STATES OF INSECTS. (Pupa.) 283 
by Professor Peck, has a different process. ‘In the 
silk-moth,” says he, “and all others which I have had 
opportunity to observe, the chrysalis bursts zz the co- 
coon, and the fluid which surrounded the new insect in 
it escaping at the same time, so weakens or dissolves the 
fibre and texture of the silk, that the moth is able to ex- 
tricate itself, leaving the chrysalis behind it; but this is 
not the manner in the locust-moth. After remaining till 
all its parts are fully grown and it is ready to quit its 
prison, a certain quantity of exercise is necessary, to 
break the ligaments which attach the moth to the shell 
of the chrysalis, and to loosen the folds of the abdomen. 
_ In taking this exercise, it can only move the abdomen in 
various directions: as one side of the rings is moved for- 
ward, the hooks in the serrated lines above mentioned 
(the adminicula) take hold of the silk, and prevent their 
sliding back; the next flexure brings forward the oppo- 
site side of the rings, which are prevented by the points 
on that side from slipping back in the same manner, and 
the chrysalis is forced out of the slightly woven extremity 
of the cocoon, and through the silk-lined cavity, till it is 
protruded for about one-third of its length out of the 
opening in the bark, and into the air*.” 
An exception to the general rule—that the rupturing 
of the cocoon is the business of the inclosed insect itself 
—is met with amongst ants; the workers of which not 
only feed the young, but actually make an aperture in 
their cocoons, cutting the threads with their mandibles 
with admirable dexterity and patience, one by one, at 
“ Some Notice of the Insect which destroys the Locust-trees, 70. 
This Memoir is in some American periodical work, of which I have 
not the title. 
