Arabs who now form a class of _genii_ were originally the human victims preferred at the sinking of wells--a piece of engineering, it must be remembered, of first-rate importance in a country as dry as Greece--and that, when once these _genii_ had become associated with water, the popular imagination soon assigned them to rivers and natural springs no less than to wells. The _genii_ of rivers sometimes appear also in the shape of bulls, though as I have already remarked this type of _genius_ is far more commonly associated with churches. Possibly in some cases the fact that the church was built in the neighbourhood of some sacred spring, whose miraculous virtue was of older date and repute than Christianity, first caused the transference; but at any rate some rivers still retain this type of _genius_, the type under which river gods were regularly represented in ancient times. In this connexion a story entitled ‘the ox-headed man[733]’ and narrated to me at Goniá in the island of Santorini deserves mention. A princess and a poor girl once agreed that when they were married, if of their respective first-born the one should be a boy and the other a girl, these two should be married. Now, as it chanced, princess and peasant-maid were both wed on the same day, but for a long time both remained childless. Then at last they prayed to the Panagia, the princess for a child even if it were but a girl, the peasant for a son even if he were but half a man; and their prayers were answered; for the poor woman bore a son with the head of an ox, while the princess was blest with a beautiful daughter. When the two children were grown up, the poor woman went one day to claim the fulfilment of the agreement, and the princess, or rather now the queen, went to ask her husband. He however objected to the suitor on the grounds of personal appearance, and stipulated that he should at least first perform certain feats to prove his worthiness. The first task was to build a palace of pearls, the second to plant the highest mountain of Santorini (μέσο βουνί, ‘central mountain,’ as it is locally called) with trees, and the third to border all the roads of the island with flowers. For each labour one single night was the limit of time. But the ox-headed man was equal to the work, and having accomplished it came riding on a white horse to claim his bride. The king however, who had imposed these three labours in full assurance that the unseemly suitor would fail, now flatly refused to abide by his promise, and the man retired disconsolate and disappeared none knew whither.