THE PEREGRINE FALCON, which is the most common kind, is from fifteen to eighteen inches in length. The bill is blue at the base, and black at the point; the head, back, scapulars, and coverts of the wing are barred with deep black and blue; the throat, neck, and upper part of the breast are white, tinged with yellow; the bottom of the breast, belly, and thighs are of a grayish white; and the tail is black and blue. Wilson enumerates no less than ten varieties, dependent chiefly upon age, sex, and country. It is found, more or less abundantly, throughout the whole of Europe, principally in the mountain districts in North and South America, dwelling in the clefts of rocks, especially such as are exposed to the mid-day sun. It breeds upon the cliffs in several parts of England, but appears to be more common in Scotland and Wales. Its food consists principally of small birds; but it scruples not to attack the larger species, and sometimes gives battle even to the kite. Falcons rarely take their prey upon the ground, like the more ignoble birds of the class to which they belong; but pounce upon it from aloft, in a directly perpendicular descent as it flies through the air, bear it downwards by the united impulse of the strength and rapidity of their attack, and sticking their talons into its flesh, carry it off in triumph to the place of their retreat. Like most predatory animals, they are stimulated to action by the pressure of hunger alone, and remain inactive and almost motionless while the process of digestion is going on, until the renewed cravings of their appetite stimulate them to further exertion. In different stages of its growth, the Peregrine Falcon has been known by various English names. Its proper appellation among falconers is the Slight Falcon, the term Falcon Gentle being equally applicable to all the species when rendered manageable. In the immature state, this Falcon is also called a Red Hawk, from the prevailing colour of its plumage. The male is called a Tiercel, to distinguish it from the female, which, in the Falcon tribe, is commonly one-third larger than the male. In China there is said to be a variety, which is mottled with brown and yellow, and used by the emperor of China in his sporting excursions, when he is usually attended by his great falconer, and a thousand of inferior rank. Every bird has a silver plate fastened to its foot, with the name of the falconer who has the charge of it, that, in case it should be lost, it may be restored to the proper person; but if it should not be found, the name is delivered to another officer, called the guardian of lost birds, who, to make his situation known, erects his standard in a conspicuous place among the army of hunters.