Origin of Species Variorum

→ in 1859 1860 1861 1866

will not have been much modified in 1869 1872

→ descendants of the parent-species will still resemble each other closely, for they will not have been modified. 1859 1860 1866

descendants of the parent species will still resemble each other closely, for they will not have been modified. 1861

forms; although in each the embryonic fore-limb will differ greatly from that in the adult. 1869

forms; although in each form the fore-limb will differ greatly in the adult state. 1872

→ long-continued exercise or use on the one hand, and disuse on the other, 1859 1860 1861

long-continued exercise or disuse 1866

moreover, long-continued use or disuse 1869

long-continued use or disuse 1872

→ in modifying an organ, such influence will mainly affect the mature animal, which has come to its 1859 1860 1861

had in modifying an organ, such influence will mainly affect the mature animal, which has come to its 1866

had in modifying the limbs or other parts of animals, this will chiefly or solely have affected them when mature and when they had to use their 1869

had in modifying the limbs or other parts of any species, this will chiefly or solely have affected it when nearly mature, when it was compelled to use its 1872

→ of activity and has 1859 1860 1861 1866

OMIT 1869 1872

→ be inherited 1859 1860 1861 1866

be transmitted to the offspring 1869

have been transmitted to the offspring 1872

→ remain unmodified, or 1859 1860 1861 1866

not 1869

not be modified, or 1872

→ be modified 1859 1860 1861 1866 1869

will be modified only 1872

→ in a lesser degree, by the effects of use and disuse. 1859 1860 1861 1866

or will be modified in a less degree. 1869

in a slight degree, through the effects of the increased use or disuse of parts. 1872

→ In certain cases 1859 1860 1861 1866

In other cases 1869

With some animals 1872

→ steps of variation might supervene, from causes of which we are wholly ignorant, 1859 1860 1861 1866

variations may have supervened 1869 1872

→ might be 1859 1860 1861 1866

may have been 1869 1872

→ case (as with the short-faced tumbler) 1859 1860 1861 1866

case, as we have seen with the short-faced tumbler, 1869

of these cases, 1872

→ parent-form. 1859 1860 1861 1866 1869

parent-form, as we have seen with the short-faced tumbler. 1872

→ We have seen that 1859 1860 1861 1866

And 1869 1872

→ of animals, 1859 1860 1861 1866

or sub-groups, 1869

or in certain sub-groups alone, 1872

→ and 1859 1860 1861

land-shells, fresh-water crustaceans, 1866 1869 1872

→ with a few 1859 1860 1861 1866

some 1869 1872

→ these cases not undergoing 1859 1860 1861 1866

these groups not passing through 1869

such groups not passing through 1872

→ or closely resembling their parents from their earliest age, 1859 1860 1861

OMIT 1866 1869 1872

→ during a course of modification carried on for many generations, 1859 1860 1861 1866

OMIT 1869 1872

→ for their own wants at a very early stage of development, and secondly, 1859 1860 1861

at a very early stage of development for their own wants, and secondly, 1866

at a very early age for their own wants, and 1869 1872

the fore-limbs →in the embryos of

these

the

several →descendants of the parent-species will still resemble each other closely, for they will not have been modified. But in each

individual

of our

new species, the embryonic fore-limbs will differ greatly from the fore-limbs in the mature animal; the limbs in the

later

latter

having undergone much modification at a rather late period of life, and having thus been converted into hands, or paddles, or wings. Whatever

influence,

influence

→long-continued exercise or use on the one hand, and disuse on the other, may have →in modifying an organ, such influence will mainly affect the mature animal, which has come to its full powers →of activity and has

had to

gain

their

its

own living; and the

effect

effects

thus produced will →be inherited at

the

corresponding

nearly mature

mature

age.

Thus

Whereas

the young will →remain unmodified, or →be modified →in a lesser degree, by the effects of use and disuse.

→In certain cases

~~the~~

the

successive →steps of variation might supervene, from causes of which we are wholly ignorant, at a very early period of life, or

the

each

steps

step

→might be inherited at an earlier

age

period

than that at which

they

first

occurred.

appeared.

In either →case (as with the short-faced tumbler) the young or embryo

will

would

closely resemble the mature →parent-form. →We have seen that this is the rule of development in certain whole

groups,

groups

→of animals, as with

cuttle-fish

cuttle-fish,

cuttle fish

→and spiders, and →with a few members of the great class of

insects.

insects,

~~with~~

with

~~Aphis.~~

Aphis.

With respect to the final cause of the young in →these cases not undergoing any metamorphosis, →or closely resembling their parents from their earliest age, we can see that this would

result

from the

~~two~~

two

following

contingencies;

contin- gencies:

contingencies:

namely,

firstly,

from the

young

young,

→during a course of modification carried on for many generations, having to provide →for their own wants at a very early stage of development, and secondly,