130 



RESEARCH IN PROTOZOOLOGY 



point at the posterior end which normally projects very little be- 

 yond the body, and they exhibit a ring of chromatic material just 

 anterior to the point of posterior emergence. In T. parva, Penta- 

 trichomonas and Hexmnastix, the axostyles tend to be more slen- 

 der, tapering gradually through the body to the posterior end 



Fig. 13. — Flagellates of rats, a, Chilomastix bettencourti, trophozoite; b, 

 same, cyst; c, Giardia muris; d, Giardia lamblia{?) ; e, Hexamitus muris; 

 f, Hexamitus pulcher. 



which is inclined to protrude considerably beyond the body. There 

 is no posterior chromatic ring, but sometimes these axostyles stain 

 rather deeply with hematoxylin. The significance of these differ- 

 ences is entirely unknown. Many other differences in axostylar 

 organization occur in many species of trichomonads in other hosts, 

 and need to be more thoroughly studied. 



In Chilomastix there is no axostyle comparable to those of the 



