[page] 324

"Worms.—Every one must have observed the little heaps of stones which are almost always to be seen on garden walks or wherever there is loose gravel. Each of these heaps will be found to surround and cover the hole of an earthworm. Nothing seems to come amiss with earthworms; they will take sticks, paper, bits of slate, anything in short that they can find within reach. Being curious to know how they manage to collect these stones (often of considerable size), in spring, a year or two ago I removed several little mounds, leaving a clear space of several inches round the holes, and in the evening went out with a light to watch. Worms rarely show themselves till evening, and then they always keep their tails fixed in their holes, while feeling around with their heads. One of them, thus lying half out of its hole, soon fastened its mouth on to a stone (about the size of the end of one's thumb) and proceeded to drag it, apparently by the force of sucition quickly back to its hole. This I have since seen repeated several times with small stones, the worm's tail being always kept firmly anchored in the ground. Their strength is surprising. On one occasion I found stone weighing two ounces drawn over one of the clean cleared holes, and another weighing one ounce. After two nights some of the holes had eight or nine small stones over them; after four nights one had about 30, another 24 stones. What their object can be in taking all this trouble, and thus covering up their holes, I cannot imagine. Can any of your readers throw any light on the subject? I. W.¹

¹ A letter from Darwin to the editor of the Gardeners' Chronicle Maxwell Tylden Masters, 21 March [1868], Correspondence vol. 16, p. 290, shows that Darwin sent this "little communication" to the Gardeners' Chronicle. The editors of the Correspondence note: "CD's copy (in the Cory Library, Cambridge University Botanic Garden) has the annotation 'Lucy | Worms' at the top of the first page of the issue, and the article is annotated." The note is attributed to Lucy Caroline Wedgwood (1846-1919), fourth child of Josiah Wedgwood III and Darwin's niece.

Darwin referred to Wedgwood's observations in Earthworms, pp. 60-1.