The whole story is built up on the well-known _Mãrchen_ formulæ of the "True Bride" and the "Two Brothers," but accommodated to well-known mythic personages, and the _grianan_ is the Celtic equivalent of various objects in stories of the "Cinderella" type, in which the heroine conceals herself, the object being bought by the hero and kept in his room.[289] Thus the tale reveals nothing of Etain's divine functions, but it illustrates the method of the "mythological" school in discovering sun-heroes and dawn-maidens in any incident, mythical or not. Oengus appears in the Fionn cycle as the fosterer and protector of Diarmaid.[290] With Mider, Bodb, and Morrigan, he expels the Fomorians when they destroy the corn, fruit, and milk of the Tuatha Dé Danann.[291] This may point to his functions as a god of fertility. Although Mider appears mainly as a king of the _síde_ and ruler of the _brug_ of Bri Léith, he is also connected with the Tuatha Déa.[292] Learning that Etain had been reborn and was now married to King Eochaid, he recovered her from him, but lost her again when Eochaid attacked his _brug_. He was ultimately avenged in the series of tragic events which led to the death of Eochaid's descendant Conaire. Though his _síd_ is located in Ireland, it has so much resemblance to Elysium that Mider must be regarded as one of its lords. Hence he appears as ruler of the Isle of Falga, i.e. the Isle of Man regarded as Elysium. Thence his daughter Bláthnat, his magical cows and cauldron, were stolen by Cúchulainn and Curoi, and his three cranes from Bri Léith by Aitherne[293]--perhaps distorted versions of the myths which told how various animals and gifts came from the god's land. Mider may be the Irish equivalent of a local Gaulish god, Medros, depicted on bas-reliefs with a cow or bull.[294]