16 PRACTICAL ANATOMY. 



the convolutions of the brain, and also presents several 

 grooves, which are best marked and most constant near 

 the anterior inferior angle. The grooves lodge the 

 middle meningeal artery and its branches. The superior 

 border is slightly beveled at the expense of the inner 

 surface, and, when the bones are articulated, it assists in 

 forming a groove which lodges the continuation of the 

 superior longitudinal sinus. Depressions for the Pacchi- 

 onian bodies are also observed. The superior border 

 articulates with its fellow in the middle line of the skull, 

 forming a deeply serrated and denticulated suture. The 

 anterior border articulates with the frontal bone by tooth- 

 like processes, which firmly interlock with similar proc- 

 esses of the frontal bone. The anterior inferior angle, 

 with part of the inferior border, articulates with the great 

 wing of the sphenoid. The inferior border is concave, 

 and is beveled on its outer surface to articulate with the 

 squamous portion of the temporal ; posteriorly the in- 

 ferior border articulates with the mastoid portion of the 

 temporal bone. The posterior border articulates with 

 the occipital by means of well-marked dentate processes. 

 The parietal bone develops from one centre, which 

 appears about the third month. 



THE OCCIPITAL BONE. 



The occipital bone is situated at the back and base of 

 the skull. It is strongly curved, forming an arch of 

 about one-third of a circle. Viewed posteriorly it is 

 diamond-shaped. It presents for examination two su- 

 perior lateral and two inferior lateral borders, an exter- 

 nal and an internal surface, and a basilar process. The 

 superior borders meet above at the apex of the bone, and 

 articulate with the posterior borders of the parietal bones 

 by means of tooth-like processes. The inferior borders 



