The BLACK-NECKED SWAN (_Cygnus nigricollis_) is a beautiful bird, inhabiting South America, and recognisable from its northern brethren by the shortness of its wings, which do not extend beyond the base of the tail, which is composed of eighteen feathers, and by the black in its plumage. In this bird the entire body is white with black head and neck, the former enlivened by a white line upon the brow. The eye is brown, and the beak lead-grey; the cere and bare cheek-stripes are blood-red, and the feet pale red. This species is forty-eight inches long, the wing measures fourteen, and the tail from six to seven inches. The habitat of the Black-necked Swan is limited to the most southern portion of America, extending from South Peru to the Falkland Islands, and from that point along the east coast as far as Santos in Brazil. The residence of these birds varies with the season of the year; during the spring and autumn they are met with in small parties about Buenos Ayres on their way to their more northern haunts, where they remain throughout the winter, when they return south to breed. During the period of incubation they occupy the lagoons and lakes of the interior, and after that season unite with their own and allied species into large flocks. The flight of this Swan is light and beautiful, but in other respects it is without the grace that characterises most members of this family. While swimming the neck is held erect, after the manner of a Goose. We are without particulars concerning the incubation of these birds, beyond that when first hatched the young are covered with white down, and that they grow with such rapidity that by the autumn they are scarcely distinguishable from their parents. The late Earl of Derby was presented with the first Black-necked Swan ever brought to Europe; to this were afterwards added seven more. After the death of the Earl two were presented to her Majesty, and the rest consigned to the Zoological Gardens, in the Regent's Park, where they lived for many years without breeding. In 1856, however, a pair commenced a nest, but did not lay until the following year, since which time they have incubated annually. THE BLACK SWAN.