Diodorus Siculus attests and approves the hereditary succession of the priesthood among the Egyptians, the Chaldeans, and the Indians (1. i. [c. 73] p. 84, 1. ii. [c. 29 and 40] p. 142, 153, edit. Wesseling). The Magi are described by Ammianus as a very numerous family: "Per saecula multa ad praesens una eademque prosapia multitudo creata, Deorum cultibus dedicatur" (xxiii. 6). Ausonius celebrates the Stirps Druidarum (De Professorib. Burdigal. iv. [7]); but we may infer from the remark of Caesar (Bell. Gall. vi. 13), that in the Celtic hierarchy some room was left for choice and emulation.