212 
SECOND BOOK. 
INSECTS (pp. 46-52). 
Structure. — The body is divided into three distinct parts: 
1. Head ; bearing the eyes, feelers, and jaws. 
2. Thorax (or chest); formed of three segments, and bearing three pairs 
of legs, and two pairs of wings (generally). 
3. Abdomen (or belly) ; having a varying number of segments, and 
without legs or wings. 
Breathing. — Insects have neither gills nor lungs. They breathe by 
means of tubes, which open in the sides of the body. 
Metamorphosis- — By this is meant the great changes that most 
insects undergo before they reach a perfect state. 
Some insects have three stages of development, viz.: 
1. The grub, caterpillar , or maggot stage; in which eating is almost the 
only kind of work done. 
2. The chrysalis or pupa stage ; in which the grub goes into a cocoon of 
its own making, and rests for a time. 
3. The perfect insect or imago stage ; in which the insect has its com- 
plete form. In this stage the female lays eggs, from which the grubs (or 
caterpillars or maggots) emerge in due time. 
Uses of Insects: 
1. Bees make wax and honey. 
2. Insects fertilize flowers ( e.g . bees, &c.). 
3. They clear up decaying matter (e.g. beetles). 
4. They loosen and stir the soil (e.g. ants). 
5. The caterpillar of the silk moth spins silk. 
Insects as Pests: 
1. Insects destroy or disturb roots of plants. 
2. They feed on leaves or juices of plants. 
3. The grubs bore into stems and roots. 
4. Insects eat the wood of houses and furniture. 
5. They plague domestic animals. 
Part II.— PLANT LIFE. 
THE PABTS OF A FLOWED (p. 53). 
A complete flower has — 
1. Sepals ; which form the calyx. 
2. Petals ; which form the corolla. 
3. Stamens; which have anthers , containing pollen. 
