Curiously enough, in the strict sense of the word “worm,” the boring of chalk and stones by the little marine creature just mentioned (whose name is _Polydora_) is the only instance of a “worm-eaten” condition being produced by a real worm. The worm-eaten condition of wood is produced either by the grub of a minute beetle (which is not in the strict sense a “worm”) or by an ingenious human maker of “antiques” who imitates the little holes on the surface of the woodwork of old furniture, so as to pass off clever reproductions for really ancient cabinet work. The little holes to imitate those of the true insect furniture-borer are sometimes produced by discharging a gun loaded with fine shot at the piece of furniture which is to be passed off as ancient. But knowing purchasers probe the holes so made with a carpet needle, and discover the lead-shot sunk in the wood. Hence there has arisen a profession of specially-skilled “worm-eaters,” who, by careful boring, imitate the holes made by insect grubs. And now we come at last to the actual, real furniture worm or grub. It is the grub of a small beetle—the _Anobium domesticum_, scarcely one-fifth of an inch long (Fig. 62_c_), greyish-brown in colour, of a cylindrical shape, with the head completely concealed or overhung by the next division of the body, the thorax. The grubs are longer, soft, pale, and fleshy. The sign of the presence of the _Anobium_ in your furniture is the existence of small circular holes here and there on the surface of the wood, with occasionally a little heap of yellow dust on the ground beneath them. This last sign is in fact the only proof you can have that the holes are not ancient and the burrows deserted, and that the enemy is still alive and at work. Rarely, if ever, can you see either the grub or the completed beetle into which it changes after forming a cocoon within the burrows, for they very seldom leave their excavations. But if you break up the wood you will find a surprising number of long, cylindrical passages, running side by side, and for many inches, through the deeper part of the wood, so that it may be quite rotten and ready to crumble, although presenting an uninjured surface save for the little round holes here and there. In these passages you will find both the grubs and the adult beetles. [Illustration: FIG. 62.—_a_, the death-watch beetle (_Xestobium tessellatum_) of the natural size (one-third of an inch long); _b_, the same beetle enlarged; _c_, the beetle (_Anobium domesticum_) whose grub is the furniture-worm, of the natural size, a side view.]