I shall consult the Terebinth-lice by preference. They are near neighbours of mine, a condition essential to frequent visits; they practise an industry, which is a not uninteresting addition; and they are crowded into sealed enclosures where we can follow the progress of the family without too much confusion. [[243]]
The shrub that feeds them, the terebinth, or turpentine-tree, abounds on the Sérignan hills. It is sensitive to the cold, a lover of stony wastes scorched by the sun. Its insignificant flowers are succeeded by pretty bunches of little berries, first pink, then blue, smelling of turpentine and beloved by the Redstart when migrating in autumn.
Any one seeing it for the first time, unless conversant with its history, might think that it bore yet another crop of fruit, quite different from that of the berries. On the tips of the boughs, singly or in bunches, are certain twisted horns, a fairly good imitation of certain pimentos, if the coral-red of maturity were replaced by a straw-yellow washed with rose. What is more, mimic apricots, fresher and more satiny than those of our orchards, are seen hanging from the leaves. Tempted by appearances, we open these deceptive productions. Horror! The contents consist of myriads of Lice, swarming about in the midst of a floury dust.
Pilgrims to the Holy Land tell us that on certain bushes in the neighbourhood of Sodom beautiful-looking apples may be gathered, which are full of ashes within. The [[244]]pretty apricots and cornute pimentos of the terebinth-tree are the apples of Sodom, the Dead Sea fruit. Beneath an attractive exterior, they too contain nothing but ashes, live ashes, a wriggling whirl of dusty vermin. These are excrescences, galls, in which the opulent family of the Plant-lice lives isolated from the outer world.
To follow the progress of these strange productions I needed a terebinth which I could inspect often and in comfort. I happen to have one a few steps from my door. When I was stocking the enclosure with a certain amount of woody vegetation, I conceived the happy thought of planting a terebinth. A profitable tree, yielding acceptable fruit, would have died in this ungrateful soil; but this, which is good for nothing but firewood, is prospering excellently. It has grown into a magnificent specimen; and year after year it never fails to be covered with galls. So here I am, the fortunate possessor of a tree full of Lice. Let us call it by its Provençal name: lou Petelin, or lou Pesouious, the lousy one.
Scarcely a day passes but I give it a glance, attracted as I am by the daily happenings in [[245]]the enclosure. Let us examine it closely. The “lousy one” has its merits: it is the depository of interesting secrets. In winter it is bare. With the foliage the wigwams of Lice have disappeared, though towards the end of the summer they were weighing it down with their numbers. Nothing is left but the horn-shaped shells, now black and dilapidated ruins.
What has become of the vast population of the bush? How will it recover possession of its terebinth? In vain I inspect the bark of the trunk and branches and twigs: I see nothing capable of explaining the coming invasion. Nowhere are there any lice in a state of lethargy, nowhere any eggs awaiting the spring hatching. Nor are there any in the neighbourhood, nor, in particular, in the heap of dead leaves rotting at the foot of the tree. Yet the tiny creature cannot come from a distance: a mere atom, as I see it in imagination, does not go wandering across country. It is certainly on the tree that feeds it; but where?
One day in January, weary of my futile search, it occurs to me to strip off, in shreds, a lichen, the Wall Parmelia, which here [[246]]and there carpets thinly with its yellow rosettes the base and the thicker branches of my terebinth. I examine my harvest through the lens, in my study. What is this?
A magnificent discovery! In my scrap of lichen, no larger than a finger-nail, I discover a world. On the inner surface, in the winding crevices between the scales, are encrusted vast numbers of tiny red bodies barely a millimetre[1] in length. Some of them are entire and oval in shape; some, truncated and empty, display open pouches with pointed ends. All are plainly segmented.
Can it be that I have before my eyes the Louse’s eggs, of which some are old and empty, while others are recent and contain their germ? This idea is soon disposed of: an egg has not this segmentation like that of an insect’s abdomen. Here is a more significant fact: a head and antennæ are visible in front, while legs may be seen underneath; the whole is dry and brittle. These specks, accordingly, once lived and walked. Are they dead now? No, for when I crush them with the point of a needle traces of [[247]]moisture gush forth, a sign of a living organism. Only the shell is dead.