Chap. XVIL] 



MEANS OF DEFENCE. 



251 



offspring alone ; and thus the great inequality in size be- 

 tween the sexes of the Scotch deer-hound may probably 

 be accounted for. 



The males of some few quadrupeds possess organs or 

 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 ex- 

 clusively for defending themselves ; and the Oryx ante- 

 lope, as I am informed by Mr. Bartlett, fences most skil- 

 fully with his long, gently-curved horns ; but these are 

 likewise used as organs of offence. Rhinoceroses, as the 

 same observer remarks, in fighting parry each other's side- 

 long blows with their horns, which loudly clatter together, 

 as do the tusks of 

 boars. Although wild- 

 boars fight desperate- 

 ly together, they sel- 

 dom, according to 

 Brehm, receive fatal 

 blows, as these fall on 

 each other's tusks, or 

 on the layer of gristly 

 skin covering the shoul- 

 der, which the German 

 hunters call the shield ; 

 and here we have a 

 part specially 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 inward and upward, 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 com- 

 pensation for the loss of the lower tusks as weapons of 

 offence, those in the upper jaw, which always project a 



Fte^e:^ 



Fig. 63.— Head of common-wild hoar, in 

 prime of life (from Brehm). 



