See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1861
1869
1872

in the parent-species, may have become, by 1860 1861 1866
in the parent-species, may become, by 1859
to a remote progenitor, may have become, through 1869 1872

principles— namely of each successive modification supervening at a rather late age, and being inherited at a corresponding late age— 1859 1861 1866
principles— namely of each successive modification supervening at a rather late age, and being inherited at a corre- sponding late age— 1860
principles 1869 1872

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 disuse 1866
long-continued exercise or use on the one hand, and disuse on the other, 1859 1860 1861
moreover, long-continued use or disuse 1869
long-continued use or disuse 1872

had in modifying an organ, such influence will mainly affect the mature animal, which has come to its 1866
in modifying an organ, such influence will mainly affect the mature animal, which has come to its 1859 1860 1861
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

land-shells, fresh-water crustaceans, 1866 1869 1872
and 1859 1860 1861

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

OMIT 1866 1869 1872
or closely resembling their parents from their earliest age, 1859 1860 1861

which
once served
served
as legs in the parent-species, may have become, by a long course of modification, adapted in one descendant to act as hands, in another as paddles, in another as wings;
but
and
on the above two principles— namely of each successive modification supervening at a rather late age, and being inherited at a corresponding late age— 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
latter
later
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 disuse may have had in modifying an organ, such influence will mainly affect the mature animal, which has come to its full powers of activity and has
to
had to
gain
their
its
own living; and the
effect
effects
thus produced will be inherited at
a
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
it
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,
land-shells, fresh-water crustaceans, spiders, and with a few members of the great class of
insects,
insects.
as
....
with
....
Aphis.
....
With respect to the final cause of the young in these cases not undergoing any metamorphosis, OMIT we can see