188 THE PARASITISM OF 



by the influence of one of the sporozoa {Coccidium oviforme^ 

 Leuckhart) which infests the intestine, bile ducts, and livers of 

 diseased animals, in myriads. The disease is so common in 

 certain hutches and warrens near London,* that the keepers 

 recognise it readily, and distinguish it by the " wet snout," which 

 the affected animals exhibit. It is most fatal in young rabbits ; 

 which become affected as soon as they cease to suckle and begin 

 to eat green food. They loose flesh rapidly, suffer from enteritis 

 of more or less acute character, and many die in from eight to 

 fifteen days after the initial symptoms. The adult animal is more 

 rarely infected, and, as a rule, resists the disease. The develop- 

 ment of the parasite which brings about this very fatal disease may 

 be considered in two stages, external to and within the host. 



Development External to the Body. 



The organism as it escapes from the alimentary canal consists 

 of a firm, translucent cyst, enclosing a quantity of very gran- 

 ular protoplasm, which fills the whole cavity. The cyst, which 

 is the striking feature of this period of development, is oval 

 in shape, and measures about 36 /i in length, and about 22^ in 

 breadth. Very soon after expulsion, and often while within the 



CL 



Fig. 47. — a, Coccidium showing capsule full of granular protoplasm; b^ 

 shows condensation of the protoplasm into one sphere, after two 

 days' growth external to body ; ^, division of the single sphere in- 

 to four daughter spherules, after four days' development ; d, an 

 empty ruptured cyst. (From Photographs magnified about ^00.) 



* Hutchinson, J., sen., Archives of Surgery^ Vol. iii., 1891. 



