Comparison with 1872 |
|
by the most
permanent characters,
however slight their
vital importance
may be. |
|
The framework
of bones being
the same in the
hand of a man, wing of a bat, fin of
a a 1872 | the 1859 1860 1861 1866 1869 |
porpoise, and leg of the horse,— the same number of vertebræ forming the neck of the giraffe and of the elephant,— and innumerable other such facts, at once explain themselves on the theory of descent with slow and slight successive modifications. The similarity of pattern in the wing and leg
of a bat, though used for such different purpose,— in the jaws and legs of a crab,— in the petals, stamens, and pistils of a
flower flower 1872 | flower, 1859 1860 1861 1866 1869 |
is
likewise, likewise, 1872 | likewise 1859 1860 1861 1866 1869 |
to a large extent, intelligible to a large extent, intelligible 1872 |
intelligible 1859 1860 1861 1866 1869 |
on the view of the gradual modification of parts or organs, which were alike in the
early progenitor of
each class. On the principle of successive variations not always supervening at an early age, and being inherited at a corresponding not early period of life, we can
clearly see why the embryos of mammals, birds, reptiles, and fishes
should be should be 1859 1860 1861 1872 | are 1866 1869 |
so closely alike,
and should be
so unlike the
adult forms. We may cease marvelling at the embryo of an air-breathing
mammal mammal 1859 1860 1861 1866 1872 | mammals 1869 |
or bird having branchial slits and arteries running in loops, like those in
a fish which has to breathe
the the 1859 1860 1861 1866 1872 | the 1869 |
air dissolved in water,
by the aid of well-developed branchiæ. |
|
Disuse, aided sometimes by natural selection,
will will 1859 1860 1861 1866 1872 | has 1869 |
often
have reduced have reduced 1872 |
tend to reduce an 1859 1860 1861 1866 |
reduced 1869 |
organ,
when
rendered useless under rendered useless under 1872 |
it has become useless by 1859 1860 1861 1866 |
they have become useless under 1869 |
changed habits or under changed
conditions of life; and we can
....... 1872 | clearly 1859 1860 1861 1866 1869 |
understand on this view the meaning of rudimentary organs. But disuse and selection will generally act on each creature, when it has come to maturity and has to play its full part in the struggle for existence, and will thus have little power of acting
on an organ during early life; hence the organ will
|
by the
terms, varieties, species, genera, families, &c.; and we have to discover the lines of descent by the most terms, varieties, species, genera, families, &c.; and we have to discover the lines of descent by the most 1869 1872 |
most 1859 1860 1861 1866 |
permanent
characters characters 1869 1872 | characters, 1859 1860 1861 1866 |
whatever they may be and of however slight whatever they may be and of however slight 1869 1872 |
however slight their 1859 1860 1861 1866 |
vital
importance. importance. 1869 1872 | importance 1859 1860 1861 1866 |
....... 1869 1872 | may 1859 1860 1861 1866 |
....... 1869 1872 | be. 1859 1860 1861 1866 |
|
|
The
similar framework similar framework 1869 1872 | framework 1859 1860 1861 1866 |
of bones
in in 1869 1872 | being 1859 1860 1861 1866 |
the the 1869 1872 |
the same in the 1859 1860 |
similar in the 1861 1866 |
hand of a man, wing of a bat, fin of
the the 1859 1860 1861 1866 1869 | a 1872 |
porpoise, and leg of the horse,— the same number of vertebræ forming the neck of the giraffe and of the elephant,— and innumerable other such facts, at once explain themselves on the theory of descent with slow and slight successive modifications. The similarity of pattern in the wing and
in the leg in the leg 1869 1872 |
leg 1859 1860 1861 1866 |
of a bat, though used for such different purpose,— in the jaws and legs of a crab,— in the petals, stamens, and pistils of a
flower, flower, 1859 1860 1861 1866 1869 | flower 1872 |
is
likewise likewise 1859 1860 1861 1866 1869 | likewise, 1872 |
intelligible intelligible 1859 1860 1861 1866 1869 |
to a large extent, intelligible 1872 |
on the view of the gradual modification of parts or organs, which were
aboriginally alike in an aboriginally alike in an 1869 1872 |
alike in the 1859 1860 1861 1866 |
early progenitor
in in 1869 1872 | of 1859 1860 1861 1866 |
each
of these classes. of these classes. 1869 1872 |
class. 1859 1860 1861 1866 |
On the principle of successive variations not always supervening at an early age, and being inherited at a corresponding not early period of life, we
....... 1866 1869 1872 | can 1859 1860 1861 |
clearly see why the embryos of mammals, birds, reptiles, and fishes
are are 1866 1869 | should be 1859 1860 1861 1872 |
so closely
similar, similar, 1866 1869 1872 | alike, 1859 1860 1861 |
and
....... 1869 1872 | should be 1859 1860 1861 | are 1866 |
so unlike
the the 1859 1860 1861 1869 1872 | their 1866 |
adult forms. We may cease marvelling at the embryo of an air-breathing
mammals mammals 1869 | mammal 1859 1860 1861 1866 1872 |
or bird having branchial slits and arteries running in loops, like those
of of 1869 1872 | in 1859 1860 1861 1866 |
a fish which has to breathe
....... 1869 | the 1859 1860 1861 1866 1872 |
air dissolved in
water water 1861 1866 1869 1872 | water, 1859 1860 |
by the aid of well-developed branchiæ. |
|
Disuse, aided sometimes by natural selection,
has has 1869 | will 1859 1860 1861 1866 1872 |
often
reduced reduced 1869 |
tend to reduce an 1859 1860 1861 1866 |
have reduced 1872 |
organs organs 1869 1872 | organ, 1859 1860 1861 1866 |
when
they have become useless under they have become useless under 1869 |
it has become useless by 1859 1860 1861 1866 |
rendered useless under 1872 |
changed habits or
....... 1869 1872 | under changed 1859 1860 1861 1866 |
conditions of life; and we can
clearly clearly 1859 1860 1861 1866 1869 | clearly 1872 |
understand on this view the meaning of rudimentary organs. But disuse and selection will generally act on each creature, when it has come to maturity and has to play its full part in the struggle for existence, and will thus have little power
....... 1869 1872 | of acting 1859 1860 1861 1866 |
on an organ during early life; hence the organ will
|