What is it that they want? Food? I offer them some little bulbs with bundles of sprouting roots, a few bits of leaves and some fresh blades of grass. Nothing tempts them nor induces them to stand still. They appear to be selecting a favourable spot before descending underground. These hesitating explorations are superfluous on the soil which I have industriously prepared for them: the whole surface, so it seems to me, lends itself capitally to the work which I expect to see them accomplish. Apparently it is not enough. Under natural conditions, a preliminary run round may well be indispensable. There, sites as soft as my bed of heath-mould, purged of all hard bodies and finely sifted, are rare. There, on the other hand, coarse soils, on which the microscopic mattock can make no impression, are frequent. The grub has to roam at random, to walk about for some time before finding a suitable place. No doubt many even die, exhausted by their fruitless search. A journey of exploration, in a country a few inches across, forms part, therefore, of the young Cicada’s curriculum. In my glass jar, so sumptuously furnished, the pilgrimage is uncalled for. No matter: it has to be performed according to the time-honoured rites. My gadabouts at last grow calm. I see them attack the earth with the hooked mattocks of their fore-feet, digging into it and making the sort of excavation which the point of a thick needle would produce. Armed with a magnifying-glass, I watch them wielding their pick-axes, watch them raking an atom of earth to the surface. In a few minutes a well has been scooped out. The little creature goes down it, buries itself and is henceforth invisible. Next day I turn out the contents of the pot, without breaking the clod held together by the roots of the thyme and the wheat. I find all my larvæ at the bottom, stopped from going farther by the glass. In twenty-four hours they have traversed the entire thickness of the layer of earth, about four inches. They would have gone even lower but for the obstacle at the bottom. On their way they probably came across my thyme- and wheat-roots. Did they stop to take a little nourishment by driving in their suckers? It is hardly probable. A few of these rootlets are trailing at the bottom of the empty pot. Not one of my six prisoners is installed on them. Perhaps in overturning the glass I have shaken them off. It is clear that underground there can be no other food for them than the juice of the roots. Whether full-grown or in the larval stage, the Cicada lives on vegetables. As an adult, he drinks the sap of the branches; as a larva, he sucks the sap of the roots. But at what moment is the first sip taken? This I do not yet know. What goes before seems to tell us that the newly-hatched grub is in a greater hurry to reach the depths of the soil, sheltered from the coming colds of winter, than to loiter at the drinking-bars encountered on the way.