58 THE TONER LECTUEES. 



tinctly separated as ou the exterioi% and, as the interior plane of 

 the sagittal suture tends to remain open when the exterior is closed, 

 the evidence of the disposition is here often alone available. 



The side of least expansion of the j^arietal bones correlates with 

 increase of thickness of the inner plate. The elevation of the 

 inner plate of the unexpanded side is easily detected by the finger. 



In No. 24 of the College of Physicians the vertex-sutures are 

 open, the bregmal, post-bregmal, obelial, and post-obelial parts are 

 serrated, both exteriorly and interiorly, while the intertuberal (the 

 post-bregmal portion being here counted a separate quantity) is 

 harmonic. 



In No. 50, of the same collection, the interior view of skull is har- 

 monic throughout, the bregmal being alone distinguished by its 

 obliquity to the rest of the sagittal suture. 



The relations of the depressions (presumably for the Pacchionian 

 bodies) are, if of simple form, very commonly on either side of the 

 intertuberal portion of the suture at the post-bregmal division. In 

 thirty examinations of normal crania I have found but five where 

 the depression was either absent or merged wdth a depression placed 

 still farther back. 



When the vitreous plate is thickened at the region of the former 

 anterior fontanel and extends along the lines of the sutures so as 

 to form a lozenge-shape figure, depressions for the Pacchionian 

 bodies are often seen at its sides. It is rare to see depressions at 

 the obelial or the post-obelial parts, though they may be oftener 

 found on the frontal bones below the frontal eminences.- Between 

 the parietal tubera and the sagittal suture at the obelion an emi- 

 nence is frequently found which almost equals the tuber in size. 

 It is very commonly found in the skulls of Peruvians. 



As in all other anatomical quantities, the subdivisions of the 

 sutures of the vertex are subject to variation. 



The simple statement upon which such subdivisions may be ren- 

 dered tenable is one universally conceded, namely, that structures 

 in their range of variation show traces of their origin and rates of 



