John Ray - Ray's Definition of Species

Ray's Definition of Species

Ray was the first person to produce a biological definition of what a species is. This definition comes in the 1686 History of plants:

"... no surer criterion for determining species has occurred to me than the distinguishing features that perpetuate themselves in propagation from seed. Thus, no matter what variations occur in the individuals or the species, if they spring from the seed of one and the same plant, they are accidental variations and not such as to distinguish a species... Animals likewise that differ specifically preserve their distinct species permanently; one species never springs from the seed of another nor vice versa".

Read more about this topic:  John Ray

Famous quotes containing the words ray, definition and/or species:

    How false is the conception, how frantic the pursuit, of that treacherous phantom which men call Liberty: most treacherous, indeed, of all phantoms; for the feeblest ray of reason might surely show us, that not only its attainment, but its being, was impossible. There is no such thing in the universe. There can never be. The stars have it not; the earth has it not; the sea has it not; and we men have the mockery and semblance of it only for our heaviest punishment.
    John Ruskin (1819–1900)

    No man, not even a doctor, ever gives any other definition of what a nurse should be than this—”devoted and obedient.” This definition would do just as well for a porter. It might even do for a horse. It would not do for a policeman.
    Florence Nightingale (1820–1910)

    Any reading not of a vicious species must be a good substitute for the amusements too apt to fill up the leisure of the labouring classes.
    James Madison (1751–1836)