CHAP. XV.] CONCLUSION. 395 



little power on an organ during early life ; hence the organ will 

 not be reduced or rendered rudimentary at this early 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 in- 

 heritance 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 fre- 

 quently 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 con- 

 ditions, 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 mis- 

 represented, and it has been stated that I attribute the modifica- 

 tion 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 



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