi in the Preserved Eyes of Birds. 
 
70 
 
 whi... or Ii,I.| ,^„y ^.,,.„ ,|i„,,|v i||u„,i„„,...| 
 u; n..l..c.,...| ,i,,., of th.. ..ph,h..l„.o- 
 
 "•'"pic mirror. 
 TIm- ,,;,//,. „,„,.;,,,„/ i,.,.^ , 
 
 "''"'•. «l...rt. ,.o„rs... .,,„„,,„. ,i,,„.^ „^ 
 : ;r '^ ''""^""1. l-inK lo„K ,uu| narrow. 
 
 l'r..j.T ,„«. .s..rr„t,..l jaws „f ,l,e Swor.l Ki,h 
 
 tliiii, opaciiic iicrvf fihr,.,. 
 TIk. /„.,./,.„ is li«hl..r l.rown in .-olor than 
 
 «'ll' tl... pap.lla. On ..illK-r .si.l,. of il an- « 
 <•«■ nnnnl,. .lol.s of l.rown piK„u.„|. Tlu- 
 
 ".«.t...l, ...Iky n.ass which, however, ox- 
 
 "" •: «'■" f""*-^-' """ 11..' vitreous cavity 
 to the |,oster.or surface of the hw.s. \o 
 'l.'lHul,. ,„a,.uh,r region was .liscovere.l in the 
 various s|)eeiMieiis examined. 
 
 THE FUNDUS OCULI OF DIHDS 
 
 Columbiformes 
 
 \Vo.n,;a Wcncia Dovk. locosarcin 
 
 ^''•..'".(h,-s.ll8an.l81;n.acroseo,.ic views.) 
 
 lhcrel,„a,„,he,.yesof,he„Me.s,..cime„ 
 
 .-..ne.. showed an unusually smooth 
 
 /ri'e loiiK, narrow j>eHen resemlWe.s the 
 
 into";; , *'" 'ir' ''*«^""' "•"' p-i-t« 
 
 to h,. vitreous hke a house-he«ti„K ra.lia- 
 
 t-r v.th ahout 19 coils, forming S8 (or 
 
 ...;n-) convolutions in all. The rid,.o-like 
 
 rest conceals the up.H-r mid.lle line of the 
 
 ;■':;;""'■ ■"-'* -l"^-''. in its tum. cntirdv 
 
 'l.>cures a v.ew of ,he oplie entrance. Th'e 
 
 lower free horder "f the niarsupium appears 
 
 us a hroad parallelogram covered with ,r 
 
 "'-"t ,'ra,ns conlra.sting sharply with the 
 
 -.perior ..nd. whi,.h comes gradually to a 
 
 rounded point. .» i" « 
 
 ^^Jliere is no nrU-defi^ed macular or Joreal 
 
 As shown in I'lufe IX, page 129, the 
 "cular background of thi.s .secies pr^ln 
 when exannned by the ophthalnmsc";^ 'a 
 " f° .'; gray tint. White dots, lighting up 
 Hie fundus, are scattered over the entire fold 
 A few choroidal capillaries are to be seen 
 
 Iho op^,cd^»c forms « |„„„ „v„|; it „,,. 
 
 l-ars as, f,t wen- compos..] Ufa collection 
 "'wh.lehl.r..s. and the.. s...m bunched to- 
 
 P-.t.n. Op»,,ne nerve (ibn-s radiate from 
 
 crcumfereme of the p,.pilh, while s^-v- 
 
 •ral „ran«...r..d (choroidal) ve.ss..|s. inter- 
 
 J-rse,! with pigment dots, run o„ either si.le 
 
 The prr/.« „p,H.ars as an exceptiom.llv 
 
 "'K. corrugated, dark-br.mn ma.ss. .S..„ 
 
 through the mirror from above it has the 
 
 a|.|K-aran«. of a piece of tarred ro,H.. 
 
 ^hv macular area is scrn to the inner 
 
 nd_ The .sheen of the pale-grcvn reflex 
 
 hat plays about it when illuminated In- the 
 
 hght of the ophth«lmosco,H. loots' like 
 
 ^Icred .si k. The fovea ha.s the apix-aranc e 
 
 froM tT'/"^'" fl"«'. -""-thing like that 
 
 ^o..»'>""-eye lantern sc^nclcse at hand. 
 Only one macula can be s»-en 
 
 bRrm,, Wooo PioEoN. Volumba palum- 
 
 The /^r "V"'' '"=""—»»- views.) 
 riie i„c^,ro«„J of thi, .peeies shows a, 
 elongated, pointed, ovoid pecten, made up of 
 l„r. I '^*""« P''™'i«n.'' (about at in numb<.r) 
 bod .l",,"^'''" nPf-r margin. The main 
 tjodj of the pecten is not conci-aled. as it 
 
 above which has an abrupt flattened app..„r- 
 2-^ Wow. an acute sloping teriniLai':;. 
 
 A faint and doubljul foreal dcpresHm is 
 
 ^.dt of the di.sc m some specimens examined 
 but this area does not show plainly in the 
 individual here pictured. 
 
 The ophthalmoscopic appearances in this 
 si>ec.es are depicted in Plate X. page W9. 
 The general tint of the ocular back- 
 ground, as «.en by the erect image, is p„|e 
 ■slate-gray The eyeground is co ' ed T 
 very small, dull-white dots .so that the whole 
 fundus presents a lighter shade of gray 
 than It otherwise would. On the low/r 
 half and each side of the optic disc art' 
 .seen several orange colored choroidal bloo<l- 
 vcssels. which become more numerous as one 
 approaches the periphery. Extending 7i 
 
THE FUNDUS APPKAHANCKS IN VAHIOIS ORDERS OF BIRDS 
 
 f:. 
 
 riRht anj{li\s to the (tiipilliiry iimrKin im- a 
 fi'w o|m<|uc tH-rv*' HI>rt"H. 
 
 A little above the su|«Tior eii.i ,.f the 
 optic iierve-hend ami towanU tin- iiiisul 
 side, is a small, rouml, apparently somewliitt 
 ciepr..s.He(J maeular area of a cliill-Kniy lone. 
 From its margins runs a doiiliK row of tine, 
 l.lue-Kreen, translucent lines wliieh form 
 alioiit it a broken or irre^ilur rellex rinK. 
 The bird iK-comes unnxiially reslle>i when 
 the iij{ht from the oplithalinoH<<,pic mirror 
 is fmused on this part of the fundus. 
 
 (ilimpses of portions of ih,. „ptic dhc 
 nhow it to Im- dead whit.-, and it seems to 
 have a fringe of short 6bns of the same color 
 all about its edges. At the junction of 
 the pecten with the nervo-hcad, i.e.. along 
 the central area of the lat» r, one sees numer- 
 ous brown pigment dots thai ap|)ear like 
 small rootlets or capillaries and give a reticu- 
 late appearance to the papilla. 
 
 The pecteii itself has a dark chocolute- 
 brown color and a corkscrew contour; it is 
 unusually long and narrow, and its lower 
 segment app<'ars to conic well forward 
 towards the lens. 
 
 ViCToHiA CuowsKD Pir;Kov. Goura 
 victoria. The fundus oculi of this sfKH-ies, 
 depicted as Plate XI, page 131, right eye, 
 erect image, is of the usual gray color seen in 
 Pigeons and Doves. The eyeground gen- 
 « rally is covered with minute white dots. 
 On the upper and nasal .side of the fundus 
 i.s the macula, a small dull-gray area sur- 
 rounded by a gray and green reflex of small 
 lines. 
 
 The optic disc is long, narrow, boat-shaped 
 and a little rounded at the upper end. It 
 looks ;i it were rather hollow and gray in 
 the centre, with a white rim all around. 
 A network of small, brown, pigment dots 
 is disposed along the centre on either side 
 of the pecten; and some opaque nerve fibres 
 extend across the fundus on all sides of 
 the nerve. 
 
 The pecten is of the usual dark, chocolate 
 tint. It is corkscrew-like in appearance, 
 but one end is rather club-shaped and looks 
 as if it were covered with small brown nodules. 
 This segment comes well forward towards 
 
 71 
 
 the leu-, but not so much as in the Woo<I 
 PiKcon; olherwisc the fundus closely re- 
 sembles the eyeground of thai bird. 
 
 RalUformei 
 
 Amkiii(»\ f(K>T. Fidica amerirana. 
 (Figs. UO and84.J The backgnmnd of this 
 s|K'cies, m.u roscopicall\ considered, shows. 
 obliciuely acp s the fundus but not reaching 
 the jMriphery at either end, a "split stick" 
 figurt'-a narrow band of iinpigmtnted ntina 
 depicted by two doited lines of pignu-nt, 
 the line towards the optic disc containing 
 more granules than the other. Midway 
 between thi> tw,- ends of this figure is a 
 circle of |)igment. twice the width of the band 
 itself, made by an extension of the pigmented 
 borders that form the boundaries of the 
 l>and. In the exact center of the circle is a 
 plainly marked pigment dot. 
 
 The large, thick pcrttu is wider at its middle 
 than at either end. It has about iH clearly 
 defined convolutions, or 10 double folds. 
 Uhi'n seen from above one may perceive 
 between the.se plications not only the bla<k 
 c« iilral body of the pecten but the papillary 
 edges. The free border of the pecten has ii".. 
 definit.- k.-.l but the upper margins of the 
 convolutions join to form a serrated wavy 
 line reaching from one terminal to the 
 other. This practically naked, saw-like 
 crest is unusual in the pcctens the writer 
 has •xamined. 
 
 The long axis of the papilla prolonged 
 to nuvl the n-linal band iiiakes with it an 
 angle of about TO', the inju ' tpapillary angle. 
 Chfstei) Coot. Fulica cri.ilatu In the 
 several s] .ens examined ophthalnio- 
 .scopically. Uie fundus ap{)earanccs of this 
 Australian bird (see Plate XII, paj.'e 131) 
 were practically itientical. The colored re- 
 protluctioii presents the left background by 
 the usual direct i lethod. 
 
 The predominant color of the eyeground 
 is dull gray, everywhere sprinkled with mi- 
 nute, white dots that are more clearly seen 
 above the su{)erior termination of the optic 
 nerve and to the nasal side of the pecten. 
 Although this area is (judging from the 
 effect of the light thrown upon various 
 
 m-f!kv 
 
w 
 
 TUF FINDIS (KCLI OF BIRDS 
 
 Fi(?. lil. (iriat Oestetl (irelw (,Pudicipea crintataa) XU. 
 Macroscopic Appearances of the Funda, Oculi in the Preserved Eyes of Birds. 
 
THE FINDIS AITE.VK.\N< KS r\ V.VKKH s OKt^KHS OF HIHI)S 73 
 
 quattrantst of Ihc fumlui l>y tin- imrrori vrr> 
 iirniiitivr lo Mght Iht-r*' \* no ollur ophilmi- 
 IlKMM'opic iiKlii'iition of a iiia<-iiltir rrj^imi. 
 
 Tho loiix <)i>t,r (/(.«.■ ii while, willi ii ft w 
 liny |>i|{ni<'Mt lUiit nlioiil its nniririn-- Tin' 
 IMilfu in li((htrr lirowii Ihun in tin- majority 
 of liirtl^; it it v«t>' larnc uUtm-l liiilin); 
 Ihf ilisc from view Many o|mc|U)- ni-rvt- 
 fil)r«'»i rmlialf from the |>a|)illary <ir«iim- 
 frrftiM' anil rxli-nil M-viTal I'i i- lir<-ailtlis 
 ac-roN.^ the fumliis. Owin^ tn !,,■• Iur(,'i' .>«izr 
 of fhf iMH'ten ami tin- Nniall iiii|iil il i>i im- 
 pos.sihli' lo ol)lain a HatiKfactoi-y lateral view 
 of till' iH-elen. wliieh nlniosi covers Iht- pupil- 
 lary area with its nms-.l\.- eliil>-»lia|Mil etui. 
 
 Tin' .\nicri<'an roiii-. hit of t|ui lunl 
 Fiilini (/wrriVoMfi -lln^a finiiln Inu.^l nlfnti- 
 cal, uplithalmoM-opirall '.uilli tin- ^peeirt. 
 
 Ifkcaiia Hail. Aniinnln •'pici'hu 'li,c 
 ophthalmoHcopic picture of liii- (I'rd. rrp- 
 resetitinn Iht- riglit eye, it, se,n .i> I , i.- Xlll. 
 paK<> \^S. 
 
 The eyrgTonnd is a ver\ pair iiiiifunii ;.'ray 
 stippled with .jarker ^ruy and vliite dol- 
 thus K'ving the whole field .1 trra'iul.ir ap- 
 pt-arancc. 
 
 The horizontally oval macular ana ion 
 the na.sal aspect near the up|H'r end of the 
 »lisf) assumes a pinkish lone. .M its center 
 is a small pit which, in the lif;ht of the mirror, 
 opiH-ars a.s dark gray with a brilliant, white 
 central clot. Arountl the macular ri-ffion is 
 a pale, hlue-ffray reflex, which lo.ses itself in 
 the general tone of the fundus liuf appears 
 quite sharp on the inner side of the oval 
 macular region. 
 
 The disc is a narrow, wJiite oval, whose 
 major axis measures about one-third the 
 height of the pecten. .V number of opa<|ue 
 nerve fibres run across the background at 
 right angles to the papilla and fade into the 
 general gray of the fundus. 
 
 The pecten arises from the upjH'r segment 
 of the disc, spreads out on it like the root of 
 a tree and gradually disap|>ears into the 
 papillary substance. From this root a long, 
 slender, spiral form projects into the vitreous. 
 It is brown in color, is of uniform width, 
 looks like a corkscrew and extends forwards 
 and outwards as far as the eye can see, 
 
 l<Niking il- if it were pri'ssed against the lower 
 part of the lehs. The anterior enil of the 
 I"'" tell i* i!iM ■h ilarker in (nlor than it» |)o«- 
 lerior hi. •• li is ijuile Hut. 
 
 The fl ,!•. iH'uli of the Weka Hails ^(}ry. 
 
 ilnimii Is '(iiite similar to the iHular ba, k- 
 grouuit of this s|i>-<'imen. 
 
 Podicipediformet 
 
 (JllKAT <'ltt;sT>:0 (illFUK Pixiiripcii 
 
 <ri.ilalii.i. (Figs. W| and H3.) \ nnuro- 
 seopie examination of the fundim oculi in 
 this s|M'eies reveals a broad retinal Itand, uni- 
 form III width, that extends from the nasal 
 [MTiphery aenn. the fundus and is lost in the 
 pigment of the opposite side. It is half as 
 will.' :is the minor axis of the oval dis*- and, 
 ii'niig its whole length, is depicted by two 
 paiallil lines of pigment dots— the inferior 
 bonier containing the more minierous grains. 
 The nasal half of the wide band is bisected 
 l)y M narrower, almost linear, ribbon coni- 
 poseil of minute black dots that are most 
 imnierous at the- |)eriphc"> of the field, 
 becoming fainter and fa >o> ii-iSil jut 
 before the iiiaeula is re.u ii I when they 
 clisap|H-ar altogethei' 
 
 \\ about a Ion;; , I I'. .Ik I;.'. i- fro!n 
 the superior end ■•• ihf •.■■■.i- >.;•. 'ii its 
 nasal side-, is a I .,. .'rc':. ' nti'i' pig- 
 nienled. disc-like ■: ■ r ».,.,»» ..<?ed 
 
 within and some, In - ^ .! ■. ;•. ,tiits 
 of the retinal bauii. •. i . „ ■ i •■ 
 
 central, depressi-d lighli/ " i. ., ' (ml',; 
 l>v a small ring of pigui m' 
 
 The pecten covers the cjplu i..iiance, and 
 has the steam radiator-like form of the 
 Wonga Dove. However, this sjH'cies ex- 
 hibits ii convolutions, the free border shows 
 three ch-finite elevations above and it has a 
 (lov\), opaciue keel to which all li double 
 folds are firmly united. 
 
 The angle made by projecting the major 
 axis of the oval optic papilla until it bisects 
 the lower border of the retinal band, the 
 infulapapillary angle, is, approximately, 70°. 
 
 In injected specimens of this species (as 
 well as occasionally in individuals not so 
 treated) the choroidal vessels show very 
 plainly. 
 
74 
 
 THE FUNDUS OCULI OF BIRDS 
 
 Fig. U3. Pigeon Guillemot {Cepphiu columba) X9. 
 Macroscopic Appearances oi the Fundus Oculi in the Preserved Eyes of Birds. 
 
 i< .?f^. Av^mnHTjiEBK^ffiBK^mfr ?«MMe»Bnv>ssenwsin« 
 
THE FUNDUS APPEARANCES IN VARIOUS ORDERS OF BIRDS 
 
 75 
 
 Colymbifonnes 
 
 Pacific liOox. Gavia pacifica. Tho 
 writer has never been able to examine more 
 than one individual of this sjiecii •^, or any 
 other Diver. He was obhged to use the 
 ophthalmoscope, with little protection from 
 the blazing sun of a Californian noon-day, 
 upon a recently dead bird. The examination 
 was necessarily incomplete. The fundus was 
 light gray, dotted over with dark pigment 
 granules; the pectcn was large and there 
 was a well-marked porus opticus. 
 
 Sphenisciformes 
 
 Black-footed (Cape) Penguin. Sphen- 
 i.icu.i demersus. The eyeground of this 
 species is depicted as Plate XIV, on page 133 
 of this monograph. 
 
 The dominant color of the fundus is bright 
 red shading to crimson. It is generally 
 stippled with minute, dark-red and orange 
 dots, much like grains of sand. About a 
 disc-length from the upper end of the optic 
 disc these dots become grayish-white; indeed, 
 the fundal coloration is distinctly gray 
 towards the upper half of the eyegi'ound. 
 In a region the same distance towards the 
 temporal aspect of the background may be 
 seen a clu.ster of pinpoint, brilliant, white 
 dots ill the macular area. Penguins use the 
 nictating membrane very frequently when 
 light is thrown on this part of the eyeground. 
 
 The optic disc exhibits enamel-white edges; 
 it is hollowed out in the centre, like a sewing- 
 niachine shuttle. Running across this con- 
 cavity and at right angles to the margin of the 
 di.sc one sees a large number of gray fibres. 
 
 The pecten lies along the centre of the 
 nerve, where it is orange-red in color and 
 mottled with minute, brown pigment dots. 
 The pecten has the usual dark chocolate- 
 brown shade. It is of spiral form, like a cork- 
 screw laid on its side. A few slender opaque 
 nerve fibres are visible on each side of and at 
 right angles to the disc. 
 
 Procellariifonnes 
 
 Dark-bodied Shearwateb. Puffinus 
 griseus. (Figs. 122 and 85.) The fundus of 
 this species, as seen by the naked eye, 
 
 exhibits a darkly outlined band, widest at 
 the nasal extremity and at its middle, with 
 irregularly pigmented borders and a lighter 
 center, runs across the field of view from 
 one periphery to the other. Its central 
 third is shown as uncolored except for a 
 line of pigment that divides it into two equal 
 strips — thus constituting a linear fovea, the 
 circlet seen in some other band-like areas 
 being absent. 
 
 There are 20 convolutions in the rather 
 short, thick pecten. These double coils are 
 so divided where they join the compara- 
 tively narrow sloping crest that glimpses 
 may be had of the nerve head below. The 
 keel covering the upper portion of free border 
 is prolonged into a blunt, rounded process, 
 partly formed by the larger and higher 
 posterior "teeth" or segments of the niar- 
 supiiim. 
 
 What has by the writer been termed the in- 
 fulapapillary angle is 5o^. This is made by 
 projecting the major axis of the papilla to meet 
 the lower margin of the transverse sensitive 
 area of acute vision. 
 
 Alciformes 
 
 Pigeon Guillemot. Cepphus columha. 
 (Figs. 23 and 82.) The background of this 
 species, when viewefl maeroscopically, re- 
 veals a narrow, uniform, pigmented retinal 
 band that stretches across the field of view 
 from one periphery to the other. At a point 
 where it approaches the superior end of the 
 papilla is placed a circular area (the fovea) 
 whose diameter is twice the width of the 
 band. 
 
 The pecten is remarkable in that it rarely 
 obscures a viev.- of th' margins of the long, 
 broad, ovoid, optic nerve-head, which has its 
 pointed extremity upwards. There are .SO 
 convolutions in the pjctii'.afe mass, and 
 occasional views can be had of the papilla 
 through clefts in it. The ridge-like, free 
 border of the pecten is linear for a third 
 of its length below but follows the undula- 
 tions of the convulutions beneath it until 
 it reaches its superior end. The double 
 folds in this organ are longest and most 
 voluminous at their middle, where the 
 
 BHi^'BmGBx^KnKJi;ifs«ii'?jMiiJWSK«MivrKEitimrTir«aiifirHiB^ 
 
 I lH'fluWi'flHK13»''1KWUV 
 
 r :■«.,»;;; M^iMJiiiiBifiv-ii;; 
 
76 
 
 THE FrXDlS (K'lL, ov BfKDS 
 
 Pi*-' H4. Ilerriiij; f;„|| (/„ 
 
 anis argentatim) X7..5. 
 
 FiK. l-i5. IIuds„„ia„ < „rlc» ,'.V«m„„»., /,,„!,,_ „,,^ 
 Macrosoopi,. A,.,>eara.,„. „f „,e Kundu. ...„,i i„ t,,.. ,W ., Kye, of 
 
 'Isonirus}. 
 
 Oirda. 
 
 ^^^^^PIM 
 
 Si 
 
 Si?SJ^^^;fRij;::>'|-:^'S;: 
 
THE FUNDUS APPEARAxVCES IN VARIOUS ORDERS OF BIRDS 77 
 
 crest or keel is elevated to n sharp point, 
 and towards which the olher folds are in- 
 clined. They gradually decrease in size 
 towards both the posterior free margin — 
 an unusual disposition — and to the anterior 
 or superior terminal of the optic entrance, 
 in accordance with the rule. 
 
 The longtT axis of the disc projected until 
 it meets the retinal hand makes with the 
 latter an infulnpapillary angle of about 05°. 
 
 I'lFKlN. Fratcreulu arrlica. The eye- 
 ground of this remarkable sjjecies is portrayed 
 as Plate XV, page 135. It represents the 
 left eye as seen by the direct ophthulnio- 
 .scopic metho<l. 
 
 The general color of the eyeground is red, 
 rather uniformly stippled with small, mixed, 
 light-red and dark-gray dots, .\bove the 
 upper end of the optic disc and towards the 
 temporal .side is a small, round, red area ."ur- 
 rounded by a pale, light-gray film, shot with 
 bright lines on the outer and inner margins — 
 doubtless the macular region with its central 
 fovea. Head noticed that not only this area 
 but most of the upper half of the fundus is 
 very sensitive to light. 
 
 The optir papilla, oblong, narrow and with 
 a rounde(i upper extremity, lies low down in 
 the ;yeground, while the |)ecten extends well 
 forward and behind the lower margin of the 
 pupil. .\ view of the nerve-head is much 
 obscured by the body of the massive pecten 
 which almost covers it when seen, as with the 
 mirror, from above downward. The small 
 segment visible with the ophthalmoscope 
 appears not brilliant white but rather a bluish- 
 white, the margins of the pecten being covered 
 with black pigment. 
 
 Extending at right angles to the disc on 
 both sides are a few very fine, gray opaque 
 nerve fibres, that finally disappear in the 
 fundal periphery. The pecten is of the usual 
 chocolate-I)rown color and comes well for- 
 ward towards the lens, especially in its infe- 
 rior aspect. 
 
 Larifonnes 
 
 HEnm.Nti (liLL. Larn.i argentalus. (Figs. 
 124 and 86; macroscopic view.) In this 
 species the upper and more pointed extremity 
 of the pecten points slightly to the temporal 
 
 side of a linear fnrea that is drawn as a rather 
 tiroad, short, retinal band that skirts the clear 
 area and stretches in a slightly obliiiue direc- 
 tion across about one-third of the central 
 field. The icneal slit (nearly as long as the 
 optic di.sc is wide) occupies a widened portion 
 of the band-like process and shows a line of 
 pigment dots along its upper margin. 
 
 The very broad, long pecten covers an 
 equally large papilla. It has 36 thin, leaf-like 
 convolutions which, in prepared .specimens, 
 do not obscure the margins of the nerve-head, 
 whose canoe-shaped outlines are everywhere 
 visible from above, except at the bow and 
 stern. The fre( irder, comparatively wid(>, 
 is deeply i)ignieii rd, does not reach the supe- 
 rior extremity of the pecten and has the 
 appearance of an car of maize. The medial 
 and posterior leaflets of the pecten are the 
 longest, only the anterior five becoming 
 smaller as they approach the upper extremity 
 of the papilla. 
 
 The infulapapillarj- angle measures about 60? 
 
 The ophthalmoxcopic appearances of the 
 background are the same in both the European 
 and New World species. A large number of 
 healthy individuals were examined both by 
 Mr. Head and the writer. 
 
 The ocular background of this bird is quite 
 similar to that of Larus marinus. The 
 prevailing color is dull brown, the upper half 
 being interspersed ivith masses of small gray 
 dots, that assume a pink hue downwards 
 from the upper end of the optic disc. One 
 notices in this region, also, many dull-red, 
 choroidal capillaries that run parallel to the 
 sides of the elongated nerve-head. 
 
 .\ little above the upper end of the papilla, 
 towards its inner or nasal side, is the fovea 
 ccntrali.i. a brownish red dot, in the centre of 
 a rather dull area. This macular region is 
 enclosed by two clear, bright green rings, or 
 rellex circles. 
 
 The optic r/i> (papilla) appears to be made 
 up of very short, brilliant white and rather 
 coarse opa<|ue nerve fibres. Extending fro.n 
 its margins are a few, dull-gray, opaciue nerve 
 fibres, thai radiate from the elongated papilla 
 but fade awny in the [MTiphery of the back- 
 ground. 
 
 
 .,'•-i■.>'.^7<■S•J*^:^.*^^:;l 
 
78 
 
 THE FUNDUS OCUU OF BIRDS 
 
 ^\^ l-^e. l(I,«.k-...lli«l Plover (S.natarola ...uatarola) XO. 
 
 Fi^. H7. Great l)„,tard {Oli, tarda) xSJi 
 
 .Macrosropi. ApfM-aranc^s of the Fundu., Oculi i 
 
 in the Preserved Eyes of Birds. 
 
 
 ■.'*'■ ■V'?-<i'' ■'■ V-V 
 
THE Fl XDl-S APPEARANTES IN VAHIOrs ORDERS OF BIROS 
 
 The prrlrn, of tl„. „sii,il rliwoli.tc-l.rown 
 rolor. IS .livi.le.l into (i,l)out) fo.irtron .on- 
 voliit.oMs. which .-.re inon- masMvc Im-Ionv. 
 They .•Mend well forward towards tho lens. 
 
 At Ih.- apparent junelion of th- jM-clen with 
 the optic nerve the disc is rather orance-red 
 in tone. 
 
 (;nF;AT HL.\(K-nA( KKD r.iLL. L(m,.i mari- 
 nii.-. Ph.le X\-f. pa«,- 13.5, depicts the fundus 
 a[.IK-arar>.es of th,- left eye in this species, 
 riie Kcncral coloration of the evcRround 
 vanes from a (hill ^ray to a (hill hrown ~ 
 mostly the latter — traversing which are 
 many rechhsh. choroidal bloodvessels niiininjj 
 iMore or less in a vertical direction. It is the 
 niiinl.er and visibility „f these .apillaries that 
 Uivc the n-d tone to an eyegroiind essentiallv 
 iir.xy. 
 
 The optic di.ir is a long, narrow oval, f|iii(e 
 white, with a <|uantity of fine ^ray lines radi- 
 ating; III all (hrections from the i),ipillary niar- 
 f-'iii. On tli<- inner asix-ct of the eve^round 
 tlie macula is s«-n. It is .situated ahout one 
 disc-lciiKth from the upper end of the pecten 
 and half a dise-leiiKth al)ove the end of the 
 same or>;aii on the inner side. 
 
 The iiiiiriila reseniMes a hlue-grwn flake of 
 irid<-seent glass. It is of oval shai)e with a 
 reddish-hrown center, which, however, is 
 unprovided with a reflex ring. 
 
 The prHrn apjuars to he in folds; the lower, 
 or l.roader, portion e.\teniis well forward' 
 lowarils the lens and turns towards the nasal 
 side of the l)ir(i's head. The inner (|uadrants 
 of the fundus are more easily seen with the 
 ophthalmoscope tlian the outer half but, so 
 far as the latter area is visil)le, there is no sign 
 of a second macula on the outer part of the 
 eyeground. 
 
 Charadriiformes 
 
 Hl.4( K-MKi.i.iKo Plover. SquaUtrola squa- 
 tarola. (Figs, hm an.l 89; maeroseopie 
 view.) Preserved eyes of this s|)ecies present 
 a moderately broad, grayish rilinal band, 
 whose borders, drawn as pigmented Ihrough- 
 oul. extend somewhat obliquely across the 
 fundus from one margin to the other. Near 
 the middh! point of (his n-tinal area is a cir- 
 eular, craleriform <li.sc so set in the ribbon- 
 hke figure that its cireumferencv is not pig- 
 
 7!) 
 
 mented within the band prop<>r but is con- 
 tinuous with the tinte,! bonlers them.selves 
 In some indivi.luals there are traces of a 
 groove 111 the retinal l)aiid. 
 
 The p.rten in shape resembles that of the 
 Iludsonian Curlew. It has ^l sausnge-like 
 convohitions; its fringed keel being prolonged 
 at the inferior extremity into a spinous ,)rocess 
 that (not shown in the cuts) follows the eon- 
 •avify of the eyeball and almost reaches the 
 margin of the lens. One-third of the coils 
 present a concave surface to the posterior free 
 margin. 
 
 The infiilapapillary angle is about .50°. 
 In prepared specimens lh<- eyeball is ovoid 
 with axes 8:9. In .some individuals, also 
 there are traces of a groove in tlu- n'tinal band! 
 IIiDsoNux Clrlew. \„menii,>, hudmni- 
 cus. (Figs. H5 and 88; macroscopic view ) 
 The background of this biril's eve shows a 
 hroad, grayisli hand, with evenlv dotted bor- 
 ders, tliat extends almost horizontallv across 
 three-fourths of the visible fundus'. It is 
 equally divided throughout its whoh' length 
 into two parts by a plainly marked line. 
 
 The major axis of the papilla i)roj.-ctcd 
 towards the band (h'seribcs with the latter an 
 angle of 50". It bi.sects it half the axial l.-n-th 
 from the erater-lik<; fovea. 
 
 The pectin, carrot-s]iap<-d from above, has 
 a fringed cap covering its upper free border 
 It exhil)its 3i convolutions, the spaces be- 
 tween the middle ten being deep enough lo 
 allow a glimpse of the oi)lic margins, that 
 are elsewhere completely covered. The 
 i>hi( k, free margin corresponds in shape to the 
 pi-etinate body, being quite liroad below, 
 narrow and pointed above. Its inferior third 
 IS prolonged (into the vitreous) in the shape of 
 two conical elevations and a long, single 
 notched spine. The crest graduallv slop.'s 
 from behind forward so that tl,e posterior- 
 eoils air the longest. Two-thirds of the coils 
 "face"' forward. 
 
 Ghkateh YELLow-i.K(i.s. Tolann.^ nulnno- 
 leucus. (Figs. 114 and 87; macroscopic 
 view.) In this species ;i broad rctinul liuiid. 
 faintly depicted with pigment lines, cMends 
 across Ih.- entire visible fiehl, its nasal half 
 being divided by a double-dotted line that 
 
80 
 
 THE FUNDUS OCULI OF BIRD? 
 
 •■n.ls lit tlic pi^'iuontcd rircimiferonfe of tho 
 ciniiliir nuifiiln. 
 
 Til.' mnriihr rajion, twice us wi.lo as llii- 
 siim.iiiKlinj.' I.an.l, prt-sonts a larj;.-, trnlral 
 fovea. 
 
 The prrlen has much tho same shajw as in 
 Squatiirola; it is, however, a little larger, aiuj 
 has :!■» eciivohilions. The niediimi size.] 
 coils, loiijjer Uallerj as one ai)|)roaehes tho 
 post.TJor free margin, ar<- cai)i)e(i hy a deep, 
 irn'KnIar. [.arlially serrated. iidg<'-iike crest 
 that lernnii.iles posteriorly in a sh^rp point; 
 anteriorly the erest heeomcs much narrower, 
 anil ends in a tapering Irian^'ie. 
 
 The optic nilnnirr is (at its middle) seen 
 through th<- inlerrnpted coils of the peeten; 
 and tiie infuhipapillary angle, niach- l.y its 
 projecte.1 major axis and the lower margin of 
 the retinal hand is hetween 4.")" and .^O". 
 The shape of this eyehall is oval, 10x11. 
 Stoxi; ri.()\|.:i(. (Edicnmux sculopux. 
 Tlio fundus appearances (left eye, erect im- 
 age) of this nocturnal hird are depicted in 
 Plate XVII, ,,age 1:J7. 
 
 The cyeground is a warm brown or choco- 
 late color, rather (hrply pigmented near the 
 periphery and cov<'red with orange-red dots 
 that are very densely packed on tho ui)per 
 half of the fundus. Uelow the optic entrance 
 are numerous choroidal vessels running paral- 
 lel with and on either side of the papilla. 
 
 The iiKuiiht is diir.iilt to distinguish and is 
 not clearly defin..i vmI, lue ophthalmoscope. 
 It IS situated ahove the sui)erior end of tlio 
 disc on its inner or nasnl side, and about half 
 the apparent length of the peeten from the 
 upper end. 
 
 The fundus coloring is slightly d.irkcr in 
 the macular area, which is surrounded by » 
 rellex ring, [)ale gray in color, in the form' of 
 very minute lines radiating from its margins. 
 There are, also, a few radiations near the 
 Jorfn ctntmli.i. 
 
 The papilla is white, oval in shape, fringed 
 ull round with <lense black pigment, and a 
 few gray, opatpie nerve fibres are seen on 
 either .side of it. 
 
 The p,T/cii is \ery large and projects well 
 into the vitreous. It is of unusual shai)e, 
 rather narrow, but when examined from al>ove 
 
 look.s ns if it bad been compressed and flat- 
 tened on both sides, with a narrow edge above. 
 Great Hi stahii. Otis tarda. (Figs. H7 
 and 90.) The macroscopic reproduction of 
 this barkgrmind shows a narrow line of pig- 
 ment, rei)resenting the usual retinal baud, 
 which extends horizontally across the central 
 two-thirds of the visible fundus. At almost 
 Its exact middle is an incompletely oval area 
 encircle<l by a ring of pigment grains. A dark 
 spot (fovea) more or less surrounded by 
 black dots, occupies the centre of this crater- 
 like space. 
 
 The large and compact peeten forms a very 
 regular, oval figure who.se extremities appear 
 to be of practically the .sanu- shajR- and size. 
 II is made up of about 42 convolutions united 
 in a crest that, from above, takes on tho aji- 
 pearance of a fisherman's (cork) flojiter. The 
 peeten in this .species is remarkable because 
 of the small number and large size of its folds, 
 because the central five of these are the long- 
 est, and because the middle half of the keel, 
 or crest, is projected as a tall cone into the 
 vitreous. 
 
 Tho major axis of this optic disc subtends 
 an infulapapillarj- angle of 70= with the linear 
 retinal band. 
 
 Gruifonnes 
 Kagi-. Rhinochetus jubatits. In many re- 
 spects the eyeground of this bird, as seen by 
 the ophthalmoscoiMj. presents apjx-arances 
 (see I'late XVIII, page 137) similar to the 
 fundus pictures (Plate XVII, page 137) of the 
 Australian Stone Tlover, except that the 
 former has a gray area above the disc, instead 
 of ,1 n-d and brown one. The drawing is of 
 the right e.\e, as seen b.y the erect image. 
 
 Tho background is, in general, covered with 
 a mass of minute dots that are grav in the 
 upiKT half of the fundus and orange below. 
 The lower sectors of the fundus are stippled 
 with pigment. Choroidal ve.s.sels are numer- 
 ous and run in rather straight, vertical linos 
 on both sides of the optic disc. They are 
 tlull-orange in color. 
 
 The foiea is shown towards tho anterior or 
 nasal half of the retina, and ap|M-ars as a 
 round hole or crater-like depression, brown in 
 color, which rcHects a grayish sheen from its 
 
 ^' ^^^JTF^^^JT 
 
 11 rs 
 
 ,i7.iV,f*j.:^.>'; 
 
THE FUNDUS APPEARANCES 
 
 center. A narrow gray cirilo or reflex ring 
 surrounds this pit. 
 
 The optic di-ic hus its central portion iippar- 
 ently stippled with bright ornnge-red dots, 
 while its margin is fringed with course, white 
 fibres, that are also studded will, hrown pig- 
 ment dots esjK'cially near the outer border. 
 The peclen is of the usual deep, chocolate- 
 brown color, rather narrow where it joins the 
 disc but becoming much thicker and more 
 massive as it projects into the vitreous towards 
 the lens. 
 
