1910.] MORP.IOLOGY OV EIMERIA AVIUM. (587 



of the intestinal epitlielium, digestive derangenieuts are brought 

 about, a,nd consequent on this, malnutrition occurs and the bird 

 becomes very emaciated and " an?emic." Feathering also is prior 

 and ragged, leg weakness is fairly common, and a peculiar bluisji 

 tint is sometimes seen at the cere, ears and other parts. 



Distribution and Effects on Internal Oryans. 



Ebneria avium appears to be purely a pai'asite of the gut of 

 the grouse, and does not affect such gut diverticula as the liver. 

 The crop and gizzard of infected birds are rarely parasitised, 

 though they may contain oocysts in the condition in which they 

 have been ingested with food. Examination of the duodenum 

 shows that the sporocysts ingested with the food ai'e attacked by 

 the pancreatic juice (as I have proved by pancreatic digestion 

 experiments, using both natural pancreatic juice and trypsin), 

 and the sporozoites are set free. These invade the tissue of the 

 duodenum, rapidly become schizonts and multipl}^ the result 

 being that the duodenum is often riddled by the parasites, 

 and consequently inflamed. Both the villi and the crypts of 

 Lieberkiihn ai-e attacked, and the parasites have also been found, 

 though much more rarely, in the submucosa. Great hypertro^^hy 

 followed by atrophy of the epithelial host cell occurs, and the 

 tissue attacked is often reduced to a Jlnely granular, structureless 

 mass. Desquamation of the gut is common, and epithelium 

 containing various developmental stages of the parasite can be 

 found floating free in the gut contents. 



Some of the merozoites formed in the duodenum pnss down 

 the gut, reach the c«ca and re-commence their life cj'cle there. 

 Active schizogony and sporogony go on in the c?eca*, chiefly in 

 the epithelium, very rarely in the submucosa. Often the 

 ca;ca are as heavily parasitised as the duodenum, whole areas 

 being completely denuded of the epithelium, espec'ally wdien 

 the fertilised oocj'sts pass outwards into the caecal contents. 

 The walls of the cpeca are often rendered very thin and 

 tender by the action, dii^ect and indirect, of the parasite. Ripe 

 oocysts and sporocysts occur in the lumen of the cieca of dying 

 chicks. 



Podwyssozki (1890) stated that he found Coccidian oocysts in 

 the vitellus of eggs of fowls, especially in summer. He considered 

 it possible that the cysts were derived from Coccidia iii the 

 oviduct of the mother, or perhaps from intestinal Coccidia which 

 had ascended by way of the cloaca. I think that cloacal con- 

 tamination was the more probable, for I have never seen Coccidia 

 in the genitalia of adult grouse examined. 



A reflex of coccidiosis is seen in the blood of infected birds, 

 where polymorphonuclear leiicocytosis is induced. 



* Coccidiosis may sometimes occur along the entire length of the small intestine, 

 and 2;ametcs mav be formed far forward, in the duodiinum. 



4r)* 



