FOSSIL REPTILES. 171 



sary to steer clear of the errors attendant on preconceived theo- 

 ries. This rock, the Baron, with his usual judgment and caution, 

 has particularly avoided. He neither pretends to find a per- 

 manent recurrence of the same number of osseous pieces, nor 

 representations in the head of the other component parts of 

 the corporeal system. Neither does he attempt to maintain 

 that the bones of the head are absolutely the same in all the 

 genera^ but he endeavours to ascertain how far their corre- 

 spondence extends, and what are the precise limits of its pro- 

 gress. For this purpose, he commences with that oviparous 

 quadruped, which, in the head at least, affords the most sen- 

 sible analogies with the mammifera : this is the Crocodile. He 

 points out the bones which correspond with our own, and, in 

 establishing this correspondence, he consults not merely their 

 position, but also the muscles which are attached to them, the 

 nerves, vessels, &c. He candidly instances the bones which 

 escape this analogy ; shews where a bone, a foramen, a facet, 

 a suture, appear to be wanting, and where some new one is 

 to be found. 



On this principle he proceeds through all the genera. 

 Having no necessity to represent things otherwise than they 

 are, he neither employs vague propositions nor figurative ex- 

 pressions, which have proved so fertile of self-illusion to the 

 ablest writers. Thus, though the results he arrives at are not 

 so calculated to dazzle the imagination as theirs, they satisfy 

 the judgment, from their consistency with facts. 



A development of the bones of the head, in treating of the 

 crocodile, becomes of the greatest importance, for when this 

 is done, the study of those of the tortoises, lizards, and cro- 

 codiles, is comparatively easy. With the batracian reptiles, 

 indeed, the case is a little different. 



The bones of the shoulder and the sternum in the lizard 

 require considerable attention, as there is a greater degree of 

 complexity attached to them. 



The hyoid bone in the batracians is of the greatest impor- 



