a small beetle
(Chlamys pilula) which was undistinguishable by the eye from the dung of
caterpillars, while some of the Cassidae, from their hemispherical forms
and pearly gold colour, resemble glittering dew-drops upon the leaves.

A number of our small brown and speckled weevils at the approach of any
object roll off the leaf they are sitting on, at the same time drawing
in their legs and antennae, which fit so perfectly into cavities for
their reception that the insect becomes a mere oval brownish lump, which
it is hopeless to look for among the similarly coloured little stones
and earth pellets among which it lies motionless.

The distribution of colour in butterflies and moths respectively is very
instructive from this point of view. The former have all their brilliant
colouring on the upper surface of all four wings, while the under
surface is almost always soberly coloured, and often very dark and
obscure. The moths on the contrary have generally their chief colour on
the hind wings only, the upper wings being of dull, sombre, and often
imitative tints, and these generally conceal the hind wings when the
insects are in repose. This arrangement of the colours is therefore
eminently protective, because the butterfly always rests with his wings
raised so as to conceal the dangerous brilliancy of his upper surface.
It is probable that if we watched their habits sufficiently we should
find the under surface of the wings of butterflies very frequently
imitative and protective. Mr. T. W. Wood has pointed out that the little
orange-tip butterfly often rests in the evening on the green and white
flower heads of an umbelliferous plant, and that when observed in this
position the beautiful green and white mottling of the under surface
completely assimilates with the flower heads and renders the creature
very difficult to be seen. It is probable that the rich dark colouring
of the under side of our peacock, tortoiseshell, and red-admiral
butterflies answers a similar purpose.

Two curious South American butterflies that always settle on the trunks
of trees (Gynecia dirce and Callizona acesta) have the under surface
curiously striped and mottled, and when viewed obliquely must closely
assimilate with the appearance of the furrowed bark of many kinds of
trees. But the most wonderful and undoubted case of protective
resemblance in a butterfly which I have ever seen, is that of the common
Indian Kallima inachis, and its Malay