Evolution is written on the wings of butterflies.

I believe man... in the same predicament with other animals.

I am not the least afraid to die.

How odd it is that anyone should not see that all observation must be for or against some view if it is to be of any service!

Further on, he adds, that dogs, when feeling affectionate, lower their ears in order to exclude all sounds, so that their whole attention may be concentrated on the caresses of their master! Dogs have another and striking way of exhibiting their affection, namely, by licking the hands or faces of their masters.

If the country were open on its borders, new forms would certainly immigrate, and this also would seriously disturb the relations of some of the former inhabitants.

Who can explain why one species ranges widely and is very numerous, and why another allied species has a narrow range and is rare? Yet these relations are of the highest importance, for they determine the present welfare, and, as I believe, the future success and modification of every inhabitant of this world.

The very essence of instinct is that it's followed independently of reason.

Man is descended from a hairy, tailed quadruped, probably arboreal in its habits.

It is a cursed evil to any man to become as absorbed in any subject as I am in mine.