 BiiAZiLfAX Seriem.\. Cariama crhlala. 
 This species presents an ophllialmoscopic 
 picture of the right eye, erect image, that is 
 reprfxluced as Plate XIX, page 139. The 
 dominant color of the fundus oculi is a dull- 
 dral). Over the lower quadrants of the 
 eyeground run rather straight, dull-red, cho- 
 roidal capillaries that fade away as they 
 n-ach the upfM>r half of the field. This region 
 is also shot with a greenish-blue muslin-like 
 film, which is probably a reflection by the 
 retina of light rays from the ojihthalnioscopic 
 mirror. Above the end of the disc is a small, 
 round depression, quite clear of any reflex. 
 To the inner or beak side of the eye is the 
 circular macula, whose diameter is about 
 three limes that of the cavity at the end of the 
 disc. The center of the larger circle is quite 
 clear, with the exception of a bright shinmier, 
 such as is sometimes seen about the human 
 fovea. The circumference of this circle is 
 very sharply defined, and has a bright ring 
 around it of glistening white. 
 
 The nptic disc appears as a long, white 
 oval, with irregular margins. 
 
 The black-brown, corrugateil fxrlen is very 
 large and long; it extends into the vitreous 
 and almost touches the lens with its cluli- 
 shaped terminal. Very fine opaque nerve 
 fibres radiate at regular intervals from the 
 whole papillary circumference. 
 
 In two ey<'s of this bird examined l)y the 
 writer there were, in addition to the appear- 
 ances just detailed, several .scattered, red- 
 dish-brown dejiosits, very slightly pigmented, 
 111 the choroid. These were found in an 
 individual captive in the Uronx Park for four 
 or five years, and were probably pathological. 
 
 IN VARIOUS ORDERS OF BIRDS 81 
 
 Ardeifonnes 
 Amehican Bi,a( k-chow.ved Nioiit Heron. 
 Syvticorax ni/rliconix nvtiiin. (Figs. 9< 
 and \i9; macroscopic view.) 
 
 There were no definite, naked-eve indica- 
 tions of a fovea in the individuals 'examined. 
 The pertni, more pointed at its surM-rior 
 extremity, exhibits 20 convolutions, .so .sepa- 
 rated that a view of the disc borders is here 
 and there obtained. The |H-ctinate coils are 
 united by a narrow, cord-like crest that ex- 
 tends on the same plane and in a straight line 
 (except that at its middle point it is slightly 
 high.T) along the upiier free border from one 
 extremity to the other. The coils do not 
 differ much in length. 
 
 EiHOPEAN- \ui,iT IIehon. \ycHcorax 
 nychcorax. Seen with the ophthalmoscope 
 the rycgroHud (.see Plate XX, page 13!)j is 
 dull gray, covered with grayish-while dots. 
 The lower part of the fundus exhil)its a num- 
 ber of faint, reddish choroidal bloodvessels, 
 that run in a vertical direction, and who.se 
 disposition is .similar to the capillaries .seen 
 in the fundus of the Boatbill, depicted in 
 Plate XXII, page 141. 
 
 The optic dine is long, but of medium width, 
 with both extremities roundel. Its eenter 
 is orange-red and covered with minute, brown 
 pigment dots. 
 
 The pccten is deep brown and its outlines 
 are well defined the whole length of the 
 papilla. Very thin grayish radiations extend 
 from the upper two-thirds of the oj)lic 
 entrance. 
 
 The macula is situated quite clo.sc to (and 
 towards the upper nasal asix'ct of) tlie di.sc. 
 It is surrounded l)y an outer ring of whitish 
 lines: then, towards its eentre is a zone re- 
 sembling the surrounding, puiiclated retina. 
 In its exact centre is a small fovea composed 
 of gray-white strife. 
 
 (Jkeat White Heron. Anica occidnitulin. 
 The individual examined by the writer had 
 been in captivity at tlu' Bronx Park for .sev- 
 eral years and was slightly myopic. The eye- 
 groun<ls of both eyes appeared i.lentieai and 
 the ocular organs were normal. The pupil 
 contracts under the strong light „f tli<' oph- 
 thalnio.scopie mirror to medium size. 
 
Si 
 
 THE FUNDUS OCULI OF BIRDS 
 
 ^-i«. H9. Blaok-crowned Xi.l.t Iloron (X.cticora. nyrHroras n^u.) xfi 
 Macro«x,pic Appearances of the FuBdus Oculi in the Pr«erved Kye. of Bird,. 
 
 7/ T.V'-^-' - ■* 
 
THE FrXDUS API'KAHANCES IN VAHIOIS OHDEHS OF BIHDS 
 
 I 
 
 Til.- .Ic.iiiiniint rolnr of the hm-kgrnu,nl is 
 liKhl-nd.lisli or l.r(iwnisl|.«ray ami has appar- 
 I'lilly a Kramilar surface. 
 
 Tlif impilh is white, aliiH.sl .•iilircly <ov- 
 .•r<'<l hy tin- iM'ctoii and seems shorter than in 
 most l>ir(ls. 
 
 The piclrn is imiisiinlly hirge; only its fri-<. 
 en.J, whieh is lilunt and rounch-.l, (an he oiit- 
 line.l with the mirror. There is no «el|. 
 tiefineil macular region. 
 
 Amkiik ».v Va.uf.T. llrrodian r</r,l.'.,. \ 
 young adult was examined |,v ||„. „ritcr 
 in the Bronx Park. The dominant color of 
 the fundus in this species is n clear, hright, 
 .steel-gray. 
 
 The pirtni, an ohiong with rounded ends, 
 <'<.ver.s most of the optic disc, whose white 
 Imrder can he seen only on the outer si.le. 
 Stnie. composed t.f whitish opaque nerve 
 fibres, radiate from the circumference at 
 regular distances from each other. 
 
 Amkkicav Uittkhn. liotaum.t Imtigimi- 
 "ii.". (Figs. 1-28 and 91. j This fundus when 
 seen hy the naked eye and in prepared speci- 
 mens, .show.s two macular regionn with thiir 
 fomr. Till' forea uasulin ~ a. large dot .sur- 
 nuinded hy a nebular ring — just above and 
 slight I., to the nfi.sal side of the superior 
 extrennty of the ix>cU!i. Temple-wards and 
 almost at the periphery of the visible back- 
 ground i.s the forea temporalix — a less dis- 
 tinct area, also depicted as a central spot sur- 
 rounded by « ring of pigment grains. Allow- 
 ing for the concavity of the eyeball the two 
 macuhe seem separated (in the figure) by 
 about two-thirds the length of the optic disc. 
 The coralliforni, fenestrated structure of 
 the pectcn is nmde up of 28 narrow convolu- 
 tions that are .separated at their upper free 
 niargins .so as to allow, here and there, a good 
 view of the pigment-dotted surface cf th - 
 opticus. There are three (,une(|ually) .short ai..- 
 eleven ■ qually) long double (oils joined 
 above by a narrow but uniform crest. 
 
 EiKOPK.w Bittern. Botuuru.i stellaris. 
 The left fundus oculi of this species is depicted 
 in Plate XXI, page 141 of this work. 
 
 Tht eyeground, tuostly mouse-coloreej 
 shaaing to yellow, is .sprinkle<l with small, 
 dull-white dots. 
 
 83 
 
 Almost immediately above the upjHr end 
 of the oplic nerve entrance and towards the 
 nasal side of the disc is the macular ana. The 
 fundal dots at this point are much .luller in 
 lone and incline towards a dull, bulf coh.r. 
 The region of the macula, enclosed by two 
 cirehs, one within the other, is nlso'char- 
 acterizcd by the presence of very short, 
 bright, bluish-green lines radiating from the 
 center of the fovea. These striiilious are very 
 brilliant an<l are easily .se<>n by the aid of the 
 ophthalmos<'o;H-. 
 
 The nptic dine is ovoi<l, blunt at its upper 
 extremity, ami appears as if its longer nmr- 
 gnis descril)e a .series of small curves corre- 
 sponding to the folds of the p<>cten. The 
 disc on either side of the root of the peclen 
 is dull-brown; near by are small, orange-red 
 choroidal capillaries. The papillary nuirgins 
 are quile white and, in contrast with the 
 shadow cast upon the neighboring field by the 
 dark i)ecten, the disc stands out in .sharp con- 
 tour. Kxleudiiig a short distance over the 
 fundi and about the oplic disc are a few 
 opa(|Ue nerve fibres. The i)ecten. con- 
 voluted, with .serrated margins, and of the 
 usual chocolate-brown color, extends below 
 the lower end of the optic disc, and is plainly 
 visible. It does not project far into the 
 cavity of the vitreous. 
 
 Mo.vT-uiLLKD Night Heuon. Cancroma 
 i-. c:}/-tiria. The eyeground of this Central 
 .Vmerican species is represented by Plate XXII, 
 page 141, and depicts the left eye 1... '. . ,, ,t' 
 image. The prevailing coloMif.'f, of *ii.- 'va-k- 
 ground is dull-red, covered vvi'ii ocs-in -re { 
 dots. These punctate deposits are ir>!. r- 
 mixed on the upi)er half of the fundus wi;f, 
 smaller ami brighter dots of a gr.u . ■ lone. 
 On the lower half and on each .side oi'tl. ■ ; l.t 
 nerve are a few orange-red choroidal . jipil- 
 lary vessels, that run in a vertical dirclion, 
 parallel to the long a.xis of the disc. 
 
 The macula is situated towards the nasa. 
 side of the nerve head. This sensitive area is 
 rather brighter in color than the surrounding 
 field, and several white dots arc included in it. 
 These small dots, however, are noticeable 
 only when the light of the mirror is reflected 
 on the region in certain directions. Kather 
 
 )m^msMmkf:mm 
 
84 
 
 « ImKhl irrfRularan,! linear n-H.-.x surround. 
 t^^K• nmeulnr r-Kmn. whUh i» v.-ry «.„sitiv,. ,„ 
 
 Tlu-ro i, « \oug, narrow p„p>ll„ with roun.l,.,| 
 .•xtrom.tu.. It „p,H.„r, „, .f j^ „.^.^,. ,,„,,, 
 l«.so.l of short, whit., (il.rc-s. ,urroun.hnK an 
 '>ranK.-.r.-.| n-ntor .ovr..,! with n.inut... .lark- 
 l.rown ,„«„,..„, ,,r,i,„ (^at f„r,„ „ ...twork 
 <•^^^ the- w^hol.. rt-,1 ar,.a. Kxtcn.linR from 
 
 onchs.,, of th,. disc across the n-linaar.. a 
 few dull-Kruy, opaque nerve fibres. 
 
 The ;v-r/.„ can l.e tram! the whole lenRth 
 "f the disc; ,t i., ,|„rk l.rown in color and 
 groove.! spirally like a corkscrew. It d.H-s 
 ""I <.piHN.r lo come far forwar.l towards the 
 l'-"Y "-l "s union with the nervehead can 
 readily Ik. traeed. The peCen and its im- 
 .ned|ate relations remind one of the fundus 
 oculi of the Bitterns. 
 
 r.u.HHV I„,H. rirgaJi, falcinellu.,. U 
 will he seen on examiniuK Plate XXIII. paue 
 1 tJ. representiuK th.- left fundus o,uli of this 
 HjK-<'i,-,s, the general coloration is l.hie-Krav 
 the .-ye^round Ik-Iuk covered with a nel.ula of 
 nnnu te. pale-^ray dots. Riving i, „ ,.H|ii,.„( 
 Kra.N tone when lighted up l.y the ravs from 
 tne o()litlialnioscoi)ic mirror. 
 
 Towanls the lower part of the fundus and 
 o. bo h sides of the optic disc, hut parallel 
 With It, are many oranKe-red <horoidal capil- 
 aries; they are especially numerous l,elow 
 he optic nerve and suffuse the ,>,.ri,,heral 
 l.ack^roun.1 with an oran^e-pink glow 
 
 tJny one sensitive area is swn. This 
 
 m«c«/«r .,,,.„ is loeated above the disc on the 
 nasal side of the nerve. In the cente- of H,,. 
 area is a small, while, round dot. sum..m,l, ,1 
 by a brilliant blue-Krt.M, reflex, like the sImtu 
 
 on floss silk. It is probably due to the plav 
 of l.Kht on the fine fibres radiating- from the 
 center of the fovea. 
 
 The„p^V.rf,> looks as if i( ,.,.,., „ „,„,^ 
 "f coarse white fibres; it is sm.iiar in slia,K. 
 «> the papilla of the .Spoonbill, but it can 
 'e traccl only for about half its le.,«th 
 the lower part beiuK obscured by 'he mas- 
 sive club-sha,,ed peclen. The di.'- is bor- 
 dered with black pigment whi.h gives the 
 appearance of a sha.low cast on the eve- 
 ground. This organ is of the usual chocolate- 
 
 TIIE FrXDl'S OtlXl (»F BIHDs 
 
 brown color and project,, well forwar.! towards 
 tne lens. 
 
 A large number of semi-transluceni nerve 
 hlM-rs ra.jiatc fr.mi the margin, ,.f Ihe opliV 
 nerve on „1| .si.les; they exten.l a.ross the 
 ehoroidal vessels, ami finally vanish alto- 
 gellier in the fiindal |)eriphery. 
 
 AUKHI. AN Jabiku. Mycl,ria amerirana. 
 The fundus of the lef, eye is .lepi..ted in 
 I ate\\I\.p,^„. ,4;, by the direct method. 
 Iho !„nrral coloration is « slate-grav. the 
 whole eyegroun.l U-ing ,,uit,- uniformlv 
 sprinklci with small but varinuslv si/,.,i 
 »Wutedots. In the upper and nasal ."luadranl 
 of the pict.m- is the small, single macula, an 
 an-a darker than the surrounding parts, whose 
 exact centre shows a round white dot - the 
 Mca. In the lower two-thirds of the (iri.l 
 are seen numerous, plainly niarkcl ,|,„roi.|,d 
 vess,.|s (hat extend the whole length .,f the 
 pecten. conv.-rging .somewhat towards th.- 
 p.>sterior a^jM-ct of its base. About l»o. 
 thirds of th,- long an.l rather broad ncrn-l„a,l 
 is plainly visible, e.xc«.pt the central portion, 
 which IS pa. tly obscur..<l I y the pcrfn,. This 
 arge, black-brown organ, divided into I.-, 
 arg.- and .s,.veral much smaller double folds 
 termmates above as a thin, dark rod The 
 dis,. IS fringed by black pigment grains, an.l 
 from Its hiteral margins proj,.ct a mimlHr of 
 short, faint, whitish lin.-s. 
 
 Si'.).)VBrLL. Plalolca leucor.nlia. T|,.. ,.„| 
 or.-.l fundus view (see Plate XX \', pag,. I »-,) 
 is of th,- eret-t image, left .-ye. In «.,,era| 
 lie .-olor of the cy,gro,md is .l.-ei.l.-.llv graN- 
 "•'•o"'inK brownish f.,war.|s th.- ,H.i'ip|„.rv.' 
 It will be noted that the entire fun.lus is 
 t '"ekly sprinkh-d with minul... imguiarlv 
 sh...,H-,l gray-whit., dots, th;.t app,.ar mon- 
 distinct about the macular ivgion. 
 
 At the fovea, where th..y an- briiliaiil 
 
 wh, e, tlK.y «„• still more .losely p,....k,.,J. 
 
 Uith the .>phtlialmoscop,. th,- fov,.al r.gion 
 
 apiH-ars to be sunk.-n bel,.w its surrouml- 
 
 iiips, andtobe.-ne!.,s,.din.. pal.., g,,..,.i,h 
 
 reflex) ring that ,, of oval slia,K. with its 
 
 long axis horizontal. Ju.lging from the 
 
 e r..ct on the bird when the direct light from 
 
 tlie mirror is thrown upon it, this ari-a is 
 
 extremely sensitive to light. 
 
 .^BSiSIS^s?^ 
 
3 
 
 I 
 
 TIIK FINDCS APPKAHA.VCES IN VAHIOIS OHDIIHS OF HIHI» 
 
 Tlir <>|iii<' ri.-rvi -.iilrntKr i, n U,un. imrniw 
 oval, iiihI |irf,.iilN « l,rilli,,til ulijlr ,i|.|Hnr- 
 iiiKf. Wjir its u|.|KT <-ri<l iirv srv.nil choroi- 
 •lal <ii|.ill,iri.-s of II iml,.. j;,,|,|,.„.y,.||„„. ,.„|„r. 
 I'anill.l I., til.- liiiiK axis of th.- li.rvr-lnii.| in 
 iiiiotlicr flHiiKali-.l iiiasN of uliji, (il.r,., • 
 (iilMio,t likf a vcoiid o|ili,' ,1,., , liiiviiiK its 
 
 r.'iil.T Mi|.|)!r.| will, tin,, pii; „t .lot,, ali.l 
 
 .•M.'iMJinK a.n.xs ||„ ,y,.Kro,iiHl. Ha.lialii,^ 
 from lh<- .inimif.Ti'iH,- of ||„' papilla on,- 
 x'fs a miijiiIkt of faint. Inin.lii,,.|it fil.rcs, 
 (TosMiiK lhc> small whit,. ariM on tlir iia.al' 
 side of tli<> n«T\f, 
 
 The /).(7</( cl(«-, n,i| proji.cl very far 
 forwar.l into tlit- vilrroiis; it is dark «rav- 
 l-rown and app,.ar> to I,,- compN-tcly fovt-ml 
 with a iiiindM.r of waiiy proliilMTanc.'s. 
 Il app,ars to l„. atlaolinl to tli<' who!,- l.nKlIi 
 <»r III,- .-..ntrr of ||„. diM', that is siippl,.,! 
 with fine, ri-d <|ots. 
 
 Anserifonnes 
 Hl.A,K-HKM.iKi) TliFi: DtrK. Dnulro- 
 <!/!i,ia <iiit>imii„tl.t. Till- fundus appearances, 
 as r(-v(-ali-d liy the oph||ialniosi-,)p<- in six 
 i-yi.- of three indivi,liiaN, are d,-pi,|,-,i as 
 I'iale \X\I, pa>.'e H.j. Five normal eye- 
 «roiin,N wen- i,lenli<;il; ||ie sivlh exhiliiled a 
 e,)liKenilal .h-leel of the nerve-h<ad whieli 
 t-iilirely ehan«ed the fundal pi<tiire. 
 
 Tlie/»»(/)(.v ,)(.;//(■ of 111,. Tree Duck is colored 
 a litflit fawn, besprinkh-d with minute, white 
 •lots, that Klislen wh,-ii a strong lijfht from 
 the mirror is thrown upon them. On ,.a,li 
 side of th,- papilla is s(-<-n a iiunil(er of ihoini- 
 -lal .aiiillaries. Iirinht orange in color and 
 rather strai^rhl. 
 
 The i>i)lic ,//.«,. is also orange-red aloiij; its 
 major axis, lliis o-ntral zone In in^ stippled 
 all over wilh a n<-twork of fin,- j.lack .hds. 
 Tin- circumft.rence of the <lisc is friiifjt-d with 
 while lilires. 
 
 The dark-hrown ixclcii arisi-s, as usual, 
 from 111,- whol,. leiiKlh of ||i,. disc. Viewe,l 
 from aliov,- it .seems very thin and twiste.i, 
 
 • \\ IhIIkt llii> \h u iiDriiial conditiori or un anomaly 
 of dcvilopm.nt raiini.t Ih.- d.-finiielv staid without 
 un ,\.iiiiiMalion of additional s|K-«iimns, but il was 
 Iir<-.-..iil in both cyt-s of the individual undur uon- 
 sideratiuu. 
 
 M 
 
 like a corks,r.-w. A few <ipa.|uc n.-rve 
 fil.res exieii.l for a ,|iort ,li>lanc.. and at 
 riK'lil aii(,'l,-s to ||„. ,|i„. „„ ,.i||„.r ,j,|,, .,.||^. 
 il|)|H-r part of III.- fiiinjiis is almost ol„eiir,-,l 
 l.y iiiimi-roii, niiniil,-, l.rillianl, whil,- dot, 
 Allhouk'h ll.-a.l noli,.,-,! Ihal wli.,, he f,M-Us.-.| 
 the l.riKJil liKhi of ih,. mirror „„ the upp.i- 
 <|uadranls of |h,. fun.lns ih,. I)u,.k, us.-,| 
 th.ir iiK-mhrana nic-litan- nior,- fre,|ii,nlh 
 than Usual he lould not ,liseovi.r any \\r\\- 
 detineil s,.n-iliv,- ar,-a. 
 
 Hl.l K-WIN,.KI) TkaL. Q>„rqi,al„l„ ,li.i. 
 fori. Th,- >;,-n<-ral iipp,-,iriii.<,- of this liinl's 
 ey.Kroiind ,l,.„|y approaches thai ,if tin- 
 Mallard. Th,- lol|^.r. „v,,i,| pa|,illa is di,pos,,l 
 with its inajoi axis at ri^lil aiiKh-s t,, U,,- 
 iipjH.r niandihli 
 
 Mandaiiin 1)1, k. Air ;;(il,rir,il„l,i. In 
 examinini; Ih,- .•y.->;rounil of this >p,.,.i,., H,,. 
 wril.'r fouiKJ |l,.,i th,. lij;hl ,,f Ih,. ophlhal- 
 inoscopi,. mirror, when project,-,! on H,,- 
 ey.-s ,lir,-.ily from the front, ilhimin.il,.,, 
 roiiijhly >p,-akin>.'. about om--si\ili of ,.,„.i,' 
 field. 
 
 Till- prevailiiif,' ,.o|,,r ,,f ih,. ba, kurouii,! 
 is lijilil, «ray-browii, str,-ak<-d with faintly 
 marked ,h,iroi,lal cai>illari,-s, thai ar,'-. 
 liow,-v.-r, con(in,-d to Ih,- na-al si,h- of ih," 
 ilis,-. 
 
 The direct nielho,! shows a v,.rli,..illv 
 plai,.(l ,)/)//,. rnlniiicr. that appears to slrehh 
 almost ov,r Ih,- whole fundus. The fi.jd on 
 I lie out,r asp,-ct of the dis,- seems t,) be 
 siip,-rficially roiiKliem-d or Kranul.ir. Tlu-re 
 lire no railialin;; opa(|ue n,-rve-hbr.s or con- 
 ceiiiri, rellex rinj;s visibl,- wilh lh<- miri-or. 
 
 The iKctcn is comparatively small, doe, not 
 entirely covi-r the dis,- and picsents fr,iiii 
 iibov,- ilowiiward a retir ulaltd appeaMiiei-. 
 M.\Lr,Ani) I)i < K. A.iii.s homi.t. The 
 Ken,-ral (■(iloniUnii ,>/ the fiiiidii.i of this bird is 
 Kray-n-d. Th,- „/)//,• m^rie vntranrc is much 
 longer than in most species, extending in a 
 p<-rpeiidiciiiar fashion across the baekj;round; 
 it is in no place obscured or entirely hid by 
 the pectea. The papilla apjiears to be 
 attached for tlir<-o-fourths of its course to 
 the latter, which arises in partially trans- 
 lucent, veil-like folds and extends 1.. the 
 posterior surface of the lens. Xo concentric 
 
 ■^ww 
 
86 
 
 THE FUXDUS OCULI OF BIRDS 
 
 <ir(lfs of ()|)ii(nic iicrvi- fibres are vislMe. 
 The whole haeksround, inehidiriK the dise, 
 seeriis to hv dotted witli many piinclate 
 |iit;tiieiit grains. 
 
 Canada (ioosi:. Braiila rdnnihnniK. The 
 iiidivi(hial.s of this s]K'cies examined hy tlie 
 writer liad lieen (h)mestieateil in the JJronx 
 I'ark for .several years hut under con<iitions 
 approaching their usual hal)itat. 
 
 Tile appearances of X\w fundiis ociili were 
 l)raetiealiy identical in all the specimens 
 exannned, and are similar to those of the 
 Mallard. The concentric arrangement of 
 Ihe o|)tic fihres in Anas is lacking in the 
 Brant, while the latter has the larger pecfen. 
 Although the prcfen is rather large, the 
 outlines of the vertically oval, yellowish- 
 white papilla are visible throughout. 
 
 Blie (Snow) (ioo.sE. Chen ccendesccnu. 
 Plate XXVII, page 147, reproduces the fund- 
 us appearances of two individuals examined by 
 Mr. Head and of another seen by the writer. 
 The backgrounds were the same in all. 
 The predominant funded color is ii distinct 
 fawn, sprinkled with small, round, orange- 
 I)ink dots of irregular shape and size. Run- 
 ning vertically past and parallel with the 
 optic papilla, over the lower half of the 
 fundus, are numerous, straight, orange-red, 
 choroidal capillaries. 
 
 The/o(T« is probably indicated by a small, 
 glistening white dot above the end of the disc 
 on the nasal side. This small, punctate 
 deposit nearly disappears when the light 
 from the mirror is turned in certain directions. 
 An inconstant, bright-green reflex is .lotice- 
 able in this part of the eye, and there is a 
 decided photophobia when the ophthal- 
 moscopic light is flashed upon the region 
 of the supposed macula. Moreover, by 
 careful focusing the circumference of the 
 fovjal (?) (lot shows a small brown rim, like 
 th.- sides of a crater. However, the light 
 from the mirror does not reveal any actual 
 depression; the cyeground appears level 
 throughout and is uniform both in color and 
 texture. 
 
 iThe optic nerve-head is boat-shaped, tinted 
 orange along its central zone and shows a 
 narrow rim of coarse opaque nerve fibres 
 
 that form a fringe about its circumference. 
 This orange centre is sprinkled with numer- 
 ous minute, dark-brown or black dots. A 
 few gray opaque nerve fibres arise from the 
 disc margins, and cross tlie fundus horizon- 
 tally. The pecten, of corkscrew shape, runs 
 the whole length of the disc and comes 
 well into the vitreous. 
 
 Lessek S.vovv Goose. Chen hyperborcens. 
 (Figs. 93 and 131.) There is, judging from a 
 naked-eye survey of this fundus, a grayish 
 but well-defined, rather narrow, retinul 
 band, devoid of pigment, that runs obliquely 
 through the center of the field from one 
 periphery to the other. It is more definitely 
 outlined by pigment grains on its inferior 
 than on its upper margin, especially where 
 it traverses the nasal half of its course. 
 About its middle point is the single macular 
 region and fovea — & short but regular line of 
 pigment in the center of an enlargement 
 of the band. 
 
 The large, shoe-shaped pecten is com- 
 posed of 24 heavy, compact convolutions 
 that terminate in a cigar-shaped superior 
 and a triangular inferior extremity. The 
 conical crest of the upper free border is 
 wide for three-fourths of its entire length. 
 It terminates in a thin, corkscrew process 
 before it reaches the tip of the upper con- 
 volution, which almost touches the reti-ial 
 band, with which the (projected) major 
 axis of the nerve-head describes a right 
 angle. The convolutions decrease pari passu 
 in size from behind forward, all the coils 
 inclining towards the lower end of the disc. 
 
 Phoenicopteriformes 
 
 Common Old-would Flamingo. Phoe- 
 nicopterus roseus. (Figs. 94 and 115; macro- 
 scopic view.) This ocular background shows 
 a small but compact pentcn, whose 18 
 convolutions are (apparently) drawn towards 
 the center of the organ above by a deep, 
 cigar-shaped crest, so that the niarsupium 
 resembles, when viewed laterally, a truncated 
 cone. 
 
 Stretching obliquely across the fundus is a 
 light-colored, retinal band of medium width, 
 which ends abruptly just before it reaches 
 
THE FUNDUS APPEARANCES IN \ARIOUS ORDERS OF BIRDS 87 
 
 ' r 
 
 Fig. 131, Ia^sscf Snow Goose (Chen hyperborea) X9. 
 Macroscopic Appearances of the Fundus Oculi in the Preserved Eyes of Birds. 
 
88 
 
 THE FUNDUS OCULI OF BIRDS 
 
 tiio temporal Iwrdcr of llio field. Two lines 
 of pigment dots — the one at the nasal end 
 more plainly marked and eaeli as long as 
 the disc — divide the terminals of the hand 
 into two narrow spaces. The lower margin 
 of the band is drawn with nunierons niinnte 
 pigment grains that are sparsely supplied 
 to the upper liorder except at its nasal end. 
 A third line of pigment, deeper in color than 
 the other two. atu! about as long as the 
 papilla is wide, indicates the middle point 
 of the hand somewhat nearer its temporal 
 end. At this point the hand becomes slight- 
 ly broader, especially below. In the centre 
 of this shortest line the pigmentation is 
 somewhat pronounced, but an outline of thi 
 ordinary slil-like forea within a retinal band 
 is not here well developed. 
 
 An extension of the long diameter of the 
 papilla to meet the lower border of the retinal 
 band, makes with it an infulapapillary angle 
 of CJ°. 
 
 Pelecanifonnes 
 
 Cormorant. Phalacrocorax earho. The 
 fundus view shown in Plate XXVIII, page 
 147, of this work, represents the ophthalmo- 
 scopic examination of eight eyes of four indi- 
 viduals. Two were tame birds, the others 
 were freshly caught, but their eyegrounds were 
 identical. The drawing presents the appear- 
 ances in \hi left eye by the direct image. 
 
 The fundus oculi is mostly of a slate- 
 gray color, uniforndy sprinkled with numer- 
 ous, minute white dots, closely packed 
 together. Running chiefly parallel with the 
 long axis of t!ie optic disc are several rather 
 straight, orange-red choroidal capillaries, 
 that extend the whole length of the papilla 
 and beyond its inferior extremity. 
 
 The macular area is seen a little al)ove the 
 upper end of the optic disc and on the nasal 
 side of the nerve. The fovea aiJjH-ars as a 
 reflex image of a few short, bright, white lines 
 surrounded by a narrow and similar ring. 
 
 The optic dine gives the impression that 
 it is composed of a mass of very white, 
 cotton-like fibres, disposed iis a fringe all 
 about the papillary margin. The central 
 area of the disc, especially on each side of 
 the root of the pecten is orange-red, 
 
 stippled with minute, brown pigment 
 grains. Perpendicular to the papillary mar- 
 gins are a few short, fine opaciue nerve 
 fibres, that run towards and are finally lost 
 in the peripheral eyeground. 
 
 The pecten is rather long and of the usual 
 chocolate-brown tint; it is much narrower 
 than usual on the upper half of the <lise, 
 and comes well forward into the vitreous 
 humor, extending behind the margin of the 
 pupil. 
 
 Fallahonf. C'orm(.rant. Phalacrocorax 
 dilophu.1 albociliatiiK. An adult individual of 
 this species (while dying) was examined 
 by the writer in an open boat in San Diego 
 Bay, California. An ophthalmoscopic view 
 was obtained under these difficulties, and 
 is consequently incomplete. However, the 
 writer saw through dilated pupils that the 
 fundus was gray-black and uniformly dotted 
 throughout. The pecten was easily seen, 
 but not well enough to count or accurately 
 describe the arrangement of its plications. 
 
 Brandt Cormorant. Phalacrocorax pc- 
 nicillatun. (Figs. 95 and 130.) This fundus 
 ocuii, when viewed with the naked eye, in pre- 
 pared specimens, shows a broad, gray baud 
 depicted in the black and white drawing as 
 extending in a rather oblique direction from 
 the nasal periphery of the field to a point im- 
 mediately above the supt ior end of the pa- 
 pilla. Here, just before it terminates, the 
 band widens and develops into an oval area 
 with a large central, black dot, crowned by 
 minute and scattered pigment grains. This 
 macular area is located about the width of the 
 minor axis of the optic disc from the upper ex- 
 tremity of the latter. 
 
 [In the temporal m"rein of the black-and- 
 white drawing is a si mark; this is 7iot a 
 second fovea but an ariciact fold in the retina.] 
 
 The pecten presents a broad, and rather 
 long, pointed oval, with its blunt extremity 
 below. It is composed of 32 convolutions 
 whose free margins are united above in a keel, 
 and whose wide and thicker posterior fourth 
 covers nine equally long double coils. It 
 then slopes to the superior pointed extremity 
 of the disc, having joined, above, the remaining 
 nine unequally short coils. 
 
THE FIXDIS APPEARANCES IN \ /IIOIS ORDEHS OF BIRDS 
 
 80 
 
 Gannet. Siilti hoKsana. The picliirc of 
 the fundus, as shown in Pliilc XXIX, page 
 149, is llie result of ophthahnoseopie exami- 
 nations of three healthy, adult specimens. It 
 depicts the left ej'e; erect iniase. The general 
 tjlor of the eyeground is dull-yellow with 
 a gray tint, everywhere covered with light 
 gray dots, that are most numerous on the 
 up|H>r half of the fundus. Below and on 
 each side of the optic nerve are several 
 orange-red choroidal capillaries. These ves- 
 sels are fairly straight and run parallel with 
 the long axis of the disc. 
 
 The nerve-entrance and pecten are situ- 
 ated rather high up in the field; consefiuently 
 it is easy to examine the details of the jxri- 
 papillary background. 
 
 Above the upper end of ihe optic disc 
 and a little towards the nasal side, is a small 
 circular macular area, red in tone but sur- 
 rounded by a larger circle, like a gray shadow. 
 The margins of the latter gradually fade 
 into the background. 
 
 The visible margins of the papilla, apparent ly 
 composed of coarse, white, opaque fibres, 
 are not, as in many species, covered by the 
 pecten. The central part, near the root of the 
 pecten, is orange-red in color. 
 
 The pecten itself is evidently attached to 
 the disc for nearly its entire length, and 
 does not appear to come forward towards 
 the lens. 
 
 Redback Pelican. Pelecanun riijencens. 
 The individual (male) examined by the 
 writer was five years old and had been 
 domesticated in the Bronx Park for at least 
 three years. His refraction, estimate<l by 
 the skiascope, was about -M.D. The general 
 coloration of the ocular background is a well- 
 diffused, light reddish-brown; in some parts 
 of the field verging on gray. The pecten is 
 very large — larger at its free than at its 
 papillary extremity — and twelve distinct 
 corrugations in it are visible and can be 
 counted by the aid of the ophthalmoscope. 
 
 Although the canoe-shaped optic papilla 
 is almost entirely obscured by the mass of 
 the pecten yet it is uncovered towards its 
 temporal end, where it presents a very 
 white, pointed extremity; elsewhere it ap- 
 
 i-i'ars reddish-brown. Radiating filtres sur- 
 round the disc, like a halo. 
 
 AlHTHALlAN Pelkax. Pelecuiii.s aill- 
 ■tpicillatiin. The fimdus appi>aranevs of t!iis 
 bird, as demonstrated by the oi)hthalm()- 
 scofx', are portrayed in Plate XXX, page ' '••'. 
 
 The i)redominant color of the eyeyrouti 
 is a dull but deep gray, sprinkled g( nerally 
 with irregular dots, most numerous in the 
 upf)er part of th<> fundus. The lower fjuad- 
 rants of the field are covered with a dull, 
 orange-red choroidal capillary system, dis- 
 posed in a vertical direction. The dine is 
 a wide, pointed oval, exhibiting a numlxT of 
 l)right-red orange ridges that are uniformly 
 stippled with l)lack pigment dots. The 
 disc margins stand out as a dear white. 
 
 The pee ,t, broad and massive, seems to 
 fill the pupillary area. It projects far into 
 the vitreous, reaching, indeed, the posterior 
 surface of the lens. In spite of its large 
 size and intraocular disposition both the free 
 and the attached ends of the organ can be 
 outlined by the ophthalmoscope. Passing in 
 a radial direction from i^ circumference is 
 a number of opaque nerve fibres. 
 
 The single macular area is to be found on 
 the inner side of the fundus. It is surrounded 
 by a narrow, sharply defined, reflex ring of 
 greenish color. 
 
 Califohxia Browx Pelicax. Pelecanu.i 
 californicun. A young adult was examined 
 on the Coronado Islands, Mexico, by the 
 writer. The pupils measured about 5 mm. 
 and were not affected by light, as the bird 
 had just died. The fundus was well seen. 
 There was a distinctly whitish hcekground, 
 almost uniformly covered with niiimte gray- 
 black dots. The pecten was large, and of 
 the corkscrew tyix?, almost covering the 
 whitish-yellow optic disc whose margins were 
 easily made out. This bird seems, from the 
 position or his ej-es and their frontal disposi- 
 tion, to have binocular vision. 
 
 Serpentariiformes 
 Secretahy Bird. Gypogeranus (rel Ser- 
 pentarius) serpentarius. The ocular back- 
 ground of this species presents a most unusual 
 appearance. The colored drawing (Plate 
 
 
90 
 
 THE FUNDUS OCULI OF BIRDS 
 
 XXXI, page li51), ikpicts the right fundus 
 l).V the »Tocl iiimgo. The gi'iienil color of the 
 <!/i(jroiind is <hili gray, jjitted all civer \ith 
 mixed liglit and (hirk brown pigment grains or 
 dots, the darker iH-ing about double the s=ze of 
 the hgiiter granules. Interspersed with these 
 dots is u dense mass of minute, bright points 
 that cover the whole fundus, but they can be 
 observed only when tlie reltected light of the 
 mirror is focused upon them. These various 
 deposits give the l)aekgroun<l the apjx'arance 
 of a rough surface. There are no visible 
 choroidal bloodvessels, but a thin layer of 
 translucent nerve fibers surrounds the papilla 
 for a short distance, particularly along the 
 long axis of the nerve-head. 
 
