The man who has grit enough to bring about the afforestation or the irrigation of a country is not less worthy of honor than its conqueror.

The most powerful factors in the world are clear ideas in the minds of energetic men of good will.

The Doctrine of Evolution states the fact that the present is the child of the past and the parent of the future.

A prolonged war in which a nation takes part is bound to impoverish the breed, since the character of the breed depends on the men who are left.

All Nature bristles with the marks of interrogation-among the grass and the petals of flowers, amidst the feathers of birds and the hairs of mammals, on mountain and moorland, in sea and sky-everywhere. It is one of the joys of life to discover those marks of interrogation, these unsolved and half-solved problems and try to answer their questions.

The man who has grit enough to bring about the afforestation or the irrigation of a country is not less worthy of honor than its conqueror.

There is no counting the unsolved problems of Natural History.