done by so quick and almost imperceptible a slight, that a person must have attended very exactly to their motions before he would be able to perceive it. As soon as the young are able to shift for themselves, the dams immediately turn their thoughts to the business of a second brood,* while the first flight, shaken off and rejected by their nurses, congregate in great flocks, and are the birds that are seen clustering and hovering on sunny mornings and evenings round towers and steeples, and on the roofs of churches and houses. These congregatings usually

* Mr. Hepburn also describes the entrance of a young brood into the world with great spirit. He had observed on the 19th of August that the young birds were fed nineteen times in the hour. One morning he observed the old birds dash up to the nest, then describing short curves in the air, repeating a note not to be misunderstood: he knew the young were about to take flight; one of them balanced itself on the edge of the nest, looked timidly into the yard, considered the risk for a minute or two, and allowed another to take its place. During all this time the parent birds kept diving about within a few feet of the nest, often fluttering within a few inches of the entrance, and endeavouring by many gestures to induce their charge to follow. The second bird, apparently distrusting its powers, retired also, and the first one again took its place, opening and shutting its wings; he at length summoned up all his resolution, sprung from his perch, and with self-taught pinions winnowed the air. He and his parents, now in ecstasies, returned to the window, and being joined by the other young bird, they sported about the tree-tops till seven o'clock, when they re-entered the nest. The next day the same sporting about occurred; but judgment had gone forth, their nest was pulled down. On their return one evening, each dashed into the corner of the window where it had been fixed, and wheeled back again in silent dismay; again they successively examined the place, shrieking their alarm note. They now darted wildly over the shrubbery, advancing again to examine it, their rage and alarm increasing. A dozen strange swallows now arrived, and joined the injured family in their outcries. After hovering about for an hour or two they disappeared, but frequented the fields for some days, when they disappeared for the season.--ED.

begin to take place about the first week in August; and therefore we may conclude that by that time the first flight is pretty well over. The young of this species do not quit their abodes all together; but the more forward birds get abroad some days before the rest. These approaching the eaves of buildings, and playing about before them, make people think that several old ones attend one nest. They are often capricious in fixing on a nesting-place, beginning many edifices, and leaving them unfinished; but when once a nest is completed in a sheltered place, it serves for several seasons. Those which breed in a ready-finished house get the start in hatching of those that build new by ten days or a fortnight. These industrious artificers are at their labours in the long days before four in the morning: when they fix their materials they plaster them on with their chins, moving their heads with a quick vibratory motion. They dip and wash as they fly sometimes in very hot weather, but not so frequently as swallows. It has been observed that martins usually build to a north-east or north-west aspect, that the heat of the sun may not crack and destroy their nests; but instances are also remembered where they bred for many years in vast abundance in a hot stifled inn-yard, against a wall facing to the south.

Birds in general are wise in their choice of situation but in this neighbourhood every summer is seen a strong proof to the contrary at an house without eaves in an exposed district, where some martins build year by year in the corners of the windows. But, as the corners of these windows (which face to the south-east and south-west) are

too shallow, the nests are washed down every hard rain; and yet these birds drudge on to no purpose from summer to summer, without changing their aspect or house. It is a piteous sight to see them labouring when half their nest is washed away, and bringing dirt "to patch the ruins of a fallen race" -"generis lapsi sarcire ruinas." Thus is instinct a most wonderful but unequal faculty; in some instances so much above reason, in other respects so far below it! Martins love to frequent towns, especially if there are great lakes and rivers at hand; nay, they even affect the close air of London. And I have not only seen them nesting in the Borough, but even in the Strand and Fleet-street; but then it was obvious from the dinginess of their aspect that their feathers partook of the filth of that sooty atmosphere. Martins are by far the least agile of the four species; their wings and tails are short, and therefore they are not capable of such surprising turns and quick and glancing evolutions as the swallow. Accordingly, they make use of a placid easy motion in a middle region of the air, seldom mounting to any great height, and never sweeping long together over the surface of the ground or water. They do not wander far for food, but affect sheltered districts, over some lake, or under some hanging wood, or in some hollow vale, especially in windy weather. They breed the latest of all the swallow kind: in 1772 they had nestlings on to October the twenty-first, and are never without unfledged young as late as Michael

mas.

As the summer declines the congregating flocks increase in numbers daily by the constant accession of the second broods, till at last they swarm in

myriads upon myriads round the villages on the Thames, darkening the face of the sky as they frequent the aits of that river, where they roost. They retire, the bulk of them I mean, in vast flocks together about the beginning of October; but have appeared of late years in a considerable flight in this neighbourhood, for one day or two, as late as November the third and sixth, after they were supposed to have been gone for more than a fortnight. They therefore withdraw with us the latest of any species. Unless these birds are very short-lived indeed, or unless they do not return to the district where they are bred, they must undergo vast devastations somehow, and somewhere; for the birds that return yearly bear no manner of proportion to the birds that retire.

House-martins are distinguished from their congeners by having their legs covered with soft, downy feathers down to their toes. They are no songsters; but twitter in a pretty inward soft manner in their nests. During the time of breeding they are often greatly molested with fleas.

SELBORNE, Nov. 20, 1773.

These numbers must have diminished immensely, since they are never observed now in such numbers in these localities. Boy sportsmen, and improved agriculture together, have greatly reduced the number of birds which formerly enlivened our rivers, groves, and green lanes.-ED.

RECEIVED your last favour just as I was setting out for this place; and am pleased to find that my monograph met with your approbation. My remarks are the result of many years observation; and are, I trust, true in the whole: though I do not pretend to say that they are perfectly void of mistake, or that a more nice observer might not make many additions, since subjects of this kind are inexhaustible.

If you think my letter worthy the notice of your respectable society, you are at liberty to lay it before them; and they will consider it, I hope, as it was intended, as an humble attempt to promote a more minute inquiry into natural history; into the life and conversation of animals. Perhaps hereafter I may be induced to take the house-swallow under consideration; and from that proceed to the rest of the British hirundines.

Though I have now travelled the Sussex-downs upwards of thirty years, I still investigate that chain of majestic mountains with fresh admiration year by year; and think I see new beauties every time I tra