I seldom go into a natural history museum without feeling as if I were attending a funeral.

The smallest deed is better than the greatest intention.

It is the life of the crystal, the architect of the flake, the fire of the frost, the soul of the sunbeam. This crisp winter air is full of it.

Science sees the process of evolution from the outside, as one might a train of cars going by, and resolves it into the physical and mechanical elements, without getting any nearer the reason of its going by, or the point of its departure or destination.

In the printed page the only real things are the paper and the ink; the white spaces play the same part in aiding the eye to take in the meaning of the print as do the black letters.

Joy in the universe, and keen curiosity about it all - that has been my religion.

If you want to see birds, you must have birds in your heart.