1 



') 



i 

 1 

 i 



e 





1 

 1 



t 





) 



) 



^ 



Ch. XXXIY.] 



CAUSED BY DOMESTICATION. 



251 



characters of the species, and, like tliem, pass by insensible 

 hades into each other, there being every intermediate gra- 

 dation between the opposite extremes. But each locality 

 remains for a very long time the same, and is altered so 

 slowly that we can only become conscious of the reality of 

 the change by consulting geological monuments, by which 

 we learn that the order of things which now reigns in each 

 place has not always prevailed, and by inference anticipate 



same 



circumstances 



which each race of animals exists causes a change in their 



them 



habits. These actions require the more frequent employment 

 of some parts before but slightly exercised, and then greater 



more 



use. 



im 



diminished in size, nay, are sometimes entirely annihilated, 

 while in their place new parts are insensibly produced for the 

 discharge of new functions. f 



I must here interrupt the author's argument, by observing. 



exem 



some 



room 



some other suppressed as useless. All the instances adduced 



mem 



bers and the perfection of certain attributes may, in a long 

 succession of generations, be lessened and enfeebled by dis- 



use: or, on the 



matured 



active exertion ; just as we know that the power of scent is 

 feeble in the greyhound, while its swiftness of pace and its 

 acuteness of sight are remarkable— that the harrier and 



com 



smelling. 



chasm m the chain of evidence, because he might otherwise 

 imagme that I had merely omitted the illustrations for the 

 sake of brevity ; but the plain truth is, that there were no 



examples to be 



lamar 



of the 



* Phil. Zool. torn. i. p. 232. 

 t Ibid. p. 234. 



X 



/ 



