er fantastic flower. The whole insect
is of a bright pink colour, the large and oval abdomen looking like the
labellum of an orchid. On each side, the two posterior legs have
immensely dilated and flattened thighs which represent the petals of a
flower, while the neck and forelegs imitate the upper sepal and column
of an orchid. The insect rests motionless, in this symmetrical attitude,
among bright green foliage, being of course very conspicuous, but so
exactly resembling a flower that butterflies and other insects settle
upon it and are instantly captured. It is a living trap, baited in the
most alluring manner to catch the unwary flower-haunting insects.[80]

_The Coloration of Birds' Eggs._

The colours of birds' eggs have long been a difficulty on the theory of
adaptive coloration, because, in so many cases it has not been easy to
see what can be the use of the particular colours, which are often so
bright and conspicuous that they seem intended to attract attention
rather than to be concealed. A more careful consideration of the subject
in all its bearings shows, however, that here too, in a great number of
cases, we have examples of protective coloration. When, therefore, we
cannot see the meaning of the colour, we may suppose that it has been
protective in some ancestral form, and, not being hurtful, has persisted
under changed conditions which rendered the protection needless.

We may divide all eggs, for our present purpose, into two great
divisions; those which are white or nearly so, and those which are
distinctly coloured or spotted. Egg-shells being composed mainly of
carbonate of lime, we may assume that the primitive colour of birds'
eggs was white, a colour that prevails now among the other egg-bearing
vertebrates--lizards, crocodiles, turtles, and snakes; and we might,
therefore, expect that this colour would continue where its presence had
no disadvantages. Now, as a matter of fact, we find that in all the
groups of birds which lay their eggs in concealed places, whether in
holes of trees or in the ground, or in domed or covered nests, the eggs
are either pure white or of very pale uniform coloration. Such is the
case with kingfishers, bee-eaters, penguins, and puffins, which nest in
holes in the ground; with the great parrot family, the woodpeckers, the
rollers, hoopoes, trogons, owls, and some others, which build in holes
in trees or other concealed places; while martins, wrens,
willow-warblers,