Origin of Species Variorum

→ then, 1866 1869 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

↑ 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

→ same new variety. 1859 1860 1861 1866

new variety living together in the same place. 1869

new variety would chiefly cross together. 1872

→ same variety, as the 1859 1860 1861 1866

OMIT 1869 1872

→ with other varieties 1859 1860 1861 1866

OMIT 1869 1872

→ in the case of slow-breeding 1859 1860 1861 1866

in the case of 1869

with 1872

→ unite 1859 1860 1861 1866 1872

breed slowly and unite 1869

→ we 1859 1860 1861 1866 1869

and which do not propagate rapidly, we 1872

→ overrate 1859 1860 1861 1866

assume that 1869

assume that free intercrossing would always eliminate 1872

→ intercrosses in retarding 1859 1860 1861 1866

OMIT 1869 1872

→ for 1859 1860 1861 1866 1872

will always be immediately overpowered by free intercrossing; for 1869

→ a considerable catalogue 1859 1860 1861 1866

a considerable body 1869

forward a considerable body 1872

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

instance,

instance

birds, varieties will generally be confined to separated countries; and this I

believe

find

to be the case.

With

hermaphrodite organisms which cross only occasionally, and likewise

with

animals which unite for each birth, but which wander little and

~~which~~

which

can increase at a

~~very~~

very

rapid rate, a new and improved variety might be quickly formed on any one spot, and might there maintain itself in a

body

body,

→so that whatever intercrossing took place would be chiefly between the individuals of the →same new variety. A local variety when once thus formed might subsequently slowly spread to other districts. On

this

the above

principle, nurserymen always prefer

saving

getting

seed from a large body of

plants,

plants