O- XL 



THE MODE OF REPRODUCTION AFTER 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 mem- 

 brane 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 detailed 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 corresponding 

 portion without the periosteum. In six weeks the cut extre- 

 mities of the radius, from which a portion had been taken, to- 

 gether with the periosteum, had only extended towards one an- 

 other in a conical form, with a great deficiency of bone between 

 thenij 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 



* Trans. Roy. Soc. Edin., Vol. xiv., page 158. " On the Power of the Periosteum to 

 form New B<me" 



