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See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1861
1869
1872

→ are 1859 1860 1861 1866
in contradistinction to their adaptive resemblances, are 1869 1872
→ in which we have to discover the lines of descent 1859 1860 1861 1866
with the acquired grades of dif- ference, marked 1869
with the acquired grades of difference, marked 1872
→ most 1859 1860 1861 1866
terms, varieties, species, genera, families, &c.; and we have to discover the lines of descent by the most 1869 1872
→ however slight their 1859 1860 1861 1866
whatever they may be and of however slight 1869 1872
→ similar in the 1861 1866
the same in the 1859 1860
the 1869 1872
→ leg 1859 1860 1861 1866
in the leg 1869 1872
→ intelligible 1859 1860 1861 1866 1869
to a large extent, intelligible 1872
→ alike in the 1859 1860 1861 1866
aboriginally alike in an 1869 1872
→ class. 1859 1860 1861 1866
of these classes. 1869 1872
→ tend to reduce an 1859 1860 1861 1866
reduced 1869
have reduced 1872
→ it has become useless by 1859 1860 1861 1866
they have become useless under 1869
rendered useless under 1872
embryological characters are
the
often the
most valuable of all. The real affinities of all organic
beings,
beings
→are due to inheritance or community of descent. The
Natural
natural
System
system
is a genealogical arrangement, →in which we have to discover the lines of descent by the →most permanent
characters
characters,
→however slight their vital
importance.
importance
may
may
be.
be.
The
similar framework
framework
of bones
in
being
→similar in the hand of a man, wing of a bat, fin of
a
the
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,
is
likewise,
likewise
→intelligible on the view of the gradual modification of parts or organs, which were →alike in the early progenitor
in
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
are
so closely
alike,
similar,
and
should be
are
are
so unlike
the
their
adult forms. We may cease marvelling at the embryo of an air-breathing
mammals
mammal
or bird having branchial slits and arteries running in loops, like those
of
in
a fish which has to breathe
the
the
air dissolved in
water,
water
by the aid of well-developed branchiæ.
Disuse, aided sometimes by natural selection,
has
will
often →tend to reduce an
organs
organ,
when →it has become useless by changed habits or
under changed
under changed
conditions of life; and we can
clearly
clearly
understand on this view the meaning of rudimentary organs. But disuse and selection will generally act on each creature, when it has