Although Mountains May Guide Migrations, The Plains

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.

In America The Most Widespread Type Of Forest Is The Evergreen Coniferous Woodland Of The North.

The Coast Of British Columbia Was One Of The Three Chief Centers Of Aboriginal America.

From First To Last The Civilization Of America Has Been Bound Up With Its Physical Environment.

Geologists Are Rapidly Becoming Convinced That The Mammals Spread From Their Central Asian Point Of Origin Largely Because Of Great Variations In Climate.