These birds are met with throughout the whole of Europe, Asia, and North America, but are quite unknown in Africa. All are, without exception, stationary in their habits, and rarely undertake expeditions to any great distance from their native haunts. During the period of incubation they live alone or in pairs, but at other times in parties, which often unite into large flocks. Their food consists of fruits, seeds, the young shoots of plants and trees, insects, and larvæ. Some species are polygamous, but many pair; in the latter case, at least, both males and females assist in rearing the young. Although by no means highly endowed, the _Tetraones_ have their sense of sight and hearing well developed. They walk quickly, but fly heavily, and with much noise, resorting but rarely to this means of progression, and never rising to any height in the air. The increase of these birds is very rapid, the female laying from eight to sixteen eggs, oval in shape, smooth, yellowish, and spotted with brown. No actual nest is prepared for their reception, a slight hollow in the earth, carelessly lined with some soft material, being all that is required for the purpose, provided that the situation is sufficiently retired to secure the safety of the young. We are told by several Swedish naturalists that not only are these birds subject, like their congeners, to many changes of plumage, but that they cast their claws, and at the same time the horny fringes with which their toes are defended. THE CAPERCALI. The CAPERCAILLIE, CAPERCAILZIE, or CAPERCALI (_Tetrao urogallus_), the largest and finest species of the above group, is of a blackish hue on the crown of the head and throat; the nape is deep grey, marked with undulating black lines; the back pale black, powdered with grey and reddish brown; the tail black, spotted here and there with white; the breast glossy steel-green, and the rest of the under side spotted more or less distinctly with black and white. The eye is brown, the bare skin that surrounds it bright red, and the beak greyish white. This noble bird is from two feet two inches to two feet five inches long, its breadth being from four feet four inches to four feet seven inches; the wing measures from fifteen to seventeen, and the tail from thirteen to fourteen inches.