In the Metamorphoses, Ovid suppresses certain elements of the myth of Medea and supplements others. The focus of his alterations, it seems, is on language itself, and particularly on the relation of language to metamorphosis. He returns again and again to Medea's use of incantation. Whether in the story of Jason and the golden fleece or of Aeson's rejuvenation, Ovid emphasizes the efficacy of language. He suggests the relationship of words to transformation through Medea's exercise of magic, indeed literalizes the connection between ritual language and transformed phenomena in the metamorphoses that follow her magic rites. But magic functions also as a metaphor for imaginative power, since it possesses the capacity shared by poet and magician to transform. In the several depictions of Medea's magic art — and one can perceive the episodes of the myth structured around their connections with magic — Ovid develops an image for imagination itself. Jason's labors, for example, are affected by Medea's expertise in magic; they are also a vehicle for a self-conscious display of poetic power. Ovid asserts his imaginative superiority more clearly in the case of Medea, whose relation even to her own power is ambiguous. But let us first consider the portrayal of Medea as a teller of her own tale and the poet's nod in the direction of his predecessors.