DEVELOPMENT 7 
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mouth, wetting the inside of the cocoon. The process of ex- 
clusion from the cocoon lasts for as much as half an hour. 
The insect seems to be instinctively aware [?] that some time 
is required to dissolve the gum, as it does not make any attempt 
to open the fibres, and seems to wait with patience this event. 
When the liquid has fully penetrated the cocoon, the pupa con- 
tracts its body, and pressing the hinder end, which is furnished 
with little hooks, against the inside of the cocoon, forcibly 
extends its body; at the same time the head pushes hard upon 
the fibres and a little swelling is observed on the outside. 
These contractions and extensions of the body are repeated 
many times, and more fluid is added to soften the gum, until 
under these efforts the cocoon swells, and finally the fibres 
separate, and out comes the head of the moth. In an instant 
the legs are thrust out, and then the whole body appears; not 
a fibre has been broken, they have only been separated. 
“To observe these phenomena, I had cut open with a razor 
a small portion of a cocoon in which was a living chrysalis 
nearly ready to transform. The opening made was covered 
with a piece of mica, of the same shape as the aperture, and 
fixed to the cocoon with mastic so as to make it solid and air- 
tight; through the transparent mica, I could see the move- 
ments of the chrysalis perfectly well. 
“When the insect is out of the cocoon, it immediately seeks 
for a suitable place to attach its claws, so that the wings may 
hang down, and by their own weight aid the action of the 
fluids in developing and unfolding the very short and small 
pad-like wings. Every part of the insect on leaving the co- 
coon, 1s perfect and with the form and size of maturity, except 
the pad-lke wings and swollen and elongated abdomen, which 
still gives the insect a worm-like appearance ; the abdomen con- 
tains the fluids which flow to the wings. 
“When the still immature moth has found a suitable place, 
it remains quiet for a few minutes, and then the wings are seen 
to grow very rapidly by the afflux of the fluids from the abdo- 
men. In about twenty minutes the wings attain their full 
