VALLEYS ON RUWENZORI. 103 



mould and lias been named Disperis nemorosa by 

 Mr. Eendle. 



In such a place vegetation of a low type can 

 multiply indefinitely, because there is no check 

 either by drought or cold. There is a want of 

 sunlight and of the higher insects or sunbirds, so 

 that there are very few brilliant flowers except on 

 the very tops of the trees and high-climbers. Such 

 flowers as do exist are usually pale coloured and 

 occasionally large, and thereby gain an advantage 

 in being more conspicuous ; though the cause is 

 simply the dim diffused light and the want of 

 check to increase in the size of the petals. Leaves 

 usually become large, flaccid, and drooping in such 

 places, and this is an effect of the same thing, 

 which once more exemplifies the wa}^ in which 

 environment directly produces such variations as 

 are distinctly advantageous under the circum- 

 stances. 



After trying all the paths around the Wimi 

 (which were very bad, as the ascents were usually 

 precipitous and almost always slippery with wet 

 mud and choked by branches), I determined to 

 proceed down to Katwe, the Salt lake, and try 

 the western side of the chain. I therefore started 

 down the valley to Butanuka, passing on the way 

 a hot spring, which joins the left bank of the Wimi 

 just before it emerges from the hills. 



