25. Near to this is the region of the Chaldæans, the nurse of the ancient philosophy, as the Chaldæans themselves affirm; and where the art of true divination has most especially been conspicuous. This district is watered by the noble rivers already mentioned, by the Marses, by the Royal river, and by that best of all, the Euphrates, which divides into three branches, and is navigable in them all, having many islands, and irrigating the fields around in a manner superior to any industry of cultivators, making them fit both for the plough and for the production of trees. 26. Next to these come the Susians, in whose province there are not many towns; though Susa itself is celebrated as a city which has often been the home of kings, and Arsiana, and Sele, and Aracha. The other towns in this district are unimportant and obscure. Many rivers flow through this region, the chief of which are the Oroates, the Harax, and the Meseus, passing through the narrow sandy plain which separates the Caspian from the Red Sea, and then fall into the sea. 27. On the left, Media is bounded by the Hyrcanian Sea;[144] a country which, before the reign of the elder Cyrus and the rise of Persia, we read was the supreme mistress of all Asia after the Assyrians had been conquered; the greater part of whose cantons had their name changed into one general appellation of Acrapatena, and fell by right of war under the power of the Medes. 28. They are a warlike nation, and the most formidable of all the eastern tribes, next to the Parthians, by whom alone they are conquered. The region which they inhabit is in the form of a square. All the inhabitants of these districts extend over great breadth of country, reaching to the foot of a lofty chain of mountains known by the names of Zagrus, Orontes, and Jasonium. 29. There is another very lofty mountain called Coronus; and those who dwell on its western side abound in corn land and vineyards, being blessed with a most fertile soil, and one enriched by rivers and fountains. 30. They have also green meadows, and breeds of noble horses, on which (as ancient writers relate, and as we ourselves have witnessed) their men when going to battle mount with great exultation. They call them Nesæi.[145] 31. They have also as many cities as Media, and villages as strongly built as towns in other countries, inhabited by large bodies of citizens. In short, it is the richest quarter of the kingdom. 32. In these districts the lands of the Magi are fertile; and it may be as well to give a short account of that sect and their studies, since we have occasion to mention their name. Plato, that most learned deliverer of wise opinions, teaches us that Magiæ is by a mystic name Machagistia,[146] that is to say, the purest worship of divine beings; of which knowledge in olden times the Bactrian Zoroaster derived much from the secret rites of the Chaldæans; and after him Hystaspes, a very wise monarch, the father of Darius.