In no species is the union with the wild animal so easy as in that of the swine; the produce of such unions was called by the ancients hybrid,2082 or half savage; which appellation has also been transferred to the human race, as it was to C. Antonius, the colleague of Cicero in his consulship. Not only, however, with respect to the hog, but all other animals as well, wherever there is a tame species, there is a corresponding wild one as well; a fact which is equally true with reference to man himself, as is proved by the many races of wild men of which we have already spoken.2083 There is no kind of animal, however, that is divided into a greater number of varieties than the goat. There are the capræa,2084 the rupicapra or rock-goat, and the ibex, an animal of wonderful swiftness, although its head is loaded with immense horns, which bear a strong resemblance to the sheath of a sword.2085 By means of these horns the animal balances itself, when it darts along the rocks, as though it had been hurled from a sling;2086 more especially when it wishes to leap from one eminence to another. There are the oryges also,2087 which are said to be the only animals that have the hair the contrary way, the points being turned towards the head. There are the dama also,2088 the pygargus,2089 and the strepsiceros,2090 besides many others which strongly resemble them. The first mentioned of these animals,2091 however, dwell in the Alps; all the others are sent to us from the parts beyond sea.