The second insect which I have observed for so long among the pines is the Bolboceras.  Its burrows, scattered here and there, higgledy-piggledy with those of the Minotaur, are easy to recognise.  The burrow of the Phalangist is surmounted by a voluminous rubbish-dump, the materials of which are piled in the form of a cylinder as long as the finger.  Each of these dumps is a load of refuse and rubbish pushed outward by the little sapper, which shoulders it up from below.  The orifice is closed whenever the insect is at home, enlarging its tunnel or peacefully enjoying the contents of its larder.

The lodging of the Bolboceras is open and surrounded simply by a mound of sand.  Its depth is not great; a foot or hardly more.  It descends vertically in an easily shifted soil.  It is therefore easy to inspect it, if we take care first of all to dig a trench so that the wall of the burrow may be afterwards cut away, slice by slice, with the blade of a knife.  The burrow is thus laid bare along its whole extent, from the surface to the bottom, until nothing remains of it but a demi-cylindrical groove.

Often the violated dwelling is empty.  The insect has departed in the night, having finished its business there.  It is a nomad, a night-walker, which leaves its dwelling without regret and easily acquires another.  Often, on the other hand, the insect will be found at the bottom of the burrow; sometimes a male, sometimes a female, but always alone.  The two sexes, equally zealous in excavating their burrows, work apart without collaboration.  This is no family mansion for the rearing of offspring; it is a temporary dwelling, made by each insect for its own benefit.

Sometimes the burrow contains nothing but the well-sinker surprised at its work:  sometimes—­and not rarely—­the hermit will be found embracing a small subterranean fungus, entire or partly consumed.  It presses it convulsively to its bosom and will not be parted from it.  This is the insect’s booty:  its worldly wealth.  Scattered crumbs inform us that we have surprised the beetle at a feast.

Let us deprive the insect of its booty.  We find a sort of irregular, rugged, purse-like object, varying in size from the largeness of a pea to that of a cherry.  The exterior is reddish, covered with fine warts, having an appearance not unlike shagreen; the interior, which has no communication with the exterior, is smooth and white.  The pores, ovoidal and diaphanous, are contained, in groups of eight, in long capsules.  From these characteristics we recognise an underground cryptogam, known to the botanists as Hydnocystis arenaria, and a relation of the truffle.