GLACIATION IN THE YOSEMITE VALLEY 219 

 To Asa Gray 



August 22, 1878. 



Here I am with my wife immured in a little inn to which 

 we came yesterday, to view the beauties of Killarney, which 

 have ever since been obscured by torrents of rain accompanied 

 by a furious gale, which for aught I know has blown here 

 ever since I sighted the S. of Ireland last October. It is a 

 beastly climate. How different from Nevada ! 



How stupid of me to forget the Miocene Flora of Ice- 

 land ! which I knew of. It is well my letters to you are 

 not publications ! 



Our difference as to ' gouging out ' of Yosemite is pro- 

 bably verbal only. I never intended it to be understood 

 ' that the Glaciers had initiated the valley,' but I think 

 that the mass of material has been removed by glaciers, 

 and that they have given its sides their configurations to a 

 much greater extent than you do. A glacier enduring for 

 ages in such a valley must have carried away an incredible 

 amount of stuff, and not merely ' scraped the sides.' That 

 sort of granite offers no resistance to ice, such as Limestone, 

 Porphyry, Slate, and other Metamorphic rocks do. 



Just regard the amount of solid rock on the lateral and 

 medial moraines of any glacier at any one time add the 

 grooved detrition of sides and bottom and sum up the 

 annual loss of material it is stupendous. You say you see 

 no proof of anything more than ' Glaciers smoothing the 

 sides a little.' I saw proof of enormous removal of stuff, 

 in moraines everywhere, and no doubt had we gone down 

 the valley we should have carried old glacial detritus to its 

 mouth. As to your ' seeing no proof,' I do not see the 

 force of this unless you have made a study of glacier action ; 

 a non-botanist ' sees no proof ' of Ruscus being allied to 

 Asparagus ! You have not lived alongside glaciers for 

 months and watched day by day what they do and what 

 they must have done. 



I am very stubborn about Greenland and have asked 

 Dyer to review the subject. Certainly Platanthera hyper- 

 lorea is European, if books are to be trusted. You make 

 no allowance for the great rarity in America of so many 

 Greenlandic plants. I mean such as just cross Baffin's 

 Bay, or turn up in one or two places in America. 



