480 
CONCLUSION. 
Chap. XIY. 
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 genera¬ 
tions, by disuse or by the tongue and palate having been 
better 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 been modified, during a long course of descent, 
by the preservation or the natural selection of many 
successive slight favourable variations. I cannot be-,, 
lieve that a false theory would explain, as it seems to 
me that the theory of natural selection does explain, 
