214 ESSAY ON CLASSIFICATION 



Without entering into a detailed account of all that was done in 

 this period towards improving the system of Zoology, it may suffice 

 to say that before the first decade of this century had passed, more 

 than twice as many classes as Linnaeus adopted had been charac- 

 terized in this manner. These classes are: the Mollusks, Cirripeds, 

 Crustacea, Arachnids, Annelids, Entozoa (Intestinal Worms), Zoo- 

 phytes, Radiata, Polyps and Infusoria. Cuvier^"^ admitted at first only 

 eight classes, Dumerips nine, Lamarck^^ eleven and afterwards 

 fourteen. The Cephalopoda, Gasteropoda, and Acephala, first so 

 named by Cuvier, are in the beginning considered by him as orders 

 only in the class of Mollusks; the Echinoderms also, though for the 

 first time circumscribed by him within their natural limits, con- 

 stitute only an order of the class of Zoophytes, not to speak of the 

 lowest animals, which, from want of knowledge of their internal 

 structure, still remain in great confusion. In this rapid sketch of the 

 farther subdivisions which the classes Insecta and Worms of Lin- 

 nseus have undergone under the influence of Cuvier, I have not, of 

 course, alluded to the important contributions made to our knowl- 

 edge of isolated classes by special writers, but limited my remarks 

 to the works of those naturalists who have considered the subject 

 upon the most extensive scale. 



Thus far no attempt had been made to combine the classes among 

 themselves into more comprehensive divisions, under a higher point 

 of view, beyond that of dividing the whole animal kingdom into 

 Vertebrata and Invertebrata, a division which corresponds to that of 

 Aristotle, into ^cba evaiixa and fcoa avaiiia. All efforts were rather 

 directed towards establishing a natural series, from the lowest Infu- 

 soria up to Man; which with many soon became a favorite tendency 

 and ended by being presented as a scientific doctrine by Blainville. 



the other, a zoological system appropriate as an introduction and guide in the field 

 of anatomy, and a body of anatomical doctrine appropriate for the development and 

 explication of the zoological system."] 



^ Tableau eUmentaire de I'histoire naturelle des animaux (Paris, 1798). 



"^ Zoologie analytique . . . (Paris, 1806). 



^ Systeme des animaux sans vertebres ou tableau general . . . (Paris, 1801), and 

 Histoire naturelle des animaux sans vertebres ... (7 vols., Paris, 1815-1822). 



