126 Sir D. Bruce and others. Trypanosome 



Chart 8.— Curve representing the Distribution, by Percentages, in respect to Length, of 

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

 taken from Dog 2498. This dog was inoculated from Eat 2471, which showed 

 95 per cent, long and slender forms. 



CD 



nj ii 



* ic 



CD 9 



01 



0. 6 



5 

 4- 



3 

 2 

 I 



Microns 



13 



14 



15 



16 



17 



18 



19 



20 



21 



22 



23 



24 



25 



26 



27 



2S 



29 



SO 



31 



32 



33 































































































































































































































































































































































































































































































































































































































































































































































































































In the blood of Eat 2471, Chart 4, the trypanosomes almost all belonged 

 to the long and slender type. Now this is reversed, and the majority are 

 short and stumpy. This goes against the theory that two species are being 

 dealt with in this strain. Passage through the rat favours the production of 

 a long and slender monomorphic type of trypanosome, whereas passage from 

 the rat to the dog at once changes this to a dimorphic type, in which the 

 short and stumpy form the greater number. 



Breadth. — The following table gives the breadth of the trypanosome of 

 Strain III, Dog 2033 :— 



Table XIII. — Measurements of the Breadth of the Trypanosome of 

 Naturally Infected Dog, Strain III, Dog 2033. 



Date. 



Expt. 

 No. 



Animal. 



Number of 

 trypanosomes 

 measured. 



In microns. 



Average 

 breadth. 



Maximum 

 breadth. 



Minimum 

 breadth. 



1913 



203*7 



Eat 



500 



2 -61 , 



4-00 



1 -50 



