OF THE ALi:\IENTARY TRACT 



225 



organism. Sometimes the first division, into sporo- 

 blasts, has occurred in fresh feces and there are two 

 smaller enclosed bodies instead of one. Further de- 

 velopment, the formation of sporocysts by the two 

 sporoblasts, the division of each sporoblast into four 

 sporozoites, leaving the rounded granular residual 

 body in each sporocyst, has been induced and de- 



FiG. 36. — Isospora belli. 

 Drawings of oocysts from human stool, x 1200. 



scribed by Wenyon and has been observed by others 

 to occur as the stool ages. The sporozoites are elon- 

 gated comma shaped bodies, the cytoplasm granular, 

 with a refractive globule in the larger end, the nucleus 

 anteriorly but indistinct. 



In feces these oocysts are to be studied in wet un- 

 stained slide preparations. Since they are large they 

 are readily picked up with the ordinary low power 

 working lens. As they are transparent they may be 



