Chapter XXIX 



THE TRYPANOSOMIDAE 



The Trypanosomidae comprise two genera 

 (i) Trypanosoma, (2) Trypanoplasma. 



Trypanosoma. Trie genus is characterised by the 

 possession of a longitudinal undulating membrane, 

 the thickened border of which takes its origin 

 posteriorly from a blepharoplast, and terminates 

 anteriorly in a free flagellum. Division takes place 

 longitudinally. 



Structure of Trypanosomes. In the gut of the 

 louse certain non- flagellate forms of T. lewisi are 

 described, which have a single oval nucleus only. 

 From this nucleus eventually arises by division the 

 blepharoplast, or nucleus regulating motility. This 

 shews that this structure is nuclear in origin and, more- 

 over, as the flagellum now appears at the end of the 

 young developing trypanosomes where the blepharo- 

 plast is, this flagellum-bearing end is the anterior one ; 

 and it is only later that it takes up its ordinary posterior 

 position. Besides the blepharoplast, the undulating 

 membrane, and the flagellum, mynonemes are also 

 described. These ectoplasmic fibres are not generally 

 seen in the ordinary methods of staining. They are 

 most readily demonstrated in large trypanosomes like 

 T. rotatorium or T. theileri, especially if the trypano- 

 somes have been eviscerated by the pressure of making 

 a blood film or by the action of macerating fluids. 



Besides these details of minute structure, some 

 authors consider that trypanosomes exhibit 



Sexual Differences. These differences are not 



