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Mr. Darwin says :—
“ In order to understand the existence of rudimentary organs, we
have only to suppose that a former progenitor possessed the parts in
question in a perfect state, and that under changed habits of life
they became greatly reduced.”—{Descent of Man. 2nd ed., p. 23.)
“ Owen considers the simple filamentary limbs of the lepidosiren as
the beginnings of organs which attain full functional development in
higher vertebrates ; but, according to the view lately advocated by
Dr. Günther, they are probably remnants consisting of the persistent
axis of a fin with the lateral rays or branches aborted.”— {Origin of
Species, p. 399.)
“The wing of the penguin is of high service, acting as a fin. It may
therefore represent the nascent state of the wing. Not that I believe
this to be the case. It is more probably a reduced organ modified
for a new function.”—{Origin of Species, p. 398.)
It should be observed that the advocate of Natural
Selection does not deny that there have been, in the history
of the world, imperfect organs progressing towards per
fection ; but he asserts that the imperfect organs with
which we are actually acquainted are not progressive but
retrogressive forms. All who accept Organic Evolution
must necessarily believe in progressive development as the
demonstrated truth of science. But if this is so, it might
be asked, How does the advocate of Natural Selection come
to question the progressive character of the imperfect
organs now existing? Why does he deny that some of
these (or all of these ?) are progressive forms ? What is
the reason which perhaps unconsciously leads him to put
this spoke in the wheel of Organic Evolution ? The
answer seems to be quite a simple one. He has to prove
that Organic Evolution has taken place through the action
of Natural Selection, and he looks with suspicion upon all
processes which cannot be so explained. In doing this he
limits the action of Organic Evolution by the logical
requirement of the theory of Natural Selection, which is