THE CRANIUM AND FACE. 49 



Where the coronal and sagittal sutures meet is a 

 membranous interval known as the anterior fontanelle, 

 while the posterior jontanelle is at the juncture of the 

 sagittal with the lambdoidal suture. These fontanelles 

 so called from the pulsations of the brain that can be 

 seen in them close after birth either by the extension of 

 the surrounding bones or by the development in them 

 of small bones known as Wormian bones , the posterior 

 one closing within a few months, the anterior by the end 



FIG. 15. Cranium at birth, showing sutures and fontanelles. 



of the second year. In rickets, however, the anterior 

 fontanelle remains open a long time, sometimes into the 

 fourth year. 



The frontal bone, as its name implies, forms the fore 

 part of the head or forehead. It joins the parietal bones 

 above and the temporal bones on either side. At the 

 lower edge are the supra-orbital arches, each with a 

 supra-orbital notch or foramen on its inner margin for 

 the passage of the supra-orbital vessels and nerve, the 

 nerve most affected in neuralgia. Just above the 

 arches on either side are the superciliary ridges, behind 

 which, between the two tables of the skull, lie the frontal 

 sinuses. On the inner surface the frontal sulcus for the 

 longitudinal sinus runs along the median line. 



The parietal bones are the side bones of the skull. 

 They meet each other in the sagittal suture at the median 



4 



