ted 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 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 hardly be supposed that a false theory would explain, in so
satisfactory a manner as does the theory of natural selection, the
several large classes of facts above specified. It has recently been
objected that this is an unsafe method of arguing; but it is a method
used in judging of the common events of life, and has often been