Arrian, Indica 7.1-8.1
[7.1] Megasthenes states that there are in all 118 peoples. I agree with Megasthenes myself that the Indian peoples are numerous, but I cannot conjecture how he learned and recorded the exact number, since he visited only a small proportion of India, and these peoples do not all mix with each other.
 The Indians, he says, were originally nomads, like the non-agricultural Skythians, who wander in their wagons and move from one part of Skythia to another, not swelling in cities and not reverencing shrines of the gods.
 Just so the Indians had no cities and built no temples, but were clothed with the skins of wild animals they would kill, and ate the bark of trees; these threes were called in the Indian tongue Tala, and what look like clews of wool grew on them, just as on the tops of palm trees.  They also fed on what game they had captured, eating it raw, at least until Dionysos reached India.
 But when he arrived and became master of India, he founded cities, gave them laws, bestowed wine on the Indians as on the Greeks, and taught them to sow their land, giving them seed.  Either Triptolemos did not come this way when he was sent out by Demeter to sow the entire earth, or it was earlier than Triptolemos that this Dionysos, whoever he was, traversed Indian and gve the Indians seeds of domesticated plants.
 Dionysos first yoked oxen to the plough and made most of the Indians agriculturalists instead of nomads, and equipped them also with eth arms of warfare.  He also taught them to reverence various gods, but expecially of course himself, with clashing of cymbals and beating of drums;  he instructed them to dance in the Satyric fashion, the dance called among Greeks the kordax, and instructed them in the use of perfumed ointments, so that even against Alexander the Indians came to battle to the sound of cymbals and drums.
[8.1] When departing from India, after setting all this in order, Dionysos made Spatembas king of the land, one of his companions who was most expert in Bacchic rites…