if this had not been the traditional form in Bactria (p. 28). The Achæmenids did not strike coins of this kind, and this shape must therefore have come down from a period anterior to them. The frequent mention of the physician, on the other hand, ought not to be regarded as a proof of later composition, for we hear of the physician and his remedies in ancient poems of the Veda (IV. 35). In regard to the antiquity of the Avesta, then, we can only build upon the simple facts that it cannot have been written down for the first time when the Buddhists found adherents in Bactria (IV. 542), or when the kingdom of the Greek princes arose in Bactria, or when the Seleucidæ and Alexander, before them, reigned over Iran. It has been proved that the Avesta was in existence before Alexander overthrew the kingdom of the Achæmenids. The series of the successors of Zarathrustra, which western writers could trace backwards from this point--Osthanes II., Pazates, Gobryas, Osthanes I., Astrampsychus, Apusodorus--plainly shows that even under the Achæmenids the West was seriously occupied with religious questions. As Osthanes I. had written on the doctrine of Zoroaster about the time of Xerxes (p. 92), it is at least more probable than not that the Avesta was already in existence at that time. If in the West there was a series, and as the Greeks point out, a continuous series, of priestly teachers, round whom naturally pupils and schools grew up, and after the beginning of the fifth century a theological literature, similar teachers and schools must have existed long before in the East, and this greatly strengthens the conclusion drawn from the contents of the Vendidad, that it must have been written down before the rise of the Medes. But for any more precise determination of the date of the Avesta between the two limits obtained--the year 750 B.C., _i.e._ the beginning of the formation of a priesthood in the West and the contemporary use of writing in the East, and the year 350 B.C.--we are confined wholly to internal evidence.