14 CONDITIONS IN SOUTH AFRICA. 



would natui-ally avail themselves of the opportunity of obtaining- 

 a meal of blood afforded by the passage of men and other 

 animals through their haunts. Whether reproduction is im- 

 possible without such a meal, as appears to be the case as 

 regards certain species of mosquitoes although apparently not 

 the rule, remains to be proved. If, however, Tsetse which have 

 not fed on blood are incapable of reproduction, it follows that 

 they would become extinct in one generation after this food 

 supply ceased. 



Our knowledge of the distribution of the various species of 

 Glossina is as yet very scanty, but it is possible that the species 

 concerned in Mr. Jackson's statement with regard to the Fly- 

 belts in East Africa [127] referred to above, is Gl. 2^Midipes,, 

 Austen, rather than Gl. morsitans, Westw. If this is so, the 

 discrepancy between Mr. Jackson's testimony and the consensus 

 of opinion as to the close association between Gl. morsitans and 

 big game might be due to a difference in the habits of the two 

 species. But the more probable explanation would seem to be' 

 that, as already mentioned in a previous section, the Tsetse will 

 not live on open grassy plains, even when teeming with game.* 

 It may be added that in the subsequent letter to Lord Lans- 

 downe, Mr. Jackson appears at the outset to admit the con- 

 nection, even in East Africa, between the Tsetse and game ; 

 although, as already shown, he afterwards advances the view 

 that " the Tsetse is .... only a blood-sucker by predilection." 



Three species of Tsetse f are known to occur in East Africa, 

 and more precise observations are necessary to decide the 

 relationship between each of them and the game of that region; 

 With regard to South Africa, however, there can be no question 

 that the extermination of big game has been followed or accom^ 

 panied by the disappearance of the Tsetse from many localities 

 in which it formerly abounded. That this would ultimately be 

 the case was suggested long ago by Livingstone [21 ], and the 

 assertion has been repeated by many subsequent writers. J Ample 

 proof of the correctness of the forecast is furnished by what has 

 taken place in. the more southern, portions of the Transvaal [105, 

 112]. In South Africa, according to the testimony of various 



* In East Africa, according to Mr. Jackson [127], " the open, undulating; 

 gi'assy plains of the Masai country, and other places of a like nature, are 

 the headquarters of by far the greatest quantity and variety of game, and 

 are entirely free from the Ts6ts6-tly, . . . ." 



t Glossina inorsitans, W'estvr., Gl. pallidipcs, Austen, -and Gl. fiisca. 

 Walker. 



T C/. 55, 5^, 112, 128, 135, 153." ^ ■ 



