America forms the longest and straightest bone in the earth's skeleton.

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.

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

Although mountains may guide migrations, the plains are the regions where people dwell in greatest numbers.

The Negro, however, has been tested on an extensive scale.

As a matter of fact, an ordinary desert supports a much greater variety of plants than does either a forest or a prairie.

Thus the races, though alike in their physical response to climate, may possibly be different in their mental response because they have approached America by different paths.