592 J(iiu4 W. Raff: 



Both these forms I can say are present in the frogs I have 

 examined, occurring sometimes together, sometimes separately, 

 though it has often been difficult to distinguish between them, 

 and at times quite impossible. The main difference between the 

 two is the presence of an undulating membrane in Trichomonas 

 in place of the posterior flagellum of Trichomastir, otherwise a 

 description of the one would hold good for the other also. The 

 body has an average length of about 12 /x and is oval, or 

 spindle-shaped. The protoplasm is clear, excepting for the 

 food granules at the posterior end and the nucleus at the 

 anterior (Figs. 19 to 22). The axostyle is sometimes A'isible 

 as a clear rod running through the body and projecting at the 

 posterior end. giving the body a spindle-shaped appearance ; at 

 other times it seems absent altogether and the body then 

 assumes an oval shape. Its form changes, however, very rapidly 

 and becomes amoeboid, and it is in this amoeboid stage in 

 particular that the two trichomonads appear so alike, and in 

 fact are quite indistinguishable from one another. A remark- 

 able form of movement was shown by one individual which 

 appeared to be in a dying condition. A peculiar elongated 

 process was forced in and out by sudden contractions and expan- 

 sions. The whole body was amoeboid and the process looked 

 as if it might have been either the undulating membrane drawn 

 out from the liody. if it avos a Trirh<t)n(})ia^, or the flagella fused 

 to the bodv and then extended, if a Tricliomastir (Fig. 23). 



A somewhat similar movement was observed by Dobell in 

 Trirliomastir serpentis. 



In the fresh forms the axostyle is sometimes swollen out 

 near its posterior end as represented in Fig. 22, and this may 

 appear to become confluent with the body when the central 

 portion of the axostyle is disappearing. 



LITERATURE. 



(1) Bezzenberger. — "' Uber Infusorien aus asiatischen Anuren." 



Arch. f. Protistenk. Band 3, 1904. 



(2) Blochmann, F. — '' Bemerkungen uber einige Flagellaten." 



Zeitschr. f. wiss. Zool.. Band 40. 1884. 



