1913.] 



causing Disease in Man in Nyasaland. 



407 



Chart 7. — Curves representing the Distribution, by Percentages, in respect to Length, 

 of 3600 Individuals of the Trypanosome of the Human Strain, and 2500 of the Wild- 

 game Strain. 



17 



16 



15 

 W 

 IS 

 IZ 

 <0 || 



a) 



■or) 10 



i 9 

 s: 8 



o 7 

 >- 6 



a. 5 



,.A- 



2 

 I 



Microns 



13 



14 



15 



16 



17 



18 19 



20 



21 



22 



23 



24 



25 



26 



27 



28 



29 



JO 





J 2 



33 



34 



35 





•37 



3fl 









































































































































WW Game Strain. 





































































— — 1 1 union milium. 



































































































































P-- 

































































































r 



























































































































-QL, 

























































































































































































































"Q. 













































































































to. 





-O- - 







Table XX. — Percentages of Posterior-nuclear Forms found among the Short 

 and Stumpy Varieties of the Trypanosome of the Human and Wild-game 

 Strains. 



Date. 



Strain. 



Average, 

 percentage. 



Maximum, 

 percentage. 



Minimum, 

 percentage. 



1912 

 1912 



Human 

 Wild-game 



21 -1 

 26 -2 



52 -0 

 33 4 



, 2-0 

 8-4 



Conclusions. 



1. The five Wild-game strains resemble each other closely, and all belong 

 to the same species of trypanosome. 



2. The Wild-game strains and the Human strains, although they differ to 

 some extent, also belong to the same species. 



3. This species is T. rhodesiense (Stephens and Fantham). 



4. There is some reason for the belief that T. rhodesiense and T. brucei 

 (Plimmer and Bradford) are one and the same species. 



