674 DR. H. U. FAXTHAM ON THE [j^Fiiy 3, 



Professor Miucliin when he Aviites in a, recent review : — " We 

 i-egret to see the fan)ilinr geneiic nsiiiie Coccidium replaced by 

 J'Jiincria; this is one of those many cuses where, in onr opinion, 

 rebellion against the law of priority in nomenclature is not onlv 

 lawful but imperative" ('Nature,' March 3, 1910). It woul'd 

 save much confusion if the question of zoological nomenclature 

 were settled by an international committee, as has been suggested 

 by many able workers. 



The Coocidia of birds were first recorded in fowls by Silvestrini 

 and llivolta. (1873), under the name Psorosjjei'mium avium. 

 Subsequently Railliet and Lucet (1891) recorded Coccidia from 

 fowls, naming the parasite C. tenellum. I have followed Dofiein 

 (1909) in naming the Coccidia of birds Eimeria ariam. The 

 Coccidian parasites were obtained from grouse chicks, and I have 

 succeeded in ti-ansmitting the Coccidia of grouse to fowl chicks 

 and to young pigeons. 



Ill, Methods. 



In this investigation of coccidiosis both fresh and pi'eser\-od 

 materials were used. Samples of gut contents, taken from 

 difierent regions, wei-e examined fresh, and often these have been 

 fixed wet with osraic or formalin vapour and stained by Delafield's 

 htematoxylin or by Giemsa's stain. Such smears were sometimes 

 useful for examining merozoites. 



Oocysts, because of the chitinoid and aluiost inqienetrable 

 character of their walls, had to be examined fresh. 



For preserved material, the best fixatives were found to be 

 Schatidinn's fluid (corrosive-acetic-alcohol), and Bouin's fluid 

 (pici'o-foi'mol -acetic) to which a few drops of absolute alcohol 

 were added. Schaudinn's fluid tends to shrink the tissues, while 

 Bouin's fluid retpiires much washing out. Sections, 5/,j to i^i 

 thick, were made of the duodenum and c.Tcum of infected l)ir(ls, 

 these parts of the digestive tract being especially examined. Tlie 

 chief stains used were Delafield's hsemaioxylin (either alone or 

 counterstained with Orange G or eosin), which was found to be 

 most useful, safranin and Lichtgriin, iion-luematoxylin (with or 

 without van Gieson's picro-fuchsin) and paracarmine. On the 

 whole the liaMnatoxylins pi'oved of most service, 



IV. MoiipHOLoay. 



On diluting some of the ca^cal contents or fa'ces of a gnaise 

 cliick suHering from coccidiosis, and examining the prepai'ation 

 luicroscopicallj-, numerous oval cysts are seen (PI, LVIII. i\irs. (51 

 (i6). Sometimes the cysts are also seen in the small intestine 

 just beyond the duodenum. These c>'sts may have homogeneous 

 contents, or, when older, may show four more or less Avell 

 differentiated sporocysts within them (figs. 67-70). Each sporo- 

 cyst, if ingested by another grouse, can do\eloj) two active, 

 motile germs or sporozoites (figs, 71 76). which ran penetrate 



