J.;}2 



DISEASES DUE TO PROTOZOA 



Morphology. 



It much resembles the nagana parasite. 



There is great variation between the long and short forms, but 

 among the short forms there is an absence of the blunt-ended ones. 



The protoplasm contains many chromatin granules. 



There are no posterior nuclear forms. 



The kineto nucleus is small, round, from r8 — I'l ^ from the 

 posterior extremity. 



The undulating membrane is well developed and has bold folds. 



The tlagellum is long and free, except in the short forms, where it 

 is absent. 



The length of the organism is about the same as the T. brucei. 



No difference can be ascertained by the microscope in blood pre- 

 parations between T. gambiense and T. brucei. 



3 

 f 



.'^ 



Trypanosoma gambiense. Development in vertebrate host, a, long, slender, /', intermediate 

 and c, short, stumpy forms, found in the blood : d, e, /, non-flagellate, latent forms from internal 

 organs, x 2,000. (Original. From preparations by Fantham.) 



Animal Siisccpiibility. 



Tt is difficult to infect experimental animals from infected human 

 blood, and in this it differs much from T. brucei. 



The rat is the least refractory, but its virulence can be increased 

 by passing it through several of the same species. 



The virulence of both these trypanosomes is illustrated by the table 

 below : — 



hence T. gambiense is much more chronic than T. brucei, and this 

 test is best for the differentiation of the species. 



