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SEXUAL selection: mammals. 
Part IL- 
strengthen those in the upper jaw, from being ground 
so as to fit closely against 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-hog is 
not 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 the living animal, that these pads, when struck from 
beneath 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 authority of Mr. Bartlett, when fighting 
together, stand directly face to face. 
Lastly, the African river-hog (Potamochoerus penicil- 
latus) has a hard cartilaginous knob on each side of 
the 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 
informs me, engage in terrible battles, and a young 
lion dares not approach an old one. In 1857 a tiger 
at Bromwich broke into the cage of a lion, and a 
