78 MEANING OF ORDERS. 



Animal Kingdom into the Apathetic, Sensitive, 

 and Intelligent animals. The Apathetic were 

 those devoid of all sensitiveness except when 

 aroused by the influence of some external agent. 

 Under this head he placed five classes, includ- 

 ing the Infusoria, Polyps, Star-Fishes, Sea-Ur- 

 chins, Tunicata, and Worms, thus bringing 

 together indiscriminately Radiates, Mollusks, and 

 Articulates. Under the head of Sensitive he 

 had also a heterogeneous assemblage, including 

 Winged Insects, Spiders, Crustacea, Annelids, 

 and Barnacles, all of which are Articulates, and 

 with these he placed in two classes the MolluSks, 

 Conchifera, Gasteropoda, and Cephalopoda. Un- 

 der the head of Intelligent he brought together a 

 natural division, for he here united all the Ver- 

 tebrates. 



He succeeded in this way in making out a 

 series which seemed plausible enough, but when 

 we examine it, we find at once that it is perfectly 

 arbitrary ; for he has brought together animals 

 built on entirely different structural plans, when 

 he could find characters among them that seemed 

 to justify his favorite idea of a gradation of qual- 

 ities. Blainville attempted to establish the same 

 idea in another way. He founded his series on 

 gradations of form, placing together in one divis- 

 ion all animals that he considered vague and in- 

 definite in form, and in another all those that he 



