J. W. Dawson on the Drift. 235 
only the siding motion of glaciers that can polish or erode sur- 
faces, and that any internal changes resulting from the mere 
ried boulders for hundreds of miles, and left them on points as 
high as those they were taken from. On the Montreal Mountain 
at a height of 600 feet above the sea, are huge boulders of feldspar 
rom the Laurentide hills, which must haveebeen carried from 
50 to 200 miles from points of scarcely greater elevation, and 
over a valley in which the strie are in a direction nearly at right 
angles with that of the probable driftage of the boulders. Quite 
as striking examples occur in many parts of this country. Itis 
also to be observed that boulders, often of large size, occur scat- 
tered through the marine stratified clays and sands containing sea 
shells; and whatever views ma entertained as to other boul- 
5. The peat deposits with fir roots, found below the boulder 
clay in caer ees, the remains of plants and land snails in 
the marine clays of the Ottawa, and the shells of the St. Law- 
Tence clays and sands, show that the sea, at the period in question, 
Aad much the temperature of the present Arctic currents of our 
Coasts, and that the land was not covered with ice, but suppo’ 
Vegetation similar to that of Labrador and the north shore of 
the St Lawrence at present. This evidence refers not to the 
Jater period of the Mammoth and Mastodon, when the re-eleva- 
tion was perhaps nearly complete, but to the earlier period con- 
