158 HISTORY OF THE WORKS OF CUVIER. 



thick and broad cartilaginous plate, without any ver}'^ distinct vestig-e of the pos- 

 terior branches, and a single ossified piece, representing the anterior branches. 

 The hyoid of lizards is much more coin])lex, and that of the tortoise even more 

 so than that of the lizard. * * * Bnt it is in the batrachians, chiefly, that 

 the hyoid acquires importance, and thus leads by degrees to the hyoid of lishes, 

 so rich and complicated. To explain tliis richness of the hyoid apparatus in 

 fish, recourse had been had to a pretended intercalation which hae? taken place 

 of pieces borrowed at once from the sternum, the larynx, and the ribs. It will 

 be perceived that the metamor})liosis of the frog, which, in its first period, respires 

 by brouchicS or gills, like the lish, which at a later period resi)ires by lungs, like 

 the land animals, and the bronchial apparatus of which changes by degrees, 

 and visibly, into a true hyoid, should have settled all difficulty in this respect. 

 M. Cuvier, therefore, made this singular metamorphosis a detailed study ; he 

 followed it in its whole progress ; he saw the branchiae and branchial arches suc- 

 cessively fall ; he saw the proper hyoid of the adult frog take shape proportion- 

 ably ; and at no time, even at that of the greatest complication, when the bran- 

 chial arches and the branchise existed, neitlier did the sternum nor the larynx 

 take, nor could the}* take, any part in this whole composition ; for the branchial 

 apparatus still very distinctly exists, with all its parts, which are clearly to be 

 seen, as well as the larynx, Avith its dependent lungs, and the sternum, with 

 the bones which rest against it. The hyoid of the salamander is metamorphosed 

 like that of the frog, and the branchial apparatus, in the same way, still very 

 distinctly subsists, although the larynx, the lungs, and the sternum, are also pres- 

 ent; and all this acquires new force from what is observed so plainly in the 

 axolotl, the proteus, the siren, animals in which the branchial apparatus exists 

 simultaneously, and in a constant manner, wath the larynx, the tracheal artery, 

 &c. The branchial apparatus is, therefore, only a more complex hyoidian ap})a- 

 ratns, and not one resulting from the combination of parts foreign to it, and 

 derived from neighboring organs. 



Each apparatus has, therefore, its proper constitution ; it has its marked incre- 

 ments and decrements ; its parts change from one class to another in form, in 

 number, in complexity ; and it is these very changes which determine the organic 

 characters of classes, of orders, of genera, of species. What, then, must be 

 understood by miiti/, or, to speak more exactly, by conformiiy of organisation^ 

 by conformity of plan, in the vertebrate animals, at least in what regards their 

 osseous system, if not an assemblage of graduated analogies, more constant in 

 the essential apparatus, more variable in the accessory, and of which the limit 

 cannot be given, for each appai'atus, except by the direct and consecutive study 

 of all the modifications of that apparatus, in all the classes? Kow this consecu- 

 tive study of an apparatus through ail the classes, and of all the graduated mod- 

 ifications Avhich it undergoes from one class to another, is })recisely what consti- 

 tutes the most distinctive feature of Cuvier's method, and the point which ought 

 perhaps most to fix the attention of right-minded inquirers ; for it is on the rig- 

 orous and special adaptation of the method to its object, that depends the exact- 

 ness of the results. Now, what is here the question ? Of following, of recog- 

 nizing an apparatus through all its metamorphoses of number, of form, of com- 

 plication of parts. And is it not plain that to lose sight of a single intermedi- 

 ate metamorphosis would sufiice to render impossible all recognition of those 

 which follow, would be to lose the thread w'hich connects one with the other, nay, 

 to lose the apparatus itself ? The principle of successive and graduated modifi- 

 cations, employed by M. Cuvier, is one, then, of the most fruitful as well as most 

 ingenious means of investigation with which he has enriched science, and the 

 only one which can give, in a sure and precise manner, both the determination 

 of each apparatus, and the limit of its analogies or its dissimilarities in each class. 



