238 ESSAY ON CLASSIFICATION 



animal kino;dom, but also as the standard measure of the oroaniza- 

 tion of animals. There exists nothing in the animal kingdom which 

 is not represented in higher combinations in Man. The existence of 

 several distinct plans of structure among animals is virtually denied. 

 They are all built after the pattern of Man; the differences among 

 them consist only in their exhibiting either one system only, or a 

 larger or smaller number of systems of organs of higher or lower 

 physiological importance, developed either singly or in connection 

 with one another, in their body. The principles of classification of 

 both Cuvier and Ehrenberg are here entirely negatived. The prin- 

 ciple of Cuvier, who admits four different plans of structure in the 

 animal kingdom, is indeed incompatible with the idea that all ani- 

 mals represent only the organs of Man. The principle of Ehrenberg, 

 who considers all animals as equally perfect, is as completely irrecon- 

 cilable with the assumption that all animals represent an unequal 

 sum of organs; for, according to Oken, the body of animals is, as it 

 were, the analyzed body of Man, the organs of which live singly or 

 in various combinations as independent animals. Each such combina- 

 tion constitutes a distinct class. The principle upon which the orders 

 are founded has already been explained above. 



There is something very taking in the idea that Man is the stand- 

 ard of appreciation of all animal structures. But all the attempts 

 which have thus far been made to apply it to the animal kingdom 

 as it exists must be considered as complete failures. In his different 

 works Oken has successively identified the systems of organs of Man 

 with different groups of animals, and different authors, who have 

 adopted the same principle of classification, have identified them in 

 still different ways. The impracticability of such a scheme must be 

 obvious to any one who has satisfied himself practically of the exist- 

 ence of different plans of structure in the organization of animals. 

 Yet the unsoundness of the general principle of the classifications of 

 the physiophilosophers should not render us blind to all that is valu- 

 able in their special writings. The works of Oken in particular teem 

 with original suggestions respecting the natural affinities of animals; 

 and his thorough acquaintance with every investigation of his pred- 

 ecessors and contemporaries shows him to have been one of the most 

 learned zoologists of this century. 



