PIGS. 
425 
naked surface at the extremity, in which are situated the nostrils, the disc being 
supported by an additional separate bone at the extremity of the skull, as shown 
in our figure. The feet are narrow, and carry four completely-developed toes, 
of which the hindmost do not touch the ground in walking, while the inner 
surfaces of the main pair are flattened. The molar teeth are narrow, the last 
one in both the upper and lower jaw being more or 
less elongated; and the large tusks grow continuously 
throughout life, those of the upper jaw curving up¬ 
wards, instead of pointing downwards, after the usual 
fashion. Swine have large flapping ears, and rather 
long cylindrical tails, with a tuft at the end. Their 
bodies are more or less sparsely clothed with bristly 
hairs, and their stomachs are quite simple. Like all 
unspecialised Ungulates, swine have the neck short and thick, and imperfectly 
differentiated both from the body and the head, the latter being consequently 
carried low. The whole of the existing members of the family are restricted to 
the Old World; and they chiefly frequent damp or swampy districts, and are fond 
of wallowing in wet mud. 
THE LAST RIGHT LOWER MOLAR 
TOOTH OF A PIG. 
The True Pigs. 
Genus Sus. 
The typical representatives of the Pig family, such as the European wild 
boar, are characterised by having forty-four teeth, among which the last molar in 
each jaw is greatly elongated, while the thick and short upper tusk is turned 
sharply upwards, and has a large smooth facet worn on the outer side of its 
upturned extremity by the abrasion of the inner surface of the extremity of the 
lower tusk. Consequently, if either tusk happens to be broken, the opposing 
one continues to grow indefinitely, and, from its curved form, generally pierces 
some portion of the skull with its tip, thus ultimately leading to the death of 
the animal which has had the misfortune to meet with an accident of this nature. 
In addition to the bristly hairs, there is generally a more or less developed woolly 
under-fur. The skull of the pigs, besides the presence of the additional bone in 
the snout already mentioned, is remarkable for the great length of the nasal 
bones, and also for the high elevation of the crest of the occiput, which is generally 
even more developed than in the specimen figured here. In wild pigs the profile 
of the face is straight, although in most domesticated races it is more or less 
concave. Pigs are exceedingly prolific animals; and the young of all the wild 
species (as shown in our illustration) are marked with light longitudinal stripes, 
although these markings are very rarely observed in those of domesticated 
breeds. 
Distribution. 
The distributional area of the genus, before curtailed by human 
agency, was extensive, comprising the greater part of Europe, 
Southern, and a portion of Central, Asia, Japan, the islands of the Malayan 
region, and Africa. The two species inhabiting Africa south of the Sahara 
