SLEEPING SiCKNKyS COMMISSION IN UGANDA. 223 



been caused by tsetse-flies. During February and March, and again later 

 in the year, during August and September, as many as 100 fly-boys were 

 •engaged scouring this district for biting flies. Tahamis, Ucematopota and 

 Chrysops were brought in, but not a single tsetse, although a reward ot 

 *5 rupees was offered for eacli specimen. The commonest Tahanus in this 

 district during August was variatus. Walk, [a colour variation of 2. tceaiola, 

 P. de B.]. 



'' It may therefore, in our opinion, be concluded that the trypanosome 

 disease caused by Trifpanosoma pecorinn can be carried from sick to healthy 

 animals without the help of Glossina, but what other s])ecies of fly, if any, 

 acts as carrier is merely a matter of speculation at present/^ 



Experiments were made to test the belief, expressed by Montgomery and 

 Kinghorn, that flies of the genus Stomoxys are capable of transmitting this 

 disease ; but although these experiments w^ere persevered in for several 

 months, they remained neoative. The authors contend that ^' Stomoxys are 

 so numerous in every part of the country, all the year round, that it seems 

 inconceivable that they can act as carriers. From October, 1908, until the 

 following September, although numerous cases of cattle with TrypanosQina 

 pecorum in their blood grazed all day long with healthy cattle, yet not a 

 single case of infection took place. The Stomoxys were exceedingly numerous 

 all this time, forming a small cloud of flics round the cattle, and passing 

 constantly from one animal to another, being driven hither and thither by the 

 i-apidly swishing tails. This is a natural experiment on a large scale. It 

 will therefore require very convincing proof to bring tliis Commission to the 

 belief that Stomoxys are carriers of this disease.''^ 



Cattle as a possible Reseri'oir of the Virus of Sleeping Sickness. 



It has hitherto been generally considered that man himself constituted 

 the main reservoir of Trypanosoma (jamhiense, but seeing that the Glossina 

 jralpalis on the shore of Victoria Nyanza have remained infective for some 

 two years after all the natives had been deported, it was necessary to 

 reconsider that opinion. 



As cattle have been numercms in the past along the Lake shore it was 

 surmised that they might prove to be a possible reservoir of the disease ; and 

 if so, the same would probably be true of wild antelopes, whose presence 

 might thus account for the continued infectivity of the flies on the Lake 

 shore. 



As a result of various experiments, tlie following general conclusions were 

 reached : — 



'' It has been proved by experiment that cattle may act as a reservoir of the 

 virus of Sleepinii Sickness, and that healtliy animals may be infected from 

 them by means of Glossina palpalis. 



