14 



i)i;. II. It. I'.VNTii.VM <ix .wiAN (( > CI i)i( tsrs. 



Mnv.*!. 



with wliicli the iiiaci'ogM.iiH'tc iiive.sl,.s it.sflf, niiil lli«' fei'tilisod oocyst 

 so produfeil, passes out throu^'li the much ilaniiiged e[)itheliuni 

 into the lumen of tlie gut anJ thence to the outside. The epithe- 

 lium of the duodenum and cseca is sometimes entii-ely denuded 

 ])V tlie action of the many parasites that infest it, and the sub- 

 mue.o.saalso is somstimes infected by the Eimeria. 



The contents of the oiicyst, at first filling the intei-ioi- (text- 

 fig. 66, k.), gradually contract (text-fig. 66, B) towards the centre, 

 or occasionally towards one pole, and then divide (text-fig. 66. C) 

 into four round masses (text-fig. 66, D) known as sporoblasts. 

 Eich s[)orol)last becomes an oval spoi-ocyst (text-fig. 66, E) while 

 still within the oocyst, and within each ripe sporocyst two sporo- 

 zoites or germs are developed. Consequently each oiicyst gi\'es 

 rise to eight sporozMtes (text-fig. 66, F). 



Text-fiir. 66. 



Fi 



A-F. 



Stii;;('s in tlio (Icvclniniiciit oF tlu! oiicv.sts of J<Tn»eriii nriiiiii, Ms spcil ill 

 tVc'sli prciiaiiitions. 



A. Oiicyst (encvsti'il zyRoto) witli iivotoiilusm couiiilctcly tillirin- it. 



U. Older (liicyst with zvfroto (■(c.itciits t'oriiiiiit; a cfntial splicrc. .Many ^iK'li cysts 



arc ('duikI in int'uctcd ca'ca and iiilcctcd ticccs of jrr'jnse. 

 ('. Oiicyst witli four nnclt'i. aiioiit to form sporolilasts. 

 1). Oiicyst witii four round sporobla.sfs. 

 1']. Four ovoid s])oroc\sts within oiicyst. 

 F. I''ully nialurc ni'icyst with four s]iorocysts, each containing: two s|iiii-o/oitc's. 



A certain annunt of variation, as exiiiliited liy the oiicysts of 

 E. aviion), has been noticed l)y Mor.se (li)()H) in the coccidian para- 

 site of " white diarrhoea " of fowls, where the oiicysts are round to 

 oval, and from l2/i to "ir)/;. in diameter. The oocy.sts of E. aviaia 



