WILD ANIMALS IN CAPTIVITY 



contributions to the Theory of Natural Selection may be 

 taken as a good illustration of this part of the subject. 

 At p. 61 he says : — " I myself had the good fortune to 

 observe scores of Kallima parelelda in Sumatra, and to 

 capture many of them, and can vouch for the accuracy of 

 the following details : — These butterflies frequent dry 

 forests, and fly very swiftly. They were never seen to 

 settle on a flower or a green leaf, but were many times lost 

 sight of in a bush or tree of dead leaves. On such oc- 

 casions they were generally searched for in vain, for while 

 gazing intently at the very spot where one had disappeared, 

 it would often suddenly dart out, and again vanish twenty 

 or fifty yards further on. On one or two occasions the 

 insect was detected reposing, and it could then be seen 

 how completely it assimilates itself to the surrounding 

 leaves. It sits on a nearly upright twig, the wings fitting 

 closely back to back, concealing the antennae and head, 

 which are drawn up between their bases. The little tails 

 of the hind wing touch the branch and form a perfect 

 stalk to the leaf, which is supported in its place hy the 

 claws of the middle pair of feet, which are slender and in- 

 conspicuous. The irregular outline of the wings gives 

 exactly the perspective effect of a shrivelled leaf. We 

 thus have size, colour, form, markings, and habits, all 

 combining together to produce a disguise which may be 

 said to be absolutely perfect ; and the protection which it 

 affords is sufiiciently indicated by the abundance of the 

 individuals that possess it." 



Another careful and trustworthy observer of nature, and 

 one who, as an artist, lent his valuable aid by the very 

 faithful representations published in the Student, Sep- 

 tember 1868, illustrating his observations upon "Insects 

 in Disguise," remarks at p. 83 : — " The chiysalides of 

 butterflies possess a most astonishing means of eluding 



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