183 



inuy be tluit tsetse will be found on one side of :i ruii<>e of bills, 

 wbilst on tbe otber side none bas been known witbin tbe nvenioiy 

 of tbe oldest inbabitaut. 



After tbe outbreak of rinderpest in 18U(), tbe Hy-belts in 

 Soutbern E-bodesia underweut an extraortlinary sbrinka^c, 

 A\bilst in many districts fly disappeared altogetber. It must 

 be confessed tbat since tben fly has sbown a tendency in some 

 ])laces to spread back to its old boundaries, but not hcijoiid, 

 wbilst in otbers, fly bas not reappeared at all, and tliis is specially 

 noticeable on tbe Pungwe Flats, and the stretcb of country 

 between tbe Portuguese border and tbe coast on tbe east. 



Tbe scattered nature and limited extent of tbese fly-infested 

 areas materially reduces tbe danger of any serious spread of 

 sleeping sickness in Soutbern Rbodesia and moreover renders its 

 occurrence of secondary importance, for these areas are, in 

 almost all instances, remote from European settlement, and are 

 only sparsely populated by natives. The removal of persons 

 from any fly-infested area would therefore not be a difficult 

 matter at any time should the necessity arise. 



Tbe author, in conjunction with Dr. F. 0. Stohr, Mr. Carbutt 

 and Mr. Jack, carried out an investigation of tbe fly area in tlie 

 Sebungwe district, in order to ascertain if any cases of trypano- 

 somiasis existed amongst the natives. They examined every 

 individual who could be found, including men, women and 

 children, and as a result 12 cases were recorded. Tsetse-fly was 

 encountered or reported to exist by natives over an area rouglily 

 TO miles east and west, and 40 miles north and soutli, and 

 stretching from the Nagapandi River on tbe west to a point 

 some 20 miles to the east of the Sengwe River on tbe east, and 

 from the Sijalila Hills on the north to tbe Mzola River on tbe 

 south, roughly an area of 4,000 square miles. At Ivariyangwe, 

 which was the Government station of the district, fly was reported 

 as having been seen on several occasions, but the investigators 

 saAv none during their visit. Fly was first met watb at Simasu's 

 on the Lubu River, some 5 miles to the east of Kariyangwe, and 

 from there onward along the route followed it was fairly 

 plentiful. 



The relationship of fly to game in this area is somewhat diili- 

 cult to follow, and its distribution would appear to be more 

 influenced by geographical features than by tbe movement of 

 game. 



Tbe natives within tbe fly-belt have no cattle, few dogs and 

 only small herds of sheep and goats, and in most cases a certain 

 percentage was found to be infected with trypanosomiasis, and 

 rabbits were successfully inoculated from human beings, dogs 

 and goats. Though infected sheep, dogs and goats were almost 

 generally distributed throughout villages in the fly-belt tbe 

 author says that it is interesting and probably important to 

 note that almost all human beings found to be infected were 

 either resident within, or previous to the period of infection 

 bad visited, a certain small area of country wliicli is situated on 

 the liusi River, a tributary of tbe Sengwe, tbe natives in 

 tbese villages having little communication with those of villages 



