48 



Trypanosomes of the Domestic Animals in Nyasaland. I. Try- 

 panosoma simice, sp. nov. Part II. — The Susceptibility of 

 Various Animals to T. simice. 



By Surgeon-General Sir David Bruce, C.B., F.R.S., A.M.S. ; Majors David 

 Harvey and A. E. Hamerton, D.S.O., B.A.M.C. ; and Lady Bruce, 

 B.K.C. 



(Scientific Commission of the Royal Society, Nyasaland, 1913.) 

 (Received June 2, — Read June 12, 1913.) 

 Introduction. 



In a previous paper* the morphology of this interesting species of trypano- 

 some was described, and it is now proposed to give an account of its action 

 on animals. 



One of the first interesting points to be noted about this species is that, 

 as far as is known, the warthog {Phacochcerus cetheopicus) is the only animal 

 among the wild game of this district which harbours it.t It is probable 

 that it will also be found in the blood of the bush-pig, but not a single 

 specimen of this animal has as yet been obtained by the Commission. The 

 warthog is numerous in the low country in this neighbourhood, which 

 accounts for the large number of tsetse flies found to be infected with 

 Trypanosoma simice.% 



It is to be regretted that this species was not named after the warthog 

 instead of the monkey, but at the time the name Simice was taken the Com- 

 mission was ignorant of the close connection which exists between the former 

 animal and this parasite. 



Another interesting feature in regard to this trypanosome is the virulence 

 it displays towards monkeys and the domestic pig, killing these animals in 

 an incredibly short period of time, whereas it is harmless to oxen, antelope, 

 dogs, and the smaller experimental animals. Curiously enough, this 

 trypanosome also infects goats and sheep, although oxen and antelope escape.. 



The rapidity with which the virulence of T. simice becomes modified is 



also remarkable. When a cage containing wild Glossina morsitans is placed. 



on a monkey and a goat, both animals take the disease, and the monkey in 



such an acute form that the average duration of life is only a few days. But 



if it is attempted to pass T. simice from an infected goat to a healthy monkey 



by the inoculation of the goat's blood, the experiment usually fails, showing 



* ' Roy. Soc. Proc.,' 1912, B, vol. 85, pp. 477-481. 



t Ibid., " Trypanosomes found in Blood of Wild Animals." 



% Ibid., " Infectivity of Glossina morsitans in Nyasaland." 



