Life itself is a school, and Nature always a fresh study.

The primary rocks, ... I regard as the deposits of a period in which the earth's crust had sufficiently cooled down to permit the existence of a sea, with the necessary denuding agencies,-waves and currents,-and, in consequence, of deposition also; but in which the internal heat acted so near the surface, that whatever was deposited came, matter of course, to be metamorphosed into semi-plutonic forms, that retained only the stratification.

Problems are only opportunities with thorns on them.

The sky is full of tokens which speak to the intelligent.

All geologic history is full of the beginning and the ends of species-of their first and last days; but it exhibits no genealogies of development.

That special substance according to whose mass and degree of development all the creatures of this world take rank in the scale of creation, is not bone, but brain.

The footprint of the savage traced in the sand is sufficient to attest the presence of man to the atheist who will not recognize God, whose hand is impressed upon the entire universe.