ANIMAL INDUSTRY 44 1 



against diseases such as rinderpest and east coast fever are under- 

 taken, an outlet for surplus stock must be ensured in every area, 

 and that veterinary science in Africa has been attempting to cut its 

 own throat, so to speak, by controlling disease at too early a stage. 

 That such a non possumus attitude is scientifically untenable seems 

 proved by the following considerations. It is probably true that 

 in a state of nature, animal disease to some extent counteracts 

 overgrazing, but it is only one among many factors, such as starva- 

 tion and attacks by carnivorous animals, which contribute to keep 

 down the increase of stock. Moreover, as a means of control, 

 disease is clumsy and indiscriminate. It does not necessarily kill, 

 but often only weakens, and efficiency is impossible in a diseased 

 community where overheads remain the same, while production 

 is reduced. The native's preference of quantity to quality is prob- 

 ably a direct consequence of the uncertainty which has in the past 

 been associated with animal life in Africa, and cannot be altered 

 by teaching the native to place quality before quantity, until he is 

 given a sense of security by protection from the risk of decimation 

 by disease. 



It is possible to go still further than this, and claim that disease 

 is not the natural cure for overgrazing, but is actually an important, 

 perhaps the most important, cause of the trouble. This is the view 

 held by Captain Hornby (1936), who points out that the over- 

 stocking question is acute in Tanganyika because four-fifths of the 

 stock population are concentrated on one-ninth of the land, 

 almost entirely owing to the ravages of disease. '. . . The native 

 husbandman is only capable of maintaining large flocks and herds 

 on land, the vegetation of which is indicative of arid or sub-arid 

 conditions, since land with persistent vegetation favours ticks, flies, 

 and worms, against the ravages of which the unaided native is 

 helpless. Therefore, because overstocking inevitably tends to pro- 

 duce aridity and to reduce the incidence of parasitic disease, 

 native stock-owners favour it, preferring seasonal losses from star- 

 vation, which they can understand, to continual and greater 

 losses from disease, the nature of which is beyond their compre- 

 hension' (Hornby 1936, p. 355). The deduction from this 

 argument is that the redistribution of population and stock may 

 be accomplished and hence the problem of overstocking solved 



