The facts will eventually test all our theories, and they form, after all, the only impartial jury to which we can appeal.

As long as men inquire, they will find opportunities to know more upon these topics than those who have gone before them, so inexhaustibly rich is nature in the innermost diversity of her treasures of beauty, order and intelligence.

I now never make the preparations for penetrating into some small province of nature hitherto undiscovered without breathing a prayer to the Being who hides His secrets from me only to allure me graciously on to the unfolding of them.

I will frankly tell you that my experience in prolonged scientific investigations convinces me that a belief in God-a God who is behind and within the chaos of vanishing points of human knowledge-adds a wonderful stimulus to the man who attempts to penetrate into the regions of the unknown.

Select such subjects that your pupils cannot walk out without seeing them. Train your pupils to be observers, and have them provided with the specimens about which you speak. If you can find nothing better, take a house-fly or a cricket, and let each one hold a specimen and examine it as you talk.

Nature brings us back to absolute truth whenever we wander.

Embryology furnishes, also, the best measure of true affinities existing between animals.