Chap. XVII. 
MEANS OF DEFENCE. 
263 
parts developed solely as a means of defence against 
the attacks of other males. Some kinds of deer use, 
as we have seen, the upper branches of their horns 
chiefly or exclusively for defending themselves ; and 
the Oryx antelope, as I am informed by Mr. Bartlett, 
fences most skilfully with his long, gently curved horns ; 
but these are likewise used as organs of offence. Ehi- 
noceroses, as the same observer remarks, in fighting 
parry each other’s sidelong blows with their horns, 
which loudly clatter together, as do the tusks of boars. 
Although wild boars fight desperately together, they 
seldom, according to Brehm, receive fatal blows, as 
these fall on each other’s tusks, or on the layer of 
gristly skin covering the shoulder, which the German 
hunters call the shield ; and here we have a part speci- 
ally modified for defence. With boars in the prime 
of life (see fig. 63) 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 
thus used. They may, 
however, still continue 
to serve, and even in 
a still more effective 
manner, 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 later- 
ally, increase so much in length during old age, and 
curve so much upwards, that they can be used as a 
means of attack. Nevertheless an old boar is not so 
Fig. 63. Head of common wild boar, in prime 
of life (from Brehm). 
