Except On Their Southern Borders

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

It Will Be A Vast Boon To Mankind When We Learn To Prophesy The Precise Dates When Cycles Of Various Kinds Will Reach Definite Stages.

Year By Year We Are Learning That In This Restless, Strenuous American Life Of Ours Vacations Are Essential.

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

As A Matter Of Fact, An Ordinary Desert Supports A Much Greater Variety Of Plants Than Does Either A Forest Or A Prairie.