GAME ANIMALS TO DISEASE IN AFEICA 17 
more dependent upon the blood of mammals for their existence 
than are mosquitoes, and goes on to say, ‘ Unless I am right in 
this opinion I am at a loss to understand how the enormous 
numbers of tsetse fly which are found in some districts can 
exist,, as in many of these areas game is either extremely 
scarce or almost non-existent. In Nyasaland it is distinctly 
noticeable that many of the fly areas are almost destitute of 
game, whereas, on the other hand, some parts of the country 
where game is most abundant, such as the valley of the Eukuru 
Eiver, are entirely free from tsetse ; and in this locality, as 
in others, buffaloes are fairly numerous ’ (‘ Sleeping Sickness 
Bulletin,’ No. 22, p. 404). 
In 1908 Major Hamilton, the Game Warden of the Transvaal 
game reserves, and the British Consul at Louren^o Marques, 
made a journey from Port Amelia to Nyasaland. For a stretch 
of about ninety miles large numbers of tsetse fly were found, 
but no big game and very little small game. There was thick 
bush and very little water. After they crossed the Lugenda 
river, game, including buffalo, became very plentiful, but there 
was no tsetse fly. This statement is the more worthy of belief 
because Major Hamilton is a careful observer and a keen 
hunter (‘ Sleeping Sickness Bulletin,’ No. 28, p. 270, and 
Bulletin No. 80, pp. 862-68). 
Similar cases are to be met with in British East Africa. 
In some parts of the dry arid bush country in the neighbourhood 
of Kibwezi numbers of tsetse flies are to be found ; yet game 
animals of any kind are scarce, with the exception of the tiny 
dik-dik antelope. 
It will also be remembered that Mr. F. C. Selous has 
pointed out cases in South Africa where the range of tsetse 
flies is quite sharply defined, although beyond the fly belt 
the vegetation appears identical with that inside the belt, 
and that game abounds both inside and outside of the 
fly area. 
I have myself (E. B. W.) witnessed this phenomenon in 
Bechuanaland in South Africa, and it is a mystery without 
explanation, unless upon Mr. Selous’ theory that the presence 
or absence of buffalo is the determining factor. I hesitate to 
accept this explanation, and am more inclined to the opinion 
Vol. IV.— No 7. c 
