The Descent of Man

the German hunters, the shield; and here we
have a part specially modified for defence.
With boars in the prime of life (Fig. 65) the
tusks in the lower jaw are used for fighting, but
they become in old age, as Brehm states, so
much curved inwards and upwards over the
snout that they can no longer be used in this
way. They may, however, still serve, and even
more effectively, as a means of defence. In
compensation for the loss of the lower tusks as
weapons of offence, those in the upper jaw,
which always project a little laterally, increase
in old age so much in length and curve so
much upwards that they can be used for attack.
Nevertheless, an old boar is not so dangerous
to man as one at the age of six or seven years.
(39. Brehm, 'Thierleben,' B. ii. ss. 729-732.)
[Fig. 66. Skull of the Babirusa Pig (from Wallace's
'Malay Archipelago').]
In the full-grown male Babirusa pig of Celebes
(Fig. 66), the lower tusks are formidable wea-