[551] The Grecian authors above-quoted call the rapacious birds used for pursuing game ἱέρακες; and Pliny calls them _accipitres_. It would be difficult, perhaps impossible, to distinguish with sufficient accuracy all the species of these birds to which the ancients gave different names. This genus is numerous, and the species often differ so little from each other, that it is not easy to establish their characterizing marks. Besides, they for the most part change their colour, and often their whole appearance, according to their age or the season of the year; so that these characters become very uncertain. It appears that on this account the ancients often divided one species into two or more, and imagined that many species passed one into the other, or that new species were produced by the mixture of different breeds. It seems however certain that the ancients divided those birds of prey which fly abroad in the day-time, into three species: ἀετὸς aquila; γὺπς vultur; and ἱέραξ accipiter. The first and last belong to that genus which Linnæus calls _falco_, and are the large species of it. The vultures are the Ger-falcons, which are sufficiently distinguished by their bald head and neck. [552] “Respecting Thrace which is situated above Amphipolis, a wonderful thing is related, which might appear incredible to those who had never heard it before. It is said that boys go out into the fields, and pursue birds by the assistance of hawks. When they have found a place convenient for their purpose, they call the hawks by their names, which immediately appear as soon as they hear their voices, and chase the birds into the bushes, where the boys knock them down with sticks and seize them. What is still more wonderful, when these hawks lay hold of any birds, they throw them to the fowlers; but the boys, in return, give them some share of the prey.”--De Mirabilibus Auscultat. cap. 128. [553] Antigoni Carystii Historiæ Mirabiles, cap. 34. [554] “Hawks, which are no less fit for fowling than eagles, and which are not inferior to them in size, are of all birds reckoned to be the tamest and the fondest of man. I have heard that in Thrace they accompany people when they go out in quest of birds in the fens. The fowlers, having spread their nets, remain quiet, while the hawks flying about terrify the birds, and drive them into them. When the Thracians catch any birds, they divide them with the hawks, by which means they render them faithful partners in fowling; if they did not give them a share of the booty, they would be deprived of their assistance.”--Histor. Anim. lib. ii. cap. 42. [555] Lib. x. c. 8. In a part of Thrace above Amphipolis, men and hawks go out a-fowling, as it were in company. The former drive the birds from among the bushes and reeds, and the latter flying after them strike them down. The fowlers divide with them their prey.