2 CLASSIFICATION OF FISHES. 



harmony and consistency of that system upon which 

 the variation of animal structui-e has been regulated. 

 The vast assemblage of fishes comprised under this 

 order are considered by all authors, and justly^ as the 

 most perfect, or pre-eminently typical, of the whole 

 class ; that is to say, they are the most highly organised 

 of all fishes, just as the Insessores, or the perchers, are 

 among birds. Every naturalist is aware that typical 

 groups are always large, and that aberrant ones are 

 smaU : the one shows us the rule, the other the ex- 

 ceptions : the former may be compared to the broad 

 surface of a wide extending region, where all its pecu- 

 liarities of climate, scenery, and productions are seen in 

 their full development ; the latter are analogous to the 

 borders of this region, where some of the characteristics 

 of the interior districts are but faintly, and others not at 

 aU, discerned : they become, in shorty commingled with 

 those of the neighbouring provinces ; and although 

 these districts still retain sufficient of their national 

 characteristics to show to which region they truly belong_, 

 their limits are yet confined, and their general features 

 but faintly represent the typical pecuharities of the 

 region to which they naturally pertain. Every one of 

 our readers is aware of the truth of this in regard to 

 physical geography ; and the philosophic naturalist 

 knows that it is equally so in natural groups of animals. 

 It may safely be pronounced a law of nature, that what- 

 soever is most perfect in its Idnd^ or in other words 

 typical, should be most numerous, and that the de- 

 viations from this perfection should be few : these 

 deviations, in fact, are but stepping-stones or porticos 

 connecting a series of long galleries or lofty halls — 

 they are the graduated links in the chain of Nature, by 

 which all her productions, nay, aU her operations, ac- 

 quire that uniformity and harmony everywhere dis- 

 cernible. Applying all this to the case before us, we 

 need feel no surprise at the superiority, in every respect, 

 of the order of spine-rayed fishes, over all others. 



Da 



