220 ESSAY ON CLASSIFICATION 



The Sensitive animals are distinguished from the third type, the 

 Intelligent animals, by the character of their sensations. It is stated, 

 in respect to the Sensitive animals, that they obtain from their sensa- 

 tions only perceptions of objects, a sort of simple ideas which they 

 are unable to combine so as to derive from them complex ones, while 

 the Intelligent animals are said to obtain ideas which they may pre- 

 serve, and to perform with them operations by which they arrive at 

 new ideas. They are said to be Intelligent. Even now, fifty years after 

 Lamarck made those assertions, I doubt whether it is possible to dis- 

 tinguish in that way between the sensations of the Fishes, for instance, 

 and those of the Cephalopods. It is true the structure of the animals 

 called Sensitive and Intelligent by Lamarck differs greatly, but a 

 large number of his Sensitive animals are constructed upon the same 

 plan as many of those he includes among the Apathetic. They em- 

 brace, moreover, two different plans of structure, and animal psy- 

 chology is certainly not so far advanced as to afford the least founda- 

 tion for the distinctions here introduced. 



Even from his own point of view, his arrangement of the classes is 

 less perfect than he might have made it, as the Annelids stand nearer 

 to the Worms than the Insects and are very inferior to them. Having 

 failed to perceive the value of the idea of plan, and having substituted 

 for it that of a more or less complicated structure, Lamarck unites 

 among his Apathetic animals, Radiates (the Polypi and Radiaria) 

 with Mollusks (the Tunicata) and with Articulates (the Worms). 

 Among the Sensitive animals he unites Articulates (the Insects, Arach- 

 nids, Crustacea, Annelids, and Cirripeds) with Mollusks the Con- 

 chifera, and the Mollusks proper). Among the Intelligent animals 

 he includes the ancient four classes of Vertebrates, the Fishes, Rep- 

 tiles, Birds, and Mammalia. 



CLASSIFICATION OF DE BLAINVILLE^* 



1. Sub-Kingdom. Artiomorpha or Artiozoaria. Form bilateral. 

 First Type: Osteozoaria. (Vertebrata.) 

 Sub-Type: Vivipara. 



Cl. 1. Pilifera, or Mammifera. 1st. Monadelphya. 2d. Didelphya. 

 Sub-Type: Ovipara. 

 Cl. 2. Pennifera, or Aves. 

 Cl. 3. Squamifera, or Reptilia. 

 Cl. 4. Nudipellifera, or Amphibia. 



^ De I' organisation des animaiix (1822). 



