JAMES DWIGHT DANA. 615 
Acadian upturning took place on the ocean border, and the Appala- 
chian was not far distant from it, Arkansas, moreover, added to the 
extent of the belt of disturbance. Under such circumstances devasta- 
tion of the sea border and the low lying land of the period, the 
destruction of their animals and plants, would have been a sure result. 
The survivors within a long distance of the coast line would have been 
few. ‘The same waves would have swept over European land and seas, 
and there found coadjutors for new strife in earthquake waves of 
European origin. ‘These times of catastrophe may have continued in 
America through half of the following Triassic period, for fully two- 
thirds of the Triassic period are represented by rocks and fossils on 
the Atlantic border” (p. 736). 
Thus the course of the evolution of the life on its surface 
was in no small way dependent upon the gradual contracting of 
a cooling globe. 
Not only did Dana take this broad and comprehensive view 
of the whole system of geological phenomena, but he made a 
thorough and particular study of several of the more difficult 
problems of American geology ; among them may be named the 
interpretation of the glacial phenomena over New England and 
the classification of the period for North America—the solution 
of the ‘‘Taconic”’’ controversy, and the associated questions of 
metamorphism and mountain building. 
When the first edition of the Manual was issued (1863) there 
was far from unaniminity of opinion among American geologists 
as to the agency by which “drift”? gravel and bowlders had been 
spread over the surface of the more northern states of the Union. 
Dana interpreted the “drift” and the striations on the sur- 
face of the rock to be evidences of glaciation, and he was an 
earnest advocate of the theory of a great continental glacier, as 
opposed to the iceberg theory. Although few of the present 
generation have ever held another opinion, some of us will 
remember the strenuous defense of the iceberg theory so lately 
as the meeting of the American Association of Science at Mont- 
real. Professor Dana not only opposed that theory from the 
beginning, but by his indefatigable personal studies of the sur- 
face topography and markings in the Connecticut Valley, and 
