causing Disease in Man in Nyasaland. 117 



This curve is made up of measurements from 20 specimens of trypano- 

 somes taken from the ox, 20 from the sheep, 260 from the dog, SO from the 

 rabbit, and 660 from the rat. 



■Chart 2. — Curve representing the Distribution, by Percentages, in resiiect to Length, of 

 660 Individuals of the Trypanosome of Naturally Infected Dog, Strain I, Dog 48, 

 taken at random from several rats. 



Micron 5 



13 14- 











19 



ZD 



» 



22 



25 2-1 25 



26 1 27 



28 



29 



3o 3l 



32 



35|34. 





37 



38 



































































































































































































































































































































V 























































































































































I 



II 







































1 













\ 



ii 





































































































































































































































































S 































































— 

































































































1 















i 





17 



16 

 15 

 14- 



a> 15 



■01)12 



■« „ 

 +> 



<u 9 



8 

 i- 



<u 7 

 Q- 6 

 5 

 4 



3 

 2 

 I 



Tins is the curve of a markedly dimorphic type, and may be compared 

 with the Wild-game strain 1 * or with the Wild G-. morsitans strains IV 

 and Y.f The above curve shows the strain as it appeared in the rat in 

 February, 1912, when it was first obtained. The next curve shows the same 

 strain as it appeared in the rat in September, 1912, after it had passed for 

 seven months through a series of eight rats. 



* 'Koy. Soc. Proc.,' B, vol. 87, p. 395 (1913). 

 t Ibid., B, vol. 87, pp. 415 and 417 (1913). 



