Again, an organ, useful under certain conditions, might
become injurious under others, as _with the wings of beetles living
on small and exposed islands_; and in this case natural selection
will have aided in reducing the organ, until it was rendered
harmless and rudimentary [italics mine]." {266}
So that just as an undefined amount of use and disuse was introduced
on the earlier page to supplement the effects of natural selection
in respect of the wings of beetles on small and exposed islands, we
have here an undefined amount of natural selection introduced to
supplement the effects of use and disuse in respect of the identical
phenomena. In the one passage we find that natural selection has
been the main agent in reducing the wings, though use and disuse
have had an appreciable share in the result; in the other, it is use
and disuse that have been the main agents, though an appreciable
share in the result must be ascribed to natural selection.
Besides, who has seen the uncles and aunts going away with the
uniformity that is necessary for Mr.
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