202 



Sir I). Bruce and others. Trypanosome 



an infected rat was diluted with normal saline solution until a volume 

 one-sixteenth of an inch in length of a fine capillary tube was found to contain 

 a single trypanosome. This was then inoculated into a rat. Six experiments 

 were made, three of which were successful. In each case the long and slender 

 type of trypanosome was isolated and injected. 



As will be seen from the following curves, from the single long and slender 

 type, short and stumpy, intermediate, and long and slender forms resulted. 

 Among the short and stumpy there was a large percentage of the blunt-ended 

 posterior-nucleated forms, which are a feature of this species of trypanosome. 



From these three experiments, then, it may be concluded that in the 

 dimorphic trypanosome causing disease in man in Nyasaland, a single species 

 is being dealt with. 



Chart 7. — Curve representing the Distribution, by Percentages, in respect to Length, of 

 500 Individuals of the Trypanosome of Strain X, Dongolosi, taken on nine consecu- 

 tive days from Eat 2493, which had been infected by a single trypanosome of the 

 long and slender type. 



c r o n s. 



9 20|2I |22|Z3|Z4 ?5 , 2fe|2 7| 2b \ 23 [ 30 | 31 \}2 \ 33 | 3« | 35 | 36 | 37 36 



