THE PRONG BUCK 915 



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States. Up to the year 1855 they were abundant in California, and were not un- 

 common in the open parts of Oregon; but they have now almost if not completely 

 disappeared from both these states. In latitude their range extended from the trop- 

 ics to the fifty-fourth parallel; and within these limits they frequent by choice 

 the open prairie country, avoiding thickly-timbered districts or high, naked 

 mountains. 



That the horns of the prongbuck were shed annually was long and 

 persistently urged by the hunters of Fort Union, but these statements 

 were received with incredulity by naturalists, who scouted the idea. Eventually, 

 however, it was proved to their satisfaction that the hunters were right and they 

 themselves in error. In fully adult individuals, the annual shedding of the horns 

 usually takes place in October, but in the young the horns are retained till January. 

 In the males the horns can be felt as prominences beneath the skin even at birth, and 

 at about four months old they burst through the skin. They are later in making 

 their appearance in the females, and cannot be detected at birth. One of the best 

 accounts of the shedding and replacement of the horns is given by Mr. Caton, from 

 which the following summary is taken. On looking into the hollow of a shed horn, 

 it will be found that the cavity does not extend much above the point of bifurca- 

 tion, while it will also be noticed that the interior of the horn contains a number of 

 coarse light-colored hairs, all of which are firmly attached to its substance, while 

 in the lower part many pass completely through it. The core from which the 

 sheath was cast will also be found to be covered with similar hairs growing from an 

 investing skin, and it will thus be evident that the sheath was more or less com- 

 pletely penetrated by a number of the subjacent hairs, which were of course torn 

 asunder at the time of shedding. Indeed, the horn of the prongbuck is in reality 

 nothing more than a mass of agglomerated hairs, arid thereby differs markedly from 

 the bovine horn. 



On examining the head of a prougbuck from which the horns have been freshly 

 shed, it will be observed that the summits of the cores are already capped with 

 small new horns, which have evidently commenced their growth considerably before 

 the period of casting, as they reach for several inches above the tips of the cores. 

 The summits of these new horns are perfectly hardened, but lower down they grad- 

 ually become softer and softer, until they pass into the skin investing the greater 

 part of the core. The condition presented by an animal with newly-growing horns 

 is shown in the cut on the following page. 



It is thus clear that as the new horn gradually inceased in length above the 

 summit of the core, it must have loosened and carried with it the old sheath, which 

 eventually became completely detached from the core by the breaking and tearing 

 away of the hairs passing from the skin into its substance. When nearly the whole 

 of the hairs were detached or broken, any sudden motion of the animal would 

 doubtless lead to the loss of the horns; but it does not appear that, at least as a 

 rule, the process is assisted by the animal rubbing its horns against neighboring 

 objects. In regard to the renovating process, Mr. Caton writes that " when the old 

 horn was cast off, the new one, as we have already seen, had made a considerable 

 growth above the core, which was already tipped with perfected horn, while a sec- 



