GRAPHIC DESCRIPTION OF AFRICA. 235 



districts the rivers have to find their way across open lowlands 

 where the volume of water soon diminishes, and is lost in the 

 parched earth, the country here is like a well-filled sponge. The 

 result of this abundant moisture is that the valleys and fissures of 

 the earth through which the water flows, whether in the form of 

 little brooks and streamlets, or of great rivers, are clothed with all 

 the majesty of a tropical forest ; while an open park-like glade, the 

 chief feature of which appears at the first glance to be the amazing 

 size of its foliage, fills up the higher-lying spaces between the water- 

 courses and the galleries. 



The number of distinct types of trees, and the variety of forms 

 among the undergrowth, is very great. Trees with large trunks, 

 whose height throws into the shade all the previously seen specimens 

 of the Nile flora, not excluding the palms of Egypt, are here found 

 in serried ranks, without a break, and beneath their shelter the less 

 imposing platforms are arranged in terraces. 



LEAFY CORRIDORS WITHIN VIRGIN FORESTS. 



In the interior of these virgin forests, leafy corridors, rivalling 

 the temple walls of Egypt, lie veiled in deep perpetual shadow, and 

 are spanned by a triple roof of foliage, rising vault above vault. 

 Seen from without, the galleries appear like an impenetrable wall 

 of the densest leafage, while from within corridors of foliage open 

 out in every direction beneath the columns of the tree stems, and 

 are filled with the murmuring voice of springs and water-courses. 



The avei'age height of the roof of leaves measures from 

 seventy-five to ninety feet ; but very often these galleries, seen from 

 without, by no means produce the imposing eflfect which is felt from 

 within in looking up from the depth of the valley or the water-side ; 

 because in many places the depression of land or water which makes 

 up the gallery or tunnel-like character of the scene scarcely allows 

 half of the forest to rise above the level ground, many galleries 

 being entirely sunk in the depression. Great tree trunks, thickly 

 overgrown with wild pepper, rise from the depths, and support wide- 

 spreading branches draped with lichens and mosses, above which 

 towers the remarkably fine tree called the elephant's ear, which 



