History in its broadest aspect is a record of man's migrations from one environment to another.

The evidence points to central Asia as man's original home, for the general movement of human migrations has been outward from that region and not inward.

In fact, the history of North America has been perhaps more profoundly influenced by man's inheritance from his past homes than by the physical features of his present home.

The geysers and hot springs of the Yellowstone are another proof of recent volcanic activity.

For the source of any characteristic so widespread and uniform as this adaptation to environment we must go back to the very beginning of the human race.

Curiously enough man's body and his mind appear to differ in their climatic adaptations.