6 ANIMAL ACTIVITIES. 
Caterpillars. Keep these singly in tumblers with 
fresh supplies of the plant on which they are found 
feeding. When many caterpillars are needed for class 
study a ‘‘breeding-cage’’ may be made by placing 
earth in the bottom of a 
large box, covering the 
box with netting, and 
supplying plenty of food 
and moisture. If panes 
of glass can be set in the 
sides of the box, so much 
the better. Cabbage- 
worms are easily ob- 
tained, and the butterflies 
can be reared from them 
with very little care. The 
cabbage - butterflies are 
sometimes called 
‘‘whites’’. In observ- 
ing butterflies and cater- 
pillars use the questions 
in Chapter V. 
Flies. Allow adult 
bluebottle flies to deposit 
eggs on pieces of meat or 
fish in tumblers. Watch 
Fic. 3.—A Cabbage-butterfty, a, the growth of the eggs. 
larva; 4, pupa; ¢, egg; @, imago. Keep in a fairly warm 
place and furnish mois- 
ture. See further suggestions in Chapter VI. House- 
flies may be watched in tumblers. Feed them on 
sugar and watch their movements. Early in the 
fall house-flies will deposit their eggs on stable- 
manure. 
Spiders. All our common spiders are harmless. 
To collect spiders invert a tumbler over them, and im- 
prison the insects by covering the mouth of the tumbler 
with a card. The garden-spider is a good one to 
