Through the SemHki Valley 209 



they run as follows: Gessi 4,769, Emin 4,815, Speke 4,901, 

 Stanley 5,125, Baker 4,875, Ludwig of Savoy 4,663 metres. 

 The Ruwenzori glaciers are included among the so-called 

 equatorial type ; that is to say, they form a kind of ice- 

 cap, at times of great dimensions, and more or less entirely 

 cover the summits of the mountains. From the caps, branches 

 stretch out down below, which enter the valleys and only rarely 

 extend beyond the lower boundary of the perpetual snow, which 

 lies between 4,450 and 4,500 metres. In consequence of the 

 position of the glaciers, the moraines at the sides are quite in- 

 considerable, and even the ground moraines do not appear to 

 possess any noteworthy development, at least, judging by the 

 terminal moraines, which never exhibited any important feature. 



Another circumstance worthy of notice is that the water which 

 spurts out from the fore part of the glacier never has that dull 

 appearance which the melted snow of the Alpine glaciers exhibits 

 under similar conditions. The water is perfectly clear, which 

 proves that the progress of the glaciers, at the present time, at 

 least, is quite inconsiderable. The erosion also must be very 

 slight, which will account for the absence of ground moraines. 



The tremendous development which the glaciers of the Ruwen- 

 zori group underwent during the glacial period is a geological 

 phenomenon of great importance. We learned from the investi- 

 gations of Dr. Roccati, the geologist to the Duke d'Abruzzi's 

 expedition, that they have extended down to 1,500 metres on 

 the eastern side in the Mobuku valley, whilst now they are no 

 lower than 4,200 metres! 



I would particularly desire to emphasise these statements. If 

 we really may accept such a glacial period for Equatorial Africa, 

 which observations on the Kenia would tend to prove, many 

 questions of a botanical and animal geographical nature would 

 easily be solved. The almost bewildering conformity which is 

 exhibited in the vegetation of mountains which are now divided 

 by broad steppes or forest regions of purely tropical character, 

 and in such types that their dissemination through birds or the 

 air is not to be thought of, would then be explained. 



2 B 



