Fig. 158.—Foot of a fly.
Fig. 159.—Breathing tubes of an insect.
Fig. 160.—Grasshopper, showing spiracles, s.
The insects, with some exceptions, deposit eggs, and the young pass through many strange changes, or metamorphoses, before the full-grown form is attained. The eggs of beetles hatch into larvæ (Fig. 162), which may live weeks or months or even years in the ground. The eggs of other insects, as moths, may become caterpillars, which finally spin a cocoon, as in the case of the silkworm, and from this cell-like room appears the perfect moth. These changes, so infinite in their variety, are among the most interesting features of insect life, and are never failing sources of wonder and amazement on the part of those who devote time to the study.
Fig. 161.—Breathing hole or spiracle, highly magnified.
Fig. 162.—Larvæ of insects.