500 BOVGHTON,Notes on Arian Coccidiosi• [Oct.Auk

NOTES ON AVIAN •

BY DONALD C. BOUGHTON

Plate 31

INTRODUCTION To suggestto the ornithologistthat his birds are hoststo a variety of interestinganimal formswhich have elaboratedmarvelously adapted modes of life within the arian body, is perhaps,to pressthe point too far. The hint, however, that some of these , as parasites,are the causesof severediseases in birds shouldarouse his concern. The Coccidiacomprise one groupof theseparasites. Coccidiaare one-celledanimals which grow and multiply in the epithelialcells of varioushigher animals,often in the liningof the intestine,causing destruction of host tissues. An end-product of the multiplicationcycle within the hostis the microscopicspore (oocyst) which passesfrom the host body in the fecal discharge. In most casesthe coccidianspore requires a developmentalperiod (sporulation)in a moist place outsidethe host, in order to producewithin itself the minute forms (sporozoites)which are capableof beginningagain the parasitic multi- plicationwithin a new host. Shoulda susceptiblebird ingesta few 'ripe' sporesof an appropriatearian coccidian,the latter would becomeestab- lished in the bird; the bird would then become'infected.' The resulting disease is called coccidiosis. Sincecoccidiosis is a seriousand widespreaddisease of birds,it may prove of interestto ornithologiststo presentbriefly a few factsregarding: (1) the two typesof avian Coccidia;(2) coccidiosisin smallbirds; (3) examination and sourcesof bird hosts;and (4) the distributionof Coccidiaamong bird groups. Two TYPES oF AVIAN COCCIDIA The Coccidiaof birds are divided into two genera, and , whichare as distinguishableto the protozoologistas are Turdusand Zono- trichia to the ornithologist. Morphologicaldifferences are most apparent in the mature spores. When first dischargedfrom the bird, the spores containrounded masses of protoplasmand thoseof Isosporaand Eimeria look very much alike (P1.31, figs.1, 3). However, in the courseof several hours or a few days, dependingupon the coccidianspecies involved, the cysticcontent undergoes characteristic changes. To facilitate this develop- ment, fecal material containingspores may be culturedin 2 per cent potas- sium-bichromatesolution. The spore(oocyst) of Isosporaforms two sec- ondary cysts (sporocysts)shown in Figure2 (Plate31). Eachsecondary

• From the Department of and Plant Pathology, Rockefeller Institute for Medical Research, Princeton, New Jersey. Vol.1937 J BovGv•'rol,•,Noteson Arian Coccidiosis 501 cyst actuallycontains four minute,infective forms (sporozoites), but these are not readily madeout in detail. The sporeof Eimeria formsfour secon- dary cystsas shownin Figure4. Each of thesecontains only two infeetive forms (not readily made out in detail). For detaileddrawings of various eoeeidianspores the readeris referredto Becker(1934). The microphoto- graphspresented here faithfully reproducethe appearanceof the sporesas seenunder the microscope. Variousspecies of Eimerlaare responsiblefor the eoeeidiosisin quail, pigeons,and . For a reviewof eoeeidiosisin thesebirds the reader is referredto Becker(1934) and for a detailedstudy of poultryeoeeidiosis to Tyzzer (1929)and Tyzzer et al. (1932). No authenticease of eoeeidiosis in poultry due to Isosporahas beenreported. Likewise,with a possible exceptionto be noted later, Eimeria is not found in perchingbirds. In 1910, Hadley condemnedthe House Sparrowand other small birds as eartiersof the poultry disease. Actuallythere is no evidenceto support this accusation,as has beenshown by severalworkers (Smith and Smillie; Johnson;Boughton, 1929). To a limited extent, sparrowsmay carry Eimerianspores mechanically, but they certainlyare not naturalreservoirs for poultry eoeeidiosis. Coeeidiaof the genusIsospora are found in many birds, especiallypas- setines. A recent survey (Boughton,1938) has shown that 173 spedes and subspeciesof birds have been reported as hostsof Isospora. One hundredand forty-sevenof thesebelong to the order Passeriformes,while the remainingtwenty-six are scatteredthrough eight other orders. When a sufficient number of individuals is examined, the incidenceof infection is found to be relatively high in most of thesebird species. For the English Sparrowit is practically100 per cent(Boughton, 1937). In the summerof 1933 the writer obtained the following records for Isospora from birds banded at the Baldwin Bird ResearchLaboratory: Catbird (Dumetella carolinensis),8 out of 11; Eastern House Wren (Troglodytesaedon aedon), 26 out of 45; EasternSong Sparrow (Melospiza melodia melodia), 82 out of 91; EasternField Sparrow(Spizella pusilla Fusilla), 10 out of 11; Eastern ChippingSparrow (Spizella passerlna passerina), 13 out of 16. The inci- denceis high alsoin troupialsand othercagebirds. CaptiveBirds of Para- dise are commonlyinfected with an Isosporawhich has recently been de- scribedas a newspecies (Boughton, 1937).

