Although farming of any sort was almost as impossible in the plains as in the dry regions of winter rains farther west, the abundance of buffaloes made life much easier in many respects.

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.

From first to last the civilization of America has been bound up with its physical environment.

Year by year we are learning that in this restless, strenuous American life of ours vacations are essential.

Geologists are rapidly becoming convinced that the mammals spread from their central Asian point of origin largely because of great variations in climate.

Except on their southern borders the great northern forests are not good as a permanent home for man.

Although farming of any sort was almost as impossible in the plains as in the dry regions of winter rains farther west, the abundance of buffaloes made life much easier in many respects.