The Origin of Species by Means of Natural Selection: Or, the Preservation of Favoured Races in the Struggle for Life, 6th EditionDarwin, Charles
History
The Origin of Species by Means of Natural Selection: Or, the Preservation of Favoured Races in the Struggle for Life, 6th Edition
Darwin, Charles
Evolution (Biology); Natural selection
Another distinguished zoologist, the late Professor Claparède, has
argued in the same manner, and has arrived at the same result. He shows
that there are parasitic mites (Acaridæ), belonging to distinct
sub-families and families, which are furnished with hair-claspers.
These organs must have been independently developed, as they could not
have been inherited from a common progenitor; and in the several groups
they are formed by the modification of the fore legs, of the hind legs,
of the maxillæ or lips, and of appendages on the under side of the hind
part of the body.
In the foregoing cases, we see the same end gained and the same
function performed, in beings not at all or only remotely allied, by
organs in appearance, though not in development, closely similar. On
the other hand, it is a common rule throughout nature that the same end
should be gained, even sometimes in the case of closely related beings,
by the most diversified means. How differently constructed is the
feathered wing of a bird and the membrane-covered wing of a bat; and
still more so the four wings of a butterfly, the two wings of a fly,
and the two wings with the elytra of a beetle. Bivalve shells are made
to open and shut, but on what a number of patterns is the hinge
constructed, from the long row of neatly interlocking teeth in a Nucula
to the simple ligament of a Mussel! Seeds are disseminated by their
minuteness, by their capsule being converted into a light balloon-like
envelope, by being embedded in pulp or flesh, formed of the most
diverse parts, and rendered nutritious, as well as conspicuously
coloured, so as to attract and be devoured by birds, by having hooks
and grapnels of many kinds and serrated awns, so as to adhere to the
fur of quadrupeds, and by being furnished with wings and plumes, as
different in shape as they are elegant in structure, so as to be wafted
by every breeze. I will give one other instance: for this subject of
the same end being gained by the most diversified means well deserves
attention. Some authors maintain that organic beings have been formed
in many ways for the sake of mere variety, almost like toys in a shop,
but such a view of nature is incredible. With plants having separated
sexes, and with those in which, though hermaphrodites, the pollen does
not spontaneously fall on the stigma, some aid is necessary for their
fertilisation. With several kinds this is effected by the
pollen-grains, which are light and incoherent, being blown by the wind
through mere chance on to the stigma; and this is the simplest plan
which can well be conceived. An almost equally simple, though very
different plan occurs in many plants in which a symmetrical flower
secretes a few drops of nectar, and is consequently visited by insects;
and these carry the pollen from the anthers to the stigma.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account