i^2 THE SOCIETY FOR THE PRESERVATION OF 



We have now to see whether Mr. Selous's very natural question 

 admits of a satisfactory reply. In the opinion of the present writer 

 it would seem that the solution of the conundrum is not far to seek. 

 Mr. Selous himself admits that when he first made their acquaint- 

 ance, some five- and- thirty years ago, buffaloes far outnumbered 

 all other game in the places of which he writes. The excessive 

 abundance of these slow-moving, water-loving animals, which 

 passed most of their time in precisely the spots that were other- 

 wise adapted to the physical needs of the tsetse, provided so ample 

 a food-supply as to lead to the development of the enormous 

 numbers of the fly testified to by Mr. Selous. It is reasonable to 

 suppose that, prior to the acquisition of firearms by the natives in 

 the closing decades of last century, conditions as regards the big 

 game in the countries between the Zambesi and the Limpopo had 

 undergone little change since the buffalo first made its appearance 

 in South Africa. Having, therefore, for countless ages been 

 supported by buffalo blood, the South African hosts of Glossina 

 morsitans could not readily adapt themselves to that of other 

 animals, and so dwindled in numbers or died out when the 

 buffaloes themselves disappeared. After all, now that the rinder- 

 pest and the advance of civilisation have completed the work of 

 destruction commenced by the natives' guns, the question is 

 chiefly one of historic interest, since there is no reason to imagine 

 that the retention of all the game reserves in Africa will ever lead 

 to the increase of the buffalo to anything approaching its former 

 numbers. 



No Evidence at Present that any Species of Tsetse other 

 THAN Glossina palpalis can Convey the Parasite of Sleep- 

 ing Sickness. 



The possible danger of allowing natives with the parasite of 

 sleeping sickness (Trypanosoma gambiense) in their blood to enter 

 any district at present free from the disease but infested by any 

 species of tsetse-fly, even though Glossina palpalis itself be absent, 

 has been repeatedly urged by the present writer. As an illustra- 

 tion it may be mentioned that the authorities of North-Eastern 

 Rhodesia, where, as has already been stated, Glossina morsitans 

 is abundant, have recently become seriously alarmed lest the terri- 

 tories under their control should be invaded by the malady. Glos- 

 sina morsitans is also widely distributed in North- Western 

 Rhodesia, while just beyond the border, in the Katanga District of 

 the Congo Free State, sleeping sickness is known to be endemic. 

 Here, then, if Glossina morsitans be capable of conveying the 

 disease, there is a * port of entry ' ready to hand. It is, therefore, 

 from the point of view of the present paper, not without import- 

 ance to state that as yet there is no evidence to show that any 

 species of tsetse other than Glossina palpalis can act as a carrier. 



