modified have been transmitted to her alone. It is, however, probable
that some of the many successive variations would have been transmitted
to, and developed in, the males had not such males been eliminated by
being thus rendered less attractive to the females; so that only those
variations were preserved which were from the first strictly limited in
their transmission to the female sex. We have a partial illustration of
these remarks in a statement by Mr. Belt (32. The Naturalist in
Nicaragua, 1874, p. 385.); that the males of some of the Leptalides,
which imitate protected species, still retain in a concealed manner
some of their original characters. Thus in the males the upper half of
the lower wing is of a pure white, whilst all the rest of the wings is
barred and spotted with black, red and yellow, like the species they
mimic. The females have not this white patch, and the males usually
conceal it by covering it with the upper wing, so that I cannot imagine
its being of any other use to them than as an attraction in courtship,
when they exhibit it to the females, and thus gratify their deep-seated
preference for the normal colour of the Order to which the Leptalides
belong.
BRIGHT COLOURS OF CATERPILLARS.
Whilst reflecting on the beauty of many butterflies, it occurred to me
that some caterpillars were splendidly coloured; and as sexual
selection could not possibly have here acted, it appeared rash to
attribute the beauty of the mature insect to this agency, unless the
bright colours of their larvae could be somehow explained. In the first
place, it may be observed that the colours of caterpillars do not stand
in any close correlation with those of the mature insect. Secondly,
their bright colours do not serve in any ordinary manner as a
protection. Mr. Bates informs me, as an instance of this, that the most
conspicuous caterpillar which he ever beheld (that of a Sphinx) lived
on the large green leaves of a tree on the open llanos of South
America; it was about four inches in length, transversely banded with
black and yellow, and with its head, legs, and tail of a bright red.
Hence it caught the eye of any one who passed by, even at the distance
of many yards, and no doubt that of every passing bird.
I then applied to Mr. Wallace, who has an innate genius for solving
difficulties. After some consideration he replied: Most caterpillars
require protection, as may be inferred from some kinds being furnished
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