Perhaps the leading characteristic in the flying of this kind of hawk is that it habitually captures its prey, or, as falconers term it, "quarry," by making a dash or shot at it, technically called a stoop, from some position where it can command an advantage in speed and force. In many cases the bird is itself so conscious of this natural aptitude for stooping in preference to mere following, that it habitually places itself, when on the look-out for food, at a considerable height, from which it can descend with great ease and velocity upon any victim which may happen to be passing beneath, using the principle of gravity to increase the force of its downward flight; and in several departments of the falconer's art the trainer endeavours to encourage the tendency of his hawk to mount and make the most of the advantage so gained. The long-winged hawks are as a rule trained to come to the lure, and not to the fist, although for the sake of convenience it is sometimes found advisable to make them to both practices. Greenland Falcon (_Falco candicans_) Female--Length, about 23 inches; wing, 16.5; tail, 9. Male--Length, about 20 inches; wing, 14.5; tail, 8. The general colour in the adult of both sexes is white, with more or less faint bars of light brownish grey on the upper plumage, and spots of the same colour underneath. The young birds of both sexes are considerably darker than their elders, with a much larger allowance of darker grey brown on the plumage both above and below. These dark patches and markings become fainter and less abundant at each moult, until in very old birds they almost vanish, leaving the hawk to appear at a distance merely white. The bars on the back, shoulders, and wings are often shaped like the two arms of an anchor; and the spots on the breast are mostly tear-shaped, especially after the first moult. The legs, feet, cere, and eyelids are bluish grey in the young birds, but after the first moult become yellow, strengthening in colour at each moult. It will be seen by reference to the remarks on comparative merits of falcons (Chap. XVIII.), that in proportions this species excels all the other gers. It is also the most majestic in its appearance and attitudes, and the most noble in the expression of its eyes and, if the term may be permitted, of its countenance. It was not so much used in the Middle Ages as the other gers, by reason of the difficulty of obtaining it, but was probably the most highly valued of all. The late Lord Lilford, who in quite modern times had a good deal of experience with this species, opined that it was an excellent flier and stooper, but a poor "footer," that it was the reverse of hardy, and difficult to keep in condition. When observed in the wild state in Scotland it was found to kill a great many rooks, and to be dreaded by the wild-fowl, but not to be partial to game, though it was seen to make an ineffectual stoop at a blackcock. Iceland Falcon (_Falco islandus_)