EVOLUTION OF LIFE. (59 



their course : it is not the existence of the or- 

 gans which subserve to these purposes, which 

 constitutes the distinguishing characteristic be- 

 tween vegetables and animals, as Mr. HUNTER 

 imagined. However varied the organs may 

 be, which subserve to the growth and support 

 of the system in animals, from what they are in 

 vegetables, they all subserve to the same use, 

 and are regulated by the same laws : in all, 

 they are intended to build and to erect a system 

 in the best possible way, fitted and adapted to 

 perform certain determinate ends. It is be- 

 cause the ends are different in each, that there 

 exists a diversity in the means. While the 

 existence of a sensitive principle, of which a 

 nervous system is the immediate recipient, ap- 

 pears to form the distinction between animals 

 and vegetables, and not the existence of a 

 stomach, as Mr. HUNTER supposed, so the 

 magnitude of the brain with relation to the 

 organs of sense, forms the principal grounds of 

 difference between irrational and rational ani- 

 mals, between brutes and the, human species. 

 The physiologists who first directed their 

 attention to this subject, proceeded on wrong 

 data ; instead of comparing the magnitude of 

 the brain, with relation to the size of the nerves 

 which proceed from it, they compared the 

 relation which it bore to the aggregate weight 

 of the body. It is not, therefore, surprising. 



