I take out a few larvæ which are already fairly well-grown and install dwellings and dwellers in glass tubes. For a long time, with my pocket-lens, I watch the prisoners. I cannot see that they bite into the central knob, which is already damaged, nor the axis, which also has been cut into. From these surfaces, which have been scored since I know not how long; from what appeared to be their daily bread, their mandibles remove not the smallest particle. At most the mouth is applied for a moment to the surface; then it is withdrawn, uneasy and disdainful. It is evident that the ligneous fare, though still quite fresh, does not suit. The proof is completed by the final result of my experiments. In vain I keep the thistle-heads fresh in glass tubes, plugged with a stopper of wet cotton-wool: my attempts at rearing are not once crowned with success. As soon as the head is removed from the plant, its inhabitants begin to die of starvation, whether I intervene or whether I do not. They all pine away in the heart of their native globe and at last perish, no matter in what receptacle—test-tube, flask or tin box—I place my collection. Later, on the other hand, when the feeding-period is over, I shall find it very easy to keep the grubs in good condition and to follow at will their preparations for the nymphosis. This failure tells me that the larva of the Spotted Larinus does not sustain itself with solid food; it prefers the clear broth of the sap. It taps the cask of its azure cellar, that is to say, it makes a careful gash in the axis of the head as well as in the central nucleus. From these surface wounds, which are kept open by fresh strokes of the plane as soon as a dry scab forms upon them, it laps the sap of the thistle, which oozes up from the roots. As long as the blue globe is on its stalk, very much alive, the sap ascends, the broached casks exude their contents and the grub sips the nourishing draught. But, once detached from the stem, cut off from its source of supply, the cellar runs dry. Thereupon the larva promptly dies. This explains the fatal catastrophe of my attempts to rear it. All that the Larinus-larvæ need is to lick the exudations from a wound. The method employed is henceforth obvious. The new-born grubs, hatched upon the central globe, take their places around its axis, proportioning the distance between them to the number of guests. Each of them peels and slashes with its mandibles the part in front of it, causing the nutritious moisture to exude. If the spring dries up through healing, fresh bites revive it.