Now if my interpretation of this story is right and the practice of human sacrifice to _genii_ was known in ancient Greece, the transition from the worship of _genii_ in the form of snakes or dragons to the worship of tutelary heroes or gods in human likeness is readily explained on the analogy of a similar transition in modern belief. What was originally the victim was mistaken for the genius. The same confusion of thought, by which, in one version of ‘the Bridge of Arta,’ the _genius_ in person demands a human victim and yet afterwards the victim speaks of herself as becoming the _genius_ of the bridge, can be detected even in the oracle given to the Messenians. ‘If ye fail to find a maid of the blood of the Aepytidae,’ it said, ‘ye may take the daughter of a man of other lineage, provided that he give her willingly for sacrifice.’ Why the condition? Why ‘willingly’ only? Because, I think, even the Delphic oracle halted between two opinions--between the conception of the maiden as a victim to appease angry _genii_ and the belief that the dead girl herself would become the guardian-_daemon_ of the stronghold. Let us read another story from Pausanias[717]: ‘At the base of Mount Cronius, on the north side (of the Altis at Olympia), between the treasuries and the mountain, there is a sanctuary of Ilithyia, and in it Sosipolis, a native _daemon_ of Elis, is worshipped. To Ilithyia they give the surname “Olympian,” and elect a priestess to minister to her year by year. The old woman too who waits upon Sosipolis is bound by Elean custom to chastity in her own person, and brings water for the bathing of the god and serves him with barley-cakes kneaded with honey. In the front part of the temple, which is of double construction, is an altar of Ilithyia, and entrance thereto is public; but in the inner part Sosipolis is worshipped, and only the woman who serves the god may enter, and she only with her head and face covered by a white veil. And while she does so, maidens and married women wait in the temple of Ilithyia and sing a hymn; incense of all sorts is also offered to him, but no libations of wine. An oath also at the sanctuary of Sosipolis is taken on very great occasions.