ἐν παντὶ γάρ τοι σκορπίος φρουρεῖ λίθῳ → for a scorpion keeps watch at every stone
quingentēsĭmus: a, um, adj. id.,I the five hundredth (class.): annus, Cic. Fl. 1, 1; so Plin. 15, 1, 1, § 2.
