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HtflMOFLAGELLATES, OR TRYPANOSOMES. 



Describe the Structural Features of the H cemoflagellates. 



The body of a typical Trypanosome is spindle-shaped 

 and usually somewhat sinuous, and it has a delicate fin- 

 like undulating membrane along one side. The flagellum 

 arises at the anterior end where the undulating membrane 

 begins ; but instead of projecting in front, it is turned 

 back and is attached along the free border of the undulating 

 membrane, and its free terminal portion (when present) 

 projects posteriorly. When there are two flagella (as 

 e.g., Trypanoplasma of Fishes) the other one is entirely 

 free and projects anteriorly. The protoplasm of the body 

 is finely granular. Sometimes there is a distinct oval 

 vacuole, and there are two nuclei, a large trophonucleus 

 situated about the centre, and a small accessory kineto- 

 nucleus near which the flagellum arises and which con- 

 trols the locomotor activities. 



The following are important types : 



1. Trypanosoma with a single flagellum and a well- 



developed undulating membrane along the 

 body. 



2. Crithidia with a single flagellum, arising near the 



kinetonucleus which is situated beside the 

 trophonucleus, and with a short or rudimentary 

 undulating membrane. 



.3. Herpetomonas with a single flagellum, arising at 

 anterior end of body, and without an undula- 

 ting membrane. 



4. Trypanoplasma with two flagella, one free and the 



other united, for a part of its length, to the 

 undulating membrane. 



5. Leishmama which is non-flagellate at one stage. 



