The swallow breeds twice a year, and constructs its nest of mud or clay, mixed with hair and straw; the clay is tempered with the saliva of the bird, (with which nature has supplied it,) in order to make it tenacious and easily moulded. The shell or crust of the nest, thus composed, is lined with fine grass or feathers, firmly fixed against the rafters of barns or out-houses. The writer has heard of a pair that yearly built in the rafters of a wheelwright’s shop, undisturbed by the din of the hammer or the grating of the saw. The propensity which these birds, in common with their family, exhibit to return to the same spot, and to build in the same barn year after year, is one of the most curious parts of their history. During their sojourn in foreign climes, they forget not their old home, the spot where they were bred, the spot where they have reared their offspring; but, as soon as their instinct warns them to retrace their pilgrimage, back they hasten, and, as experiments have repeatedly proved, the identical pair that built last summer in the barn, again take up their old quarters, passing in and out by the same opening. It is delightful to witness the care which the swallow manifests towards her brood. When able to leave the nest, she leads them to the ridge of the barn, where, settled in a row, and as yet unable to fly, she feeds them with great assiduity. In a day or two they become capable of flight, and then they follow their parents in all their evolutions, and are fed by them while on the wing. In a short time they commence an independent career, and set up for themselves. The notes of the swallow, though hurried and twittering, are very pleasing; and the more so as they are associated in our minds with ideas of spring, and calm serenity, and rural pleasures. The time in which the bird pours forth its melody is chiefly at sunrise, when, in “token of a goodly day,” his rays are bright and warm. “The breezy call of incense-breathing morn, The swallow, twittering from the straw-built shed,” unite alike to call man from his couch of rest, and to praise “the God of seasons as they roll.” After the work of rearing the young, ere autumn sears the leaf, the swallow prepares to depart. Multitudes, from various quarters, now congregate together, and perch at night in clusters on barns or the branches of trees, but especially among the reeds of marshes and fens, round which they may be observed wheeling and sinking and rising again, all the time twittering vociferously, before they finally settle. It was from this circumstance that some of the older naturalists supposed the swallow to become torpid and remain submerged beneath the water during winter, and to issue forth from its liquid tenement on the return of spring; a theory utterly incompatible with reason and facts, and now universally discarded. The great body of these birds depart about the end of September.