480 CONCLUSION. Chap. XIV. 



of life ; and we can clearly understand on this view the 

 meaning of rudimentary organs. But disuse and selec- 

 tion will generally act on each creature, when it has 

 come to maturity and has to play its full part in the 

 struggle for existence, and will thus have little power 

 of acting on an organ during early life ; hence the organ 

 will not be much 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 reduced, during successive gene- 

 rations, by disuse or by the tongue and palate having 

 been fitted by natural selection to browse without their 

 aid ; whereas in the calf, the teeth have been left un- 

 touched by selection or disuse, 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 organic being and each separate organ having 

 been specially created, how utterly inexplicable it is that 

 parts, like the teeth in the embryonic calf or like the 

 shrivelled wings under the soldered wing-covers of some 

 beetles, should thus so frequently bear the plain stamp 

 of inutility ! Nature may be said to have taken pains 

 to reveal, by rudimentary organs and by homologous 

 structures, her scheme of modification, which it seems 

 that we wilfully will not understand. 



I have now recapitulated the chief facts and consider- 

 ations which have thoroughly convinced me that species 

 have changed, and are still slowly changing by the pre- 

 servation and accumulation of successive slight favour- 

 able variations. Why, it may be asked, have all the 

 most eminent living naturalists and geologists rejected 

 this view of the mutability of species? It cannot be 