 A little above the upper ond of the optic 
 disc and towards the nasal side is the forea 
 centralis, a round white dot enclosed by a 
 narrow ring of bright green. This area is 
 extremely sensitive to the reflected light of the 
 mirror. On the temporal side of the disc, 
 and above the end of it, is also a long, narrow, 
 sensitive area. This part is enclosed by a 
 shimmering reflex of green light. The animal, 
 otherwise quiet, becomes very fidgety when 
 this area of the fundus is examined, and gasps 
 for bn*ath as if it was being suffocated. 
 
 The opt)V disc is long and rather narrow, 
 both ends l)eing rounded off. It is quite white 
 and deeply pigaiented at its outer and upper 
 borders. 
 
 The pecten is of a lighter brown than usual, 
 is plainly serrLtea on either side and appears 
 as a narrow band that extends the whole length 
 of the disc. .Just before its junction with the 
 optic nerve-head it is stippled with bright, 
 orange-red grain The central part of the pec- 
 ten does not project far forward into the vitre- 
 ous; it appears to be quite narrow, while the 
 whole length of its upper edge or crest seems 
 rather wavy. On the whole, the fundus ap- 
 pearances present a picture unlike those oi any 
 other species examined by Head or the writer. 
 
 .\ccipitriformes 
 Lammergeier. Bearded Vulture. Gypae- 
 f;s barbatus. Plate XXXII, page 151, repre- 
 Sfcut:i an ophthalmoscopic view of the right 
 ocular fundus (erect image) of this bird. 
 
 The eyeground is slate gray, not stippled, as in 
 so many avian fundi, but presenting every- 
 where a granular appecrance. The lower 
 half of the fundus is cover- d with dull, orange- 
 red choroidal bloodvessi 1 s that run in a ver- 
 tical direction, parallel to the sides of the oi)tic 
 disc. 
 
 Above the papilla (about two disc breadths 
 from it on the na.sal side) is a snuill, round, 
 dark-brown pigmented pit, surrounded by 
 two distinctly marked, brilliant reflex rings, 
 each having a greenish tint. On the nasal 
 side of the nerve-head, but quite near the disc, 
 and much less distinctly outlined than the 
 depression just described, is the second macnlar 
 region with its fova. Looking at it through 
 the mirror it seems to have a soft, indistinct 
 but dark center. 
 All the fundal sectors are clearly seen. 
 The optic entrance is pure while, with an 
 orange-red central area from which arises the 
 pecten. This body is very narrow an<l lajK-rs 
 on its upper aspect for about one-fifth of its 
 length. It then becomes much broader and 
 almost covers the outer zone of the disk. As 
 it comes forward towards the lens its contour 
 resembles that of the Bald Eagle. 
 
 This fundus is singularly free from opaque 
 nerve fibres. 
 
 Bald EAGr.E. Ilcdiaetus leucocephalus. 
 The fundus picture seen in Plate XXXIH, 
 page 133, is the result of an examination of a 
 number of individuals. The writer, for ex- 
 ample, had an ophthalmoscopic view of the 
 eyeground of five Bald Eagles in the Bronx 
 Park collection. 
 
 The prevailing color of this bird's fundus is 
 dark reddish-brown, the lower half changing to 
 a dull orange-red. The whole eyeground 
 is covered with choroidal '•apillaries, and 
 dotted over with brown pigm..it grains, giving 
 it a rough, granular appearance. A gray 
 sheen pervades the upper part of the fundus. 
 On the temporal side and some distance 
 from the upper end of the optic nerve is a 
 brilliant, white, round dot surrounded by a 
 small, light-green reflex ring, which is itself 
 enclosed in a very br-lliant, narrow green 
 ring — the muscular region. On the nasal 
 side of the disc, and on a lo'al with this 
 
THE FT'XDI'S APPEARAXCES IN VARIOUS ORDERS OF BIRDS 
 
 01 
 
 tnnriila is another iircn, of a fpray color, siir- 
 roiiiidfil hy a fiin-shapcd, luminous reflex. 
 
 The optic ncrre-fniranre is distinctly white, 
 niid along its center is strewn a large luimher 
 of minute pigment dots. The outer margin 
 of the liisc is bordered with l)Ia<'k pigment, 
 as if a shadow were cast upon it liy llie [K'eten. 
 In this regard and in sonic olliers this fundus 
 resemhles the eyeground of the Sea Eagle. 
 
 WiiiTE-BKLMKD Se.\ EAfiLi;. Ilaliaetus 
 lencoijaskr. The ocular fundi of three in- 
 dividuals of thi . siK'cies were found to he iden- 
 tical and furnis.i the oi)hthalmoscopic appear- 
 ances shown in Plate XXXIV, page 1.5,'5. 
 
 The rolnralion of the eyeground is mostly 
 dull-l)rown, the lower quarlrants of the field 
 being covered with dull, orange-red capil- 
 laries evidently choroidal. 
 
 The optic di.ic is a long white oval, whose 
 center is tinted with oran)^> and covered with 
 tiny pigment dots. The papillary margins 
 arc white bordered with black pigment. 
 
 The upiK-r half of the fundus is covered 
 by a mass of dull gray dots. There is a well 
 defined reflex near both maculae, each similar 
 in position to that seen in the Kestrel. These 
 areas are evidently very sensitive to light, as 
 the bird becomes very fidgety and irritable 
 when the reflected rays from the mirror are 
 thrown directly o!i one or other fovea. 
 
 The pccL'ii is very large and comes well 
 forward towards the posterior surface of the 
 lens. Both extremities of the organ are 
 clearly visible through the ophthalmoscope. 
 There are very opaque nerve fibers to be seen 
 in any part of the eyeground. 
 
 American Osprey, or Fish Hawk. Pan- 
 dion halia'.ivn carolinensis. When light is 
 thrown directly from the front and at a dis- 
 tance of one foot, on the pupils of this bird of 
 remarkable visual powers the red reflex is 
 scon to occupy fully three-fourths of each 
 pupillary area. 
 
 By the aid of the ophthalmoscope the 
 writer found the general funded coloration to be 
 bluish-gray with a suggestion of brown. 
 These tints are uniformly distributed through- 
 out the ocular background, and there is very 
 little of the striation seen in Duteo and other 
 genera. 
 
 The pecten almost entirely obscures the 
 view through the pupil of the optic disc; it 
 is a compact, intensely black body, showitig 
 about ten convolutions. 
 
 Mainly because of the undilated pupil and 
 large .>ecten no definite fovea was visible. 
 
 EinopKAN Kestiiel. Tiiiiiiiiiciihis ahiu- 
 darina. Plate XXXV, page 15.5, is a faithful 
 reproduction of the ophthalmoscopic appi.'ir- 
 anees in this sharp-sighted species, depicting 
 the right eye by the direct method. 
 
 The ground-color of the fundus is a light 
 brown, or brownish-gray. The l;)wer quad- 
 rants are streaked with orange-red, choroiilal 
 capillaries that run in a more or less vertical 
 direction, an«l become more distinct ami 
 brighter ri'd as they approach the pt'iphe.-y 
 of the field. The optic disc is a long, white 
 oval, showing its margins well beyond the 
 pigmented and fringed pecten. The central 
 area of the papilla appears to be hollowed out 
 like a canoe and the pecten does not overlap 
 it at any point of its cireumference, as is so 
 frequently the case in avian fundi. 
 
 The disc extends as far downwards towards 
 the fundal periphery as the observer's eye can 
 reach. At its lower extremity several small 
 ehoroid.il vessels can be seen. 
 
 The pecten has a rounded but pyramidal 
 form, sloping towards the centre of the disc 
 at both ends. It is of a dull-brown color, and 
 corrugated like a photographic camera. At 
 the junction of pecten and papilla are scat- 
 tered numerous brown dots, so disposed as 
 to give the former the appearance of a web. 
 The upper part of the eyeground is quite 
 devoid of choroidal blood-vessels, but is 
 covered with minute white dots. The fundus 
 is much clearer of the retinal shimmer or re- 
 flex noticed in most birds. 
 
 The two macular regions are very distinctly 
 visible. The nasal macula is situated just 
 above the upper end of the disc and about 
 half a disc-length on the inner or beak side 
 of the eyeground. It is a dark-brown spot 
 with a pale area all around it. Outside of this 
 region and enclosing it are two distinct, pale- 
 green, filiform, reflex rings, the interior rings 
 being quite free irom the white dots. On 
 the outer aspect of the eyeground, about 
 
09 
 
 THE FUNDrs OCILI OF BIRDS 
 
 «mo-tliir<I f hi- lenRth of flu- disc nl)ovo nn<l two- 
 thirds to ilfi outer siilo, is st-on thi- sf-cond or 
 t(-nipornl nin(-uhir n-Kion. At its ((-nlcr is u 
 li«lil. limy spot surrounded l)y a dark hrowii 
 area. Both these area- are in their turn 
 enrirelod hy a small, pnle-green, reflex rins 
 about one-fourth the diameter of the corrt-- 
 spoiiding circit- about the superior macula. 
 Sl(-nder, opaque nerve fibers run out at ri^ht 
 angles to the disc on both sides. 
 
 Hkd-tailkd Hawk. HuIco borcalia. The 
 
 f)/)/iV-«<T(r r/f/rrtwrc in the indiviiluals examined 
 by the writer is almost entirel,<- covered by the 
 prrleii, except at its superior end. which can be 
 outline(l and examined by tin mirror. It lies 
 (obli(iuely) at an angle of about 70 degrees with 
 the upper mandible, and can be seen through 
 the more or less translucent pecten. The back- 
 ^.ound generally has a striated npp«-arance 
 with the choroidal ves.sels showing through. 
 
 Little Bistahd. Te ix Mrax. Plate 
 XXXNI, page 155, reprodues the left fundus 
 oculi, direct image, of this species. The 
 fundal coloration is mostly a warm gray, 
 covered with small, dull orange-red dots. In 
 the lower half of the field and on each side 
 of the optic nerve entrance is a number of 
 choroidal blood-vessels of a dull oran^je-red 
 color, running parallel with the disc. 
 
 So far as seen, the papilla is a dead white; 
 optic fibres form a fringe-like setting about it. 
 The central zone of the disc is covered by a 
 mass of minute, brown, pigment deposits of 
 irregular shape. Opaque nerve fibres extend 
 at right angles to the disc on either side. 
 
 A little to the temporal side, about one 
 disc-lengtb from the upper end of the optic 
 nerve, is a small, brown spot like a tiny hole. 
 This macular area is surrounded by a brilliant, 
 green reflex ring. 
 
 The pecten, of a dark chocolate-brown color 
 ;ind shaped like a corkscrew, comes well for- 
 ward towards the inferior border of the lens. 
 The fundus of the Great Bustard ~ 0/("« 
 tarda — closely resembles that of 0. tetrai. 
 
 Strigifonu ., 
 T \NT Owl. Syrnium alticn. (Figs. 132 
 and 96). The ocular background of this 
 species shows, macroscopically, a solitary. 
 
 tempiiral, macular region and fnrea. This 
 single macidar area is about a disc length and 
 a half abov«- and to the temporal side of the 
 smaller or sup«-rior end of tlu- pt-cten. 
 
 The irrt-gtdar shnp«- of the (-yeball and fun- 
 dus in the Owl must not, in this connection, 
 be forgotten. The comparatively undersized 
 prclen exhibits 14 convolutions (four large 
 and of equal size, ten unequally snudlerj that 
 when viewt-d from abov(- look like a small 
 bunch of raisins. Between the folds may 
 Ik- seen the margin.s of the optic nerre en- 
 trance. The crest surmounting the upper free 
 border is very thin, inconspicuous and unde- 
 veloiK-d. 
 
 The nphlhalmoncopic ricir of the normal 
 fundus (the result of examination of numer- 
 ous individuals) is shown in Plate XXXVII, 
 page 157. 
 
 On the outer asp<-ct of the papilla and 
 about one disc length from it, on a kvel with 
 the uppi-r margin of pt-cten, is a slight de- 
 pression (macula) alnunt devoid of cho- 
 roidal vessels. Its centre is a dark red color, 
 the whole macular region closely resembling 
 the same area in the (brunette) human eye. 
 On the margins of this depression and sur- 
 rounding it is a bright circular reflex. Head 
 found this reflex to be so bright and dense in 
 some individuals that it was difficult to see 
 the other macular details, although, in most 
 instances, by shifting slightly the reflected 
 rays from the mirror the macular margins 
 come out distinct and sharp. For some dis- 
 tance outside this foveal ring the eyeground 
 is seen as if on<- were viewing it through a 
 translucent, grayish mist or haze; and the 
 fundus thus seen generally appears to be 
 granular with a few, small choroidal capillaries 
 showing here and there. Inside the ring, 
 however, the details are .strikingly clear, and 
 the coloration bright red. Above the macula, 
 in the outer side of the disc, is a quantity of 
 dark pigment deposited between the cho- 
 roidal vessels, l.y contrast making the latter 
 stand out as of a bright orange color. The 
 inner aspect of the fundus appears yellow; it 
 exhibits numerous choroidal blood-vessels, 
 whose yellow tint is distinctly brighter near 
 the inferior segment of the disc. 
 
THE FTXDIS APPEARANCES IN VARIOlS ORDERS OF BIRDS OH 
 
 1 
 
 Fig. 13i. Tawny Owl {Syrnium alum) x'l. 
 
 Fig. 133. Greater Siilphur-crested Cock.''»oo (Cacatiia galerila) X9. 
 Macroscopic Appearances of the Fundus Oculi in the Preserved Eyes of Birds. 
 
 i 
 
§4 
 
 THE FlNOrs (K-rU OF BlltfJS 
 
 ntmioxviNO Owi.. Sftrnli/to nil 
 hjipogtrn. The twiiljir fiiinlii.i nt this .>.|h« 
 irr«'«iilnrly roiiml, iis in nil lli<- Owl*, iixl 
 ill pnpiirrd s|M(iiiitns I In- .UlaiU sli.iw <|is- 
 linrlly. 
 
 Tlic single, tcinpornl, oviil miirnlnr rrgioi. 
 lies iiliovi- nnil nhoiit a ilisc IciiKtli anil a half 
 from Ihi- up|XT <ii<l of lln- papiHa. In Ihf 
 rt'nfer of thi- niariila is flio fovea — a ilark 
 pitfiiifiKcil spot «ifli fiiif granule!* arran^'.'il 
 rap-like aliovc it. Outside this, iiftain. •■, the 
 ovoid circuinferinee of this region, 'iirom- 
 pletely edsed with fine dots. These art more 
 ni'.iieroiisly distriltiited Ik'Iow the macula 
 than above it. C >nne<t d with tin maeiilar 
 i-eRion is a ji^ht colored and rather liroad hniid 
 that extends horiitontii y to the center of the 
 visil.lv- ImckKroiind. It is unevenly divided 
 into two strips liy a parallel arrangement of 
 minute pitrnient dots. 
 
 Seen from ahov- the relatively small /xv/ch 
 closely resemhli s a disarticulated, acumiimte 
 leaf, the stem repre-'-ntiiiK tin spinous pro- 
 jection immediately ai,ove tin- lowest terminal 
 convolution. The light doutile folds of the 
 marsiipium .sIoim- backwards and cover most 
 of the optic entrance; they meet above in a 
 uniform, very narrow, .slightly undnlatinj? 
 crest who.se posterior end i)rojecls half the 
 li'-ight oi' .he unlyinj? coil well into the vitre- 
 ous cavity. An extension upwards of thi 
 Ions axis of the disc cuts the retinal band at 
 till' junction of the inner and second fourth, 
 making an infiilapapillary angle of, perhaps, 
 40°. 
 
 This interesting Owl is cspt>cially subject, 
 like other .Strigifornies, to pathological varia- 
 lion.s in the fundus picture due to confinement 
 and domestication. Both Head and the 
 writer examined a nuni'cr of individuals that 
 undoubtedly exhibited choroidal di.se-se and 
 other pathological changes. Rejecting these, 
 the p'lieral color of the fundus of this species is 
 found to be dull-orange, mottled and blotched 
 in its upper half with orange-red. Choroidal 
 vessels are plainly seen, covering all the lower 
 part of the eyeground, just as in the Tawny 
 Owls. The well defined macular area is .seen 
 within tl e outer half of the f;i.idu.s, a little 
 above the upper extremity of the optic disc. 
 
 It is distinguished from the surrnundinK cho- 
 roid by a collection of minute pigment 
 grannies or dot.s with n brigh?, while .spot in 
 their centre. 
 
 The opilr di.w is white and of oblong shapj , 
 slightly rounded at the ends. From its ••dgcjt 
 run a few. short nerve fih.es that form a com- 
 plete fringe about the visible papilla. 
 
 Tin- ptrtrn is decidedly larger in proportion 
 to l)odily measurements than one finds it in 
 most of the larger Owls, espe<ially larger than 
 in the Tawny Owl. It exli-iids well forward 
 into the vitreous, and its lower half ai)p<'Hrs 
 very massive and of a dark brown color. The 
 jM-ctinate coii.oliitions are ph'.inly seen and 
 the anterior or iippt-r half is more delicate in 
 si met lire, being jMrforatid where it joins the 
 disc. Here it forms a dark network on the 
 
 siirfat f the nerve-head whe— , also, a few 
 
 red granules mingle with the cho<'olatc-bruwn 
 texture of the |H'cten. 
 
 Snowy Owi,. Sijvlea ri'-tra. It is a popu- 
 lar belief, and one held in many public 
 aviaries, that ihese owls are likely to become 
 blind if much exposed to daylight, ("on.se 
 (|uently they are often caged in darkness or 
 semi-darkness, although their habits are really 
 diurnal, or at least th'- an as much Day 
 birds as Night birds. 
 
 In any event the ch inges in habitat in- 
 volved in their captive surroundings arcs in 
 Hie judgment of the writer, responsible for 
 iTi'ain alterations found in their fundi and 
 in those of other Hubonidae kept for more 
 than a >"ar or two in pubi'c gardens. 
 
 The II (rnial, dominant coloration .,j thi 
 fundus is very light yellow-red, but de- 
 cidedly less reil than in Symium aluro. See 
 Plate XXXVH, page 157, of this Atlas. In 
 the first individual (two years in captivity) 
 examined there were throughout iheleft lack- 
 ground extensive choroidal changes, e.spec'-lly 
 one cruciform, pigmented, partially aln,. no 
 area running across the field towards the 
 nasal side. These long, st.-iated alterations 
 were also seen in the temporal part of the 
 fundus. 
 
 The large, club-shaped pccten springs from 
 a well defined whitish, ovoid di.«c. The mar- 
 gin of the papilla is occupied by nu.Tierous 
 
TIIK FINms .\I'I'KARAN( FS IN \ AHHHS ()Hr)FHS OF BIIIDS 
 
 IM 
 
 ftiiiiill.dotli'il ;ii«nnnt<<l,l.'i).>»it«. Tli«<Miiliir 
 iiii'iliu Wire iilirclv < Icnr. 
 
 In the riijhl fitiiiliii tin- |)iitli<ilii);ii'.'i| cliiiiijfcs 
 wiTi (lif Mime cxcciil tliiil linviiri'N llii niisiil 
 siilr uf the piipillii then- .- a liiri{c, jitri)|iliic, 
 liiKiiK'iilfil uri'ji cxtfriiliii;,' ;ilriiost o tin- 
 (MTiplicry of tlic f;iri<lu^, «iitirt|y iililik" the 
 sriijilliT iirid iiarritivcr loioii in tlif left cyi'. 
 Alt'i>;cllicr the inorl>ii| cliiiiiKrs in the ri>;ht 
 <•>•(• lire inori- niiiiHTiiiis tluiii in tli<- left. 
 
 li a yoiiiiffcr iniliviiliiiil tlic (oinratioii of 
 I Ik- hack^ro iii.l, the i»apilla. tho |Hclfn nnd 
 thf iiiaciilar r<"j;ion were precisely as in tie 
 firsl-nienijoned hird. The pathological N-- 
 sions, however, were entirely (litFerent. They 
 appeared in each eye as four or five rather 
 sniall. round, pijfnienled exudates, having a 
 whitish atrophic- (?) centre, much iiKc tho 
 
 I linni-sized deposits in the human «'yi" 
 
 when alfected hy a <lisseminatcd choroi<litis. 
 Fi ioi'K.w Haiin Owl. SIrix flnmmca. 
 (Figs. 97 and IN; macroscopic view). This 
 fundi!- shows the .single s«'iisitive regioti.s 
 iiiiiinilii anilfomi) on the temimral aspect of 
 the field, slightly above and les.s than the long 
 ilisc-diamcter from the upfwr t« nination of 
 till' optic entrance. The fovea is represented 
 hy a large dot in the center of a number of 
 minute granules, surrounded by an u. 'tinted 
 ari'a incloseit in a ring of still more numerous 
 pigment grains. 
 
 The snudi pcrlcn is made up of U sHo-*, 
 stout convolutions (the largest ten of equal 
 size) thai only partially cover the nerve head, 
 which has pignie t granules scattered over 
 its surface. The pectinate coils meet above 
 and are j lined by a straight, thin, cord-like 
 crest. Th / all incline towards the posterior 
 free border. The upper free margin is about 
 half the length of IIk papilla. 
 
 The fundus oeuli of the British species, 
 painted from a recently captured specimen, 
 is depicted on Plate XXXVIII, page 157. 
 With Mr. Head, the writer examined many 
 of the Stri^idn; confined at the time (July, 
 lf)12), in the gardens of the (British) Zoolog- 
 ical hoeiely. Those that had bee- caged two 
 yi.irs or more were plainly affecttil with 
 choroidal changes, mostly of the disseminated 
 choroiditic typ<>, the choroidal atrophy and 
 
 pijriiient de|)osits v.irying in iniount but 
 nciirly always niori- marked thi" longer the 
 birds had lieeti imprisoned. 
 
 The gemrul luiiv iif lit, ii/i finiitnil in .S7n>- 
 flitmmea i.o dull -ray with bright, clearly out- 
 lined, orange i(d choroidal vessels distributed 
 all over the fundus, except at the macular 
 rej;ion. At this area the lint is much gr.iyer, 
 Ining, in addition, stifipled with snuill, irregu- 
 lar blotches of oran^'e-r«'d and gray ilots. 
 
 The macula is also sulfused with a gray 
 rellcx. It is situated above the i' ■>«t end of 
 the optic disj- and nearly in a hue with th' 
 long axis of that rirgan. 
 
 The papil'a is long and narrow, wil li pointed 
 •■nds, and is apparently made up d coarse, 
 white fibre-bundles the central portion of 
 which is coven'd with minute, iirown, pig- 
 ment grains, that have a distinctly reticulated 
 apiK-aranci'. These white fibres bonhr the 
 nerve-head all around. 
 
 The dark-brown, convoluted pectcn of the 
 Barn Owl is nuich larger than that of the 
 Tawny Owl. It is also placed farther for- 
 ward towards the lens than the pectcn of the 
 latter bird. Fxtending from both sides of 
 the di.sc are a few, dull-gray fibres that stretch 
 a short di-tance acro.ss the fundus and then 
 di.sapjM'rir. 
 
 Two iK'cimeus of Slrir pratinmla and two 
 of Strij- perf^a revealed ophthalmoscopic 
 appearuiKO <|i«ite - nilar to those .seen in 
 Strix flan, ,i. , sc | |,at the fundi of the 
 two first lanied -es ai. generally of a 
 
 deeper grii,\ All ..ese (four) individuals 
 wen- suffering f-nm * !«oroidal changes. 
 
 P' fo'~mes 
 
 GuE.\T Su.-t .) Cock -TOO. 
 
 Cacaliin gilerifa. ;ind .33; mac- 
 
 roscopic view-, i i^ •< M, iilar backgrouiu/ 
 there is no visible /«» ir macular area. 
 
 The niedium-size<i '-ieii exhibits rather 
 broad, rotiniled coin I s -oiiie 24 iii alf, 
 
 that arc joined abov hea\ process or 
 
 crest of irregular outlm. »» latl« < extend*' 
 
 one-half the length i.i xh- upper irflcr 
 
 joining together nine e<|UHi .t& 4">»bl.- fold* 
 From this keel-like body tht m^ *h' p<->- 
 
 ten slopes ofl to the froUi, e« -rtir. 
 
IMI 
 
 THE Fr\nUS OCl'LI OF BIRDS 
 
 n( llic wliili»li iii'tvr lii-ail, which \* tloltfil 
 with Very >tniill |iit(nii-nl unttiiilo. 
 
 Thi- i)i>hthiilini>/iriti>ir ri/>/«(ir(iMrc,« of th'' li'ft 
 <\vi' of Ciiraliitt giilrrila, vwrt itiiiip', iin" |Mir- 
 lr.i.V.<l in ri,.t.- XM, imgc l«l. The Ixirk- 
 ijriiiiiKl i^ of ii fairly uiiiforiii, 11^1)1 Krayixh-lihii- 
 color, sprinkled with iiiitiiitc white dots that 
 arc iiilcr«|)«'r'«<il with niiiiiy whh iiiiiiicroiM 
 liiit soiia-wlial larKcr dark ^ray dc|>o»it!i. 
 The macular ana, at the ii|>|M'r-iniicr <|uad- 
 rnnt, i* nii irrcnularly round, liiifht brownish 
 area whose diameter i<t half tlie disc lenjfth. 
 It is not, as in many Birds, surronnded and 
 defined hy an outer rinjj; the jM-ripliery fades 
 into the : iirrountlmK ^ray of the fundus. The 
 up|M-r sixth of the long, pointed papiUa is 
 ilislinclly visilile where il is not covered liy 
 the indented perlcn, whose twelve doutile folds 
 have a corkscrew termination altovc. I'or- 
 tions of the disc liorders can !><• M'cn from 
 aliii\e through the plications, except at its 
 posterior terminal where the dark-hrown nuiss 
 entirely covers it. Knint, wiiitish lines of 
 opacpie nerve fibres extend from the nuirKin.s 
 of the upper half of the disc n short distance 
 across the ct-ntre of the eyeground. 
 
 OiUNOE-wiNCED Parrot. Chnjunlin ama- 
 zona. I'late XXXFX, page 159, n'presents 
 the ophthalmoscopic appearances in the right 
 eye of this species. The dominant color of 
 the iijeground is deep gray tinted with buff. 
 The lower sectors ar ;ho p«-rii)heral zone 
 of the fundu' are >i if used with pink, the 
 background generally l)eing punctuated with 
 minute, duM-yellow dots. 
 
 The macular area is situated towards the 
 nasal side of the disc, a little above the 
 end of the pectcn. It is slightly depres.sed 
 an.l enclosed by u rather bright but pale-green 
 reilex-ring. Extending from the circum- 
 ference of this circle, slightly above as well as 
 below, are a few translucent fibres, pale 
 gnn-n in tone; and at its centre is a dark- 
 gray dot or depression, with a small, faint 
 halo extending from its upper edge. 
 
 The optic nerre-head looks as if it were 
 composed of coarse, white, opatiue fibres, 
 which form a fringe all around the deeply- 
 colored jx'cten. The papilla is long and 
 boat-shaped, and its outlines can be traced 
 
 the whoh- length of the pecten. Many f5n«», 
 gray, opaque nerve fibres extend from the 
 ■iiurgins of the papilla, cross the bickground 
 I f the eye and un; eventually lost in the 
 fundal tissues. 
 
 The dark-brown perien, MfU from -"Imve, 
 has a spiral form, with n tag or tail-piec<< at 
 the upixr end. A lateral view shows it to 
 Ih- plicated, like a fan. It stands well forward 
 towards the lens. 
 
 The light reflected info the eye from the 
 ophlhalnioscopic mirror does not a(>pt>ar to 
 disturb s|M'cimens of the s|H-cies .it all, 
 uidess it is concentrated on the macular 
 region. 
 
 White-fronted Ci'ban Coniire. (?) 
 Conurun ridgu-ny. The writer examined with 
 tlie ophthalmoscope the fundi of an individur 
 four years old that had Ixtm an inmate of 
 Bronx Park for three months. Neither a 
 one-fifth of one |H'r ot'nt soLition of sulphate 
 of atropia nor a homatrophine and cocaine 
 mixture had any effect on the size or motility 
 of the pupil. 
 
 The eyeground was generally reddinh- 
 gray; the pecten was large, convoluted and 
 extended well into the vitreous cavity and 
 approached the posterior lens surface. There 
 was no , ell-defined macular regie I. The op- 
 tic entrance was almost covered, and a viev,- 
 of it obscureti, by the base of the pecten. 
 
 Kakapo. Owl-Parrot. (New Zealand.) 
 Stringopn habroptilus. In July, 1014, the 
 writer examined the .single specimen then in 
 the gardens of the Zoological Society at 
 Regent's Park, London. The bird had, at 
 that date, l)een in captivity two years, and 
 seemed dazed when exposed either to bright 
 natural or artificial light. The keeper reported 
 that the bird is very quiet during the daytime 
 but digs in the sand of bis box at night. The 
 lids have no cilia-like protection — only scat- 
 tered plumules on the otherwise naked lids. 
 He has large pupils and a dark brown iris. 
 
 The red-brown fundus is fairly easily seen 
 with the ophthalmoscope without using any 
 mydriatic. The frontal position of the eyes 
 (found in all Strigiformea and to which 
 order the writer believes this species right- 
 fully belongs) is marked in this animal, and 
 
TIIK KINDIS .VIM'K.VHA.\( KS rs V.MiUMS OUDKUS OF BIHDS 
 
 07 
 
 I 
 
 Fip. 135. Anna Hummingbird {Calypte anna) ;<31. 
 Macroscopic Appearances of the Fundus Oculi in the Preserved Eyes of Birds. 
 
 J 
 
08 
 
 THE FUNDUS OCULI OF BIRDS 
 
 the bird evidently possesses binocular vision 
 as he always looks straight ahead at objects 
 that he wishes to see distinctly. Plate XL, 
 page 159, furnishes an ophthalmoscopic view 
 of the right eye, erect image. The eye- 
 ground is orange-red stippled all over with 
 lighter orange dots. The lower half of the 
 fundus has a large number of minute, dark, 
 reddish-graj' depots of pigment intermingled 
 with lighter dots; also, a great many cho- 
 roidal blood vessels run in a vertical direction 
 over the field of view on either side of the 
 optic entrance. They become more numerous 
 towards its lower periphery. 
 
 The macula is placed, as in Owls generally, 
 on the temporal side of the optic papilla, 
 about one disc-length from its upper end 
 and half that distance to the temporal or 
 outer aspect of the fundus. It is a bright, 
 orange-red area surrounded by dark, red- 
 gray pigment, like a shadow. There is no 
 circular sheen around it, such as has been 
 noted about other avian foveee. 
 
 The optic nerve-head is white, and along 
 its center appears a network of minute, 
 brown pigment dots clustering around the 
 sides of the jjecten. A few white opaque 
 nerve fibres extend a short distance on either 
 side and about the upper end of the disc. 
 
 The pecten, of the u:ual black-brown color, 
 extends the whole length of the disc. It is 
 rather straight in its upper half but is more 
 convoluted towards the lower part, where it 
 is quite massive and resembles a corkscrew. 
 This portion of the pecten comes markedly 
 forward towards the lens so that it more 
 nearly resembles the same organ in the 
 Burrowing Owl than in the Parrot ; as indeed 
 the foregoing studies of the fundus oculi 
 lead unmistakably to the conclusion that 
 this bird belongs to the Owls rather than 
 to the Parrots. 
 
 Coraciiformes 
 
 European Kingfisher. Alcedo ispida. 
 (Figs. 99 and 113; macroscopic view.) This 
 remarkable background .shows two exten- 
 sive, well-defined, circular macular regions, 
 both supplied with a large, deeply pigmented 
 fovea. The nasal macula is large and 
 
 saucer-like. The Jmea nasalis is surrounded 
 by a nebula formed of microscopic dots 
 thai are, however, absent at the lower 
 nasal third of its margin. About the same 
 distance down and temple wards from the 
 superior end of the disc, as the deeper fovea 
 is up and nasalwards, lies the secondarj' area 
 temporalis. [In the sketch the wall of the 
 globe is cut away to expose it.] This tem- 
 poral macular region is smaller and not so 
 well defined as the nasal fovea but it exhibits 
 a distinct pigmented centre surrounded by a 
 dotted ring. 
 
 The large and curious pecten exhibits 17 
 double folds, two at the superior terminal 
 of the organ. These 34 convolutions are 
 very thin (like strips of paper), and through 
 the wide intervening spaces almost the 
 whole surface of the optic disc can be seen 
 and its outlines readily traced. The papil- 
 lary surface is dotted exactly like the sur- 
 rounding retina. The crest or free border 
 of the pecten is quite narrow, and caps the 
 pectinate mass in a wavy line. The naked- 
 eye view from above gives a picture much 
 like a fern frond. 
 
 Laughing Kingfisher. Dacelogigas. The 
 ophthalmoscopic appearances of this species 
 are pictured in Plate XLII, page 161. 
 
 The fundus oculi is in general of a light 
 fawn-gray color mingled with irregularly 
 shaped, white or gray-white dots, except in 
 the neighborhood of the optic nerve where 
 it is orange-red, like the glow cast on the 
 sky by the setting sun. 
 
 The optic nerve entrance is long and narrow; 
 it is white except along it - central area, which 
 is orange-red striped with brown pigment 
 dots. A large number of opaque nerve 
 fibres run out on each side of the optic nerve 
 and at right angles to it. 
 
 The pecten is very long and narrow and 
 has the appearance of a brown centipede. 
 
 The macula is very conspicuous. About 
 half a disc-length from the upper end of the 
 nerve, towards the nasal side, is a small, 
 round, dark-brown hole, surrounded by a 
 very narrow, bright green ring. This circle 
 encloses a smaller area that is of a darker 
 gray and devoid of the dots seen at other 
 
THE FUNDUS APPEARANCES IN VARIOUS ORDERS OF BIRDS 
 
 !)!) 
 
 Fig. 137. Red-.sbafted Flicker {Colaptes mexieanus) X li. 
 Macroscopic Appearances of the Fundus Oculi in the Preserved Eyes of Birds. 
 
 is:..si 
 
100 
 
 THE FUNDUS OCULI OP BIRDS 
 
 parts of the eyeground. The forca na/ialis 
 always appears directly opposite the pupil; 
 there is no fovea iemporalis visible to the 
 ophthalmoscope. 
 
 Common Hoopoe. Upupa epnp.i. (Figs. 
 134 and 100; macroscopic view.) This niedi- 
 iiin-tinted fundus exhibits a .single macular 
 region, — a round figure whose diameter is 
 equal to the extreme width of the papilla. 
 It is depicted by a dotted line of pigment 
 grains that are more numerous below. The 
 forea is shallow and not well-defined. 
 
 The relatively large pecten has numerous 
 (about 40) convolutions; it forms a compact 
 mass that almost obscures the papilla, par- 
 ticularly when the disc is viewed from 
 above. It is covered by an ovoid cap that 
 extends from the ridge-like (upper) free 
 border about one-fourth of the distance to 
 the pectinate base, whose full length is more 
 than four times its extreme width. 
 
 Bl.\ck Hounbill. (?) Spagolobuti adratus 
 An ophthalmoscopic view of the ocular 
 fundus of this species is pictured as Plate 
 XLIII, page 163 of this work. The painting 
 is of the right eye by the direct method. 
 The shimmering reflections from the trans- 
 lucent retinal elements of the fundus make 
 an accurate ophthalmoscopic view some- 
 what difl^cult. The principal color of the 
 eyeground is dull gray, interspersed for some 
 distance about the optic nerve-entrance 
 with a mass of fine, opaque fibres that extend 
 about a disc-length over the fundus. Beyond 
 the fibres are several dull-colored, choroidal 
 capillaries that cross the fundal field in a 
 vertical direction. Near the macular region 
 the fundus is illuminated by a brilhant 
 gray iridescence. 
 
 The optic disc is a long, white oval, that 
 extends downward and a little inward towards 
 the inner or beak side of the head. 
 
 The pecten is very large, the lower seg- 
 ment being carried so far forward behind 
 the iris that it is difficult to inspect it with 
 the ophthalmoscope. Instead of the usual 
 fringe of pigment the pecten presents serrated 
 margins. 
 
 The macular region is quite circular and 
 is red-brown in color. An inner circle is 
 
 dead white, while the foveola is represented 
 by a dark-red, central spot. There are two 
 bright rings around the macula of an irides- 
 cent, blue-green color, the fundus between 
 the two circlets being a light, luminous gray. 
 
 EriiOPE.t.v NujiiTJAR. CaprimiHijas euro- 
 peus. The fundus picture (left eye, erect image) 
 of this bird is furnished by Plate XLIV, 
 page 163. 
 
