 Besides his use of calendars and astronomical poetry, Ovid's multi-generic, digressive narrative and learned poem depends on the full range of ancient poetry and prose.In this, one of the most important works for Ovid was Callimachus' "Aetia"; the use of divine interlocutors, elegiac meter, various generic registers, and a focus on explaining the origins of customs and festivals are all significant features of Callimachus' work.The Fourth Book of Propertius, who claimed to be the Roman Callimachus, might also be a model since it also deals with aetiologies of Roman customs and myths.