Things had been in this condition since the day before, when I heard the larva scratching in the box. I opened it and found my prisoner engaged in scraping the cardboard wall with its mandibles, while its body was half outside the sack. The cardboard had already suffered considerably and a heap of tiny fragments were piled in front of the opening of the hammock, to be used later. For lack of other materials, the grub would doubtless have employed these scrapings for its building. I thought it better to provide something in accordance with its tastes and to give it sand. Never had Bembex-larva built with such sumptuous materials. I poured before the captive sand from my ink-stand: blotting-sand, blue sand sprinkled with little gilt mica spangles. This supply is placed in front of the mouth of the bag. The bag itself is in a horizontal position, which is convenient for the coming task. The larva, leaning half out of the hammock, picks up its sand almost grain by grain, rummaging in the heap with its mandibles. If any grain is found to be too bulky, the grub takes it and throws it away. When the sand is thus sorted, the larva introduces a certain quantity into the silken edifice by sweeping it with its mouth. This done, it retires into the eel-trap and begins to spread the materials in a uniform layer on the lower surface of the sack; then it gums the different grains and inlays them in the fabric, using silk as cement. The upper surface is built more slowly: the grains are carried up one by one and fixed on with the silken putty. This first layer of sand as yet embraces only the front half of the cocoon, the half that ends at the mouth of the bag. Before turning round to work at the back half, the grub renews its supply of materials and takes certain precautions so as not to be hindered in its mason’s work. The sand outside, heaped up in front of the entrance, might slip inside and embarrass the builder in so narrow a space. The grub foresees this possibility: it glues a few grains together and makes a rough curtain of sand, which stops up the orifice very imperfectly, but sufficiently to prevent an accident. Having taken these precautions, the larva works at the back half of the cocoon. From time to time it turns round to fetch fresh supplies from outside, tearing a corner of the curtain that protects it against the outer sand and grabbing through this window the materials which it requires.