The Rhynchites usually works backwards. When her line is finished, she is careful not to abandon the fold which she has just made and return to the starting-point to begin another. The part last folded is not yet fastened sufficiently; if left to itself too soon, it might easily rebel and flatten out again. The insect, therefore, persists at this extreme point, which is more exposed than the rest; and then, without letting go, makes her way backwards to the other end, still with patient slowness. In this way, an added firmness is imparted to the fold; and the next fold is prepared. At the end of the line there is a fresh prolonged halt, followed by a fresh backward motion. Even so does the husbandman’s plough-share alternate its work on the furrows. Less frequently, when, no doubt, the leaf is found to be so limp as to entail no risk, the insect abandons the fold which it has just made, without going over it again in the opposite direction, and quickly scrambles to the starting-point to contrive a new one. There we are at last. Coming and going from top to bottom and from bottom to top, the insect, by dint of stubborn dexterity, has rolled its leaf. It is now on the extreme edge of the border, at the lateral corner opposite to that whereat the work commenced. This is the keystone upon which the stability of the rest depends. The Rhynchites redoubles her cares and patience. With the end of her rostrum, expanded spatulawise, she presses, at one point after the other, the edge to be fixed, even as the tailor presses the recalcitrant edges of a seam with his iron. For a long, a very long time, without moving, she pushes and pushes, awaiting the proper adhesion. Point by point, the whole of the corner welt is fastidiously sealed. How is adhesion obtained? If only some thread or other were brought into play, one would readily look upon the rostrum as a sewing-machine planting its needle perpendicularly into the stuff. But the comparison is not allowable: there is no filament employed in the work. The explanation of the adherence lies elsewhere. The leaf is young, we said; the fine pads of its denticulations are glands whence ooze liquid beads of glue. These drops of viscous matter are the gum, the sealing-wax. With the pressure of its beak, the insect makes it gush more plentifully from the glands. It then has only to hold the signet in position and wait for the impress to acquire consistency. Taken all round, it is our method of sealing a letter. If it hold ever so little, the leaf, losing its elasticity gradually as it withers, will soon cease to fly back and will of itself retain the scroll-form imposed upon it.