A form of sympathetic magic which is practised by agricultural peoples all over the world is a "sacred marriage," whereby two spirits or their images, or their living representatives, are united, in order that their union may be sympathetically followed by fertility in flock and field. The ceremony of the "sacred marriage" frequently survives when its purpose has been forgotten, and then a popular explanation is invented for and by the folk. The myth of Acca Larentia, given by Plutarch, _R. Q._ 35, seems to me a piece of folk-lore of this kind. To begin with, it is not uncommon to find in Greek and Asiatic cults, for instance,[88] a woman shut up with a god in his temple. And the result of this union is an increase in the agricultural wealth or fertility of the community. The same result appears in the "rationalised" explanation of the "sacred marriage" of Acca Larentia and Hercules, given by Plutarch. Further, an exactly similar tale is told of Hercules and Flora,[89] whose name shows that she is a spirit of flowering and blossoming vegetation, whilst her cult points to a realistic sacred marriage in which she took part.[90] Again, Acca Larentia and Flora were evidently felt to be spirits of the same class as the Dea Dia, for sacrifices were offered to them as part of the worship of the Dea Dia; and the Dea Dia was a corn-spirit, as is plainly shown by the _Acta Arvalium Fratrum_.[91] At the same time, though Acca Larentia, Flora, and the Dea Dia were all spirits of the same class, it is clear that they were distinguished from each other, for the Arval Brothers sacrificed to each of them separately and under distinct names. Finally, whether Acca Larentia had originally anything to do with the Lares seems doubtful,[92] and in spite of the fact that, in later times at any rate, she was called "the mother of the Lares," one cannot build much on the etymology which makes "Acca" mean "mother."[93] Certain it is, however, that the Arval Brothers, in worshipping the Dea Dia, began their famous and very ancient song with an invocation of the Lares.[94] It is plain, therefore, that there was from pre-historic times a tendency to associate the worship of the kindly Lares with that of spirits of the class to which the Dea Dia and Acca Larentia belonged. But the feast of the Larentalia (or Larentinalia), to which Plutarch alludes in _R. Q._ 34, was evidently a piece of ancestor-worship, and may therefore have been part of the worship of the Lares from the beginning. If this really be so, Acca Larentia will be a soul promoted to the rank of a spirit of vegetation. The theory of sympathetic magic may perhaps afford the solution of Plutarch's problem (97), why they that would live chaste were forbidden to eat pulse. Plutarch suggests that as far as beans are concerned the reason may be that the Pythagoreans abominated them. This "symbol" of the Pythagoreans is well-known. Milton was inspired by it to put the case—