The
framework framework 1859 1860 1861 1866 | similar framework 1869 1872 |
of bones
being being 1859 1860 1861 1866 | in 1869 1872 |
the same in the the same in the 1859 1860 |
similar in the 1861 1866 |
the 1869 1872 |
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
leg leg 1859 1860 1861 1866 |
in the leg 1869 1872 |
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
alike in the alike in the 1859 1860 1861 1866 |
aboriginally alike in an 1869 1872 |
early progenitor
of of 1859 1860 1861 1866 | in 1869 1872 |
each
class. class. 1859 1860 1861 1866 |
of these classes. 1869 1872 |
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 can 1859 1860 1861 | can 1866 1869 1872 |
clearly see why the embryos of mammals, birds, reptiles, and fishes should be
so closely
alike, alike, 1859 1860 1861 | similar, 1866 1869 1872 |
and
should be should be 1859 1860 1861 | are 1866 | should be 1869 1872 |
so unlike the
adult forms. We may cease marvelling at the embryo of an air-breathing mammal
or bird having branchial slits and arteries running in loops, like those
in in 1859 1860 1861 1866 | of 1869 1872 |
a fish which has to breathe the
air dissolved in
water, water, 1859 1860 | water 1861 1866 1869 1872 |
by the aid of well-developed branchiæ. |
Disuse, aided sometimes by natural selection, will
often
tend to reduce an tend to reduce an 1859 1860 1861 1866 |
reduced 1869 |
have reduced 1872 |
organ, organ, 1859 1860 1861 1866 | organs 1869 1872 |
when
it has become useless by it has become useless by 1859 1860 1861 1866 |
they have become useless under 1869 |
rendered useless under 1872 |
changed habits or
under changed under changed 1859 1860 1861 1866 | under changed 1869 1872 |
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
of acting of acting 1859 1860 1861 1866 | of acting 1869 1872 |
on an organ during early life; hence the organ will not be
much much 1859 1860 1861 1866 | much 1869 1872 |
reduced or rendered rudimentary at this early age. The calf, for instance, has inherited teeth, which never cut through the gums of the upper jaw, from an early progenitor having well-developed teeth; and we may believe, that the teeth in the mature animal were
reduced, during successive generations, reduced, during successive generations, 1859 1860 1866 1869 |
reduced, during successive genera- tions, 1861 |
formerly reduced 1872 |
by
disuse disuse 1859 1860 1861 | disuse, 1866 1869 1872 |
or by or by 1859 1860 1861 1866 1869 | owing to 1872 |
the tongue and
palate palate 1859 1860 | palate, 1861 1866 1869 1872 |
having been better fitted by having been better fitted by 1860 |
having been fitted by 1859 |
or lips, having become better fitted by 1861 1866 1869 |
or lips, having become excellently fitted through 1872 |
natural selection to browse without their aid; whereas in the calf, the teeth have been left
untouched by selection or disuse, untouched by selection or disuse, 1859 1860 1861 1866 1869 |
unaffected, 1872 |
and on the principle of inheritance at corresponding ages have been inherited from a remote period to the present day. On the view of each
organic organic 1859 1860 1861 1866 1869 | organism 1872 |
being and each separate organ being and each separate organ 1859 1860 1861 |
being and each of its separate parts 1866 |
being with all its separate parts 1869 |
with all its separate parts 1872 |
having been specially created, how utterly inexplicable
it is it is 1859 1860 1861 1866 1869 | is it 1872 |
that
parts, like parts, like 1859 1860 1861 |
organs, like 1866 |
organs bearing the plain stamp of inutility, such as 1869 1872 |
the teeth in the embryonic calf or
like like 1859 1860 1861 | like 1866 1869 1872 |
the shrivelled wings under the soldered wing-covers of
some some 1859 1860 1861 1866 | many 1869 1872 |
beetles, should
thus thus 1859 1860 1861 1866 | thus 1869 1872 |
so frequently
bear the plain stamp of inutility! bear the plain stamp of inutility! 1860 1861 1866 |
bear the plain stamp of inutility! Nature may be said to have taken pains to reveal, by rudimentary organs and by homologous structures, her scheme of modification, which it seems that we wilfully will not understand. 1859 |
occur. 1869 1872 |
Nature may be said to have taken pains to
reveal, reveal, 1860 1861 1866 | reveal 1869 1872 |
by rudimentary organs and by homologous structures, by rudimentary organs and by homologous structures, 1860 1861 1866 |
OMIT 1869 1872 |
her scheme of modification,
|