This habit of building in chimneys must have been acquired in a comparatively short time, for there were no chimneys in this country before the arrival of the white man, and for a long time afterward the settler had but one chimney in his house, which must have been used, at least for cooking purposes, in the summer. So perfect is this habit that the swallow looks and acts as though he were made for the chimney; his color is a sooty black, so that he does not tarnish his coat by rubbing against the chimney walls; the feathers of his tail end in hard spikes, that he can use them to prop himself against the wall. I have been interested on a summer evening watching these swallows in hundreds circling around a church chimney in Plattsburg, until finally the birds in the center began to enter the chimney, the circle growing smaller and smaller as they apparently poured down in the vortex of a whirlpool of swallows. Many birds have acquired a habit of associating with man, and we rarely find them, except during the season of their flight, far away from houses. The barn swallows always place their nests under the eaves or cornices of some building, usually a barn. These nests are built of mud gathered by the birds from wet places on the ground, and carried in their mouths to the sites chosen by them. Many of our farmers have an unkind feeling for the barn swallows, as they think the mud-daubed nests on the new red paint are not an artistic addition; but if our cattle could give an intelligent opinion they would welcome the birds, for all swallows are entirely insectivorous, and they must eat many flies and mosquitoes that otherwise would be left to torment our animals. Birds that build in inaccessible places seem to rely upon that for security, and apparently make little effort to conceal their nests, while those building on or near the ground are generally careful to hide them, and they display considerable cunning in preventing discovery. Robins, for instance, after the young are hatched, never drop the eggshells over the side of the nests to the ground, where they would attract attention and cause one to look directly overhead and thus find the nest, but take the broken shells in their bills and carry them off, dropping them while flying. Frequently birds are very shy and easily frightened away from their nests, but after they are well established they sometimes show a good deal of tenacity in staying by them until the young are ready to leave. Some years ago we opened an old ore mine, where a pair of phœbe birds had placed their nest on a shelf a few feet overhead, a projecting rock protecting it from the flying stones of the blasts that were fired several times a day, and the men were working so near that they could almost touch it with their hands. These birds did not desert their nests until the young were old enough to leave. The site was not used the following year, as is usually the case with the phœbe bird.