170 THE DEER OF AMERICA. 
although the growth is much more rapid, and when completed 
other phenomena are noticed not observed in internal bones, 
which are required by the economy of the animal, which demands 
that they complete their growth, die, and be cast off annually. 
These modifications are entirely consistent with the general plan 
of osteal structure. During the period of growth of the antler 
it is provided with a pertostewm, and with internal blood-ves- 
sels as well, though it has no medullary canal filled with marrow 
like the long internal bones. 
As: before intimated, the antlers of the deer are not persistent, 
like the other bones of the body, but they are grown from the 
beginning to maturity and then are cast away every year. 
In most cases the matured antler is cast in the fall or winter, 
but in some cases they are retained till spring. 
In those cases where the antler is dropped in the fall or win- 
ter, immediately the periosteum, which surrounds the pedicel or 
the process of the skull on which the antler grows, the edge of 
which was left naked and bleeding when the old antler was cast 
off, commences extending itself over the naked end of the bone 
which it surrounds, and which constituted the seat of the antler, . 
and in a few days at most it has closed over it, and consists of a 
thick vascular naked covering with a black cuticle, and in this con- 
dition it remains, just fairly filling the concavity which is left by 
the lower convex end of the discarded antler. This vascular cov- 
ering of the concave top of the pedicel, grows no more during the 
winter, but the blood circulates freely though moderately through 
it, maintaining about the same temperature as other portions of 
the skin of the animal which are clothed with hairs. While 
there are no hairs or fur observed on this black skin, a sort of 
scaly dandruff forms on it which the animal, if very tame, will 
allow to be gently rubbed or scraped off with the finger nail, and 
even seems to enjoy that operation. This remains in a quiet 
state till spring, when vegetation begins to shoot forth and a 
scanty supply is procured by the deer. Then those bucks which 
had carried their antlers through the winter, drop them, the old- 
est first. Then the top of the pedicel is immediately overgrown, 
as were those in which the antler had been discarded in the fall 
or winter. Then all commence rising up in a convex form, as- 
suming first the appearance of a great blood-blister. 
Now the antler commences a longitudinal growth, the top 
maintaining its convex form, while the beam attains at once its 
full diameter ; and so it grows in length but never appreciably 
