[Illustration: LACE-FLY AND EGGS.] Many Spiders enclose their eggs in an envelope, the produce of their own bowels. Take an interesting example, as narrated by the eloquent Mr. Kirby. "There is a Spider common under clods of earth (_Lycosa saccata_), which may at once be distinguished by a white globular silken bag, about the size of a pea, in which she has deposited her eggs, attached to the extremity of her body. Never miser clung to his treasure with more tenacious solicitude than this spider to her bag. Though apparently a considerable incumbrance, she carries it with her everywhere. If you deprive her of it, she makes the most strenuous efforts for its recovery; and no personal danger can force her to quit the precious load. Are her efforts ineffectual? a stupefying melancholy seems to seize her; and, when deprived of this first object of her cares, existence itself appears to have lost its charms. If she succeeds in regaining her bag, or you restore it to her, her actions demonstrate the excess of her joy. She eagerly seizes it, and with the utmost agility runs off with it to a place of security. "The attachment of this affectionate mother is not confined to her eggs. After the young spiders are hatched, they make their way out of the bag by an orifice which she is careful to open for them, and without which they could never escape; and then, like the young of the Surinam toad (_Rana pipa_), they attach themselves in clusters upon her back, belly, head, and even legs; and in this situation, where they present a very singular appearance, she carries them about with her, and feeds them until their first moult, when they are big enough to provide their own subsistence."[94] I waive the argument derived from the fact of the apparent necessity of the mother's care for the new-born young. But the mother's care is indispensable to the appearance of the young at all; not only because the eggs are the produce of her ovary, but also because the envelope which protects them is the produce of her spinning-glands. There is a furry moth, by no means uncommon, known to collectors as the Gipsy (_Hypogymna dispar_), the eggs of which require to be protected by an elaborate covering, either from extremes of temperature, from light, or from certain electric conditions of the atmosphere. The protection is afforded at the expense of the hair which clothed the mother herself. Her ovipositor is furnished with a pair of nippers, by means of which she plucks off her own hairs, and makes with them a flat cushion on the surface of a leaf. On this she deposits her eggs in successive layers; and when the full number is laid, she covers them with a roof of hair, slanting downwards and outwards from an apex, so artfully arranged, like the thatch of a cottage, as effectually to throw off water; each layer of hairs overlapping the preceding, and all preserving the same direction, so that, when finished, the work resembles a smooth and well brushed piece of fur.