126 B. MOISEE — DESCKIPTION ()1-^ HAUNTS OF GLOSSINA TACHINOIDES, &C. 



On investigating the " bush " some 400 or 500 yards on either side of the 

 river, no flies were seen at all, and at one or two small villages, situated a mile or 

 so from the river, I was informed that the Hies never appear there. So that 

 apparently the " belt " is confined to the immediate course of the river Hawal, 

 and as far as I was able to ascertain, extends for at least ten miles along the 

 river, the tsetses living at particular spots only, the intervening spaces being 

 normally free from them, except when the flies follow human beings who traverse 

 these areas. 



These two isolated and comparatively restricted fiy-belts would seem to afford 

 very favourable conditions for studying the factors which determine the distribu- 

 tion of these particular species of Glossina ; but the investigation would 

 necessitate a residence of at least some months in the vicinity. 



The fact that the flies are so cviriously localised even within the limits of the 

 fly-belt may prove of some impoi'tance ; and it might be possible to ascertain 

 what it is that influences them to congregate, as they do, about certain particular 

 bushes. 



