THE BO VINES 345 



gnu, the resemblance, of course, being purely accidental. The 

 flattened base of the horns and a good deal of their length is in 

 adult males marked by coarse, broken grooves o^fissures running 

 parallel with the length of the horn. In some specimens of 

 younger animals or females these longitudinal fissures are less 

 marked, and are crossed at right angles by " ripplings," which 

 may be the traces of original annulations similar to those which 

 characterise the horns of antelopes, sheep, and capricorns. Much 

 of the extravagant boss represented in the frontal portion of the 

 male's horn is but a development of the outer horny sheath, and 

 is only represented by a very roughened surface of bone, from 

 which the horn core grows out sideways. In the female the 

 horny coverings of these bosses do not meet in the centre, but 

 there is a considerable space between the horn bosses covered 

 with hair. In the young animal (and this is a characteristic of 

 the horns of fossil American species) the shape and direction 

 of the horns are not so aberrant. The bony core grows 

 out laterally and horizontally from the frontal bone, as it 

 does in the common ox, and the horny sheath continues this 

 horizontal direction, and then turns sharply upward exactly like 

 the horns of a domestic cow. There is at this stage (and the 

 same remark applies to at least one species of fossil musk ox) no 

 downward sweep of the horn. We are still, however, very far 

 from the type of horn found in the capricorns (excepting 

 'Budorcas), for in these the bony cores and their horny coverings 

 rise more or less vertically from the frontal bone, and are directed 

 backwards. This is the same with sheep and goats, except that 

 in the former, after an upward and backward direction, the horns 

 curve round in most cases to the front. In the North African 

 wild sheep, however, there is some approximation made to the 

 outward and downward curve of the musk ox's horns. 



The female musk ox has a somewhat primitive udder. There 

 are four functional teats, and an extra, or fifth mamma, which is 

 not functional. This feature of five teats is repeated (not 

 functionally, of course) in the male. In the True Oxen, besides 

 the four functional teats of the udder, there are (as any one can 



