horns than teeth, and are so manifestly useless as teeth that the
animal was formerly supposed to rest his head by hooking them on to a
branch! Their convex surfaces, however, if the head were held a little
laterally, would serve as an excellent guard; and hence, perhaps, it is
that in old animals they are generally broken off, as if by fighting.
(40. See Mr. Wallace s interesting account of this animal, The Malay
Archipelago, 1869, vol. i. p. 435.) Here, then, we have the curious
case of the upper tusks of the Babirusa regularly assuming during the
prime of life a structure which apparently renders them fitted only for
defence; whilst in the European boar the lower tusks assume in a less
degree and only during old age nearly the same form, and then serve in
like manner solely for defence.
[Fig. 67. Head of female Aethiopian wart-hog, from Proc. Zool. Soc.
1869, shewing the same characters as the male, though on a reduced
scale. N.B. When the engraving was first made, I was under the
impression that it represented the male.]
In the wart-hog (see Phacochoerus aethiopicus, Fig. 67) the tusks in
the upper jaw of the male curve upwards during the prime of life, and
from being pointed serve as formidable weapons. The tusks in the lower
jaw are sharper than those in the upper, but from their shortness it
seems hardly possible that they can be used as weapons of attack. They
must, however, greatly strengthen those in the upper jaw, from being
ground so as to fit closely against their bases. Neither the upper nor
the lower tusks appear to have been specially modified to act as
guards, though no doubt they are to a certain extent used for this
purpose. But the wart-hog is not destitute of other special means of
protection, for it has, on each side of the face, beneath the eyes, a
rather stiff, yet flexible, cartilaginous, oblong pad (Fig. 67), which
projects two or three inches outwards; and it appeared to Mr. Bartlett
and myself, when viewing the living animal, that these pads, when
struck from beneath by the tusks of an opponent, would be turned
upwards, and would thus admirably protect the somewhat prominent eyes.
I may add, on the authority of Mr. Bartlett, that these boars when
fighting stand directly face to face.
Lastly, the African river-hog (Potomochoerus penicillatus) has a hard
cartilaginous knob on each side of the face beneath the eyes, which
answers to the flexible pad of the wart-hog; it has also two bony
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