THE WILD FAUNA OF THE EMPIBE 23 



A friend of the writer has lately been informed by Professor Koch 

 that he believes Glossina palpalis to be the only transmitter. As 

 one of the arguments in support of this view the Professor made 

 the following statements. In the portion of German East Africa 

 on the western shore of Lake Victoria, and to the south of 

 Uganda, Glossina morsitans is abundant, but there are no G. pal- 

 palis. In spite of the fact that natives from the infected areas 

 further to the north have been coming into this district for some 

 years past, the disease has never spread, as it might be expected 

 to have done were it transmissible by Glossina morsitans. It is 

 devoutly to be hoped that Professor Koch's belief will prove well 

 founded. In the meantime, however, the question cannot be re- 

 garded as settled, and it is much to be wished that the Govern- 

 ments of the various Colonies and Protectorates concerned will, 

 without delay, make the necessary arrangements for deciding this 

 all-important matter once for all, by means of an exhaustive series 

 of properly controlled experiments. 



The Role of Glossina palpalis in Connection with Sleeping 



Sickness. 



Lest it should be imagined by the lay reader anxious for the 

 preservation of the wild fauna of Africa that everything in con- 

 nection with the part played by Glossina palpalis in the trans- 

 mission of sleeping sickness is now understood, it is perhaps as 

 well to explain that at the present time this is far from being the 

 case. Although this tsetse-fly is as yet the only living agent that 

 has been proved by experiment to convey the parasite that is the 

 cause of the disease, and although (as has been shown by the 

 members of the Sleeping Sickness Commission of the Royal 

 Society, in Uganda, and by those of the expedition of the Liver- 

 pool School of Tropical Medicine to the Congo, 1903-5, in the 

 Congo Free State) the occurrence of sleeping sickness and G. pal- 

 palis correspond in such a way that the disease is never found 

 epidemic or endemic in any locality in which this species of tsetse 

 is not present, in reading accounts of transmission experiments it 

 is impossible not to be struck with the fact that very large numbers 

 of flies are usually requisite in order to produce a successful result. 

 Thus it has recently been stated by the late Dr. J. E. Dutton and 

 by Drs. J. L. Todd and J. W. B. Hannington, of the Liverpool 

 School of Tropical Medicine, that : * The experiments of all ob- 

 servers show that it is frequently necessary to feed hundreds, 

 almost thousands, of flies on a susceptible animal before it becomes 

 infected. ' ^ The result of all experiments hitherto performed tends 

 to the conclusion that Glossina palpalis is a mechanical carrier of 



^ Annals of Tropical Medicine and Parasitology, vol. i. No. 2 (June 15, 

 1907), p. 212. 



