ix SUDDEN INCREASE OF TSE-TSE FLIES 159 



Leshuma and Kazungula either in 1885 or in 1888, 

 there were still a few lingering there in the latter 

 year. There were so few in the early part of 1888, 

 however, that probably none were to be seen during 

 June and July, when the nights were very cold, but 

 later on in this same year they increased very 

 rapidly in numbers, as I think, owing to the fact 

 that my own and Mr. Reid's cattle deposited a 

 great deal of dung all along the waggon track 

 leading down to Kazungula. It was in June of that 

 year (1888), after I myself had crossed the Zambesi 

 on an expedition to the north, that Jan Weyers, an 

 old Dutch hunter, took my waggon by night through 

 the old " fly " belt between Leshuma and Kazungula 

 in order to trade with the natives living on the 

 Zambesi, sending the oxen back to Leshuma the 

 following night. In the same month, or a little 

 later, Mr. Percy Reid and his party brought their 

 waggons to Leshuma, and their oxen pulled them 

 backwards and forwards several times between that 

 place and Kazungula. There was thus a great deal 

 of cattle dung, which is, of course, precisely the same 

 as buffalo dung, all along this short stretch of 

 waggon road. For some reason this driving of 

 cattle backwards and forwards between Leshuma 

 and the Chobi caused an extraordinary increase in 

 the number of tse-tse flies. All the natives who 

 travelled the road remarked upon it, and both they 

 and Jan Weyers assured me that they had thought 

 the " fly " was almost absolutely extinct in this 

 district, as in the previous year, even in the hot 

 weather before the rains, very few had been seen. 



However, when I went down to the river in 

 August (1888) on my way to the Barotse country, I 

 found a good many tse-tse flies along the track, and 

 by November they had become very numerous. 

 As Mr. Reid and his party did not return to Panda- 

 matenka by way of Leshuma, but went along the 



