How inexplicable are
these facts these facts 1859 1860 1861 1866 1869 |
the cases of serial homologies 1872 |
on the ordinary view of creation! Why should the brain be enclosed in a box composed of such numerous and such
extraordinarily extraordinarily 1859 1861 1872 | extraordinary 1860 | extra-ordinarily 1866 | extraor- dinarily 1869 |
shaped pieces of
bone? bone? 1859 1860 1861 1866 1869 |
bone, apparently representing vertebræ? 1872 |
As Owen has remarked, the benefit derived from the yielding of the separate pieces in the act of parturition
of of 1859 1860 1861 1866 1869 | by 1872 |
mammals, will by no means explain the same construction in the skulls of
birds. birds. 1859 1860 1861 |
birds and reptiles. 1866 1869 1872 |
Why should similar bones have been created
in the formation of in the formation of 1859 1860 1861 1866 |
to form 1869 1872 |
the wing and
leg leg 1859 1860 1861 | the leg 1866 1869 1872 |
of a bat, used as they are for such totally different
purposes? purposes? 1859 1860 1861 1866 1869 |
purposes, namely flying and walking? 1872 |
Why should one crustacean, which has an extremely complex mouth formed of many parts, consequently always have fewer legs; or conversely, those with many legs have simpler mouths? Why should the sepals, petals, stamens, and
pistils pistils 1859 1860 1861 1866 | pistils, 1869 1872 |
in
any individual any individual 1859 1860 1861 1866 | each 1869 1872 |
flower, though fitted for such
widely different widely different 1859 1860 1861 1866 1869 | distinct 1872 |
purposes, be all constructed on the same pattern? |
On the theory of natural selection, we
can can 1859 1860 1861 1866 1869 | can, 1872 |
satisfactorily satisfactorily 1859 1860 1861 1866 |
to a certain extent, 1872 |
OMIT 1869 |
answer these questions.
In the vertebrata, we see In the vertebrata, we see 1859 1860 1861 1866 1869 |
We need not here consider how the bodies of some animals first became divided into 1872 |
a series of
internal vertebræ bearing certain processes and appendages; in the articulata, we see the body internal vertebræ bearing certain processes and appendages; in the articulata, we see the body 1859 1860 1861 1866 |
internal vertebræ bearing certain processes; in the articulata, the body 1869 |
segments, or how they became 1872 |
divided into
a series of segments, bearing external appendages; and in flowering plants, we see a series of successive spiral whorls of leaves. a series of segments, bearing external appendages; and in flowering plants, we see a series of successive spiral whorls of leaves. 1859 1860 1861 1866 |
a series of segments, bearing external appendages; and in flowering plants, spiral whorls of leaves. 1869 |
right and left sides, with corresponding organs, for such questions are almost beyond investigation. 1872 |
↑2 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | It is, however, probable that some serial structures are the result of cells multiplying by division, entailing the multi- plication of the parts developed from such cells.
It must suffice for our purpose to bear in mind that an indefinite repetition of the same part or organ is the common characteristic, as Owen has remarked, of all low or little specialised forms; therefore the unknown progenitor of the Vertebrata probably possessed many vertebræ; the unknown progenitor of the Articulata, many segments; and the unknown progenitor of flowering plants, many leaves arranged in one or more spires.
|
An indefinite repetition of the same part or organ is the common
characteristic characteristic 1859 1860 1861 | characteristic, 1866 1869 |
(as (as 1859 1860 1861 | as 1866 1869 |
Owen has
observed) observed) 1859 1860 1861 | observed, 1866 1869 |
of all low or
little-modified little-modified 1859 1860 | little modified 1861 1866 1869 |
forms; therefore
we may readily believe that we may readily believe that 1859 1860 1861 1866 |
OMIT 1869 |
the unknown progenitor of the vertebrata
possessed possessed 1859 1860 1861 1866 |
no doubt possessed 1869 |
many vertebræ; the unknown progenitor of the articulata, many segments; and the unknown progenitor of flowering plants, many
spiral whorls of leaves. spiral whorls of leaves. 1859 1860 1861 1866 |
leaves arranged in one or more spires. 1869 |
We have
formerly formerly 1859 1860 1861 1866 1869 | also formerly 1872 |
seen that parts many times repeated are eminently liable to
vary vary 1859 1860 1861 1866 1869 | vary, 1872 |
in number and structure; consequently it is quite probable that natural selection, during a long-continued course of modification, should have seized on a certain number of the primordially similar elements, many times repeated, and have adapted them to the most diverse purposes. in number and structure; consequently it is quite probable that natural selection, during a long-continued course of modification, should have seized on a certain number of the primordially similar elements, many times repeated, and have adapted them to the most diverse purposes. 1859 1860 1861 1866 |
in number and structure. 1869 |
not only in number, but in form. 1872 |
|