192 ESSAY ON CLASSIFICATION. Part I. 



influence which his anatomical investigations had upon Zoology, and how the 

 improvements in classification have contributed to advance comparative anatomy, 

 when he says, in the preface to the " Regne Animal," page vi. : " Je dus done, et 

 cette obligation me prit un temps considerable, je dus faire marcher de front 

 I'anatomie et la zoologie, les dissections et le classement; chercher dans mes pre- 

 mieres remarques sur I'organisation, des distributions meilleures; m'en servir pour 

 arriver a des remarques nouvelles; employer encore ces remarques a perfectionner 

 les distributions ; faire sortir enfin de cette fecondation mutuelle des deux sciences 

 I'une par I'autre, un systeme zoologique propi'e a servir d ' introducteur et de guide 

 dans le champ de I'anatomie, et un corps de doctrine anatomique propre h servir 

 de developpement et d'explication au systeme zoologique." 



Without entex-ing 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 characterized in this manner. These classes are : the MoUusks, 

 Cirripeds, Crustacea, Ai'aclmids, Annelids, Entozoa, (Intestinal Worms,) Zoophytes, 

 Radiata, Polyps, and Infusoria. Cuvier^ admitted at first only eight classes, DumeriP 

 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, constitute 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 Linnaeus 

 have undergone under the influence of Cuvier, I have not, of course, alluded to 

 the important contributions made to our knowledge of isolated classes, by special 

 writers, but limited my remarks to the works of those naturalists Avho have con- 

 sidered 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 C"« traifuc and ^coa draifin. All efforts 

 were rather directed towards establishing a natural series, from the lowest Infusoria 

 up to Man ; which, with many, soon became a favorite tendency, and ended by 

 being presented as a scientific doctrine by Blainville. 



' Cuvier, (G.,) Tableau elementaire de I'Histoire ' Lamarck, (J. B. de,) Systeme des Aniniaux 



naturelle des Animaux, Paris, 1798, 1 vol. 8vo. sans Vertebras ou Tableau general, etc., Paris, 1801, 



^ DuMERiL, (A. M. C.,) Zoologie analytique, etc., 1 vol. 8vo. — Ilistoire naturelle des Animaux sans 



Paris, 180G, 1 vol. 8vo. Vertebres, etc.. Paris, 1815-1822, 7 vols. 8vo. 



