1912.] 



Causing Disease in Man in Nyasaland. 



433 



Chart 3. — Chart giving Curves representing the Distribution, by Percentages, in respect 

 to Length, of 1000 Individuals of T. rhodesiense, and 1220 Individuals of the 

 Trypanosorae of the Human Trypanosome Disease of Nyasaland. 



12 13 14 15 16 11 iS 19 20 21 22|23|24|25|26|27 28 29 30 31 32 33 34 35 36 3? 38 



Trypanosoma rhodesiense looo . 



Trypa.zwGO?ne of Afyasaland /xzo. 



Conclusions. 



1. The trypanosome of the human trypanosome disease of Nyasaland is 

 T. rhodesiense (Stephens and Fantham). 



2. This is a distinct species, nearly related to T. brucei and T. gambiense, 

 but more closely resembling the former than the latter. 



3. From this it follows that the human trypanosome disease of North-east 

 PJiodesia and Nyasaland is not the disease known as Sleeping Sickness in 

 Uganda and the West Coast of Africa. 



4. The native name " Kaodzera " might be used for this new disease to 

 distinguish it from the older known Sleeping Sickness. 



DESCRIPTION OF PLATES. 

 Plate 11. 



Trypanosoma rhodesiense, posterior nuclear and blunt, hippo-headed forms found 



commonly in this species, x 2000. 

 Figs. 1, 2, and 3. Intermediate forms with blunt posterior extremities. 

 Figs. 4, 5, 7, 8, 9, 10, and 11. Posterior nuclear forms. 

 Fig. 6. Nucleus near anterior extremity. 

 Figs. 12 and 13. Posterior nuclear intermediate forms. 



Plate 12. 



Trypanosoma rhodesiense, Nyasaland, 1912, stained Giemsa. x 2000. 

 Figs. 1 — 5. Long and slender forms. 

 Figs. 6 — 10. Intermediate forms. 

 Figs. 11 — 16. Short and stumpy forms. 



2 H 2 



