‘On the ground, amid the intricate obstructions of the grass, my task would be impracticable. I want elbow-room; I want the thing to hang in the air, free from any obstacle. And there is a more important condition: my larva would refuse a rank, withered sausage; it insists on food that retains a certain freshness. The cylinder which I intend for its consumption must be not a dead leaf but an enfeebled leaf, not entirely deprived of the juices with which the tree supplies it. I must wean my leaf and not kill it outright, so that, when dead, it will remain in its place during the few days of the grub’s extreme youth.’ The mother therefore, having made her selection, takes up her stand on the stalk of the leaf and there patiently inserts her rostrum, turning it with a persistency that denotes the great importance of this stiletto-thrust. A little wound opens, a fairly deep wound, which soon becomes a speck of decay. It is done: the conduits are cut and allow only a small quantity of sap to ooze into the edge. At the injured point the leaf yields under its own weight; it droops perpendicularly, becomes slightly withered and soon acquires the requisite flexibility. The moment has come for operating on it. That stiletto-thrust represents, though much less scientifically, the prick of the Hunting Wasp’s sting. [42] The latter wants for her offspring a prey now dead, now paralysed: she knows, with the thoroughness of a consummate anatomist, at what points it behoves her to insert her lancet to procure either sudden death or merely a suppression of movement. The Rhynchites requires for hers a leaf rendered flexible, half-alive, in a sense paralysed, which can be easily fashioned into a cylinder; she is perfectly familiar with the little leaf-stalk, the petiole, in which the vessels that disperse the energy of the foliage are gathered in a tiny bundle; and she inserts her drill here, here only and never elsewhere. Thus at one blow, without much trouble, she effects the ruin of the aqueduct. Where can the long-nosed insect have learnt her clever trick of draining springs? The leaf of the poplar is an irregular rhombus, a spear-head whose sides are expanded into pointed wings. The manufacture of the cylinder begins with one of these two lateral corners, the right or the left indifferently. Despite the hanging posture of the leaf, which makes the upper or lower surface equally easy of access, the insect never fails to take up its position on the upper side. It has its reasons, dictated by the laws of mechanics. The upper surface, which is smooth and more flexible, has to form the inside of the cylinder; the under surface, which has greater elasticity because of its powerful veins, has to occupy the outside. The statics of the small-brained Weevils agrees with that of the scientists.