 The eyeground appears orange-red, every- 
 where stijjpled with small, red and brown 
 patches of irregular shape. Scattered about 
 are several pigmented areas, such as one 
 sees in the eyes of human .subjects with 
 disseminated choroiditis. This condition, 
 somewhat modified, is seen in many owls 
 long confined in zoological gardens or aviaries, 
 and it seems to be confined to Night Birds, 
 and to be one of the results of confinement 
 and domestication. In many respects, also, 
 the eye of the Nightjar resembles that of the 
 Strigifornus except that Caprimulgus has 
 fewer choroidal vessels in the lower half of the 
 fundus. These arc faintly outlined, but they 
 give to that part of the eyeground a deeiwr 
 red than the remainder of the background. 
 
 The optic papilla is short and broad. 
 The antero-posterior view with the mirror 
 shows it as a dull, grayish-white body large- 
 ly covered with brown pigment dots. Its 
 margins, where it is not obscured by the mass 
 of the pecten, is much lighter in color. Radi- 
 ating from the sides of the disc, and extend- 
 ing for a short distance on either side, are 
 a few white opaque nerve fibres, which are 
 light gray and become less distinct on the 
 outer side of the papilla. 
 
 Anna Hummingbird. Calyptc annw. 
 (Figs. 101 and 135; macroscopic view.) The 
 ocular background of this sjjeeies shows two 
 plainly marked macular regions, the nasal 
 fovea being, as usual, the better defined. 
 This area nasalis is seen as a black spot 
 entirely surrounded (except at the lower 
 fourth of its circumference) by a halo of 
 dark pigment grains. Outside of this is an 
 untinted zone that, in its turn, is encircled 
 by a nebulous ring broader below than 
 above. The tunics of the eyeball are cut to 
 show the temporal site of the second macular 
 
THE FUNDUS APPEARANCES IN VARIOUS ORDERS OP BIRDS 101 
 
 ri'Kion. Fi(,'iire 135 furnishes an ciilarncd 
 piclure of this area, whicli is a (liipliratc of 
 the area ua.iali.t except that the fovea is 
 sliallower anil not so bhick, wliile the pij^nien- 
 tation of the surrounding ring is less marked. 
 The pedeii has Hi convohitions — IC on 
 each side — united to a long, narrow sinuous 
 crest. The fold that constitutes the front of 
 the free border becomes broader and rounded 
 as it gradually slopes from the crest to the 
 superior end of the optic disc. Uncertain 
 glimpses are gained of the papilLiry borders 
 through a few spaces between the more cen- 
 tral pect'.nale folds; otherwise the surface of 
 the optic entrance is entirely obscured. 
 
 Cuculiformes 
 
 Yellow-billed Cickoo. Cocn/ziis ameri- 
 catius. (Figs. lOi and 130; nuicroscopic view.) 
 
 The single macular region is of immense 
 size — considerably larger than the untinted 
 area on the nasal side of the pectin, and 
 two-thirds as wide as the optic entrance is 
 long. A nebulous zone of pigment <lots 
 encloses this large .sensitive area, the dots 
 being drawn as distributed everywhere ex- 
 cept at the upper fourth of the zone, where 
 they are comparatively few. Tin- foira oc- 
 cupies the exact center of the circle and 
 shows as a dark pigiuent spot with its upper 
 two-thirds covered with black granules 
 closely spread above it fan-wise. 
 
 The peclen has about 24 heavy, compact 
 convolutions that almost completely cover 
 the optic entrance. They are joined at the 
 irregidar free border above by a translucent, 
 cigar-shaped band of tissue that extends 
 the whole length of the crest. 
 
 The anterior and pointed terminal of the 
 papilla approaches to within less than a 
 disc width of the temporal boundary of the 
 macular region. 
 
 Ei'HOPEAN Cuckoo. Cucuhis canorus. 
 The ocular fundus of this bird, as .seen in 
 living specimens by the aid of the ophthal- 
 nioscoj)e, is depicted on Plate XLV, page 
 105. The picture is drawn of the left eye; 
 erect image. 
 
 The coloration of the cycgronnd is gr.ay 
 with a suggestion of fawn, everywhere show- 
 
 ing minute, grayish-white dots. Towards 
 the lower quadrants of the fundus and in 
 particular at the extremity of the pecten the 
 background is suffused with a duii pink. 
 Near the optic nerve on either side are 
 several, plainly visible, orange-red choroidal 
 vessels. 
 
 The macula is seen above the disc, towards 
 the nasal side. This area, slightly red in 
 tone, appears depressed below the fundal 
 plane, although no definite fovea is visible 
 with the mirror. 
 
 The papilla is almost completely covered 
 by the pecten, so that only the outlines of 
 the former can be seen by tlu' antero-pos- 
 terior inspection of the ophthalmoscope. 
 \Yhere the papillary margin is visible it 
 shows extremely white. 
 
 The pecten also extends far above as well as 
 below the disc terminals and projects deeply 
 into the vitreous chamber. It appears by 
 the mirror to be a chocolate-brown in color. 
 Opaque nerve-fibre radiations are seen to orig- 
 inate at the disc margins, whence they cross 
 the background and finally disappear from 
 view at or near the periphery of the fielil. 
 
 Piciformes 
 
 SrLPiitR-BnEA.STED ToucAX. Rhamphas- 
 tu.t lamatus. As shown in Plate XLVT, page 
 105, this bird has a dull-gray eyeground (when 
 it is viewed ophthalmoscopically) rather regu- 
 larly spotted with whitish-gray dots. 
 
 The optic papilla is apparently composed 
 of short, coarse, white fibres which form a 
 sort of fringe all round its margins. Along 
 each of its sides and parallel to its long diam- 
 eter a few orange-red, choroidal vessels are 
 seen. Radiating from the papillary circum- 
 ference arc numerous opatjue nerve fibres 
 that extend to the fundal periphery across the 
 eyeground on all .sides. 
 
 The pecten is almost black-brown in color 
 and in shape resembles the same organ in the 
 Ilornbills and the Kingfishers, especially in 
 the former. 
 
 Above the end of the optic nerve entrance 
 and about half its length to the nasal side are 
 three dark-brown spots, clustered together 
 and surrounded by a small gray reflex. This 
 
102 
 
 THE FUNDUS OCULI OF BIRDS 
 
 area is probably the macular region; at least 
 it corresijoiids to its usual locality in other 
 orders and presents the characters one might 
 »xiM>ct, knowing the habits of the animal. 
 
 Ked-siiafted Flicker. Colaptcs mexican- 
 us. (Figs. 104 and 137; macroscopic view). 
 The ocular fundus of this species presents a 
 single fovea (or what in Man is called the 
 oteola) that seems larger than usual; at any 
 rate the central black spot is more pronounced 
 than in most Birds. It has no well-defined 
 macular ring but appears to have a place in 
 the uniformly dotted retina al)out half a disc 
 length above and slightly to the nasal side of 
 tiie anterior optic terminal. 
 
 The peden has seventeen double toils (34 
 single convolutions) on either side of a promi- 
 nent and rather deep keel or ridge that unites 
 them above. Of these coils two stand at 
 right angles to the keel, two are slightly curled 
 on themselves and present a concavity 
 towards the posterior free border, while the 
 remainder look in the opposite direction with 
 varying degrees of concavity. 
 
 Red-headed Woodpecker. Melanerpea 
 erythrocephalus. (Figs. 103 and 138; macro- 
 csopic view). The general appearance of 
 ihis fundun much resembles that of the Red- 
 shafted Fhcker. It is true that here the 
 macular field is defined by a boundary of faint 
 printed dots, but these are hardly distin- 
 guishable, except at the infero-nasal cjuad- 
 rant, from the pigment of the neighboring 
 retina. In the center of the sensitive area 
 is a single black spot surrounded by a cloud 
 of dark granules that are wanting lielow, in- 
 tended to depict Xhc fovea. 
 
 The pecten has 34 single convolutions. Its 
 structure also closely resembles that of the 
 Flicker just described, but the former is 
 larger, the folds are heavier, and the uniting 
 keel is wider and deeper. 
 
 (iiL.\ Woodpecker. Centurus uropygialis. 
 An ophthalmoscopic view of the fundus oculi 
 of this bird, as shown in Plate XL VII, page 
 167, shows it to be dull-gray tinted with 
 yellow, and nearly uniformly charged with 
 minute, gray dots. 
 
 At the superior termination of the optic 
 disc (on the nasal side) is a small gray depres- 
 
 sion, partly surrounding a central, well- 
 marked and glistening white dot. Within 
 this area are, also, several gohlcn yellow dots, 
 which can be seen only when the reflected 
 light of the ophthalmoscopic mirror falls 
 obliquely upon them. Owing to the limited 
 number of this species that Head and the 
 writer were able to examine it was impossible 
 to say whether the punctate deposits last 
 mentioned are nornud or pathological. Fur- 
 ther ii.vestigation of additional specimens, 
 both ophthalmoscopically and microscopically, 
 will be necessary to decide the question. 
 
 The outlines of the optic nerve entrance 
 are well defined, and the central area of the 
 papilla at its union with the pecten is dull 
 orange stippled with dark brown pigment, 
 like pepper grains. The papilla is fringed 
 with coarse white fib-is. A large nunil)er 
 of translucent nerve fibres radiate from the 
 edge of the optic disc on all sides; they be- 
 come fainter and fainter as they approach 
 the fundal periphery and finally disappear. 
 
 The pecten, of the usual chocolate brown 
 color, reveals several corkscrew convolutions. 
 It comes well forward towards the lens, and 
 presents a massive, club-shaped appearance. 
 In most respects this fundus picture re- 
 sembles the eyeground of the Greater Spotted 
 Woodpecker. 
 
 Great Spotted Woodpecker. Dryobates 
 vet Dendrocopus major. The fundus picture 
 of this species is seen as Plate XLVIII, page 
 167. The color of the eyeground is a uni- 
 formly dull but definite gray, interspersed 
 with a large number of small, gray dots. Be- 
 low the optic disc and pecten are a few faint, 
 orange-red choroidal vessels. 
 
 The optic disc is apparently built of a mass 
 of brilliant, white, opaque fibres, very short 
 and thick. In the form of radiations from 
 the margins of the papilla towards the fundal 
 periphery run many gray, opaque nerve 
 fibres, that appear to occupy a plane lower 
 than the white elements of the disc. 
 
 The pecten has three corkscrew convolutions 
 on the disc, while its lower part forms a club- 
 shaped mass of a deep chocolate-brown color 
 that appears to come well forward towards 
 the lens. 
 
THE FUNDUS APPEARANCES IN VARIOUS ORDERS OF BIRDS 103 
 
 Fig. 139. Western Mockingbird (Mimus polyglottoa Uucopterm) X U. 
 Macroscopic Appearances of the Fundus Oculi in the Preserved Eyes of Birds. 
 
lot 
 
 THE FUNDUS OCULI OF BIRDS 
 
 TlitTc sc'cins to he only one xcusitive central 
 etna. This single iniiciila is, as iisunl, on the 
 nasal sidf of the jH'cten and has the apiM-ar- 
 aiiof of a lirillii.nt, whit<', round dot, Ihi- fun- 
 dus surrounding it Ix-iiig a little darker than 
 the general color of the eyegrouiid. The sur- 
 rounding gray area makes the white fovea 
 stand well forward, almost as if it were actu- 
 ally situated in the vitreous. N'o reflex ring 
 can he se(>n around it. 
 
 Passeriformes. .-1. Mcsomyodi 
 
 Derby Tyu.vxt. Pilangus derhianu.i. 
 The fundus view of this species, shown by 
 Plate XLIX, page 169, represents ophthal- 
 moscopic examinations of thrif siH'cimens. 
 The six eyes of the three birds presented ])rc- 
 cisely the same ophthalmoscopic appearances. 
 
 The cyegroiini! is hliie-gray, everywhere 
 sprinkled with minute, gray dots. These 
 dots are .so do.sely packed in the upi)er half 
 of the fundus that they give it a distinct 
 silvery appt-arance. Running at right angles 
 to either side of the optic papilla are numerous 
 dull-white opaque nerve fibres. These arc 
 near together and extend well across the eye- 
 ground. 
 
 .\t right angles to the optic disc towards 
 the nasal side and a little above its superior 
 end is a dense, pale-blue, punctate mass that 
 appears to surround the fovea. A light-blue 
 reflex ring also encircles this area. 
 
 The optic nerre-entrance is long, narrow and 
 white. Its centre is stippled with a few- 
 brown pigment dots, and it is bordered all 
 around with symmetrically placed black pig- 
 ment granules. This t)igmented margin 
 varies a little in indi\ , .iials. The pi'cten, 
 long and narrow, extends well behind the 
 edge of the pupil so that a portion of it can- 
 not be seen Ihrougli the mirror. The upi)er 
 part is serrated but the lower half is more of 
 the corkscrew type. The color is the usual 
 deep, dull brown. 
 
 Passeriformes. B. Acryomodi 
 
 EuHOPEA.N Chimney Swallow. Ilinmdo 
 
 rustica. The ophthalmoscopic appearanci's in 
 
 this sp'-'-ies are shown on Plate L, page l69, 
 
 and dep.^t the erect image of the right fundus. 
 
 The general color of the eyeground is warm 
 gray, tinted slightly with yellow or bulF, and 
 covered with minute, dull, yellowish dots. 
 S<'veral pale orange (choroidal) blood-vessels 
 are seen near the up|H'r extremity of the optie 
 nerve-entrance. 
 
 There are visible two macular rrgion.i. one 
 on each side of and above the upiwr end of 
 the disc. They show as small brown areas 
 or dots in the eyeground. Surrounding the 
 temporal macula is a slight reflex, apparently 
 compr "d of minute, bright gray dots. Th(> 
 macuht on the nasal side is quite devoid of 
 this reflex-ring. 
 
 The optic papilla, long and narrow, tapers 
 at its uppi-r end. On either side of the disk, 
 and at right angles to it are a few, fine, dull- 
 gray opaque nerve-fibres. 
 
 The pccten is quite narrow at its junction 
 with the optic nerve, but it gradually beconu-s 
 wider and more ma.ssive as it approaches the 
 lens. It is of the usual chocolate-brown color, 
 and is convoluted. 
 
 Westebn Mockixgbihd. Mimun pohj- 
 glottos leiicopterus. (Figs. 105 and 139; mac- 
 roscopic view). In this fundus are s n two 
 sensitive areas. The area nanalia, lying above 
 and anterior to the superior end of the optic 
 entrance about half th',' length of the papilla, 
 is seen as a black spot capped on its temporal 
 aspect by a semi-circle of large pigment 
 grains. The whole macular region is not 
 only bordered by pigment but the intervening 
 zone is, in the nasal three-fourths, also 
 •sprinkled with minute granules. The area 
 temporalis is placed almost directly posterior 
 to but much farther from the upiier end of 
 the disc than the na' ' fovea. It is evidently 
 shallower, is less plainly outlined and the 
 foveola is not as large. [The black line run- 
 ning along the left side of the large figure 
 indicates that a segment of the globe has been 
 removed — to show the temporal macula.] 
 
 The very long, narrow pecten has 52 single, 
 compact convolutions thai everywhere hide 
 the optic entrance. A moderately deep and 
 wide keel unites the pectinate folds along the 
 upper free border of the pecten almost to its 
 junction with the superior, pointed end of 
 the disc. 
 
THE FUNDUS APPEARANCES IN VARIOUS ORDERS OF BIRDS 10« 
 
 I 
 
 Fig. 141. California Shrike (ianiM* iudoricianm gam6«/i) Xli. 
 Macroscopic Appearances of the Fundus Oculi in the Preserved Eyes of Birds. 
 
106 
 
 THE FUNDUS OCULI OF BIRDS 
 
 Amekican MocKiN(iuiRD. ilimun pnly- 
 (jlolton. The ophfhulinoncojx* showM the pn>- 
 valfiif colorution of the fundus in this .sfx-fies 
 to Ix- a clear, blue-gruy. Thickly scpttercd 
 over tlie background lire irregularly sha|)ed, 
 whitisli-gruy dots or granules that in the 
 upper s«'ctors of the fie!d give the fundus an 
 unusually bright gray appearance. 
 
 Xear the upper extremity of the optic 
 papilla and towards the nasal side is the 
 mnciild. Tli' area is darker blue than its 
 surroundings, while its centre (the fovea) is 
 marked by a bright white dot which, again, is 
 enclosed in a green reHex. This gn-enish 
 reflex-ring has a striated appearance, the 
 strii>> being (|uite translucent and convergent 
 towa-ds the/orfa centralin. 
 
 The opiic difc is long and narrow; the visible 
 portion is brilliant white and its margins are 
 traceable on either side the whole length of 
 the pecfen. Radiating f'.nm the boundary 
 of the ner.eliead are many long, opaque 
 nerve fibres that extend over the cyeground 
 to its periphery. 
 
 The perten is, as usual, of a chocolate-brown 
 color; it is long, .■somewhat club-shaped and 
 extends well behind the margin of the iris, 
 so that its outlines are not entirely visib'*? by 
 the mirror through the undilated or only 
 partially dilated pupil. 
 
 The fundus of the Cuban Mocking Bird 
 (J/, orpheus) is similar in every resjiect to 
 that of Mimu9 polyglotios. 
 
 Bluebird. Sialia siaHs. This was one 
 of the earliest species examined ophthalmo- 
 seopically by the writer, and he was so struck 
 by the wonderful blue coloration of the ocular 
 background that the question arose in his 
 mind as to whether there might not be some 
 connection between plumage tints and fundus 
 colorin;-,. That query was soon answered in 
 the negative but the beautiful blue shades 
 in the eyegiound of Sicdis are still to be 
 admired. 
 
 .\s seen in Plate LI, the ophthalmoscope 
 shows that the general blue-gray coloring of 
 the eyeground is modified by numerous, pin- 
 point dots. The punctate deposits near the 
 I>eriphery assume a more or less dull-golden 
 or orange tint, a condition also noticed just 
 
 below the pcctcn. The elongated, ovoid 
 optic disc is white (quite woolly a I its margins) 
 and covcr-d almost iiitirely by the convo- 
 lutect pecton, which is very large when com- 
 pared with the size of the eye. A portion of 
 the unusually extensive jx-cten cannot \te 
 si>cn through the small pupil. It is of the 
 usual dull-brown color, and has "frilled" 
 borders. On the inner ■ r nasal side and near 
 the lower part of the optic disc is an orange- 
 red area, containing chieP.y choroidal vessels 
 with black pigment grains betw»>en them. 
 This red area extends a little to the temporal 
 side of the disc, subsequently merging into 
 the dull orange color below. On either side 
 of the disc and radiating from it, are numer- 
 ous filiform nerve fibres which cross the back- 
 ground almost to its periphery. In an area 
 a disc-length to the nasal side of the papilla, 
 the white dots of the fundus are fainter and 
 much closer together than elsewhere; and in 
 this region, also, there is a reflex plainly 
 marked. Here, if in any part of the fundus, 
 is the fovea or macula, but it is not sufficiently 
 well defiled to he certain of it. 
 
 Figures 106 and ! 10 demonstrate quite con- 
 clusively that in the fundus of Sialia sialia 
 there are two macular areas, symmetrically 
 placed above and on either side of the pointed 
 eiid of the papilla. The area nasalis is removed 
 about half a disc length; the/or«a temporalis is 
 somewhat more distant from the same point. 
 The nasal macular region is liirger and more 
 plainly marked; it is surrounded by u dotted 
 ring, incomplete above; the corresponding 
 foveola is represented by a black spot crowned 
 by pigment grains. More than half the inter- 
 vening zone is lightly strewn with minute, 
 dark granules. 
 
 The heavily-built pecten is composed of 19 
 thick, rounded, double folds — or 38 con- 
 volutions. A comparatively massive, paddle- 
 •shaped crest surmounts these and extends 
 along the whole of the upper free border. 
 The major axis of the papilla makes with a 
 line joining the two foveolee an infulapapillary 
 angle of about 70°. There is nothing to be seen 
 of the nerve head from above. 
 
 Wheateak. Saxicola <Bn .une. The color 
 reproduction shown in Plate LII, page 171, 
 
THE FUNDUS APPEARANCES IN VARIOUS ORDERS OF BIRDS 
 
 107 
 
 furnishi's an i-xart virw iif the nphllialmo- 
 xropic npix-iirniufs ot' the fiinilus iK'iiIi of tlii.t 
 .s|)«'cii'-t. It is of (lie left cyr, crt'cl iliiaK<'. 
 Th<- K*'>><'>'i>l fiiiiilal coloratioii is paU- ^rny, 
 with a (li'iisc mass of uriiyisli whiti- tlols 
 |KTnifatiii^' the I'litin- 'lackground. 
 
 Sli){litly aliiivc tlic upiMT tcrniiriation uf tho 
 optic mTVc, anil towards the nasal sidt" of the 
 |M'ftfn, is a wi'll-dcfiiicd, round, white an-a, 
 (tlif iiiiiciilii i'nd f<vei!) much larger tlian the 
 small spots tiiat cover the whole of the sur- 
 rounding, duller eyeground. This white area 
 is inclosed Ity a brilliant , bluish-green circle, 
 which appears more prominent an<l iridescent 
 in nature than is depicted in the drawing. 
 
 Little can he seen of the opiir papilla he- 
 cause it is almost entirely obscured by the 
 IK'cteii. However, it is long and nn'row, with 
 an irregtdar outline. 
 
 On the nasal side of ti.e nerve-head are a 
 few short, orange-red, choroidal blood-vessels 
 with a few dots of pigment, like jH-pper grains, 
 sprinkled belweep them. Extending from 
 both margins of the optic disc across the 
 fundus to the periphery, arc numerous fine, 
 opa(iue nerve fibr»'s, the upper ones (on the 
 nasal side), terminating at the macular area. 
 
 Till' pecten, red-brown in color, long and 
 narrow, appears to be twisted on itself like a 
 rope or a corkscrew. Its inferior end extends 
 lieyond that part of the eyeground shown in 
 the picture, but it probably comes well for- 
 ward towards the posterior surface of the 
 lens. 
 
 English Nightingale. Aedon megaryn- 
 cha. The ophthalmoscopic appearances of 
 this species is almost identical with those of 
 the Wheatear (see Plate LII, page 171), ex- 
 cept that in Saxicola the macular region is 
 not so well defined. 
 
 Califounia Shrike. Lanius Indoricianus 
 (jambeli. (Figs. 107 and 141; macroscopic 
 view). 
 
 There are hro macular region' in the fundus 
 of this bird, similar in every detail to the same 
 area; in the Bluebird. 
 
 The optic papilla is, however, longer and 
 soniewliat narrower in Lanius, and the more 
 extensive pecten exhibits folds joined along 
 its free borde- by a rounded crest that from 
 
 above takes on the shape of n carrot. The 
 major axis of the Ioi;<i ovoid <lisc projected 
 until it meets a line crossing the floor of the 
 (■oncave fimdus .in<l joiii :g the two fovcohe 
 would subtend an (infulanapillary) angle of 
 about 110°. 
 
 Passerifo.'mes. li Alaudidae 
 
 EfnoPEAxTiTLAiiK. Atiihus proknnK. A 
 healthy adult male individual of this .s|M>cies, 
 about three months in captivity, obtained 
 from u dcal'T, was examinei, by the writer in 
 the laboratory of St. Luke's hos|iital. The 
 pupils were unaffected by one drop of a 1% 
 sol. of atropia instilled 48 hours previously. 
 The bird was strongly hyperopic and very 
 slightly (about 0.33 D.) astignuitic, the skia- 
 scopi" showing 3.30 D. of HAS in each e,\ •. 
 
 The ophthalmoscopic examination revealed 
 no opacities in the ocular media. 
 
 The pecten is of the usual black-brown 
 color; it is large and spiral, filling the whole 
 pupillary area when examined with the mir- 
 ror, and almost entirely obscures the outline 
 of the optic papilla from whicn it springs. 
 
 The background is of a fine, p<'pper-and- 
 salt character with a very few opaque nerve 
 fibres radiating from t'lc disk. Scattered 
 over .!ie field are man; bne sparkling points 
 like minute grains of cholesterine. These 
 are also to be found in the macular region, 
 which is definitely outlined directly in the 
 axis of vision and covers a space about J 3 of 
 a disc-len>;th. The mirror does not show a 
 second area of acute vision. 
 
 Passerifonnes. B. Fringillida 
 
 Bkitish Linnet. Linoia cannabina. The 
 indirect ophthalmoscopic examination of an 
 imported individual, in captivity a year or 
 less, shows a jwctep 'hat obscures a view of 
 the fundus details, but the prevailing color 
 of the eyeground iy readily seen to be ,1 beauti- 
 ful, light, gray-Mue beset with whitish dots. 
 
 British Gcldfixch. Cardueli.i elegans. 
 The fundus 01 this bird as seen by the indirect 
 method — it was extremely difficult and un- 
 satisfactory to make an ophthalmoscopic 
 examination by the erect image — showed an 
 eyeground that resembles that of the Linnet 
 
108 
 
 THE Fl'N'DUS OTl'LI OF BIRDS 
 
 Fig. Hi. Atiieriuin Oow (Conua amerii-aniu) Xh. 
 MwToscopic AiiiK'ftrBncfs of the Fundus Oculi in Ihc PrfStTved Eyes of Birds. 
 
 in J>eing uniformly lij,'ht liluc-griiy. Tlic 
 IX'cten obscun-il most of thi- field. 
 
 BniTi.>iii SmKiN. Chn/somitris spiiiun. 
 One of thi.s species, obtained from n dealer 
 and said to have l)een captive for si.\ months, 
 was examined by the indirect method throuKli 
 the small and undilaled pupil. There was a 
 relatively large pccten which made it impos- 
 sible to outline ' he optic nerve-entrance clear- 
 ly or to (letern ine the fundus details. How- 
 ever, the prevailing color of the eyeground 
 was light gray-buie, more or less regularly 
 besprinkled with minute, yellow-white dots. 
 
 HorsE Si'.\nnow. Panser domesticiis. 
 The ocular fundus of ihis typical sj;'jcies is 
 pictured as Plate LHl, page 173 the result 
 of the ophthalmoscoj)ie examination of numer- 
 ous specimens. The dominant coloration of 
 the eyeground is pale-gray covered with very 
 fine white dots, closely packed together at the 
 mae!ilar area. They form a lighte- Kone a 
 litils above the upper extremity of the pecten 
 
 and towards the nasal side of the disr. Frnm 
 the circumference of the optic disc a large 
 numlK-r of rather long, opa<|ue nerve fibres 
 run in radial fashion towards the periphery 
 of the fundus. 
 
 The papilla appt>ars, when visible, to be 
 composed of irregularly shaped, brilliant, 
 white bundles; it can barely be outlined with 
 the mirror except at the upper (and narrow) 
 end of the p<'cten. 
 
 The pecten has a de<'p red-brown color, and 
 its free extremity is long, narrow and of the 
 corkscrew type. The lower segment of the 
 organ extends well forward towards the lens 
 and, being large and massive, completely 
 covers the pupil and makes it impossible to 
 obtain a lateral view. 
 
 Vakiei) BuNTiNO. Cynnnspiza versicolor. 
 Plate LIV, page 173, represents the ophthal- 
 moscopic appearances of this species. The 
 prevailing color of the eyeground is dull gray 
 shading to buflF. It is covered all over with 
 
TIIK Fl \nrs ArPKAHANCES IN VAHIOIS ORHKHS OF IIIIIDS 
 
 ion 
 
 «<r.v ininiitc. »:rii.vi<.|i-»liili- ilnt^. TlicfM- dol* 
 coiili'M'f III till' tiKiciilii »lnT«' IIh'.v form ii soft, 
 nmml nrrii linrilcn-tl liy ii li(,'lil rcllcx. Ti .• 
 Hiri^lr rriHi'iihir rrKioii iinil fiivni iir<- ><iliiiili'i| 
 a litlli' iil>ii\< the u|)|H'r t'lifl of tlir (H'tl'ii hihI 
 tnwiinl'* tlic niiiiil »i<U' of llif opiic !,■ rvc. 
 The i>irltn, vtTV liirjp' mid tim,«.sivc for Ihc 
 »i/i' of tlir ryr, is of the ii^iiiil cliocolitlr- 
 hrowii I'olor; it is niort' or less ('IiiIi-s|i;i|m'i1, 
 mill I'xlcnils Well fiirwiiril lowiinis the lens. 
 At liiiK-s it (|iiit< (ills the iip'ii of Ihi' |>iil)il, so 
 thill I lie fiiiiiliis is ilillii nil |o t-xpion-. Tin- 
 p«'«'tcn, whose outline in very irrcKu!ar, covers 
 the piipilla entirely so that it iip{MNirs to 
 spriiiK (lircclly fniiii the retiiiii without show- 
 ing the while disr iiiarK'iri found priicticiilly in 
 all birds. I'Vorii the sides of the iippnrent 
 root of the |H'eten a few, whitisi.'. opa<|Ue 
 nerve filin's jtoss the field of vi<'w. 
 
 Passerifotmes. Ii. Tanagridir 
 
 Sc.Mii.KT TwAiiKH. Pirimgn rrylhromrlan. 
 The dominant coloration of the eyejrround \v 
 this sped' — readily M-en hy aid of the in- 
 direct method — is a clear, hriffht gray- 
 hrown, .sprinkled with numerous, glittering 
 whitish-yellow points. 
 
 Law Hiud of Pauadise. I'nrolla lairli. 
 I'lale LV, page 17ii, gives an ophthalmoscopic 
 picture of the fundus of the left eye, erect 
 image. 
 
 The cycijround apfK-ars yellowish gray, or 
 khaki color, almost uniformly covered with a 
 dense mass of minute white dots, thiut are 
 smaller and deu.ser at the macular region. A 
 few <lull-red choroidal capillaries an- visible 
 on the lower part of the fundus near the 
 jwriplicry. 
 
 The oplir nerve head, dull-white, long and 
 narrow, has a rounde<l up|ier end. Its entire 
 central area apiiears •■■. if it wen- a mass of 
 fine, I Town pigment dots. 
 
 The perten is exceptionally long, rather 
 narrow, spirally arranged and extends beyond 
 the range of vision through the undilated 
 pupil. It i.s similar in many respects to the 
 fundus of the Common Pigeon. 
 
 To the nasal side and a little above the end 
 of the disc is the macular region, which .'ppears 
 us a dull-brown, crater-like depression bound- 
 
 ed by a white mass of (reflex) strialions. 
 Opaipie nerve fibres radiate from both siiles 
 of the di-c but finally disa|i|)ear as they 
 approa< Ii the boiiiiilaries of tlu' fundus, 
 
 Pasierlformes. ( 'nrridir 
 
 Ulik Jav. ('iinniM-itlii erintaln. The fun- 
 dus ap|M-arances as ri-vealed by the oplilhid- 
 mosco|M' ill the left eye of one of this s|M-cic > 
 is depi<led as I'liite L>I, page 17.V The 
 gi-neral color of the eyegroiind is a slate-gray, 
 with an added pale-yellow tint in the lie er 
 half of th.- eyegroiind. The entire •'■•l-l n 
 Ix'spriiikled with irregularly sha(" +- 
 
 gray dots, giving it the iip|H'' < J| 
 
 and rather coarse surface, es|H-<iall; j« 
 
 macular area win re the dots are iin -^ 
 
 packed in the shape of a bright rr,f 
 
 patc'i. 
 
 The optir nerre-head is quite 'vhii ..f 
 
 oblong shiifx'. Several orange-ccl'x o- 
 
 roidal capillaries are visible i i ifn i;ion, 
 covered with minute, brown, piprc dots, 
 liki black iM'pjM-r grains. Sprint I iboiit 
 each side >:' the optic disc is n large i.ainiber u( 
 opaque nerve tiincs that cxtenif across fl' 
 fundal field. 
 
 The perten, of the usual cboei U»to-t(ri.«ii 
 color, is rather irregular in shajx- ; it< .«u|!' 
 rior extremity. From above <i- wnwani >=- 
 looks lii.e a tarred ship's . bec'-miBjE 
 
 larger as it approaches its .ii wit, t'n- 
 
 papilla. The length and lit; .iiess o{ h; 
 organ ^compared with the si/r ,,f the eye *r 
 pupi! make it diflicult to follow its out >i-. 
 throughout. The superior end apiX'iM 
 come well into the vitreous cavity iin'i l<, 
 reach the lens. 
 
 Stkllkii Jay. Cyanocitta ulelleri. (Fig 
 111 and 10!); macroscopic view). The ocula; 
 hack-ground of this siM-cies exhibits a moderale- 
 .sized, though well-marked, single, circular 
 macular region. 'Dwforeola is shown as a dark 
 spot crowned by minute pigment grains thai 
 mingle with a similar jiignient ring of granules 
 that .serve as a boundary for the whole region. 
 There is a small, kidney-shaped space lc- 
 tween these two collections of dotted pig- 
 ment that .seems free of color. The centre of 
 the fovea is slightly above and about half a 
 
 .(^^)><f»iii9C'uazm^ '.nejrtr, 
 
no 
 
 TlIK FUXDl'S Ornj OF BIRDS 
 
 Hiiw-lenKth from f hr anlrrinr rtid cif the nptic 
 riilranir, 
 
 Th)* lonit nml wide prrlrn hait A4 Kinglc coii- 
 vi)luti()ti!<, and in Nhapr n-M^nililrx I lie nanw 
 iirKiin in the t irikf, rxrcpt Ihiit from the 
 <vnl<T of itit cTTNt ri»r» a iihort spint- cnxily 
 Mfn in l)'>th fiKurrii. Thr optic papilla i.n 
 nlnioxt ronipletely hiildcn by the niaiw of the 
 niar!«upitim. 
 
 Amkhican Chow. Ciirrut anifriranuf. 
 (Fi«."t. lOH and 144; macroscjipic view). Thon- 
 is in the bark((round of thin .s|>pcif.H an nn-a 
 of a<'Ul»' visual prrtvption r«'pr«'!M'nle<! Iiy a 
 retinal bar or hand at wIiom' middle |M)int in 
 Mfn a w»-ll dj'fineil/orf a, the <Tnter of a macu- 
 lar region formed l>y a widening of the hand 
 itM'If. The hand stwtelii horizontally acroits 
 the fundu's and ii centrally Icx-ated >n the 
 field of view. It is of medium width, out- 
 lined hy a uniformly dotted line above, but 
 less iiistinctly Ih-Iow hy a string of minute 
 granules that more or less tint the lower half 
 of the band itself. The macular region is 
 formed liy a widening of the sensitive hand to 
 form an oval-shaped region. 
 
 The superior ei.d of the papilla is one-half 
 its length from the foveola. 
 
 The large pecirn (thnn'-fourths the length 
 of the retinal hand) is formed of about 61 
 uniformly compressed convolutions joined 
 at their free margins, above, by a shallow, 
 dumb-l)ell-shaped crest that slopes gradually 
 from h«>hind forwards. 
 
 If the major ixis of the papilla — obscured 
 by the pectiua ■ mass — were projected to 
 meet the temporal end of the retinal bur it 
 would describe an (infulapapillary) angle of 
 about 60°. 
 
 EinoPEAN Cahhion Crow. Corrus 
 corone. The writer examined in the Labora- 
 tory of St. Luke's Hospital, Chicago, an 
 adult male of this species, imported from 
 Germany. He ha<l In'on in captivity about 
 a year. Boti eyes w, re healthy. He used 
 his nictitating membrane freely on the ap- 
 proach of light 'o the eye. The pupils varied 
 in diameter fi im 2 to ;.50 mm. A single 
 drop of 1% solution of atropine sulptiate info 
 each eye produced no effect on the ^ize or 
 movements of the pupils during the following 
 
 4H hours. The same negative rmult waa ob- 
 tained hy the u<«e of a one-fifth per cent solu- 
 tion of hyimein and by a mixture of honiatro- 
 pine and cocaine. Skiascopy in the dark 
 rtMtni showed, iHith liefore and after the use 
 of atropia, a hy|M>ropia of 41). 
 
 Hy the dir«H't method lh«' l-irkgrouml 
 ap[H>ars to Im> almost uniformly dark red- 
 brown. The macular rrgiim is set-n with 
 difficulty. 
 
 The oplic difc is a long, while oval with 
 the pecten a very black, corkscrvw-like organ, 
 appar«>ntly changing plan* and shape rapidly 
 under examination. 
 
 Common Uhitihii IlLArKBiRD. TurduK 
 merulii. The ophthamo.scopic picture of this 
 sjM'cies is repro«Uice<l as Plate LV'II, page 177. 
 It shows the eyeground as seen in the left eye 
 by the direct methcMl. The general tint is a 
 slaty-gray with a uniform sprinkling of tiny, 
 white dots. There is no visible macular 
 region, hut tiie whole fundus is covered and 
 i; :>loring greatly modified by minieroits, 
 linear, opaque fibres that ari.se from the di.sc 
 margins throughout and run across the entire 
 fundus to the extn-me periphery. A few 
 faint, yellow-red choroidal vessels are seen on 
 either nAv of and paritllel to the moderately 
 long and narrow papilla. The upper two- 
 thirds of the disc is aliout half covered by the 
 club-shaped pecten, Vvhich is apparently com- 
 posed of very few folds. The massive, choco- 
 late-colored, posterior end of this organ en- 
 tirely obscures the lower third of the nerve- 
 head, while the upi)er half of the former has 
 a light brown niargiii on its nasal aspect, and 
 seems to be only in part attached to the nerve- 
 head beneath it. 
 
