Direct the observations of the pupils to the following type features:
Brownish or grayish colours; fringe of long bristles around the mouth (explain their use); whistling notes, varying with the different members of the family; habit of jumping from the perch, catching an insect while on the wing, and returning to the spot from which the flight began; nests, chiefly of mud built in a protected place, as under a bridge, ledge of rock, or projecting log.
WRENS
The house wren may be studied as a type. Observe its brownish colour, faintly mottled; its small size and energetic movements, its tail turned nearly vertically upward. Observe and report on other wrens, noting any differences.
CABBAGE-BUTTERFLY
Have a plant of wild mustard or a cabbage growing in a pot. In June, have the pupils, by means of the insect net, catch a number of the white butterflies, the adults of the cabbage-worm.
Place the butterflies in jars or bottles and observe them. Make drawings of them.
Direct the attention of the pupils to the difference between the wings of the male and those of the female. The former has only one dark spot on the front wing, while the female has two spots on this wing.
Release the males and put the females in a vivarium with the potted plant. (A pasteboard box, with a large piece cut out and the opening covered with gauze, makes a good substitute for a vivarium in this case.)
Observe the laying of the eggs. How many are placed at one spot? How are the eggs protected? The eggs may be gathered from the cabbage plants in the garden.