CLASSIFICATION. 5 



2nd. Those that have not back -bones. 



Those animals that have back-bones are called 



Vertebrate, 



Those that are without back-bones are called 



Invertebrate. 



The Vertebrate division includes 



Fishes, Reptiles, Birds, and Mammals, 



The Invertebrate division is much more numerous, 

 and comprehends animals of very various construc- 

 tion ; these are 



1st. Mollusks, or soft-bodied animals, such as cuttle- 

 fishes, snails, oysters, &c. ; 



2nd. Articulated Animals, or animals enclosed in a 

 jointed skin, such as insects, spiders, and lobsters; 



3rd. Radiated Animals, under which head are in- 

 cluded all the lowest, and least perfect members of 

 the animal kingdom, many of them having few 

 characteristics in common. 



The completeness of the above classification, so far 

 as it relates to the more perfect animals, is generally 

 admitted, and we shall, therefore, take it as our 

 guide ; but among the lower tribes of creation such 

 guidance fails us, and through this labyrinth we shall 

 have to make our way by the aid of more recent in- 

 vestigations. 



In the preceding paragraph, as the reader may have 

 remarked, we have spoken of " the more perfect ani- 

 mals" as contradistinguished from those of "the 

 lower tribes," and as we shall again and again be 

 obliged to have recourse to similar expressions, the 

 terms require some explanation. Every animal is 

 perfect in its kind, and to add to, or to take from, its 

 attributes would deteriorate its usefulness in creation. 

 By the perfect or imperfect structure of an animal we 

 simply mean the degree in which it approximates to 

 Man, the type and pattern of zoological perfection, 

 just as in estimating the value of money, we take 

 the highest coin of the realm as a standard of com- 

 parison. Man, the paragon of animals, is the union 

 of what is most perfect and beautiful in them all. 



