"Ah," said the elder and more thoughtful of the pair, "if they were only reindeer!" When domesticated, the reindeer yields milk as well as food, though large numbers are needed to keep the community in comfort.

Otherwise hunting and fishing must serve to eke out the larder.

Miserable indeed are the tribes or rather remnants of tribes along the Siberian tundra who have no reindeer.

On the other hand, if there are plenty of wild reindeer, as amongst the Koryaks and some of the Chukchis, hunting by itself suffices.
* * * * * Let us now pass on from the Eurasian northland to what is, zoologically, almost its annexe, North America; its tundra, for example, where the Eskimo live, being strictly continuous with the Asiatic zone.

Though having a very different fauna and flora, South America presumably forms part of the same geographical province so far as man is concerned, though there is evidence for thinking that he reached it very early.
Until, however, more data are available for the pre-history of the American Indian, the great moulding forces, geographical or other, must be merely guessed at.