Strain of T. brucei from Zululand. 



503 



Chart 5. — Curve representing the Distribution, by Percentages, in respect to Length, of 

 500 Individuals of the Trypanosome causing Disease in Man in Nyasaland, taken on 

 nine consecutive days from Eat 2300. 



18 

 17 

 16 

 15 

 14 

 13 

 12 

 11 

 10 



§> 9 



S 8 

 c 



O 7 



o ' 



I 6 



5 

 4 

 3 

 2 

 1 



Microns 



13 



14 



15 



16 



17 



18 



19 



20 



21 



22 



23 



24 



25 



26 



27 



28 



29 



30 



31 



32 



33 



34 



35 













































































































































































































































































































































































































































































































































































































































































































































































































































































































The Zululand strain, 1913, has been carried on in horses and cattle for 

 some time in the laboratory at Pretoria, and may have varied somewhat in 

 morphology under these artificial conditions. It will be interesting to see 

 what change, if any, is induced by passage through G. morsitan-s. The three 

 following curves represent first, second and third passages : — ■ 



Chart 6. — Curve representing the Distribution, by Percentages, in respect to Length, of 

 500 Individuals of T. brucei, Zululand Strain, 1913, after first passage through 

 G. morsitans, taken on nine consecutive days from Rat 2006. 



