ANIMAL KINGDOM. 291 



non ossa teguntur candbus, sed carries ossibus." For if we 

 once go the same length with M. GeofFroy, and attempt 

 to prove that the details of this external skeleton are ana- 

 logous to the details of the internal one of the VertebratOy 

 we must adopt for truths the wildest visions of fancy, and 

 believe in such startling vagaries as the two following. 



" The first thoracic segment of an insect, which carries 

 the two anterior feet, forms the third vertebra of the head, 

 and represents the lower jaw of fishes." 



" The elytra of Coleopterous insects correspond with 

 the opercula of Fishes, and the wings with the pulnrio- 

 nary sacs of Reptiles." 



In his second Memoire, M. GeofFroy, in attempting 

 rather ingeniously to forsake the bolder parts of his theory, 

 and to slide imperceptibly into the opinions of his oppo.> 

 nent M. Latreille, has unfortunately fallen into another 

 error. He supposes gratuitously that the Crustacea are 

 divided into two branches, one of which conducts to the 

 true Insects by means of the Scolopendra, — an affinity 

 which no one will deny, — and that the other leads to the 

 Mollusca by means of the genus Cancer! For this last 

 affinity I cannot divine any one satisfactory reason, unless 

 it be that Aristotle first imagined it, and that the vulgar 

 have constantly adopted the same opinion up to the pre- 

 Bent day. Nevertheless M. Geoffioy thinks it unneces- 

 sary to advance any proof of their connexion, which we 

 are to adopt on his word, merely modified by the obser- 

 vation that " il conviendra ajouter qii'un hiatus asse:^ 

 marque tient les MoUusques a distance." 



We now turn to M. Latreille, Ivho in his Passage des 

 Animaux Inverttbrts aux Verttbres has taken the oppo- 

 site side of the question, and has there assembled together 



U 2 



