This frequent coming and going in the shaft threatens sooner or later to bring down the sandy wall. Here we see renewed the industry of the Geotrupes couples, who have a way of plastering the wall of their pit with dung in order to avoid its collapsing while the material of the huge sausage is being amassed on repeated journeys; only, with the Trox, it is the larva itself that undertakes the work of consolidation. From end to end it lines its gallery with the same felt on which it feeds. In three or four weeks’ time, all the hairy materials of the heap have disappeared underground, dragged by the larvæ to the bottom of their burrows. On the surface of the soil nothing is left except the remains of the bones. The adults have gone to earth and are dead or dying. Their time is over. I obtain the first nymphs at midsummer. A glass receptacle shows them to me slowly turning round and round and polishing with their backs the earthy wall of their cell, a simple, oval cavity. By the middle of July the perfect insect has matured. Not yet defiled by the dirt of its calling, it is really magnificent in its ebony cuirass, its strings of large beads surmounted by white hairs, its hinder and middle tarsi shod with bright red. It comes up to the surface, finds the Fox’s dejecta, settles down and from now onward is a filthy scavenger. Once torpid in the sand, under the heap of ordure which serves it as a roof, it will pass the winter there and resume its labours in the spring. When all is said, the Trox is a somewhat uninteresting insect. One single point in her history deserves to be remembered, namely, her predilection for what the Fox’s stomach has refused. I know another instance of these peculiar tastes. The Owl, when he has caught a Field-mouse, stuns her with a blow of his beak on the back of the neck and swallows her whole. It is for the digestive pouch to bone and skin her and sift the bad from the good. When the selection is made—as it is, most admirably—the bird, with a shrug of its body, gets rid of the indigestible stuff; it vomits a pellet of bones and fur. Now, just like the furry mass evacuated by the Fox, these balls of filth have their votaries. I have just seen one of them at work. This is the Choleva tristis, Panz., a dwarf related to the family of the Silphæ. Is the fur of a Rabbit or a Field-mouse such a very precious thing, then, that it has special exploiters appointed to work at it again after the Fox’s intestine and the Owl’s crop have been unable to break it up and use it? Yes, this fur has a certain value. Nature’s treasury claims it for fresh purposes with such an imperious voice that our own industries, which in their fashion are endowed with a terrific power, of digestion, cannot guarantee us the protracted possession of what was a scrap of fluff.