168 • DR. SCHWETZ. 



uncontrollable fire produces among these flies a general rush for safety, and a 

 temporary disturbance of their habits. For the same reason a terrified antelope 

 will sometimes arrive in the midst of a large station in broad daylight. But the 

 danger passed, everything returns to its usual order, and some weeks after, in order 

 to find morsitans in the vicinity of Katompe, it had to be sought for in its habitual 

 residence, some kilometres east of the station. 



Summary. 



The hypothesis Avhich I have previously suggested, that the limit of morsitans 

 coincides more or less with that of the park (at least in Katanga), has just been 

 confirmed by several new observations. But sometimes the range of the fly 

 terminates before the disappearance of the park. This double disappearance is 

 generally gradual. 



Between 9° and 5° S. Lat. the western limits of the park and of G. morsitans 

 coincide roughly with the Lualaba-Lomami watershed, but most frequently they 

 disappear a little to the east of this line, that is to say, they do not quite reach the 

 Lomami basin. 



In this region, between the Lualaba and the Lomami, the park and morsitans 

 gradually disappear in the neighbourhood of 5'30° S. Lat., that is, a little south of. 

 Kongolo. 



