1912.] 



Causing Disease in Man in Nyasaland. 



- 2i 



Breadth. — The long and slender average l - 7 microns in breadth, the inter- 

 mediate 2-1, and the short and stumpy 2*9. This measurement was made 

 across the broadest part in 100 of each of the three varieties of this 

 trypanosome. 



Shape. — The long and slender are very similar in appearance to T. brucei 

 and T. gambiense, but the intermediate differ to some extent in that the 

 posterior extremity seems often to be more elongated than in the other two 

 species, and blunter (Plate 11, figs. 1, 2, and 3 ; Plate 12, figs. 6, 8, and 9). 

 The short and stumpy are also characterised by blunter posterior extremities, 

 often suggesting the appearance of a hippopotamus head (Plate 11, figs. 8 

 and 9). On comparing these plates with those of T. brucei and T. gambiense 

 this difference will readily be seen. 



Contents of Cell. — In well-stained films the protoplasm of many of the 

 trypanosomes shows granules, especially in the anterior portion of the cell. 



Table V. — Percentage of Posterior Nuclear Porms found among the Short and 



Stumpy Varieties of the Trypanosome of the Human Trypanosome 

 Disease of Nyasaland. 



Date. 



Expt. No. 



Animal. 



Percentage of short and 

 stumpy forms. 



Proportion to 

 all forms per 1000. 



1912. 











Mar. 1 



233 



Monkey 



7 



17 



4 



233 





10 



25 



„ 14 



Feb. 23 



233 





6 



15 



234 





21 r . 



52 



Mar. 1 



234 





1 



2 



Feb. 29 



14 



Dog 



7 



17 



„ 26 



157 





16 



40 



„ 29 



243 





41 



102 



„ 29 

 Mar. 18 



13 



Gruinea-pig 



6 



15 



13 



8 



20 



„ 14 



165 





7 



17 



„ 18 

 Feb. 29 



165 





36 



90 



166 





17 



42 



Mar. 18 



239 





36 



90 



Feb. 22 

 „ 23 



235 

 235 



Eat 



7 



22 



17 

 55 



„ 27 

 „ 28 



235 

 235 





38 

 41' 



95 

 102 



„ 29 



235 





39 



97 



Mar. 1 



235 





51 



127 



» 4 



235 





29 



72 



>, 5 

 „ 6 



235 

 235 





30 



75 

 90 



„ v 



„ 8 



235 

 235 





30 

 38 



75 

 95 



„ 11 



235 





39 



97 



„ 13 

 Feb. 27 



., 29, 



235 





45 



112 



236 

 236 





24 

 32 



60 

 80 



Mar. 1 



236 





46 



115 



