Chap. III. rHYSIOrillLOSOPIIICAL SYSTEMS. 215 



animals and the Flesh-animals of Oken. Instead, however, of adopting, like Okcn, 

 anatomical names for his divisions, Fitzinger employs those most generally in use. 

 His subdivisions or grades of these two primary groups are based upon a repetition 

 of the same differences, within their respective limits. The Invertebrata, in which 

 the vegetative organs prevail, are contrasted with those in which the animal organs 

 prevail, and the same distinction is again draAvn among the Vertebrata. Each of 

 these embraces two circles founded upon the development of one particular system 

 of organs, etc. It cannot be expected that the systems founded upon such principles 

 should present a closer agreement with one another than those which are based 

 upon anatomical diflerences ; yet I would ask, what becomes of the principle itself, 

 if its advocates cannot even agree upon what anatomical systems of organs their 

 classes are founded ? According to Oken, the Mollusks (Acephala, Gasteropoda, and 

 Cephalopoda) represent the system of circulation, at least in the last edition of 

 his system he views them in that light, whilst Fitzinger considers them as repre- 

 senting the system of sensibility. Oken identifies the Articulata (Wonns, Crustacea, 

 and Insects) with the system of respiration, Fitzinger with that of motion, with 

 the exception of the Wonns, including Radiata, which he parallelizes with the 

 system of rejiroduction, etc. Such discrepancies must shake all confidence in 

 these systems, though they should not prevent us from noticing the happy com- 

 parisons and suggestions, to which the various attempts to classify the animal king- 

 dom in this way have led their authors. It is almost superfluous to add, that, 

 great as the disagreement is between the systems of different physiophilosophers, 

 we find quite as striking discrepancies between the difterent editions of the system 

 of the same author. 



Tlie j>i-iiicij)le of llie subdivision of tlie classes among Invertebrata is here exemplified from the Radiata, 



(Echinodermata.) J^ach series contains three orders. 



1st Series. 2d Series. 3d Series. 



Evoliitio pni'valens Evolutio pnvvalens Evolutio pra-valens 



systcmatis digestionis. systematis circulationis. systematis respirationis. 



A s t e r o i d e a . E c h i n o d c a . S c y t o d e r m a t a ( Ilolothurioids.) 



1. EiK'rinoidoa. 2. Comatulina. 1. Aprocta. 2. Echinina. 1. Synaptoidea. 2. Holothurioidea. 



3. Astcriniu 3. Spafangoidea. 3. Pentactoidea. 



In Vertebrata, each class has five series and each series three orders; so in ^lammalia, for example: — 



1st Series. 2d Series. 3d Series. 4th Series. 5th Series. 



Evolutio prffivalens Evolutio pra-valens Evolutio pra^valens Evolutio pra;valens Evolutio praivalens 



sensus tactus. sensus gustus. sensus olfaetus. sensus auditus. sensus visus. 



C e t a c e a . 1* a c li y d e r ni a t a . V, d <• ii t a t a . U n g u i c u 1 a t a . 1* r i ni a t e s . 



1. Balanodea. 1. Phocina. 1. Monotremata. 1. Glires. 1. Chiropteri. 



2. Delphinodea. 2. Obesa. 2. Lipodonta. 2. Bruta. 2. Ileniipilheci. 



3. Sirenia. 3. Ruminantia. 3. Tardigrada. 3. Ferae. 3. Anthropomorphi. 



