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ANIMAL DEFENCES 



creatures voluntarily convert the surfaces of their bodies into a 

 kind of sea- weed garden. " The Crab takes a piece of weed in 

 his two chelae, and, neither snatching nor biting it, deliberately 

 tears it across, as a man tears paper with his hands. He then 



Fig. 478. Upper side of a Xenophorus Shell 



puts one end of it into his mouth, and after chewing it up, pre- 

 sumably to soften it, takes it out in the chelae and rubs it firmly 

 on his head or legs until it is caught by the peculiar curved hairs 

 which cover them. If the piece of weed is not caught by the 

 hairs, the Crab puts it back in his mouth and chews it up again. 

 The whole proceeding is most human and purposeful. Many 

 substances, as hydroids, sponges, Polyzoa, and weeds of many 

 kinds and colours, are thus used, but these various substances 



