PRESIDENTIAL ADUEESS SECTIOX D. 69 



that progress would be slow. But if we accept the evidence of 

 ancient workings tor the recovery of gold and of the ruins 

 still in existence in the area where we have the pleasure of 

 holding our meeting to-da}', the attacking forces overcame 

 obstacles, jienetrated far inland and luade determined efforts 

 to master the countrj^ Why did they not persist ? The deserts, 

 the swamps, the mountains and the rivers were gradually 

 crossed and recrossed, but the " deadh' climate " remained 

 inscrutable till the jjrogress of science at last shed a flood of 

 light on the whole matter by proving that its deadliness was 

 not due to conditions in general, but to the presence of certain 

 definite destructive agencies. In the light of our present 

 knowledge there is no reason to doubt that these agencies have 

 been present in their natural African reservoirs since time 

 immemorial, and that they were largely responsible for 

 impeding the progress of civilisation on the continent as a 

 whole. It is my purpose on this occasion to call attention in 

 broad outline to certain factors in the development of South 

 African resources, in the hope of stimulating discussion on the 

 advancement of scientific research in connection hereM'ith, for 

 it is apparent that Africa is destined not to yield except to 

 the pressure resulting from the application of the combined 

 experience gained by scientific workers throughout the world. 

 In coping with Africa, one maj" well ask whether the strongest 

 is strong enough. 



Entomological Research ix its Relation to 

 Human Welfare. 



Human Diseases. 



It is only necessary to mention the alliance between 

 sleeping sickness and the tsetse fly ; malaria and yellow fever 

 and the mosc^uitoes ; typhus fever and the louse; typhoid, 

 dysentery and other diseases and the house fly, to impress even 

 the most sluggish intellect with the fact that there is great 

 need for thorough research into the question of human 

 diseases and the agencies tliat disseminate them. 



Independent of any question of the transmission of disease, 

 there are two insect.s — the louse (Pediculus humanus) and the 

 bedbug (Cinie.r lerfulaiia) — that deserve special attention on 

 account of their influence on the efficiency of labour. 



No liuman being can rest properly under an infestation of 

 either lice or bedbugs, or both, and it seems reasonable to 

 suppose that the disturbance will be reflected in working 

 capacity and be in direct proportion to the degree of infesta- 

 tion. I have frequently received requests for help in com- 

 bating either one or both of these pests, and the degree of 

 infestation found on careful inspection surpasses imagination. 

 It is no uncommon thing to find Kaffirs sleeping on the ground 

 in the open air rather than brave the swarms of bedbugs in 

 the huts or barrncks. Cattle and sheep are dipped for ticks 

 and scab '' because it pays." I submit that it will also pay 

 in the increased efficiency of labour to fumigate the clothing 

 and the sleeping quarters of the lower classes witli prus^ic 



