178 THE DEER OF AMERICA. 
the blood-vessels which had been compressed now swell out and 
become active conduits for the required nutriment for the new 
growth, and everything which had been for several months so 
dormant suddenly becomes the scene of intense activity. Then 
again, as this new growth approaches completion, and the neces- 
sity for this great supply of nutriment diminishes, a new deposit 
of earthy matter takes place, new lamine are formed within these 
canals so lately opened by the absorption of the old, the blood- 
vessels are again gradually diminished, and finally practically 
closed, when their active functions are no longer required. 
Thus we see how complete is the system, and how perfectly 
adapted is it for the anomalous requirements, to supply the nutri- 
ment, for the rapid growth of the deciduous antlers of the Cer- 
vide, and a perfect comprehension of this will enable us to 
understand the remarkable phases, under varied circumstances, 
which it will be necessary to explain before we complete our 
present subject. 
A more particular description of the progress of this growth is 
now necessary, and we are the better prepared for this by the in- 
vestigations already made. 
As has been already said, the first structure is of the outer 
walls, or circumference of the antler forming a hollow cylinder, 
the cavity being in the form of an inverted cone, The specimen 
before me is adeer’s antler less than half grown, and is six inches 
long and one inch in diameter. The ossified walls do not extend 
to the top, which consists of a mass of blood-vessels, the osseous 
wall at the upper end presenting a thin serrated edge, the cavity 
there being nearly one inch in diameter. Below this the wall 
gradually increases in thickness, and is composed of cancellous 
tissue, more dense towards the circumference; just above the 
burr, the cavity is nearly filled with this tissue, through which the 
blood-vessels pass, with a small open passage near the middle. 
The internal cavity does not entirely terminate at the seat of the 
antler, but continues down into the pedicel in the form of a canal, 
where it soon spreads out into many ramifications, whence come 
the tributaries transmitting the great flow of blood which passes 
through that channel for the nourishment of the rapidly growing 
antler. 
The butt or lower end of the matured antler is more or less con- 
vex, corresponding to its concave seat at the top of the pedicel. 
This lower extremity of the antler, where the articulation occurs, 
is, as before intimated, exceedingly compact, corresponding, in 
that respect, to the articulate extremities of the internal bones. 
