Not the least strange of this assemblage is the author of our rainbow in the stump. My awkwardness had broken into a hollow which opened to the light on the other side of the rotten bole. A vine had tendriled its way into the crevice where the little weaver of rainbows had found board and lodging. We may call him toad-hopper or spittle-bug, or as Fabre says, "_Contentons-nous de Cicadelle, qui respecte le tympan._" Like all of its kindred, the Bubble Bug finds Nirvana in a sappy green stem. It has neither strong flight, nor sticky wax, thorny armature nor gas barrage, so it proceeds to fashion an armor of bubbles, a cuirass of liquid film. This, in brief, was the rainbow which caught my eye when I broke open the stump. Up to that moment no rainbow had existed, only a little light sifting through from the vine-clad side. But now a ray of sun shattered itself on the pile of bubbles, and sprayed itself out into a curved glory.
Bubble Bugs blow their froth only when immature, and their bodies are a distillery or home-brew of sorts. No matter what the color, or viscosity or chemical properties of sap, regardless of whether it flows in liana, shrub, or vine, yet the Bug's artesian product is clear, tasteless and wholly without the possibility of being blown into bubbles. When a large drop has collected, the tip of the abdomen encloses a retort of air, inserts this in the drop and forces it out. In some way an imponderable amount of oil or dissolved wax is extruded and mixed with the drop, an invisible shellac which toughens the bubble and gives it an astounding glutinous endurance. As long as the abdominal air-pump can be extended into the atmosphere, so long does the pile of bubbles grow until the insect is deep buried, and to penetrate this is as unpleasant an achievement for small marauders as to force a cobweb entanglement. I have draped a big pile of bubbles around the beak of an insect-eating bird, and watched it shake its head and wipe its beak in evident disgust at the clinging oily films. In the north we have the bits of fine white foam which we characteristically call frog-spittle, but these tropic relatives have bigger bellows and their covering is like the interfering mass of films which emerges from the soap-bubble bowl when a pipe is thrust beneath the surface and that delicious gurgling sound produced.
