Gemini : Myths and Legends
Gemini is the 3rd sign of the zodiac, represented by the Greeks as two children, although the Egyptians thought of it as two kids and the Arabs as two peacocks. The Greek twins are usually Castor and Pollux (the Latinised form of the original Greek, Polydeukes). They may be Herakles and Apollo or the pair connected with Demeter: Triptolemus (the 'thrice-daring' herdsman) and Lasion (struck dead by Zeus for consorting with Demeter in a 'thrice ploughed' field).
Mythology: Castor and Pollux were members of Jason's crew aboard the Argo. They were the sons of Queen Leda of Sparta, but had different fathers. Pollux's father was Zeus, and that of Castor was King Tyndareus. The job of the twins was to protect the mariners, appearing, in the rigging, as St. Elmo's fire Cancer (the Crab), which refers to the next zodiac constellation.