THE FOEESTS 



145 



and crevices, but the Sierra as a whole would have 

 been a bare, rocky desert. 



It appears, therefore, that the Sierra forests in 

 general indicate the extent and positions of the an 



cient moraines as well as they do lines of climate. 

 For forests, properly speaking, cannot exist without 

 soil; and, since the moraines have been deposited 

 upon the solid rock, and only upon elected places, 



10 



