1913.] causing Disease in Man in Xyasaland. 



421 



Chart 7. — Curves representing the Distribution, by Percentages, of 3600 Individuals of 

 the Trypanosome of the Human Strains, 2500 of the Wild-game Strains, and 2500 of 

 the Wild Glossina morsitans Strains. 



Microns 



13 



14 



15 |l6 



7 



IS 



19 





V 



2Z 





25 | 26 j Zf j 20 



2 3 



jo|ji 



JZ 



at 



1 l 



S7 































































































































M 



fild Game Strain. 

 • G. Morsitans •• 

 uman Strain. 























































\\ 

























































H 



\ 

















































/ 





V 







"0. 

































































































y 









'o 





















































































/ 







/ 















©-. 



"CI 































i 









































1 











i 





p 











V 



V 



























































J 



























1 





























■*cv 

























I 



















































id 





























5ft 











17 





16 





15 





w- 





15 



n 



I- 



<o 



II 



Oil 





<i 



10 



•P 



9 



c 





0) 



8 



U 



7 







0) 



6 



Q_ 







5 





4 





3 





2 



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

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

 and Wild Glossina morsitans Strains. 



Date. 



Strain. 



Average. 



Percentages. 

 Maximum. 



Minimum. 



1912 





21 -1 



52 -0 



2 



1912 





26 -2 



33 -4 



8-4 



1912 



Wild G. morsitans 



12 -5 



28 -9 



4-2 



Conclusions. 



1. The five Wild Glossina morsitans strains resemble each other closely, and 

 all belong to the same species of trypanosome. 



2. The Wild Glossina morsitans strain, the Human strain, and the Wild- 

 game strain, belong to the same species. 



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



4. It is probable that T. rhodesiense and T. brueei (Plimmer and Bradford) 

 are identical. 



