ANATOMICAL SYSTEMS. 335 



which have been proposed since Cuvier consists, firstly, in 

 having given up, to a greater or less extent, the funda- 

 mental idea of the plan of structure, so beautifully brought 

 forward by Cuvier, and upon which he has insisted with 

 increased confidence, and more and more distinct consci- 

 ousness, ever since 1812; and, secondly, in having fre- 

 quently allowed that of complication of structure to take 

 the precedence over the more general features of plan, to. 

 correctly appreciate which recjuires, it is true, a deeper 

 insight into the structure of the whole animal kingdom 



O ' O 



than is needed merely for the investigation of anatomical 

 characters in single types. 



Yet, if we take a retrospective glance at these systems, 

 and especially consider the most recent ones, it must be 

 apparent to those who are conversant with the views now 

 obtaining in our science, that, after a test of half a cen- 

 tury, the idea of the existence of branches characterized 

 by different plans of structure, as expressing the true rela- 

 tions among animals, has prevailed over the idea of a 

 graduated scale including all animals in one progressive 

 series. When it is considered that this has taken place 

 amidst the most conflicting views respecting Classifica- 

 tion, and even in the absence of any ruling principle, it 

 must be acknowledged that this can be only owing to the 

 internal truth of the views first propounded by Cuvier. 

 We recognize in the classifications of Siebold, Leuckart, 

 and others, the triumph of the great conception of the 

 French naturalist, even though their systems differ greatly 

 from his ; for the question, whether there are four or more 

 great plans, limited in this or any other way, is not a 

 question of principle, but one involving only accuracy and 

 penetration in the investigation ; and I maintain that the 

 first sketch of Cuvier, with all its imperfections of details, 



