The swift arrives in this country about the end of April or early in May, and from that time onwards, throughout the spring and summer months, day after day, from morning until evening, he may be seen overhead, in twos, threes, and half-dozens, pursuing his mad, everlasting race through the air. Even as late as ten o’clock in the evening, or later, when his form can no longer be followed by the straining sight, his shrill, exulting cry may be heard at intervals, now far off, and now close at hand, showing that the daylight hours of these northern latitudes are not long enough to exhaust his wonderful energy. It has even been supposed by some naturalists that, when not incubating, he spends the entire night on the wing. This is hard to believe; but if we consider his rate of speed, and the number of hours he visibly spends on the wing, it would be within the mark to say that the swift, in a sense, ‘puts a girdle round the earth’ two or three times a month. Year after year the swifts return to the same localities to breed, and there are few towns, villages, hamlets, or even isolated mansions and farmhouses in the British Islands where this bird is not a summer guest. The bunch of swifts to be seen rushing round the tower of every village church are undoubtedly the same birds, or their descendants, that have occupied the place from time immemorial; and it is probable that the annual increase is just sufficient to make good the losses by death each year. It is hard to believe that a life so strenuous can last very long, and impossible to believe that birds so free of the air are subject to many fatal accidents. A spell of intense frost is very fatal to them in spring, but the cold is their only enemy in this country. The black swift, or ‘develing,’ or ‘screecher,’ as he is sometimes named, with his exceedingly long, stiff, scythe-shaped wings, still ‘urging his wild career’ through the air, is a figure familiar to everyone. And his voice, too, is a familiar sound to every ear. It is usually described as a harsh scream. Wild and shrill and piercing it certainly is, but it varies greatly with the bird’s emotions, and is at times a beautiful silvery sound, which many would hear with delight if uttered by the song-thrush or nightingale. The swift breeds in holes in church-towers and in houses, its favourite site being under the eaves of a thatched cottage; it also nests in crevices in the sides of chalk-pits and sea-cliffs, and sometimes in hollow trees. A slight nest of straw and feathers, made to adhere together with the bird’s saliva, is built, and two eggs are laid; they are oval in form, white in colour, and have rough shells. One brood only is reared in the season, and the birds depart at the end of August, but stragglers may be met with as late as October. * * * * *