of certain kinds of flies may often be found huddled together in great
masses. The larvæ of a few butterflies also live over winter beneath
chips or bunches of leaves near the roots of their food plant, or in
webs of their own construction, which are woven on the stems close to
the buds, whose expanding leaves will furnish them their first meal in
spring.

Many insects pass the winter in the quiescent or pupal stage; a state
exceedingly well fitted for hibernating, requiring as it does, no
food, and giving plenty of time for the marvellous changes which are
then undergone. Some of these pupæ are enclosed in dense silken
cocoons, which are bound to the twigs of the plants upon which the
larvæ feed, and thus they swing securely in their silken hammocks
through all the storms of winter. Perhaps the most common of these is
that of the brown Cecropian moth, _Attacus cecropia_ L., the large
oval cocoon of which is a conspicuous object in the winter on the
twigs of our common shade and fruit trees. Many other pupæ may be
found beneath logs or on the under side of bark, and usually have the
chrysalis surrounded by a thin covering of hairs, which are rather
loosely arranged. A number pass the cold season in the earth with no
protective covering whatever. Among these is a large brown chrysalis
with a long tongue case bent over so as to resemble the handle of a
jug. Every farm boy has ploughed or spaded it up in the spring, and is
it but the pupa of a large sphinx moth, _Protoparce celeus_ Hub., the
larva of which is the great green worm, with a "horn on its tail," so
common on tomato plants in the late summer.

[Illustration: CHRYSALIS OF TOMATO WORM.]

Each of the winter forms of insects above mentioned can withstand long