climates, this happens but once in the year. The Pigeons, on the contrary, are all of them strictly monogamous, and the female lays but two eggs for each sitting, although she has several broods. In the Gallinaceous tribes the male renders no assistance to the female, either in the construction of the nest or in the care of their progeny. The chickens are born with their eyesight perfect, and as soon as they escape from the egg-shell are able to run about, and procure for themselves their own food. The principal distinctive character of the _Columbæ_ is furnished by the structure of the bill. The upper mandible consists of a horny apical portion, which is often of considerable length and strength, but its base is formed by a convex cartilaginous plate, in the anterior portion of which the nostrils are situated. The skin covering the cartilaginous portion is of a soft texture, very different from the rest of the bill. It is sometimes smooth, and clothed with a sort of scurf, but in other cases it is warty, or even developed into a fleshy wattle. This is especially the case in some domesticated varieties of the Pigeon. The _Columbæ_ are provided with short tarsi and moderately long toes, all scutellated. The toes are four in number, three in front and one behind. The anterior toes are not united by a membrane at the base. The hinder toe is placed on the same plane with those in front, and the whole sole of the foot is formed of soft papillated pads, which are usually a good deal wider than the scutellated upper portion of the toes. The wings, which are generally long and pointed, contain ten primary quills, and the tail usually consists of twelve feathers, although in some cases there are sixteen. Another important character distinguishing these birds, as compared with the _Gallinæ_, is that their feathers are destitute of the plumules, or accessory plumes, which are greatly developed in Gallinaceous Birds. The form of the wing in Pigeons is sufficient to indicate that they are capable of powerful flight, and many of them are remarkable for the speed with which they traverse the air, especially when engaged in their migrations. Most of them are arboreal, and nestle in the holes of trees; others frequent rocks, but all perch with great facility; nevertheless, they generally seek their food upon the ground, and walk or run without difficulty. They are also remarkable for their mode of drinking, in which they differ from all other birds. The general practice of birds in drinking is to take up a small portion of water in the bill, and then, by raising the head, to allow it to run down into the throat. The Pigeons, on the contrary, dip their bills into the water, and hold them there till they have quenched their thirst. These birds are inhabitants of the warmer and temperate regions of the earth, but they are found in most abundance in hot climates, where, also, their plumage attains a brilliancy of which