CASCADES. 285 



the generality of permanent winds. The trees and 

 shrubs bend from these, and are dwarfed and stunted 

 by them ; but they extend their twigs, and are fresher 

 in their leaves on the side next the waterfall. In such 

 places their duration is also increased; and a tree, 

 which has the advantage of this constant watering 

 upon the leaves, is much less dependent upon the 

 roots, and therefore will continue to show vigorous 

 leaves after the trunk is much more hollowed and con- 

 sumed by age. We have mentioned that those places 

 that are most favourable to vegetation, are also most 

 favourable to animal life, though they may not be 

 most healthy for man, and those animals that resemble 

 man the most in their structure and economy. This 

 holds true with regard to the vicinity of cascades, 

 which, except too a few peculiar species, are the places 

 in which to seek the animals as well as the plants of an 

 alpine region. There are no places in this country 

 where waterfalls do not chronicle the lapse of a very 

 considerable number of years ; and sometimes the 

 ravine that they have worn extends miles in length ; 

 nay, there are many instances where the action of 

 the stream can be traced for several miles, quite 

 through a ridge, so that the cascade which had 

 been gradually increasing in height for the one 

 half of its course, and diminishing for the other, 

 has now worked down to the lowest part of the lake 

 from which it had its origin. One remarkable instance 

 of this, is to be found on the river Tay, in Perthshire, 

 at the celebrated pass of Killicrankie, where the whole 

 upper valley of Athol has obviously, at one time, been 



