ALL birds that take their food while on the wing, and seldom or not much in any other way, may be arbitrarily designated as Birds of the Air, whether their prey inhabit the air, like the insects taken by the Swallows and Flycatchers, or the cup of a flower, like those taken by the Humming-Bird. Of these the Swallows, including the Martin and the Swift, are the most conspicuous and most numerous in this part of the world. These birds have large wings, fly very swiftly, and without a great deal of apparent motion of their wings. It could hardly be explained on mechanical principles how they are able to pass through the air with such rapidity. While watching them on the wing, it seems as if they were never weary; but Daines Barrington says the Swallow makes frequent pauses for rest while engaged in the pursuit of insects.

THE BARN-SWALLOW.

This is the species with which the inhabitants of New England are best acquainted. But they are every year becoming fewer, and this diminution of their numbers is attributed by Mr. S. P. Fowler to our modern tight barns. Though they often build under the eaves of houses and in sheds, they find in these places but limited accommodations, compared with the old-fashioned barns that were formerly scattered over the whole country. There are now hundreds only where thirty years ago there were

thousands, all swarming with these lively birds, who built their nests on the horizontal beams that supported the barn roof. The birds left us when they were deprived of their tenements, while the Cliff-Swallow, that builds under the eaves of barns and houses and under projecting cliffs of rocks, has increased, feeding upon the larger quantity of insects consequent upon the absence of the Barn-Swallow.

This species is of a social habit; fond of building and breeding, as it were, in small communities. An oldfashioned barn has been known to contain as many as two dozen nests. They are constructed of materials similar to those of a Robin's nest; but the Swallow adds to the lining of grass a few feathers, which the Robin does. not use. Dr. Brewer alludes to a custom among the BarnSwallows of building "an extra platform against, but distinct from the nest itself, designed as a roosting-place for the parents, used by one during incubation at night or when not engaged in procuring food, and by both when the young are large enough to occupy the whole nest." The eggs of the Barn-Swallow are nearly white, with a fine sprinkling of purple. Two broods are reared in a season. When the bird appears to have a third brood I think it must have happened from the accidental destruction of the second brood of eggs.

THE CLIFF-SWALLOW.

The Cliff-Swallow is the species that has apparently filled the vacancy made by the diminished numbers of the Barn-Swallow. It is a smaller bird and more whitish underneath. The nests of this species are placed under the eaves of houses, sometimes extending nearly across the whole side of a roof, resembling in some degree a long row of hornets' nests. The nest is of a roundish

shape; the body of it is plastered to the wood; the entrance is the neck, slightly covered for protection from rain. They are made of clay and mud without intermixture of other substances. They are lined with grass and feathers.

This species was at the early settlement of the country so rare, in this part of the continent, that it escaped the notice of some of the earliest observers of the habits of our birds. It was not known even to Alexander Wilson. It seems to have been observed and described in Maine before it was well known in any of the other States. Dr. Brewer says of this species: "I first observed a large colony of them in Attleborough (Mass.) in 1842. Its size indicated the existence of these birds in that place for several years. The same year they also appeared in Boston, Hingham, and in other places in the neighborhood." The notes of this Swallow are not so agreeable as those of the Barn-Swallow and other species.

THE WOOD-SWALLOW.

The White-bellied Swallow is known in the British Provinces by the name of "Wood-Swallow." This will be regarded a very appropriate designation, when we consider the continuance of the primitive habits of this bird of building in hollow trees. Samuels has seen great numbers of the nests of this species in the woods of Maine, near the northern lakes, built in hollow trees, some of them standing in water. In an area of about ten rods he counted fifty nests. He says this species is the most common of the Swallows in that region. The nests are formed entirely of grass and feathers without any mud, for which there is no necessity. The eggs are pure white.

This species has superseded the Purple Martin in many

parts of New England, as the Cliff-Swallow has superseded the Barn-Swallow. They are pretty generally distributed over the whole continent, though, notwithstanding the primitive habits that still adhere to a great part of their numbers, they are most numerous in cities and their suburbs, attracted probably by the vast multitudes of small flies, which are more abundant than in the woods. The Cliff-Swallow breeds as far as the Arctic Seas.

THE SAND-MARTIN.

This is not the least interesting of the family of Swal lows. The swarming multitudes that often assemble in one vicinity, their constant motions while going in and out their holes in the sand-bank, and sailing about on rapid wing in quest of their microscopic prey, and their lively notes render them objects of frequent attention. Of all the Swallows the Sand-Martins afford the most amusement for small boys in the vicinity, who employ themselves in digging out their nests, which are sometimes less than two feet under the surface. The difficulty is in finding the exact spot where the excavation should be made. Large multitudes of them formerly assembled every year and made their holes in the high sand-bluffs that surround the Beverly coast. I have counted over fifty holes in one large and high bank.

"The work of preparation," says Dr. Brewer, "they perform with their closed bill, swaying the body round on the feet, beginning at the centre and working outwards. This long and often winding gallery gradually expands into a small spherical apartment, on the floor of which they form a rude nest of straw and feathers. The time occupied in making these excavations varies greatly with the nature of the soil, from four or five days to twice that number."