Among the Lycosidae or “Wolf-spiders” the prevailing habit of the mother is to carry the egg-bag attached beneath her abdomen upon all her hunting excursions. It is spheroidal in shape, made up of an upper and a lower half, with a seam-like junction at the equator, so to speak. The lower half is first woven, and the eggs are deposited within it. The upper hemisphere is then spun, and the edges gathered in and finished off, the seam or suture being always discernible. The bag is now attached by silken threads to the spinnerets, and bumps merrily over the ground as the animal hurries along in search of prey. If deprived of it she evinces the greatest distress, and frequently will not try to escape without it. =Attempts to utilise Spider Silk.=—It is long since the web of the House-spider, taken internally, was considered a specific for the ague, though its value as a styptic has been recognised in quite recent times. It is, however, with other uses of Spider silk that we are here concerned. Spider silk has been extensively used in the micrometer eyepieces of telescopes where very fine intersecting lines are required. For this purpose the radial or scaffolding lines of the circular snare were selected, the spiral being unsuited on account of its row of viscid beads. Professor C. V. Boys has, however, discovered in his quartz fibres a material better adapted for this purpose. Several attempts have been made to weave the silk of Spiders as a substitute for that of the silk-worm. Web silk is, of course, far too fine to furnish a durable material, but the cocoons are usually formed of coarser silk, and it is with them that the experiment has been tried. About the beginning of the eighteenth century certain stockings and mittens made of Spider silk from the cocoons of _Epeira diademata_, by M. Bon of Languedoc, attracted so much attention that the Academy desired M. Réaumur to investigate the matter. His report was unfavourable to the commercial utility of Spider silk. The cocoon threads, though eighteen times stronger than those of the web, were but one-fifth of the strength of those obtained from the silk-worm, and the lustre was inferior. A still more fatal objection, however, was founded upon the cannibalistic habits of the spider, and the difficulty of furnishing it with acceptable food. M. Vinson has recorded that some of the spiders of Madagascar, especially _Epeira madagascarensis_, are far better adapted than any of our English species to a commercial use. They furnish silk of a beautiful clear yellow colour; they are accustomed to live harmoniously together in families; and the range of climate in which they can thrive is very considerable. The Creole ladies of this island, under the administration of General Decaen, wove a magnificent pair of gloves from spider silk, with their own hands, for presentation to the French Empress.