A grain in the balance will determine which individual shall live and which shall die - which variety or species shall increase in number, and which shall decrease, or finally become extinct.

The question of whether there exists a Creator and Ruler of the Universe has been answered in the affirmative by some of the highest intellects that have ever existed.

Thomson's views on the recent age of the world have been for some time one of my sorest troubles.

Nothing can be more improving to a young naturalist, than a journey in a distant country.

The instruction at Edinburgh was altogether by lectures, and these were intolerably dull, with the exception of those on chemistry.

I could show fight on natural selection having done and doing more for the progress of civilization than you seem inclined to admit. Remember what risk the nations of Europe ran, not so many centuries ago of being overwhelmed by the Turks, and how ridiculous such an idea now is! The more civilised so-called Caucasian races have beaten the Turkish hollow in the struggle for existence. Looking to the world at no very distant date, what an endless number of the lower races will have been eliminated by the higher civilized races throughout the world.

On the theory of natural selection we can clearly understand the full meaning of that old canon in natural history, “Natura non facit saltum.” This canon, if we look only to the present inhabitants of the world, is not strictly correct, but if we include all those of past times, it must by my theory be strictly true.