INTRODUCTION. 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 
Fic. 2.—The head of a fernale Moose (A/ces machlis) ; the antlers 
ce 
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 
