The pewees, as a class, are the best architects we have. The king-bird builds a nest altogether admirable, using various soft cotton and woolen substances, and sparing neither time nor material to make it substantial and warm. The green-crested pewee builds its nest in many instances wholly of the blossoms of the white-oak. The wood-pewee builds a neat, compact, socket-shaped nest of moss and lichens on a horizontal branch. There is never a loose end or shred about it. The sitting bird is largely visible above the rim. She moves her head freely about and seems entirely at her ease,--a circumstance which I have never observed in any other species. The nest of the great-crested fly-catcher is seldom free from snake skins, three or four being sometimes woven into it. About the thinnest, shallowest nest, for its situation, that can be found is that of the turtle-dove. A few sticks and straws are carelessly thrown together, hardly sufficient to prevent the eggs from falling through or rolling off. The nest of the passenger-pigeon is equally hasty and insufficient, and the squabs often fall to the ground and perish. The other extreme among our common birds is furnished by the ferruginous thrush, which collects together a mass of material that would fill a half-bushel measure; or by the fish-hawk, which adds to and repairs its nest year after year, till the whole would make a cart-load. The rarest of all nests is that of the eagle, because the eagle is the rarest of all birds. Indeed so seldom is the eagle seen that its presence always seems accidental. It appears as if merely pausing on the way, while bound for some distant unknown region. One September, while a youth, I saw the ring-tailed eagle, an immense, dusky bird, the sight of which filled me with awe. It lingered about the hills for two days. Some young cattle, a two-year-old colt, and half a dozen sheep were at pasture on a high ridge that led up to the mountain, and in plain view of the house. On the second day this dusky monarch was seen flying about above them. Presently he began to hover over them, after the manner of a hawk watching for mice. He then with extended legs let himself slowly down upon them, actually grappling the backs of the young cattle, and frightening the creatures so that they rushed about the field in great consternation; and finally, as he grew bolder and more frequent in his descents, the whole herd broke over the fence and came tearing down to the house "like mad." It did not seem to be an assault with intent to kill, but was perhaps a stratagem resorted to in order to separate the herd and expose the lambs, which hugged the cattle very closely. When he occasionally alighted upon the oaks that stood near, the branch could be seen to sway and bend beneath him. Finally, as a rifleman started out in pursuit of him, he launched into the air, set his wings, and sailed away southward. A few years afterward, in January, another eagle passed through the same locality,