THE AMERICAN SILK WORM. 37 
The Polyphemus worm, like all other silk worms, chang- 
es its skin five times during its larval life. The moulting 
takes place at regular periods, which come around about 
every ten days for the first four moultings, while about 
twenty days elapse between the fourth and fifth moulting. 
The worm ceases to eat for a day before moulting, fiid 
spins some silk on the vein of tlfe under surface of a leaf; 
it then secures the hooks of its hind legs in the texture it — 
has thus spun, and there remains mòtikis y soon after, 
through the transparency of the skin of the neck, can be 
seen a second head larger than the first, belonging to the 
larva within. The moulting generally takes place after 
four o’clock in the afternoon; a little before this time the 
worm holds its body erect, grasping the leaf with the two 
pairs of hind legs only ; the skin is wrinkled and detached 
from the body by a fluid which circulates between it and 
the worm; two longitudinal white bands are seen on each 
side, produced by a portion of the lining of the spiracles, 
which at this moment have been partly detached ; mean- 
while the contractions of the worm are very energetic, and 
by it the skin is pulled off and pushed towards the poste- 
rior part; the skin thus becomes so extended that it soon 
tears, first under the neck, and then from the head. When 
this is accomplished the most difficult operation is over, 
and now the process of moulting goes on very rapidly. 
By repeated contractions the skin is folded towards the 
tail, like a glove when taken off, and the lining of the spir- 
acles comes out in long white filaments. When about one- 
half of the body appears, the shell still remains like a 
eap, enclosing the jaws, then the worm as if reminded of 
this loose skull-eap, removes it by rubbing it on a leaf; 
this done, the worm finally crawls out of its skin, which: 
is attached to the fastening made for the purpose. Once 
