If desirable, they can be made to build their new houses of most singular materials. A lady, Miss Smee, was very successful in a series of experiments which she made with these insects, forcing them to make tubes of different colours and patterns, by supplying them with coloured sand, pieces of stained glass of various hues, gold dust, and similar materials. Although there was scarcely any material which they would not use, they seemed to consider a certain amount of angularity as essential, and rejected any object, such as a bead, of which the surface was perfectly rounded, while they would accept the same, if it were broken or indented. When the caddis-grub has ceased from feeding, and is about to pass into the perfect stage, it spins over the mouth of the tube a strong silken web. This web is made in quite a pretty pattern, and being woven with rather wide meshes, it allows the water to flow through the tube while it prevents any aquatic foes from penetrating and destroying the pupa. The remaining figures of the illustration represent tubes, around which are built a quantity of small shells. Generally, stones are mixed with the shells; but in some cases, shells seem to be almost the only material.] Carpenter-Caterpillars. Insects, though sometimes actuated by an instinct apparently blind, unintelligent, or unknown to themselves, manifest in other instances a remarkable adaptation of means to ends. We have it in our power to exemplify this in a striking manner by the proceedings of the caterpillar of a goat-moth (_Cossus ligniperda_) which we kept till it underwent its final change. This caterpillar, which abounds in Kent and many other parts of the island, feeds on the wood of willows, oaks, poplars, and other trees, in which it eats extensive galleries; but it is not contented with the protection afforded by these galleries during the colder months of winter, before the arrival of which it scoops out a hollow in the tree, if it does not find one ready prepared, sufficiently large to contain its body in a bent or somewhat coiled-up position. On sawing off a portion of an old poplar in the winter of 1827, we found such a cell with a caterpillar coiled up in it. [Illustration: Caterpillar of Goat-Moth in a Willow Tree.] [Illustration: Winter Nest of the Goat-Caterpillar.]