these birds as running rapidly with wings partially expanded, until suddenly meeting with a large clod they stop, squat, and disappear in a moment. At noon they may be seen near to each other dusting themselves and trimming their feathers. When the mother of a brood is discovered with her young, she ruffles up her feathers and tries every art to allure you from the place. On the larger branches of trees these birds walk with ease; but on smaller ones balance themselves with their wings. They usually roost singly on little risings of the ground, and a few feet apart. Their flight is strong, regular, tolerably rapid, and at times prolonged to several miles distance. [Illustration: _Plate 27. Cassell's Book of Birds_ COLUMBA LIVIA ____ ROCK PIGEON (_about one half Nat. size_)] "The Pinnated Grouse," says Audubon, "moves through the air with frequent beats, after which it sails with the wings bent downwards, balancing itself for a hundred yards or more, as if to watch the movements of its pursuer, for at this time they can be easily observed to look behind them as they proceed. They never rise when disturbed without uttering four or five distinct clucks, although at other times they fly off in silence. The ordinary voice of this species nearly resembles that of our domestic fowls, but during the pairing season the male utters a peculiar call. "The curious notes," continues the same writer, "emitted in the love season are peculiar to the male. When the receptacles of air above alluded to, which in form, colour, and size resemble a small orange, are perfectly inflated, the bird lowers its head to the ground, opens its bill, and sends forth, as it were, the air contained in these bladders in distinctly-separated notes, rolling one after another, from loud to low, and producing a sound like that of a large, muffled drum. This done, the bird immediately erects itself, refills its receptacles by inhalation, and again proceeds with its 'tootings.'" Audubon observed in those Prairie Hens he tamed, that after producing the noise the bags lost their rotundity and assumed the appearance of a burst bladder, but in a few seconds became again inflated. He caught one of these birds and pierced the air-cells with the point of a pin, after which it was unable to "toot" any more. Another bird, of which he punctured one cell only, was unable to inflate that one, but next morning could toot with the other, though not so loudly as before. As soon as the pairing and fighting season is over, the bladders collapse and are concealed beneath the feathers of the ruff. During the winter they are much reduced in size. The bladders and long neck-feathers are seen on the young males before the first winter, and in the spring attain maturity, but they increase in size and beauty for several years.