History in its broadest aspect is a record of man's migrations from one environment to another.

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

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.

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

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

The human organism inherits so delicate an adjustment to climate that, in spite of man's boasted ability to live anywhere, the strain of the frozen North eliminates the more nervous and active types of mind.

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