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

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

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

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.

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

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.

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