TRYPANOSOMA GAMBIENSE 



529 



Moore and Breinl (1907) has already been considered (p. 332), It may be 

 noted that the occurrence of short broad forms and long thin trypanosomes 

 has been supposed to indicate a sexual dimorphism, of which at present 

 there is no evidence. Robertson (19126) considers that the short broad 



Fig. 222. — Trypanosoma gambiense (x 2,000). (A, B, and C, after Bruce, 1912; 

 D, Original.) 



A. Long thin form with fiagellum. B. Intermediate form with short flagellum. 



C. Broad stumpy form without flagellum. 



D. Small forms "from a rat inoculated with the Nigerian strain. 



trypanosome 13 to 20 microns in length is the adult blood form. When 

 proceeding to divide, growth takes place till the long forms are produced. 

 These are the dividing individuals, which give rise to the short broad forms 

 again. Robertson (19126) believes that the short broad forms alone are 

 capable of development in the tsetse fly. 



I. 34 



