Syphilitic ' Caries.' 293 



extensive changes on the inside. On the outside the parietal 

 bones near the vertex are roughened, chiefly by the enlargement 

 of the vascular pores. On the frontal bone there is also rough- 

 ening, not only by enlargement of vascular pores, but by 

 numerous small grooves on the surface, probably for blood- 

 vessels. On the inside the roughness is chiefly due to new 

 bone formation round small vascular channels, although the 

 pores for entering vessels are enlarged also. The roughness is 

 most marked on the frontal bone, and especially near the 

 middle line. At two places the surface of the inner table is 

 left exposed, and is surrounded by ragged bony spicules of 

 newly-formed bone. Possibly at these places there have 

 been gummatous deposits between the bone and dura mater. 



B. C. I. 7. M. 8. 



6. 239. Syphilitic Disease of the Skull.— Skull-cap of an 

 aged person — macerated, illustrating the above. 



The bone is roughened over both inner and outer aspects. 

 The outside shows remains of its original smoothness at one 

 or two places only, i.e. near the right frontal eminence, at the 

 temporal ridges, and near the anterior and inferior angle of the 

 right parietal bone. The roughness is due partly to the opening 

 out of vascular channels and partly to shallow depressions of 

 the surface, which are most marked at the back and on the 

 left side of the vertex. At the back of each parietal bone 

 there is a smooth patch entrenched round by a groove, as if 

 necrosis and the process of separation had already begun. 

 Inside, the roughness is very marked on the left side, especially 

 at the site of the coronal suture, but is not quite so extensive 

 on the right side of the middle line. The roughness is mostly 

 due to the development of new bone, but also to the eating 

 out of both the old and the new bone. Erosion and new 

 formation must have gone on side by side. Small apertures 

 are present near the middle of the coronal suture, and at other 

 places. B. C. i. 7. M. 10. 



