Castor and Pollux horse breaker and the boxer / Polydeuces, my brothers" ..." – Helen, "Iliad" 3.253–255), but in the "Odyssey" they are treated as alive even though "the corn-bearing earth holds them". The author describes them as "having honour equal to gods", living on alternate days because of the intervention of Zeus. In both the "Odyssey" and in Hesiod, they are described as the sons of Tyndareus and Leda. In Pindar, Pollux is the son of Zeus while Castor is the son of the mortal Tyndareus. The theme of ambiguous parentage is not unique to Castor and Pollux; similar characterisations appear in
Leda and the Swan Leda and the Swan Leda and the Swan is a story and subject in art from Greek mythology in which the god Zeus, in the form of a swan, seduces the mortal woman Leda. According to later Greek mythology, Leda bore Helen and Polydeuces, children of Zeus, while at the same time bearing Castor and Clytemnestra, children of her husband Tyndareus, the King of Sparta. In the W. B. Yeats version, it is subtly suggested that Clytemnestra, although being the daughter of Tyndareus, has somehow been traumatized by what the swan has done to her mother (see below). According to