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 parelehta 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 by 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 sufficiently 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 chrysalides of 
butterflies possess a most astonishing means of eluding 
340 
