Further to the east, where the Caspian Sea ends and the mountains of Iran descend towards the desolate, pathless steppes of the Oxus, is a wild, hilly country. In the depressions, and there only, the region of the Parthians (_Parthava_ in the inscriptions of the Achæmenids[12]) exhibits fruitful lands, and, further eastward still, agriculture is favoured by the long, narrow valley of the Areios (Herirud). Springing from the southern slope of the Hindu Kush, the river flows towards the west along the inner edge of the table-land, till it bursts through the northern barrier in order to lose itself in the sand of the steppes. In this valley the district of the modern Herat, lay the Areians, who are called _Haraiva_ in the inscriptions of the Persian kings. The name points to the possession of water. To the north of the Areians, in the valley of the Margos (now Murghab), which rises in the northern edge of the table-land, and flows to the north-west, where it also ends in the sands of the desert, in Margiana (Old Persian, Marghush; Bactrian, Mouru; modern Merv), lay the Margiani, in a well-cultivated region, rich in vineyards, with numerous cities and a large population. But the fertility only extends so far as the soil can be watered from the Margos and the neighbouring streams. At the foot of the mountain barrier, towards the northern steppes, and on the edge of the steppes of the Oxus, to the north of the Hyrcanians, Parthians, and Margiani, in a land which only partially admits of agriculture, lay the Chorasmians, a people partly stationary and partly migratory--the _Uvarazmiya_ of the Achæmenids, the _Hvairizem_ of the Avesta. Further to the east, where the edge rises to the lofty Hindu Kush, there lies on its northern slope a favoured district in the region of the Upper Oxus. That river flows from the table-land of Pamire, which lies more than 15,000 feet above the sea, exactly at the point where the Hindu Kush abuts on the Belurdagh, the western edge of the central table-land. On the banks of the river, which flows in a north-westerly direction, extend broad mountain pastures, where support is found in the fresh mountain air for numerous herds of horses and sheep, and beneath the wooded hills are blooming valleys. On these slopes of the Hindu Kush, the middle stage between the table-land and the deep plain of the Caspian Sea, lay the Bactrians--the _Bakhtri_ of the Achæmenids, the _Bakhdhi_ of the Avesta. Curtius, following the accounts of the companions of Alexander, tells us of the land of the Bactrians that it was much diversified in character; in one part were pastures, another was rich in beautiful fruit-trees and vines, and frequent springs watered the rich soil, on which corn was cultivated. These districts supported a large number of oxen and horses. Under the range of Paropanisos (_i.e._ on the slope of the Hindu Kush) lay the city of Bactra, on the river of the same name, which washed its walls. But a