AND CLASSIFICATION. 25 



The publication of Cuvier's proposition, that 

 the animal kingdom is built on four plans, how- 

 ever imperfectly understood and appreciated at 

 first, created, nevertheless, an extraordinary ex- 

 citement throughout the scientific world. All 

 naturalists proceeded to test it, and some among 

 them soon recognized in it a great scientific 

 truth, — while others, who thought more of 

 making themselves prominent than of advan- 

 cing science, proposed poor amendments, that 

 wore sure to be rejected on further investiga 

 tion. Some of these criticisms and additions, 

 however, were truly improvements, and touched 

 upon points overlooked by Cnvier. Blaiiiville,*^ 

 especially, took np the element of form among 

 animals, — whether divided on two sides, wheth- 

 er radiated, whether irregular, etc. IJe, how- 

 ever, made the mistake of giving very elaborate 

 names to animals already known under simpler 

 ones. Why, for instance, call all animals with 

 parts radiating in every direction Actinomorpha 

 or Aclinozuaria, when they had received the 

 significant name of Radiates? It seemed to 

 be a new system, when in fact it was only a new 

 name. Ehrenberg, likewise, made an important 

 distinction, when he united the animals accord- 

 ing to the difference in their nervous systems ; 

 but he also encumbered the nomenclature un- 

 necessarily, when he added to the names Anaima 



