It is better than a lining; it is a precious store of putty. When the grub wants to repair its shell or to enlarge it to fit its figure, which increases daily, it proceeds to clean out its cess-pool. It turns round and, with the tips of its mandibles, collects singly, from the back, the brown pellets which it has only to work up with a little earth to make a ceramic paste of the highest quality. Observe also that the grub's pottery is shaped like the legs of our peg-top trousers and is wider inside than at the opening. This excessive girth has its obvious use. It enables the animal to bend and turn when the contents of the cess-pit are needed for a fresh course of masonry. A garment should be neither too short nor too tight. It is not enough to add a piece which lengthens it as the body grows longer; we must also see that it has sufficient fulness not to hamper the wearer and to give him liberty of movement. The Snail and all the molluscs with turbinate shells increase the diameter of their corkscrew staircase by degrees, so that the last whorl is always an exact measure of their actual condition. The lower whorls, those of childhood, when they become too narrow, are not abandoned, it is true; they become lumber-rooms in which the organs of least importance to active life find shelter, drawn out into a slender appendage. The essential portion of the animal is lodged in the upper story, which increases in capacity. The big Broken Bulimus, that lover of crumbling walls and limestone rocks leaning in the sun, sacrifices the graces of symmetry to utility. When the lower spirals are no longer wide enough, he abandons them altogether and moves higher up, into the spacious staircase of recent formation. He closes the occupied part with a stout partition-wall at the back; then, dashing against the sharp stones, he chips off the superfluous portion, the hovel not fit to live in. The broken shell loses its accurate form in the process, but gains in lightness. The Clythra does not employ the Bulimus' method. It also disdains that of our dressmakers, who split the overtight garment and let in a piece of suitable width between the edges of the opening. To break the jar when it becomes too small would be a wilful waste of material; to split it lengthwise and increase its capacity by inserting a strip would be an imprudent expedient, which would expose the occupant to danger during the slow work of repair. The hermit of the jar can do better than that. It knows how to enlarge its gown while leaving it, except for its fulness, as it was before.