These arguments the Balaninus meets with a refusal. It shifts its quarters, and it is right. On the ground, where the nut is lying, it has reason, to begin with, to dread the Field-mouse, a great hoarder of nuts. He collects in his stone-heap everything yielded by his nightly rounds; then, at his leisure, with a patient tooth, he pierces a small hole in the shell and extracts the kernel. The hazel-nut is a welcome find, a savoury morsel. If emptied by the Weevil, it is only the more valuable: instead of its usual contents it contains the grub of the Balaninus, a rich saveloy which makes a pleasant change from a farinaceous diet. So, for fear of the Field-mouse, we go underground. A still more important motive urges this departure. True, it would be pleasant to sleep in the impregnable castle of the nut-shell; but the delivery of the future insect has also to be thought of. The larva of the Capricorn, throwing caution to the winds, leaves the interior of the oak and comes to the surface, risking the investigations of the Woodpecker; it runs into danger to prepare an exit for the great horned Beetle, who could not make his way out unaided. A similar precaution is necessary for the Weevil-larva. While possessing the full strength of its mandibles, without waiting for the torpor during which the accumulated fats will be remoulded into a new organism, it pierces the coffer from which the adult would be incapable of escaping by her own efforts; it comes out and buries itself in the ground. The future is wisely provided against; from its present catacomb the adult will be able without hindrance to ascend to the light of day. We were saying that, if the Weevil assumed her final shape in the nut, she would be incapable of effecting her own release. Yet with her drill she is very well able to perforate the shell when the egg has to be installed. Why should she be prevented from doing in the inverse direction what she is able to perform inwards from without? A little reflection will show us the tremendous difficulty. To place the egg in position, a fine tube, of the thickness of the drill, is sufficient. To give passage to the solid adult Weevil would demand a comparatively enormous opening. The material to be pierced is very hard, so hard that the larva, with the powerful gouges of its mandibles, bores a hole only just big enough to allow the head to pass. The rest of the body has to follow by dint of exhausting efforts. How could the insect open a sufficiently large door with its delicate foil, when the far better-equipped grub has so much difficulty in boring a moderate porthole? Could she not, by making a ring of perforations, remove a round disk of the requisite size? Strictly speaking, this would be possible, with a prodigious expenditure of patience, a quality which insects can hardly be said to lack.