PREHISTORIC MAN IN THE NEW WORLD 
wandered across into North America; but if so, they per- 
ished without leaving any traces that have so far been 
definitely identified. The American Indians, the only race 
known certainly ever to have lived in the Western Hemi- 
sphere before the white man came, seem not to have arrived 
there until toward, or perhaps even after, the close of the 
Ice Age. 
We must not suppose, however, that they invaded the 
New World all at once, in a large body. On the contrary, 
the process must have been a very gradual one, going on 
through several thousands of years. It was only after 
northeastern Siberia itself had been occupied by man that 
little groups began drifting over into North America. 
Whether the land connection between the latter and Asia 
was still in existence when this first occurred, or whether 
it had already sunk beneath the sea, we do not know. But 
however the first man in America arrived, whether on foot 
or by canoe, it seems quite certain that he reached his 
new home as a mere savage—a hunter and food-gatherer. 
He had learned how to make various forms of stone tools, 
but we can not say whether he yet had the bow and arrow. 
The dog also no doubt accompanied him to his new home. 
Once settled in the New World, the ancestors of the 
American Indians gradually multiplied and spread out 
over more and more territory. In this way the whole of 
the Western Hemisphere was slowly peopled. 
It was not, however, until long afterward that the first 
beginnings of settled agricultural life began to appear in 
various favorable localities. Several reasons render it 
practically certain that the ancestors of the American 
Indians did not bring with them any cultivated plants 
from the Old World. Those which we find grown later are 
of distinctively American species. 
Hunting and food-gathering first began to give place to 
food-growing and a more settled life probably in the high 
plateau areas of the western portions of both continents. 
In these regions, elevation and a somewhat dry climate 
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