1841-42.] JAMES D. FORBES. 187 



les a pas encore. Ce sera Gressly on moi qui vous les auront fait 

 parvenir, afin cTapprendre de vous, si vous aviez quelque chose de 

 neuf dans ces genres. Vous irfobligerez infiniment en en faisant 

 une petite caisse et en me Tadressant avec vos oursins. Nous 

 determinerons cela en commim, et Gressly ou Desor vous renverra 

 prochainement le tout. 



Agreez, Monsieur, mes salutations tres empressees. 



Ls. AGASSIZ. 



Seldom has Agassiz written such an important scien- 

 tific letter, showing as it does his method of determining 

 species and establishing new genera. In it he anticipates 

 the criticism which has been made since, that he created 

 too many species ; for instance, of fossil fishes from the 

 flysck 1 of Claris, some of which were distorted by strong 

 lateral pressure. A larger number of specimens than 

 were then at his disposal have since proved his mistake. 



At the meeting of the British Association at Glasgow 

 during September, 1840, James D. Forbes, professor of 

 natural philosophy in the University of Edinburgh, took 

 such an interest in all the communications made by 

 Agassiz on the glacial question and the glaciers, that 

 Agassiz very politely tendered him an invitation to visit 

 him the next summer at his " Hotel des Neuchatelois." 



On the 8th of August, 1841, Agassiz, with his assist- 

 ants, again occupied their old and rather rough quarters 

 on the Aar glacier ; and there Forbes, accompanied by 

 a Scotch friend, Mr. Heath, was received as a 'welcome 

 guest. Agassiz was delighted to have a physician so 

 celebrated as Forbes to examine his observations. He 

 showed him everything - - all the experiments they were 



1 A lithologic term used in German Switzerland to designate a series of 

 strata belonging to the Tertiary Eocene. 



