MANUAL OF NATURAL HISTORY. 7 



appears in the human race in its most perfect con- 

 dition. In the size, number, and complicated nature 

 of most of their viscera the Vertebrates shew a 

 great advance over the inferior classes ; but on these 

 points it would be out of place here to enlarge ; 

 suffice it to say, that the body is generally divisible 

 into a head, a trunk, and extremities, the latter 

 never exceeding four in number. The voluntary 

 movements attain perfection, being less automatic 

 and more the result of volition than among the 

 lower orders; and the system of organic life, so 

 developed in the mollusks, here gives way to the 

 more important system of animal life. In short, 

 taking a mollusk or a star-fish as examples of an In- 

 vertebrate, we find them to live within themselves 

 and for themselves, not exactly worshipping their 

 bellies, as they can hardly be said to possess one, yet 

 devoted to gastronomy, in which they are probably 

 adepts, and spending their time in alternate feeding 

 and repose. While in Vertebrates higher occupations 

 manifest themselves, sight, hearing, smell, taste, and 

 touch become more refined, social feelings, of a dif- 

 ferent description from those of the ants and bees, 

 are observed, passions of various kinds disturb the 

 frame, until finally the whole are centred in talking, 

 reasoning, busy, marrying man. 



1. SUB-KINGDOM OF VERTEBRATES. Vertebrata. 



Skeleton internal, jointed, vital, cartilaginous, or 

 osseous. Head distinct, enclosing, and covering 

 with the vertebrae the principal nervous centres. 



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