With mammals the male appears to win the female much more through the law of battle than through the display of his charms.

After my return to England it appeared to me that by following the example of Lyell in Geology, and by collecting all facts which bore in any way on the variation of animals and plants under domestication and nature, some light might perhaps be thrown on the whole subject.

I see no good reasons why the views given in this volume should shock the religious views of anyone.

Not one change of species into another is on record ... we cannot prove that a single species has been changed.

Why does man regret, even though he may endeavour to banish any such regret, that he has followed the one natural impulse, rather than the other; and why does he further feel that he ought to regret his conduct? Man in this respect differs profoundly from the lower animals.

We cannot fathom the marvelous complexity of an organic being; but on the hypothesis here advanced this complexity is much increased. Each living creature must be looked at as a microcosm--a little universe, formed of a host of self-propagating organisms, inconceivably minute and as numerous as the stars in heaven.

It is a fatal fault to reason whilst observing, though so necessary beforehand and so useful afterwards.