446 LOUIS AGASSIZ. 



tion, far from presenting itself more simply 

 here, is complicated by peculiarities never 

 brought to my notice in Europe. Happily 

 for me, Mr. Desor, who had been in Scan- 

 dinavia before joining me here, called my at- 

 tention at once to certain points of resem- 

 blance between the phenomena there and those 

 which I had seen in the neighborhood of Bos- 

 ton. Since then, we have made several ex- 

 cursions together, have visited Niagara, and, 

 in short, have tried to collect all the spe- 

 cial facts of glacial phenomena in America. 

 Within a few days, however, I have come by 

 chance upon something quite extraordinary 

 and unexpected, which complicates the ques- 

 tion anew. You are, no doubt, aware that 

 the whole rocky surface of the ground here 

 is polished. I do not think that anywhere in 

 the world there exist polished and rounded 

 rocks in better preservation or on a larger 

 scale. Here, as elsewhere, erratic debris are 

 scattered over these surfaces, scratched peb- 

 bles impacted in mud, forming unstratified 

 masses mixed with and covered by large er- 

 ratic boulders, more or less furrowed or 

 scratched, the upper ones being usually an- 

 gular and without marks. The absence of 

 moraines, properly so-called, in a country so 



