REPRODUCTION OF BONE. 465 



XXXI THE MODE OF KEPKODUCTION AFTEK 

 DEATH OF THE SHAFT OF A LONG BONE. 



THE question at issue regarding the source of the new osseous 

 substance in regeneration of the shaft of a long bone, is thus 

 stated by Professor Syme.* "Whether the periosteum, or 

 membrane that covers the surface of the bones, possesses the 

 power of forming new osseous substance independently of any 

 assistance from the bone itself?" and the Professor has de- 

 tailed some very ingenious experiments, which satisfied him 

 that this membrane does possess the power of producing new 

 osseous texture. 



The first experiment consisted in exposing the radius of a 

 dog, and removing an inch and three quarters of it along with 

 the periosteum ; and in the other leg removing a correspond- 

 ing portion without the periosteum. In six weeks the cut 

 extremities of the radius, from which a portion had been taken, 

 together with the periosteum, had only extended towards one 

 another in a conical form, with a great deficiency of bone 

 between them, and in its place merely a small band of tough 

 ligamentous texture. In the other, where the periosteum had 

 been allowed to remain, there was a compact mass of bone, 

 not only occupying the space left by the portion removed, 

 but rather exceeding it. 



The objection to this experiment is, that it cannot be 

 performed accurately. I have satisfied myself, that it is 



* Trans. Roy. Soc. Edin. vol. xiv. page 158. "On the Power of the 

 Periosteum to form New Bone." 



2 H 



