The consumption of leaves is effected with scrupulous economy. Instead of grazing at hazard and using up the pasturage at the dictates of individual caprice, the flock progresses gradually from the base to the tip of the leaf, with all heads ranged in a frontal attack, almost in a straight line. Not a bite is taken beyond this line, until all that lies on this side of it is eaten up. As it advances, the flock throws a few threads across the denuded portion, where nothing remains but the veins and the epidermis of the opposite surface. Thus is woven a gossamer veil serving as a shelter from the fierce rays of the sun and as the parachute which is essential to these weaklings, whom a puff of wind would carry away. As the result of a more rapid desiccation on the ravaged surface, the leaf soon begins to curl of its own accord, curving into a gondola which is covered by a continuous awning stretched from end to end. The herbage is then exhausted. The flock abandons it and begins again elsewhere in the near neighbourhood. After various temporary pastures of this kind, in November, when the cold weather is at hand, the caterpillars settle permanently at the end of a bough. Nibbled one by one on their upper surfaces, the leaves of the terminal bunch draw close to their neighbours, which, excoriated in their turn, do the same, until the whole forms a bundle, which looks as if it had been scorched, lashed together with magnificent white silk. This is the winter habitation, whence the family, still very feeble, will not issue until the fine weather returns. The assembling of this leafy framework is not due to any special industry on the caterpillars’ part; they do not stretch their threads from leaf to leaf and then, by pulling at these ropes, bring the various pieces of the structure into contact. It is merely the result of desiccation on the nibbled surfaces. Fixed cables, it is true, solidly bind together the leaves brought close to one another by the contraction due to their aridity; but they do not in any way play the part of a motive mechanism in the work of the assemblage. No hauling-ropes are here, no capstans to move the timbers. The feeble creatures would be incapable of such effort. The thing happens of itself. Sometimes a floating thread, the plaything of the air, enlaces some adjacent leaf. This chance footbridge tempts the explorers, who hasten to strip the accidental prize; and, without other labour, yet one more leaf bends of its own accord and is added to the enclosure. For the most part, the house is built by eating; a lodging is procured by dint of banqueting.