and on the Geological Position oj their Fossil Memaitis.^Bi 



tion in question ; and I mark where it appears to present anew 

 the same relation. Having no occasion to display things 

 other than they are, I employ neither those vague propositions 

 nor those figurative expressions by which I might deceive 

 myself, as has happened to so many other individuals of the 

 strictest integrity of mind : and if, by these means, I arrive not 

 at such brilliant results, I flatter myself that I tread a more so- 

 lid path. 



Witli respect to the head, it is, as I have above observed, 

 upon tlie Crocodile that I have found it necessary to insist the 

 most ; for, tlie bones of this animal once named, we find it 

 easy to name those of the Tortoises, the Lizards, and the greater 

 part of the Serpents: but a new and more difficult study be- 

 comes necessary in considering the Batracian tribes. 



The bones of the shoulder and the sternum must be stu- 

 died, especially in the Lizards, in which they present the great- 

 est degree of complication. 



In regard to the os hyoides, it is among the Batracians that 

 it possesses the most importance ; since it there furnishes us 

 with the means of forming clear ideas upon that of Fishes; on 

 whicli subject numerous and very diversified systems have been 

 conceived. 



Upon this point, I trust that the facts adduced in this part 

 of my work, and especially the successive simplification and 

 ultimate disappearance of the auricular apparatus, as well as 

 the gradual development of the hyoidal apparatus, in the Ba- 

 tracians, notwitlistanding the presence of a larynx and a ster- 

 num, will lead us back to the former views, — those which I 

 have constantl}' announced, — that the bones of the ear do not 

 re-appear in osseous Fishes in the form of opercula ; that the 

 branchial apparatus, in order to present the complication 

 which characterizes it, has no need of completion by means of 

 intercalary sternal, laryngial, or costal pieces; and, finally, 

 that the opercular apparatus is one which is in itself special, 

 and proper to the species in which it is discovered. 



I will here add but one word on the other parts of the body ; 

 which is, that the particular sections which constitute each 

 part, so far from being multiplied like those of the head, have 

 not, in the infant state, those productions at their extremities 

 which we call epiphyses. 



In the Crocodiles and Tortoises, the extremities of the bones 

 and their principal eminences arc overlaid or surrounded 

 with cartilages, which harden and ossify with age; but in which 

 there is not formed, as in the Mamniifera, an osseous kernel, 

 .separated for a time i'rom the bone itself, or from the diapliy- 

 sis, by n suture ; a circumstance (he more remarkable, from 



tlie 



