340 ESSAY ON CLASSIFICATION. 



There is something very taking in the idea that Man is 

 the standard 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 different ways again. The impractica- 

 bility of such a scheme must be obvious to any one who 

 has satisfied himself practically of the existence of differ- 

 ent plans of structure in the organization of animals. Yet 

 the unsoundness of the general principle of the classifica- 

 tions of the physiophilosophers should not render us blind 

 to all that is valuable in their special writings. The 

 works of Oken, in particular, teem with original sugges- 

 tions respecting the natural affinities of animals ; and his 

 thorough acquaintance with every investigation of his 

 predecessors and contemporaries shows him to have been 

 one of the most learned zoologists of this century. 



CLASSIFICATION OF FITZINGER. 



This diagram is extracted from Fitzinger's Systema Reptilium ; Vindo- 

 bonze, 1843, 1 vol. 8vo. 



I. Provincia. EVERTEBRATA. 



Animalia systematum anatomicorum vegetativorum gradum evolutionis 

 exhibentia. 



A. Gradus evolutionis systematum physiologicorum vegetativorum. 

 I. Circulus. GASTROZOA. 



Evolutio systematis nutritionis. 



a. Evolutio praevalens 1. Evolutio prsevalens c. Evolutio przevalens 

 systematis digestionis. systematis circulationis. systematis rcspirationis. 



CL. 1. INFUSORIA. CL. 2. ZOOPHTTA. CL. 3. 



