the open winter of 1888–89 numerous specimens of leopard and green
frogs were seen on different occasions in December and January, while
on February 18th they, together with the "peepers," were in full
chorus.

Of our mammals, a few of the rodents or gnawers, as the ground-hogs,
gophers and chipmunks, hibernate in burrows deep enough to escape the
cold, and either feed on a stored supply of food, or, like the snakes
and crayfish, do not feed at all.

[Illustration: CHIPMUNK.]

Others, as the rabbits, field-mice, and squirrels, are more or less
active and forage freely on whatever they can find, eating many things
which in summer they would spurn with scorn. To this class belongs
that intelligent but injurious animal the musquash or muskrat. Those
which inhabit the rivers and larger streams live in burrows dug deep
beneath the banks, but those inhabiting sluggish streams and ponds
usually construct a conical winter house about three feet in diameter
and from two to three feet in height. These houses are made of coarse
grasses, rushes, branches of shrubs, and small pieces of driftwood,
closely cemented together with stiff, clayey mud. The top of the house
usually projects two feet or more above the water, and when sun-dried
is so strong as to easily sustain the weight of a man. The walls are
generally about six inches in thickness and are very difficult to pull
to pieces. Within is a single circular chamber with a shelf or floor
of mud, sticks, leaves and grass, ingeniously supported on coarse
sticks stuck endwise into the mud after the manner of piles. In the
centre of this floor is an opening, from which six or eight diverging
paths lead to the open water without, so that the little artisan has