Origin of Species Variorum

→ free intercrossing will wholly stop 1859 1860 1861 1866 1869

if the individuals be allowed freely to intercross, 1872

→ work. 1859 1860 1861 1866 1869

work will completely fail. 1872

→ a large amount of crossing with inferior animals. 1859 1860 1861 1866 1869

that there is no separation of selected individuals. 1872

→ as might be, natural selection will always tend to preserve 1859 1860 1861 1866

natural selection will always tend to preserve 1869

OMIT 1872

→ so as better to fill up the unoccupied place. 1859 1860 1861 1866 1869

will tend to be preserved. 1872

→ then 1859 1861

then if natural selection be modifying and improving a species in the several districts, there will be intercrossing with the other individuals of the same species on the confines of each. 1860

then, 1866 1869 1872

↑ 2 blocks not present in 1859 1860 1861 1866; present in 1869 1872

if the same species undergoes modification in different parts, the newly-formed varieties will intercross on the confines of each district. But we shall see in the seventh chapter that intermediate varieties, inhabiting an intermediate district, whether the result of the crossing of other varieties, or originally formed with an intermediate character, will in the long run generally be supplanted by one of the varieties on either hand.

→ physical conditions 1861 1866

conditions 1859

physical conditions at least 1860

→ most affect those animals 1859 1860 1861 1866

affect those animals most 1869

chiefly affect those animals 1872

→ so that whatever intercrossing took place would be chiefly between 1859 1860 1861 1866

and afterwards spread, so that the crossing would be chiefly between 1869

and afterwards spread, so that 1872

some definite object, and →free intercrossing will wholly stop his →work. But when many men, without intending to alter the breed, have a nearly common standard of perfection, and all try to

procure

get

and breed from the best animals,

~~much~~

much

improvement

~~and modification~~

and modification

surely but slowly

follows

from this unconscious process of selection, notwithstanding →a large amount of crossing with inferior animals. Thus it will be

under

nature; for within a confined area, with some place in

the natural

its

polity not

perfectly

occupied,

occupied

→as might be, natural selection will always tend to preserve all the individuals varying in the right direction, though in different degrees, →so as better to fill up the unoccupied place. But if the area be

very large,

large,

its several districts will almost certainly present different conditions of life; and →then if natural selection be modifying and improving a species in the several districts, there will be intercrossing with the other individuals of the same species on the confines of each. ↑ And in this case the effects of intercrossing can hardly be

coun-

....

terbalanced

counterbalanced

by natural selection always tending to modify all the individuals in each district in exactly the same manner to the conditions of each; for in a continuous area, the →physical conditions will generally graduate away insensibly from one district to another.

~~The~~

The

Intercrossing

intercrossing

will →most affect those animals which unite for each

birth

birth,

and

which

wander much, and which do not breed at a very quick rate. Hence

with

animals of this nature, for