ACADEMY OF SCIENCES. 259 



on Aquila Besmursi, by J, H. Gurnej ; London, 1802. Report 

 on Observations of Encke's Comet, during its return in 1871, by 

 A. Hall and W. Harkness ; Washington, 1872. Memoirs of the 

 New Russian Society of Agriculture, Vol. I, Parts 1, 2 and 3 : 

 Odessa, 1872 ; Proc. Am. Acad. Arts and Sciences, Vol. VIII, 

 pp. 305-408, 1872. 



Donations to the Museum : Specimens of Orchilla, from Lower 

 California, by Henry Chapman. Specimens of a medicinal plant, 

 from near Shasta, by Mr. Hastings, said to be a cure for rheum- 

 atism. 



Prof. Joseph Le Conte gave the result of observations made by 

 him, upon the occurrence of glaciers and glacial action in the 

 Sierras, of which the following is an abstract : 



On Some of the Ancient Glaciers of the Sierras. 



BY JOSEPH LE CONTE, PROFESSOR OF GEOLOGY, UNIVERSITY OF CALIFORNIA. 



The author states, that in his travels amongst the high Sierras, during the 

 past summer, he observed the evidences of many ancient glaciers. Of these, he 

 gives a more particular description of the most remarkable, in the order in 

 which he observed them. 



1. The Merced, or Yosemite Glacier. — He believes that a glacier once 

 filled Yosemite to its brim. The evidence of this he finds in the ancient mo- 

 raines and intervening meadows, and in the glaciated forms on the north wall. 

 This great glacier received tributaries, which may be very clearly traced, by 

 means of erratics and glaciated surfaces, to Mount Hoffman, to Cathedral Peak?, 

 to Mount Lyell group, and to Mount Clarke group. He states further, that a 

 general view of the surface configuration of the country about Yosemite, reveals 

 a remarkable resemblance to montonnee rocks on a huge scale, and strongly 

 suggests that in early glacial times, not only the canons, but the whole sur- 

 face, including every dome and peak, was covered by and moulded beneath an 

 universal ice-sheet. 



After a somewhat detailed account of the beautiful glacial signs about Cathe- 

 dral Peaks, the author passes to 



2. The Tuolumne Glacier. — This great glacier, as already explained by 

 Whitney, was formed by tributaries from McLane's Pass, Mount Dana, Mono 

 Pass, and especially from Mount Lyell group, which, meeting at Soda Springs, 

 filled the Tuolumne meadows, smoothed and rounded in the most perfect man- 

 ner the granite hills which lay in its path, overflowed its banks, and sent 

 an icy stream down the Tenaya Canon to the Yosemite Glacier, while its 

 main flood went down the Tuolumne Canon into and beyond Hetch-hetchy. 

 It must have been at least forty miles in length. 





V 



