Origin of Species Variorum

→ it is difficult, perhaps impossible, to bring forward one case of the hybrid offspring of two animals clearly distinct being themselves 1859 1860 1861 1866 1869

hardly any cases have been ascertained with certainty of hybrids from two quite distinct species of animals being 1872

→ from 1859 1860 1861 1866 1869

in species. From 1872

→ and of some other domestic animals, there is great probability in this hypothesis, 1866 1869

I think there is some probability in this hypothesis, 1859 1860 1861

and of some other domestic animals, this conclusion is probably quite correct, 1872

→ to each other, though it is unsupported by a single experiment. 1866 1869

together, though it is unsupported by a single experiment. 1859 1860 1861

to each other. 1872

→ seems to me 1859 1860 1861 1866 1869

would be 1872

→ becoming 1859 1860 1861 1866 1869

not having become 1872

→ these species having 1859 1860 1861 1866 1869

— these species presenting certain 1872

→ in certain respects, 1859 1860 1861 1866 1869

OMIT 1872

→ in most other respects to 1859 1860 1861 1866 1869

OMIT 1872

→ the 1859 1860 1861 1866 1869

in most respects; — the occasional re-appearance of the 1872

→ black marks occasionally appearing 1861 1866 1869

marks occasionally appearing 1859 1860

black marks 1872

→ the 1859 1860 1861 1866 1869

— and lastly, the 1872

→ we may safely conclude 1861 1866 1869 1872

I can feel no doubt 1859 1860

→ Columba 1859 1860 1861 1866 1869

rock-pigeon or Columba 1872

→ C. livia, or the rock-pigeon, 1859 1860 1861 1866 1869

the wild C. livia 1872

on the most distinct breeds. Now, → it is difficult, perhaps impossible, to bring forward one case of the hybrid offspring of two animals clearly distinct being themselves perfectly fertile. Some authors believe that long-continued domestication eliminates this strong tendency to

sterility

sterility:

→from the history of the

dog

dog,

→and of some other domestic animals, there is great probability in this hypothesis, if applied to species closely related →to each other, though it is unsupported by a single experiment. But to extend

the hypothesis

so far as to suppose that species, aboriginally as distinct as carriers, tumblers, pouters, and fantails now are, should yield offspring perfectly

fertile,

fertile

inter se , →seems to me rash in the extreme.

From these several reasons, namely,

— the

the

improbability of man having formerly

made

got

seven or eight supposed species of pigeons to breed freely under domestication;

— these

these

supposed species being quite unknown in a wild state, and their →becoming

anywhere

nowhere

feral; →these species having very abnormal

characters,

characters

→in certain respects, as compared with all other Columbidæ, though so like →in most other respects to the

rock-pigeon

rock-pigeon;

→the blue colour and various →black marks occasionally appearing in all the breeds, both when kept pure and when crossed; →the mongrel offspring being perfectly fertile; — from these several reasons, taken together, →we may safely conclude that all our domestic breeds

are

have

descended from the →Columba livia with its geographical sub-species.

In favour of this view, I may add,

first,

firstly,

that →C. livia, or the rock-pigeon, has been found capable of domestication in Europe and in India; and that it agrees in habits and in a great number of points of structure with all the domestic breeds. Secondly,

that, although

although

an English carrier or

short-faced

a short-faced

tumbler differs immensely in certain