The Food of G. morsitans. 



41 



waterbuck. T. brucei vel rhodesiense was found in only one animal out of the 

 sixteen, T. simice in none, and T. caprce in three. 



Conclusions. 



1. The trypanosomes found in the wild G. morsitans and wild game of the 

 Upper Shire* " fly-area " are identical with those found 100 miles farther 

 north in the Proclaimed Area. 



2. The trypanosome causing disease in man in jSTyasaland — T. brucei vel 

 rhodesiense— is frequently met with, so that it is probable cases of this form 

 of sleeping sickness will be found among the natives of this district. 



The Food of Glossina morsitans. 



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

 Hamerton, D.S.O., and Captain D. P. Watson, B.A.M.C. ; and Lady 

 Bruce, B.B.C. (Scientific Commission of the Koyal Society, Nyasaland, 

 1912-14.) 



(Beceived April 7, — Bead June 18, 1914.) 



Five hundred flies, freshly caught in the Proclaimed Area, were killed by 

 chloroform and the gut of each was roughly dissected out, smeared on a slide, 

 fixed by osmic vapour and alcohol, and subsequently stained by Giemsa. The 

 flies were all caught in the bush, away from the paths, the fly-boys proceeding 

 in single file and catching the flies with gauze nets as they circled round, or 

 settled on the boys or the grass. 



The proportion of male flies to females caught was roughly two to one. 

 But only 30 females were used in the present experiment, the majority being 

 sent to the breeding-station at Chunzi. 



Of the 500 flies examined, 288, or 57'6 per cent., were found to contain 

 mammalian blood in a recognisable state. No measurements were made 

 of corpuscles, which in most cases were much altered by the digestive 

 processes, but the small type of cell appeared to predominate, such as 

 occurs in the hartebeeste, waterbuck, and other antelope. 



In only three cases were nucleated red corpuscles found, and in two of 

 these there was only a small proportion of nucleated blood mixed with a 

 large amount of mammalian. In the third case the blood was all nucleated. 

 Thus, of those flies which contained recognisable blood, only TO per cent. 



