After a time the pieces are longer and more carefully chosen, and are all laid on lengthwise. The placing of a straw is done with surprising speed and skill. The Caterpillar turns it round and round between his legs, and then, gripping it in his mandibles, removes a few morsels from one end, and immediately fixes them to the end of the sack. He probably does this in order that the silk may obtain a firmer hold, as a plumber gives a touch of the file to a point that is to be soldered. Then, by sheer strength of jaw, he lifts and brandishes his straw in the air before laying it on his back. At once the spinneret sets to work and fixes it in place. Without any groping about or correcting, the thing is done. By the time the cold weather arrives the warm case is complete. But the silky felt of the interior is never thick enough to please the Caterpillar. When spring comes he spends all his spare time in improving his quilt, in making it ever thicker and softer. Even if I take off his outer case he refuses to rebuild it: he persists in adding new layers to the lining, even when there is nothing to be lined. The sack is lamentably flabby; it sags and rumples. He has no protection nor shelter. No matter. The hour for carpentry has passed. The hour has come for upholstering; and he upholsters obstinately, padding a house—or lining a garment—that no longer exists. He will perish miserably, cut up by the Ants, as the result of his too-rigid instinct. CHAPTER VIII THE SELF-DENIAL OF THE SPANISH COPRIS You remember, I hope, the Sacred Beetle, who spends her time in making balls, both to serve as food and also to be the foundation of her pear-shaped nest. I pointed out the advantages of this shape for the young Beetles, since the globe is the best form that could be invented to keep their provisions from becoming dry and hard. After watching this Beetle at work for a long time I began to wonder if I had not perhaps been mistaken in admiring her instinct so greatly. Was it really care for her grubs, I asked myself, that taught her to provide them with the tenderest and most suitable food? It is the trade of the Sacred Beetle to make balls. Is it wonderful that she should continue her ball-making underground? A creature built with long curved legs, very useful for rolling balls across the fields, will go on with her favourite occupation wherever she may be, without regard to her grubs. Perhaps the shape of the pear is mere chance. To settle this question satisfactorily in my own mind I should need to be shown a Scavenger Beetle who was utterly unfamiliar with the ball-making business in everyday life, and who yet, when laying-time was at hand, made an abrupt change in her habits and stored her provisions in the form of a round lump. That would show me that it was not merely custom, but care for her grubs, that made her choose the globular shape for her nest.