The Greeks identified this constellation with the nymph Callisto, placed in the heavens by Zeus in the form of a bear together with her son Arcas as " bear-warder," or Arcturus; they named it Arctos, the she-bear, Helice, from its turning round the pole-star.
PAN (" pasturer"), in Greek mythology, son of Hermes and one of the daughters of Dryops ("oak-man"), or of Zeus and the nymph Callisto, god of shepherds, flocks and forests.
Zeus, to conceal the amour, changed Callisto into a she-bear; Hera, however, discovered it, and persuaded Artemis to slay Callisto, who was placed amongst the stars as iiptcros (" the bear").
There is no doubt that Callisto is identical with Artemis; her name is an obvious variation of KaXMiaTrt, a frequent epithet of the goddess, to whom a temple was erected on the hill where Callisto was supposed to be buried.
Callisto was originally a bear-goddess worshipped in Arcadia, identified with Artemis, when nothing remained of the original animal-worship but name and ritual.
The worship of Callisto being merged in that of the greater divinity, she became the handmaid and companion of Artemis.
On the other hand, the Artemis of Arcadia, who is confused with the nymph Callisto, who, again, is said to have become a she-bear, and later a star, and the Brauronian Artemis, whose maiden ministers danced a bear-dance, are goddesses whose legend seems unnatural, .and is felt to need explanation.
According to the legend, Callisto, an Arcadian nymph, became by Zeus the mother of Arcas, the eponymous hero of the Arcadians.
Subsequently Areas, when hunting, chanced to pursue his mother Callisto, who had been transformed into a bear, as far as the temple of Lycaean Zeus; to prevent the crime of matricide Zeus transported them both to the heavens (Ovid, Metam.