 Raves. Corvuscorax. Thf fundus picture 
 (right eye) shown by Plate LVIII, page 177, 
 represents the (similar) appearances in a 
 number of specimens examined with the 
 ophthalmoscope by Mr. Head in the London 
 Zoological (iardens and hy the writer in the 
 aviary of the Bronx Park, New York. 
 
 The eyeground is a light fawn sprinkled 
 with dots about three shades darker than the 
 ground color. Mixed with the dark dots 
 are numerous white ones, seen especially when 
 a strong light is thrown upon the fundus. 
 
THE FI'MUS .\IM'f:.VI«,\\( KS IN VAHIOI S OHDKHS OF HlllDS III 
 
 MmmiI HiriT iliM-hniiiltliH from ijir iip|Nr Ihr lnwi-r part of tin- fiiii,|i„. ,u«NiiiliMl «itli 
 
 mil of thr ilioc on Ihi' iiiiirr >ii<l.' \n a «.ll iitniiiilMrof nraiitft-rid ilols.nn- a fi« oni 
 
 iirknl liriKlit n-lliA of a unTni-li-l.l 
 
 UK"'- 
 
 liliK<'. It ii irri'Kiilarly oval in >lia|M' aii>l lallrr In 
 m-i'iiii* to Ik- ('oiii|H>Hi'<t of a iiiinilM'r of very 
 
 ml rlloroiilai IiI<hh|-vi"<-.i-I'<, ti'ViTnl of III) 
 
 I ill- <liM'. 
 
 iiiK iliilriltiili'il alonx lillirr liilc of 
 
 liiif filircv,. Ill flic (riittr of till- r< llix is lli. 
 
 Tlir /i.(7.»i.» ill all llic Ha\iii^ iA;iiiiiin<l 
 
 «i./n//(i. a small, ilark. iralir-lik.' .'.iirt'sMon, win- of similnr slia|)c iiml of llir iiMial ihirk.- 
 
 lirowM ill i-olor. Till- liiv is chalky uhil 
 mill K>V('!* one till- impression that il is nui 
 
 |M>si-f| of many opai|iii' lurvi- lilins p.nknl liny approai linl llii- Inis »h«rr II 
 i'los«'|y foK<' 
 
 From Ihr (list ma 
 
 iirowti nilor. Tlicy «i ;. vi-ry lliiii ami nar- 
 row al Ihr ilisc liiil assiininl a i'liili-slia|M' as 
 
 irv «i r<' 
 
 llicn- ratliatf .. niinilH<r of (i 
 fihrrs that cxti-nil in ross I hi- cv 
 
 rKiiis 
 IK- o|)li<' iirrvi' 
 
 I'Kroiiiii 
 
 I. Il 
 
 clarkiT in color. Tlic |k'cIcii comes will 
 forwaril ami ap|M'ars at limes In press hk"'""'' 
 the |M>sicrior capsule of the lens. 
 
 _1 
 
Chapter X 
 CLASSIFICATION OF THE OCULAR FUNDI OF BIRDS 
 
 The piirlicoldrcd avian l)a('knr()und, as sct'n 
 liy the oplithalnioscopp, although of groat 
 variety, may he (lividcd into two major 
 calt't^orios and racli of tlu'so into five sub- 
 divisions, as follows: 
 
 A. Tlie iirasriilnr fiiiKlKn, in wliich thort- 
 art- no visit)l<" n tinal or choroidal blood- 
 vessels. 
 
 This elass resolves itself into (a) those 
 avascular eyeprounds in which the predomi- 
 nant color is llfihl (jraji or (jratj-hluc. These 
 fundi are comparatively rare, but examples 
 of them are found in the Varie<i Bunting 
 (Plate LIV) and the Iin-eaha Rail (Plato 
 XIII). 
 
 (fc) Dark lira;/, drcp grati-bhiv or slale- 
 rolorcd arasnihir fundi are ((uitc common. 
 The llarle(|uin Quail (Plato VIIl), Knplish 
 Sparrow (Plate LUI), Derby Tyrant (Plate 
 XLIX). IJrush Turkey (I'lale VII), Varroll's 
 Curassow (Plate VI), Sulphur-crested Cocka- 
 too (Plate XIJ), and the European Bittern 
 (Plate XXI) are samples. The fundi of the 
 (reeled Coot (Phile XII) and of the Black 
 lloriibili (Plate XMII) bohmg to this sub- 
 division but they also show u greenish tinge. 
 ((■) YcUnir. oraiirjc and nrangc-rcd bloodless 
 fundi belong almost ex( lusively to N'iglil 
 Birds, or to thoM' that use their eyes for 
 both diurnal and tioiturnal visualizalioii. 
 Such fundi are seen in the .\i)tcryx (Plate 
 IV), Camiet (Plate XXIX). and tli.' Black- 
 fooled Penguin (Plate XIN). Tie corrcs- 
 piinding elass of rascidar fundi is a inu<'h 
 largir one. 
 
 ((/) Fundi of a hnnrnish or ru.isil roliir. 
 slioirinfi no rascuhtr sni)i>lt/. are ralher com- 
 mon. Examples are sei'n in the .\ma/on 
 C.oiden Parrot (Plate XXXIX), South Amer- 
 
 ican Ostrich (Plate II) and tlio Cassowary 
 (Plate III). 
 
 ((•) Bicolorcd or muUicnlorcd fundi dcroid 
 of risihic hlood-rcssels are but infre(|uently 
 encountered. The fundus of the Nubian 
 Ostrich (Plate I) is mostly of a light chocolate 
 shading to red; also the Bluebird (Plate LI) 
 exhibits a background mostly light gray-l)lue 
 but has also a small red-brown area or zone 
 dotted with l)lack. 
 
 B. The rasrnlar fundus oculi is one in 
 which the choroidal rnpillarics show more or 
 Icsx distinclhj. In some instances the blood- 
 vessels are barely visible; in others they 
 cover the whole background and are the most 
 conspicuous objects in it. The vascular fun- 
 dus is subdivided like the avascular back- 
 ground. 
 
 (a) Lii/lil ijrai) or gniii-hhir fundi, more 
 conmion than A (<;), arc found in the Wheat-ear 
 (Plate LID, the Cormorant (Plate XXVIII), 
 and the Glossy Ibis (Plato XXIII). 
 
 (/)) Dark gray, drcp (iroy-hlur or slalc- 
 colorrd vascuUir fundi constitute the com- 
 monest exami)les of colored fundi so far s<-en 
 by the writer. They are found, among 
 others, in the European Cuckoo ( Plate XLV). 
 the Wonga Wonga Dove (Plate IX), the 
 PuHin (I'latc XV), Sulphur-breasted Toucan 
 (Plate XLVl), Spoonbill (Plate XXV), Croat 
 Spotted Woodpecker (Plate XLVIID, Blue- 
 crowned Jay, with a greenish tinge (Plali- 
 LVD. Common British Hla<kb;,,! (Plate 
 LVID, the Night Heron (Plato XX), Ameri- 
 can. labiru (Plate XXIV), Law Bird of Paradise 
 (Plate LV), Lammergeier (Plato XXXII). 
 
 (c) Ycllon\ orange or nriiiilion fundi show- 
 inij choroidal Mood-rcsscis are, as in the .V'f' 
 class, found almost entirely in birds with 
 
 \U 
 
CLASSIFICATION OF THE OCULAR FUNDI OF BIRDS 
 
 113 
 
 nocturnal habits. Amoiij; them are the Bra- 
 zilian Boatbill (Plate XXII), Kakapo (Plate 
 XL), and the Barn Owl (Plate XXXVIII). 
 
 (rf) Vascular fundi whose general culora- 
 Hon is brou'n, brownish or russet are also fairly 
 common. The White-bellied Sea Eagle (Plate 
 XXXIV), Gila Womlix-eker (Plate XLVII). 
 LanRhinK Kingfisher (Plate XLIIi, Little 
 Bustard (Plate XXXVI), Raven (Plate 
 LVIII), Stone Plover (Plate XVII), Creat 
 Blackbacked CIull (Plate XVI), Blue Snow 
 (Joose (Plate XXVII) and the Chimney 
 Swallow (Plate L) are among them. 
 
 (p) liieolored or mullivolured raseulur fundi 
 are commoner than those classed under A (c). 
 The vascular eyeground of the Martiiieta 
 Tinamou (Plate V) is brownish below and 
 light gray above; its color scheme reminds 
 one of the ocular background (when seen 
 ophthulmoscopically) of some nuimmalian 
 fundi. The Australian Pelican (Plate XXX) 
 has a fundus ocidi which is russet below 
 gradually shading to grayish above. The 
 eyeground of the Kagu (Plate XVIII) is also 
 reminiscent of mammalian color mixtures; the 
 lower half of the background is a well-marked 
 red-brown dotted with black pigment, while 
 
 the upper segment is a sky blue. The lower 
 two-thirds of the fundus oculi of the Brazilian 
 Serieina (Plate XIX) is biownish, the upiH'r 
 third slate-blue. The Bald Eagle (Plate 
 XXXIII) has also a mixed fundal coloration; 
 being dull red-brow n below and mottled gray 
 above. Finally, the eye of the nocturnal 
 Nightjar (Plate XLIV) mimics to some extent 
 thefini<lal color distril>ulion in the background 
 of certain of the night-in-owling niamn'ali.in 
 Carnivores, being dark orange-red below and 
 light orange above. 
 
 In the above classification the colored dots 
 that hesprinkle the fundus picture of practically 
 all Birds (and represent, probal)ly, the colon-d 
 droplets of the retina) are not considered. 
 However, both <lirectly and by contrast they 
 greatly modifj the color impression made 
 upon the observer, and especially when they 
 are large and numerous, iuHuence the general 
 chromatic elfect. In some instances, their 
 number and distribution are su:li as to detir- 
 mine the verdict of a first glance, anil the 
 observer nmst be on his guard not to mistake 
 the.se accessory pigment points for the solid 
 background of color which one fimls in all 
 avian fundi. 
 
ClFAITER XI 
 
 THE OCl LAR FUNDUS OF BIRDS IN ITS RELATION TO 
 A CLASSIFICATION OF AVES 
 
 TiiF. writtT is well awaro of the controversies 
 >o easily ])rov(ikeil in that zoological storm 
 centre, the svstennilic clas>ificalion of Hinls, 
 lint he believes that as the fnnilus appear- 
 li.-es in wild species ,ire probably invariable 
 and that, as the evidence so far produced 
 shows, each species exliil)its a bnckgronnd 
 picture distinct in one or more particulars 
 from every other specii's, it is possible to 
 identify many of them by the use of the oph- 
 llialmosco|)e alone; in other words, in the 
 classification of Hirds the fundus details, 
 including the varied coloration of the eye- 
 ground, should Ih- considered quite as mudi 
 as the histology of any organ or division of 
 tlie body. 
 
 The extent to which these taxoiiomic indi- 
 cations correspond to the orders ui any par- 
 ticular classification cannot, in the absence of 
 a complete or nearly complete investigation, 
 now l)c determined. In the opinion of the 
 writer, however, there are certain facts that 
 have arisen in the course of this preliminary 
 research tliat are worth discussing for the light 
 they throw upon and tlii aid they may give 
 to a systematic arrangement of avian siK-cies. 
 
 That the eyegronnds of the Riililc orders 
 present peculiariti<'s that distiiigui:h them 
 from I he (uriitiitir is evident at a glance. On 
 the iilher hand tiiere are the usual ditfcrences 
 belwcen the acarimite species. The colora- 
 tion of the fundi and the characters of the 
 pe(t(iis in Khea ( I'lale II) and Slrulhio 
 (Plate I) bear a close resemblance. The 
 ocular fundus of the Cassowary (I'late III) 
 is more I iosely "Hied to that of the Kiwi than 
 to the Nandu. The ocular background ol the 
 Tinamou is decidedly ucarinate and this fact, 
 
 with otlaT taxonomie indications, justify, 
 from the ophthalmoscopic viewpoint, its in- 
 clusion in that subclass. 
 
 The Apteryx is so decidedly a nocturnal 
 animal ^especial'" in the use of its eyes for 
 distinct vision boi. in the distance and near 
 — that one is not surprised to see so much 
 ye''iw in its fundus coloration. There are 
 s- V exceptions to the rule of the yellow- 
 ci,.,.red fundus in Night Birds that one nniy 
 confidently assert that the amount of this 
 color in avian (one might say in all verte- 
 l)rate) fundi is in direct ratio to the propor- 
 tionate use a given species makes of its visual 
 powers after sunset. When a bird and his 
 ancestors (in tlu" evolutionary sense) have 
 used their eyes for distinct visualization 
 largely or exclusively at night the fundus tint 
 is nearly always yellow or orange. 
 
 Ap|)lying tliis rule to carinate Night Birds 
 we find many consistent and nnirked ex- 
 amjjles of it. For instance, all the Strigi- 
 formes so far examined have a preponderance 
 of yellow in their eyegrounds. Without 
 carrying this assertion too far we note that 
 in semi-nocturnal Owls, like Slrix flainmea 
 {Plate XXXVIII), the red tints overpower 
 the yellow and a shade of orange results. 
 
 Still more suggestive are the fui<dal con- 
 ditions seen in the Owl Parrot, Stringops 
 hdbroptilii.i (Plate XL). Compare the fun- 
 <lus, esjK'cially its yellow color and the posi- 
 tion of the (temporal) area eenlr'jlia, first 
 with that of any Owl and then with I'sittieim 
 (iiniizona; undoubte<lly, so far as the eyes are 
 concerned, they belong to the former. 
 
 .\nother observation of avian fundi seenis 
 to show that an admixture of yellow (in the 
 
 114 1 
 
CLASSIFICATION- OF AVES AND THE FIXDIS (KTLI 
 
 form of an oriniffe-rcd cDloration) may Ix- 
 pn-sciit til inilicatf mil sii inucli ri'cciit as 
 fornuT, i.e. atavistic, iii)j;ht liiilills intin ^in(■^■ 
 aliaiiildiicil liy the spcrics. 
 
 Tliis aliiKist uiiivfisal (icourroiicc (if yclldw 
 <ir (iranK<--litil<'il fundi in XiKlit Hirds leads 
 <in<> to spccnlatc as to the cause .if a dlirerent 
 coloration in species that, ilurinf; historic 
 times at least, have Used their eyes larj,'ely or 
 exchisively after ihirk. At least >nnie of the 
 Ardeiformes fiirnisli such examples. The fun- 
 dal colorinj,' of \)/(iin)r(U- inictininti (Plate 
 X\) has no yellow in it ; nor has the Hoatliiil 
 iCiinrriiiihi ri,fhl((iri(i). allhoiii;li lioth fundi 
 are evidi nlly so cJoNely allied that one might 
 well lielieve that tiiey are liotli Herons. 
 Proliahly the .\ight Herons have adopted an 
 
 115 
 
 ex<-lnsively iKK'tnrnal lif«- at sikIi a recent 
 Keoloi,'ic period llial the evolutionary tissue 
 changes necessary to produce the yellow fun- 
 dus tints liave not yet lieeii liroujiht alioiit. 
 The same remark is applica'ile to the Hit tern 
 (Plate XXI). 
 
 So far as exann'ned, the decidedly nocturnal 
 CaprinMil^ridie also have yellow or oran^'e 
 fundi. The eyeground of the Furojiean 
 -NiKhtjar (Plate XLI\') is a conspicuous and 
 lyjiical examiile of the colored finidns of a 
 true Xij;ht-feedin;; liird. 
 
 The arranjienient of the centres of distinct 
 vision, the fundus tints and the pectinate 
 tissues of the lar),'er Acciptrifiirmcs present a 
 decided (iphthalmoscopic resemlilance in ail 
 the sjH'cies so far <'xaniined liy tlie writer. 
 
CHAPTKR XII 
 
 RELATIONS OF REPTILIAN TO AVIAN FUNDI 
 
 The colored illustrations of three eyegrouiuls 
 of reptiles are pulilished by the aid of Mr. 
 Head and through the courtesy of Mr. Lind- 
 say Johnson. In this text are also included, 
 for purposes of comparison, two black-and- 
 white drawings of nianinialian 'andi. One of 
 these, the t'oininon Uedge-Hofj (Fi^. lH!) 
 
 ■ig. 143 
 
 Kiiiidiis Oculi of tlie Common Hedgehog. 
 (After Lindsay Johnson.) 
 
 reminds one of the Indian Cobra (I'late LXI), 
 while the fundus view (Fig. 144) of the \ir- 
 ginian ()pi)»uni suggests the backgminid of 
 the Iloiiied Toad (I'late l,X). In other 
 Words, th(-.e two reptilian fundi have more 
 marked allinities with other vertebrate elas.-es 
 than with Birds. On the other hand. Were it 
 not for the absent macular region and the 
 greater jjroniinence of the radiant, retinal 
 nerve lib- ■;. the ocular fundus of that noctur- 
 nal lizard, IIiiirdudi/liiH tiirciciis (Plate LIX) 
 might be regarded as an avian form, rather 
 
 closely related, for example, to the Kiwi 
 (I'late IV). 
 
 .V reference to the proliable evolutionary 
 connection between Birds and certain sub- 
 orders of Reptiles, as indicated by their 
 ophthalmosco|)ie pictures, has already been 
 made. It may eventually transpin-, as indi- 
 . d by this "straw" of evidence, that the 
 (hrkiitidir are comparatively near relati^'es 
 oi the primitive Bird, while other lacertilian 
 suborders and the Opiiidia are as far removeu 
 from them as the Marsupials. 
 
 A iletailed lescription of the three rei)tilian 
 cycgrounds, rei)resenled in the Atlas by 
 colored reproductions, now follows. 
 
 Fig. \U 
 
 Fundus 0<-uli of tlic ^ 
 (After I.iud.-' 
 
 in Oooasum 
 
 116 I 
 
 wim. 
 
TUK HKLATIONS OF HEITILIAX TO AVIAN FrXDI 
 
 117 
 
 Reptilia 
 TruKisii (iKCKo. Itcniiilncliibis liirrlni.t, 
 V.rvvi iiiijiKc; left vyr. The fiimliis .nppvar- 
 aiiccs (I'ljitc LIX) of this nocturnal lizard 
 rcniiiKJ one of the Kiwi (Plate IV). The 
 orange-red liaekjjround is uniformly (lotted 
 with dark .sp(<t.s, while the cireular papilla is 
 coi:i|>letely ohscured l)y a ehocolatc-browii 
 
 I'ij;. 1 t.-i 
 IVclpii of ii Tiirkisli Gei'lii) {Itermuladi/lu.i tun ii.i). 
 
 pecten, whose pointed free end projects a 
 medium distance into the vitreous. There 
 are no si>;ns of retinal or choroidal vessels. 
 Clearly defined, white lines (opa(|ue nerve 
 fibres) radiate from the disc margins, Riving 
 the elFeet of a halo about the central zone of 
 the picture. 
 
 A Internl view of the Gecko pecten is seen 
 in Fig. H.'i; it is .suggestive of a similar view of 
 the Aptcry.x ix'cten (Fig. i7}. 
 
 IlfUi.NKi) To.\n. I'liryiiofiomii riiriniliiiii. 
 Plate LX. I^'ft eye. Erect image. The 
 color of the fundus oculi is a dark slate, irregu- 
 larly strewn with minute, whitish dots of 
 various sizes. There i.s an ill-defined macular 
 rcijioii. 
 
 The i)ear-shaped, grayish papilla has n 
 white margin, from which short fibres of u!i- 
 c(|ual length radiate towards the periphery. 
 .\ single ce!itral (?) artery seems to originate 
 from the nervehead and with its six branches 
 — two on one side of the disc, four on the 
 other — ;* supplied mostly to the lower half 
 of the eyeground. .\bove, a small branch 
 anastomoses with a twig that runs from the 
 periphery of the field. 
 
 I.VDi.v.v CoBH.v. Xaia tripudiaii.i. I'hite 
 1>XI. Left eye. Erect image. The general 
 coloralinn of the fundus of this Snake is light 
 gray-blue, .sparsely dotted with pigmiMit of a 
 similar but deeper color. The whole back- 
 ground is regularly covered with opaque nerve 
 fibres who.se radiate disposition reminds one 
 of Merula (Plate LVII). From the button- 
 like nptlr di.ic arise three vessels, apparently 
 two arteries of small size and one (larger) 
 vein. The centre of the papilla shows the 
 reniains or the undeveloped tissues of a 
 pecten. 
 
 -^'W^, 
 
 jjr 
 

 y.r'^iiij'L^ 
 
ClIAITKU XIII 
 
 ( OI.OUKI) l)HA\VI\(;s Of TIIK 
 ()( I LI OF mi{l)S 
 
 FIXDIS 
 
 Kkkohps III iliiplicatc cxiiclly tlic piiiiiliiiKs niiiilc l>y 
 Mr. A. W. Ilfiul for this Athis Imvc Ihmmi iilli'iiilcil 
 
 l>.v (liflinillics Ihul Imvc iiriscii iliicfly fi I|i<- r,i,| 
 
 lliiit />rcm, <lii|>li('iili< f iiiirintc drljiils mid >liji(lcs 
 
 of ci.ldr uif niiiicir iiniMirliiiicc in llie iisnnl roriiis of 
 ciilor rt'iinxluclioiit were rcKiirilrd as csscnliiil in this 
 iiivosli«iil=oii. However, ll -se itnpedinients were, 
 .ifter niiiny trials and the exereisi^ of iiiiieli patience on 
 the part of the pulilislier's oHieials. final reniowd and 
 the writer now helieves that the follow plates failh- 
 fiillv represent not only the varied and Iteantifnl 
 eoloration liut the complex lissne fornialions revealed 
 l)y the ophlhahnoscope in the ocular liackijroiind of the 
 avian ami reptilian species hereirr depicted. 
 
 For the convenience of the reader a hrief description 
 of each fniidus drawing has heen placed on the pafje 
 opposite each plate, a more complete description of 
 the o|)lithalniosco|)ic appearances, as well as their 
 relations toother fundus views, hein^ fliven in (hapler.s 
 IX ami XII. 
 
 !i 
 
 1 no I 
 
RATITiE 
 Struthioniformes 
 
 N'lmw Osiiiirli. Slnilliln rdiiiilii.t. I'liitr I. 
 
 Till' ;;i-iii-riil culiir nf llii- I'Vi'^rniiMil is iliill rril. Iti'siirinklril willi 
 iJKlili'r-rril, riiiiiiil ilnls tiiiil uf»y Kriiiiiili's. TIh' luwi-r liiilf of llic 
 fiiiiiliis ;ip|M'iir> viiiirwiiiil uriiyrr ill Iniir lliciii tlir ii|)|M'r ■.rrliir".. 
 'I'liio M|)|H'aniii<'f is pmliiililv iliic li> tlir tiiiliicriiiis o|iiii|iir iirrvr- 
 tilil'i's llial i'Vli'liil rnilii iill siiii's of tlir |iii|iilhi jis a ri'iilrc iicriiss I lie 
 I'liiiiliis 111 llic |wri|ilicrv of I lie (iciiliir liii«k)jrimnil. Tin' ml colorii- 
 liiiii of till' fiiiiilils is si'i'ti to lie iiiiiri- iiilriisc liiwariN llic ii|i|irr liiill' 
 of the cyfurumnl. Tlit- optic iicr\c ciitriincc is very liroail ami oval 
 ill shape. The margins of the iicr\i' head an* very «hile ami il is 
 possilile with the mirror to see all aroiiml Ihc pecleii. The centre of 
 the liisc. iiicluiliii^; the parts near the root of the pecleii. arc slippleij 
 with miiMite lirowii pi^jiiient liots. like Mack |K'p|M'r jrraiiis. The 
 pecleii presents the ap|H'arance of a iinmlier of iliill, dark, scpia- 
 lirown tiihereles. Il iIih's not project far forward into the vilrciiiis 
 cavity, while its outlines and contour may lie disliiiffilished liotli 
 aliove and lieliiw th" disc. The |H'etiiiale margins are formed of 
 round, ovoid projections The macula is mil very strikin;; in appear- 
 ance, and takes the form of a crescentic arranjremcnl of miiinte. 
 V'ray dots. It is seen Inwards the nasal side of the disc near its 
 upper end. 
 
 Rheiformes 
 .\mkh ( AN (IsTHli II. Hfiiii itiiiirictiiiii. Plate II. 
 
 The <'oloralion of the fundus as a wliole is liiitf. nier).'in^' into iliill 
 red at the periphery. Il is stipph'd all over with iiiinille dots of a 
 li;;liler lint. 
 
 The optic disc is maile up of while ami coarse nerve luindles that 
 cxhiliil a faintly detincd, friii;,'e-like liordcr all aroiiml its mar^iiiis. 
 liadiat in;; for a distance of alioiit two disc-lireadlhs across the fundus 
 ,irc a few, dull-nray, opa(|Ue nerve filircs thai finally disap|H'ar into the 
 liackKround. 
 
 The macula is situated slijfhlly aliove and to the nasal side of 
 the optic papilla. It is somewhat ;;raycr than the siirroiindin^' 
 cye;.'niiind: aliove Howards the outer side) and liclow the fovea are 
 a few pale, liri^ht ^reen reflex lilies. 
 
 The pi'ctcn is a massive orjjan with saw -like mar^'iiis. Ihc serra- 
 tions liciii;; of a li;;hter hrown than the central liody. The lower pari 
 of the pcclcn is sonieuhal cluli-sliapeil. ;iiid comes well forward 
 toward the posterior capsule of the lens. Mctwceii Ihc projcclin;; 
 li'clli of Ihc iM'<tinate serrations may lie seen a sli^lit stippling' of 
 pif;nieiit-like lilack pepiMT grains. 
 
 l-.iii 1 
 
 •'-J. 
 
 il^t-, 
 
 ''iife iL"i-'ihMiLA'i!St>^- 
 
 V V* 
 
 -i'-'. 
 
 l£iJ i--i 
 
RATITVB 
 
 Struthioniformes 
 
 Platk I 
 
 Striilhio cdm.hiit 
 
 Rheifonnes 
 
 Platk II 
 
 Hliid amiTicana 
 
 ■->'*'"'^T^.WW-. 
 
RATITiE 
 Casuariiformes 
 
 \\ l>ri IIM \S <' \»".ii\\ Mi\ , lifiiiiriiis luiiliihili.i. I'l;ili|||. 
 The- fllVMI riilnnrl rM'^rKlllllI i- ciiMTcil uilli II liijlililr, -ilMT- 
 
 Kiiiv »li|>|ilr. ill llii' fiirin iif tin--. -.In.rl linr- uilli llirir Imi),' ii\r- 
 I'liiiliilii.' ill :i M rtir;il iljri'i'l jii;i. A« IIiim' iIiiIIiiI liii<'> .ippriMirli llir 
 iiiMriihir ri'uiiiii I liry Ihtiiiik' iiiorr iiml iniirr('iiii\i'ru;<'iil iiiilil tlirv roriii 
 n lirilliiiiil chi-lcr III III!' fiivi'ii. 'I'luir i- iii> vUililr liiu' nf ilriiiiiriii- 
 I'liii or r. tlf\ riiiu -I'lmniliiiu llii'> iircii fnnii llir m'lirrjil fiiiidiiN nrcii. 
 Tliili' illT lici \i^llll(• I'liiirniiliil \r»vU i«r ii|iiii|iir ll<r\r llliri'-. 
 
 'I'lii' i>|itir ilJM' is liiiii.' Hiiil liiiiil -•.|iii|ii'i|. uilh II ri'i|ili-li. ii|i|iiir- 
 i'iill.\- cuiiiiivrccMlrr. 1 1 i> iiiiiri.rinl.v >|>iiiiklri| t\illi iliiikir nil di.ls. 
 wliirli.iis llii'V M|i|)rii,ii'li till' iM.'iri.'ili <il Mir piipillii. lire iniirr rliiM'ly 
 liiiiki'il. Mini ]i\\v llir ii|>|H iinilK')- of ii >li.i(liiu <'ii>l nil iiliiiiil llii' 
 ililiiv i-(l;.'i- (if till' ili,c. Till' iiiiiryiii- of lli • lirrM'-liriiil :iii- di.- 
 lilK'lly white. Iiiil \\\vy Iimvc iml Ihr "tiliniii<> ' iipiMiiniiii r mtii in 
 iiiiiol iix'iiili iiiicktiriiiiiiils. 
 
 Tlir clKPCiiliilc-liniHli I hmI I 11, 111 IK 1 1 liiiijiilcr jil ils li.isc Ihiiii .il llir 
 ii|M'\. iTM'iiilili^ M coikMiiw, iU hiliinl riiMiliiiii liciiiy: ii'>l iiiiliki' ii 
 icickMiiiiili. willi iN >i\ «( TliiliniiN riillliilril nil' ill llir :ip(\. 'I'wci 
 (')'iilriil vri'iiliniiH ciiiiir well fiirwiini liiuiiril> llic Icii^. 
 
 Apterygiformes 
 
 M will. I, .\l'|■^.ll^\. .ti)l<ri/.r miiiililli. I'hilcIX. 
 
 'riif ociiliir liiickfiroiiiiil i- iiiiifornily .iiiiii;,'«'-rri|. »ciiiic\n li.il 
 iiKilllcil with l.idwii. 'I'lic lirilliiiiil. uliilc. I'uiiiKJ ilix- i- niiiiipiiihIimI 
 liy >liciil. (i|i:ii|iii' iici\c-lilirr l.i,\ri> mil ciilirrly ckvitimI liy I lie 
 fflii'-l rjilcil liiiM- of I 111' Ion;;. Iiir;;c. iiiiil coiiiiitl |M>(lrii. « Iiom> |ioiiil('il 
 (•ml iciiclio iiliiio^l III till' jells. 'I'liere iiie no >iiriis of eliiiroiijiil 
 lilooil-N'esx'U. 
 
 I 1« I 
 
RATITiE 
 
 Casuariiformes 
 
 I'l.VIK III ('(l.illitrill.i orripiliilln 
 
 Apterygiformes 
 
 Vi.vn: IV 
 
 Aplcrii.!' iiiriiifrlli 
 
 mmss!^ 
 
RATrr>E 
 
 Tiiumiformes 
 
 M\llllNKI\ 'I'lNWIlH. rd/lx/niWd/ (7((/<l(/.«. I'llllc v. 
 
 Till' liiirkuriiiiiiil rnliiriiliiiii i», in llic tiiiiiii. ii ili'i'|) univ. tlir Iiihit 
 liiilf iiiiTKiiiu into (lull oriiiiui'. Tin- wlicilc of I In- riiiiili U tnMTfil liy 
 II I'lilli'i'lidii i>f liny iliilo piirki'il cluM'lv liiui'tlirr. In llir n|i|»<r Inilf 
 i>r I lie tii'lil llicv lire Hliitc. Iinl rnini I he rruion ■>( tlir iliv uml iliiwh- 
 «iinU llii',\ iHM'iinii' ii ilnll urinurr nilniir. ( nxoiiiu llic fnnilii'* iiml 
 riinninu vrrtiiiillx mi cilliiT >ii|c of I lie |iiitiillii iiri' wmtiiI iiniiiur-ri'<l 
 I'liiiroiiliil \r«M'li, 
 
 TIh' nnirlllii iipiM irN iii i iliill-unix iiiim, willi ii lirilliiinl uliilr 
 ci'litriit s|Mil <.iirriiiiii<li'<l li.\ ii oiiiiill. iiinl n piilc-uncn. •.Ii-nikcd, 
 rrlliA riiik'. Il i« pliiinlx vi-ililr mi iIh' niiiiil -.idr nf llir imtIcii. 
 Till- iiplic IK r\r ix umiI in ■.Iiii|k' iinil tAci'pliiiniillv liroml, 
 
 'I'lir lllil-.-. iif Ilir iMM'Icn iilinix.1 riinipli'lrl,\ rovrr* llir iiplic 
 piipilLi. uhii'li i-. i|iiil)' wliih- iiinl liHiks like ii iiiiis-. of fiiiirM' iipiii|iii' 
 iiiTvi' tilirc-.. The opiic iiiiirKiii' iirr Imrdrrril with uriix piuiiicnt. 
 frmii whiili spring n few »|iiirt iiptii|iii' iiitvc tiliri'«. Tlir imtIcii i« 
 • ■liiHiiliilc lirowii. mill ill iiilililiiiM Ik ils ni.iNsixr iip|H'iiriini r i- inmli 
 "Imrli'i' lli.'in llir Miirir nrunn in nm^l nf llii- liinN i-\iiininr<|. Il i-. 
 <Ni'>y III MM- lliiil il is frinui'il mII rmiinl willi puinli'il lull... Ili.il llic 
 rcniriil pnrlimi or riiltfi' i- ■.rrralnl iinil lliiil il i-miii'i will fnrwiinl 
 liiWiiriU till- li'ii-.. 
 
 CARINATiE 
 
 UaUiformes 
 
 \' miuki.i, Ci II \-<Hiiw. <'r<ix ijliihiiKii. I'liilr \'l. 
 
 Till- i-yi'Krminil is a iliill. Iiinlrn t'l'iiy. cnvrrrd willi liny, wliito 
 dots. Tlicrr arr nn visihir rlimiiidal vrssrls. 
 
 Till' papilla appears as a ImiK o\al. wlmsr cmilral /. is dull 
 
 oraiiK'i' iniiiKli'il »illi iiiiniili'. dark-lirown ilnls. Il alsn prcsmls n 
 marginal frin«i' of wliilr. A U-w upaiiur ii<-r\r tilircs cxlciid on rilliiT 
 sidf nf llir disc arross llir fundus, liiil for a sliurl ilislanir mily. 
 
 Tlir imtIcii. iif spiral fiirin. is ciilorcd daik cliiiciilalc-lirnwn. 1 1 
 sci'iiis III la|MT ijuilc ilcciilcdiy where il jnins I he disc, and luuks 
 like Ihe riMils of a Ircc at ils dishil end, where I he riiiillcts liury llicni- 
 sclves in Ihe disc. .Iiisl aliinc Ihe disc, smue little distance In Ihe 
 nasal side nf the |M'ctcn. is a rniinil. crey. snflly mitliiied area near 
 which is seen a well iiiarked reflex nf a p;ile Miie-jjreeii Iniie. 
 
 1<4 
 
 >5«HBF?i'tirns«RnffvrA9r^!ik^; 
 
 i... t ,, 
 
 -^•:t 
 
 ff-ir;'t 
 
 ■•:iy>T^:f5i«:s- 
 
 Th\f *:>i-. 
 
Tinamiformes 
 
 I'l.MK \' 
 
 ('iiliiihn'ti'i il,(iaii.i 
 
 CARINATiG 
 
 U 
 
 r Uiformes 
 
 I'l.AlK VI 
 
 Craj' (jlohona 
 
liigm^M^m. 
 
 }9f 
 
 "^'''iim.'^K^...mi 
 
 CARINATjE 
 
 Galliforiiies 
 |{|(l -11 Tl likKV. Ciillirhin/.i Idlliiiiiii. I'liitf \'II. 
 
 Til.' lycmdiiiKl is dull. >l,i|y i-niy. iiii(lcrlyiii« luiriilx-rs itf fiiif. 
 Ii«lil-«i;i.v (li)l>. Tlic>( ,l<i|s iiic iMiifdiinly Mnllcrt'd ovi-r the fundus 
 .'Xcrpl loHjiids Ihc unsiil ,i(|,.. lien-, on .i level with tile superior 
 end of 111., optic iier\e .1111! ill the diri-etioii of the iiijieiiljir iireii. tliey 
 Jire of 11 more l>riiliMiit white, lire closel.v piicked lo^ellier. iiiid iire 
 lievoid of 11 retlex-riii^. 
 
 I-Atiiidiiii; from either side of the optic disc mid riimiiiif.' nt rijriil 
 iiiiirles to that oryiiii lire a lew. riither fine, seliiilninsliiceiil nerve 
 liliies. which arc lost towiirds the jieriphery. 
 
 The optic disc, whose iipp.'r end is shiiped like the sharp Ix.w of 
 a lioal. appears to Ix' composed of a iiiiiss of lirilliant. white. opa(|iie 
 nerve (ilires. 
 
 The pecleii. of the usual chocolate lirowii color, is massive and 
 
 ^ "Iii'l <lul>-sliapi'd. It cMeiids well forward towards liie lens 
 
 and tajxTs rapiilly as it approaches the superior end of the nerve. 
 
 llMil,i:i<i IN (^lAii.. ((iliiniir lil.-ln'oilni. I'lateVIII. 
 
 'I'he ocular l.ackjrroiind is lijiht uray sprinkled with minute 
 yiaiiillo. wlii<li H:ive it the appearance of a roliKli surface. 
 
