150 FOCRTH RKI'ORT 1834, 



Before the date of this memoir, naturaUsts had generally a- 

 dopted Lamarck's primary division of Vertebrate and Inverte- 

 brate animals. Cuvier objected to this, on the ground that there 

 were as great differences of structure amongst these last, as any 

 of those by which they were separated from the vertebrate divi- 

 sion. In his Hist. Nat. des An. sans Verthb. (the first volume of 

 which was published in 1815), Lamarck somewhat modified his 

 former views, by distributing animals under the three divisions 

 of Intelligent, Sensible, and Apathetic. As this arrangement, 

 however, is obviously objectionable, and has not met with much 

 reception, I do not consider it necessary to dwell further on it*. 

 I shall proceed, therefore, to notice some modifications of Cuvier 's 

 system which have been proposed by different authors, as well 

 as some new systems and principles of arrangement which 

 have appeared since the publication of the R^gne A>iimal, and 

 which from their impoi'tance appear deserving of consideration. 



The first in order of time, with which I am acquainted, is a 

 modification of Cuvier's primary divisions proposed by Geoffroy 

 in 1820, and which arose from his peculiar views respecting the 

 unity of composition in animals. It is not necessary at the pre- 

 sent day to enter into any detailed analysis of these views, which 

 have been so long associated with the name of this distinguished 

 naturalist, and which belong more to the department of compa- 

 rative anatomy than zoology. It is sufficient to state that Geof- 

 froy, who had previously endeavoured to show that all vertebrate 

 animals were constructed so exactly upon the same plan as to 

 preserve the strictest analogy of parts in respect to their osteo- 

 logy f, thought to extend this unity of plan by demonstrating, 

 as it appeared to him, that the hard parts of Crustacea and In- 

 sects were still only modifications of the skeleton of higher ani- 

 mals, and that therefore the type of Veriebrata must be made to 

 include them also. It is impossible in this Report to follow up 

 the train of reasoning and anatomical research which guided 

 Geoffroy in his attempt to establish this theory. The general 

 results at which he arrives are, that the segments of the Annu- 

 losa are strictly analogous to the vertebrae of the higher animals, 



* Although Lamarck's leading divisions are ohjectionahle, there is much in 

 his system which is extremely valuable, particularly as i-espects the arrangement 

 of the Invertehrata. He was the first to point out that these last, if placed ac- 

 cording to their true affinities, must be considered as forming two distinct sub- 

 ramose series, one consisting of the articulated, and the other of the inarticu- 

 lated invertebrate animals. — See the Supplement to his first volume, p. 4o7. 



■\ Geoflfroy's principal memoirs relating to this subject were collected into one 

 volume, and published in 1818 under the title oi Philosophie Anatomiqiie. Se- 

 veral others however, more or less connected with it, are to be found in the Ann. 

 du Mus. 



