"The species are the work of the divine hand, the genera are the work of reason."

"All species of the same genus form a natural group, and all genera of the same order form a natural group."

"The whole system of nature is nothing but a system of sexual generation."

"The greatest pleasure of a gardener is to survey his work, and to admire the result of his own industry."

"The whole earth is a garden, and man is its gardener."