Did you ever see a fish yawn? Watch a shiner in your aquarium. Sometimes you may see him open his mouth widely as though he was very sleepy. Again you may find him resting on the bottom of the jar taking a nap. Fishes cannot close their eyes when they sleep for they have no eyelids.
A convenient way to collect fishes for the schoolroom aquarium is to use a dip net. The ordinary insect net will do, but it is better to replace the cheese-cloth bag by a double thickness of mosquito-bar, thus enabling one to move the net through the water more rapidly. By dipping in the deep pools, among grasses and under the banks with such a net one can soon obtain fishes enough to stock an aquarium ([Fig. 86]). The aquarium jar should never be placed in the sun. It is better to have only three or four fishes in an aquarium at one time. Some flat stones on the bottom of the jar will afford them convenient hiding places.
For further notes on aquaria, consult Leaflet No. XII.
LEAFLET XIV.
THE OPENING OF A COCOON.[18]
By MARY ROGERS MILLER.
Among the commonest treasures brought into the schools by children in the fall or winter are the cocoons of our giant silk-worms. If one has a place to put them where the air is not too warm or dry, no special care will be necessary to keep them through the winter. Out-door conditions must be imitated as nearly as possible. If early in the fall one is fortunate enough to meet one of these giants out for a walk, it is the simplest thing in the world to capture him and watch him spin his marvelous winter blanket. Two members of this family of giant insects are quite common in this state, the largest the Cecropia, called sometimes the Emperor, and the Promethea.