Characteristics cling to families.

It is notorious that the same discovery is frequently made simultaneously and quite independently, by different persons. Thus, to speak of only a few cases in late years, the discoveries of photography, of electric telegraphy, and of the planet Neptune through theoretical calculations, have all their rival claimants. It would seem, that discoveries are usually made when the time is ripe for them - that is to say, when the ideas from which they naturally flow are fermenting in the minds of many men.

All male animals, including men, when they are in love, are apt to behave in ways that seem ludicrous to bystanders.

It is always the case with the best work, that it is misrepresented, and disparaged at first, for it takes a curiously long time for new ideas to become current, and the older men who ought to be capable of taking them in freely, will not do so through prejudice.

The publication in 1859 of the Origin of Species by Charles Darwin made a marked epoch in my own mental development, as it did in that of human thought generally. Its effect was to demolish a multitude of dogmatic barriers by a single stroke, and to arouse a spirit of rebellion against all ancient authorities whose positive and unauthenticated statements were contradicted by modern science.

Well-washed and well-combed domestic pets grow dull; they miss the stimulus of fleas.

What nature does blindly, slowly and ruthlessly, man may do providently, quickly, and kindly. As it lies within his power, so it becomes his duty to work in that direction.