GENUS: TETRAMITUS 



309 



to the genus Tetramitus, as Dobell suspected, though the absence of cyto- 

 ' stoma is against this view. 



As noted above, the Monocercomonas described by Chatter jee (1917) 

 from the human intestine probably has only three flagella, and not four, 

 and should not be included in this genus. 



Aragao (1916) established the new genus Coj^ro/z^rtA'/ia? for a flagellate with 

 four anterior flagella, which ap- 

 peared in cultures of human and 

 rat faeces in egg-albumen water 

 (Fig. 148). The organism is pear- 

 shaped, with a blunt anterior 

 end, at one side of which is a 

 cytostome. The length of the 

 body is 16 to 18 microns and the 

 breadth 7 to 9 microns. Smaller 

 forms, however, occur. The 



Fig. 147. — GMlomitus cavice from 



THE C^CUM OF THE GuiNEA-PiG 



(x ea. 2,000). (After Fonseca, 

 1916.) 



Fig. 148. — Copromastix prowazelci : A Copro- 

 zoic Flagellate appearing in Cultures 

 of Human and Rat F^.ces (x ca. 3,000). 

 (After Aragao, 1916.) 



1. Usual type. 2. Dividing form. 



flagellates multiply by binary flssion. The blepharoj^last from which the 

 four flagella take origin first divides into two, some of the four flagella re- 

 maining with one portion and the others with the other portion. The nucleus 

 divides by mitosis, and this is followed by division of the body. New flagella 

 are formed from the blepharoplast till each daughter individual has four. 

 Aragao names the flagellate Cojxromastix prowdzeki, but it corresponds very 

 closely with Tetramitus rostratus, a free-living form first seen by Perty 

 (1852). It is probable that it as well as Copromastix aragaoi cultivated 

 from human faeces by Yakimoff (1925) are actually this species. 



Bunting (1922) obtained by culture from the csecal contents of rats 

 an amoeba which after reproduction in this form became transformed into 

 a flagellate of the Tetramitus type, with four flagella, a lateral cytostome, 

 and contractile vacuole. After reproduction in the flagellate stage had 

 taken place, reversion to the amoeboid phase occurred. Spherical cysts 

 6 to 18 microns in diameter were produced by the amoebse. Rats and mice 



