THE AURELIA.
When the cocoon is completed, the enclosed caterpillar again casts its skin, with the head and jaws attached to it, when it appears under the form of a conical chrysalis of the ordinary shape. At first the chrysalis, when opened, exhibits only a yellowish fluid, but by degrees the various parts of the future moth appear, and in about a fortnight or three weeks a slight swelling of the chrysalis indicates the approach of another change; a rupture down its back succeeds, and by degrees the moth bursts through its horny coating into the hollow chamber of the cocoon, and if left to itself would soon eat its way out.
WINDING THE SILK.
The chrysalis, however, must be prevented from eating through the cocoon; and previous to the egress of the moth from its aurelian state, the silk must be wound off. When, by taking up the cocoon, it is found that the caterpillar has passed into the aurelian state—which may easily be known by shaking it, as then the aurelia, from its harder texture and shrunken size, will be heard to rattle—then it is time to wind off the silk. The cocoon is placed in a cup of warm water, after the loose outward silk has been removed, and then, an end being taken, the whole continuous filament may be wound off on a piece of card. The length of the thread of a cocoon varies from 600 to 1,000 feet; yet the whole does not weigh more than three grains and a half. An ounce of eggs will produce about 40,000 caterpillars, which will consume 1,073 lbs. of leaves, and produce from 80 lbs. to 100 lbs. of cocoon, or about eight pounds of raw silk.
THE MOTH.
When the silk is wound off the aurelia presents itself, and being put in a separate case, it remains motionless for about twenty days, when suddenly it appears as a pale yellow moth, with wings which seem scarcely adapted for flight. It crawls heavily about the place where it has been hatched, having a slight tremor in its wings, and eats nothing: the male speedily dies; the females hover about a while without flying, and lay their eggs on the slips of paper presented to them for that purpose. They then soon perish. The female moth generally produces about 300 or 400 eggs.
