OF THE ALIMENTARY TRACT 233 



forms. Young large forms in stool or culture are 

 delicate of structure. 



Division of the body in the stool is ordinarily by 

 binary fission, the nucleus dividing apparently by 

 mitosis and the two daughter nuclei becoming lo- 

 cated at opposite poles. There is then a constriction 

 of the body, both peripheral zone and central body, 

 equally, to form symmetrical cells, or there may be 

 multiple fission, with 2, 4, 6, 8, or more, similar 

 daughter cells, all within a mucoid envelope which 

 is apparently a product of the organism. Peripheral 

 budding and endosporulation of species named B. 

 gemmagina and B. sporogina, in addition to binary 

 fission, may be studied in cultures. 



Blastocystis is widespread in nature as a parasite 

 of the intestine of many animals. It is not known 

 as a free living body and is probably transmitted 

 from person to person and from animal to animal 

 through the contamination of ingested materials by 

 fecal matter. It is an inhabitant of the colon in 

 man. It is favored by inflammatory states of the 

 intestine and from time to time it has been indicted, 

 although not very seriously, as playing a causal 

 role in intestinal disease. The writer (1923) re- 

 corded its presence in rectal ulcers, where it increased 

 in size and numbers over those in the feces of the 

 host, and exhibited active division. 



The organism is readily found in examination of 

 fresh wet preparations and, while it may be confused 

 with protozoan cysts by the inexperienced, its char- 



