THE LIFE OF MAMMALS 
manner, dropping on their knees at every shock; then quickly wheeling 
about they kick up their heels, whirl their tails with a fantastic flourish, and 
scour across the plain enveloped in a cloud of dust.” 
The “antelope” of the North American plains stands in a 
family (Antilocapride) by itself, on account of the singular 
structure of its horns, which make the name prong- 
horn far more appropriate. Its nearest relative 
among us is the white goat; but it has no false hoofs, and is 
unlike any other sheathed-horned creature in that its horns are 
branched, in the way their covering is acquired, and most of all 
in the fact that they are periodi- 
cally shed and renewed. All to- 
gether it is the most singular of 
ruminants. 
Pronghorn. 
The skull is surmounted by two spike- 
like horn cores, rising over, not behind, 
the great eye orbit and leaning outward. 
These are covered with a skin and coat of 
bristly hairs which agglutinate at the tip 
and change into a sheath of horn, the 
change proceeding toward the base until 
the bony cores are sheathed with horns 
which stand about a foot in height, are 
curved inward, so as often to be truly lyrate, and have one prong (occasion- 
ally more) on the front edge. Every winter these horns are pushed off by 
a new hairy growth beneath them, comparable to the ‘‘velvet” of deer’s 
antlers, which in turn hardens into another pair of true horns. It was not 
until about 1865 that the fact of the shedding of the horns, which had been 
long before asserted by Indians and plainsmen, was admitted by ‘“‘the 
faculty”; Audubon declared he had ‘‘proved to the contrary.’ To Dr. 
Caton 7 belongs the credit of tracing the full process. The affinity of 
the pronghorn to the deer, suggested by this fact, becomes more apparent 
when it is recalled that in the Miocene era there lived in our 
West a group of small, graceful plains runners called now 
deer-antelopes, because, with the general structure of antelopes, they 
bore on their heads branching antlers of the American type, 7.e. round, 
equally forking, and without a brow tine; but these antlers rose from right 
286 
PRONGHORN 
Growing horns, showing the 
hardening at the tips. 
Merycodus. 
