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■Trypanosomas found in Wild Glossina morsitans and Wild Game 

 in the " Fly- Belt " of the Upper Shire Valley. 



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

 Hamerton, D.S.O., and Captain D. P. "Watson, RA.M.C. ; and Lady 

 Bruce, RRC. (Scientific Commission of the Royal Society, Nyasaland, 

 1912-14.) 



(Received April 7, — Read June 18, 1914.) 

 Introduction. 



In June, 1913, one of the members of the Commission went to the 

 Liwonde district to identify ' and isolate the various species of trypanosomes 

 infecting the " fly " and wild game in the " fly-belt " which extends along the 

 Upper Shire River valley from Lake Pamalombe to the Murchison cataracts. 

 This " fly-area " is, roughly speaking, 100 miles south of Kasu and the 

 " Proclaimed Area." It is separated from the extensive " fly-area " of the 

 plains on the west shore of Lake ISTyasa, of which the " Proclaimed Area " 

 forms a part, by a range of hills and high plateaux where the " fly " is 

 absent, although there is nothing to prevent trypanosome-infected wild 

 animals wandering from one " fly-belt " into the other. 



The valley of the Upper Shire is thickly populated, and the "fly-area" is 

 crossed by two of the most frequented roads in Nyasaland, the grand trunk 

 road running from Zomba to the north and the main road from Liwonde to 

 Fort Johnston. Although thickly populated, human trypanosome disease, 

 though probably existing, has not yet been discovered in this district.* 

 The natives, however, can keep no cattle, and their goats and dogs are 

 constantly destroyed by trypanosome diseases, so that they have to con- 

 tinually import these animals from the highlands. 



Game is very abundant in this district, particularly in the dry season, 

 when herds of eland, koodoo, waterbuck, and impala concentrate in the 

 vicinity of the river. In the wet season elephant and buffalo wandering 

 about the country frequently remain for many weeks in the impenetrable 

 thickets and swampy " danibos " along the river banks. A characteristic 

 feature of the flora of this district is the extensive forests of " sanya " trees, 

 open forests of medium-sized trees, devoid of undergrowth, but carpeted 

 with short wiry grass. Large herds of impala are always to be found in 

 these forests, and. tsetse flies are everywhere, being particularly numerous 



* Since this was written cases of trypanosome disease in man have been found. 



