Plasmodium cephalophi. 



45 



Conclusions. 



1. The trypanosome causing disease in man in Nyasaland is fatal to goats, 

 sheep, dogs, and the smaller laboratory animals, killing them, without 

 exception, in a few weeks. It is less virulent to cattle, many of which 

 evidently escape. 



2. No difference in virulence can be made out in these five Human strains. 



3. It is not satisfactorily proved yet to what species this trypanosome 

 belongs, but the Commission at present leans to the opinion that it is 

 T. brucei (Plimmer and Bradford). 



Plasmodium cephalophi, sp. nov. 



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

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



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



(Eeceived May 26 ,— Eead June 12, 1913.) 



[Plates 4 and 5.] 



It would appear from a perusal of the available literature that malaria of 

 antelopes has not hitherto been described ; it is therefore proposed to place 

 on record the discovery of a plasmodium found in the blood of two of these 

 animals in Nyasaland. 



This parasite was first seen in the blood of a young duiker (Cephalophus 

 grimmi), and was subsequently discovered in another young animal of the 

 same species. Both these small antelope were at the time in captivity, and 

 it was therefore possible to examine slides from day to day, and by this 

 means a large number of parasites at various stages of development were 

 observed, and some of these are figured in Plates 4 and 5. 



The acute attack in one antelope, however, only lasted four days, and the 

 parasites soon disappeared entirely from the peripheral blood, whereas in the 

 other only a few parasites were seen, and these have persisted in the blood 

 for some months. 



The parasites resemble somewhat Plasmodium malarias of man, in that the 

 gametocytes are circular and the schizonts have from eight to twelve 

 merozoites ; also amoeboid movement is sluggish. They differ, however, in 

 the marked enlargement and paleness of the red cell and in the arrangement 



