MAMMALS— MEANS OF DEFENSE. 



515 



are so manifestly useless as teeth, that the animal was formerly- 

 supposed to rest his head by hooking them on to a branch! 

 Their convex surfaces, however, if the head were held a little 

 laterally, would serve as an excellent guard; and hence, perhaps, 

 it is that in old animals they "are generally broken off, as if by 

 "fighting."" Here, then, we have the curious case of the upper 

 tusks of the Babirusa regularly assuming during the prime of 

 life, a structure which apparently renders them fitted only for 

 defense; whilst in the European boar the lower tusks assume in 

 a less degree and only during old age, nearly the same form, and 

 then serve in like manner solely for defense. 









Fig. 67. Head of female Ethiopian wart-hog, from 'Proo. Zool. Soc' 

 1S69, showing the same characters as the male, though on a re- 

 duced scale. 



N. B. When the engraving was first made, I was under the impression 

 that it represented the male. 



In the wart-hog (Phacochoerus sethiopicus, fig. 67) the tusks in 

 the upper jaw of the male curve upwards during the prime of 

 life and from being pointed serve as formidable weapons. The 

 tusks in the lower jaw are sharper than those in the upper, but 

 from their shortness it seems hardly possible that they can be 

 used as weapons of attack. They must, however, greatly strength- 

 en those in the upper jaw, from being ground so as to fit closely 

 against their bases. Neither the upper nor the lower tusks ap- 

 pear to have been specially modified to act as guards, though 

 no doubt they are to a certain extent used for this purpose. 



" See Mr. Wallace's interesting account of this animal, 'The Malay 

 Archipelago,' 1869, vol. i. p. 435. 



