age. The calf, for instance, has inherited teeth, which never
cut through the gums of the upper jaw, from an early progenitor having
well-developed teeth; and we may believe, that the teeth in the mature
animal were formerly reduced by disuse, owing to the tongue and palate,
or lips, having become excellently fitted through natural selection to
browse without their aid; whereas in the calf, the teeth have been left
unaffected, and on the principle of inheritance at corresponding ages
have been inherited from a remote period to the present day. On the view
of each organism with all its separate parts having been specially
created, how utterly inexplicable is it that organs bearing the plain
stamp of inutility, such as the teeth in the embryonic calf or the
shrivelled wings under the soldered wing covers of many beetles, should
so frequently occur. Nature may be said to have taken pains to reveal
her scheme of modification, by means of rudimentary organs, of
embryological and homologous [corresponding] structures, but we are too
blind to understand her meaning.

I have now recapitulated the facts and considerations which have
thoroughly convinced me that species have been modified, during a long
course of descent. This has been effected chiefly through the natural
selection of numerous successive, slight, favourable variations; aided
in an important manner by the inherited effects of the use and disuse of
parts; and in an unimportant manner, that is, in relation to adaptive
structures, whether past or present, by the direct action of external
conditions, and by variations which seem to us in our ignorance to arise
spontaneously. It appears that I formerly underrated the frequency and
value of these latter forms of variation, as leading to permanent
modifications of structure independently of natural selection. But as
my conclusions have lately been much misrepresented, and it has been
stated that I attribute the modification of species exclusively to
natural selection, I may be permitted to remark that in the first
edition of this work, and subsequently, I placed in a most conspicuous,
position--namely, at the close of the Introduction--the following words:
"I am convinced that natural selection has been the main but not the
exclusive means of modification." This has been of no avail. Great is
the power of steady misrepresentation; but the history of science shows
that fortunately this power does not long endure.

It can