The unknown, that inexhaustible field which the future will cultivate, holds harvests in store for us beside which our present knowledge is but a pitiful gleaning. Under the sickle of science sheaves will one day fall whose grain to-day would seem a senseless paradox. Scientific illusions? Not so, if you please, but undeniable and positive realities, affirmed by the animal world, which in certain respects has a great advantage over the world of man.
In spite of his long professional practice, in spite of the aroma of the tuber which he [[307]]is seeking, the rabassier cannot guess the presence of the truffle, which ripens in winter underground, at a depth of eighteen inches or so; he needs the aid of the Dog or the Pig, whose scent pries into the secrets of the soil. Well, these secrets are known to different insects even better than to our two helpers. In order to discover the tuber on which their family of grubs is to be fed, they possess a scent of exceptional perfection.
Long ago, from truffles dug up spoilt and teeming with vermin and placed in this condition in a glass jar with a layer of fresh sand, I obtained first a small red Beetle (Anisotoma cinnamomea, Panz.) and then various Diptera, including a Sapromyzon, who, with her sluggish flight and feeble frame, reminds me of a Fly, clad in yellow velvet, known as Scatophaga scybalaria, that placid frequenter of human excrement in autumn.
The latter finds her truffle on the surface of the ground, at the foot of a wall or hedge, man’s usual hasty refuge in the country; but how does the other know at what point underground lies hers, or rather her grubs’ truffle? To go down and hunt about in the depths is beyond her power. Her frail [[308]]limbs, which the moving of a grain of sand would warp; her wings, which, if extended, would block her way through a gorge; her dress of stiff silk, militating against a smooth passage: these are all against her. The Sapromyzon is obliged to lay her eggs on the surface of the soil, but she must do so at the very spot beneath which the truffle lies, for the tiny grubs would die if they had to roam at random until they came upon their provender, which is always sparsely distributed.
The truffle-hunting Fly is therefore informed by her sense of smell of the spots favourable to her maternal plans; she possesses the scent of the rabassier Dog, indeed probably a better one, for she knows things by nature, having never been taught, whereas her rival has only received an artificial education.
It would be interesting to follow the Sapromyzon’s manœuvres, but the idea strikes me as impracticable. The insect is rare, flies away quickly and is soon out of sight. To observe it closely, to watch it at work would involve a great loss of time and a degree of assiduity of which I do not feel capable. Another discoverer of underground fungi shall [[309]]reveal what the Fly could hardly be expected to show us.
This is a pretty little black Beetle, with a pale and velvety belly, round as a cherry-stone and much the same size. The insect’s official title is Bolboceras gallicus, Muls. By rubbing the tip of its abdomen against the edge of its wing-cases it emits a soft chirrup similar to that of the little birds when their mother comes home with their food. The male wears a graceful horn on his head, copied on a smaller scale from that of the Spanish Copris.[5]
Deceived by this armour, I at first took the insect for a member of the Dung-beetles’ corporation and brought it up as such in captivity. I served it with these stercoral dainties which are most appreciated by its presumed colleagues. But never, no, never did it consent to touch them. Fie, for shame! Dung to a Bolboceras! Well! What on earth did I take him for? The epicure expects something very different. He wants not exactly the truffle of our banquets, but its equivalent. [[310]]
This characteristic was not displayed to me without patient investigation on my part. At the southern foot of the Sérignan hills, not far from the village, stands a thicket of maritime pines, alternating with rows of cypress-trees. Here, at the season of All Saints, after the autumnal rains, the mushrooms abound that frequent the Coniferæ, in particular the delicious milk-mushroom, which turns green at any part that is bruised and sheds tears of blood when you break it.[6] In the mild days of autumn this is the favourite walk of my household, being far enough to exercise young legs and near enough not to tire them.
They find everything there: old Magpies’ nests, formed of bundles of twigs; Jays squabbling with one another, after filling their crops with acorns on the oaks hard by; Rabbits suddenly starting out of a rosemary-bush, showing their little white upturned scuts; Geotrupes[7] hoarding away food for the winter and heaping up their rubbish on the [[311]]threshold of the burrow. And then lovely sand, soft to the touch, easy to dig into tunnels, easy to build into rows of huts which we thatch with moss and surmount with a bit of reed by way of a chimney; and the delicious lunch off an apple to the sound of the Æolian harps softly sighing through the pine-needles!