THE TALE OF THE FISHES 



once widely distributed when all our lakes were cold 

 and pure and pebbly, but gradually becoming extinct 

 as the great glacier melted toward the north and the 

 waters in its wake grew warm. It is known to survive 

 in three New England lakes, Sunapee and Dan Hole 

 Pond in New Hampshire, and Flood's Pond in the 

 town of Otis, near Mt. Desert in Maine all three very 

 deep and excessively cold, and well stocked with the 

 native food of the saibling. In many other lakes it has 

 presumably been starved out and killed by rising tem- 

 perature, as has been the case in Europe, charrs having 

 become extinct in some waters, notably Loch Leven, 

 almost within the memory of living men. 



Changing conditions modify fish forms, and it was 

 suggested that this charr now known as the Salvelinus 

 alpinus aureolas from its golden hue, was the parent 

 type from which our charrs of the brook and lake differ- 

 entiated. The lake trout, however, can not be a deriv- 

 ative from this square-tailed fish, but is rather a variant 

 from some older fork-tailed stock, which, together with 

 the remote ancestors of the saibling group, is divergent 

 from a still earlier common primordial forbear a 

 theory strengthened by the discovery of fossil trout 



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