No. 1619. HORNS OF THE AMERICAN ANTELOPE—LYON. 397 
SYSTEMATIC POSITION OF THE AMERICAN ANTELOPE. 
Nearly all systematists have united in placing the American Ante- 
lope, Antilocapra americana (Ord), in a separate monotypic family, 
Antilocapridx, distinct from the other Ruminants, cn the ground 
that it combines in a measure the characters of deer (Cervide) and 
of oxen, sheep, goats, and true antelopes (Bovide). In support of 
this, it is pointed out that its horns are branched and shed annually, 
both characters of deer, but that it is also a hollow-horned rumi- 
nant like cattle, ete. To one who gives the matter consideration, it 
becomes clear that there is no resemblance between the horns of the 
Antelope and the so-called horns, or antlers, of the deer, and there is 
every resemblance structurally and physiologically between the Ante-. 
lope’s horns and those of the Bovide. 
The antlers of the deer are branched processes of the frontal bone, 
shed and renewed annually. Each antler is supported on a distinct 
and permanent outgrowth of the frontal bone known as the pedicle. 
The base of the antler where it is attached to the pedicle is marked 
by an outgrowth or ring of bone known as the burr. When the 
antler is about to be shed, the bone at the junction of the antler with 
the pedicle is absorbed and the antler falls off. The skin which per- 
manently covers the pedicle immediately grows up over the upper 
surface of it. From the top of the pedicle the new antler grows out, 
being always covered with the growing skin from the pedicle. This 
skin is very vascular and covered with velvety hair. The growing 
antler itself is very vascular in its interior so that the bone of which 
the antler is composed is rapidly formed. When the antler reaches 
maturity, the blood supply to the skin covering it is gradually 
diminished so that it dries up and eventually peels off, leaving the 
naked bone of the mature antler exposed. The development of the 
burr at the base of the antler probably assists in cutting off the sup- 
ply of blood to the velvet of the antler. The blood supply to the 
antler itself in the interior is gradually diminished, so that by the 
time the antler is to be shed it has become practically so much dead 
bone. 
In the Bovide, and in the American Antelope as well, the horn is 
an epidermal outgrowth of definite material known as horn sup- 
ported by a well-developed process of the frontal bone beneath it 
known as the horn-core. This latter is permanent, never cast off, 
and is simple and unbranched, but conforming more or less to the 
shape of the horn which it supports. The horn proper, the epider- 
mal outgrowth, is added to annually. In the typical Bovide the 
annual increment is not cast off and can be seen at the base of the 
horn in the form of the well-known annual rings. In the Ante- 
lope the annual increment is cast off each succeeding year and no 
