ORIGIN OF DOMESTICATED ANIMALS 233 
about the size of a common mule down to one not much larger 
than the modern pigmy hog of India. Evidently the hog tribe 
has been a long time with us and has seen, as it is now seeing, 
exceedingly prosperous days. 
Besides these already mentioned, Asia affords another notable 
species, the babiroussa, a little further removed from the true 
pig, as he has a pair of tusks rising from his nose and midway 
between his snout and his eyes. He is, however, essentially a 
wild pig, and in his natural habitat, the lowlands of Celebes, he 
is found both wild and domesticated. 
Africa affords a goodly number of wild relatives, notably the 
gray bush pig (Sus africanus) of the south-central regions and 
the little red bush pig or river hog (Sus porcus) of the west- 
ern lowlands. Aside from these true pigs there are several 
species of the so-called wart hogs, ugly specimens with immense 
heads and broad noses crowned with vicious tusks, deriving 
their name from three hornlike “warts” that develop on the 
side of the face just below the eyes. 
Altogether the pig is not at all wanting in relatives of the 
woods, even without going to the more remote connections such 
as the rhinoceros, the hippopotamus, or the elephant. Of all our 
domesticated animals none are more readily traced to the wild and 
none more quickly or more thoroughly revert to the feral state. 
The pig in domestication is generally quiet and harmless, but he 
is capable of a good fight, and in the semiwild state a drove of 
hogs is an enemy more dangerous than most wild animals. 
Quite contrary to popular opinion, the pig is among the 
cleanest of our domestic animals. Like the buffalo he seeks 
the water, or mud in absence of water, as a protection against 
the heat of the sun. Having no sweat glands, he gets no relief 
by evaporation from his own body, and his resort to the cooling 
effects of water is not only natural but necessary. 
The cat (Felis catus). Here again domestication is lost in 
antiquity, but the origin is not difficult to trace. Wild catlike 
animals are common in the world, and nowhere more common 
