Although mountains may guide migrations, the plains are the regions where people dwell in greatest numbers.

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

The whole history of life is a record of cycles.

With every throb of the climatic pulse which we have felt in Central Asia,, the centre of civilisation has moved this way and that. Each throb has sent pain and decay to the lands whose day was done, life and vigour to those whose day was yet to be.

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

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.

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.