330 J, LeConte—Ancient Glaciers of the Sierras. 
Below this and before reaching Yosemite proper, there is a suc- 
cession of small meadows, three in number, separated by debris 
piles. These have been formed, I think, in the same manner 
as Mirror lake, viz., by water accumulated behind moraines left 
by the retreating glacier. 
IL TuotuMNE GLACIER. 
lower or western side, thus: Vij In a 
HL = 
word they are perfect examples of moutonnée forms on a grand 
scale. But what interested me far more than anything else, 
was that the main branch of the Tuolumne glacier, far UP 
among the cliffs and peaks of Mt. Lyell, séil/ exists as a living 
glacier, in a feeble state of vitality it is true, but certain] liv: 
ing. My attention was first directed to this fact by Mr. Mum, 
and I visited Mt. Lyell with him for the purpose of convineig 
myself of so interesting a fact. 
he summits of Mt. Lyell (13,300 feet high) and Mt. McClure 
consist of a vast amphitheater, irregularly circular in form and 
several miles in diameter, surrounded by almost perpendicular 
cliffs with sharp jagged crests. In this cireular amphitheater 
| there still exist extensive snow-fields, no doubt of considerable 
__. thickness. In glacial times this great amphitheater was com- 
_ pletely filled to the brim with snow. It was the womb in 
_ * See this Journal, for January, vol. v, p. 69. 
