That the wren should use such coarse, refractory materials, especially since it builds in holes where twigs are so awkward to carry and adjust, is curious enough. All its congeners, the marsh wrens, the Carolina wren, the winter wren, build of soft flexible materials. The nest of the winter wren, and of the English "Jenny Wren," is mainly of moss, and is a marvel of softness and warmth.
One day a swarm of honey-bees went into my chimney, and I mounted the stack to see into which flue they had gone. As I craned my neck above the sooty vent, with the bees humming about my ears, the first thing my eye rested upon in the black interior was two long white pearls upon a little shelf of twigs, the nest of the chimney swallow, or swift,--honey, soot, and birds' eggs closely associated. The bees, though in an unused flue, soon found the gas of anthracite that hovered about the top of the chimney too much for them, and they left. But the swallows are not repelled by smoke. They seem to have entirely abandoned their former nesting-places in hollow trees and stumps and to frequent only chimneys. A tireless bird, never perching, all day upon the wing, and probably capable of flying one thousand miles in twenty-four hours, they do not even stop to gather materials for their nests, but snap off the small dry twigs from the treetops as they fly by. Confine one of these swallows to a room and it will not perch, but after flying till it becomes bewildered and exhausted, it clings to the side of the wall till it dies. I once found one in my room on returning, after several days' absence, in which life seemed nearly extinct; its feet grasped my finger as I removed it from the wall, but its eyes closed, and it seemed about on the point of joining its companion which lay dead upon the floor. Tossing it into the air, however, seemed to awaken its wonderful powers of flight, and away it went straight toward the clouds. On the wing the chimney swallow looks like an athlete stripped for the race. There is the least appearance of quill and plumage of any of our birds, and, with all its speed and marvelous evolutions, the effect of its flight is stiff and wiry. There appears to be but one joint in the wing, and that next the body. This peculiar inflexible motion of the wings, as if they were little sickles of sheet iron, seems to be owing to the length and development of the primary quills and the smallness of the secondary. The wing appears to hinge only at the wrist. The barn swallow lines its rude masonry with feathers, but the swift begins life on bare twigs, glued together by a glue of home manufacture as adhesive as Spaulding's.