The Zeuzera, or Leopard-moth, a large and beautiful white Moth with blue spots, is more general. She is the scourge of most of the trees and shrubs in my enclosure. I find her caterpillar chiefly in the lilac-tree; also in the elm, the plant-tree, the quince, the guelder-rose, the pear-tree and the chestnut. In these, always working upwards, it bores itself straight galleries which turn a branch the thickness of a good-sized bottle-neck into a fragile sheath soon broken by the winter wind. To return to the specialists: the Shagreen Saperda exploits the black poplar and accepts nothing else, not even the white poplar; the Spotted Saperda has the elm for its domain; the Scalary Saperda is faithful to the dead cherry-tree. [71] The Great Capricorn lodges her grubs in the oak, sometimes the English oak and sometimes the evergreen oak, or ilex. This last Beetle, being easily reared with slices of pear for food and sticks of wood in which to establish her family, lends herself to an experiment of some interest. I collect the eggs which the mother’s pointed, groping oviduct has slipped into the irregular crevices of the bark. The number obtained enables me to make a variety of tests. Will the new-born larvæ accept the first wood that offers after they are hatched. That is the problem. I select freshly-cut billets measuring two or three fingers’-breadths in diameter. They include the ilex, elm, lime, robinia, cherry, willow, elder, lilac, fig, laurel and pine. To avoid falls, which would confuse the new-born grubs if they had to wander about in search of the spot at which to bore, I do my best to imitate the natural conditions. The mother Capricorn lodges her eggs, one at a time, here and there in the fissures of the bark, fixing them with a thin varnish. I cannot gum the eggs in this way: my glue would perhaps endanger the vitality of the egg; but I can resort to the firm support of a furrow. With the point of a penknife I make this furrow, that is to say, a tiny cleft into which the egg sinks half-way. This precaution succeeds admirably. In a few days the eggs hatch without falling off, each at the spot decided by the point of my penknife. I watch in amazement the first wriggles of the feeble little creature’s body, the first strokes of its plane, as it attacks the thankless material, the bark and the wood, still dragging its white egg-shell behind it. By the following day, each grub has disappeared beneath a fine sawdust, the result of the work accomplished. The mound is still very small, matching the weakness of the excavator. Let us leave the grub at work. For a fortnight we see the mound grow bigger and bigger, until it is almost the size of a pinch of snuff. Then everything stops. The amount of sawdust does not increase, except in the oak-billet.