COCCIDIOSIS IN SMALL BIRDS Typical coccidiosisin small birds causedby coccidiabelonging to the genusIsospora has been reported by variousEuropean workers (Condorelli and Fiore,Labb•, Laveran,Sj6bring, Wasielewski). The diseaseis similar in many respectsto eoeeidiosisin poultry. An infeetlonmay eventually 502 BOUGHTON,Noteson Arian Coccidiosis [Oct.['Auk

lead to destructionof the intestinal epitheliumwith subsequentloss of appetite, emaciation,droopiness, diarrhea, and finally death due to acute enteriris. Sjrbfing reports finding adult birds in nature heavily infected. When approached,such birds could make only feebleattempts to fly away, and when capturedand caged,remained quiet, squattingon the abdomen, and wouldneither eat nor drink. Death usuallyfollowed shortly. Nestlings were found with severeinfections; sometimes they would be pushedfrom the nestsand left to die. Wasielewskireports an epidemicwhich caused severelosses in his stockof experimentaleanafies. Observationsof the presentwriter on the diseasein HouseSparrows may be summarizedas follows. Nestlingsand juvenilesin Nature are heavily infectedwith Coeeidia. Althoughthe daily dischargeof enormousnumbers of sporesmust certainly destroy large numbers of intestinal cells, many young birds survive their initial infectionswithout apparent discomfort. Perhapssome do succumbto eoeeidiosis.Unless brought to our attention in epidemicform eoeeidiosismight go unnoticedas a "natural" causeof death for birds in Nature. There is certainly sufficientevidence, however, indicating that it can be a fatal diseaseunder certain conditions. For ex- ample, in juvenile and adult sparrowswhich normally maintain chronic infections,apparently indefinitely,fatal infectionscan readily be induced by feedingheavy suspensionsof infectire spores. On the fifth or sixth day after inoculation, the bird exhibits characteristicsymptoms. The feathersare fluffedout; the head is kept under the wing much of the time. There is weaknessof the legsresulting in a squatting position,loss of ap- petite, and a drop in body temperature. When cagedwith others,an inocu- lated bird is irritable and peeks viciously at its fellows when disturbed. Death usually occursabout the seventhday after inoculation. An English Sparrowsix days after inoculationis shownin Figure 5 (Plate 31). This bird died two days later. Under ordinaryconditions in Nature, birds are not likely to ingestat one time suchlarge numbersof infectire sporesas are given in these fatal, experimentalinoculations. However, further investigationis requiredto determineto what extent natural conditions may permit the developmentof fatal infections. Passefineeoeeidiosis differsfrom poultry eoeeidiosis(and avlan also)in that relatively little resistanceto subsequentinfection is built up duringthe first infection of the young bird. Figure 6 (Plate 31) showsa typical sectionof the upperintestine of a naturally infectedsparrow killed late in the summerof its first year. The Coeeidia are visible as dark, rounded bodies within the epithelial cells; there is no evidenceof tissueresponse. Most of the parasitesshown in Figure 6 are maerogametoeytes('female forms') at the characteristicstage for 3 p.m., at whichtime the hostwas killed. Had their normalgrowth Vol.1937 54]J BOUGHTON,Noteson Arian Coccidiosis 503 and developmentbeen permitted to continue,these forms would have been dischargedin the feeal material about 6 p.m. as sporeslike thoseshown in Figure 1. Chronic infections are common in domesticcanaries, and as such are potential sourcesof trouble. In small pet shopsin severalcities of the United States and in several research laboratories, the writer has found from 15 to 50 per centinfection among canaries. In 1930,through the co- operationof the R. T. French Company,the writer was able to examine feeal samplesof a few privately ownedcanaries. Ten per cent showed ooeystsof Isos29,ora.The birds were individualpets and had received routine care in the homefor a year or more prior to the examination. Unfortu- nately, the phenomenonof daily periodicityin the appearanceof ooeysts wasnot knownwhen this surveywas made, and hencethe sampleswere not taken at the most appropriate'time of day. However, it is evident that canariescan maintain chronic infectionsfor considerableperiods under averagecare in private homes. The mostlikely explanationof this condi- tion is that birds reinfeet themselves from time to time with small numbers of infectire spores,in spite of the daily cleaningof easefloor and perches. The sporesof Isos29orafrom birdsare probablyinfectire ten to twelvehours after beingdischarged from the host body. One shouldconsider also the ability of the Coeeidiato maintainthemselves by continuousmultiplication within the host tissues. In ebrohie,low-grade infections it appearsthat a balance is maintainedbetween host and parasite,such that the host can go • •roughlife without apparentdiscomfort. Under routineeasing condi- tion;•, captivebirds may neverhave access to sufficientnumbers of infectire spo•ss to causetrouble. It is alwayspossible, however, that the balance may be upset by someextraneous factor. Certainly the chroniceases are eartiersand constitutea reservoirfor the propagationof the parasites. Taere is no treatment known for eoeeidiosis in small birds. Preventive measuresagainst infection involve cleanlinessin the careof birds and the removal of obviouslyinfected individuals, the point being to reducere- peatedingestion of infectire spores. Sporesare usuallypassed in large numbersbetween 3 p.m. and 9 p.m. (Boughton,1933). They canreadily develop,on the easefloor or in the water dish,so as to be infectire,pre- sumably,the next morning. It may sometimesbe necessaryto adjustthe cleaningschedule in orderto eliminateeach daily batchof spores.Periodic microseopleexaminations are helpfulfor estimatingthe degreeof infection in a groupof birdsand for singlingout offensivecarriers.

