1919] McCulloch: Life Cycle of Crithidia and Trypanosoma 179 



the evolution of a trypanosome has probably taken place from a 

 crithidial flagellate rather than from a herpetomonad or leptomonad 

 flagellate. 



4. The process of multiple fission in the somatella of C. euryoph- 

 thalmi is fundamentally like the multiple fission (sphere formation) 

 of T. lewisi and also like the multiple fission (somatella) of the tricho- 

 monad flagellates. In each of these flagellates the nucleus, parabasal 

 body, blepharoplast, and flagellum, or flagella, are concerned in the 

 process. In each after multiple fission plasmotomy occurs. 



5. The process of multiple fission by endogenous budding in the 

 life-cycle of C. euryophthalmi tends not only to establish another link 

 in common between the life cycles of Trypanosoma (e.g., T. gambiense) 

 and the life cycle of Crithidia but also to link the life cycle of 

 Crithidia more closely to the lower protozoan forms which contain 

 numerous Leishmania-like bodies in their life cycles. 



6. The endogenous buds in the life of C. euryophhtalmi are com- 

 parable to the latent bodies in the life-cycle of T. gambiense. 



