After unsuspectingly passing a whole morning [[129]]with my insects, stooping over them, magnifying-glass in hand, to examine the working of their slits, I found my forehead and eyelids suffering with redness for twenty-four hours and afflicted with an itching even more painful and persistent than that produced by the sting of a nettle. On seeing me come down to dinner in this sad plight, with my eyes reddened and swollen and my face unrecognizable, the family anxiously enquired what had happened to me and were not reassured until I told them of my mishap.
I unhesitatingly attribute my painful experience to the red hairs ground to powder and collected into flakes. My breath sought them out in the open pockets and carried them to my face, which was very near. The unthinking intervention of my hands, which now and again sought to ease the discomfort, merely aggravated the ill by spreading the irritating dust.
No, the search for truth on the back of the Processionary is not all sunshine. It was only after a night’s rest that I found myself pretty well recovered, the incident having no further ill effects. Let us continue, however. [[130]]It is well to substitute premeditated experiments for chance facts.
The little pockets of which the dorsal slits form the entrance are encumbered, as I have said, with hairy refuse, either scattered or gathered into flakes. With the point of a paint-brush I collect, when they gape open, a little of their contents and rub it on my wrist or on the inside of my fore-arm.
I have not long to wait for the result. Soon the skin turns red and is covered with pale lenticular swellings, similar to those produced by a nettle-sting. Without being very sharp, the pain was extremely unpleasant. By the following day, itching, redness and lenticular swellings had all disappeared. This is the usual sequence of events; but let me not omit to say that the experiment does not always succeed. The efficacy of the fluffy dust appears subject to great variations.
There have been occasions when I have rubbed myself with the whole caterpillar, or with his cast skin, or with the broken hairs gathered on a paint-brush, without producing any unpleasant results. The irritant dust seems to vary in quality according to certain [[131]]circumstances which I have not been able to discover.
From my various tests it is evident that the discomfort is caused by the delicate hairs which the lips of the dorsal mouths, gaping and closing again, never cease grinding, to the detriment of their beards and moustaches. The edges of these slits, as their bristles rub off, furnish the stinging dust.
Having established this fact, let us proceed to more serious experiments. In the middle of March, when the Processionaries for the most part have migrated underground, I decide to open a few nests, as I wish to collect their last inhabitants for the purpose of my investigations. Without taking any precautions, my fingers tug at the silken dwelling, which is made of solid stuff; they tear it into shreds, search it through and through, turn it inside out and back again.
Once more and this time in a more serious fashion, I am the victim of my unthinking enthusiasm. Hardly is the operation completed, when the tips of my fingers begin to hurt in good earnest, especially in the more delicate part protected by the edge of the nail. The feeling is like the sharp pain of a sore [[132]]that is beginning to fester. All the rest of the day and all through the night, the pain persists, troublesome enough to rob me of my sleep. It does not quiet down until the following day, after twenty-four hours of petty torment.
How did this new misadventure befall me? I had not handled the caterpillars: indeed, there were very few of them in the nest at the time. I had come upon no shed skins, for the moults do not take place inside the silken purse. When the moment has come to doff the second costume, that of the red mosaic, the caterpillars cluster outside, on the dome of their dwelling, and there leave in a single heap their old clothes entangled with bits of silk. What is left to explain the unpleasant consequences to which the handling of the nest exposes us?