According to Xenophon in Cynegeticus, "Castorian hounds are so called because it was Castor, a keen hunter, who kept the breed pure.[...] Vulpine hounds are named after the fact that they are a cross between dogs and foxes [...]." Xenophon (30 March 2006). "On Hunting". Hiero the Tyrant and Other Treatises. Translated by Waterfield, Robin. UK: Penguin. ISBN9780141959627. Retrieved 10 February 2023.