 The o|itic iiiMVe lii'iid uivcs one the visual inipression that it is 
 foMued of Urilliaiit. white, short, <(.arse. opa(|lle tihres. Its shape is 
 
 ^ii'il- Ixiiifi loiij. and narrow, with a rather sirikiiif; resemlilance 
 
 to the project ilitr. serrated jaws of the Sword Fish. K\tendiii>; aloliK 
 each side of the optic <lisc. at riyhl aiij.'les to it, arc a few rather pale. 
 Iliili. opa(|iie nerve til'ics. 
 
 Till' pcclcii is lijihtcr hrow II in color t liaii usual, and is ver.v narrow 
 ill its junction with the papilla. On either mcIc of it are a few miniile 
 dots of l.rowii pijiiiieiit. The inferior s<'};nieiit of the |>ecleii forms a 
 corriii.Mtcil. liiilk.\ iiia>> which, however, extends well forward into 
 the \itreoiis cavity to I he postiM-ior surface of the lens. 
 
 HH] 
 
CARINA'. S 
 
 Galliformes 
 
 I'l.MK VII 
 
 Cdtlii turns liilhami 
 
 Galliformes 
 
 I'l.ATK \ III Coliiniij- liistrioiiica 
 
CARINATiE 
 Columbiformes 
 
 \Vi)M;\ \Vc>\(;\ DiiVK. I.iiii-ii.iiircid jiirdlii. I'lillclX. 
 
 Till- iiciiliir liack^'riiiniil is nl' m iiiiiroriiily firny liiil. While iluN. 
 liirlilirif; ii|> the fiiiuliis. iirc x'lillcrcil over llic crilirc fii'lcl. A IV« 
 (■li(pri)i(l,il vessels iire In Ix' seen. 
 
 'I'lie iiplie ili>e forms ii \imfi i)\.il: il ii|>|)<';ii's jis if il wen- eiiiii- 
 posecl (if ;i (((Heel ion ((f while fihres. iilld I hesc seem hiiiiched loudher 
 l(ir m1)(iiiI (die-hiilf the len;;lh of I he l>e(teii. 0|>ii(|iie nerve fihres 
 ladiide fndii the eireiimfereiice of llie piipilhi. while several oraiiiic- 
 rcd ieli((r((i(lali capillaries, iiilerspersed wilh pif;merit dots, run on 
 either side of it . 
 
 The pceten appears as an exeepi ionally hiUfi. cornijialiMl. dark- 
 lirown mass. Seen lhroii>;h the mirnpr from aliove il has I he appe.ir- 
 aiiee of a piece of larred r((pe. The siniile Tiiacniar area is seen hilhe 
 inner side of the disc and a little al)((Ve its upper end. The sheen of 
 the pale i;reen retlex Ihal pla\s alioill il when ilhiminaled liy the 
 li;;hl of the ophthalmoscope looks like watered silk. The foxca has 
 the appearance of a small ^'rcen flare. soinelhiii<; like that from a 
 hulls eye laiilern seen close al hand. 
 
 Kl lloi'KAN Wool) I'liiKoN. ('i)hiiiih(i iMiliiiiihii.s. I'l.ile \. 
 
 The lint ((f I he ((ciilar liaekfiround is pale slale-yrax . The eye- 
 Uroiliid i> eo\('red with very small, dull-while dots, so that the w hole 
 fundi I- presents a lif;liler shade of jrray I linn it otherwise wdiild. On 
 the lower half and each side of the optic disc ar" seen several oranj;e 
 col()re(l choroidal vessels, which liec((iiie more mimeroiis a^ one 
 approaches the [)eripliery. FAlendinj; al rif;ht anjjlcs to the papil- 
 lary margin are a few oiia(|iie nerve f'lires. 
 
 .\ little ahove the superior end of the ofitic iierv ■ head and 
 towards the nasal side, is a small, round, aiiparcntly somewhat de- 
 pre-scd macular area of a diill-iiray tone. From its mariiins run 
 a (l((iil)le row of tine. l>hie-j;reeii. Iraiisliicent lines which form alioiit it 
 a lirokeii or irrcuular reflex rinj;. The liird hecomes nmisiially resl- 
 le-s when the lij,'lil from the ((plithalnio.scopic mirror is focused (di 
 this |>art of the fundus. The optic disc appears of a dead white 
 color, and seems to have a frin>;e of short fihresof the same color all 
 ahout itsedjies, \[ the junction of the pecleil with the Mervc-hcad. 
 i.e., .(loiij; the central area of the latter, one sees niiiiicroiis Inown 
 pigment dots that ap|)ear like small rootlets or capillaries and tiwr 
 ,1 relicniate ap|iearance to the papilla. 
 
 The pecten itself has a dark chocolate-lirow n color and a cork- 
 screw contour; it is unnsiially lonj; and carrow. and its lower sedi- 
 ment appears to come well forward towards the lens. 
 
 I HH 
 
 
 ^^S^^^^^^^&m^. ':e-im^m^m 
 
CARINATiE 
 
 Columbiformes 
 
 Pr.vii; IX 
 
 f.ciifo.iarciii iiiciilii 
 
 Columbifonnes 
 
 Pl.ATK X 
 
 ('i)liiuiliii juihimhii.t 
 
CARINATiE 
 Columbiforiiu-s 
 
 Nil liiIlM ( I.MiWMIl I'll. Ins. (iiiiini lir/iiriil. I'lillc \l, 
 'I'lii^ riilhlii" I" uli is i,r llii' liWiy cdldr. >rrii i;i'iiiT,-ill> in |iii:ciiii> 
 
 111 hi .|o\,>. ;||hl clAlTl'li W ll ll IIIIMIlll' U llilc (|(lK, (>|| | ||i' ll|l|>c|- ,111(1 
 
 ii.i-,il -iilr ..r I III' ruiiiliis is I lie iiKi(iil,-i, ;i siniill (llill-m-:i> :irc:i siir- 
 iciilinli'il l.\ .1 -ni\ .'iiiil L;ri-cii icllr\ (.1' siiiiill liiii'~. 'I'lic iiplic .|i>c i> 
 Iciiii;. ii;inin\. In i,il --.li.iiicil ;iiii| ■.iiiiicw li;il niiiiiilc'd ,il IIh- ii|>|>i'r cikI. 
 
 Il liH.k- ;i, ll \\r\<- IMllli-r liiilliiu ;iMi| i;lilV ill llir crllll-c uilll II uliilc 
 
 'iiii .ill iiiniiiiil. \ iiclucirk (if sIiimII. Iiniwii. piLtini'iil cliil> is dis- 
 |Misii| .il.iiii; llic 'iiilic III! filliiT si(||. ,,( ihr |i|.||i'ii: Mild siiiiic i>|iMi|iii' 
 llil\c li'>ris r\lclid ;lrl pss III,- llllldlls on .ill sides i,( III!' llc|-\r. 
 
 Tlic pfclcii is 1,1 ll ,■ iisii.il d.irk cIkiiiiI.'iIi' liiil. Il is ciirkscri-u- 
 likr ill :l|p|M,ir.iiii c, lull (,ii(. , .., is nilllcl- rlllli-sli;i|H'd iind liinks Ms 
 
 ll' il vM-n- ecu, red Willi -'iiiill lunui Iiilc-s, 'I'liis sc-yiiH'iil ionics 
 
 niMi-,. |ir iiiciill\ Inruiird Inuiiids l|i,- li-ns. 
 
 RalliforiTies 
 
 ( lil -n I. ( C.I.I. r,,!',,;, rri.s;,lla. I'hilr \||. 
 
 I'll!' |.irdi.iinii;iiil ri.li.i- i.f llii' ivc:;riiunil is dull ■j.rwy . rM-r\ - 
 wlinr -|.i iiiklcl will, ininiili-. whlli- di.ls IIimI .ii-,- i r ilnuly srcn 
 
 .•|lic.\r III. sl||M|-i,,r IrrinilMl ii.ll i.r llli- o|llir llrlM' ;inil In I llr n.ls.ll 
 
 siili- ..r I III' pi'ilin. 
 
 'rill- I.. Hi; ..|ilic disi- i, u hill-, with M IVu lin\ |iiL;iiii'iil dnl s .dM.iil 
 Its in:ii-:;ins. 'I'll,. |,rilin is lii;lilir Ihiumi IIimii in llic nniji.iilx i.f 
 
 I'ii.js: il is \,\\ \.\v^f. a\\ I liidini; llic disc t'roin \icu. Miiny 
 
 "l'in|ii'' 111 i\c lil.ics nidiiilc III. Ill llic |>ii|>ill,-ir> lii-cnnifcrcncc ;ind 
 
 CVlcIld si'MTmI disc I.Ti'Mllllls .ICInss III,. Inildlls. 
 
 M 
 
 [ I till I 
 
CARINATiE 
 
 Columbiformes 
 
 I'l.vn: \l 
 
 (!iiiiiii I ii-lnriii 
 
 I'l.Aii: XII 
 
 l-'iilini cri.iltitd 
 
CARINATiE 
 Ralliformes 
 
 ll'KMix Umi.. Aniiiiiili.w ii'iidhii. I'hilc \||I. 
 Tlic <y<!;n,iin<l i- :i \.i\ |kiI<' iiriil'oi'ni i.'i;iy ^li|l|l|l'<l hIiIi (l;iik<T 
 Sr.-iv ;iiiil \\lii(r dciN. Iliii> ■i'[\'u\>i llic wlii.lc ticlil ii ;;r;iiiMliir iip|Miir- 
 iiiicc. 'I'lic li(ii-i/^c>riliilly ,,vi\\ iiiiiciihir iirrii mri Ihc riii-.iil .isiiccl 
 
 M<:ir- Ihi' ii|)|MT<iicl (if thi'dixi .iN^ CN ii i)iMki>li liiiic. Al ilxcnlrr 
 
 i- I Mii.ill |>il with .1 Ki'llli.'inl. « liil.- cciilnil <{«[. Ariiuiid I lie niiicul.ir 
 
 II ;;i(.li i> II pjilr. Ill fii-iiy r((lr\ wliicli Iom's ilsclf in llic ;;«lirr.il Ic.iic 
 
 "if III.' riiiiiliis. hill jipiMMi-s (|iiil(' >liiir|) on Ihc inner side nl' ilu' ovjil 
 niMciibr rciiiiiii. The di^(■ i^ ,1 niirriiw, wliilc ((v.il, \vli.i>f Icn^'lli i> 
 iilidiil ciiii-lliird llir licifilil .if III.' pt-clcn. A niinilx'i- ..I' .ipiii|ii.' 
 ii.i'vt' lil.r.'^ inn ii<i'i.>s Ihc l.;ick}.'r..iind iil i'ij,'lil aiinlcs In Ihc piipilhi 
 
 ■ iiiil I'ii.lc iiil.i Ihc u'ciici'ill j.'r.iy .if Ihc I' Ins. Th.' pcclcn iiii>cs 
 
 I'liMii Ihc upper purl ..f lli.' disc, sprc;id> .ml .m il liki' lli.- r.i.il .1)' n 
 III'.' Hiid H:rii.lii;illy .li>iippe;irs inl.i the piipilhiry siilisl.nui'. l-'ridii 
 lliis r.iol il l.iiii.'. slender, spinil f.irni pr.ijeels inl.i Ihc xilccoiis. It is 
 lirowii in e.il.ir. is .if niiif.irin wi.llh. l.i.iks like :i .orkscr.'W ni\,\ 
 e\liii.ls Inrw.ir.ls iin.l .mlwiir.ls iis fiir :is lli<' eye ciin s.-.'. liMikinj; ns 
 if il weiv presx'd ;ij;,iins| the l.iw.'r purl of Ihc li'iis. Tiic iinlerior 
 .'II. I .if I h.' peit.'ii 1> iniieh .hirker ill e.il.ir llniii ils p.islcri.ir li;ilf. 
 
 Sphenisciformes 
 
 Kl.M k-l.HilKP) ('m'|^:i I'i:\.,i in. Sphcni.ii-d.'i (l,iit( rxiis. I'hilc \I\'. 
 
 'I'll.' .I.iiiiiiiiinl col.ir .if Ihc fiindiis is l>ri«lil re.l sluidinf; l.i crini- 
 s.Hi. il i> slipplcd wilh ininiilc. ihirk-r.'.l tin. I .iriiiiKc d.ils. nineli like 
 trniins .(f s;ind. .Mi.ml ,1 .lisc-lciij,'lh fr.mi liic upper en. I .if the npli.- 
 
 .lise these .h.N liccmie yriiyish-wliilc: iiid I. Ihc fiiii<|;d c.ilonil i.iii 
 
 i- di^liiiclly -r:i.\' l.iwiirds Ihc upper Iniif .if Ihc cycKrnnnd. In ,'i 
 icyi.in III.' ^Miiie disl.in.i' l.iWiirds Ihc li'iiiponil iis|>ec| of |hi' liack- 
 ui-oiiiiil iii:i.\ lie x'.n :i elnslcr of piiifi.iiiil. Iiriiliiinl. uliile dots in Ihc 
 iii.i.iil.ir iircii. I'eiii.'iiiiis nse Ihc iiicliiliM^ ni.'inlirMiie \ery fre- 
 <|ii.'nl!\- when liuhl is Ihrown .m I his purl .if the cycijr.iiinil. The 
 optic .lisc .'Nliiliiis I'lijini.'l-whitc c.ljr.'s; il is hoilow.'.j out in the 
 eenlr.'. iik.' :i scwiiifj-iniiehiiic slinltlc. Hnnnini; n.r.iss this c.iii- 
 iMvily :in.! ;it rifrhl iiiii;l.'s to lh<' intir^'in .if the .lis.' .me sees .1 iiii'f;e 
 niinili.'r of ^'niy Hlircs. 
 
 'I'lic peeten lies .dolifx the cciilr.'of Ihc iicr\.'. hIi.i'c it is oi'iinue- 
 r.'il in col.ir iiikI inotlic.l with ininnle. Iir.iwn pifiin.'iil .l.ils. Tlu' 
 pi'cteii li;is t'le nsind diirk .hocihitc-lirowii shii.lc. It is of spinil 
 I'.irin. iik.' a c.irkserew hii.l .111 ils side. .\ few slcn.lcr .ipaiinc nerve 
 lilir.'- are \isil)|e on each side of an.! al rifjhl angles lo Ihc disc. 
 
 I 1,'H 
 
 v::,.'?-;'--:v^' 
 
CARINATiE 
 
 Ralliformes 
 
 I'l.AiK XIII Ariiiiiidcn li)ic(il/(i 
 
 Spheniscifonnes Pi.vtk XIV Sphml.sru.s dnmrm^ 
 
CARINATiE 
 Alcifortnes 
 
 l'illl\. h'nifi rri:l,i iirclicii. I'l.ilr W. 
 
 'I'hr lyiuriiiiiiil is ml ;iiii| nilhcr iinifuriiily >li|i|ili'i; uilli -.ni.ill. 
 liiivr.l lij;li|.n-.l iiii.l .Ii,ik->,'fiiy dot- \l„,\r ||„. upprr nid uf llir 
 Kplic iliv .'iiiil Inwjirils Ihr Innponii • tr i^ :i Miiiill. khiik!. ivd mv.i 
 
 ■.iin-diiiiilcd l.v .1 palf. Iii;lil-nrjiy •llni. .I1..I vxjlh l,ri;.'lil liiir I he 
 
 iMiliT ,'irid iniiiT iii;ir«iiiN douMli'sN the iiiiiriihir iiKimi willi iU 
 niiind fr.v.M. Ili'iid iiDlici-d lliiil rml uiilv llii> twin l>iil riin,| ..f IIk' 
 iip|Mi' hair.pf Ihi' I'liridiis i^ v.tv s.iwili\c In lii.'|il. Tlic ..plii- p.ipilhi. 
 cil'I'iiii;. iLirriiH ;iiid willi :i nuiiidid iippcirvl icjiiily. Ii.» |i,\\ (Inwn jn 
 Ihi' .y.-iDiilid. h1i;|i- IIic piclcn cvlriKU urll lc.i«,ird .irid IhIhihI lljr 
 Inwir iii:iii;iii nf tin- pupil. A \ i.'W ol' Ilic inmli.-.id i, rrmcli nl.- 
 sciiic <l liy I he Imdy of I In- riiiis^ivc pcclcii wliicli iilriiiiNl <-.,\iT-. il wlicii 
 xiii. ii> wilh III!' iiiiiriir. frmii mIhivc iIuwiiwm'iI. Tin- >riinll sci.'- 
 iiiciil \isililc wilh III,' iiplillinlriiiiM'op,' nppcir-. not lirilli^iiil wliil.' 
 IhiI imIIici- ;i l.liii>li-wliilc. Ilir iM;iii;iiis cif I III' pclrri ImIii;,' I'dvcrrd 
 
 willl lll.K k piiXIIM'lll. 
 
 Kvli'iiiliii;; ill i'ii;lil ;iiii.'li's In llir .Hm- on liolh sides .iii' ii frw very 
 
 tin,', yr.iy np;i,|u,' ii,'r\ ,' lilircs lli.'il liiiiilly disiippi'iir in ||||. f |;il 
 
 IM'iiplii'iy. 'I'll,' pi'cli'ii is ,.r 111,' usnni (liiM'ipliili'-liniHii i',>|,>r mikI 
 "■ ''^ "'11 I'liiUMi'd loHjirds llii' lens, (spiiiiilly in i|, inlViiui- iispcl. 
 
 Lariformes 
 
 (iliKM- Hl.M K-n\< Ki:n (Il I.I.. I.drii.y DKiriiiii.--. I'liilc \\l, 
 'rii,' p'licnil (olniMlion nf Hk' ,'\,'-.'i'niiii,| xiirics fn.in ii dull jiiiiy 
 In 11 iliill lin.un iiinsily III,' l.ili,'!- I i;i versing wliicli jirr niiiny 
 ri'ildisli i'lini'<ii,|:i| \,'ss,.|s running,' ninii' nr |,'ss in n \rrlic:d din,! i,in. 
 
 '• i^ IIk' Im'i- iind \isil.ilily nf Ihi's,' cjipill.irii's lli.il ;;i\,' ih,' i,,! 
 
 Inn,' In iin I'yi'-jjrniind csscnliiilly ixr-.iy. 
 
 Tlic nplic ilis,' is il loiii;. niiiTow ,.\iil. ({iiil,' uliilc. wilh ii ,|iiiin- 
 lily nf fill,' f;riiy lines riidiiilinj; in nil liire,! iniis frnni lli,' piipilliiry 
 iniii-yin. On tli,' inni-r :ispee| nf the ,'ye^^rniniil Hie niiiiiilii is sc'ii. 
 
 Il is siliiii|,',| ill I nil,. ,|is('-|erif;lh frniii Ihe iipp,'r ,'\lr,'niily ,)f I he 
 
 pecten iin<l liiilf 11 ,lise-|enHlh iiKnve Ihe ind nf III,' Miine <>r;;iin 
 "II Ihe inner si,].'. 'I'lie niiiciihi leseiiilili's n lilii,.-i;i',','ri (hik,' nf iri- 
 desciit cjljiss. It is nf ,,\ii| shiipe wilh ii reildisli-lirnwn c'liler. 
 which. linwevi'V. is nnprnvided wilh 11 r,'i;,'\ riii};. 
 
 The peel, 11 iippi'iiis In li,' in fnlds; ih,' |nw,'r. or hrniiiler pnri inn 
 exleiids wi'll forwiird lowiinls Ihe ji'Hs i.nd liiriis lowiirds Ihe iiiisid 
 side nf III,' liiriTs liciiil. The inner ((Uiidiiinls of (h,. fmiilns iir,' more 
 eiisily s,'en wilh Ihe ,>plilliiilriinsenp<' Ihiui ih,' nii|,.r jmir |,ii|, so fur iis 
 Ihe hiller iin'ii is visiMe. ther,' is nn si;;ii nf i, sc'on.l niiieiihi on Ihe 
 nnli'r piirl nf Ihe eyi';,'rnnnd. 
 
 ! I^+ I 
 
CARINATiE 
 
 Alciformes 
 
 Tlatk XV 
 
 Frail rriila arrllcii 
 
 Larifonnes 
 
 Plate XVI 
 
 Lan. 
 
 U.1 marinua 
 
CARINATiC 
 
 Charadriiformes 
 
 SrovK ri.iivm. tHiliriiiiHii.s.milojiii.i. I'hih'WII. 
 
 I'l .M'UiiiiiMcl i« icildisii-l.ri'HM. nillii r iliTpIv iii^'tiiriilcil iiriir 
 
 I III |«ri|iliin HMil (iivcnil hIMi iininp'-ri'il i|i>N lliiil nri' mt\ (Iriix'ly 
 
 |KM kid ..II till' ii|i|Hr linir ..f III.' f |ii». |<<'li>» III,' i(|«l',c I'litriiiK'i' 
 
 iirr iiiiiiiin.il, ilinriiiihil \r,>.|s riiiiiiiii^' piir.ill.l ulth jiiil oti <.jl|irr 
 -illr .if (111 |M|illl.i. Tllr lll;i( lilii i, mil ijinlly .l.tihr.l. || i, >iti|,i|r<l 
 llli-.M' llli- ..IIIMTinr I'Mil i.r lllr iliM' oil In I'lilKT or ll;l>.ll >i.|r. iiliij 
 nliiiiil liiill' ihr ii|>|).'iri'iil liiii-lli iif llii' iMcliii friilii llir ii|>|h'|' riiij. 
 
 Till' riiiiilii, iiiliiiiiiy is>lif.'lill.v iliirkcr in Ilir rii^inihir .irr.i, wliicli 
 is siiriiiiiiiiji-.j l.v ;i r«flc\ riii«. piili' ur.iy in mlnr. in I lie fi.rin iif 
 v«T\ iiiiniilc lines nnlijilirn; frnin iU iiiiir«in>. Tlirrr iiri', iilsn, ti few 
 r.iiliiili.iii, iifiir llir f..M;i (■rnlrjili-. Tlir p.'ipilhi i, .villi,-. n\iil in 
 sli.i|M'. frinm-l :ill ninnil willi (Iciisc l>l;i(k pimiiinl. ninl ii few «riiy, 
 iip.ii|ili' iii'iM- lilirrs iirr mtii mi lilliii- siij.. i,f j|. 'ri,,. prclin is \rr\ 
 hiix"' mill |(nijr(!s well inlo llir \il irons. || is ,,( nnnsiiiil sjuip,-. 
 nil her ii;i|io\\. Iiiil whin iN.iiiiinril rroni jilmvf looks :is if il Iniii Imtii 
 ''""i|"''' I .iMil Ikilliiiiil on liolh siilr,. »il|| il !i:iiiin\ nlci' :ilio\c. 
 
 \>ii 
 
 Gruiformes 
 
 Km. I. Illii. lilt Ins jiiliiiliis. I'liilr Will. 
 
 Till- li,i(ki,'i"nn<l is ciivcrrd wilh ji niiiss of iiiiiiiilr ilols IJuil nrc 
 !.'i;i.> in III., iipp.!' Iiiilf of 111.- fiin.liis iiriil oriiiij.'.- li.L.w. Th.- !.,«,. r 
 s.-iloi-s of III,, fiiiiiliis iir.- slippl,.,! uiili pi^rni.-nl. Cli.ir.ii.iiil v.->s.-|, 
 ill-.- iiiiiii.roiis Mini mil in nitli.r s|r,iii;|i|. v.-rli<iil liii.-s on ImiIIi si.|,-s 
 of III.- .ipli.' .lis.-, 'rii.y iir.- .lull oriiii;;.- in color. Til. fov.-;i is 
 shown l.iHiiiils I hi' iinl.rior or n.is;il hjijf . , ii, i. ;iiii| jipii.-.irs 
 
 "^ -I ' ml hill.' or . Tiil.r-liki' il.'pr.'ssion, luin, .. in c.ilor. which ii'- 
 
 ll.'cls .'I i;i'iiyi>|i ,|„'.'ii fi'..iii ils c.'nli('. \ narrow (.'i-iiy .ir.l.- ..r rcfl.'X 
 rin;; siirr.iiin.ls I his pi|. 
 
 'I'll.' oplic .lis.' hiis ils .'.'nln:! p.iilion iippiir.nlly slippl-.j wilh 
 l>rii;hl orinm.'-rc.l ilols, wliil.' ils niiir>,'in is friiiK.'.l wilh ..liirsi'. wliil.' 
 (ilir.'s. IhnI jirc iilso slinj.lcii wilh lirowii pijiiucMl .loN, ispcciiilly n.'.ir 
 I he .lUliT lior.l.'r. 
 
 'I'll.' p.'.'l.-ii is of ih,. iisiiiii. .||...p (■|i..co|iil.'-lii'own I'oior. riilhir 
 
 iiiirrow wh.-r.' il j.iiiis lli<> .jisc Iml licconiiii),' mncli llii.'k.r .iii.l n- 
 
 niiissi,.- ils il pr.ij.-cls inl.i I he vilr.-.nis lowiir.ls I he l.-ns. 
 
 I I. '11! 
 
 ^H:^^^^fSii 
 
 •■\:.~^i 
 
 1^: "^t5^>^-i'£<vi A^''^ ' '^:^'MiM 
 
CARINATiE 
 
 Charadriiformes 
 
 I'l.xih; W'll iV.ilicniiiniK urdliiinij 
 
 Gruiformes 
 
 Platk XVIII Rhinoclicliix julmliix 
 
CARINATiG 
 Gruiformes 
 
 Hll\/ll.l\\ SkkikMV. I iin,im,i rri.'iliilii. I'liili\|\. 
 ■|"lir <l<>riiiii,'iiit color of III.- riiiKJiK iMiili is » iliill .{nil.. Omt \\w 
 
 '""'■'' "("'"''■iinls of II y.Kroiin.l run nillur »lnii>;lil. (Iiill-ri-<l. 
 
 rlior.ii.liil inpilhirirs lli^it f,„|,. „„„y „, ||„.y n-iicli llir ii|>|h r l.;iir 
 i.f Ihrfi.-I.l. This ri'Kionisiilsosliol wilh a «r>'<'iii«lililMr. miishii likr 
 film, vxlii.li i»|.rol.;iliK M r.'lliTli..ii 1>\ I he ntiiiii of liylii ni.vs friHii Ihr 
 
 o|>lilliHlllln.<'o|>ir fl.irn.r. Al.ovr III.- .'ImI of III.- ,|is,. 1, , ,,||. 
 
 roiiiiil <li|.r.Nsioii. •|tiil<' rl.Mr of ,iti\ rr(l.\. To Ihi- iiiiicr or liciik 
 
 -icl.' of llir eve is t|ir cirniliir Illiiciilii. « liosr ijiiiliii'li'r is .iImiiiI IIii 
 
 liiii.'s llinl of III,, iiivily ill IIkm'IIiI of III., .lis,-. T|„-,,.|ili-,' .if lli.- 
 
 liii-u.r . ii-.-l.- is .|iiil.. ,.|,.|,r. Hill, ||„. ,.v,-,.|,|i f i, l.rjyiii ,||j,||, ,„.,.. 
 
 siiili ^is is soni.-li s s.-,ii ilioiii ||„. Iiiiinnii fov..|i. Tl,.. . ir.-iiin- 
 
 f.-nii..- of lliis .ml.' is ,|iiir|,|y .l.-tiii.-.l. .,n,\ |,„, „ |,rii;||i riii^ iiroiin.j 
 
 il .>f t'lish-llill!,' «|lil.-, T|„. ,,|,|j,. ,|j„, „|,|„.,,,., ,1, ,1 |,,„j, „||j,,, ,,^.|| 
 
 uilli irr.-«ii!iir iiMri:iiis. Tli,' l)l,-i,-k-l.roHM ,-..rrim:il. ,| p.-.-i.-i, i, 
 v.-i-y hii-i;.- iiii.l loiii;: il ,.\l.-ii.|, into lli,- vilr.-oiis .-iikI ;ili,ios| l..,i.-|i,.s 
 
 III.- Iciis uilli il, ,-liil,-s|ii,|».,| l.-rniiiiiil. \.i-y fi ,,,„,i|,. ,„.rv,. 
 
 tilircs ni.li,,!.- ;i| i-.-n:iiliir inl.-rviils from Ih.- »||,,|.- |,„|>illiiry ,-ii-<iiiii- 
 fi-rcii,-,.. 
 
 n 
 
 Ardeiformes 
 
 l-!i imi'KW \i(.irr IIkii>i\. Xi/clinirii.r ni/rlii-nni.r. I'liil.- W. 
 
 Th.- i-\.-tfi-.iiiiiil is .lull -niy IIII, I .■ov,-i-,-,l will, ymv isli-nliii,. ,|,,k. 
 Th.- ioH.T pi.rl of III.- ftiii,|ii> .-xhiliii, ;, iiiiiiil„.r of .|i|||.,-,.,| ,. i,,roi.liil 
 M-ss.-|s. i|i;,| rii 1 ill ;i \,-rli<-iil ,lir,'<tioii. 
 
 Tli.-o|ili.-.li.,- is li>ii;,' 1111,1 of iii,.,|iiiiii «i,||||, will, ImiIIi .-\li-.-iiiiii.-, 
 romi.l,-,!. lis ciilr,- is .,n,ii>;.-r,-,| hiiiI ,.,\.-r.-.l will, ininiil.-. lirowii 
 |iii;iM.iil ,l,.ls. Til,- |i,-,'|,'ii i, ,|,>,.|i |,r,,\,ii iiiiil ils oulliij,-, „,■,■ «,.)| 
 <l,-tiii,-,| III,- »li,.|,- l,-iijr||i of III,. |i,i|,i||„. |,ii„.,ir. yi-iiyi-li r,-i, Mill ions 
 '■\l.-iiil from 111.. ii|>|i..r IvM.-lliir.ls .>f lli,- opii,- .iilriiii. .-, 
 
 Till- >.,ii,-iilii is siliiiii.-,! ,|iiil,. ,-l,>s,. 1,1 iiiiii lowiir,ls ih,. ii|i|i,.r- 
 iiiisiii iis|,,-,-| of III,. iiis(-. Il is siirroiin.l.il \,\ m, oiil,.r riii}; of wliilish 
 liiKs. lowiirils wlios,. ,.,.|iir,. is ii /oiu- lliiil i-loscly r.-s.-mM,., ||„. mii-- 
 roiiiHliiiK nliiiii. Ill ils ,.xii(.| <-,.iilr,.. iiKiiiii. is ii siiiiill fov,.ii ,-oiii- 
 |ios..,| of >;riiy-\vlii(,. slriir. 
 
 ■f' '''■■'■T-, 
 
 1 1;>8 1 
 
 /-* ■ ,=3Mi"«!''Wr«3J« 
 
 II I mm 11 iiiiiiMiii iniiiiwiyiniiMiin 
 
CARINATiG 
 
 Gruiformes 
 
 I'l.MI \l\ 
 
 ' (iriiiiiiii rrixliilii 
 
 Ardeifonnes 
 
 Pl.ATK XX yi/cHniraj- nijrlin 
 
 ^r . . /.l 
 
CARINATyE 
 Ardeiformes 
 
 KlIIOI'KVN UlTIKUN. lillllllinis .■ilillllrix. riiitc \XI. 
 
 Th.' <'yc).'n.iin<l. riioslly riKiiiM-colorcl sli.i.liiiK In v.-llow. is 
 spririklr.l Willi Miijill. <lull-\vliilc <|„|.s. AIiiionI iiriinr<lijih.k i,l„,v.> 
 I he upper riid of llir opiic lu-rvc <'iitrim(<- iiiiil l.wir.ls tin' ii;isiil 
 si.lr .)f tlu' .lis,- is llic iimciilar iircji. Tlic fiiiidal <l..ls iil lliis point 
 lire iniicli .liillcr in li.iif inul incline I, .wards a iliill luitf (•..l..r. The 
 rejiion of llie macula, enclos.',! I.-- two <ircles. cine within the .illier. 
 is also chara<lerizc.l l.y Ih.' pr< sene<- ..f v.-ry short. I.rijrht. hluish- 
 Kreeii lini's radialiiifi from the centre of the fovea. 
 
 The optic (jis<' is ovoi.l. Iihuit at its up|)er extr.'Uiily. and app<'ars 
 as if its loMKcr margins descrilie a series of small curves correspond- 
 wvj. lo the folds of the peclen. The disc on either side of the root of 
 the peel en is dull-hrown; near l.y are small, oratig'e-ri'd choroidal 
 capillaries. The papillary marjiins are <|uite white and. in contrast 
 with the shadow cast upon the neij;hl.orinf; field l.y th<' dark pecten, 
 the dis<- slan<ls out iir sharj) contour. KxlendiuK a short dislan<e 
 ove the fundi and alioul the optic disc are a few opacjue nerve fil.rcs. 
 The iH-clen. convoluted, wit!- s<Tratcd mari;ins. and of the usual 
 cli..colale-l.rown<oh.r. extends l.ch,w the lower end of Ihc opt i<<lisc. 
 
 HoAT-HM.i.Kii Xk.iit Hkhon. Caiicromn vocliliarla. IMale X.XII. 
 The eycKrouiid is <lull-r<'<l and <<.vcred with (.range-red dots. 
 These punctate dcp..sits are intermixed (.n the upper half of the 
 fundus with snudh'r ami l.rij;liler .lots of a grayer l<.ne. (t.i the 
 l"w<r half and <.n each si.lc of th.' opti.' n.'rvi' are a few ..range-red 
 clior..i<hd vessels, that rmi in a v.rti.'al .lirecti..n. parall.l t'i. the 
 long axis ..f the .lisc. Th.' nia.ula is situated le.war.is llie misal si.lc 
 ..f th.- ii.rvc hca.l. This sensitive area is rather l.rightcr in c.h.r 
 than th.' surr..unding fi.'M. an.l several white .l..ts ar.- inchi.l.-.l in it. 
 Tins.' small d.ils. Ii..wevcr. arc notic.-al.l.' only wh.'ii th.' light ..f th.> 
 mirr..r is r.-(l.-cl.'d on the r.'gi..n in certain .lire.tions. Rather a 
 l.right. irregular an.l linear rcfh-x surr.iun.ls th.' macular r.'gion, 
 which is v.ry scnsitiv.' 1.. light. Th.'r.- is a h.ng. narrow papilla with 
 roun.h'd .■xtr.'miti.'s. It apjM'ars as if it were c..mp..s,'.l .,f sh..rt. 
 whit,' fil,r..s. surrouM.ling an orange-red centre c.v.'r.'.i with nnmit.'. 
 <lark-l.rown pigment grains that f..rm a Mctw..rk ..v.r th.' wlu.h- r<'d 
 an-a. Kxten.ling fr.ini .'a.h si.].' .,f the .lisc across the retina an- a 
 few dull-gray. opa<|iie ncr\c fil.res. 
 
 Th.' p.'.ten can I..' trace.l th.' wh.ih' h-ngth of the .lisc; it is .lark 
 l.rown in .'oloi an.l gr....ve.l spirally like a corkscrew. It .I.m's ii..t 
 appear t.) ...m.' far f..rwar<l t..war.|s th.' l.-ns, an.l its uni.m with th.' 
 n.-rx-.' hca.l can r.'a.lilv l.e Irac.-.!. 
 
 14U! 
 
CARINATiE 
 
 Ardeiformes 
 
 Platk XXI 
 
 lidUuiriix xlilliirix 
 
 Ardeiformes 
 
 1*1, \TE XXII Cniicroma corhlcaria 
 
CARINATiE 
 Ardeiformes 
 
 <;r,()s.sv Ims. Pln,mlisf„lrii„lh,.i. I'ljitc Will. 
 Tl„. „,,u.ral ,ol.,r of ll„. .-.v.-Kro,,...! i.s l.lu.-^-rav. It is ....v,.,-,..! 
 .,v a .,>a.ss of niiMut.-. ^aavisli ,|o(s. Ihnl prol.al.ly f„rnisl,..s |(,,. |,V|„ 
 I... .r. Inn.l kh.v ..,„.. .1,., a,,,K.ars wh.n ll,.. rays r,.(l..,.t,..| |,v ||,.. 
 ..|.l. l.alnu.s,.o,H. ar,. throw,. o„ ii. Tlu- i„f..rior .,Ma,lra.,ls ,',( ||„. 
 r.ni.lus. ,„,i...bMK Ix.ll. ...ar^nns of ll„. opli,- ,|j.s,.. ,.x|,il,i, ,, |,,,.,,. 
 "un. ,..r of oranK..-r...l ,.|,oroi,lal <.a|,illari..s. Tl.,.v ar,- v,tv mummt- 
 ""s Im-Iovv ||». n..rv..-l,..a.l. an.l s„tr„s.. ,|„. „.|,ol,. f„„.|„s'„.ar ll,,- 
 I«Ti|)licrv with an oraiiKr-|)iiik kIi'W. 
 
