4io 



SPECIFIC MICRO-ORGANISMS 



forms about the fertilized cell and within this the cell divides 

 into two and later into four embryo parasites, which are enclosed 

 in pairs in two spores within the cyst. This escapes with the 

 feces of the mole and serves to infect a new host. 



The invasion of the epithelium produces a severe diarrhea in 

 the mole often resulting in death. If the animal survives for 

 five days, until after the spores are formed, it then 

 usually recovers. 



Eimeria Stiedae (Coccidium Cuniculi). This 

 very common parasite of the rabbit was first de- 

 scribed by Lindemann in 1 86 5 . It lives and grows 

 within the epithelial cells of the small intestine, of 

 the bile passages and of the liver of rabbits suffer- 

 ing from coccidiosis, and its oocysts are found in 

 the intestinal contents and in the feces of such 

 animals. The oocyst is an elongated oval, vari- 



able in width fr m IX to 28 ^ and in len g th from 



24 to 4Qju. It contains, when fully developed, four 



, , , . , 



sporozoits are de- spores, each of which contains two embryo para- 

 s jj- es or sporozoits. These gain entrance to the 



FIG. 1 80. Ei- 

 meria steidtz. 

 Oocyst containing 

 four spores, in 

 each of which two 



pyle is 



low. ~ (From Do- intestine of a new host along with the food and the 



flein after Metz- , -, ,. -, 



ner ^ pancreatic digestion makes an opening at one end 



where the wall is exceedingly thin, the micropyle, 

 and through this opening the wedge-shaped sporozoits escape. 

 They penetrate epithelial cells, in which the parasite becomes 

 rounded and grows to a diameter of 20 to 5o/z, destroying 

 the host cell. The nucleus divides many times and after 

 it the cytoplasm, so as to form numerous spindle-shaped 

 young cells, merozoits of agametes, which penetrate new epi- 

 thelial cells and pass through the same cycle. This cycle of 

 asexual multiplication, schizogony, is repeated many times and 

 may lead to extensive destruction of intestinal mucosa, of the 

 epithelium of the bile ducts and of liver substance. Some of 

 the growing parasites become differentiated into sexual elements. 

 The female cell, macrogametocyte, accumulates numerous large 



