THE SEQUOIA 325 



the species and its near approach to extinction, 

 based on its supposed dependence on greater 

 moisture, are seen to be erroneous. Indeed, all 

 my observations go to show that in case of pro- 

 longed drought the sugar pines and firs would 

 die before Sequoia. Again, if the restricted and 

 irregular distribution of the species be interpreted 

 as the residt of the desiccation of the range, 

 then, instead of increasing in individuals toward 

 the south, where the rainfall is less, it should 

 diminish. 



If, then, its peculiar distribution has not been 

 governed by superior conditions of soil and 

 moisture, by what has it been governed? Sev- 

 eral years before I made this trip, I noticed that 

 the northern groves were located on those parts 

 of the Sierra soil-belt that were first laid bare 

 and opened to preemption when the ice-sheet 

 began to break up into individual glaciers. And 

 when I was examining the basin of the San 

 Joaquin and trying to account for the absence of 

 Sequoia, when every condition seemed favorable 

 for its growth, it occurred to me that this remark- 

 able gap in the belt is located in the channel of 

 the great ancient glacier of the San Joaquin and 

 Kings River basins, which poured its frozen 

 floods to the plain, fed by the snows that fell on 

 more than fifty miles of the Summit peaks of the 

 range. Constantly brooding on the question, I 

 next perceived that the great gap in the belt to 



