and severe cold weather--in fact, may be frozen solid for weeks and
retain life and vigor, both of which are shown when warm weather and
food appear again. Indeed, it is not an unusually cold winter, but one
of successive thawings and freezings, which is most destructive to
insect life. A mild winter encourages the growth of mould which
attacks the hibernating larvæ and pupæ as soon as, from excess of rain
or humidity, they become sickly; and it also permits the continued
activity of insectivorous mammals and birds. Thus, moles, shrews,
and field mice, instead of burying themselves deeply in the ground,
run about freely during an open winter and destroy enormous numbers
of pupæ; while such birds as the woodpeckers, titmice, and chickadees
are constantly on the alert, and searching in every crevice and cranny
of fence and bark of tree for the hibernating larvæ.

Of the creeping, wingless creatures, which can ever be found beneath
rocks, rails, chunks, and especially beneath those old decaying logs
which are half buried in the rich vegetable mould, the myriapods, or
"thousand-legs," deserve more than a passing notice. They are typical
examples of that great branch of the animal kingdom known as
_arthropods_, which comprises all insects and crustaceans. Each
arthropod has the body composed of rings placed end to end and bearing
jointed appendages, and in the myriapods each ring and its appendages
can be plainly seen; whereas in the higher forms of the branch many of
the rings are so combined as to be very difficult to distinguish.

Full forty kinds of myriapods occur in any area comprising one hundred
square miles in the eastern United States. About twenty-five of them
go by the general name of "thousand-legs" or millipedes, as each has
from forty to fifty-five cylindrical rings in the body, and two pairs
of legs to each ring. The other fifteen belong to the "centipede"