101 ;;,,,, 



harboured a trypanosome that might be mistaken f o^ 'that , of, 

 disease in man. On no occasion were trypanosonfes. 

 in buffalos. 



Swynnerton (145), writing with reference to the North Mossurise 

 district, Portuguese East Africa, says : " 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 follows 

 the buffalo. ' The buck/ he said, ' are much more restless under its 

 attentions than the buffalo, the hartebeests especially keeping up their 

 dance when tsetse are about them ; so that the fly can feed more 

 easily on the buffalo ' . . . . Elephants were stated by the natives 

 to be attended by tsetses when the latter are numerous, and I took a 

 male brevipalpis waiting on a much-used elephant path. Roubaud 

 and Bouet (referring to G. longipalpis) are both quoted as speaking 

 of a special association between tsetses and the elephant and 

 hippopotamus." 



Under the heading " Man and the Fly's Preferences," Swynnerton 

 remarks : " Concerning the practical question, ' If other sources of 

 food were eliminated, could the tsetse still keep going with the aid of 

 man ? ' it is certain from the observations of Lloyd, Maugham, Steven- 

 son Hamilton, myself and others that the tsetses would then attack man 

 much more. Tsetses (as I have seen) constantly obtain full feeds from 

 man and escape unscathed and, where the bush comes up to a village, 

 so far from avoiding it, morsitans and pallidipes but not brevipalpis 

 appear to become rather a nuisance." 



With regard to what follows, it is perhaps as well to point out that, 

 in the area dealt with by Swynnerton, nagana rather than sleeping 

 sickness is the all-important problem. 



Writing under the heading " Distributors of the Fly," Swynnerton 

 observes : " Game not only helps (a) to feed the fly, and (b) to provide 

 the trypanosome, but (c) it helps to distribute the fly, carrying it back 

 each summer into the areas from which the fall of leaf had driven it." 

 He further says, after discussing various kinds of game : " I believe, 

 then, that these animals, and the buffalo in particular, are mainly 

 responsible for the annual spread of the fly, and that so far as we are 

 concerned, in and near Mossurise, our main grievance against the game 

 is not so much that it feeds the fly (which would be fed and contami- 

 nated in any case by the pigs) but that it carries it far and wide in the 

 rainy season and so brings it into contact with the cattle." However, 

 after considering the effect of the rinderpest outbreak in 1896 upon the 

 game and upon G. morsitans and G. pallidipes in North Mossurise, 

 Swynnerton comes to the conclusion that : " The failure of the 

 rinderpest to destroy the fly here to any appreciable extent .... 

 tells also against the hope that we may exterminate the fly in the 

 Mossurise district by destroying the bigger game only." 



Later in the same paper, in a section headed " Game Destruction," 

 Swynnerton writes : " In view of the evidence I have already 

 alluded to, we are bound to keep an open mind with regard to the 

 possibility that even G. morsitans might survive the destruction of all 

 large mammalian life. Yet the fact that under present conditions 

 game-paths are the regular rendezvous of the sexes, and that the 

 connection with game appears generally to be an essential point in 



