98 



to compel the flies to feed, in so far as they do not do so already, 

 upon small mammals, such as rodents and the like, and upon birds, 

 reptiles, batrachians, etc. According to M. Trouessart, of the Paris- 

 Museum, Tsetse would perhaps diminish in number, but would not 

 become extinct, and even though the keeping of domestic animals 

 in the district concerned were to cease for ten years, at the end of this- 

 period the deadly flies would again begin to swarm and to produce 

 the same results as before. 



Moreover, many of those who have had great practical experience 

 of Tsetse-flies are by no means of the opinion that the distribution 

 of the insects is governed by the presence of big game. We shall 

 here confine ourselves to quoting the conclusions of papers published 

 in recent years by certain observers, including Sir Alfred Sharpe,, 

 Major J. Stevenson Hamilton, Dr. S. A. Neave and Mr. C. F. M. Swyn- 

 nerton, all of whom are entitled to speak with authority upon the 

 subject. 



During six or eight years Sir Alfred Sharpe, K.C.M.G., C.B., formerly 

 Governor of the Nyasaland Protectorate, made very careful observa- 

 tions in the areas infested by Glossina morsitans in Nyasaland, North- 

 Eastern Rhodesia, and the portions of Tanganyika Territory and Portu- 

 guese South-East Africa bordering on Lake Nyasa, all of which regions 

 he frequently traversed. In a paper (137) which appeared some 

 eleven years ago he writes : " My own opinion, which I have expressed 

 on various occasions before now, is that the existence of wild game has 

 very little, if anything, to do with the existence of any species of tsetse- 

 fly. At the time when rinderpest visited Nyasaland, there was a 

 noticeable decrease in the quantity of big game in some of the districts 

 where tsetse-fly exists, especially as regards buffalo, but I have never 

 noticed that this had any effect on the presence of Glossina." Sir 

 Alfred Sharpe does not share the opinion of those who think that 

 G. morsitans is " spreading," and he considers that fly areas do not 

 " alter their limits to any appreciable extent." In concluding his 

 remarks, he observes : " There are various causes for fly being now 

 more noticed : more attention than formerly has been called to the 

 subject ; cattle are now kept by natives in districts where formerly 

 owing to wars and raids, there were none ; large native settlements 

 have altered their locations (notably at Fort Johnston, at the south 

 end of Lake Nyasa), and as the old clearings grew up fly appeared. 

 Increased transport by ox-wagons has revealed the existence of fly 

 also in places where it was not noticed before." 



Major J. Stevenson Hamilton, Warden, Transvaal Government Game 

 Reserves, in a paper on "The Relation between Game and Tsetse- 

 Flies" (62), writes: "The theory that the larger wild mammals, 

 commonly called 'big game/ are solely and entirely responsible for 

 the presence of tsetse-flies has become so firmly fixed in the mind of 

 the average ' man in the street ' in South Africa, that no amount of 

 contrary argument or even proof, were such forthcoming, could ever 

 have much effect in altering his opinion. The newcomer quickly 

 assimilates the same idea, and after a time begins to voice it as asser- 

 tively as his mentor. It is thus most difficult to obtain really reliable 

 data. An investigator, beginning an enquiry with an open mind, 

 finds himself flooded with such a mass of apparently well-substantiated 

 statements, provided by experienced and obviously sincere persons, 

 that he can with difficulty keep his mind free from a certain amount of 

 bias." Nevertheless, from " personal experience," gained during a 

 journey through the northern part of Portuguese East Africa in. 



