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The Descent of Man

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ce <strong>of</strong> tusks in some female walruses—are all<br />

instances <strong>of</strong> the extreme variability <strong>of</strong> secondary<br />

sexual characters, and <strong>of</strong> their liability to<br />

differ in closely-allied forms.<br />

Although tusks and horns appear in all cases to<br />

have been primarily developed as sexual weapons,<br />

they <strong>of</strong>ten serve other purposes. <strong>The</strong><br />

elephant uses his tusks in attacking the tiger;<br />

according to Bruce, he scores the trunks <strong>of</strong> trees<br />

until they can be thrown down easily, and he<br />

likewise thus extracts the farinaceous cores <strong>of</strong><br />

palms; in Africa he <strong>of</strong>ten uses one tusk, always<br />

the same, to probe the ground and thus ascertain<br />

whether it will bear his weight. <strong>The</strong> common<br />

bull defends the herd with his horns; and<br />

the elk in Sweden has been known, according<br />

to Lloyd, to strike a wolf dead with a single<br />

blow <strong>of</strong> his great horns. <strong>Man</strong>y similar facts<br />

could be given. One <strong>of</strong> the most curious secondary<br />

uses to which the horns <strong>of</strong> an animal may<br />

be occasionally put is that observed by Captain

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