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.

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

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.

The whole history of life is a record of cycles.

In America the most widespread type of forest is the evergreen coniferous woodland of the north.

No part of the world can be truly understood without a knowledge of its garment of vegetation, for this determines not only the nature of the animal inhabitants but also the occupations of the majority of human beings.

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.