Trypanosome causing Disease in Man in Nyasaland. 191 



On comparing the curves from the 10 strains it cannot be said that the 

 passage from dog to rat, or from monkey to rat, or direct from man to rat, 

 has had any marked influence on the character of the curve. But in these 

 cases only a single monkey or dog intervened. 



In the case of Strain I, Mkanyanga, the trypanosomes were taken at 

 random from several species of animals ;* 600 trypanosomes from four 

 different rats were measured. The passages are as follows: — (1) Man, 

 monkey, Eat 38 ; (2) man, dog, rat, rat, Eat 37 ; (3) man, monkey, guinea- 

 pig, monkey, Eat 236 ; (4) man, monkey, guinea-pig, monkey, Eat 235. 



VI. Morphology of Strain VI, Manakumpara. 

 The following Table gives the average length of this trypanosome as found 

 in the white rat, 500 trypanosomes in all, and also the longest and 

 shortest : — 



Table II. — Measurements of the Length of the Trypanosome of Strain VI, 



Manakumpara. 



Date. 



Expt. 

 No. 



Animal. 



Method of 

 fixing. 



Method of 

 staining. 



Average 

 length. 



In microns. 



Maximum 

 length. 



Minimum 

 length. 



1913. 

















June 30 ... 



2239 



Eat 



Osmic acid 



Giemsa 



21 -4 



27 -0 



18 -0 



„ 30 ... 



2239 





>t 





21 -6 



29 



18 -0 



;, 30 ... 



2239 





" 



)» 



22 1 



27 -0 



20 -0 



July 1 ... 



2239 





) J 





19 -0 



23 



17 -0 



1 ... 



2239 







>> 



18 -6 



23 -0 



15 -0 



„ 1 ... 



2239 









18-6 



23 -0 



16 -0 



2 ... 



2239 









19 -8 



22 -0 



17-0 



2 ... 



2239 









20-6 



25 -0 



17 -0 



„ 2 ... 



2239 









19 -3 



21 -0 



17 -0 



„ 3 ... 



2239 









21 1 



27 -0 



17 -0 



„ 3 ... 



2239 









21 -8 



26 



17-0 



„ 3 ... 



2239 





>J 



Ti 



22 6 



30 



17 -0 



„ 4 ... 



2239 





>» 





23 -0 



26 -0 



17 -0 



4 ... 



2239 









23 



29 -0 



18 -0 





2239 









23 



28 -0 



19 -0 



:: i z 



2239 







J) 



22 -4 



28 -0 



17 -0 



„ 5 ... 



2239 









21 -8 



30 -0 



17-0 



„ 5 ... 



2239 







■) 



23 8 



29 -0 



18-0 



„ 7 ... 



2239 







)) 



23 -5 



28 -0 



21 



M 7 ... 



2239 





J* 





22 -9 



30 -0 



17-0 



„ 7 ... 



2239 









24 -5 



32 -0 



19 



„ 8 ... 



2239 





)' 



)> 



23 



28 -0 



19 -0 



„ 8 ... 



2239 









22 -6 



29 



17 -0 



8 ... 



2239 









21-2 



27 -0 



15 



j ;, 9.... 



2239 









20 -6 



26 -0 



15 



1 1 1 







21 -7 



32 -0 



15 -0 



* ' Roy. Soc. Proc.,' B, vol. 85, p. 427 (1912). 



Q 2 



