The graylag goose which breeds in the British Isles, seems to be the ancestor of the domestic geese that we see in every farmyard. It lives in flocks, which frequent marshes, lakes, and boggy moors during the greater part of the year, but often visit the sea-coast in winter. Sometimes, too, they may be seen near the mouth of a great river. They are very shy birds, and when sportsmen wish to shoot them they have to resort to all kinds of tricks in order to approach them without being seen. When wild geese fly, they generally do so in the form of a half-opened pair of compasses, with the angle in front. But now and then they may be seen in the air in an irregular wavy line. As they fly they make a curious "gaggling" cry, which can be heard from a very long distance. The nest of this goose is made of grass and flags, and is generally placed at the base of a tussock of coarse grass. It usually contains six plain white eggs. Swans, too, are found wild in many parts of the world, and used to be almost as numerous as ducks or geese both on the inland lakes and along the coasts of the United States, but now have become rare and shy. All the species breed in the arctic regions, and appear among us only on their migrations in spring and fall. Swans are most graceful birds in the water, and as their limbs are set very far back they can swim with great ease. But for the same reason they are very clumsy upon dry ground, and waddle along in the most awkward way, seeming to find it very difficult to keep their balance. All those in our parks are tame; but during the nesting-season the male swan generally becomes very savage, and will attack any one who ventures too near to his nest. And as a single stroke from his wing is sufficient to break a man's arm, he is apt to be dangerous when unfriendly. The nest of the swan is a very large structure of reeds, rushes, and grass, and is generally placed quite close to the water's edge. It contains six or seven large greenish-white eggs. A great many kinds of duck are known, but we can only mention the common wild duck, which still visits rivers and lakes every winter in considerable numbers, a few of which remain to breed. The male duck is called the mallard, and from October till May he is a very handsome bird, with a dark-green head and neck, a white collar round the lower part of his throat, brownish-gray wings, chestnut-brown breast, and white hinder parts. But when he moults he puts off this beautiful plumage, and for the next five months is mottled all over with brown and gray, just like his mate.