EXAMINATION AND SOURCESOF BIRD HOSTS The presenceof Coccidisin birdscan usuallybe determinedby micro- scopicexamination of the fecesof living specimensand of the intestinal 504 BOUGHTON,Noteson Arian Coccidiosis toot.[Auk

contents or mucosalscrapings of killed specimens. Ordinary smearprep- arationsare satisfactoryfor demonstratingthe sporesunless the infection is very light, in which easeit may be necessaryto resort to concentration by centrifugation. Often, however, one can take advantage of the daily periodicityexhibited by eoeeidialspores, which resultsin a natural con- centrationfor certainhours of the day. As suggestedabove, the sporesof Isosporain many passerincinfections are to be found only in feeal material passedduring the afternoonand early evening,with a peakat approximately 6 p.m. that is characteristic. In pigeons,which are parasitizedby Eimeria, 80 per cent of the daily output of sporesis to be found in the feeal material passedbetween 9 a.m. and 3 p.m. (Boughton,1934). Examinationof living birds has the followingadvantages: the birds need not be sacrificed; the sporeswill sporulatenaturally when cultured, whereasthey are often injured by an abnormalstay within a dead host; often the observercan make sure,by controllingthe feedingof the bird, that the sporesseen are derivedfrom the hostitself and not from materialrecently ingested. Killed specimenspermit macroscopicexamination of organs for gross lesions; microscopicexamination of mueosalscrapings for the tissuestages of the parasite;and, if the bird is freshlykilled, fixation of tissuesfor histologieal studies. In all examinationsone shouldguard against the possibilityof confusingmultiplication stages of differentparasites and the misinterpreta- tion of the presenceof a few extraneousspores. This last point is emphasized becausemistakes have beenmade by someinvestigators who have reported the presenceof Coeeidiain certainhosts which in reality had only acciden- tally ingestedspores belonging to anotherhost. Museumsand zoologicalgardens are invaluablesources of bird parasites. Unfortunately, as far as Coeeidiaare concerned,these sources have been almostentirely neglectedin the past. Expeditionssent out to collectbirds actually destroylarge numbersof associatedProtozoa. It is to be hoped that the parasitologistwill find it possiblein the future to work in coopera- tion with publicand private institutionsin the study of Coeeidiaof birds. The present writer has been most fortunate in securingthe aid of many ornithologistsand institutionsin his variousstudies. It is a pleasurehere to acknowledgethe cooperationof the following:Mr. Charles Stahnke of the MilwaukeeZoological Garden; Mr. S. PrentissBaldwin and his staff of the Baldwin Bird ResearchLaboratory, GatesMills, Olfio; Dr. Dora P. Henry of the University of Washington;the R. T. French Company, Rochester,N.Y.; Mr. Lee Crandall of the New York ZoologicalGardens; Louis Ruhe, Inc., New York City; and the proprietors of various pet shopsin severaldifferent cities. Vol.1937 54'1J BOUGHTON,Noteson Arian Coccidiosis 505

