“Let us turn now to a bird that builds upon piling. It is a warbler of large size, called the great sedge-warbler or river-thrush. It selects a cluster of four or five reeds that project above the surface of a pond, with their stalks rooted in the mud under the water and growing near together. These slender piles, the tops of which the bird brings into such proximity as may be desired and fastens with connecting strands, are made to bear an interlacing of flexible materials, such as rushes, bark-fibers, and long blades of grass. It is a basket-weaver’s job, with a framework of reeds as a basis for the structure. Finally, in this basket, which is made much longer than wide, is placed the nest proper, a warm little bed of cotton-like down, spiders’ webs, and wool. “But this abode resting on piles above the water is exposed to two dangers,—the swaying of the reeds which, bent over by the wind, might incline the nest so that it would spill its contents either of eggs or of young birds; and secondly, the spring freshets, which might rise so high as to submerge the nest. These dangers, however, have been foreseen by the bird. The nest is very deep, and furthermore the edges of the opening bend inward and form a parapet. In this way is avoided the risk of a fall when the reeds that bear the nest are swayed by the wind. Finally, since the sedge-warbler is at liberty to build her nest at any desired height above the surface of the pond, she places it always high enough to be beyond the reach of the rising water, even in great floods. One suspects the bird of being able to foresee, months in advance, the coming inundation; for she builds her nest at a greater or less elevation according to the high-water mark destined later to be reached by the surface of the pond. “The cisticola is a small warbler very common in the marshes of Camargue, at the mouth of the Rhone. Its nest is placed in the middle of a cluster of grass and rushes, and takes the form of a purse with a small round opening. Fine dry leaves form the bed on which the eggs rest, while other and larger leaves are fixed all around it to form an enclosure. “For this work the bird turns tailor, cutting the leaves and lapping them over one another. Along the border of each leaf it punches holes with the point of its beak and through these holes it passes one or more threads made of cobwebs and the down from certain plants. Its distaff for holding the thread—namely, the beak—does not admit of using very long strands; hence the needleful, so to speak, goes only twice or, at most, three times from one leaf to the next one. But no matter; the sewing is strong enough to fasten the whole into a sort of purse which keeps out the rain.