[Sidenote: Egeria at Nemi a nymph of water and of the oak, perhaps a form of Diana.] From the foregoing survey of custom and legend we may infer that the sacred marriage of the powers both of vegetation and of water has been celebrated by many peoples for the sake of promoting the fertility of the earth, on which the life of animals and men ultimately depends, and that in such rites the part of the divine bridegroom or bride is often sustained by a man or woman. The evidence may, therefore, lend some countenance to the conjecture that in the sacred grove at Nemi, where the powers of vegetation and of water manifested themselves in the fair forms of shady woods, tumbling cascades, and glassy lake, a marriage like that of our King and Queen of May was annually celebrated between the mortal King of the Wood and the immortal Queen of the Wood, Diana. In this connexion an important figure in the grove was the water-nymph Egeria, who was worshipped by pregnant women because she, like Diana, could grant them an easy delivery.[540] From this it seems fairly safe to conclude that, like many other springs, the water of Egeria was credited with a power of facilitating conception as well as delivery. The votive offerings found on the spot, which clearly refer to the begetting of children,[541] may possibly have been dedicated to Egeria rather than to Diana, or perhaps we should rather say that the water-nymph Egeria is only another form of the great nature-goddess Diana herself, the mistress of sounding rivers as well as of umbrageous woods,[542] who had her home by the lake and her mirror in its calm waters, and whose Greek counterpart Artemis loved to haunt meres and springs.[543] The identification of Egeria with Diana is confirmed by a statement of Plutarch that Egeria was one of the oak-nymphs[544] whom the Romans believed to preside over every green oak-grove;[545] for while Diana was a goddess of the woodlands in general she appears to have been intimately associated with oaks in particular, especially at her sacred grove of Nemi.[546] Perhaps, then, Egeria was the fairy of a spring that flowed from the roots of a sacred oak. Such a spring is said to have gushed from the foot of the great oak at Dodona, and from its murmurous flow the priestess drew oracles.[547] Among the Greeks a draught of water from certain sacred springs or wells was supposed to confer prophetic powers.[548] This would explain the more than mortal wisdom with which, according to tradition, Egeria inspired her royal husband or lover Numa.[549] When we remember how very often in early society the king is held responsible for the fall of rain and the fruitfulness of the earth, it seems hardly rash to conjecture that in the legend of the nuptials of Numa and [Sidenote: The legend of the nuptials of Numa and Egeria may be a reminiscence of a sacred marriage which the kings of Rome contracted with a goddess of water and of