70 THE MODE OF REPRODUCTION AFTER DEATH 



striking is this peculiarity, that it will at once recur to those who 

 have had an opportunity of observing new shafts in an early 

 stage of formation ; as well as the remarkable contrast between 

 the smooth hard portions of the dead or dying bone and the 

 nodulated scales lying in the separated periosteum, alternating 

 with the former, and concealing from direct view the rough or 

 ulcerated portions of the dead shaft. In those instances in which 

 the shaft has died, with the exception of a ring or small portion 

 at each or one end, close to the epiphysis, the new bone shoots 

 in stalactitic masses in the longitudinal direction, their course, 

 direction and magnitude corresponding to the forms of the rings 

 or portions of ulcerated bone in the old shaft. This is an un- 

 favourable form of necrosis, in consequence of the difficulty en- 

 countered by the extremities of the new shell in meeting in the 

 centre, and the length of time required for the process of rege- 

 neration. This form has also given rise to a mistaken view of 

 the source of the new bone in necrosis, a belief that it is derived 

 from the epiphysis. I have never seen an instance in which the 

 epiphysis supplied the new shaft, and I have had occasion to 

 point out that the specimens on which such opinions were 

 founded are in fact exemplifications of the formation of the new, 

 from a ring or portion of the old shaft close to the epiphysis. 

 An epiphysis is a distinct part, arid has no greater tendency to 

 supply the losses of the principal mass of the bone to which it 

 belongs than the femur, fibula, or astragalus to supply the loss of 

 a tibia. 



Another remarkable peculiarity, arising from the circumstance 

 of the new bone invariably shooting from spots corresponding to 

 ulcerated portions of the dead shaft, is met with in instances 

 where one side of a dead shaft is not ulcerated, and the other 

 side, or a portion of it, has undergone that process. In such in- 

 stances, the new bone proceeds from points corresponding to the 

 ulcerations, and shoots in the form of arches across the smooth 

 portion of the old bone, meeting from either side, and giving rise 

 to new processes w r hich ultimately enclose the whole. In instances 

 of this sort regeneration is effected with difficulty, and there is a 

 tendency in the old shaft to ulcerate out on the side on which it 

 has supplied no osseous centres of regeneration. 



