THE TSETSE PROBLEM IN NORTH MOSSURISE. 381 



would doubtless give much difficulty in some localities in the spring months, but 

 the country generally has water in streams or pools. 



It will be gathered from this that poisoning offers certain difficulties in addition to 

 its possible high cost. It could be put into effect most easily and cheaply round a 

 settled station like Spungabera, where there are also mere patches of wooding to be 

 dealt with ; but here the greatest care would have to be taken to keep all stock from 

 treated areas until all possibility of their obtaining poisoned leaves had passed. 

 The method would be still more useful to occupiers of farms under a settlement 

 .scheme in the fly, for cattle would not yet be present. 



Killing by arsenite, followed by a course of late fires, should be exceedingly 

 effective in removing woodland, and the finality of it, with the fact that it requires 

 vastly less labour than the other radical method, stumping, would be worth the 

 expenditure that a considerable increase in the strength of the poison might entail. 



A local point to be remembered is that my observations were carried out in a year 

 in which bush generally tended to carry leaf in the dry season better than usual 

 owing to the heavy preceding rainy season. Brachystegia wooding has this tendency 

 at all times, except when exposed to relatively rigorous conditions, but if it should 

 be found later that in certain dry seasons the Brachystegia-dommated bush of the 

 " Oblong " generally does become too leafless to harbour brevipaljns, the clearing 

 of the ravine-type thickets might suffice — if at any time in the future the hand- 

 clearing of this area comes to be considered. 



(3). Clearing by judicious ruitive settlement. The first lesson to be drawn from 

 Umzila's results seems to be that we can make a seasonal fly-area safe by broadly 

 (perhaps narrowly) clearing its margin and preventing passage of game. 



In the permanent fly-area and portions of another permanent fly-area that he 

 cleared of fly the result was brought about, apparently, mainly by bush destruction, 

 though game also was greatly reduced. 



It is perhaps a pity that the humane methods of the white man make difficult the 

 wholesale transportation of populations for the elimination of tsetse areas, even in 

 the interests of the population in question. Our methods would be less wasteful 

 than Umzila's. We should begin with a close botanical and oecological study, and 

 we could produce Umzila's result with a half, a quarter or an eighth of the force used 

 by him. 



On a small scale, with such an inducement to settle as the remission of their tax 

 (meaning much to the native, and to the Government a great saving in the cost of 

 clearing by other methods), the plan is still very feasible. When examining the 

 Spungabera problem I was struck by the impression already made in a single season 

 by the native Um^gazaza on a piece of wooding that constitutes one of the special 

 dangers of the place. With a few more Umgazazas settled here this piece of wooding 

 would go — at a small cost to the Company. The soil to be cleared is rich, the natives 

 would raise good crops, and they could dispose of their surplus grain a mile away 

 s,t Spungabera. Other wooding on the Spungabera hill could be treated in the same 

 way. 



The pity is that the cultural operations of our natives do not include the taking 

 out of tree-roots. If, however, they left all stumps standing — and they leave a 

 (737) e2 



