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 
were sure to be rejected on further investiga- 
tion. Some of these criticisms and additions, 
however, were truly improvements, and touched 
upon points overlooked by Cuvier. Blainville, 
especially, took up the element of form among 
animals, — whether divided on two sides, wheth- 
er radiated, whether irregular, etc. He, 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 Actinozoaria, 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 
2 
