22 On the present state ofZooloyy. 



serve to elucidate all the laws by which the exact plan of nature is 

 regulated. 



We would here briefly remind those who enter upon the investiga- 

 tion of the natural affinities of animals, of the importance of being 

 guided by certain acknowledged principles, — quite independent of 

 those general laws above alluded to, indeed independent of all theory 

 whatever, and equally deserving our regard, whether we incline to any 

 theory or not. They respect the value of organs and the subordina- 

 tion of characters. Except we set out in our enquiries with some 

 definite ideas on these points, we shall be perpetually falling into er- 

 ror. In order to discover the true affinities of animals, it is not suf- 

 ficient that we compare their respective characters, — and then note 

 what marks of resemblance are to be traced between them : — we must 

 first ascertain what is the relative value of the different organs, which 

 furnish those characters. And how is this to be determined? — By 

 observing which organs exercise the most important functions, or are 

 of most general occurrence. It will be found on such an enquiry, 

 that some appear to take the lead of others, — that while some are 

 constantly present, others are often wanting, — and that even among 

 the former, we may trace, in different instances, very different degrees 

 of variation. Now by paying regard to these circumstances, we es- 

 tablish gradually that subordination of characters, to which we have 

 before alluded as first employed in this science by Cuvier, and which 

 must be the basis of all natural classification. Our limits will not 

 allow us to enter at any length upon this subject, or we might advert 

 to certain rules, founded — partly upon observed facts — partly upon 

 common principles of reasoning, which have been drawn up with re- 

 ference to these enquiries, and which ought to be well studied by the 

 Zoologist. * We regret, indeed, that, in some instances, they have 

 not been more attended to. Had it been otherwise, we should not 

 see so many conflicting opinions respecting classification ; — we should 

 not see groups of very unequal value placed exactly upon the same 

 footing, — genera founded upon the most trivial distinctions, and such 



* Many of these rules apply equally well, or with some slight modification 

 may be made applicable, to the two sciences of Zoology and Botany. On these 

 grounds, we strongly recommend to the attention of naturalists some portions of 

 the Theorie elementaire de la Botanique of M. Decandolle, where they are laid 

 down with more clearness and precision than in any zoological work with which 

 we are acquainted. The student, however, may consult with advantage the 

 seventh part of Lamarck's Introduction to his Hist. Nat. des. An. sans Vertebres, 

 divesting it of those peculiar theoretical views which pervade the whole of that 

 volume. 



