AND THE VICTORIA NYANZA 



53 



or five miles round the nioinitaiii mass at tins altitude (an average (5, 000 

 feet), it not infrecjuently ha})pens that the mouth of a cave exactly coincides 

 with the descent of a waterfall from the edge of the precipices far above, 

 the water thus serving as a curtain to screen the mouth of the cave from 

 sight when viewed in front. The native path leading to the cave will thus 

 take you dry-shod under a river, and when you are seated at the mouth of 

 a cave you may see the splendid glowing landscape of the plains through 

 an opal-tinted veil of water. What is the origin of these caves ? One 

 can state no precise opinion with our present limited information. It is 



r 



44. "TKK.MENDOIS BLTTKESSE.S AMj PKErlFlTors rl.lKE.S 



true that these recesses at the base of the preciiiitous terraces so often 

 coincide with the overhanging cascade of a river that quite possibly there 

 may have been at one time a percolation of tlie stream from above, through 

 the crumbling rock, whicli hollowed out these caverns. Later on, some 

 cement-like material bronj^ht down bv the water from above, or some hwa 

 flow, may have completely closed these cracks through which the percolation 

 took place, with the result that the stream once burrowing through the 

 cave now flows in a shallow rock channel high above it, and dashes itself 

 in sheer falls of 100 feet or more, arching over the mouth of the cave, 

 and continuing its course along a less precipitous gorge below. Certainly 



