Origin of Species Variorum

→ varieties of the same kind 1859 1860 1861 1866 1869

the individuals of each variety 1872

→ I have already attempted to show that 1859 1860 1861 1866

as already stated 1869

as already stated, 1872

→ OMIT 1861 1866

I am convinced that 1859 1860

of time, 1869 1872

→ If there exist 1859 1860 1861 1866 1869

With respect to 1872

→ which never 1859 1860 1861 1866 1869

extremely low in the scale, which do not propagate sexually, nor conjugate, and which cannot possibly 1872

→ as long as their 1859 1860 1861 1866 1869

under the same 1872

→ remain the same, 1859 1860 1861 1866 1869

OMIT 1872

→ destroying any which depart 1859 1860 1861 1866 1869

which will destroy any individuals departing 1872

→ but if their 1859 1860 1861 1866 1869

If the 1872

→ process of 1859 1860 1861 1866

changes effected through 1869

modification of 1872

→ natural 1859 1860 1861 1866 1869

species through natural 1872

→ in a great degree 1859 1860 1861 1866

almost 1869 1872

→ individuals of a varying species throughout the area 1859 1860 1861 1866

varying individuals of the same species 1869 1872

→ same species, which othewise would have inhabited the surrounding and differently circumstanced 1866

same species, which otherwise would have inhabited the surrounding and differently circumstanced 1859 1860 1861

surrounding 1869 1872

long remain distinct, from haunting different stations, from breeding at slightly different seasons, or from →varieties of the same kind preferring to pair together.

Intercrossing plays a very important part in nature

keeping the individuals of the same species, or of the same variety, true and uniform in character. It will obviously thus act far more efficiently with those animals which unite for each birth;

but,

but

→I have already attempted to show that we have reason to believe that occasional intercrosses take place with all animals and

~~with all~~

with all

plants. Even if these take place only at long

intervals

intervals,

→OMIT the young thus produced will gain so much in vigour and fertility over the offspring from long-continued self-fertilisation, that they will have a better chance of surviving and propagating their kind; and thus, in the long run, the influence of

crosses,

intercrosses,

even at rare intervals, will be great. →If there exist organic beings →which never intercross, uniformity of character can be retained

amongst

them

them,

→as long as their conditions of

life,

life

→remain the same, only through the principle of

inheritance

inheritance,

and through natural selection →destroying any which depart from the proper

type.

type;

→but if their conditions of life change and

the

they

form undergoes

undergo

modification, uniformity of character can be given to

the

their

modified offspring, solely by natural selection preserving

similar

the same

favourable variations.

Isolation, also, is an important element in the →process of →natural selection. In a confined or isolated area, if not very large, the organic and inorganic conditions of life will generally be →in a great degree uniform; so that natural selection will tend to modify all the →individuals of a varying species throughout the area in the same

manner.

~~relation~~

~~the~~

~~same~~

~~conditions.~~

Intercrossing

~~also,~~

with the

inhabitants

individuals

of the →same species, which othewise would have inhabited the surrounding and differently circumstanced