It had not, however, been contented with the bare walls of the retreat which it had hewn out of the tree, for it had lined it with a fabric as thick as coarse broadcloth, and equally warm, composed of the raspings of the wood scooped out of the cell, united with the strong silk which every species of caterpillar can spin. In this snug retreat our caterpillar, if it had not been disturbed, would have spent the winter without eating; but upon being removed into a warm room and placed under a glass along with some pieces of wood, which it might eat if so inclined, it was roused for a time from its dormant state, and began to move about. It was not long, however, in constructing a new cell for itself, no less ingenious than the former. It either could not gnaw into the fir plank, where it was now placed with a glass above it, or it did not choose to do so; for it left it untouched, and made it the basis of the edifice it began to construct. It formed, in fact, a covering for itself precisely like the one from which we had dislodged it,--composed of raspings of wood detached for the purpose from what had been given it as food, the largest piece of which was employed as a substantial covering and protection for the whole. It remained in this retreat, motionless, and without food, till revived by the warmth of the ensuing spring, when it gnawed its way out, and began to eat voraciously, to make up for its long fast. [Illustration: Nest of Goat-Moth.--Figured from specimen, and raised to show the Pupa.] These caterpillars are three years in arriving at their final change into the winged state; but as the one just mentioned was nearly full grown, it began, in the month of May, to prepare a cell, in which it might undergo its metamorphosis. Whether it had actually improved its skill in architecture by its previous experience we will not undertake to say, but its second cell was greatly superior to the first. In the first there was only one large piece of wood employed; in the second, two pieces were placed in such a manner as to support each other, and beneath the angle thus formed an oblong structure was made, composed, as before, of wood-raspings and silk, but much stronger in texture than the winter cell. In a few weeks (four, if we recollect aright) the moth came forth. (J. R.) [I have now before me a series of three cocoons, made by one caterpillar of the goat-moth, showing its increase in size during the three years that it remained in the larval state. They were found in an old willow tree, and occupied different parts of the same burrow. The ravages which a goat-moth caterpillar can make in a tree are almost incredible to those who have not seen the long and tortuous burrows which the insect will construct, burrows which at first are small and insignificant, but which afterwards become large enough to admit a man's finger.