Introduction XVil 
ticular object is copied in shape and outline as well as in 
colour. Numerous instances will be found in this book, 
and a ‘“‘ Leaf Insect ”’ and a “‘ Moss Insect ”’ are illustrated 
on pages 292 and 293. But the classic example is the 
butterfly from the East Indies so graphically described by 
Mr. Wallace, Kallima paralekia, which always rests among 
dead or dry leaves and has itself leaf-like wings spotted 
over with specks to imitate the tiny fungi growths on the 
foliage it resembles. ‘“‘It sits on a nearly upright twig, 
the wings fitting closely back to back, concealing the 
antenne and head, which are drawn up between their bases. 
The little tails of the hind wings 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 
inconspicuous. The irregular outline of the wings gives 
exactly the perspective effect of a shrivelled leaf.” The 
wonderful “‘ stick insects ”’ in like manner mimic the twigs 
of the trees among which they lurk. Nor need we go 
abroad in search of examples, for among our own insects 
are countless instances of marvellous resemblances to the 
inanimate or vegetable objects upon which they rest. One 
of the most interesting is that of the geometer caterpillars, 
which are very plentiful, and any one can observe them for 
himself even in a London garden. They support them- 
selves for hours by means of their posterior legs, forming 
an angle of various degrees with the branch on which they 
are standing and looking for all the world like one of its 
twigs. The long cylindrical body is kept stiff and im- 
movable, with the separations of the segments scarcely 
visible, and its colour is obscure and similar to that of the 
bark of the tree. Kirby and Spence tell of a gardener 
mistaking one of these caterpillars for a dead twig, and 
starting back in great alarm when, on attempting to break 
it off, he found it was a living animal. 
Sometimes concealment is secured by the aid of adven- 
titious objects. Many lepidopterous larve live in cases 
made of the fragments of the substances upon which they 
feed; and certain sea-urchins cover themselves so com- 
pletely with pebbles, shells, and so forth, that one can see 
nothing but a heap of little stones. Perhaps, however, the 
most interesting instance is the crab described by Mr. 
Bateson, which ‘‘ takes a piece of weed in his two chelz 
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