220 A NATURALIST IN MID-AFRICA. 



Usambara,* and the Stevenson Eoad colonies are 

 very closely allied. They are chiefly steppe or 

 grassy countries, though often covered by scattered 

 trees ; they all lie on an average at an altitude of 

 between 3,500 and 6,600 feet ; the climate is not 

 as dry as the Victoria region, but it is a warm 

 one, and the rainfall also occurs between October 

 and April. Those parts of xAbyssinia, Ruwenzori, 

 Kenia, and Kilimandjaro (to which one may add 

 Mfumbiro and Elgon) which lie between those 

 altitudes (3,500 and 7,000 feet) possess many of 

 the forms which are found in the Central Water- 

 shed, and perhaps also in districts 4, 9 and 11 ; 

 but the inhabitants of the very wet and cold Cloud 

 regions of Ruwenzori, Kenia, Kilimandjaro, and the 

 Kiriba above 7,000 feet are for the most part 

 utterly different to anything found on the lower 

 levels, and are obviously a separate migration 

 which has followed the same course as that of 

 the Central Watershed plants at a time when 

 there was probably a continuous ridge above 

 6,600 feet from Abyssinia to Mount Mlanje and 

 Mashonaland. This explains why some of them 

 also extended to the Cameroons and Fernando Po, 

 where, so far as I know, the plants found below 

 7,000 feet have not penetrated. Thus the district 

 may be summarised as follows : — 



I use tins name to designate all parts of German East 

 Africa, except the Central Waterhed, which are over 3,000 

 feet in altitude. 



