338 C. F. M. SWYNNERTON. 



Epo7nophorus crypturus, are abundant, and insectivorous species were found sleeping 

 in great numbers in hollow trees of Sterculia triphaca on tbe ant-heaps of vleis 

 frequented by G. morsitans and G. pallidipes, Busbbucks and duikers are more or 

 less common — and hard to exterminate. Tbe little blue duiker {Cephaloplms 

 monticola), more or less abundant in thickets and dense forest, is less hard to reduce 

 by fence-trapping. It has a habit of resting under logs and between tree-buttresses 

 that might bring it into additional contact with the fly. It was one of the animals 

 least liked by my carnivorous mammals. Of yet smaller manamals two species of 

 Tatera came in great numbers to my traps at a spot where male clusters of tnorsitans 

 were present all the time on the grass and females in the wooding (PI. xiv, fig. 2). 

 Lloyd has suggested that nocturnal mammals, including Muridae, are perhaps 

 liable to the attack of tsetses owing to the latter's habit of resting in similar holes. 

 I have myself taken morsitans puparia from holes made by animals in a bank, and 

 noted that brevipalpis and pallidipes rest in holes in trees. Nevertheless, an 

 argument exists against this view in the fact that some of the bats at any rate are 

 very easily disturbed, and the part played by the small nocturnal mammals, including 

 bats, needs far fuller testing than it has received. Species of Arvicanthis, Otomys, 

 Myosorex and Petrodromus are largely diurnal, but their small relative size 

 suggests both their ready perception and intolerance of the fly and their less ready 

 detection by it. 



Dassies or rock-rabbits {Procavia) may be of much use to the fly, but very locally 

 and only in rocky places. I found them in the coarse quartzite rocks that form 

 the crest of the Sitatongas and support Brachystegia ; and I spent many hours 

 with several workers trying to find wet season tsetse puparia in the humus under 

 raised and overhanging rocks, but without success. I searched similarly in the 

 ]\Iaruma forest, frequented by dassies, but Maruma, I judge, in spite of the outbreak 

 of trypanosomiasis there, is seldom if ever reached by the fly. 



The larger Ungulates. 



I have thought it well to give prominence to the evidence favouring the view 

 that the pigs, aided doubtless by the smaller buck and perhaps yet more by the 

 baboons, will continue to support a fly population in parts of north Mossurise even 

 if the larger game is banished. At the same time it goes without saying that the 

 larger the permanent game population the greater wiU be that of the fly ; and I 

 obtained abundant indirect evidence that, as things stand now, the bigger ungulates 

 present in the fly-areas are taking an important part in the feeding of the tsetse. 

 As I shall describe elsewhere, I found numerous batches of puparia — mostly of 

 morsitans, a few of brevipalpis — associated with spots where larger mammals had 

 been lying down. Buflalos were incriminated the most frequently, but Lichtenstein 

 hartebeests, wart-hogs and other species were concerned. 



My finds of pupae in the morsitans area seemed rather to suggest a preference for 

 the buffalo on the part of the fly. I found this definitely asserted by some of the 

 natives and denied by others. My guide in the morsitans area, a very observant 

 native, was particularly convinced of it. Questioned as to a connection between 

 the two animals, he replied that one may find fly where there is no buffalo, but that 

 where there is a choice it foUows the buffalo. " The buck," he said, "are much 



