408 HISTORY OF ZOOLOGY. 



beings, a system of marks either arbitrary, or con- 

 formable to natural affinities in a partial degree. 

 And we have not often the advantage of having the 

 reasons for a systematic arrangement so clearly and 

 fully indicated, as is done here, and in the descrip- 

 tions of the separate orders. 



This arrangement Cuvier adhered to in all its 

 main points, both in the second edition of the 

 Regne Animal, published in 1821, and in his His- 

 tvire Naturelle des Poissons, of which the first 

 volume was published in 1828, but which unfor- 

 tunately was not completed at the time of his death. 

 It may be supposed, therefore, to be in accordance 

 with those views of zoological philosophy, which it 

 was the business of his life to form and to apply ; 

 and in a work like the present, where, upon so 

 large a question of natural history, we must be 

 directed in a great measure by the analogy of the 

 history of science, and by the judgments which 

 seem most to have the character of wisdom, we 

 appear to be justified in taking Cuvier' s ichthyolo- 

 gical system as the nearest approach which has yet 

 been made to a natural method in that department. 



The true natural method is only one : artificial 

 methods, and even good ones, there may be many, 

 as we have seen in botany ; and each of these may 

 have its advantages for some particular use. On 

 some methods of this kind, on which naturalists 

 themselves have hardly yet had time to form a 

 stable and distinct opinion, it is not our office to 



