1904.] on Sleeping Sickness in Uganda. 517 



package came in it was examined for tsetse flies. If the parcel 

 contained one or more tsetse flies, a red disc was stuck on a large 

 map over the locality from which the flies had been sent. If, on the 

 other hand, no tsetse flies were found, a blue disc was fixed over 

 the spot. 



In the same way and at the same time a second map was pre- 

 pared, to show the clistribution of sleeping sickness. That is to say, 

 if the note accompanying the collection of flies stated that sleeping 

 sickness was prevalent, then a red disc was placed over the locality, 

 and if, on the contrary, no cases of sleeping sickness were reported, 

 a blue disc was af&xed. 



It is evident that two maps so prepared should show at a glance 

 whether the distribution of sleeping sickness and this tsetse fly corre- 

 spond or not. 



The accompanying maps are prepared from these two maps. On 

 comparing them the similarity of the distribution of sleeping sickness 

 and Glossina palpalis is self-evident. 



In order to work out more minutely the habits of the Glossina 

 paljmlis, the peninsula on which Entebbe stands was taken in detail 

 and carefully searched for the fly. 



The result of this showed that the fly is only found on the shore 

 of the lake where there is forest. This forest is thick jungle with high 

 trees and dense undergrowth. The fly is never found on open sandy 

 beaches backed by grass plains, even although there may be some 

 email scrub near the water's edge. It is never found in the grass of 

 the grassy plains, even though the grass be long and tangled. It has 

 not been found by us in banana plantations, and not at any time far 

 from the lake shore. 



The habitat, then, of this fly is the shore of the lake where there 

 is forest. In Busoga, on the other hand, it appears to be found 

 further inland, but what the physical characters of this province are 

 which would account for this I have not learned. The fly also passes 

 dovvn the Nile as far as Kakoge Ferry, some fifty miles north of the 

 Ripon Falls, and it has even been received from Fajao on the Somer- 

 set Nile, and from Tengri and the Achwa River, still further north, 

 and near Wadelai, and also from Lake Albert. 



It is important that the distribution of this fly should be fully 

 worked up, but enough has been done to show that the distribution 

 of this species of tsetse fly is, like sleeping sickness, confined to the 

 shores of the lake and the islands. It is on the densely-wooded 

 shore of the lake that the half-naked natives of the mainland and 

 islands meet in thousands to trade in fish, bananas, earthenware, 

 etc. If the Glossina palpalis can act as a carrier of the trypanosome 

 of sleeping sickness, the circumstances could not be made more 

 favourable than they are for the spread of the disease. 



The next point, therefore, to solve is : " Can this tsetse fly carry 

 this trypanosome from persons suftering from sleeping sickness to 

 healthy animals ? " 