DISTRIBUTION OF COCCIDIA AMONG BIRDS The wholesaleparasitism of a specializedgroup of vertebrates(Aves) by hlghlyadapted Protozoa (Coccialia) presents an opportunityfor studyinga variety of problemsof broadbiological significance. For example,there is the problemof parallelismin evolutionof hostand parasite. Sometimein their past historiesthe two generaEimerla and Isosporahave parted company. The accompanyinglist showsthat Coccldia have been reportedfrom severalorders of birds. In most casesonly one genusis foundin any oneorder, and, in general,Eimeria is the dominant form in the lowerorders, and Isosporain the higher. (The positiveorders of birds are ]{stedin accordancewith Wetmore'sclassification.) Observations are lackingfor severalgroups and only meagernegative records are avail- able for others. Perhapsornitho]oglsts having specialopportunities to ex- amine certainbird groupscan add to our knowledgeof the distributionof Coccidiain birds. In the writer's opinion certain observationsrequire verification,as is suggestedin relevantnotes in the followinglist. Ordersfor whichCoccidia have been reported

PELE CANIFORMES Eimeria E. roscoviense(Labb6, 1893) in Phalacrocoraxaristotelis (= P. cristatus : P. graculu•), cormorant,by Labb6 (1896 and 1899). E. urn•la Hoare, 1933, in P. carbo lugubris, cormorant.

ANSERXFORMES Eimeria E. truncata(Railliet and Lucet, 1891) in kidney and E. anserisKotlan, 1932, and possiblyother speciesin intestine of Anser an•ser,goose. Vide Becker (1934). FALCONIFORMES Isospora I. buteonisHenry, 1932, infive speciesof hawks and I. sp., Hegner and Chu, 1930, in kite and falconet. Vide Boughton(1938). Author's note: Eumonosporatremula Allen, 1933, amended to Caryosporatremula (Allen, 1933) Hoare, 1934, reported from Cathartesaura septentrionalis, Vulture, may very probablybe a reptilian parasite. GALLIFORMES Eimeria; Isospora(?) Severa]species of Eimeriain chickens,quail, turkey, ptarmigan,pheasant, peacock. Vide Becker (1934). I. lyruri Galli-Valerio, 1931, in Lyrurus tetrizctetrix (L.), Black Grouse, and Tetrao urogallu• urogallusL., Capercaillie. Vide Galli-Valerio (1931, 1932). Author's note: Becauseof the preponderanceof recordsof Eimeria for this order and the meager details reported by Galli-Valerio, confirmation of the occurrenceof Isosporain the two hostslisted is greatly to be desired.

GRUIFORMES Eimeria E. paludosa(Leger and Hesse, 1922) in Fulica atra atra L., Gray-black Coot, and Gallinula chloropuschloropus (L.), Moor-hen. Author's note: This coccidianwas originally placedin a new genus,Jarrina, but it properly belongsin Eimeria, as Hoare (1933) has shown. 506 BOVaHTO•,Notes on Arian Coccidiosis tOct.[Auk

CHAltADRIIFORMES Etmeria; Isospora E. roscoviense(Labb6, 1893) in nine speciesbelonging to the familiesCharadriidae, plovers,etc., and Scolopacidae,sandpipers, etc. Vide Labb6 (1896, 1899). Isospora in two speciesof Charadriidae. Vide Boughton (1938). Seven speciesof family Laridae, gulls and terns, reported negative by Labb• (1893a). Author's note: Further observations on birds of this order would be of considerable interest be- causeboth Eimeria and Isosporahave beenreported. COLUMBIFORMES Eimeria E. labbeanaPinto, 1928, and E. columbarumNieschulz, 1935, in the domesticated pigeon. Vide Becker (1934) and Nieschulz(1935). CUCULIFORMES Isospora Isosporareported from onespecies in eachof two families. Vide Boughton(1938). STRIGIFORMES I sospora I. buteonisHenry, 1932, in two speciesand I. henryi Yakimoff and Matikaschwili, 1932,in a third. Vide Boughton(1938). " CORACIIFOR•ES Isospora Isosporareported from four speciesrepresenting three families. Vide Boughton (193S). PIC•FOR•ES Isospora Isosporareported from six speciesrepresenting two families. Vide Boughton (193S). PASSER•FOR•aES Isospora Isosporareported from 147 speciesand subspeciesrepresenting 27 families. Vide Boughton (1938). Author's note: Labb• (1893a) reports Eimeria roscoviensefrom the White Wagtail (Motacillaalba); this observationhas not beeenverified by other workersalthough Labb• (1893) and alsoLaveran (1898) report Isosporain this host.

