4o2 THE MECHANICAL FUNCTIONS. 



they at lengtli become entirely obliterated. The 

 bone, no longer receiving- a superabundant nourish- 

 ment, ceases to grow ; the integuments, which co- 

 vered it, decay, and becoming dry and shrivelled, 

 are torn by rubbing against trees, and peel off in 

 long shreds, leaving the antler exposed, which, by 

 the continued effects of the same kind of friction, 

 soon acquires a polished surface. 



During many months, the antler being suffi- 

 cientl}^ nourished by its own interior vessels, con- 

 tinues in a living state, and preserves its connexion 

 with the system. But at length the arteries, whe- 

 ther from the effect of the progressive deposition of 

 osseous matter, or from some change in the balance 

 of the vital powers, shrink and become by degrees 

 obliterated. The antler dies in consequence, and 

 although it continues to adhere to tlie skull, it is 

 only as a foreign body ; and it is not long destined 

 to remain thus attached ; for the absorbent vessels 

 are now actively employed in scooping out a groove 

 of separation between the living and the decayed 

 substance, at the place where the base of the antler 

 is contiguous to the frontal bone. As soon as this 

 has proceeded to a sufficient depth, the adhesion 

 ceases ; and the slightest concussion occasions the 

 fall of the whole structure. After the separation of 

 the antler, the eminence of the frontal bone on 

 which it stood is left rough and uneven like that of 

 a fractured part: but the surrounding integuments 

 soon close over, and cover it completely ; until the 

 period arrives when it is to be replaced by a new 

 antler, which exhibits the same succession of phe- 

 nomena in its growth and decay as its predecessor, 

 only that its developement is usually carried far- 



