THE vKnrr.nn.iL CONSTITUTION OF THE SKELETON. 



121 



In tin- I'uiir cl;i--- s of vcrtebrata, the head is constantly formed of four 

 vertubne, which are determined us follows:" 1 



The number of cephalic vertebrae is invariable, as each is destined to 



lodge the organs of one of the four senses. The occipito-hyoideal lodges the 



principal organs of hearing; the parieto-maxillary osteodesm protects the 



of taste ; finally, the organs of vision are sustained by the fronto-man- 



diliuhir vertebra, while the naso-turbinal contains the sense of smell. 



It was therefore with reason that Geoffrey Saiut-Hilairo and Professor 

 Owen proclaimed that the typo of construction of the vertebrated animals is 

 the vertebra. 



SECOND SECTION. 

 THE ARTICULATIONS. 



CHAPTER I. 



THE ARTICULATIONS IN GENERAL. 



THK (liilerent pieces constituting the solid framework of the animal body 



i- has been said, united in such a manner that they can move one upon 



the other. From this union results the articulations or aiticular joints, whoso 



i stnietion will now bo referred to in a general manner, before commencing 



a particular description of each. 



To form articulations, the bones correspond to each other by certain 

 points of their periphery, which are named articular surface*. Every articu- 



1 Lavornt, ' Nouvelles eluded sur le systcme vertebral,' 1860. 