ORDERS FOR WHICH COCCIDIA HAVE NOT BEEN REPORTED Struthioniformes(1); Rheiformes;Casuariiformes (2); Apterygiformes; Tinamiformes;Sphenisciformes; Gaviiformes; Colymbiformes (3); Ciconi- iformes;Psittaciformes (4); Caprimulgiformes;Micropodiformes (5); Coli- iformes; and Trogoniformes. Author'snote: Limited negativerecords are availablefor the five orders designatedby numbers. Theseare: (1) two Ostrichesnegative (author's observation);(2) oneCassowary, one negative(author's observation); (3) negativerecord for Podicepscristatus cristatus (L.) (= Vanelluscristatus Meyer and Wolff), Great CrestedGrebe, by Labb4 (1893a); (4) several parakeets,parrots and macawsnegative (author's observation); and (5) onehummingbird negative (author's observation). There are no observa- tions on the remainingorders. Thereis alsothe problemof host-parasitespecificity. Barnyard chickens are continuallyexposed to sporesof Isosporadropped by sparrowsand yet they do not becomeinfected with speciesof that genus. Similaropportuni- Vol.1937 541J BOUGHTON,Noteson Arian Coccidiosis 507 ties for quail to becomeinfected with sporesfrom passefinebirds must exist in Nature. Specificityis marked for the generaof avian Coccidia. Perhapsit will prove to be so for speciesalso. Speciesdetermination in Coccidiais more difficult,in the writer's opinion,than somedescribers of specieshave chosento make it. Does each bird specieshave its own coc- cidian speciesor can one of the latter infect a variety of birds? These questionshave morethan academicinterest. Answersto them wouldshed light on the problemsdealing with the invasionof new territoriesby intro- ducedbird speciesand the ability of severalhost species to occupythe same geographicalrange. A wealth of informationregarding the evolutionand distributionof the hostsis alreadyavailable in the archivesof the ornitholo- gist. When the Coccidiaof birdshave beenmore thoroughly described and the resultsof crossdnfectionexperiments are available for analysis,the parasitologistmay be able to offer suggestionson relationshipsof avian speciesbased on a knowledgeof their parasites. The widespreaddistribution of Coccidiaamong bird groupssuggests the useof theseparasites and hostsfor studieson severalother problems, which may be mentionedhere briefly. BecauseCoccidia of wild birds represent natural parasitesliving in associationwith hostswhich have not been sub- jected to such artificial alterationsof physiologyor environmentas are often imposed'upondomesticated animals, studieson coccidiosisin wild birdsmay disclosefeatures of the diseasenot readilyrevealed, for example, in poultry work. Of interestto studentsof humanand animal diseasesare the problemsof host resistanceand immunity to sporozoandiseases, in- cludingmalaria as well as coccidiosis.Experimental work on the genus Isosporain relation to its many arian hosts may prove of significance. Also, as pointed out above, there is sufficientevidence to condemnthe genusIsospora, at least in certain cases,as a pathogenicparasite of small birds; as suchit shouldbe studiedwith an aim toward treatment and control.

]{EFERENCES CITED BECKER,E. R. 1934. Coccialiaand coccidiosisof domesticated,game and laboratory animals and of man. Ames, Iowa, 147 pp. BOUGHTON,DONALD C. 1929. A note on coccidiosisin sparrowsand poultry. Poult. Sci., 8: 184-188. 1933. Diurnal gameticperiodicity in arian Isospora. Amer. Journ. Hyg., 18: 161-184. 1934. Periodicity in the oocyst-productionof the pigeon Eimeria. (Abstract.) Journ. Parasitol., 20: 329. 1937. Studieson oocyst-productionin avian coccidiosis.II. Chronic Isosporan infectionsin the sparrow. Amer. Journ.Hyg., 2õ: 203-211. 1937a. Isosporavolki sp. n., a new avian coccidian. Journ. Parasitol,23: 97-98. 1938. Avian hostsof the genusIsospora (Coccidia). Ohio Journ. Sci. (in press). 50S BOVGHTON,Noteson Arian Coccidiosis [oAcU•t.

