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 laniina3 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- 

 vidse, 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 tlie in- 

 vestigations already made. 



As has been already said, tlie 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 a deer'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 man}' 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. 



