“Its nest is built sometimes in the fork of a high branch in a clump of bushes, and sometimes in the dense underwood of a thicket, a few feet from the ground; but it is most often attached to the trunk of a willow or a poplar tree. Its shape is that of a very large cocoon, and its entrance is at one side, about an inch from the top. On the outside it is made of lichens like those that cover the tree, in order to blend with the bark and deceive the eye of the passer-by. Fibers of wool serve to hold all the parts securely together. To make the dome of the nest rain-proof, it is formed of a sort of thick felt composed of bits of moss and cobwebs. The inside resembles an oven with cup-shaped bottom and very high top, and is furnished with a remarkably thick bed of downy feathers, whereon repose from sixteen to twenty little birds, arranged with careful order in the restricted space no larger, at the most, than the hollow of one’s hand. By what miracle of parsimonious economy do these twenty little ones with their mother manage to find room for themselves in this tiny abode? And how in the world can tails ever grow to such length there? “The nest of the swinging titmouse is still more remarkable. In our country this bird is hardly ever found except on the banks of the lower Rhone. It hangs its nest very high, on the tip-end of some swaying branch of a tree at the water-side, so that its brood is gently rocked by the breeze sweeping over the river.” “Why, I should think,” put in Emile, “there would be danger of the young birds’ spilling out of such a swinging nest.” “Not at all,” replied his uncle. “The shape of the nest provides against that. It is a sort of oval purse about as large as a wine-bottle, with a small opening at one side, near the top. This opening is prolonged like the neck of a bottle and will at the utmost admit one’s finger. To pass through so narrow an entrance, the titmouse, small as it is, must stretch the elastic wall, which yields a little and then contracts again. This purse, as I have called it, is made of the cotton-like flock that comes from the ripening seeds of poplars and willows in May. The titmouse gathers these bits of down and weaves them together with a woof of wool and hemp. The fabric thus obtained is not unlike the felt of a cheap hat. “It would be useless to seek an explanation of the bird’s astonishing success in manufacturing, with no implements but beak and claws, a textile that man’s skilful hand, left to its own resources, would be unable to produce; and this success the bird achieves with no previous apprenticeship, without hesitation and without ever having seen the thing done by others. At the very first trial the titmouse surpasses in its art our weavers and fullers.