CONDORELLI,M., ANDFIORE, C. DE 1892. Un casodi sporospermosiintestinale nel Coccothraustesvulgaris. Boll. Soc. Rom. Studi Zoolog.,1: 68. GALLI-VALERIO,B. 1931. Notesde parasitologie.Centralbl. f. Bakt., etc. I. Orig., 120: 98-106. 1932. Notesde parasitologieet de techniqueparasitologique. Ibid., 125: 129-142. HADLEY, P. B. 1910. Studiesin arian coccidiosis.III. Coccidiosisin the EnglishSparrow and other wild birds. Ibid., 56: 522-523. JOHNSON,W. T. 1923. Avian coccidiosis. Poult. Sci., 2: 146-163. LABB•, A. 1893. SuE les coccidiesdes oiseaux. Comptes Rend. Acad. Sci., Paris, 116: 1300-1303. 1893a. SuEles coccidiesdes oiseaux. Ibid., 117: 407-409. 1896. Rechercheszoologiques, cytologiques et biologiquesSUE les coccidies. Arch. Zool. Exper., seE.3, 4: 517-654. 1899. "Sporozoa," in Das Tierreich, 5: 71-72. Berlin. LAVERAN,A. 1898. SuE les modes de reproductiond'Isospora lacazei. ComptesRend. Soc. Biol., Paris, 5 (10): 1139-1142. LEGER,L,, ANDHESSE, E. 1922. Coccidiesd'oiseaux palustres. Le genre Yarrinan.g. Comptes Rend. Acad. Sci., Paris, 174: 74. NIESCHULZ,O. 1935. Ueber Kokzidien der Haustauben. Centralbl. f. Bakt., etc. I. Orig., 134: 390-393. HEGNER,R. W., ANDCHU, H. J. 1930. A survey of protozoan parasitesin plants and animals of the Philippine Islands. Phfiippine Journ. Sci., 43: 451-480. SZSBR•NG,N. 1897. Beitr•ge zur Kenntnis einigerProtozoen. Ibid. 22: 675-680. SMITH, T., ANDSMILLIE, E. W. 1917. Note on coccidiain sparrowsand their assumedrelation to blackhead in turkeys. Journ. Exp. Med., 25: 415-420. T•ZZER, E. E. 1929. Coccidiosisin gallinaceousbirds. Amer. Journ.Hyg., 10: 269-383. T•ZZER, E. E., THErLER,H•S, • JONES,E. E. 1932. Coccidiosisin gallinaceousbirds, II. A comparativestudy of speciesof Eimeria of the . Ibid., 15: 319-393. WASIELEWSKI,T. VON 1904. Studienund Mikrophotogrammezur/(enntnis der pathogenenProtozoan. i Heft. III. Ueber den Erreger einer Coccidienseuchebei VSgeln(Diplo- spora lacazei), 69-88. Leipzig. WETMORE,ALEXANDER 1934. A systematicclassification for the birds of the world, revisedand amended. SmithsonianMisc. COIL, 89 (no. 13): 1-11. Tin; Ave, Von. 54 PnaT•; 31

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AVIAN COCCIDIOSIS Vol.1937 54'1J BOUGHTON,Notes on Arian Coccidiosis 509

EXPLANATION OF PLATE 31 Fig. 1.--Unsporulated spores (oocysts)of Isospo•a from the domesticcanary. X 475. Fig. 2.--Sporulated spores(oocysts) of Isosporafrom the domesticcanary. X 475. Fig. 3.--Unsporulatedspores (oocysts) of Eim•a from the domesticpigeon. X 475. Fig. 4.--Spomlated spores(oocysts) of Ei•a from the domesticpigeon. • 475. Fig. 5.--English Sparrowwith coccidiosis.Six days after inoculationwith infec- tave sporesof Isospora. Fig. 6.--Section of intestineof EnglishSparrow parasitized by Coccialiaof genus Isospora. X 80.' [Photographsby J. A. Carlile.]

Departmentof Zoology, Universityof Georgia Athens, Georgia