GENERAL VIEW OF THE SKULL, 



39 



urch, which is semi-elliptical in form, aud marks the entrance to 

 a large cavity above called the nasal chartxber ; this cavity is in 

 the fresh state, divided into right and left compartments or fossm 

 by a cartilaginous septum. 



Between the posterior molars and the palatine arch are the 

 two palatine foramina. Behind, and 

 bounded by the palatine arch, are the 

 entrances to the nasal chamber, right 

 and left, called the posterior nares, 

 and the slender median bone stretch- 

 ing from behind forwards in the cavit}' 

 is the vomer ; it indicates the division 

 of the chamber into right and left 

 fossae. Continuous with the vomer 

 we find an irregular column of bone 

 reaching to the back of the skull ; 

 this column consists of three pieces, 

 the pre-sphenoid anteriorly, then the 

 basi-sphenoid, and lastly the basi- 

 occipital bone. These bones are 

 respectively parts of the sphenoid and 

 occipital bones, and they, together 

 with the vomer, are regarded as the 

 centra of the cranial vertehrce ; and 

 the ossified suture between the last 

 two bones is usually marked by a 

 roughened ridge. 



On the posterior edges of the pala- 

 tine arch are two small sharp projec- 

 tions, the ends of the pterygoid bones, 

 and behind them the rough palatine 

 ridges, the posterior edges of which 

 are formed by the pterygoid processes 

 of the sphenoid bone ; outside the 

 base of each of these processes we 

 have the posterior aperture of the 

 suh sphenoidal or pterygoid foramen, which gives passage ta 

 an important artery. There are two large, rounded, and may be 

 roughened prominences, the alveolar tuberosities, immediately 

 behind the last molar teeth, and between them and the palatini 

 ridges and pterygoid bones are the smooth staphyline grooves. 



Fig 11 

 Inferior aspect of Hoises skull, 

 the mandible being removed. Above 

 the line A is the posterior region or 

 base, between A and B the middle, 

 aud below B the anterior or nasal 

 region, a. Occipital condyle ; b, Fora- 

 men magnum ; c, Styloid process ; 

 d. Temporal articular surface ; e, Basi- 

 occipital, and/, Basi-sphenoid bones ; 

 g, Petrosal bone ; h, Ali - sphenoid 

 bone ; i, Temporal bone ; fc. Condyloid 

 foramen ; fc' Condyloid notch ; I, Fora- 

 men lacerum basis cranii ; m. Ptery- 

 goid foramen ; n. Palatine suture ; 

 o, Palatine foramen ; p, Molar teeth ; 

 q, Incisive opening ; r. Foramen 

 incisivum. 



