SLEEPING SICKNESS 25 



blepharoplast shows the first signs of division, for its 

 substance gradually concentrates into two masses, 

 so that it looks like a dumb-bell. The root of the 

 flagellum splits into two, and the split extends to the 

 undulating membrane and the free flagellum, which 

 also become divided into two. The heads of the 

 dumb-bell-shaped blepharoplast separate, and the 

 nucleus becomes constricted and divides into two 

 also. Meanwhile, the activity of the two daughter 

 flagella is very great ; they exercise a pull on the 

 body, and gradually diverge from one another. The 

 split extends backwards, much in the way that blades 

 of scissors diverge from one another, and finally the 

 two daughter organisms lie in a straight line and 

 then completely separate into two, each practically 

 a thin replica of its parent. Occasionally the division 

 occurs in such a way that the daughter organisms 

 are unequal in size, and in consequence of this and 

 of growth, the greatest possible diversity of form 

 occurs. However, two principal types may be dis- 

 tinguished namely, long, thin forms (young) and 

 shorter and broader, stumpy forms (mature). The 

 parasites grow and multiply in the manner out- 

 lined above with the greatest rapidity. Generation 

 after generation of trypanosomes succeed one 

 another ; the blood of the man swarms with them, 

 and he shows dullness and fever. Then the man 

 commences to struggle against the parasites, and 

 the latter retreat to the internal organs, especially 

 the lungs and spleen, of their victim. There the 

 protoplasm of the parasite concentrates around the 

 nucleus and blepharoplast, the flagellum shortens as 



