According to Herodotus the satrapy of the Indians paid the highest tribute in the whole Persian kingdom; each year it had to deliver 360 talents of gold to the king. The gold for this payment was obtained, as Herodotus tells us, from a great desert, which lay to the east beyond the Indus. Of that region no one could give any account. Where the desert began there were ants, smaller than dogs and larger than foxes, which dug up gold sand, when after the manner of ants they excavated their nests in the ground. This sand the Indians took, put in sacks, and carried it off as quickly as possible on the swiftest camels; for should the ants overtake them, neither man nor beast could escape; occasionally ants of the kind were captured and brought to the Persian king.[509] This marvellous story is repeated by Megasthenes with even more definite statements; the Indians who dwelt in the mountains of that region are called Derdæ; the mountain plain, in which the ants are found, is three thousand stades (about 400 miles) in circuit; the sand thrown up by these animals requires but little smelting; and Nearchus assures us that the skins of the ants are like those of panthers.[510] That the Greeks are not relating a fable of their own invention is proved by the Mahabharata, according to which the tribes which dwell in the mountains of the north bring "ant gold" to Yudhishthira as a tribute.[511] The Derdæ of Megasthenes must be the Daradas, whom the book of the law counts among the degenerate races of warriors.[512] Even at this day the Dardus dwell on the upper course of the Indus to the north of Cashmere, in the valley of the Nagar, which flows into the Indus from the north, to the east of the highest summits as far as Iskardu, on the Darda-Himalayas (so called after the tribe), and speak a dialect of Sanskrit.[513] Adjacent to this almost inaccessible mountain-land are table-lands, where the sandy soil contains gold-dust. Numerous marmot-like animals with spotted skins, of which the largest are about two feet long,[514] burrow in this soil. The traveller who first penetrated this region in our times informs us: "The red soil was pierced by these animals, which sat on their hind legs before their holes, and seemed to protect them."[515] We may assume that the Daradas carried away the loose sand which these animals threw up in making their winter holes, in order to extract the gold from it; and the Aryas on the lower Indus and the Ganges, who did not know the marmot, compared them with the ants, which, among them, built and dug holes in the earth, and assuming that they were a large species of ant, called the gold of the north after them (_pipilika_). What the Greeks tell us of the swiftness and dangerous nature of these animals is fabulous.