Those that are bred in the Alps, although very small of body, give a great quantity of milk, and are capable of enduring much labour; they are yoked by the horns, and not by the neck. The oxen of Syria have no dewlap, but they have a hump on the back. Those of Caria also, which is in Asia, are unsightly[1955] in appearance, having a hump hanging over the shoulders from the neck; and their horns are moveable;[1956] they are said, however, to be excellent workers, though those which are either black or white are condemned as worthless for labour.[1957] The horns of the bull are shorter and thinner than those of the ox. Oxen must be broken in when they are three years old; after that time it is too late, and before that time too early. The ox is most easily broken in by yoking it with one that has already been trained.[1958] This animal is our especial companion, both in labour generally, and in the operations of agriculture. Our ancestors considered it of so much value, that there is an instance cited of a man being brought before the Roman people, on a day appointed, and condemned, for having killed an ox, in order to humour an impudent concubine of his, who said that she had never tasted tripe; and he was driven into exile, just as though he had killed one of his own peasants.[1959] The bull has a proud air, a stern forehead, shaggy ears, and horns which appear always ready, and challenging to the combat; but it is by his fore feet that he manifests his threatening anger. As his rage increases, he stands, lashing back his tail[1960] every now and then, and throwing up the sand against his belly; being the only animal that excites himself by these means. We have seen them fight at the word of command, and shown as a public spectacle; these bulls whirled about and then fell upon their horns, and at once were up again; then, at other times, they would lie upon the ground and let themselves be lifted up; they would even stand in a two-horsed chariot, while moving at a rapid rate, like so many charioteers.[1961] The people of Thessaly invented a method of killing bulls, by means of a man on horseback, who would ride up to them, and seize one of the horns, and so twist their neck. Cæsar the Dictator was the first person who exhibited this spectacle at Rome.