34 THE ANTELOPE OF AMERICA. 
year when the formation of new cells upon the papille increases 
to a degree commensurate with the demand. 
This increased activity first commences at the upper part of 
the core, where the new horn commences its growth. Here the 
demand is greater than ever occurs lower down on the core; here 
an increased flow of blood stimulates to a more rapid formation 
of cells, which are successively forced up, flattened, and arranged, 
sufficient to form a considerable part of the cylindrical portion of 
the horn before any great activity is observed below, and these 
act with sufficient force to lift the horn from its seat, tear asunder 
the hairs which connected it with the skin, and finally cast it off. 
An active circulation is still kept up through this newly-formed 
cylinder, which is still somewhat soft and flexible, and quite 
warm, which, however, gradually dries up and hardens into the 
perfect horn, at the upper part first, and progressing downward. 
Now the peculiarity about this is, not that the epidermis is the 
source of the horn, or is converted into horn, but that a very lim- 
ited section should be stimulated to extraordinary activity till its 
work is accomplished, and then subsides into a comparatively dor- 
mant state; and then another portion wakens to the same vigor- 
ous action, to be again succeeded by another active section still 
lower down ; this state of activity commencing at the top of the 
core and gradually passing along down it, followed by the per- 
fected horn, and the quiet condition of the epidermis lining its 
cavity ; and that this extraordinary phenomenon should occur 
annually. The horn from the epidermis was to be expected, for 
the cells when forced to the surface of the cuticle on our own skin 
even, are always of a horny texture, and in that condition are 
worn away by friction, or are thrown off, with greater or less 
rapidity, and are succeeded by those beneath, which are brought 
- to the surface to be thrown or worn off in their turn; but in the 
ordinary cuticle this process is regular and continuous, while this 
is spasmodic, or rather periodic. 
The horn of the ox grows from the cuticle as well as this, but 
it is of slow and regular growth, and is pushed up from its base, 
while this horn grows from the top downward, taking up or con- 
verting in its progress the epidermis all the way down the core. 
While the growth of this horn is undoubtedly on the same prin- 
ciple as the growth of all other horns, here is an important modi- 
fication of tlie process rendered necessary by the deciduous char- 
acter of this horn. Its growth must be characterized by extraor- 
dinary energy, when it is to be accomplished in a few months’ 
