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 (mythology) by creating the constellation Cygnus (Κύκνος), the Swan, in the sky. Leda and the swan and Leda and the egg were popular subjects in ancient art. In the post-classical arts, it became a potent source of inspiration. It is the subject of William Butler Yeats' poem Leda and the Swan. She is also the main subject in Honoré Desmond Sharrer's "Leda & the Folks", a large painting focusing as well on the parents of entertainer Elvis Presley and currently located at the Smith College Museum of Art. Leda (mythology) In Greek mythology, Leda (; Ancient Greek: Λήδα ) was an