Page:Insects - Their Ways and Means of Living.djvu/341

 CATERPILI.AR AND THE MOTH

structure. On account of its large size, as compared with the size of the cocoon, the caterpillar is forced to double on itself to fit its self-imposed cell. Most ofits hairs, how- ever, are brushed off and become interlaced with the threads to forma part of the cocoon fabric. When the spinning is finished, the caterpillar ejects a yellowish, pasty liquid from its intestine, which it smears all over the mner surface of the case; but the substance spreads through the meshes of the silk, where it quickly dries and gives the starchy stiffness to the walls of the finished cocoon. It readi'ly crumbles into a yellow powder, which becomes dusted over the caterpillar within and ftoats off in a small yellow cloud whenever a cocoon is pulled loose from its attachments. The cocoon is the last resting place of the caterpillar. If the insect lires, it will come out of its prison as a moth, leaving the garments of the worm behind. It may, how- ever, be attacked by parasites that will shortly bring about its destruction. But even if it goes through the period of change successfully it nmst remain in the cocoon about three weeks. In the meantime it will be ofinterest to learn something of the structure of a caterpillar, the better to understand some of the details of the process of its trans- formation.

THE STRUCTURE AND PHYSIOLOG" OF THE CATERPILLAR A caterpillar is a young moth that bas carried the idea of the independence of youth to an extreme degree, but which, instead of rising superior toits parents, bas de- generated into the form of a worm. An excellent theme this would furnish to those who at present are bewailing what they believe to be a shocking tendency toward an excess of independence on the part of the young of the human species; but the moral aspect of the lesson some- what loses its force when we learn that this freedom of the caterpillar from parental restraint gives advantages to both young and adults and therefore results in good to [ -83 ]

INSECTS