The species and the genus are always the work of nature [i.e. specially created]; the variety mostly that of circumstance; the class and the order are the work of nature and art.

As one sits here in summertime and listens to the cuckoo and all the other bird songs, the crackling and buzzing of insects, as one gazes at the shining colors of flowers, doth one become dumbstruck before the Kingdom of the Creator.

There are as many species as the infinite being created diverse forms in the beginning, which, following the laws of generation, produced many others, but always similar to them: therefore there are as many species as we have different structures before us today.

To live by medicine is to live horribly.

Nature does not proceed by leaps.

Of what use are the great number of petrifactions, of different species, shape and form which are dug up by naturalists? Perhaps the collection of such specimens is sheer vanity and inquisitiveness. I do not presume to say; but we find in our mountains the rarest animals, shells, mussels, and corals embalmed in stone, as it were, living specimens of which are now being sought in vain throughout Europe. These stones alone whisper in the midst of general silence.

Botany is based on fixed genera.