THE QUINARY SYSTEM. 



xlvii 



arranged all animals into vertebrated, or those having an internal 

 articulated spine ; and invertebrated, or those having external arti- 

 culations ; * but M. Geoffroy St. Hilaire has carried the same ana- 

 logies into such minute detail, that they become not a little 

 ludicrous. He finds, for example, not only that the mem- 

 braneous lungs of birds are analogous to the swim-bladders of 

 fishes, but also to the posterior wings of insects. He tries farther 

 to make out an analogy between the various pieces of the crust- 

 aceous shell of crabs and lobsters, and the joints of the spine (ver- 

 tebra) of quadrupeds. From the spine he proceeds to the ribs, 

 which it is natural, in such a system, to expect will make their way, 

 like the vertebrae, to the outside of the body ; and accordingly 

 he states, that what we ignorantly suppose to be the legs of crabs 

 and lobsters, are, in fact, the ribs, which, by some inexplicable 

 process or transition, have pushed themselves out to the exterior, 

 and have assumed the office of legs ; while what ought to have 

 been the legs have become jaws,f and are actually called feet- 

 jaws (Pieds-mdchoires, Cuvier; Pattes-mdchoires, Savigny.) 

 Kirby and Spence, adopting this view, argue, that because one pair 

 of the eight legs in spiders, &c. (Arachnida) originate in the head, 

 and not in the trunk, though they perform the office of legs, they 

 are not, therefore, entitled to be called legs "in a primary 

 sense ;" but apparently represent the feelers or the lips of insects.^ 

 Pursuing a similar fancy, M. Savigny, with great ingenuity 

 and skill, it must be allowed, endeavoured to show that the 

 suckers of butterflies and the tongues of bees correspond with the 

 jaws of beetles and crickets. § He has reasoned so plausibly, 

 indeed, that most naturalists are led to think him right, even in 

 opposition to the obvious fact of the jaws being separate and 

 moveable, while the suckers are united, and their parts immove- 

 able. I have already remarked, that the argument would be 

 equally plausible if it were reversed ! 



These views require only to be stated, in order, I conceive, to 

 demonstrate their fanciful foundation to every unbiassed mind; 

 and Baron Cuvier has shown good sense in strongly opposing 



* Prodrome d'une Nouvelle Distrib.,Bull. des Science, 1816. 

 | Philosophic Anatomique ; and Quart. Jour. For. Med. for 1821, p. 35. 

 % Intr. iv. 395-6. § Mem, des Anim. sans Vertebres, pt. i. 



