12 J. W. SCOTT MACFIE — THE DISTKIBUTION OF GLOSSINA 



In many parts there is thick bush, and the tsetse-flies are very numerous, either 

 of which circumstances might deter the Fulani from leading their herds here to 

 graze ; moreover, the more easterly districts would be reached most naturally 

 from the north, when a wide stretch of country infested by G. submorsitans 

 would have to be crossed. There is no doubt, however, about the fact that 

 infection with T. brucei can be incurred in this division, and the experience of 

 successive Residents has been that the ponies they use on tour in the eastern 

 districts almost invariably die. Game is fairly plentiful in certain parts of the 

 division, as it is in the eastern or Patigi division, whereas it is scarce in the 

 western division ; and it is possible, therefore, that trypanosomiasis may be 

 maintained, in this instance, by infected game, and transmitted from them to any 

 horses or cattle that venture into the neighbourhood. 



Fig. 4. — Plan of Offa, (A) being the tsetse-haunt. 



At Offa itself, which is not only a large native town, but also an important 

 station of the railway, only G. palpalis was found. On the western side of 

 the line lies the native town, and on the eastern the residential quarters for 

 Europeans ; on the latter side the ground rises gently and at the foot of the 

 slope a small stream runs northwards in a direction parallel to the railway. 

 The sloping ground is divided in two places by narrow valleys, on the ridge 

 between which the Residency stands, and but a little way to the south lies an 

 isolated patch of marshy ground from which originates a small stream. When 

 I visited Offa, in April 1912, this patch of marshy ground (marked A on the 

 plan) was covered with trees and undergrowth, and was found to be the haunt 

 of abundant tsetse-flies (PI. Ill, fig. 1). 



The rest of the station was sparsely wooded and apparently free from these 

 insects ; but as I was assured that during the rains they were sometimes seen 

 even in the bungalows, I concluded that during the dry season the swamp formed 



