290 ON THE CLASSES OF THE 



the little knowledge its author can possess of the lower 

 tribes of animals, that I almost fear the reader will consider 

 it as trifling with his time to discuss any position which 

 M. Geoffroy may advance on Entomology. He will be 

 the more disposed to form this conclusion, from knowing 

 the decided and cutting remark which Cuvier has made on 

 the entomological debut of his brother professor. But as no 

 less a naturalist thanM. Latreille has judged it necessary in 

 one of his most interesting papers to take notice of the 

 first " Memoir e sur I 'Organization des Insect es" I cannot 

 have the presumption to disregard it. 



When M. Geoffroy says that the external envelope of 

 the body of insects represents the internal articulated 

 column of the Vertebrata, he admits that he only expresses 

 an old opinion of an Englishman,Willis, published in 1 692 ; 

 and he has not even the credit of reviving this notion, as 

 he wilt himself perceive by studying the works of Dume- 

 ril and other Entomologists. 



It has been well stated by M. Cuvier in his Lecons 

 d'Anatomie Compared, that, whatever their consistence or 

 chemical nature may be 1 , the hard external organs of white- 

 blooded animals should, vvith respect to their mode of 

 growth, be rather compared to epidermis or horn than 

 to true bones. So that it becomes difficult to discern any 

 analogy which such external organs can have to bones, more 

 close than that which may arise from the circumstance 

 that the muscles are attached to them, as being the most 

 solid parts of the body. But granting, for the sake of ar- 

 gument, the shells of a lobster to be true bones, We thus 

 have less a principle of affinity than one of distinction, 

 which can have no more rigorous meaning than that of its 

 original propounder, " quoad membra et partes motrices 



