848 
AKTIODACTYLA. 
of spongy material, witli an irregular surface devoid of dense layer. It is 
worn as thougli it had been softer than the remainder of the bone, and looks 
as though its vitality had been lost. In another specimen of D. furcatus^ 
the extremit}^ of an antler had been broken otf, and, slipping down so as to 
overlap the fixed end for half an inch, had reunited by anchylosis without 
throwing out any burr. 
I had at one time suspected that a fracture of the base of the beam 
had caused the deposit of the burr, and the rugose band surrounding the 
former beneath the latter has much the appearance of a surface of reunited 
bone. On making sections of two beams of B. furcatUs^ which display 
the annulus, I find no indication of fracture during life, as both the denser 
and coarse central tissues are uninterrupted (see fig. 7, pi. Iviii, and fig. 1, 
pi. lix). 
From the facts of the case, the following inferences may be derived, 
premising that it is very probable that a genus allied to the present one 
gave origin to the family of the Deer. It is obvious that the horns of 
Bicrocerus did not possess a horny sheath as in the Bovidce, from the fact 
of their being branched. As the sheath grows by addition at the base, the 
presence of branches, which necessarily obstruct its' forward movement, 
would be fatal to the process. There is much to be said in favor of the 
view that the horns were covered with an integument, probably furred, as 
in the Giraffe and young of the Deer. Thus there are grooves on the beam 
for superficial blood-vessels, which must have been protected by skin. (I 
do not observe these grooves on the beam of B. teres.) The retention of 
the broken extremity of an antler so as to be reunited as aboved described 
could not hav,e been accomplished without an integument. The presence 
of the burrs cannot be accounted for on any other supposition, as there are 
no foramina to give exit to nutritive vessels at the points where they exist; 
the irregularity of those positions forbids the latter idea, and adds to the 
probability that the arteries which furnished the deposit of phosphate of 
lime were contained in a superficial dermal coating. The supposition is 
also strengthened by the fact that the only existing Ruminants, the Giraffes, 
with permanent horns without horny sheaths, have them covered with 
hairy skin. 
