26 THE ANTELOPE OF AMERICA. 
to the men at the fort by knocking off the bony part of the horn 
and showing the hard spongy membrane beneath, well attached 
to the skull, and perfectly immovable.” 
The hunters were right, and the scientists were wrong; but 
we see how near Mr. Audubon came to discovering the truth, 
and had he been a little more patient in his investigations, and a 
little less wedded to preconceived opinions, he would have had 
the honor of this important discovery. But that was reserved 
to others. 
Some years later, on the 10th of April, 1828, Dr. C. A. Can- 
field, of Monterey, California, in a paper which he sent to Pro- 
fessor Baird of the Smithsonian Institute, communicated many - 
new and interesting facts concerning the physiology and habits 
of this animal ; and, among others, the surprising announcement 
that although it has a hollow horn, like the ox, yet this horn is 
cast off and renewed annually. This statement by Dr. Canfield 
was considered by Professor Baird so contradictory to all zodlog- 
ical laws, which had been considered well established by ob- 
served facts, that he did not venture to publish it, till the same 
fact was further attested by Mr. Bartlett, superintendent of the 
gardens of the Zodlogical Society of London, who, in 1855, re- 
peated the fact in a paper published in the Proceedings of that 
society. In the February following, the paper which Dr. Can- 
field, eight years before, had furnished the Smithsonian Institute, 
containing the first well attested account of the interesting fact, 
was published in the Proceedings of that society. 
At the time I gave an account of Mr. Bartlett’s observation, 
in a paper which I read before the Ottawa Academy of Natural 
Sciences in 1868, and which was published by that society, I was 
not aware that the same fact had been previously communicated 
by Dr. Canfield to Professor Baird, else I should have taken pleas- 
ure in mentioning it. 
This animal has a deciduous hollow horn, which envelopes a 
persistent core, which is a process of the skul! like the core of the 
persistent horns of other ruminants. This shell is true horn, 
and, as we shall presently see, has the same general system of 
growth as other horns, although it is cast annually like the 
antlers of the deer, and so reveals to us an intermediate link be- 
tween those ruminants which have persistent and those which 
have, deciduous corneous appendages. Only the lower part of this 
horn is ‘hollow, the core extending up scarcely half its length. 
When the horn is matured, the portion above the core is round 
