tted over with lines and groups of scales of a clear
ashy blue. Its wings are five inches in expanse, and the hind wings
are rounded, with scalloped edges. This applies to the males; but
the females are very different, and vary so much that they were once
supposed to form several distinct species. They may be divided into two
groups--those which resemble the male in shape, and, those which differ
entirely from him in the outline of the wings. The first vary much in
colour, being often nearly white with dusky yellow and red markings, but
such differences often occur in butterflies. The second group are much
more extraordinary, and would never be supposed to be the same insect,
since the hind wings are lengthened out into large spoon-shaped tails,
no rudiment of which is ever to be perceived in the males or in the
ordinary form of females. These tailed females are never of the dark
and blue-glossed tints which prevail in the male and often occur in the
females of the same form, but are invariably ornamented with stripes and
patches of white or buff, occupying the larger part of the surface of
the hind wings. This peculiarity of colouring led me to discover that
this extraordinary female closely resembles (when flying) another
butterfly of the same genus but of a different group (Papilio cooen), and
that we have here a case of mimicry similar to those so well illustrated
and explained by Mr. Bates.[ Trans. Linn. Soc. vol. xviii. p. 495;
"Naturalist on the Amazons," vol. i. p. 290.]

That the resemblance is not accidental is sufficiently proved by the
fact, that in the North of India, where Papilio cooen is replaced by all
allied forms, (Papilio Doubledayi) having red spots in place of yellow,
a closely-allied species or variety of Papilio memnon (P. androgens)
has the tailed female also red spotted. The use and reason of this
resemblance appears to be that the butterflies imitated belong to a
section of the genus Papilio which from some cause or other are not
attacked by birds, and by so closely resembling these in form and colour
the female of Memnon and its ally, also escape persecution. Two other
species of this same section (Papilio antiphus and Papilio polyphontes)
are so closely imitated by two female forms of Papilio theseus (which
comes in the same section with Memnon), that they completely deceived
the Dutch entomologist De Haan, and he accordingly classed them as the
same species!

But the most curious fact conn