 .\|,,,ar,.iilly Ih.-rr is I.mI o,„. ,„i„Mlar ar,-a. situat.-.l al.ov,- thr .lisc 
 an.l on .ts nasal si.h.. In th,- .rntr,. of this r.-«ion is a small, whit... 
 ■•..nn, ,h,| s„rroun.l..l l.y a hrilliant l.ln,.-Kr..,-n rHh-x. Th.-r,. ar,- 
 also, iuw Mm-s ra,liatin>; from tli,- <vntr,- of th,- f,>v,-a 
 
 Th,. papilh, s,-,.ni.s to 1„. forn>,-,l of ;, mass of ,■„;„,,•. «hii,. fi|,r,.s 
 ' '•■•'■' •«■ l«a,-.-,l for al.„ut half its l,.n«lh only, th,- low,-r part U-inK 
 ...M-nr,.,l l,v t ... n.a.ssiv... .-lnl.-sha,H-,l p.-,,..,.. Th,- lall,-r or^an" 
 "f III.- ..s„al ,h,.,„lat,.-l.rown ,„h.r. proj,-<-ts w,.|| forwar,! t,.»ar,ls 
 IIh- po..l.-nor as,K-,-t of tl.,- K-ns. Tlu- ,lis,- is l.or,|,-,.,.,| ,vith l.h.,-k 
 p.Knu-nt wh„.h ,-,-s,-ml,l,.s a sl,a,l.,w ,-ast on ll„- ,-y,-Kro.,n,l. A larK- 
 >""nl„-r of s,.nn-lransln,-,-nt n,-rv.- fil,„-s oripnal,- at (h,- ,.,l„,.s of 
 
 ""■ ';"";; '"■;" "" ^"l'-^- '•^l'-"«l "<t..ss tl,.- ,h..roi.lal v.-ss,-ls a.„l 
 
 ,-v,-ntiially ,lisapiH'ar. 
 
 Vmkimcan J.'.Mim . Mi/rlrria aiiirrinni'i. I'lat,- XXIV. 
 n,,- K..n,.ral ,-oh,r of th,- f,.„,|„s is „ slatc-grav. th.- wliol,- .-v,-- 
 «n,un,l l.,-,nK ,,ni|,. nnifomiiy sprinkl,.,l with small, Imt varion'slv 
 S.Z.-.I whit,. .lots. In ,h,- npp,-r an.l nasal ,,na,lrant of tl„- pi,.|„r,; i"s 
 lli<- small. sinKi,. ma,-nla. an ar,-a ,lark,-r than th,- snrr.-nn.lin,; parts 
 wh..s,- .-xa.t ......tr,- is o,.,.npi,-,l l.y ,h,- fov,-,. I„ ,|„. h,„,,. t wo-thir,ls 
 
 "I II.,- fi,-hl an- s.-,-,. nn..u-r,...s, plainly mark,-.! ,-h..r..i.ial v.-ss.-ls that 
 -xt.-n.l th.- who!.- h-r.fitl. of th.- p,-,-t,-n. .-onn-rKinK s,m>,-what towar.ls 
 II"' |...sl.-rior asp,.,., of i,s has.-. Al.ont tw„.thir.ls of H,,- lon« an.l 
 
 ,:\'' '"■"""' '"•'•^•''•' ' '^ l''""'l.v visil.h.. ,.x,.,.p, ,h,. ,.,.,.,ral portion 
 
 whuh ,s part .V ol.s,.,.,.,.,| l.y ,|„. ,,,,„.,, This larK,.. l.ia..k-l,rown" 
 OVUM,. ,hv„l,.,| mto 1.5 lai-K,. a..,l s,.v,.ral nn«h s.nall.-r ,lonl,|,. fohls 
 '';>"in,at,.s al,ov,. in n thin, .lark r.«|. Th.. .lis,- is fiinK,',! I.v ,h.rk 
 |..«.n..r,t «ra,ns an.! fron, its lat..ral .nar^iris pr-oj,.,., . „„„;,,,, „f 
 sh,.rl. faint, whitish lin,.s. 
 
 Hi] 
 
 'm,'k 
 
 ^:^.' 
 
CARINATiE 
 
 Ardeiformes 
 
 Pi-ATK XXni I'lnjadl, faliincUun 
 
 Ardeiformes 
 
 Pl-ATK XXrV Mijrtin'a aiiir 
 
CAMNATiE 
 
 Ardeiformes 
 
 Si'dOMill.l.. I'ldhilid liiiciiriidid. I'lalc \X\". 
 
 'rill' ccpIiii- 111' till' cyrjiiiiiirKl is (Icciiii'illy ;.'rjiy, lit'ciiiniiiK lirnwiiisli 
 lii\viiril> Ihi' |irri|)li<'iy. Tlir nilirf fimiliis i> cnvcrcd willi iniiiiilc. 
 iiTfiiuliiily >li:i|«'il. uiiiy-wlillr ilols. Ili^il ii|i|HMr iiiiirc (lisliiicl iilioiil 
 llif iii;i('iihir rt'jjioii. At I lie I'ovcii. wlicri' llu'y iirc lirillitinl wliilc, 
 llicy iiir >lill iiiiiri' cloM-ly |iii('ki'il. 'I'lir fiivriil ri'f;ii)ri iippciirs lit lie 
 Miiikcii Ih'Iiiw its Mirnpuniliiii;s iiiiil u> lir riicltiscd in ii pale. ;;rci'iiisli 
 in'llcxi riiij; that is nf oval slia|M-. with its loii^ axis hori/oiital. The 
 optic disc is a liiii},'. narrow oval, and presents a lirilliant white 
 ap|M-aranec. Near its upper end arc several choroidal vessels of a 
 pale. v;"hlen-yellow color. Parallel to the loni,' axis of the ner\c- 
 hcail is another eloiiyati'd mass of white tilircs lahnosl like a second 
 optic disci having.' its centre stippled with fine pi<;nient dots, and 
 cxlcndint; across the eye;;ronnd. Hadiatinf,' from tin marj,'ins of 
 the papilla one sees a nnmher of faint, translucent titires crossinj; 
 till' small white area on the nasal side of the nerve. 
 
 The pecteii diK-s not extend very far forward: it is dark f;ray- 
 hrown and appears to l)e completely covered » ll h a nuinlier of warty 
 prill iil)erMiices. It ap|K-ars to lie attached to the whole len;,'th of the 
 centre of the disc, that is stippled with tine red dots. 
 
 Anseriformes 
 
 Hi.M K-Hi:i.i,ii;i( Tni;i: I)i ik. Ih iHlriH-iitiuti iiiitiimiiiilis. IMatc WVI. 
 
 The eye;;roinid is colored a li;rht fawn hesprinklcd with minute, 
 white dots, that jilistcTi when a strong; lijriil from the mirror is thrown 
 upon them. ( )ii each side of the papilla is seen a mimlicr of choroidal 
 \essels. Iiriirht oranf;e in color and rather strai;;ht. The disc is also 
 oran^e-rcd alon;; its imijor a\i>. this central zone hcinj; stippled all 
 over with a network of fine lilack dots. The circumfcrcnc<' of tiie 
 disc is friTimd with while tilircs. Ttie dark-lirown pectcri arises, as 
 Usual, frniii the whole lcn<;lh of tin- disc. X'icwed from ahove it 
 seems ver> thin and twisted like a corkscrew. \ few opaijue nerve 
 tilircs extend for a short dislance and at riuht an>;les to tile disc on 
 ell her side. The upper p.irl of the fundus is almost oliscured liy 
 iiuiiierous minute, lirilliant, while dots. 
 
 mi 
 
 m,..M .mA-:i \ \m ..jl" -'^jm^^Wf.^..j^,^^mm-.^ 
 
 : ifWUt iSisTJXlf: 
 
CARINATJE 
 
 Ardeiformes 
 
 PUATF. XXV 
 
 I'lafaliu Iciirorodia 
 
 Anseriformes 
 
 Platk XXVI DciKlriiri/iina aiitiiiiiiKilin 
 
 m^^n 
 
CARINATiE 
 Anseriformes 
 
 Ml. I K Sm)\\-(;i»)sk. Chni rtiriilixnns. I'liilc \\\||. 
 
 Tlir fiiiKliil <nl(ir is ii ilisliiict fiiwii. spriiiklnl with •.iiiiill. roiiiiil. 
 <iniiii;i-|iifik (li.ls iif irrcKiiliir sliiipc hikI size, liiiiiiiiriu vcrl iciillv 
 |>.isl .'iikI ixinillcl with thi- optic piipilhi. over tin- lower half of thi- 
 liiiiihis iirc iimiici'oiis. strainlil orjiiiKr-rril choroichil (■■•ipiniiiii's. 
 
 'I'hr fovi'ii is proliiiliK in<li('iit<'<l l.y ji snuill. KHsl.iiiriK white <hit 
 iil>o\c the end of the disc on the iiiisiil side. 
 
 The optic iieiv<> head is lioat-sliaped, tinted oralij."' aloiiji its 
 central zmie. and shows a narrow rim of coarse opaifne nerve fihres 
 that form a frint;e aliout its circnniference. This orange centre is 
 
 sprinkled with nnnierons minnle. dark-lirow • Mack dots. \ 
 
 few Kia.v opatpie nerve fil.res arise from tile disc margins and cross 
 the fnndns horizontallv. The peclen. of corkscrew shape, rnns the 
 whole lcnf;th of the disc and comes well into the vitreous. 
 
 Pelecaniformes 
 <'<)UMi)H\\r. l'liiihiiriHimi.r varbo. I'jnte XXVIII. 
 
 The fnndns oculi is mostly of a slate-gray color, uniformly 
 sprinkh'd with numcrons. inimile while ihits. closely pack<>d together. 
 Rnnninj; chiefly parallel with the long axis of the optic disc are 
 scver.d rather straight, iirange-red choroidal capillaries, that extend 
 the whole length of the papilla and l)cyond its inferior extremity. 
 
 The rnacniar area is se<-ii a little ahove the npp<T end of the 
 optic disc and on the na^;lll side of the nerve. The fovea appears 
 as a reth'X image of a few short, hright. white lines snrronnd<-<l l.y a 
 narrow ring. 
 
 The opti<> disc ,ip|M>ars as if it were composted of a mass of very 
 while. eotlon-lik<- lihn's, disposed as a fringe all aliont the papillary 
 margin. The central area of the disc. es|M'cially on each side <if 
 the root of the peclen is orange-re<l. stippled with nuimte. I.rown 
 pigment grains. l'er|H'ndienlar to the papillary nnirgins are a few 
 sh. rl, tine opatjue nerve fil.res. that rmr h.wards and arc finally h.sl 
 in the |H'riplieral eyegronnd. 
 
 The iM'clen is r.ither long and of the nsnal chocolate color; it is 
 innch narrower than nsnal <.n the npp.'r half of the disc, and comes 
 well forward into the vitreous linnK.r. extending liehind Ihe margin 
 of Ihe pupil. 
 
 I4.i i 
 
CARINATiE 
 
 Anseriformes 
 
 Pl.ATK \.W;i Clnii arnilfxcniK 
 
 I'l.ATK XWIII I'halarrocoriu- cirho 
 
CARINATiG 
 Pelecaniformes 
 
 (iwVKT. Sllld hllx.idlKI. I'lillc WIN. 
 
 'I'lir ;.'i'ii<Tiil I'tilor of I In- ('V<>);riHiiiil is iliill vrlliiw xvilli ii ;;rii,\' 
 liiil. I'ViTV wlicri' coMTi'd willi liulil «>■">■ 'lols, lli:il iirc iiii»l niiiiirr- 
 i>ii« (III ilif ii|)|M-r liiilf iif llif fiiiKlus, Kcliiw. iiiiil on riK'li >iil<' of 
 
 I lie oplir lU'r\r, art- scvcriil oriinjic-rrd rlioroidiil \f>.srl>. tliiil lire 
 riiirly slnii;;!)! ;iii<l run |iiiriilli'l wilii llir loii^' ii\U of llii' disc. 
 
 rill' iici'M' crili'MiKi' iitid iH'clrii nrr siliialcd I'iillii'i' liiirli up in 
 llir tit'ld: t'oiisiMinciil l\' il is t'lisv In cMiiniiit' llic details of llir |H'ri- 
 papillarv liack^roiind. 
 
 Aliovc llif iip|MT <-nd of tlic optic disc and a little towards llie 
 nasal side, is a small circniar macular ari'a. red in tone Iml surrounded 
 l>v a larv'er circle, like a n^ay shadow. The niarjlins of the latter 
 uradnallv fade into the liackKround. The visilile mar^'ins of the 
 papilla, apparently composed of coarse, while. opa(|Ue til>r<'s. arc 
 iiol. as in many s|)ecies. covered l>y the |H'clen. The central part, 
 ni'ar the root of the |M'elen. is orange-red in color. 
 
 The iK'cten itself is evidently attached to tlie disc fiu' nearly its 
 entire Iriiijlh. and it d<K's not come forward towards the lens. 
 
 .Vl vritAT.r w I'ki.KAN. I'iIiviiiiii.'< nmnpiiUldliix. Plate \XX. 
 
 The color of the eyejjronnd is a ihill liiil deep UTax. sprinkled 
 ;,'enerally with irregular dots that are most numerous in the upper 
 part of the fundus. The lower <|inidranls of the field are covered with 
 a rather faint orany-red. choroidal capillary system, disposed in a 
 \'ertical dirolion. The disc is a wide, pointed o\'al, cxhiliitiiiK a 
 mniilier of lirif;ht-red orange rid;,'es that are uiiiforml.\ stippled with 
 M.ick pifiuicnl dots. The disc mar^'ins stand out as a clear while. 
 The pecten. hroad and massive, seems to fill the pupillary area. It 
 proj<'cts far into thi' vitreous, reacliinj;. indeed, the post<'rior surface 
 of the lens. In spile of its lar^'e si/e and intraocular disposition itotli 
 the free ami the attached ends of the pe<ten can he <iullined li,v the 
 ophtlialnioscope. Passing; in a radical direction from its circurn- 
 ference is a numlier of opa<|Ui' nerve tihres. 
 
 The siii;;le macula is to lie found on the inner side of the fundus. 
 
 II is surroundetl hy a mirrow. sharply defineil. reflex rinj; of ;;reenish 
 color. 
 
 I UNI 
 
 ^Rf! 
 
CARINATJE 
 
 Pelecaniformes 
 
 Pl.AlK XXIX 
 
 .S'm/(» hanKdna 
 
 Pelecanifonnes 
 
 Platk XXX Pelecaiiu.1 conKpicillatiis 
 
CARINAT>E 
 Serpentariiformes 
 
 Sfim.lMi^ lillili. (iit/iiHii id/f lit Sir/iiiiliiriiii siriiiiiUiriii.i. 
 
 I'l \\\l. 
 
 'I'lir u'l'lirral roll II' iif I III' i',\ cui'iiiiilil j^ itllll i.'l'>i.\ . |iillril willi nil veil 
 liulit :iiii| ihii'k lii'iiwii |iiuiiii'iil uniiii* or lllll^. llir ihirkir Ih'Jii;,' iiImiiiI 
 iliilllilc llir »i/i' nf IIh' linhliT L'nilllllc^. Mixci' willi IIii'm' i|iiI> j, ,i 
 lIclIT lllii-.-. nf mi MM 1 1'. Iiriulll (HiillN I ll;ll in' it I Iii' u linlr Til In I lis. lull 
 llir,\ cull U' iilcri'vcil iIlK « lii'ii llic rflli'i-li'cl liylil nf I lir iiiiiriir i- 
 liirciwii nil llirlii. 'I'lii'-x' il('|M>«iU yivc I lii' lijirkmniiiiil llir nplM'iir- 
 iimr III' ,1 I'li'i^li >iii'f;i(i', A I hill hi.M'i' cif Iniii-liirnil iiiI'M' (iliro 
 ■•iirroiiiiiU I III' |:'i|iilLi fur it slmrl ili^lMiiri'. |iiirl iiiilnrlv nlniiu I lie Imi^ 
 :i\is 111' I lie llrrM'-ln'iiij. 
 
 A lilllr ;iliii\i' llii- ii|i|H'r rllil nl' llir ijilir iMm' ;iiiiI liiUiinU I lir 
 IIIIMll >iili' i-i \\w(illlll II III rill Is. II riillliil wllili' ilnl I'lirluvil liy II 
 
 iiiirriiw riiii; nf liriylil jirccii. On llii' Iciiiimrtil ■.iilc nl' llir ili^c. mihI 
 iiImim' IIii' i'MiI 111' il, is iiImi II liiii^r. imrriiw. »i'ri-.ilivi' iircM. Tlii^ 
 purl i» ('ii(lii»<'(l In 11 sliiliiiiicriiitf rrllrs nf ;;rri'ii liylil. 
 
 'I'Ik' nplir iHm is Iiiiik' mill rill licr iiiirriiu. Imlli iinU liciii;; riiiiiiiliil 
 III)'. Il is i|ilili' wliili' .'iinl ilri'pj.v |ii;;iiiriilril jil iN niili'r iiiiil ii|>|m r 
 liiirilcrs. 
 
 'I'lir jMclrii is 111' J liylilcr Ihuxmi iIiiiii iisiiiiI. is |iliiirily scrriiliil 
 nil I'illirr siilc iiiiil ii|i|M'iirs ;is !i iiiirriiw luiinl III l t'Xii'iiils the wliiilc 
 Im^'lli of lilt' ilisc Jiisl licfnrr its jiiiu'lioli with the nptir rirrxr- 
 hi'iiil il is slippli'il with liri«lit. nniiiiic-ri'il ^.'niins. 'I'lii' criitrtil purl 
 nf till' pi'clrli cliH's iinl prnjccl fur fnrwiiril illln llir xilrcniis; i| np- 
 |M'iirs In lie i|iiitt' niirnnv while the wlinlc IciikIIi nf ils iip|HT rilftc nr 
 crol sci'iiis nil her Wiiv\. 
 
 Accipitriformes 
 Kammkiii.kik.h. .udku \ 1 i.ri iih;. liiiiiiiihishiirhiilii.i. I'liilc X.WII. 
 
 'I'lit' ryrurc . i is sliili'-finiy iiiiil prt'si'iils i'\ cry when' :i unmiiliir 
 iippciiniiK r. ''iH' Inwi'r liiilf nf llir fiiiulils is cnM'ii'il with iliill 
 nniii:,'i'-i'i'il chnrniil.il \rssils lliiil run in ii Mrliciil ilircclinn. p;ir:illi'l 
 In till' sides nf I he nplic ilisc. 
 
 Aliiive the impilhi iilliniil Iwii ilise lireiiill lis frnlii il nn llie iijsiil 
 siilei is ;i siiimII. rniinil. (Iiirk-limwii p-^ineiileil pil, siirrniiiiiliil liy 
 Iwci ilislinelly ni.irki'd. Iirilliiinl reljex rinys. eiieh liii\iii;; n y;i'<enis|i 
 Iinl. On the niisiil side nf Ihe nerve-heiid. Iiiit nejirer llie l.iller miiiI 
 niiieh less ilislinelly niiliiiied lli.in Ihe depressinn jiisl deserilied. is 
 Ihe seeniiil niiielihir re;;inn with ils fn\eii. Il liiis :i snfl. indisliiul 
 lull diirk eeiilre. The npl ie eiilriinee is pure while with ;iii nriinjfe- 
 red eeiilr.il ,'ire:i friini which .irises Ihcpcclcii. This lindy is very 
 niiri'nw iind liipcis mi il > upper nspccl for iilmiil nnc-tiflh nf ils leii;,'lli. 
 1 1 I hen liecniiics tniieli lirniider ;ind iihnnsl envers Ihe iiiiler /nne nl' 
 Ihe disc. 
 
 I. ill 
 
CARIN TJG 
 
 Serpentariiformes I'i.\tk XWl (iitimijirtiiiiit nl Siriifiituriits •nriDiidriim 
 
 Accipitrifonnes 
 
 IVaik XWl I 
 
 (ii/IHwlK.i hartxiliiK 
 
 ^B»^^^^^^W^^i^"WfW 
 
"i 
 
 ■ 
 
 CARINATiC 
 Accipitriformei 
 
 Um.ii Km.i.k. Iliiliiiiln.1 Ii iiriHuitliiihi^. I'hili' WXIII. 
 
 'rii<'filliilll«i-> liiii>ll,\ ii ilnik ni|i|i«li-lir"»li. lllf liiwrr lijilf ilijiii.'- 
 iliU III II (lull iiriiMUf-ri'il. Till' liiHir txruniilliil ix riivirnl ^jlli 
 rliiiriiiiliil M'oiiU. iiiil io iliilli'il with liniwii iiiutiirnt ^'riiiii». uivitiu 
 it :t riiiiL'li. uiMiiiihii' ;i|i|M','iniMi')'. A k'i'iiv '•lii'i'ii |M'rvMilr> I III' ii|i|H r 
 jiiirl iif I III' fiiMilii- I In I III' lrlii|Hiriil ^iilr nliil vniii' ill-l:iiirr fniiM 
 I'll' ii|i|H'r I'liil iif Ihr iijilir ni'i'M' i'< n lirilliiiiil . uiiilr. ri>iiiii| ilnl -iir- 
 riiiiiiilt'il li\ ii oiiiiill. Ii^lil '^rt'i'ii ri'lii'X riii^', wliirli !■< JNt'lJ' inrliiNrii in 
 M lirillitiiil. iLirriiu. Kr)'!'!! iiiMi'iilitr n'^ioii. (hi llir iiiimiI oiiji- nf I lie 
 iliv. ,'itii| nil ,1 li'M'l willi lliii iii.'iriilii i> iiimlin'r iimi. of ii uriiv injiir. 
 iiirriiiliiilrij liv II f:iri->li;i|M'il. Iiiiiiiliiiiio rrflrv. 
 
 Ilii' iiplir iii'i'M' I'lil rniii'i' !■> i|i>l iiii 1 1.\ wliilr. iiiiil iilmiu il« iriilri' 
 j< si IT w II ^1 hirui' II I Ml 1 1 irr I if iiiiiiiilr iiiuiiH'iil iJiiN. Tin' ■■liter Miiir|.'iii 
 ■ if till' ilisk i-> linril^'ii'il »ilh lihuk |iii,'Miriil . ii" if ii »li.iili>\v wrrr ciisl 
 ll|)ii|i il l>v llic |M'('lrll. 
 
 \\ III 1 1 -liu.i.iKli Skv K.M.i.h.. Ililidilii.i liiiiiiiiiisfir. I'l.ili' \X\I\ . 
 Till' ciiliiriiliiiii nf I 111' ryi'trriiiiiiil is iiiii»ll\ ijiill-lirnwii. llir linvrr 
 
 i|ll;iill'.'lllls of I III' lirlil Kcill^ I'liM'rril willl illlll. iirilllp'-ri'il. rlli^l'nililll 
 IiIikhI-m-scU. Tlir liisc :- a Inn;; wliilr iiviil. hIidm' I'rlilrc i» linlnl 
 willl ■iiMimi' Illlll iiiviTi'il willl lin> piuiiii'iit iliils. 'i'lir (liipilliiry 
 iiiiir^'iii" iii'i' wliiti' linrili'i'i'il willl lihirk |ii;,'iii<'iil . 
 
 'riir iipiHT liiilf of till- fiiniliiN is ciivirrii liv ji iiiiiss nf iliill ^riix 
 <|nN. Till ri' is ,1 Hill ili'tiiuil rrlli'X liriir linlli iniiciilir. 
 
 Tin- |»rli'li is MTV 111!;.'!' :illil inlilis wi'll fnrwiiril InHjirils llii- 
 IMisliiim siirfiliT nf llir li'lls. Kiilli rxlri'liiilir- nf llir nr^iili iirr 
 rir:illv \ isiliir llimnyli llii- nplil liiilliins('n|M'. TliiTf illi' vrry npaijlir 
 iiiTvi- tiliiis In III' si'i'ii ill iiiiv pni'l ■■f llir rM'u'r'iiinii. 
 
 3??^ 
 
 :iVM 
 
CARINATA 
 
 Aocipitrifonnes 
 
 I'l.MK XXXIII lldliiii'liin liiiciM-iphiilim 
 
 Accjpitrifonnes 
 
 I'l.ATK XXXIV llclidftiis IcuciHiii.iIrr 
 
 'wr 
 
 -sMr'^; 
 
 tf^TR, t 
 
CARINAT^ 
 Accipitrifonnes 
 
 KlHOPKAN KkstUKI.. Tiilliliiinilii.i(il(iil<l(ll!lis. riiilr WW. 
 Tli<- |)riiici|i!il colonilioii of the fiiiidiis is ii liuhl In-own. or l.rowi;- 
 isli->;niy. Tlit- lower (|iiii(lriiiil.s iirc slrciikfd willi oriiri;;c-ri'.l, 
 (lioroi.liil (•M|)illiiri<-. Ili.il run in » niorr or less vcrlicnl diri'diori. 
 iUKJ iM'conic more <lisliii(l .iiid lirijilitfr red jis tlicv iiiJiiro.-icli ||i<- 
 ix-riplicrv of llic ficM. Tlii' optic disc is m loriK. while oviil. sliowinj; 
 its inarnins well licvond the piKnientcd jind frln^'ed peclen. 'I'lie 
 centr.d nrea of llie piipilla ji|)pe!irs to he hollowed ont like a e.inoe 
 and the ix-cteti does not overlap it at anv point of its circnniference. 
 as is so fre(|uenll.v the case in avian fundi. 
 
 The disc extends as far downwards towards the fnndal periphery 
 as the oliserver"s eye can reach. M its lower extremity several small 
 choroidal ca|>illari<'s can he seen. 
 
 The pecten has a rounch-d. pyramidal form, slopinj; towards the 
 centre of the disc at lioth .-nds. It is of a dull l.rown color, and 
 
 cornijfateil like a photo^rraphic camera. .Vl the j tion of pecten 
 
 and papilla are scallered numerous lirown dots, so disposed as 
 to f;ive (he former thi' appearanc<' of a weh. The upp' r part of the 
 eyejjroMnd is (piite devoid of choroidal ves-i-ls, hut is covered with 
 niimit<- white dots. The fundus is nuich clearer of the retinal shimmer 
 orretiexnoticed inmost hirds. The two macular rej.'ions are .list iuel I v 
 visil.le. The nasal macula is situated jusi ahove the upper end of lii, 
 disc an<l aliout half a 'liscdeuKtli on the iiuier or l>eak siileof the eyc- 
 ^'round. It is a dark-lirown spot with a pale area all aroinid it. Out- 
 side of Ihisrcffion and enclosinnit arc I wo dislinct. pale >;re<'n filiform 
 reth-x rinjrs. the interior rinf;s hein^' ipiite free from the white dots. 
 On the outer as|H-ct of the cycKround. ahoul one-third the leii>.'!li of 
 (he dis«- above and two-thirds to (he outer si.h- of the disc, is the leni- 
 j>oral macular renioti. .\t its centre is a lijiht. unty spot surrounde.l 
 l>y a dark hrown.irea. '.(h (lies- area-are in their turn cruircled l.y 
 a snudl. pale-nreen. reHex rinj; alx.ut (me-fourlh the diametc-r of IIk- 
 (orrespondint; circle aliout IIm- su|H-rior macula. Slender, opa.pie 
 nerve fil>res run out at riyht angles to the disc on l)otli sides. 
 
 I-ITTI.K HrsTAun. Tiiroj- tvlriix. I'hitc XXXVI. 
 
 TIk- fundal (-oloration is mosdy a warm ^ray. co\ered with small, 
 dull orauKc-red ilols. In the lower half of the fiehl anil on each siih- 
 of the optic nerve entrance is a rnunlier of choroidal vessels of a dull 
 oraiijic-red color, running' parallel with the disc. 
 
 So far as seen (he papilla is a dead white; optic fihres form a 
 frinue-like setting ahout it. The central zone of the disc is covered 
 liy a mass of miiiute. lirowii, pi^'ineiit d<-posits of irregular shape. 
 Opa<|ue nerve fihres extend at riwht angles to th<- disc on either sidi-. 
 .V little (o the temporal side, aliout oiu- disc-length from (he upper 
 
 <'"'l "f ll plii- nerve, is a small, hrown spot like a tiny hole. This 
 
 macular area is surroiuided liy a lirilliant. >;reen reflex riu^r. Th<- 
 peeten. of a ilark (-luKolale-lirown color and shaped like a corkscrew, 
 comes well forward towards the inferior horder of the lens. 
 
 I I.U I 
 
CARINATiE 
 
 Accipitrifoimes 
 
 I'l-ATK XXXV 'I'iiiiiiiiiriiliis (il(iii<l<in'ii.i 
 
 Accipitriformes Flvtk XXXVI 
 
 Tilrar tvlrnx 
 
CARINATJE 
 Strigiformes 
 
 '^A\V\^ ()\M.. Si/niiiuii iiliini. I'hilc WWII. 
 
 On till- iiiilcr ii>|H'('l of till' piipilhi iiiiil tilxml i>ri<- (lis('-l('ii};lli from 
 it on :i level willi (he upper margin of I lie |M'e<eii. is a slight (iepressiiin 
 almost ijevoid of <'lior<ii(lal vessels. Its centre is a dark red color, 
 and on the margins cf the depression and surrounding it is a liri);lit 
 circular r<'tlcx. For some distance oiilside lliis fo\eal riiif; the eye- 
 ground is seen as if one were viewini; i! Iliroujili a translucent, >;ravisii 
 mist or liazc: and I lie fundus lliiis seen jfcnerally ap|M'ars (o lie 
 jjraiinlar with a few, small choroidal vessels showing; here and there. 
 Inside the riiif,', however, the details are sirikinulv clear, and the 
 coloration l)ri),'lil red. .VImivc the macula, on the outer side of the 
 disc, is a <|iianti'y of dark pijiiiienl tieposiled lietwceii the choroidal 
 vessels, hy con last liiakiiif; the latter stand out as of a liri;;lit oran>;4' 
 color. The inner as|M'ct of the fundus a|)pears yellow: it cxhiliits 
 numerous clioroi<lal capillarii's whose yellow tint is distincliy lirinhtcr 
 near the inferior sejiment of the disc. 
 
 CoM.MON Hakn (hvi.. Sfrij- tiaiiimia. Plate XXW'III. 
 
 The general tone of the eyenroiind is dull j;ray, with l)rij;lit oraiim'- 
 red choroidal vessels distrihiiled all over the fundu'- except at lh<' 
 macular re;;ion. \i this area the tint is much ^{r.'iyer, liein^. in 
 addition, stippled with small, irregular lilotclu's of orange-red and 
 fira.v dots. The macula, also suffused with a deep ^ray reflex, is 
 situated aliove llii' iip|M'r end of the optic disc and nearly in a line 
 with the Ion;; axis of lli.il or^'an. 
 
 The papilla is loii^' and narrow with pointed ends, and appar- 
 ently made up of <'o,:rse while fi'u-e-hiindles the central portion of 
 which is covered with minute, liro, . pi^:menl grains, that have a 
 distinctly n-ticulaled ap|M-arance. Ttiese white fibres lionler the 
 nerve head all around. 
 
 The dark-lirowu, convoluted pecleii is lar^c and extends well 
 forward towards the lens. Krom liolh sides of the <• radiate a 
 few, dull-t:ray fil)rcs that stretch a short distance across the fundus 
 and I hell disa|i|>ear. 
 
 I. -Hi I 
 
 SVP^^VUTi^'^ 
 
CARINATiE 
 
 Strigiformes 
 
 Pi.atkXXXMI 
 
 Si/nilniii (iliiro 
 
 Strigiformes 
 
 Platk XXXVI It 
 
 .SVr/x H'Dintica 
 
 .ttiWRt \^_ M 
 
CARINATiE 
 Psittaciformes 
 
 <>ll\N(.K-\\ l\(,KI) I'miIKH. Clirilsolis (imtKlllKI. I'lilll- \\\IX. 
 
 Tlir iictHTiil ciilor of llir fvr>;r<mti(l is ii ilfc|) cray, liiilcil witli 
 Imtr. 'I'hr loHir scclcir iiiiil llir iMi-ipliiiMl Zdiic arc siiiriisnl willi 
 pi'ik. I hi' liink«r<>iiii(l KciuTiilly Ix-iiin pniKlu.iIrd willi iiiiiiiit<', 
 iliill-yrlldw ilols. Tlif iiiiiciiliir iircii is siliialcd lownrds llic iiiisal 
 si<lc (if Ihr <lis<'. a lilllc aliiixf the ciiil of the |M'(lrii. Il is shijlilly 
 (Ifprrsscd and enclosed witli a liriKld Iml pale jrreeti re(lex-rin>;. 
 Kxlendini; from llie eireuMiferenee of lliis eirele. slijtlilly aliovi- as 
 well a> lielow. are a few Irafislneent filires. pale );ri'en in tone: and al 
 its eenire is a dark-;;ray dot or depression, with a small, faini lialo 
 exlendinn from its upper edjje. 
 
 Tl plie nerve-liead looks as if i| were <dm|)osed of <-oarse. white. 
 
 opa«|ne tihres. which form a fringe all around the <li'eply -colored 
 peeten. The papilla is lonj; and lioat-shaped and its outlines can 
 lie traced the whole leny;tli of the peeten. Many fine, ^ray, opai|iie 
 nerve filires extend from the margin of the papilla, cross the liaek- 
 ;rrouud of the eye and are eventually lost in the fundal tissues. 
 
 The ileep lirowii [lecten. seen from aliove. has a spiral form, with 
 a ta;,' or tail-piece al the up|H'r end. A lateral view shows it to !«■ 
 plicated, like a fan. It stands well forward towards the lens. esp<'- 
 <ially its lower half. Il has a dark lirown color. 
 
 Kakai'o. Owl-l*arrot. Stringops li<ihr<ipliliis. I'lale XI,. 
 The eyc^rri.und is oran«e-red stippled all over with lijjliter orange 
 dots. The lower half of the fundus has a larjje numlier of minute 
 dark, reddish-nray depots of pijiment intermingled with lifiliter dots; 
 also, a jfreat many choroidal vessels run in a \crtical direction over 
 the field of view on either side of the optic entrance. Tlie,\- lieeoni'- 
 more minieroiis towards its lowt-r [M'riplier.v. 
 
 The nuicula is placeij, as in Owls f;<'"<Tall.\-. on the temporal side 
 of the optic papilla, aliout one dis<'-l(>iii;tli from its upper end and 
 half that distance to th<- temporal or outer asjM'et of the fundus. Il 
 is a lirif;ht orange-red area surrounded Ky dark, red-gray pigment, 
 like a shadow. There is no circular sheen around il, such as has 
 U'c'i noted alioul other avian fovea'. 
 
 The optic nervehead is whil<', jind along its centre ap|M'ars ,-i nel- 
 wi.rk of iiiinutc, l.rown pigment dots <luslering around the >ides of 
 
 I he peeten. .V feu rtliite opa<(Ue nerve filires extend a sliorl distance 
 on either side and altout the upper <'nd of the disc. 
 
 The lilaek-lirown |H'cten extends the whole length of I he disc. 
 
 II is ralher straight in its upper half Imt is more convoluted towards 
 the iow<T (lart. where it is (juiti- massive and resenddcs a corkscri w. 
 It comes Well more forwan! towards the lens, so that il more nearly 
 resenililes the same organ in the Burrowing Owl than in the I'arrot. 
 
 !3Hj 
 
 « h » 
 
 ^^ 
 
 ■W^" 
 
 ■PJPS" 
 
CARINATf 
 
 Psittaciformes 
 
 Platk XXXIX Cliri/xotix (imii'diKi 
 
 Psittaciformes 
 
 I'l.ATK XL Strhiijopn hahroptiliix 
 
 ^ 
 
CARINAT^E 
 Psittaciformes 
 
 (HiKAT Si l.l'IH H-< HKSTKII ('(KKATIM). Cllnllllll (/lllirild. 
 I'liltr XLI 
 Till' liiukKromnl is of ii fairly iiniforni. linlil. uniyisli-ldnr color, 
 spriiiklnl with iniiiiili- while <iols iiilcrsiMTscd willi iiiiiiiv less iiimitT- 
 oils Imt >oiiif\vliiit liir^tcr (lark uriiy deposits. The iiiiieiilii. ill Ihe 
 upper-inner (|ii.'iilrant. is an irreKnliirly round, lijilit hrownish area 
 whose dianielcr is half Ihe ilise length: nnil whose periphery fades 
 into Ihe surrollndin^r Kray of the fundus. The upiM'r sixth of Ihe 
 loiiK. pointed [lapilla is distinelly \isil>l<> where il is not covered l>y 
 Ihe iiKJented peeten. whose twelve douMe folds have a <'orkscrew 
 tertnination aliove. I'orlioiis of the disc liorders <an lie seen from 
 aliove Ihrou^'h the plications. e\ripl at its posterior terniiiial. where 
 the dark-hrowii mass entirely covers il. Kainl. whitish lines of 
 opa<|Ue nerve tilires extend from the margins of Ihe uppi-r half of 
 the disc a short ilislance across the cenire of the eyef;round. 
 
 Coraciiformea 
 
 L\((illlN<i KlNiiHsllKli. Diirild illija.''. I'lale \I,II. 
 
