perceive that this is
the means of getting air.

Observe the rapid movement toward the bottom when disturbed; the means
of causing this movement; the change into the large-headed pupae--a
change which takes place about ten days after hatching; the almost
motionless character of the pupae; the change from the pupae forms into
the adult--a change which takes place at about the fourth day of pupae
life.

Put some mosquito larvae (wigglers) into the fish aquarium. Are
mosquitoes of any use? The wigglers are the food on which some young
fishes live. Young bass and trout feed upon them.

Put some kerosene on the surface of a jar in which there are mosquito
larvae. Describe a method of destroying mosquitoes.

The teacher tells about the mosquito as the cause of the spread of
malaria. From the fact that the eggs hatch on stagnant water, deduce a
benefit arising from the draining of land.

REFERENCES

Silcox and Stevenson: _Modern Nature Study_

Hodge: _Nature Study and Life_

CADDICE-FLY

Time: May.

The caddice-flies are very interesting insects, owing to the habits of
the larvae of building little cases of wood, stones, or shells, in which
they pass their development stages under water.

These larvae are easily found during the month of May in little streams
of water everywhere throughout the Province. Look for what at first
sight appears to be a bit of twig or a cylinder of stone about an inch
long moving along the bottom as though carried by currents. Closer
observation will result in the discovery that this is a little case
composed of grains, of bits of stick, or of sand and tiny shells, and
the head of the occupant may be seen projecting from one end.

Collect some of these larvae in a jar of water and transfer them to the
aquarium. Direct the pupils to look for others in the streams, so that
they may observe their appearances and movements in their natural
environment. If kept in jars, the water must be changed every day, and
the top should be covered to prevent the escape of the adults.

~Observe.~--The shape of the various kinds of cases; the materials, and
how fastened together (chiefly by silk); the part of the larva that
protrudes from the case; the movement, and how caused; the fitness of
the case as a protection. Note hardness, colour, and shape as protective
features.

The pupils will be fortunate if they observe the sudden rise of the
larva to the surface of the water and the almost instanta