the upper surface of his wings, rests with them closed; and this shows
that the blue colour cannot be in any way protective. Nevertheless, it
is probable that conspicuous colours are indirectly beneficial to many
species, as a warning that they are unpalatable. For in certain other
cases, beauty has been gained through the imitation of other beautiful
species, which inhabit the same district and enjoy an immunity from
attack by being in some way offensive to their enemies; but then we
have to account for the beauty of the imitated species.
As Mr. Walsh has remarked to me, the females of our orange-tip
butterfly, above referred to, and of an American species (Anth.
genutia) probably shew us the primordial colours of the parent-species
of the genus; for both sexes of four or five widely-distributed species
are coloured in nearly the same manner. As in several previous cases,
we may here infer that it is the males of Anth. cardamines and genutia
which have departed from the usual type of the genus. In the Anth. sara
from California, the orange-tips to the wings have been partially
developed in the female; but they are paler than in the male, and
slightly different in some other respects. In an allied Indian form,
the Iphias glaucippe, the orange-tips are fully developed in both
sexes. In this Iphias, as pointed out to me by Mr. A. Butler, the under
surface of the wings marvellously resembles a pale-coloured leaf; and
in our English orange-tip, the under surface resembles the flower-head
of the wild parsley, on which the butterfly often rests at night. (10.
See the interesting observations by T.W. Wood, The Student, Sept.
1868, p. 81.) The same reason which compels us to believe that the
lower surfaces have here been coloured for the sake of protection,
leads us to deny that the wings have been tipped with bright orange for
the same purpose, especially when this character is confined to the
males.
Most Moths rest motionless during the whole or greater part of the day
with their wings depressed; and the whole upper surface is often shaded
and coloured in an admirable manner, as Mr. Wallace has remarked, for
escaping detection. The front-wings of the Bombycidae and Noctuidae
(11. Mr. Wallace in Hardwicke s Science Gossip, September 1867, p.
193.), when at rest, generally overlap and conceal the hind-wings; so
that the latter might be brightly coloured without much risk; and they
are in fact often thus coloured. During flight, moths would often be
able to escape from their enemies; nevertheless, as the hind-wings are
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