Now when naturalists observe a close agreement in numerous small details of habits, tastes and dispositions between two or more domestic races, or between nearly-allied natural forms, they use this fact as an argument that all are descended from a common progenitor who was thus endowed; and consequently that all should be classed under the same species. The same argument may be applied with much force to the races of man.

The season of love is that of battle. The roots of these fights run deep.

The several difficulties here discussed, namely our not finding in the successive formations infinitely numerous transitional links between the many species which now exist or have existed; the sudden manner in which whole groups of species appear in our European formations; the almost entire absence, as at present known, of fossiliferous formations beneath the Silurian strata, are all undoubtedly of the gravest nature.

One hand has surely worked throughout the universe.

What wretched doings come from the ardor of fame; the love of truth alone would never make one man attack another bitterly.

Man is developed from an ovule, about 125th of an inch in diameter, which differs in no respect from the ovules of other animals.

One general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die.