300 Diseases of Bone. 



The reason for the trephine opening does not appear. The 

 specimen shows an irregular piece of necrotic bone partially 

 entrenched round, and with vascular channels in process 

 of opening out extending bej'^ond. The inside shows some 

 enlargement of vascular pores. The diploii is condensed. The 

 margin of the trephined aperture shows that the above patch of 

 bone was being undermined from below as well as from the 

 sides. AY. C. G. 47. 



6. 255. Syphilitic Disease of the Skull, with Necrosis.— 



Skull-cap of an old person — macerated, illustrating the above. 



The outer surface at the top shows roughness, chiefly from 

 the increased size of the pores for blood-vessels. Above the 

 right frontal eminence is a depression with a raised margin. 

 The edges are rounded off, as if the part had been healing. 

 Below the left parietal eminence an area of one and a half 

 inches by three-quarters of an inch has been in process of 

 separation, and is entrenched round by a distinct groove. The 

 surface of this piece is porous and rough, as in other cases 

 of sj'-philitic necrosis. Below the right temporal ridge the 

 parietal bone has been trephined for reasons unknown. On 

 the inside, below the mark near the right frontal eminence, 

 there is a distinct thickening of bone, with marks of increased 

 vascularity. Beneath both parietal eminences, especially the 

 left, there are marks of increased vascularity. The diploe 

 is condensed, and the bone is much increased in weight. The 

 posterior part of the sagittal suture is entirely obliterated. 



B. C. I. 7. M. 11. 



6. 256. Syphilitic Disease of the Skull, with Necrosis.— 



Portion of a parietal bone — macerated, illustrating the above. 



A small necrotic piece, which is eroded on the surface, is 

 partly undermined as well as grooved round. The interior of the 

 bone shows marks of increased vascularity, and the diploe is, 



