In the middle of August, when the larva, having achieved its full growth, is busy strengthening and plastering its abode in view of the approaching nymphosis, I half-open a few cells. The hulls opened, but still adhering to the natal blossom, are arranged in a row in a glass tube which will enable me to watch the work without disturbing the worker. I have not long to wait for the result. In a state of repose, the grub is a hook with the extremities very near together. From time to time I see it bring the two ends into intimate contact and close the circuit. Then—do not let us be shocked by the grub’s procedure: this would mean misconceiving life’s sacred simplicities—then with its mandibles it very neatly gathers from the stercoral orifice a tiny drop the size of an ordinary pin’s head. It is a muddy white liquid, flowing like gum, similar in appearance to the resinous beads that ooze from the horned galls of the turpentine-tree when you break them. The grub spreads its little drop over the edges of the breach made in its dwelling; it distributes it here and there, very sparingly; it pushes and coaxes it into the gaps. Then, attacking the adjacent florets, it picks out the shreds and chips and bits of hairs. This does not satisfy it. It rasps the axis and the central nucleus of the blossom, detaching tiny scraps and atoms. A laborious task, for the mandibles are short and cut badly. They tear rather than slice. All this is distributed over the still fresh cement. This done, the grub bestirs itself most strenuously, bending into a hook and straightening out again; it rolls and glides about its cabin to make the materials amalgamate and to smooth the wall with the pad of its round rump. When this pressing and polishing is finished, the larva once more curves into a circle. A second white drop appears at the factory-door. The mandibles take hold of the ignominious product as they would of an ordinary mouthful; and the process is repeated as before: the cell is first smeared with glue and then encrusted with ligneous particles. After thus expending a certain number of trowelfuls of cement, the grub remains motionless; it seems to be abandoning a job too much for its means. Twenty-four hours later, the open hulls are still gaping. An attempt has been made to repair the cell, but not to close it thoroughly. The task is too heavy. What is lacking? Not the ligneous materials, which can always be obtained from the grub’s surroundings, but the adhesive cement, the factory having closed down. And why has it closed down? The answer is quite simple: because the vessels of the thistle-head detached from its stalk are dry and can no longer furnish the food upon which everything depends.