266 SEXUAL SELECTION : MAMMALS. Part II, 



strengthen those in the upper jaw, from being ground 

 so as to fit closely ao-ainst their bases. Neither the 

 upper nor the lower tusks appear to have been speci- 

 ally modified to act as guards, though, no doubt, they 

 are thus used to a certain extent. But the wart-boo* is 

 iiot destitute of other special means of protection, for 

 there exists, on each side of the face, beneath the eyes, 

 a rather stiff, yet flexible, cartilaginous, oblong pad 

 (fig. 65), which projects two or three inches outwards ; 

 and it appeared to Mr. Bartlett and myself, when view- 

 ing tlie living animal, that these pads, when struck from 

 baneath by the tusks of an opponent, would be turned 

 upwards, and would thus protect in an admirable man- 

 ner the somewhat prominent eyes. These boars, as I 

 may add on the avithority of Mr. Bartlett, when fighting 

 together, stand directly face to face. 



Lastly, the African river-hog (PotamocJioerus jpenicil- 

 latus) has a hard cartilaginous knob on each side of 

 tlie face beneath the eyes, which answers to the flexible 

 pad of the wart-hog ; it has also two bony prominences 

 on the upper jaw above the nostrils. A boar of this 

 species in the Zoological Gardens recently broke into 

 the cage of the wart-hog. They fought all night-long, 

 and were found in the morning much exhausted, but 

 not seriously wounded. It is a significant fact, as 

 shewing the purpose of the above-described projections 

 and excrescences, that these were covered with blood, 

 and were scored and abraded in an extraordinary 

 manner. 



The mane of the lion forms a good defence against 

 the one danger to which he is liable, namely the at- 

 tacks of rival lions : for the males, as Sir. A. Smith 

 infoims me, eni2,-aoe in terrible battles, and a vounof 

 lion dares not approach an old one. In 1857 a tiger 

 at Bromwich broke into the cage of a lion, and a 



