342 LOUIS AGASS1Z. 



FROM DR. BUCKLAND. 



OXFORD, July 22, 1842. 



. . . You will, I am sure, rejoice with me 

 at the adhesion of C. Darwin to the doctrine 

 of ancient glaciers in North Wales, of which I 

 send you a copy, and which was communicated 

 to me by Dr. Tritten, during the late meeting 

 at Manchester, in time to be quoted by me 

 versus Murchison, when he was proclaiming 

 the exclusive agency of floating icebergs in 

 drifting erratic blocks and making scratched 

 and polished surfaces. It has raised the gla- 

 cial theory fifty per cent., as far as relates to 

 glaciers descending inclined valleys ; but Hop- 

 kins and the Cantabrigians are still as obsti- 

 nate as ever against allowing the power of ex- 

 pansion to move ice along great distances on 

 horizontal surfaces. . . . 



The following is the letter referred to above. 



C. DARWIN TO DR. TRITTEN. 



Yesterday (and the previous days) I had 

 some most interesting work in examining the 

 marks left by extinct glaciers. I assure you, 

 an extinct volcano could hardly leave more 

 evident traces of its activity and vast powers. 



