THE WILD FAUNA OP THE EMPIEE 11 



THE DEPENDENCE OR NON-DEPENDENCE OF TSETSE- 

 FLIES UPON BIG GAME, ^YITH SPECIAL REFER- 

 ENCE TO THE SPECIES OF TSETSE KNOWN AS 

 GLOSSINA PA LP A LIS AND SLEEPING SICKNESS. 



By Ernest E. Austen, F.Z.S. 

 (Author of 'A Monograph of the Tsetse-flies,' etc.) 



Whatever view the reader may hold upon the subject of this 

 paper, no one can fail to agree with the recent pronouncement by 

 a leading English scientific journal that sleeping sickness is to-day 

 ' the most burning problem of European colonisation in Equatorial 

 iVfrica.'^ Not only has the dread disease, which has hitherto 

 baffled all endeavours to hud a certain cure on the part of the ablest 

 experts in tropical medicine among several European nations, 

 within the last seven years claimed many hundreds of thousands of 

 victims among native races for whose welfare we in common with 

 others have made ourselves responsible, but the rapid spread of 

 the malady itself and its extension into fresh districts are already 

 threatening the development of important commercial enterprises, 

 which depend for their prosperity upon the regular supply of 

 native labour. Serious as are the losses and impediments to settle- 

 ment and progress due to tsetse-lly disease in domestic animals, 

 these are as nothing when compared wdth the threatened depopu- 

 lation of large tracts of the African continent. Furthermore, 

 although it was at one time believed that white men were not liable 

 to contract the disease, it has been proved by a number of sad 

 examples that no European resident in an area infected by sleeping 

 sickness can consider himself altogether safe. 



While the accuracy of the foregoing statements must be 

 generally admitted, it is equally true that, at the present time, the 

 most serious menace to the continued existence of big game and 

 game reserves in various parts of Africa is the idea, apparently 

 held by many people, that to protect game is to preserve tsetse- 

 flies, and so increase the risk of the spread of sleeping sickness ; 

 since, so far as is at present known, the minute living parasite that 

 is the cause of the disease is carried from man to man solely by 

 the bite of a particular species or kind of tsetse-fly, termed by 

 naturahsts Glossina palpalis. In other words, it is maintained 

 that tsetse-flies subsist exclusively upon the blood of big game, 

 and that if the latter were utterly destroyed tsetse-flies themselves 



1 Nature, November 14, 1907, p. 36. 



