Things had been in this state since the previous evening, when I heard the larva scratching in the box. On opening, I found my captive busy scratching the cardboard walls with the tips of its mandibles, its body half out of the bag. Already it had made considerable progress, and a heap of little fragments were piled before the opening of the hammock, to be utilised later. For lack of other materials it would doubtless have used these scrapings for its constructions, but I thought it better to provide according to its tastes and give it sand. Never did Bembex larva build with such sumptuous material. I poured out for my prisoner sand for drying writing,—sand well sprinkled with gilded grains of mica,—before the opening of the bag, which was in a horizontal position, suitable to the work which would follow. The larva, half out of its hammock, chose its sand almost grain by grain, routing in the heap with its mandibles, and, if one too bulky presented itself, it was seized and cast aside. The sand being sorted, the larva introduced a certain quantity with its mouth into the silken fabric, then retired into its sack and began spreading the materials in a uniform layer on the inner surface, then glued together various grains and inlaid them in the fabric, with silk for cement. The outer surface was constructed more slowly. These grains were carried singly and fixed on with silk gum. This first deposit of sand only concerns the anterior part of the cocoon—that half which ends in the opening. Before turning round to work at the back part, the larva renews its store of materials and takes certain precautions, so as not to be embarrassed in its masonry. The sand heaped before the entrance might slip inside and hinder the builder in so narrow a space. The grub foresees this, and glues some grains together, making a coarse curtain of sand, which stops up the orifice, imperfectly indeed, but enough for the purpose. These precautions taken, the grub labours at the back part of the cocoon. From time to time it turns round to get fresh materials from outside, tearing away a corner of the protecting curtain, and through this window grasping the materials needed. The cocoon is still incomplete—wide open at the upper end and without the spherical cap needed to close it. For this final bit of work the grub provides itself abundantly with sand, and then pushes away the heap before the entrance. A silken cap is now woven and fitted close to the mouth of this primitive basket. On this silken foundation are deposited, one by one, the sand grains kept in the interior and cemented with silk-spittle. This lid completed, the larva has only to give the last finish to the interior of the dwelling and glaze the walls with varnish, to protect its tender skin from the roughness of the sand.