The only other notable river on the western coast is the Silarus (Sele), which descends by a channel of about sixty miles from the central Apennines of Lucania into the Bay of Pæstum or Salerno. In the foot of Italy the mountains come down so close to the sea that from the mouth of the Silarus to the lower angle of the Gulf of Tarentum, the streams are but short and rapid torrents. Of these it is said that no fewer than eighty may be enumerated between Pæstum and the Straits of Messina. The Gulf of Tarentum receives some streams of importance. The Bradanus and Casuentus (Basento) enter the gulf within four miles of each other after a course of about sixty miles. The Aciris (Agri) is to the south of these. The Siris (Sinno), notable as the scene of the first battle between Pyrrhus and the Romans, is a mere torrent, as is the Galesus upon which Tarentum stands. The northern or Adriatic coast is almost devoid of lateral valleys, such as are found on the other coast, and therefore has few considerable streams. The Aufidus (Ofanto) in Apulia, renowned in Roman history from the fact that the fatal battle of Cannæ took place upon its banks, rises on the opposite side of the same range from which the Calor flows, and runs a course of about eighty miles. The Sagrus (Sangro) stands in the same relation to the Vulturnus as the Aufidus does to the Calor, and conveys the waters of the Fucine Lake from the Æquian hills through Samnium, by a nearly similar length of channel. But the largest river of this side is the Aternus, which finds its way from the Sabine hills into a valley parallel to the main range, and thus prolongs its course. It is joined by a number of smaller streams, and attains a considerable volume of water before it reaches the sea at the point where the Marrucinian coast abuts on that of Picenum. The whole coast from Mount Garganus northward is ploughed by numberless torrents which descend in rapid course down steep mountain gorges. Of these we need but name the Æsis between Picenum and Umbria; the Metaurus in Umbria, famous for the defeat of Hasdrubal; the Rubicon, which formed the boundary of Roman Italy on the northern side, as did the Macra (Magra) on the opposite coast. The limestone mountain tract that occupies the whole narrow peninsula from the great valley of the Po downwards is often too steep, bare, and rugged to be capable of cultivation. There are, however, many rich plains of limited extent, among which Campania ranks first; and many narrow but fertile valleys, in which nature rewards the smallest labour with bountiful returns. [Illustration: ANCIENT ROMAN TOWER NEAR ROME]