to these; their feet, though formed on the Passerine type, yet allow them to walk with ease and freedom; and many of the species habitually spend their time on the ground, perching very little; the gait and manners of some species are closely like those of the Poultry, and there is a sensible approximation to the latter in the tones of their peculiar voice. But, the differences are more important than the agreements of these groups: the Gallinaceous birds in general do not pair, but each male associates with many females; they lay many eggs each time they incubate, which is rarely more than once a year, at least in the temperate zones; while the Pigeons, as has been said, mate, and form permanent connubial attachments; the females lay only two eggs at each time, but incubate frequently during the year. In the Gallinaceous Order the posterior toe is jointed upon the tarsus higher up than the other toes, and touches the ground in walking only with the claw, or at most with the extreme joint, and remains perpendicular when the bird is on the perch. In the Pigeons, the hind toe is articulated at the bottom of the tarsus on the same level as the others, resting on the ground throughout its length, and embracing the branch in perching.
On the whole, then, we adhere to the opinion of those ornithologists who regard the Pigeons as an Order of birds, containing but a single Family.
