Origin of Species Variorum

→ not of differences in the reproductive system. 1859 1860 1861 1866

that they have not been long exposed to uniform conditions of life. 1869 1872

↑ 1 blocks not present in 1859 1860 1861; present in 1866 1869 1872

Nor should it be forgotten that long-continued domestication apparently tends to eliminate sterility, and is therefore little likely to induce this same quality.

→ In 1859 1860 1861

Excluding the subject of fertility, in 1866

→ the facts briefly 1859 1860

although we are profoundly ignorant in every case of the precise cause of sterility, the facts briefly 1861

although we are profoundly ignorant in every case of the precise cause of the sterility of first crosses and of hybrids, the facts briefly 1866

although we are profoundly ignorant of the precise cause of the sterility of first crosses and of hybrids, the facts 1869

although we are as ignorant of the precise cause of the sterility of first crosses and of hybrids as we are why animals and plants removed from their natural conditions become sterile, yet the facts 1872

→ to, but even rather to support the view, that there is no fundamental distinction between species and varieties. 1859 1860

to, but even rather to support in some respects the view, that there is no fundamental distinction between species and varieties. 1861

to the view, that there is no fundamental distinction between species and varieties. 1866

to the belief that varieties and species are not fundamentally different. 1869

to the belief that species aboriginally existed as varieties. 1872

fertile. Nor is this

almost universal

nearly general

and perfect fertility surprising, when

it is

remembered

remember

how liable we are to argue in a circle with respect to varieties in a state of nature; and when we remember that the greater number of varieties have been produced under

domesti- cation

domestication

by the selection of mere external differences, and →not of differences in the reproductive system. ↑ →In all other

respects

respects,

~~excluding fertility,~~

excluding fertility,

there is

the

closest

general resemblance between hybrids and mongrels. Finally, then, →the facts briefly given in this chapter do not seem to me opposed →to, but even rather to support the view, that there is no fundamental distinction between species and varieties.