XI ANATOMY OF PIGS 25 
ean and does attack and destroy human beings. The Hippo- 
potamus not only swims, but can walk along the bottom of a 
river with great rapidity. It occasionally puts out to sea from 
the mouths of rivers frequented by it; and it is supposed that in 
this way Madagascar was populated with Hippopotamuses, whose 
remains are now found in swamps in that island. 
Fam. 2. Suidae.— The Pig family, Suidae, differ from the last 
in their smaller size, in the terminal nostrils and mobile snout, 
which is not grooved, except faintly as in Babirusa. They are 
generally hairy, but the Babyroussa is an exception, while Phaco- 
Fria. 141.—Wild Boar. Sus scrofa. x 4s. 
choerus is but slightly haired. Though there are four digits, as 
in the Hippopotamus, only two reach the ground in walking. 
The stomach, furthermore, is simple, and (except in Dicotyles) there 
is a caecum. The kidneys are smooth, and the liver is more 
lobate than in Hippopotamus. The orbital cavity is confluent 
with the temporal fossa. The typical genus, Sus, is distributed 
over Europe, Asia, and the islands of the Malay Archipelago, 
reaching as far as Borneo and Celebes. The dentition! is 
complete. -A single species, the so-called S. sennaariensis, is 
from Ethiopian Africa, but it is not certain how far this animal 
may be an escaped species introduced by man. <A very large 
number of “species” of Sus have been described, but Dr. Forsyth 
1 There is, however, some doubt about the first premolars. 
