The most remarkable feature, however, consists of two tiny craters, always open wide; two cunningly fashioned goblets which might have been wrought from a drop of red sealing-wax. [[157]]The sixth and seventh segments of the abdomen are the only ones that bear these vermilion goblets, placed in the middle of the back. I do not know the function of these little cups. Perhaps they should be regarded as organs of information, similar to the Pine Processionary’s dorsal mouths.
The Arbutus Caterpillar is much dreaded in the village. Woodcutters, faggot-binders, brushwood-gatherers, all are unanimous in reviling him. They have such a painfully vivid memory of the irritation that, when I listen to them, I can hardly repress a movement of the shoulders to relieve the imaginary itching in the middle of my back. I seem to feel the arbutus-faggot, laden with its glowing rags, rubbing my bare skin.
It is, it appears, a disagreeable job to cut down the shrub alive with caterpillars during the hottest part of the day and to shake, under the blows of the axe, that sort of upas-tree, shedding poison in its shade. As for me, I have no complaint to make of my relations with the ravager of the arbutus. I have very often handled him; I have applied his fur to the tips of my fingers, my neck and even my face, for hours at a time; I have ripped up [[158]]the nests to extract their populations for the purpose of my researches; but I have never been inconvenienced. Save in exceptional circumstances, the approach of the moult perhaps, this would need a skin less tough than mine.
The thin skin of a child does not enjoy the same immunity, as witness little Paul, who, having helped me to empty some nests and to collect the inhabitants with my forceps, was for hours scratching his neck, which was dotted with red wheals. My ingenuous assistant was proud of his sufferings in the cause of science, which resulted from heedlessness and also perhaps from bravado. In twenty-four hours, the trouble disappeared, without leaving any serious consequences.
All this hardly tallies with the painful experiences of which the woodcutters talk. Do they exaggerate? That is hardly credible; they are so unanimous. Then something must have been lacking in my experiments: the propitious moment apparently, the proper degree of maturity in the caterpillar, the high temperature which aggravates the poison.
To show itself in its full severity, the urtication demands the cooperation of certain undefined [[159]]circumstances; and this cooperation was wanting. Chance perhaps will one day teach me more than I want to know; I shall be attacked in the manner familiar to the woodcutters and shall pass a night in torment, tossing and turning as though on a bed of live coals.
What the direct contact of the caterpillar did not teach me the artifices of chemistry will demonstrate with a violence which I was far from expecting. I treat the caterpillar with ether, just as I treated the slough of the Pine Processionary. The number of the creatures taken for the infusion—they are pretty small as yet, are scarcely half the size which they will attain when mature—is about a hundred. After a couple of days’ maceration, I filter the liquid and leave it to evaporate freely. With the few drops that remain I soak a square of blotting-paper folded in four and apply it to the inner surface of my fore-arm, with a thin rubber sheet and a bandage. It is an exact repetition of what I did with the Pine Processionary.
Applied in the morning, the blister hardly takes effect until the following night. Then by degrees the irritation becomes unendurable; [[160]]and the burning sensation is so acute that I am tormented every moment with the desire to tear off the bandage. However, I hold out, but at the cost of a sleepless, feverish night.
How well I now understand what the woodcutters tell me! I had less than a square inch of skin subjected to the torture. What would it be if I had my back, shoulders, neck, face and arms tormented in this fashion? I pity you with all my heart, you labourers who are troubled by the hateful creature.
On the morrow, the infernal paper is removed. The skin is red and swollen, covered with tiny pimples whence ooze drops of serous fluid. For five days the itching persists, with a sharp, burning pain, and the running from the pimples continues. Then the dead skin dries and comes off in scabs. All is over, save the redness, which is still perceptible a month later.