In the foregoing pages the following tentative views have been put forward in the hope that they may receive either confirmation or criticism from other investigators : (1). The latter part of the dry season is probably, in general, the most favourable portion of the year to the fly. (2). The later the onset of the rains the greater the capacity for increase. (3). Seasons of unusually heavy rainfall are inimical, at least in certain areas. (4).A series of years of lew rainfall is favourable. (5).Regions where the fly commonly attains the greatest concentration of numbers are the regions where it is most liable to be reduced or to die out,namely, parts of the infested areas where first-grade foci predominate. (6).In Southern Khodesia the passage of grass fires has, as a rule, no appreciable effect on the numbers of the fly. (7).Mopani belts are probably of considerable value to the fly in providing limited areas attractive to game in the wet season, where the grass remains short; they possibly also afford a convenient refuge from grass fires in the dry season. (8).The fly does not migrate under the stimulus of hunger or in company with game. (9).The fly as a whole does not follow game about infested areas. (10).The maximum distance at which a hungry fly readily detects its hosts is a short one, possibly less than 100 yards. (11).The maximum following distance of the females remains to be determined ; the writer is not yet convinced that the females seek animals and humanbeings only for the purpose of feeding, though this appears probable.