216 ESSAY ON CLASSIFICATION 



It is therefore incredible to me how, in presence of such explicit 

 expressions, Cuvier can be represented, as he is still occasionally, as 

 favoring a division of the animal kingdom into Vertebrata and In- 

 vertebrata.^2 Cuvier, moreover, was the first to recognize practically 

 the inequality of all the divisions he adopts in his system; and this 

 constitutes further a great and important step, even though he may 

 not have found the correct measure for all his groups. For we must 

 remember that at the time he wrote naturalists were bent upon estab- 

 lishing one continual uniform series to embrace all animals, between 

 the links of which it was supposed there were no unequal intervals. 

 The watchword of their school was: Natura non facit saltum. They 

 called their system la chaine des etres. 



The views of Cuvier led him to the following arrangement of the 

 animal kingdom: — 



CLASSIFICATION OF CUVIER^^ 



First Branch. Animalia Vertebrata. 

 Cl. I. Mammalia. Orders: Bimana, Quadrumana, Carnivora, Marsupialia, Rodentia, 



Edentata, Pachydermata, Ruminantia, Cetacea. 

 Cl. 2. Birds. Ord. Accipitres, Passeres, Scansores, Gallinae, Grallae, Palmipedes. 

 Cl. 3. Reptilia. Ord. Chelonia, Sauria, Ophidia, Batrachia. 

 Cl. 4. Fishes. \st Series: Fishes proper. Ord. Acanthopterygii; — Abdominales, Sub- 



brachii, Apodes; — Lophobranchii, Plectognathi; 2d Series: Chondropterygii. 



Ord. Sturiones, Selachii, Cyclostomi.®* 



Second Branch. Animalia Mollusca. 

 Cl. 1. Cephalopoda. No subdivisions into orders or families. 

 Cl. 2. Pteropoda. No subdivisions into orders or families. 

 Cl. 3. Gasteropoda. Ord. Pulmonata, Nudibranchia, Inferobranchia, Tectibranchia, 



Heteropoda, Pectinibranchia, Tubulibranchia, Scutibranchia, Cyclobranchia. 

 Cl. 4. Acephala. Ord. Testacea, Tunicata. 

 Cl. 5. Brachiopoda. No subdivisions into orders or families. 

 Cl. 6. Cirrhopoda. No subdivisions into orders or families. 



stances, one finds that there exist four principal forms, four general plans, if one can 

 express it thus, according to which all the animals seem to have been modeled, whose 

 subsequent divisions, whatever names naturalists have bestowed upon them, are only 

 modifications slight enough, founded on the development or the addition of several 

 parts, which do not change the essence of the plan."] 



^ Ehrenberg, Die Corralenthiere . . . , p. 30. 



^ Le Regne animal (2d ed.). The classes of Crustacea, Arachnids, and Insects have 

 been elaborated by Latreille. For the successive modifications the classification of 

 Cuvier has undergone, compare his Tableau elementaire . . . (1798), his paper in 

 Annales du museum . . . XIX (1812), 73, and the first edition of the Regne animal 

 published in 1817. 



"^ Compare Regne animal (2d ed.) II, 128, 383. 



