and feeding on the roots of plants, especially the roots of grains and
grasses.

Since they are found chiefly in fields recently ploughed from grass,
they may be held in check by rotation of crops and by fall ploughing,
which exposes the larvae to the winter frosts.

In May or June, when the adults are feeding on the foliage of fruit and
shade trees, spraying the trees with London purple is quite effective
for destroying the beetles before they have laid their eggs among the
roots of the grass.

Hogs destroy many larvae by rooting in the soil to find them for food.

CRAYFISH

Search for the crayfish in streams and ponds. Why is the crayfish hard
to find? Hard to capture?

Obtain a living crayfish from a pond or stream and place it in a jar of
water or in an aquarium.

The crayfish should not be placed in an aquarium containing insects and
small fish which are to be kept, as it is fierce and voracious.

The pupils should study the living animal, noting its habit of lurking
under stones; the sweeping of the water with the feelers; the backward
movement in swimming, produced by bending the tail sharply underneath
the body; the walking by means of four pairs of legs, the great claws
being used to turn the animal; the use of the great claws in seizing
prey and holding food near the mouth; the movements of the small
appendages under the front part of the animal and the water currents
caused by these; the movements of the small appendages under the abdomen
of the animal.

FRESHWATER MUSSEL

The freshwater mussel--"clam" as it is usually called by
school-boys--may be found in almost any stream.

Place a mussel in the aquarium, and note the opening and closing of the
valves of the shell; the hinge connecting the valves; the foot
protruding from the shell; the movements by means of the foot; the
mantle lobes lining the shell and visible at the open margins; the two
siphons at the rear of the animal--water currents may be observed
entering the upper and emerging from the lower of these. Infer uses for
these currents. Touch the edge of the upper siphon and observe how
quickly the shell is closed.

Compare the mussel with the snail as to movements and shell.

Compare also with the oyster and sea clam.

Examine empty shells and notice the pearly layer of the shell, the
action of the hinge, and the marks on the shell to which the muscles for
closing the shell were attached.

State all the means of protection that