TRICHOMONAD FLAGELLATES. 293 



the subject more fully in the first named form and reviewing it briefly 

 in the others. 



Trichomonas augusta Alexeieff. 



This flagellate occurs abundantly in the intestine of Diemydylus 

 torosus, Rana boylci, R. drayioni, and R. pipiens, Hyla regilla, and 

 Bufo halophilus. The following table indicates the proportions of the 

 hosts which were infected: 



The Vegetative or Premitotic Stage. 



This phase is found free in the intestinal lumen or actively moving 

 about in the mucus covering the intestinal epithelium. It is the type 

 found most frequently in our culture slides and in sterilized inoculated 

 media where it may be accumulated on the under surface of floating 

 cover glasses. 



The form of the body in this phase is distinctly pyriform, (PI. 1, 

 Fig. 4) with the larger end anterior, and its total length to tip of the 

 axostyle 2-2.5 times it greatest diameter which is located at 0.3 of the 

 total length from the anterior end. It is usually nearly symmetrical 

 as it rotates in locomotion, but in some preparations (PI. 1, Fig. 1) 

 the ventral side is flattened and the dorsal, bearing the undulating 

 membrane, is convex. The axostyle lies in the major axis of the body 

 and extends from near its anterior end to, and generally beyond, the 

 posterior limit of the cytoplasm, projecting for a distance equal to half 

 or two-thirds of the diameter of the body. 



The form of the body is frequently subject to the elongation and 

 accumulation of the cytoplasm posteriorly, even beyond (PI. 1, Fig. 2) 

 the axostyle, in the form of a subspheroidal blob which may detach 

 itself from the parent mass and slip off from the tip of the axostyle. 

 These forms in various stages of elongation and constriction are often 



