How is the sticky emission distributed over the whole body, both above and below? The larva is a legless cripple; it moves about by obtaining a hold with its behind. Moreover, it is well segmented. The back, in particular, has a series of fairly protuberant cushions; the ventral surface, on the other hand, is puckered by knotty excrescences, which change their shape considerably in the act of crawling. When moving, with the flexible fore-part of the body groping to find its way, the grub consists of a series of waves that follow one another in perfect order. Each wave starts from the hinder extremity and by swift degrees reaches the head. Straightway a second wave follows in the same direction, succeeded by a third, a fourth and so on, indefinitely. Each of these waves, proceeding from one end of the grub to the other, is a step. So long as the wave continues, the fulcrum, that is, the orifice of the intestine, remains in its place, at first a little before and then a little behind the movement as a whole. Hence the source of the sticky dew grazes first the tip of the abdomen and then the end of the back of the moving grub. In this way the tiny drop of gum is deposited above and below. The glue has still to be distributed. This is done by crawling. Between the puckers, the cushions, which the locomotory wave brings together and then separates, alternately come into contact and open clefts into which the sticky fluid gradually makes its way by capillary action. The grub clothes itself in glue without exercising any special skill, merely by moving along. Each locomotory wave, each step, supplies its quota to the viscous doublet. This makes up for the losses which the larva cannot fail to suffer on the road as it roams from pasture to pasture; and, since the fresh material balances the wastage of the old, a suitable coat is obtained, neither too thin nor too thick. The complete coating is rapidly effected. With the tip of a camel-hair pencil, I wash a grub in a little water. The viscosity dissolves and disappears; and the water used for washing the larva, evaporated on a slip of glass, leaves a mark like that of a weak solution of gum arabic. I place the grub to dry on blotting-paper. When I now touch it with a straw, it no longer sticks to it; it has lost its coating of varnish. How will it replace it? This is a very simple matter. I allow the grub to move about at will for a few minutes. No more is needed; the layer of gum is restored; the creature sticks to the straw that touches it. To sum up, the varnish with which the Cionus’ larva is covered, is a viscous fluid, soluble in water, quickly emitted and extremely slow to dry, even in an intensely hot sun and in the parching breath of the north-wind.