120 



PROTOZOAN PARASITISM 



growth on L. E. A. medium of Boeck and Drbohlav 

 for nineteen days. 



lODAMOEBA BUTSCHLII 



There is some confusion about an amoeba of the 

 human intestine which is fairly commonly seen, the 

 cysts of which were discovered before the active form 



Fig. 21. — lodamoeba butschlii. 



A, trophozoite, B, cyst stained by iron-haematoxylon, C, cyst 

 with dark iodine stained globule. Drawings x 2000. 



and called "iodine cysts" by Wenyon ( 1916) . In the 

 active stage this amoeba resembles somewhat End- 

 amoeba coli. It usually measures 9 to 13 microns, is 

 without distinct differentiation of ectoplasm from 

 endoplasm, and is of sluggish movement. The nu- 

 cleus is invisible in unstained preparations, as con- 

 trasted to E. coli. 



The cysts, more commonly found than the vegeta- 

 tive form in stools, are of irregular shape, contain only 



