42 ON DENTAL EXOSTOSIS. 



as in the cases above mentioned, I can see no reason 

 for hesitating to assign to the hypertrophied tissue 

 the same mode of formation. 



Upon examining the periosteum of a stump or 

 tooth recently drawn which has been the subject of 

 long-continued irritation, we find it much more 

 vascular than usual ; in some places it is very much 

 thickened and slimy, and very frequently adhering 

 to it are reddish fleshy shreds or masses, which 

 have been called coagulated lymph (Figs. 4, 5, 6, 

 Plate V). These are sometimes of comparatively 

 large bulk (Fig. 5), especially where this has 

 been the subject of recent inflammation ; and it not 

 only follows that the tooth must be elevated in its 

 socket, but that even the latter must be itself exca- 

 vated to accommodate the morbid growth. In Fig. 

 b, Plate y., the stump is imbedded in an immense 

 mass of this coagulated lymph, and the walls of the 

 alveolus, having to be removed for its accommoda- 

 tion, have softened during the process, so that a 

 piece of living spongy bone has been brought away 

 with the mass. And in order to assist our concep- 

 tion of this fact, I may here remark upon the ex- 

 traordinary facility with which the jaw-bones change 

 their shape. An alveolar abscess hollows them out, 

 and drills a hole through them in a few days ; or two 

 or three double teeth are extracted, and in a few 

 months not a vestige of their former implantation is 

 visible, and they will slowly expand before a tumour, 

 covering it with a thin papery envelope, rapidly to 



