A CLINICAL STUDY OF THE SKULL. 15 



from the facts is that the right greater cornu of the hyoid bone has 

 a tendency to be pressed in against the wall of the pharynx, while 

 the left appears to have no such disposition. 



THE NORMA BASILARIS. 



The norma basilaris embraces the skull when viewed from 

 beneath. It is the least natural of any of the norrare, for the parts 

 back of the foramen magnum are included in the region of the neck 

 and are separated from the occiput by inconstant lines, while the 

 facial parts are included in the mouth. The parts intermediate 

 to the occiput and the face (the lower jaw will be considered as 

 absent) -constitute the true " base of the skull" as limited by phy- 

 sicians in studying the skull in the living individual. It includes 

 studies of the important region of the pharyngeal vault. Varia- 

 tions in the norma basilaris, as might be expected, are seen in the 

 occipital, facial, and intermediate regions, which do not of necessity 

 correlate with one another, but express oftentimes entirely distinct,^ 

 if not opposing, tendencies. 



In order properly to consider the relations of the somewhat in- 

 congruous elements of the norma basilaris it is important to recall 

 the significance of the parts. 



Taking the union of the squamosal, tympanic, petrosal, and 

 styloid elements to form the temporal bone as an illustration of the 

 fact that early union between bones is an evidence of their affinity, 

 then the following statements become tenable : 



The skull of the child at the sixth year exhibits the bones of the 

 face united completely to one another and to the sphenoid and 

 frontal bones. Thus, since they unite with the facial elements 

 sooner than with the occipital, squamosal, or frontal, they may be 

 said to have closer relations with them. The bones of the face 

 (excepting, of course, the lower jaw) unite with the sphenoid and 

 the frontal bones to form a single segment or piece, while the 

 remaining bones — the parietals, temporals, and the occipital — are 



