THE CONGO BASIN 231 



woods and grass-lands. Such characteristic denizens of 

 the savana as the ceiba, dragon-tree, borassus palm, &c., 

 by their recurrence among the inter-river landscapes, 

 suggest a similarity of conditions between the two 

 physical environments. In the lower districts of the 

 Congo, the selva is limited to the shores and the islands : 

 savanas become the chief plant formation, corresponding 

 with a lower atmospheric humidity. 



Human settlements are scattered along the rivers, 

 where, by fishing, hunting, and a minimum of agriculture, 

 as well as by the collection of rubber, scanty populations, 

 once more prosperous and numerous, eke out the 

 meagre living that satisfies them. 



Angola. The northern edge of the high austral 

 African plateau curves round the Congo basin. Its 

 north-western extremity passes quite close to the lower 

 Congo, forming the region known as Angola, which 

 possesses a low and narrow coastal shelf. This coastal 

 strip is but the northern spur of the south-western desert, 

 and its rainfall does not exceed eight inches yearly. 

 Consequently its vegetation repeats that of Somaliland 

 or Gazaland : meagre and patchy swards of stiff grass, 

 with a sprinkling of thorn-bush and stunted trees, where 

 the forms of the candelabra euphorbia and the baobab, 

 the aloe and the sanseviera are conspicuous. 



On the foot-hills at the back, the thorn-bush thins 

 out and soon mingles with jungles of large-leaf ever- 

 greens. Climbing up the edge of the plateau, at about 

 1,000 feet, one crosses the southern outlier of the West 

 African coast forest, comprising high trees and lianas, 

 which has been already mentioned. The forest belt 

 rapidly decreases in size and profusion, as one approaches 

 the brink of the tableland, and after passing through 

 a fringe of hill -bush one steps into the boundless savanas 



