194 THE MOUNTAINS OF CALIFORNIA 



and even clinging like mountain pines to rifts in 

 granite precipices; and since it has also been shown 

 that the extra moisture found in connection with 

 the denser growths is an effect of their presence, 

 instead of a cause of their presence, then the notions 

 as to the former extension of the species and its 

 near approach to extinction, based upon its sup 

 posed dependence on greater moisture, are seen to 

 be erroneous. 



The decrease in the rain- and snowfall since the 

 close of the glacial period in the Sierra is much less 

 than is commonly guessed. The highest post-gla 

 cial watermarks are well preserved in all the upper 

 river channels, and they are not greatly higher than 

 the spring floodmarks of the present ; showing con 

 clusively that no extraordinary decrease has taken 

 place in the volume of the upper tributaries of post 

 glacial Sierra streams since they came into exis 

 tence. But in the mean time, eliminating all this 

 complicated question of climatic change, the plain 

 fact remains that the present rain- and snowfall is 

 abundantly sufficient for the luxuriant growth of Se 

 quoia forests. Indeed, all my observations tend to 

 show that in a prolonged drought the Sugar Pines 

 and firs would perish before the Sequoia, not alone 

 because of the greater longevity of individual trees, 

 but because the species can endure more drought, 

 and make the most of whatever moisture falls. 



Again, if the restriction and irregular distribution 

 of the species be interpreted as a result of the des 

 iccation of the range, then instead of increasing as 

 it does in individuals toward the south where the 

 rainfall is less, it should diminish. 



