PRINCIPAL'SYSTEMS OF ZOOLOGY 235 



sciousness, ever since 1812; and, second, in having allowed that of 

 complication of structure frequently to take the precedence over the 

 more general features of plan, which, to be correctly appreciated, re- 

 quire, it is true, a deeper insight into the structure of the whole ani- 

 mal kingdom than is needed merely for the investigation of anatom- 

 ical 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 century, the idea of the existence of branches, char- 

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

 tions among animals, has prevailed over the idea of a gradated scale 

 including all animals in one progressive series. When it is considered 

 that this has taken place amidst the most conflicting views respecting 

 Classification 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 classifi- 

 cations 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 in- 

 vestigation; and I maintain that the first sketch of Cuvier, with all its 

 imperfections of details, presents a picture of the essential relations 

 existing among animals truer to nature than the seemingly more 

 correct classifications of recent writers. 



SECTION V 

 PHYSIOPHILOSOPHICAL SYSTEMS 



About the time that Cuvier and the French naturalists were trac- 

 ing the structure of the animal kingdom and attempting to erect a 

 natural system of Zoology upon this foundation, there arose in Ger- 

 many a school of philosophy under the lead of Schelling which ex- 

 tended its powerful influence to all the departments of physical sci- 



