548 
Annual Report of New York 
out broader than the confined part, and very soft and bright green. 
The hooka of the hind feet being securely fastened in the threads of 
tlie carpet on which the worm stands, it now with its liberated anterior 
feet dra ws itself slowly and gently forward, with some slight writhings, 
thus freeing more of the body from the old skin. And now at the tip 
of the body a portion of the 6kin is seen to be evacuated, the end of 
the body being slipped forward out of it, and only the gray membrane 
remains there. This membrane is so thin and soft that it sinks down 
flat upon the leaf, as the end of the body is drawn out of it farther 
and farther by the worm continuing to crawl forward. In two 
minutes from the time the skin is first rent open around the neck, 
the body becomes wholly released from it. The skull of the old head, 
however, still remains upon the mouth of the worm, clinging thereto 
with much tenacity. To loosen and detach it the worm repeatedly 
rubs and presses it against an elevated vein of the leaf or any other 
projection it finds, persevering in its efforts until it at length succeeds, 
two minutes more being usually spent in releasing the mouth from 
this encumbrance. 
It then rests, standing on the leaf with the skull of the old head in 
front of it, and the cast skin behind it. The latter is about half the 
length of its body, and is a flattened gray film, notched at its hind 
end, rounded in front and turned upward along each side. The worm 
remains at rest commonly about an hour. It then steps forward 
to the old skull and crowding against it with its head rolls it off 
from the leaf. It next turns around and walking back to the cast 
skin commences eating it, wholly consuming it in about five 
minutes. After this it again rests an hour or more. It then wanders 
away and goes to feeding on the leaves. 
These cabbage worms have a different aspect when they are 
approaching maturity from that which they present during the earlier 
stages of their life. When young their skin is glossy and shining, 
and they are then more slender and their form cylindrical. This 
glossiness entirely disappears later in life, and the surface has a pecu¬ 
liar, somewhat velvety appearance, and the body becomes relatively 
thicker, with a more robust look, and perceptibly tapers from the 
middle toward each end. 
When fully matured, these worms are quite uniformly an inch and 
one-tenth in length; but specimens one-tenth of an inch longer are 
sometimes met with. They are usually one-tenth of an inch shorter, 
or more, when they are at rest than when crawling. 
