VI 
THE OLD ICE-FLOOD 
I 
E was a bold man who first conceived the idea 
of the great continental ice-sheet which in 
Pleistocene times covered most of the northern part 
of the continent, and played such a part in shaping 
the land as we know it. That bold man was Agas- 
siz, who, however, was not bold enough to accept 
the theory of evolution as propounded by Darwin. 
The idea of the great glacier did not conflict with 
Agassiz’s religious predilections, and the theory of 
evolution did. It was a bold generalization, this of 
the continental ice-sheet, one of the master-strokes 
of the scientific imagination. It was about the year 
1840 that Agassiz, fresh from the glaciersof the Alps, 
went to Scotland looking for the tracks of the old 
glaciers, and he found them at once when he landed 
near Glasgow. We can all find them now on almost 
every walk we take to the fields and hills; but until 
our eyes are opened, how blind we are to them! 
We are like people who camp on the trail of an 
army and never suspect an army has passed, though 
the ruts made by their wagons and artillery and 
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