This activity at the outset, which is everywhere the same, in media differing so greatly in aroma and flavour, would lead us to suppose, at first thoughts, that the young Cerambyx is endowed with a highly complaisant stomach and can feed on the fig-tree, oozing with acrid milk, the laurel, aromatic with essential oils, and the pine, saturated with resin, as well as on the oak, seasoned with tannin. Reflection persuades us that we are mistaken. The little creature is not engaged in eating: it is toiling to make itself a deep lodging in which it can feast in peace. When examined through the lens, the sawdust confirms our theory: this dust has not passed through the digestive canal; it has played no part in feeding the grub. It is only so much meal, crumbled by the mandibles, and nothing more. When appetite has come and the requisite depth has been reached, the grub at last begins to eat. If it finds the traditional food ready to its teeth, the sap-wood of the oak, with its astringent flavour, it gorges itself and proceeds to digest. If it finds nothing of the sort, it abstains from eating. This is certainly the reason why the heap of sawdust grows larger on the billet of oak but remains indefinitely stationary on the others. What do they do in their little galleries, these grubs subjected to a strict fast in the absence of suitable victuals? In March, six months after the hatching, I look into the matter. I split the billets. There they are, the little grubs, no larger, but still lively, swaying their heads to and fro if I disturb them. This persistence of life in such puny creatures deprived of food rouses our astonishment. It reminds us of the grubs of the Attelabus-beetle, which, subjected to the drought of summer in their little kegs made of a strip of oak-leaf, cease eating and slumber, half-dead, for four or five months, until the autumn rains have softened their food. When I myself produced rain, a thing not beyond my power, so far as the needs of a grub are concerned, when I softened the rigid kegs and made them edible by a brief immersion in water, the recluses used to return to life, begin to eat again and continue their larval development without further check. Similarly, after six months’ fasting in the heart of inacceptable sticks, the Capricorn grubs would have recovered their strength and activity if I had removed them and put before them a freshly-cut billet of oak. I did not do it, so certain did the success of the experiment appear. I had other schemes in view. I wished to learn how long this arrested life could be prolonged. A year after the hatching, I examined my specimens again. This time I have gone too far. All the grubs are dead, reduced to dark brown granules; only those in the oak are alive and already well-grown. The experiment is conclusive; the Great Capricorn has the oak for her domain; any other tree is fatal to her grub.