STATES OF INSECTS. (Jmago.) 291 
hairy crust which it will turn to in an hour or two: and 
the wings, instead of being a thin, transparent, expand- 
ed film, are contracted into a thick, opaque, wrinkled 
mass. 
These symptoms of debility and imperfection, how- 
ever, in most cases speedily vanish. The insect, fixing 
itself on the spoils of the pupa, or some other convenient 
neighbouring support, first stretches out one organ, and 
then another: the moisture of its skin evaporates, the 
texture becomes firm, the colours come forth in all their 
beauty ; the hairs and scales assume their natural posi- 
tion; and the wings expanding, extend often to five or 
six times their former size—exhibiting, as if by magic, 
either the thin transparent membranes of the bee or fly, 
or the painted and scaly films of the butterfly, or moth, 
or the coloured shells of the beetle. The proceedings 
here described I witnessed very recently with regard to 
a very interesting and beautiful butterfly, the only one of 
its description that Britain has yet been ascertained to 
produce—I mean Papilio Machaon. The pupa of this 
being brought to me by a friend early in May this year 
(1822), on the sixteenth of that month I had the pleasure 
to see it leave its puparium. With great care I placed it 
upon my arm, where it kept pacing about for the space 
of more than an hour; when all its parts appearing con- 
solidated and developed, and the animal perfect in beauty, 
I secured it, though not without great reluctance, for my 
cabinet—it being the only living specimen of this fine fly 
I had ever seen. To observe how gradual, and yet how 
rapid, was the development of the parts and organs, and 
particularly of the wings, and the perfect coming forth of 
the colours and spots, as the sun gave vigour to it, was a 
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