1911.] Morphology of Trypanosoma gambiense (Dutton). 331 



Comparison of Trypanosoma gambiense with Trypanosoma brucei. 

 On comparing the coloured plate of Trypanosoma ga-m.biense, given at the 

 end of this paper, with that of Trypanosoma brucei* it will be apparent that 

 these two species of trypanosomes resemble each other very closely. There 

 are the same long and slender, intermediate, and short and stumpy forms in 

 both. The micronucleus is small and round, the nucleus oval or round, and 

 the undulating membrane well developed. It may be concluded, then, that 

 it is impossible to separate these two species by shape alone. 



Chart II. — Chart giving Curves representing the Distribution, by Percentages, in respect 

 to Length of 1000 Individuals of Trypanosoma gambiense, Uganda, and Trypanosoma 

 brucei. 



Af/c rons . 



13 





/5 



/6 





/8 



/s 



20 



2/ 



Z2 





24 



25 



26 





28 



29 







32 



33 



34 



;:>:> 



36 



37 



3d 





































































A 



















































p 





N 



























































-\ 









































1 











y 





























































































ft 







/- 













































ft 





V 





















































































































































P 



V 





































































































9 

















































Trypanosoma brucei. 



On comparing the curves representing the distribution by ; 

 respect to length of 1000 individuals of each species, some slight difference 

 can be made out. It is seen that Trypanosoma gambiense lies more to the 

 short end of the curve than Trypanosoma brucei. There are more non- 

 flagellated forms in Trypanosoma gambiense than in Trypanosoma brucei: 

 38 per cent, in the former, 26 per cent, in the latter. It is doubtful, 

 however, if this difference in the curve would always appear. 



In the same way, if the 1000 Trypanosoma gambiense are divided by 

 length into short and stumpy (13 to 21 microns), intermediate (22 to 

 24 microns), and long and slender (25 microns and upwards), as was done in 

 the case of Trypanosoma brucei, the following is the result : — 



* ' Eoy. Soc. Proc.,' B, vol. 83, Plate 2. 



