302 Diseases of Bone. 



and roughened by marks of numerous blood-vessels. Corre- 

 sponding to the deficiency on the outside, there is a smooth 

 necrosed portion of the inner table perforated by the trephine, 

 and surrounded by a raised margin of thickened bone. It is 

 triangular in shape, and leading from the apex of the triangle, 

 and parallel with the coronal suture, is a deep groove upon a 

 raised ridge of bone. In the absence of any clinical history 

 the explanation of those appearances, which differ from those 

 of most of the ordinary specimens of syphilitic disease of the 

 cranium, is difficult. G. C. 369. 



6. 259. Syphilitic Disease of the Skull, leading* to 



Necrosis. — Skull-cap, probably of a woman — macerated, 

 illustrating the above. 



From the vertex forwards the changes are more and more 

 marked. Except on the necrosed part in front, and on the 

 margins round it, the irregularities of the roughened surface 

 have all been smoothed over. Some smoothing over is per- 

 ceptible, even on the necrosed part itself, from which it would 

 appear that the necrosis had resulted from a recrudence of the 

 disease after the subsidence of a former attack. 



About the level of the frontal eminences a mass of very 

 irregular, apparently necrosed bone is in process of separation. 

 It measures two and a half inches by one and three-quarter 

 inches, and lies obliquely across the forehead. The groove 

 round it penetrates the thickness of the skull completely at the 

 upper and left parts, and in places below, but on the right side 

 the groove does not go deeper than the diploe. For the most 

 part the edges of the grooves overhang the dead part. 



On the inside there is likewise a groove round the dead 

 part, and this aspect of it is as rough and irregular as the outer 

 one. There are marks of increased vascularity all over the 

 interior of the vault, but especially in front. The section of 

 the bone is greatly thickened in front of the necrosed area, but 

 elsewhere it is thin, B. C. i. 7. M. 15. 



