THE FORESTS 195 



If, then, the peculiar distribution of Sequoia has 

 not been governed by superior conditions of soil 

 as to fertility or moisture, by what has it been 

 governed ? 



In the course of my studies I observed that the 

 northern groves, the only ones I was at first ac 

 quainted with, were located on just those portions 

 of the general forest soil-belt that were first laid 

 bare toward the close of the glacial period when 

 the ice-sheet began to break up into individual 

 glaciers. And while searching the wide basin of 

 the San Joaquin, and trying to account for the 

 absence of Sequoia where every condition seemed 

 favorable for its growth, it occurred to me that this 

 remarkable gap in the Sequoia .belt is located ex 

 actly in the basin of the vast ancient mer de glace 

 of the San Joaquin and King's River basins, which 

 poured its frozen floods to the plain, fed by the 

 snows that fell on more than fifty miles of the 

 summit. I then perceived that the next great gap 

 in the belt to the northward, forty miles wide, ex 

 tending between the Calaveras and Tuolumne 

 groves, occurs in the basin of the great ancient mer 

 de (/lace of the Tuolumne and Stanislaus basins, 

 and that the smaller gap between the Merced and 

 Mariposa groves occurs in the basin of the smaller 

 glacier of the Merced. The wider the ancient glacier, 

 the wider the corresponding gap in the Sequoia belt. 



Finally, pursuing my investigations across the 

 basins of the Kaweah and Tule, I discovered that 

 the Sequoia belt attained its greatest development 

 just where, owing to the topographical peculiari 

 ties of the region, the ground had been most per- 