 The fundus oculi is in >;eneral of a liKJil fawu-nray color minKle<l 
 with irrenularly sha|>ed white or >;ray-while dots. exce|)t in the 
 neifjhliorhood of Ihe optic nerve where it is oran«e-red. like Ihe jil""" 
 cast on Ihe sky liy Ihe selling sun. The opiic nerve cnlranee is loii^ 
 and narrow: il is while except alonj; its central area, which is oraiifje- 
 red striped with lirown pinmenl dots. .\ larjje numlier of opa(|Ue 
 nerve filires run out on each side of tin- optic nerve and at rif,'lil angles 
 lo it. The iM'clen is very lon« and narrow and has Ihe api«arance of 
 a lirown ccnli|M'de. 
 
 The macula is very conspicuous. .Mioiit half a discdennlh from 
 the up|H-r end of the n<rve. towards the nasal side, is a small, round, 
 dark depression, surrounded hy a very narrow, hrifllil jireen riufj. 
 This circh' cnclosi's a sniaHer area that is of a darker Kray and devoid 
 of till' dots seen al other parts of the eycjrronnd. The fovea nasalis 
 always apiM'ars directly opposite the pupil; lliere is no fovea tempo- 
 ralis visilile to Ihe ophllialmosco|H'. 
 
 m] 
 
 II^^^PP 
 
 TnwrTTsr^Tvm 
 
 nRSRPVf^nMM 
 
 ^m 
 
 fmmm 
 
 mv 
 
CARINATiE 
 
 Psittarifonnes 
 
 Platk XLI 
 
 ('(uuliui {lalrrlld 
 
 Coraciifonnes 
 
 Pl-^te XLII 
 
 Dacelo giga.i 
 
 wmmmmvmmmmm 
 
 mmmmmmam^Fmnntm^mii'^mm 
 
CARINATA 
 Coraciiformes 
 
 Hl.\( K lliiUSIIII.I.. SpiiijiilohiiK ililtillil.1. I'liltf \l.lll. 
 
 Tlic principal color of the ryrnroiiii<l is <liill Kniv. iiili'rs|NTM'<l for 
 soiiir <li>liiiiir iilioiil llir optic nerve ciilriiiicc willi ii liiass of tine 
 opaijiic fil>rcs llial fXtcml alioiit a ilisc-icM(,'lli over I lie fiindiis. He- 
 voimI (lie filtres are several dull-colored choroidal capillaries llial cross 
 llie fiiiidal field in a vertical direction. Near the macular region llie 
 fnn<lus is illnniinated iiv a lirilliant yray iridescence. 
 
 The optic disc is a lon>;. while oval, that exii'nds downward and 
 a liltli' inward towards the inner or lieak side of the head. The 
 IM'cten is very larnc. the lower .se>{nienl iH-inj; carried far forward 
 liehind the iris; it presents .s<'rrated nnirKins. 
 
 The inacniar renion is ((uite <'ircMlar and is red-l)rown in color. 
 \\\ iinier circli- is dead white, wliile the foveola is represenled l>y a 
 dark-red central spot. There are two liri^lit rinjjs around the 
 macula of an iridescent, hlue-^'ri'cn color, the fundus helween the 
 two circlets iH'iiiK a \'\ii\i\ luminous ^ray. 
 
 KiiiDl'KW \i(;irr.lAH. ('(ipriiinilijiis viiropiim. Plate XLI\ . 
 
 The eyet'round apiM-ars oran^'e-red. everywhere stippled with 
 small, red and lirown patches of irregular shai«'. ScalliTcd aliout 
 are several pigmented an-as, such as one s<'i-s in the eyes of human 
 sul)jecls with disseminated clioroiditis. There are a few choroidal 
 vessels in the low<'r half of the fundus. These an- fainll\' out lined. 
 Iiut they >;ive to that part of the eye^'rouml a deciH-r red than the 
 remainder of the hackjjround. 
 
 The optic papilla is short and liroad. The atitero-poslerior view 
 with the mirror shows it as a dull. >;rayish-»\liite iiody larf;el.\' coveri d 
 with lirown pi);mcnt dots. Its mar^'ins where it is not iilis<iiied 
 ■ y the mass of the |M'cten. is miK-h linhler in (iilor. Uadialiiin I'om 
 the sides of the disc, and exIendiuH for .t short distance i.-ii .'illier 
 .ide. are a few wliile, opa(|Ue nerve filin s. whirli arc lif;l't ifr.iy ^did 
 hecome less distinct on the outer side of II. e papillii. 
 
 1IH<1 
 
CARINATiB 
 
 Coraciifonnes 
 
 Pl-vte XLIII Spn(ji)U>bii.i mlraliis 
 
 Coraciiformes 
 
 Pl.\te XLIV Capriiiiiilyii.i vurnpfus 
 
CARINATJB 
 Cuculiformet 
 
 KiKiii'KW ('iiKoo. (' lulling viinorim. I'liilr XI.\'. 
 
 'I'lir I'vcKroiinil i< (jriiy willi it •'iiir((<">lii>n "f fawn, cvcrvwlirrf 
 liopriiikli'il ttilli Kriiyi-.li-wliili' ilots. 'rowiiriN llic Iowit i|iiailriiiil<> 
 i(f llii' fiiiHlu*. in piirliculiir 111 tlii' cvlrriiiilv of llic |MM-trM, llir limk- 
 >;r(niiiil i* »ii(Tiis<-<l with ii dull pink. N'mr the ii|ilic ihtvc i>n rillicr 
 >.i<|c lire x'viTiil. pliiinly visililo. (>riin),'f-rril cliiirniiliil vrsscU. 
 
 Till' iiiaciila i» M't-ii almvc tlir iliw- tnwariN IJic na-al <iil<'. 'I'lii* 
 ari'ii. slightly ri'd in liini-. ii|>|»ciirs il)-|ir<-^<M'il Im-Iihv Ihf fuiidal siiifaci-. 
 altlioiiuli no (Icfinili- f(>\ra is \i«ililf with tin- mirror. 
 
 Till' papilla is aliniiNt niniplclcly covcrcil liy llir p<'<-lcri no Ijial 
 
 • inl.v lln> iiiitlinrs of llii' fur r can Im' si'i-n l>y llir aiiliriiir |«i>lirii>r 
 
 iii>i«>iti<iii of llif i>plitlialim>sci>|H'. Where llie papillary niarjiin i> 
 xi-ilile it shows exireiiii-ly while. 
 
 The iK'clen also exienils well iihove anil lieliiw the ilise lerniinals 
 anil projeets deeply into llie viln-ous eliiiinlHT. It ap|M'ars liy the 
 mirror lo lie a ehiH'oliile-ltniwn color. (lpai|He iier\e-til>re railialions 
 are seen In oriKinale al the disc liiiirKins. whence I hey cross I lie liack- 
 Uronnil and finally disapix-ar fnim view al or near Ihe fiiniliil 
 IK-riphery. 
 
 Piciformes 
 
 Si i.i'iii n-iiHK.vsTKK Till IAN. Hliiiiii plid.iliiM liriiKitiin. IMale XL\ I. 
 
 The eyenronnd is ilnll uriiy in color, rallier rej!iilarly s|Mitleil 
 wilh whilish-tjray dols. The optic papilla is apparently composed 
 of short, coarse, white tilires which form a sort of frinue all round its 
 mar^'iiis. .Monn each of its sides and parallel lo its lon^' dialiieter a 
 few orannc-rcd. choroidal \ essels are seen. {{adiatiiiK from the 
 papillary circiimfereni-*' an- numerous opai|iie nerve filircs that 
 extend to Ihe fiiiidal |MTipliery across Ihe eyejrronnd on all sides. 
 The iM'cteii is almost lilack-hrown in color. 
 
 .Mdive the end of Ihe optic nerve entrance and alioiit half its 
 length 111 the nasal side are three dark-lirown spots, elnslered lop-llier 
 and "Urroiinded hy a small uray reflex. 
 
 I 1«4 1 
 
 ^S^^^P^ 
 
CAIUIfATiB 
 
 Cuculifonnes 
 
 I'l.ATK XI.V 
 
 ('iinilii.1 raiiDriin 
 
 Picifonnes 
 
 Pl.\te XLN'I RhiimphttMfii.i Iwmatii.t 
 
 m 
 
 ■E7*«^ "id^M. > ^ af 'j-iii 
 
CARINATiC 
 Piciformes 
 
 (■Mv WciiilJfF.i K^ II. (iiiliinixiiiiipfiiiiilliM. I'llili' \l,\ II. 
 
 'I'lir I'liMiliiN iH'iili i'. iliill ;;rii,\ liiiliil with \flli.» iiiiil iii'iirl.\ iiiii- 
 foriiilv <'liiin.'i'<l u illi iiiiiMitc. uriiv ilnli. A I tlir siiiH'riiir Icriiiiiiiilioii 
 nf llii' ri|ilii' ili«i' {nil III!' iiii>mI '•iili'i it .1 '.iiiiill ^I'liv ili'|iri'-.<iiiii, |>iirll> 
 oil I'll Ml Mill Ilk! II ri'iilral, wrll iiiiirki'il iiiiil uli<li iiiiik' »liili' 'li'l. Willi in 
 I Ills iiri'.'i iiri' aUii m-mtiiI i;iililrii viiinw ilnU. 
 
 Till' iiiltlilifs iif llii' ii|>tir iirrvf riilr:iiii'i iirr »rll ilrtiiii'il, Miiil 
 Mil' ii-iili';il iin-ti III ilii- |iii|iillii ill iU iiiiiuii vniIIi llir iii'iliii i<. iliill 
 iir.iiiL'i' "lipplril nilli iliirk lirnvvn |iii;iiiriil. 'I'lir |iii|)illii it rriiip-ii 
 H illi iiijirM' H liilr til in ». .\ liiru"' iiilliil-.rr nf lr:ili><liirriil iiri\r lilirr> 
 niiliiili' rrnlli till' ril^r iif I III' ii|ilir iHm' nil nil >iili">; llirv IhthIiii' 
 fc'iiiilrr iiiiil rniiilrr .in IIicv ii|i|ii'niirli llir fiiiiiliil |H'ri|iliri'\ nml 
 
 lillilll.V lliMI|l|M ill'. 
 
 'I'lif |H'rli'ii. Ill' till' ii>iiiil chiM'iiliilr lirnnii rnliir. rrvi'iils si-mtmI 
 rnl'k«rri'W rniiMillllinli". Il rnliir» tti'll fiirw:iril InHiinN I III' lrll». 
 mill lirrx'llU ii lililosiM'. rll|li-'<liii|H'il ,'i|i|H'iirtltirr. 
 
 (illKATKH SlItTTKII \Vl M MH'Kl KKII. Driinllllll.l III Dl IlllriiriilHl.l llllljlir. 
 
 I'hil. XI.VIII. 
 
 Till' cnlnr iif I III' ryi'urniinii is a iliill lull ijrtiiiilr .univ. iiilri°>|M-i-M'il 
 uilli .1 liirKi' iiiiiiilirr nf siiiiill. ;;riiv iliil>. lit'lnw llir iiplii' ili->r iiiiil 
 |>rrli II lire il fru fililll. nl'illl(.'i'-riil I'linriiiilill V"'>M'U. Tile oplir iliv 
 is .'i|i|iiiri'iillv niiiilc up uf ii iii;i-.- nf lirilliiiiil. uliilr. nrrvr filirrs, 
 Mry slinri .iiiil lliiik. In llir fnriii nf niiliiitiniis frniii llir niiir^'iiis 
 nf llir piipillii luwiinU I III' riimhil iHilpiirrv iirr iiiiiiiv ^I'l.^ npiii|iir 
 lirrvr tilirrs lliiil iip[M'iii' In niriipN ,1 philir liiwrr lllilli llli' ullilr rlr- 
 iiiriils nf Ilii' ilisr. Till' |h'i|.'Ii Ii.is Ihrri- I'lirksrrrw I'liiivnliilinns nil 
 till- ilisr. wliili' iN Ihwit p^irl rnriiis ;i rlllli->li,ipi'il lii:i» nf ,'| ilri'p 
 iliiM'nliilr-lirnHII rnlnr lliJil iiplH'iir> Ini-niiir wril fnl'W:iI'il InWiinls I 111' 
 li'lis. 
 
 Tlwrr M'riiis In Iw niily niir sinsilivc ii'iilriil iirrii. This >in).'li' 
 nnirlilii i> nil (III- liiiMiil siiii' nf llir pi'ili'ii iiliii Inis Ijii- ap|M'Ml'iilii i- nf ii 
 lirilliaiil. wliili'. rniiiiil ilnl. llir fillliiils Mirrnllllilili^ il iH'ili): a lilllr 
 ilarkrr lliiin llir tfrliiTal rnlnr nf tlir ryi'iJiiMinil. Tlir >iirrniiiiilin^' 
 L'ray ari'ii iiiakr- llir wliili' fiAi'a -..'anil «rll fnrwaril alinn-l as if il 
 wrrr arliially sihialril in llir vilri'inis. No rclli'X riii)i ran lir mtii 
 ariiiiiiil il. 
 
 Hlli I 
 
 'naemwft 
 
 «SPB^59«a»B" 
 
 ^■P-«W 
 
CARINATJB 
 
 Piciformes 
 
 I'l.Mt: XI, Nil ('niliirii.i iiriii>!i(iiiili. 
 
 Piciformes i'l.vrr, XIA'III Dri/ohalr.i irl DfiidriH'oiniK major 
 
 jiWBSP 
 
 ^^m^^mm^^s^m^^f^K^^^i^m 
 
CARINATiE 
 
 Passeriformes. .1. >U>nMM>i»i. Tjininiililir. 
 
 |)i;i(H\ 'l"\i(\\T. I'ltiiidiiit (lirhiiinii.i. I'ljitr XMX. 
 
 Till- I'M lmmpuikI is Iduc-nriiv. cM't-vwlicrc >|irinkli'il willi iiiiiiiilc, 
 Kl;i\ <li>ls. 'riicsi- <Iu|n tire xi closely piifkcd on llif upiHr liiilf of llic 
 fiuidiis I lull llu'v '.'i\(' il .1 ilisliii(( siKciy iipiH-iiniiicc. Uiiiiiiiiif; 
 
 ill liuhl tiufiU- lo lillicr >i<l<- of I lie opiic pjipillii iirf iirrons diiM- 
 
 wliilr opiHUlc ri'TM- filirc^: lliry cxlciul well iicross (lie cycjrroiiilil. 
 Al liiilil iiMulcs lo I he opiic ilix- low.iriU I lie iiiisii! sine Mliil .1 lilllr 
 
 ,ilio\c ils >iiprrior fii<l is :i ilciisc. pMlc-liliif. ) Iiilf mass lliiil 
 
 iippiMis lo Mirrouiid llic I'ovfji. A linlil l>lii<- redcx riiis nlso 
 riicirrlcs llii> iiri'ii. 
 
 Thi' opiic iicrvc-rriliiiiK'c is loiij;. narrow am! wliitc. lis ccnlri' 
 i> stippled Willi a few lirown pi^nicnl ilols and il is liordcrcd all 
 ai'iiiml willi -.ymmrlriiallv placed Idack pifimenl v'raniiles. 'I'liis 
 pifimeiited mar>;in \aries a lilllc in individuals. 'I'lie Ma.'k-lirown 
 |M-clen. Ions; and narrow, exli'iids wfll licliind I lie ed>;e of llic pupil 
 Ml llial a porlion of il cannol Im' sci'U lliroiiu;li llie mirror. The upper 
 pari is vrralcd !>iil llic lower half is more of I he corkscrew l,\ |>«'. 
 
 Passeriformes. />'. .\rnvi>\ioi)i. IliriiiKliiiidn . 
 
 Kl HiifKAN (lllMNK^ SwM.l.oW. II Initidn rii.ifiid. riale L. 
 
 The s;eneral color of I he eyi>«roiind is warm Kray. linled >li«hlly 
 , P \(llow or liiilf. and covcrcil willi miniili-. didl. yellowish dol>. 
 Sivr.il pale orange iclioroidali vessels arc sci'ii near llic iip|MT c\- 
 Iremily of the opiic iicrve-enlraiKc. There are \ isilile Iwd maii-lar 
 
 (•(.(rioiis n each siile of and alx.vc llie npiMT end of the disc. 
 
 They show as Miiall lirown areas or dol> in llii c\ej,'ronnd Siir- 
 roundin;,' lln' tenipor.d nia<nla is a s|if;lit rellcx. a|ipareiill.\ com- 
 posed of inimile. liri«lil yray dols. The macula on llu' ii;;sal si.h- 
 is (|iiilc dcMiid of I his rellex-rim;. 
 
 The opiic papilla, loim and narrow. Ia|«rs al its upper end. On 
 .ilher sill.' of the disc, iiid al rij^'lil aii;.des to il ,ire a few, fin.', o.iii- 
 ^;ra> opaque ner\ f-HI'ii s. 
 
 'I'lie ehocolali-lirouh. convoluted pecleii is i|iiile narrow .il its 
 iiiiietion with llic opiie nerxi'. liilt il i,'iadiiali.v liceonics wiiler and 
 more mas ;\(' ..s it appro.e lies the leiis. 
 
 1(W I 
 
 m 
 
CARINAT^ 
 
 Passeriformes 
 
 I'l.ATK XLIX I'Hiiiiiiii.i (lirhiaiiiin 
 
 Passeriformes 
 
 I'l-ATK, L 
 
 lliniiidii riiKlicd 
 
 HfHWffiffi^m^^^M^Hf 
 
 r.w>i -Vns'^ i'^;' 
 
CARINATiE 
 
 Passeriformes. II. Tiirdiihr. 
 
 Hi. I iiiiui). sidlla xiiilis, I'liili- LI. 
 
 Tlic jjciicnil liliit'-j.'r,iy cDlorin;; of I he rycjfroiinil is iiiiidifii'd \>y 
 iiiiinrroiis. iiiii-piiinl il(il>. Tlic piinctiilc il<-|«>sit> iicjir tin- |>fri|ili<Tv 
 iissiiirir 11 iriiiri' or less diill-Koldt'ii or oniii^r tiiil, ii coiidilioli also 
 noliird just Ix'low the |H'ctcti. Tilt' cloiiKiitcd. ovoid optic- dis<' is 
 xvliilc Kniilc woolly iit its iiiiirKiiis) jiiid coMTfil jilinosi entirely with 
 the voi.ivoliited |>i-eleii. wliicli is \eiy liir;,'e when eoiiipnred with the 
 si/e of I he eye. Il is of the usual diill-l)rowii color and has " frilleil '" 
 Itorders. On the inner or nasal si<le and near the lower part of the 
 optic disc is an oraiine-red area, containing chiefly choroidal vosels 
 with Mack pigment grains lietweeii IIk-iii. This red area extends 
 a little to the letnporal side of tli<' disc. sulise(|ueiitly iiicrjiiiif; into 
 the dull orange color lielow. On <>ither side of the disc and radialin^ 
 from it. are niiineroiis filiform nerve rilires whicii cross the l(ack;,'roiind 
 ainiosi to its |M'riplicry. In an area a disc-leiifjth to the nasal side 
 of the pa|)illa the white dots of the fiindns are dcciiledly fainter anil 
 much closer to^lether than elsewhere: in this rej;ioii. also, there is a 
 rellex plaiiil.v marked. 
 
 ■-■y; 
 
 WllKVTKXH. S(i.rit(>l<i irnaiitlir. Plate l-II, 
 
 The fiindal coloration is pale j,'!"'!.^'- with a dense mass of jfrayish 
 while dots |><-riiieatin<; the eiitiri- liack^'roui>d. .'^liKhlly aliove the 
 upper lermination of the optic nerve, and towards the nasal side of 
 the |M-cteii. is a well-defined, round, whitish macular region, much 
 larger than the small spots lli.it covei the whole of the surrounding', 
 duller eycitround. This white area is i' • losed l)y a lirilli.int. Iilnish- 
 f;reen circle, whicli ap|H'ars more prominent and iriilescenl in nature 
 than is depicted in the draw in;;. The optic papilla is .ilmosi entirely 
 oliscnred l(y the peeteii; il is Ion;; .ind narrow, with an irre;;ul.ir 
 outline. 
 
 On the nasal side of the nerve-head are a few short. oran;;e-rcd. 
 choroiilal vi'Ssi-ls with a few dots of j)i;;menl lik<' pepper ;;i;m?is 
 sprinkled liet ween them. Kslendin;; fnim Ixilh niar;;ins of I he opi ie 
 disc across Ihe fundus to the i«'ripliery. are numerous line, opaque 
 nerve filires. the upper omc> on Ihe nasal side I teriiiiiiatiny at the 
 macular area. 
 
 The |)ecten. red-hrow II ill color, loll;; anil narrow, appiars to 
 lie Iwi-ted on ilvlf like a rope or a eiirkscrew. Its inferior end 
 extends lieyond that part of Ihe e.M'Kroiind shiiwii in the piiluiv. Iiiit 
 it prolialily comes well fiirwiird towards Ihe posterior surface of the 
 lens. 
 
 I I"" I 
 
 
CARINATiE 
 
 Passeriformes 
 
 rL.\TK 1.1 
 
 Sidii'' .ilc'i.i 
 
 Passeriformes 
 
 Platk LII 
 
 Saxinild iriiiDilhi' 
 
CARINAT>E 
 
 Passeriformes. /> triniiill'iltr. 
 
 llursK S:'\HH()W. I'li.isrr il'umnitiviit. P1iil<' Llll. 
 
 Tlir i,'('ii('riil cnlor of I lie fiiiiiiu^ i> [Mitt-iiray lovcri'd willi very 
 filii- while dills. clD-icIv |)iirl«-il Ih^cMIht ill I In- miiciiliir ;irfii. Tlii'V 
 fiirm ii liylilcr /.one a lilllc atiovc Ilii- ii|i(«m rxlrriiiilv of llu- ihtIcii 
 anil lowaiils llii' nasal siilc iif I he iIi-m-. Krimi the <ircninf<'rfiiri' uf 
 I lie opiir ilisc a hiiiif ininilicr of railicr lonu. opai|iif \\vr\r filtrcs 
 run in railial fashion lowani- I In- (MTipiirn of I In liindiis. 'I"h«' 
 papilla appi-ar>. whrii visililr. I" In- (■<)ni|M-.^<Ml of irrcfinhirly slia|M-<l. 
 Iirilliani while Ixinilles: il can liarelv lie imllini'il willi I he mirror 
 except al the iip|«T (ami narrow end of I he iiecleii. The p<'<'leh 
 has a deep red-lirown color, and its free exlreiiiily is lull};, narrow 
 and of the corUserew l.\ pe. The lower se;;nicnl of I lie orjjaM extends 
 \.ell forward towards I he lens and. Iiciliir larile and massive, coiii- 
 pletely cover* the pupil and makes il impossilile to olilain a lateral 
 view . 
 
 \ vliiKi) Hi VTlMi. ('i/iiniixjiizti nr.siii)li)r. I'latc I.I\'. 
 
 The ii/niniiiiiil i^ dnll anty shaded to Imt)' and licsprinkled with 
 vcr.v mimile. i.'ra.\ ish-while ilol>, 'I'hesedols coalesce at the macula, 
 where they form a soft, round .irea liordcrcd liy a linlil reflex. The 
 siiiftlc macular reirioii and fovea are situated a little ali.ive the np|M-r 
 end of the pecteii and towards the nasal siile of tile optic nerve. 
 The |>ecteii. M'ry lar^re and niassi\e for the si/e of the eye. is of the 
 usual choeolale-lirown colour: il i* more or less clnli-shaped. ami 
 extends well forward lowariK the leiis. Where the peeleii joins the 
 rclin.i il is ver\ irrciinlar in -liapc. The peileii. whose onlline is 
 i|iiilc irrcyiilar. <-o\ers the papilla enlirely *o that it ap|M'ars to 
 spriiii; ilireell> from the retina willioiit ^howiiiy; the white dis<' mar- 
 ;,'iii. I'Voni the *ides of the apparent root of the pectcn a few, 
 whitish. opai|in- ncr\e lilires cros* I he field of \iew. 
 
 17.il 
 
CARINATiE 
 
 Passeriformes 
 
 I'l.ATK LI 1 1 
 
 I'dsxcr (loiHi'xhni!' 
 
 Passeriformes 
 
 Pl-ATK LIV Ci/aiKLiplzii irrslcitliir 
 
CARINATiE 
 Passeriformes. />'. I'linidiicidd . 
 
 I.WV Kllll) <il l'\IIVIH>F.. I'liniliii liiirii. I'liilr I.\'. 
 
 rin- i\ci,'r(iMiiil is \<>llii\vis|i-i;ni,\ iiv klijiki rolnr. iiiiil'iiniilv lovri-fd 
 with :i (liMsr iiiiiss i.r liiilllllc while iliilo. lluil iirc >llliill<T Mliil diliMT 
 :il lli<- iii:iiul;ir rruicpii. A few iliill-riMl cliiiii iiliil (MlMll.irirs .iic 
 visililf ciri till' liiwrr |)iiil iif till' fiiiiilu-. uriir llir ii<Ti|)licrv. Tlir 
 oplic iirr\r lifiiil. iliill wliilr, liiiif; mill iiiirrow. Iiii> ,1 riiiiriilnl ii|>|mt 
 riiil. In I'lilirc iTiilnil :iir;i ii|)|HMr> ii> if il wrvr .-i iiijiss iif line, 
 liniwii piu'iiiriit liiil-.. 'I'lir |«Tlrii i-. cxci'iiliiiiitilly liiiiu, riillicr tiiir- 
 liiw. Npirjilly :iir.iiii;cil ;iiii| cxlcriil-. liryiiiiil llir ijiiiu'i' ■>!' \isioii 
 lliriiiii,'li Ihc iiiiilJLili'il |iii|>il. 
 
 Ti) Ihr liJiMil «iilc iillil J lilllc tiliiAC Ihr I'liil iif Ihi' (Hm- j, [\„- 
 iii.iiiii.ii- ici;i((ii. ;i iliill-liiiiwii cnilci-likc ilcpriN^inii IhiiiihIimI liy ,i 
 xvliilc iiiiis> <>r ri'lliM Nlii;iliiiii>. <>|)iii|iic inT\i' lilivo r.iilijilc Irdin 
 liotli sidcN nf llii- ilJM- lull tiiiiiil.\ liisjippriir m-. IIkv ;i|i|iri>;ii Ii Ihr 
 lnMiiid.irics of I III- fiinilii-.. 
 
 II. I'liniilii. 
 \\\.\ i .l^^. t iiiiiiiirltlii rrisliilii. I'hilr l,\l. 
 
 Tlir i;i'iiri;il ciiicir iif llic rycirnpiiiid i> :i shilc-uniy, with :i p;ilr- 
 ,\i-lli>H liiil ill tin- linMT liiilr of till' rvcfiroiind. The ciiliic fiild is 
 Ipi'spiiiikird willi iri-ci:ill;ir!y sliii|HMl. Iij;lil-;;niy dots, niviiiy il l|i<- 
 iipjMMiMiKc of H roiiiili iiiid ml her coiii-sr siii-f.-icc. cspcciiillv iiriir the 
 
 riiiiciikir :iio;i wlicic llir dol> :iii- i •,• cIom'In- piickcd in llii' sliiipc 
 
 of » liiifilil. circiihir p.ilcli. 
 
 'riif oplic iiiTM'-lniid is (|iiilr while iiliil of oliloiiK sliiipc. SiviTiil 
 oniiif;i'-<cilorcil. ( hoioiihil <;ipill,iri<'s jirr vi>il>lc in lliis icj;iiiii. Ih.ii is 
 rovcrrd willi iiiiiiiili'. lnowii. piijiiiciil dols. like likick pepper i.'i;iiiis. 
 Kxleiidiiii; from ciich side of | he opi ie di>e i> n kirire iiiiiiilier of 
 opii<|iie nerve filires Ih^il evieiid across the fiiiidiil field. 
 
 The peeleii. of I lie iisii.il <lio(ol;ile-lirow ii <-olor. is r.ilher ineiiiihir 
 ill shiipe III ils >ii|)erior evlieiiiily. From .■il)o\e downward il look> 
 like ,1 ship's liirred i;ilile. Iiei oiiiiii^' hiriier ,is il ^ippioiielies il, iiiiioii 
 willi the pMpillii. The superior eiiil iippeMr, to eome wc II into Ihe 
 vilreoiis e,i\il\ nnd lo re:ieli llii> leiis. 
 
 174 i 
 
CARINATiE 
 
 Passeriformes 
 
 I'ariiliii liiiri 
 
 Passerifonnes 
 
 I'l.ATK lA'I ('!/iitit>iilta crixlala 
 
 il 
 
CARINATiE 
 
 Passeriformes. /'. Coniilir. 
 
 <(1MMII\ HlllTI>«ll Hl.MKHIKII. Tlirilllx iinriild. riiili- lAII. 
 
 Till' KciuTiil liiil of IIk- f,v<'Kriiiiiiil is ii sIhI,v-k'"''\ «""" " imifoiiii 
 ■ipriiikliiiK <>f tinv. wliili- ilol;.. Tliiri- is iii> visil»li- iiiiiniliir n-Kiim, 
 
 lull III!' whoji' f ills is covrrfd anil ils colnriiiK (.'rciillv iiii>ilifii-il li.v 
 
 iiiiiiK-rniis liiii'iir iipiKiiii- Kliri's lliiil iirisi- frniii llii' liisi- iiiiirt.'ins 
 lliri>ii({lii>ul iiiiil niiimniss llir i-iilin- fuiiiliis In llii- i-xlrriiu- |)iri|)li<TV. 
 A fi'W. fiiiiil. yi'llinv-n-il rlmroiilul vi-ssils iirr si-i-ii iiii rillii-r siilr of 
 
 iinil imriillrl li« lli<- i IitiiIi-Iv Ii>ii»; anil luirruw |ia|>illa. Tlif u|>|Mr 
 
 l\Mi-lliiril> i>f I Ik- ilisr is aliiiill lialf riiviTi-ii liv llir rliil>-sliii|M<l 
 IM'clrli, w hirli is iiiiiiiiosimI of viTV fi'W fiilils. Tin- liiassivi-. iliocKlalr- 
 coliiri'il. |Mislrriiir riiil nf llir |mtIi'Ii mlirriv olisniri-s tlic liiwrr lliird 
 i.f ll:c ilisc, whilr llir iippiT half i>f I In' foriniT lias a Iiiiil lirowii liiar- 
 
 ;;i iu nasal ns|M'rl. anil sciins In lie only in pari allailinl In llir 
 
 III I". I'-lii-ail l>rii<-alli il. 
 
 Hv\K\. <'orrii.i ninu. I'lali' lA'l II. 
 
 Till- ••vitironnil is a li^lil fawn sprinklcil willi ilols al I llin-r 
 
 >lia(lrs ilarkiT limn lliv (.'niiinil loliir. Mixcil willi Ilii- ilark ilnis an- 
 a ihiiiiImt i)f wliili- oin-s. scni i's|M'(ially wlit-ii a slnin^; li^lil is llinnvii 
 iipiMi the fiinilns. Aliiml llinr (lisc-l.miilllis fri.iii llii- iipiMr i-iiil 
 I.f Ihc ilisc on llir iniiiT siilc is a wrll niarkcil. l.riKliI ri-Hrx of a «rrcii- 
 ish-liliii' liiiKc. Il is irri-j;nlarly oval in slia|H- anil sciMiis lo U- luiii- 
 posi'il of a iiUMilM'r of VITV fine fitm-s. In llic ci'iilrr of llir ri-tlix is 
 Ilii- inaiiila. a small, ilark. craliT-likt- lii-pri'ssioii, lirown in inlor. 
 Till' liisi- is ihalky while, anil K'ivcs oni- I hi- iiiiprrssion llial il is 
 loniposid of many opai|ui' ihtvi- filiri's parki-ii ilosi'ly Iohi'IIkt. 
 Krom I Ik- ilisi- margins lln-rr railiali- a iiiimlMT of fiiii' opiic iutvi- 
 Kliri-s Ihal t'xli'iiil across llii- i'yi').'ronnil. In llu- Iowit pari of llii- 
 fiinilus.assiHiali-ilwilh a iiumlMTof oraiifXi'-rnl ih.ls.ari'a ffw oran>,'r- 
 ri-il choroiilal l.h>oil-vi-s,.i. .i-vi-ral of tin- lalliT Uv'mn ili>lril)uliil 
 alolin i-illirr si.ii" of '.li.' -Iim TIii' |m-(I«-ii is very lliin anil narrow 
 al the ilisi' liul as^iliiicsa i liili-shapc as il approarhrs lln'h-iis. wliiTi- 
 il i^ ilarkrr in roloi. Il coiiii's wi'll forwaril ami appears al limes 
 lo press a^iii'isl llie posterior capsule of llie lens. 
 
 1761 
 
 ■•^r.T&'arvBSB^wj, 
 
CARINATJE 
 
 Passeriformes 
 
 I'l.ATF, LVI! 
 
 Tiirtliis iiiiriila 
 
 Passeriformes 
 
 1'I.ATK LYIIl 
 
 I'orniH corux 
 
 .■i:\i&<i^£L i 
 
 s»5n«n»B*««w:«i»ianiifwr iV"«eica«CTr«r.'»ynisf' ■-, tiwi/s'*''^ 
 
 yjimuKujevmatfS* vivxKisim 
 
< OLOUKI) DH.WMMIS OK TIIF FlNDl S (Ml 1,1 OK 
 KKITII.KS, 
 
 REPTILIA 
 
 Tl HK1»M (iK( Ko. Ill iiiiiliicll/liix liiri'irii.1. I'liili- LIX. 
 
 Till' iii'iiiiKi'-riMl ruiiiliis i> uiiiriirinly tli>ttcil witli ihirk >|hi|.h, 
 while lln- circiiliir |>j|>illii In coinplftrlv olisciirt-il Ity IIh- cliiM'tiliili-- 
 lirnuii ihtIcii, uIiiim' iHiiiilfil free rail priiji-cts ii iiM'iliiiiii (liMliiiicc 
 into llu- vilri'iiiiM. C'Iriirly ilrfiiiril, white hiieiir iiiediilhiteil iierve- 
 filire- rniliiile friiiii the ilise iiiiir);iiis. )>i\ iiit; the etfeet ofii lialii iihoiit 
 the iTfilral /i>iie of the piitiiri'. 
 
 lliiKNKK ToAii. I'liri/iiimiiiitii iiirniitiim. I'late I,\. 
 
 The general eoloraliiiii of I lie eyeuroiiiKJ is a ilurk .tlate. irre^^u- 
 larly strewn with iiiiiiiile. wliitiNli clots of various sizes. There is 
 Mil ill-ilefiiieil iiiaciilar re^jioti. The |H'ar-slia|M-<l, );rayisli papilla 
 has a white iiiar^'iii, from which sho.t tilires of iiiie' 'lal leii);lli radiate 
 lowarils tin- iH-ripiiery. A siiif;ii -itral ( i"! arler- 'ems to originate 
 from (he iiei ve-liea<l anil with its six liraliehes iwi> on one side if 
 the disc, four on the other is supplied mostly In the low<-r half of 
 the tield. A small liraiieh anastomoses aliove with a twi^ that runs 
 from the |M'riphery of the fundus. 
 
 117HI 
 
 ftA.-^'ifti 'BMBBfVfrr 
 
 *!)■ 
 
 "Tsw'Fr-^frTTrwr'asKT^aiffT' 
 
REPTILIA 
 
 Turkish Gecko 
 
 Platk I. IX IIniii<liirt!/lii* tiirrlciix 
 
 Horned Toad 
 
 Plate LX Phrynomma cornutnm 
 
 ^S5^SS5Bs?^^^^^^^^^^^^5?v? 
 
 Ai..i.\\_. 
 
 m/mim 
 
REPTILIA 
 
 l\IH\S < i>llll\. Xiliil Irlliilililllli. I'lillr l/\l. 
 
 Till' p'Iii'imI ciiliinitliiii iif till' fiiiiilii^ iinili in llii-> Sn^ikr i-. li^lit 
 (jnix -liliic. s|)iirM'lv iliilli'il vvilli |(i;jiiii'iii nf ;i >iiiiihir' l)iil <lrf|it'r <iil(ir. 
 Tlic wliiilr liiK'kKriiiiiHl i>. ri'Kiiliirlv <ii\ crrd willi i>|>ii<|iii- iinvc 
 Hliii'>. I'liiiii till' liiilloii-liki' iiplic (IIm- iiii-f llirrc \rs>cl«. ii|i|>iif- 
 I'lillv lull :irlrri<"< nf <liliill "i/r iiiiil iilir liirurr \i--><<rl |iriiliiililv ji 
 vriii. Tlir (fill rn if tlir |iii|iillii nIihw- I lie ntiiiiili-. iir I lir iiMil('\i'lii|>ril 
 llNMlri iif a |M'('li'li. 
 
 Iwi 
 
RBPTILU 
 
 Indian Cobra 
 
 I'LATK lAI 
 
 Xai'a Iri i>uditiii.i