INTR OD UCTION. 5 



by a study of the development and fall of the antlers 

 of deer when compared with changes which occur in 

 bone as a result of injury. 



Bones are clothed externally by a membrane termed 

 periosteum ; this membrane serves as a matrix in 

 which blood-vessels ramify before entering the compact 

 tissue of the bone. It must be remembered that bone 



FlG. 2. The head of a female Moose (Alces machlis] ; the antlers 

 are in " velvet." 



is not only dependent on the periosteum for nutrition, but 

 the deeper layers of this membrane have bone-forming 

 properties ; the increase in thickness of a long bone is 

 due entirely to the periosteum. Should the periosteum 

 be injured and inflammation established, a local increase 

 in its bone-forming function is the result, producing a 



