Wild Boar, are compressed laterally with an elliptic transverse
section, and a smooth unenamelled exterior. Their socket seems
as if it had been pulled out or produced from the alveolar border
of the upper maxillary bone, and then bent abruptly upwards, giving
the tusk a direction upwards and backwards. The tooth pierces
the integuments of the upper lip, like a horn, and its growth,
being unchecked by any opposing tooth, sometimes forces the
tip again through the integument and into the substance of the
skull. The lower tusks have the ordinary direction, but rise rather
more vertically and much higher than in the Wild Boar ; they are
suhtrihedral with rounded angles, except the inner one towards the
point, and sometimes show upon their inner side slight marks of
abrasion against the outer side of the base of the upper tusks.
These tusks are well adapted by their position to defend the eyes,
and assist in the act of forcing the head through the dense entangled
under-wood of a tropical forest, as suggested in Home’s
Comparative Anatomy (Vol. x, p. 221); but their use has not
been determined by actual observation : speculation, however, has
not been idle in assigning final purposes to these singularly
developed teeth, which are too absurd for repetition. The molar
series is speedily reduced in the Babiroussa to two premolars and
three true molars on each side of both jaws : the great activity
of the vascular matrix of the long tusks soon exhausts the
conservative force of those of the adjoining small premolars. The
upper molars much resemble those of the Hog, but are relatively
narrower; the four principal tubercles are better marked on the
penultimate and last true molars, and the accessory tubercular
talon of the latter is relatively smaller. In the lower jaw, also,
the third lobe of the last molar is smaller, and the four principal
tubercles constitute a more conspicuous and important part of the
crown. (1)
(1) A fossil under jaw has been described and figured in Silliman’s American Journal
of Science, Vol. xliii. 1842, PI. 3. fig. 1, under the name of Sus Americana, by Dr. Harlan,
who conceived that from “ its general appearance and number of the teeth this fragment
bore a close analogy with the same part in the Sus bdbirussa, Buff., although the Babiroussa
was a much smaller animal.” Having compared a cast of this fossiljaw, I find that, besides
the difference of size, there is a difference in the proportions of the true molar teeth, the
197. PJiacochærus.iV).—The rate of increase of size from the first
to the third true molar (PI. 14], fig. 2) is carried to its maximum in
the Phacochères or Wart Hogs of Africa, and the folds of the capsule
producing the multicuspid grinding surface here attain a depth,
number, cylindrical figure, and regularity of arrangement, which
produce so peculiar a modification of the structure of the molar
teeth, as, with other and minor differences, to justify the subgeneric
separation of those large and formidable Hogs from the
rest of the Suida. (2)
The Wart Hog of Nubia, Abyssinia and Kordofan (Phaco-
chærus Æliana, Rüppell) (3) has the incisors reduced to, two in the
upper jaw, corresponding with the median pair in other Hogs ; a
single short, thick, and inwardly curved incisor being inserted near
the end of each intermaxillary bone : the margin of the unworn
crown of this incisor in the young animal is divided into three
equal tubercles by two notches, which are soon obliterated : they
are larger in the males than in the females, according to Rüppell,
(loc. cit. p. 62). The upper tusks are longer and larger than
the lower ones and curve outwards, upwards and backwards : they
first being two-thirds the size of the last, whilst in the Babiroussa it is less than half.
The last molar in the fossil has the anterior transverse ridge proportionally larger and the
posterior lobe proportionally smaller than in the Babiroussa, resembling the Lophiodon in
the points in which it thus differs from the Sus cited. The form of the jaw differs at this
part of the fossil from that in the Babiroussa, in which the socket of the last molar overhangs
the inner surface of the, ramus, whilst in the fossil the inner surface of the ramus
beneath the last molar describes a gentle convexity from the tooth to the lower margin.
The outer part of the ramus of the jaw of the Babiroussa begins to expand below the
fourth and fifth molars, counting forwards from the last, to form the socket of the large
tusk, but the fossil jaw does not offer the least indication of an enlargement for that
purpose, and the fractured anterior end, as displayed in the cast, is very different in
shape from the corresponding part of the jaw in the Babiroussa, and shows merely the
dental canal and no socket for the tusk which would be here situated in the Babiroussa
or Wild Boar. The nearest approximation which the fossil in question allows to be made
to any known existing or extinct animal is to the great tapiroid Pachyderms.
(1) fàxàc a Wart, %oipos a Hog.
(2) M. F. Cuvier says, “ Nous voici arrives à un système de dentition tout-à-fait
différent de celui des sangliers.” Dents de Mammifères, p. 213; but this is rather too
strong an expression.
(3) ‘Atlas zu der Reise im Nördlichen Afrika,’ fol. 1826, Erste Abth. p. 61, fig. 25
& 26. The ‘Sanglier du Cap Verd.’ of ‘Buffon,’ (t. xiv., p. 409), is of this species.