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.

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

A journey of four hundred and thirty miles can be made in any part of the United States, but in Turkey it takes as many days.

We are learning, too, that the love of beauty is one of Nature's greatest healers.

Fertile soil, level plains, easy passage across the mountains, coal, iron, and other metals imbedded in the rocks, and a stimulating climate, all shower their blessings upon man.

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

Man could not stay there forever. He was bound to spread to new regions, partly because of his innate migratory tendency and partly because of Nature's stern urgency.