

^/</</**x^/, 



THE 



AMERICAN JOURNAL OF SCIENCE 



[THIRD SERIES.] 



Art. XLYI. — On New England and the Upper Mississippi 

 basin in the Glacial period ; by James D. Dana. 



Since the publication, in this Journal, of Prof. G. F. 

 Wright's paper on the Unity of the Glacial epoch, nearly a 

 year since,* this subject has been much discussed in the scien- 

 tific journals of the country, and with some interesting develop- 

 ments besides those within the purpose of the writers. 



First. It has been shown that there are good working geol- 

 ogists on each side of the question. 



Secondly. It has been made manifest that the advocates of 

 unity are mainly the geologists that have investigated eastern 

 glacial regions in the country, and especially New England, 

 while the advocates of two Glacial epochs are chiefly those 

 whose glacial studies have been in more western regions. 



The writer, who has thus far taken no part in the recent 

 discussion, here states that he has found in his geological ex- 

 plorations, which have been extensive over New England, the 

 State of Maine excepted, no facts that require for their explana- 

 tion an appeal to two glacial epochs, and none that has even 

 suggested the idea. 



Thirdly. The presentation of arguments on the side of 

 unity has been moderate in tone and free from dogmatism. 

 Among geologists on the other side, great .confidence in the 

 obvious facts has given occasion to expressions almost of accom- 

 plished triumph for the two- epoch theory. 



* Volume xliv, page 351. 



Am. Jour. Sci.— Third Series, Yol. XLVI, No. 275.— Nov., 1893. 

 23 



