I am a firm believer, that without speculation there is no good and original observation.

During my second year at Edinburgh [1826-27] I attended Jameson's lectures on Geology and Zoology, but they were incredible dull. The sole effect they produced on me was the determination never as long as I lived to read a book on Geology.

If man had not been his own classifier, he would never have thought of founding a separate order for his own reception.

But Geology carries the day: it is like the pleasure of gambling, speculating, on first arriving, what the rocks may be; I often mentally cry out 3 to 1 Tertiary against primitive; but the latter have hitherto won all the bets.

I find in the domestic duck that the bones of the wing weigh less and the bones of the leg more, in proportion to the whole skeleton, than do the same bones in the wild duck; and this change may be safely attributed to the domestic duck flying much less, and walking more, than its wild parents.

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

It's not the strongest, but the most adaptable that survive.