30 THE ANTELOPE OF AMERICA. 
which was already tipped with perfected horn, and a section 
below it was more or less hardened, or partially converted into 
horn. ‘This intervening section gradually moved down the horn, 
constantly invading the soft skin below, and followed above with 
perfected horn. All this time the horn was growing in length 
above the core, and assuming that posterior curvature near its 
upper part which so much resembles the curvature of the horn of 
the chamois. After the horn is perfected down to the top of the 
core, it ceases to increase in length, while the apparently convert- 
ing process steadily progresses downward along or around the 
core. The core being laterally compressed, the horn assumes 
that form, not, however, conforming precisely to the shape of the 
core, but extending considerably in front of it, where it is thinner 
than the posterior part. 
At the upper extremity of the wide, flattened part the snag 
or prong is thrown out, which consists of little more than an 
abrupt termination of the wide part, with an elevated anterior 
point. 
By the latter part of winter, on the adult, the horn has at- 
tained about this stage of growth. From this.it presses on, hard- 
ening in its downward growth till the latter part of summer, or 
the commencement of, the rut, by which time the growth is per- 
fected down to the base, and is a complete weapon for warfare, 
and it so continues during the rut, and until the growth of the 
new horn is commenced and loosens the old one from its core, 
and raises it froin its seat, as has been described. 
But science is by no means satisfied with these superficial ob- 
servations. It is exceedingly interesting to watch the progress 
from day to day; to observe how the old horn is thrown off and 
the new one grows on to perfection ; but we desire to know how 
it is that the soft warm skin, everywhere permeated with blood- 
vessels, in a very high state of activity, appears in so short a 
time to be converted into the black, hard shell, as perfect horn 
as grows upon the buffalo or the antelope, which takes a lifetime 
to perfect it. In this investigation I am indebted to the able 
assistance of Professor Lester Curtis of Chicago, whose superior 
instruments and skill with the microscope, readily solved what 
appears to the superficial observer so exceptional, and I may add 
so wonderful. We found, however, that this growth is not so 
exceptional after all. It is like the growth of the horns of other 
ruminants, like that of the hoofs and claws of animals, and of the 
nails on the human subject. And it is only because of its rapid 
