52 MR. OGILBY'S MONOGRAPH 



along with it consequences of greater moment than the mere texture of the horn. In 

 the former class the young horn is covered with a vascular skin whicli supplies it with 

 nutriment, and the growth goes on simultaneously and without interruption, from the 

 upper extremity, till the organ is completed ; the vessels then dry up, the skin exfoliates, 

 and leaves the surface of the horn smooth, or marked with minute pearly granulations, 

 and nearly of the same thickness throughout. In the latter the horns receive their in- 

 crements at the lower extremity ; they continue to grow throughout life, but only at 

 intervals, depending upon the season of the year, the age of the individual, and the 

 supply of food. The outer surface is consequently marked in general with a greater or 

 less number of prominent transverse rings or annuli, more or less contiguous, numerous, 

 and projecting, according to the age, sex and species of the animal, and occasioned by the 

 interruption which the growth of the horn suffers at particular seasons, and the super- 

 abundance of nutritious matter supplied to it at others. The number of these annuli 

 depends upon two circumstances, the species of the animal and the age of the individual. 

 In the adult Addax and Leucoryx they amount to between thirty and forty ; whilst in the 

 Madoqua and Duikerhok they seldom exceed three or four. In some species they are 

 scarcely perceptible, whilst in others they form prominent knobs ; some have them com- 

 pletely surrounding the horn, others only in front ; in some the interstices are beauti- 

 fullv marked with longitudinal striae, in others plain ; but in all cases the rings are most 

 distant towards the points of the horns, and more nearly approximated as they approach 

 the base. The terminal quarter at least is usually smooth and pointed, and as this part 

 is the earliest developed, it follows that all young animals have the horns of this smooth 

 polished character : it is only when they arrive at maturity, and are fit for propagation, 

 that the horns begin to exhibit annuli, but the number of these added in a given time 

 appears to be very variable. The common Coiv is generally supposed to acquire one 

 ring on the horn every year after the third, but this is far from being a general law. 

 Between the 20th of July and the 31st of October 1833, the horns of a young Indian 

 Antelope {A. cervicapra), which I had marked for the purpose, in the gardens of the 

 Society, acquired an addition of no fewer than three rings, and an increase in length of 

 a full inch and a half; and I have observed a similar phgenomenon in other species. 



2. The permanent or deciduous character of the horns depends on their hoUowness or 

 solidity. Hollow horns are usually considered synonymous with permanent, but this is 

 not strictly correct ; solid are for the most part deciduous, and that in general annually. 

 According to Sir T. S. Raffles', the Muntjacs seldom shed their horns, and the opinion 

 is countenanced by my own observation of different specimens in the Society's gardens. 

 An individual formerly presented by Colonel Sykes shed one of its horns early in 1832, 

 and had not completely renewed it in the autumn of the following year ; the other horn 

 was never shed, though the animal throve well and always enjoyed good health. Colonel 



' Linn. Tran3., xiii. 265. 



