RIVER, EAST AFRICA PROTECTORATE. 275 



oedema in the feet and ankles, but I eould find no trace of enlarged cervical 

 glands and he showed no signs of emaciation. He was a man past middle age 

 and had a little grey in his hair, but I believe he was suffering from nothing 

 more than advancing old age. On enquiring as to whether these Masai knew or 

 suspeeted the tsetse-fly of producing disease or death in human beings, I could 

 find no evidence of any idea of the kind. They knew and admitted that they 

 occasionally lost cattle as a result of their being bitten by tsetse-fly, but they said 

 this very seldom happened and that they had no cattle sick at the time. I saw 

 the cattle and could find none showing signs of disease. Among the slice]) and 

 goats I found two, one sheep and one goat, which were diseased and much 

 emaciated and were said to have been ill for three months. I examined the 

 blood of both these animals, but could find no trypan osomes. 



Physical Features of the Fly-area. 



The Amala river from the Government post at 5,500 ft. Hows with considerable 

 current as far as the point on the map marked " rapids." There is no dense bush 

 or forest on this part of the river, only a very narrow fringe of trees and 

 bush actually on the edge of its banks. At the point where the rapids are, the 

 escarpment of 6,000 ft. altitude, which runs all along the west bank of the river 

 into German territory, approaches the river within 200 yards. Above this point 

 tsetse-fiy do not occur. Immediately below it the escarpment bends away from 

 the river, as can be seen from the map, and the west bank opens out into a broad 

 plain of park-like country, fine grazing land, studded with occasional yellow- 

 barked acacia trees. At the lowest point I reached, just below the Enderrit 

 river, there was a distance of at least seven miles from the Amala river across 

 the plain to the escarpment, with a fall of about 200 ft. from the foot of the 

 escarpment to the river, and below this point the distance is much greater. 



This plain is intersected by numerous small water-courses coming down from 

 the escarpment, some of which contain a little running water all the year round 

 from springs, while others dry up, except for a few pools, towards the end of the 

 dry season. The banks of all these water-courses are over-grown with dense bush 

 and forest, at the sources extending for perhaps only 30 to 50 yards on each 

 bank, but gradually widening out as the streams approach the Amala to as much 

 as 250 or 300 yards. This bush is very similar to bush in which I have seen 

 G. palpalis in Uganda and the Congo, and is in every way suitable for tsetse-fly. 

 It consists of some large forest trees, with smaller ones in between and with 

 quantities of creepers, affording excellent shade, which in some places is very 

 dark, in others mottled with sun-light. This forest is not full of dense under- 

 growth, but is comparatively open, so that it is possible to walk about and even 

 lead a mule without much difficulty. There is no grass growing beneath the 

 trees, though in some places there is a thin growth of low herbaceous plants, but 

 more usually the ground is covered with dry leaves and composed of leaf-mould. 

 The temperature in this bush, taken only upon one occasion, registered 80° F. 

 maximum and 58° F. minimum, at an altitude of 5,100 feet. The soil under- 

 neath these belts of bush apparently never becomes very dry and in some places 

 is quite sodden, so that there is ample moisture combined with the shade. 



