438 THE ICE AGE IN NORTH AMERICA. 



while some of them, like the horse, were admirably adapted 

 to the present conditions, as is shown by their rapid increase 

 since their introduction after the discovery of America by 

 the whites. In a succeeding chapter we shall also see that 

 man himself participated in this struggle with the new con- 

 ditions introduced by the Glacial period on this continent, 

 and that, in company with the mammoth, walrus, and other 

 arctic species, he followed up the retreating ice both upon 

 the Atlantic coast and in the Mississippi Valley. Whether, 

 like some of his companions, he was unsuccessful in the con- 

 test is not certain, though there is much to be said in favor 

 of the theory that the Eskimos of the north are the lineal 

 descendants of the preglacial men whose implements are 

 found in New Jersey, Ohio, and Minnesota. Much also may 

 be said to support the theory, alluded to by Professor Clay- 

 pole, connecting the traditions of the destruction of large 

 portions of the human race by a flood with the extermination 

 of species naturally brought about by the conditions accom- 

 panying the floods which closed the Glacial period. 



It is interesting to observe, also, that insects as well as 

 plants and the larger animals were compelled to reckon with 

 the Glacial period. They, too, participated in the southern 

 migration enforced by the advancing ice, and also shared in the 

 vicissitudes of its final retreat, compelling them to escape from 

 the warmer belt of climate which again advanced upon them 

 from the south. Like the forms of arctic and Alpine vegeta- 

 tion, a portion of the insects also took to the mountains, 

 where they still remain, as living witnesses to the reality of 

 the Glacial period. The summits of the White Mountains 

 are characterized by Alpine species of insects, one of which is 

 thus described by Mr. Samuel Scudder : 



But even the narrow limit of the Alpine zone of the White 

 Mountains claims for its own a single butterfly, which probably 

 has a more restricted range than any other in the world. One 

 may search the season through over the comparatively vast and 

 almost equally barren elevations within the sub- Alpine district 

 of the White Mountains and fail to discover more than here 



