All must be performed not merely 'decently and in order,' but with the most scrupulous care alike for every detail of the ceremonial itself, and for the surrounding circumstances. The omission or misplacement of a single word in the formulae, the slightest sign of resistance on the part of the victim, any disorder among the bystanders, even the accidental squeak of a mouse, are sufficient to vitiate the whole ritual and necessitate its repetition from the very beginning. One of the main functions of the Roman priesthood was to preserve intact the tradition of formulae and ritual, and, when the magistrate offered sacrifice for the state, the _pontifex_ stood at his side and dictated (_praeire_) the formulae which he must use. Almost the oldest specimen of Latin which we now possess is the song of the Salii, the priests of Mars, handed on from generation to generation and repeated with scrupulous care, even though the priests themselves, as Quintilian assures us, had not the least notion what it meant. Nor was it merely the words of ceremonial which were of vital importance: other details must be attended to with equal exactness. Place, as we have seen, was an essential feature even in the conception of deity, and it must have required all the personal influence of Augustus and his entourage to reconcile the people of Rome, with the ancient home of the goddess still before their eyes, to the second shrine of Vesta within the limits of his palace on the Palatine. The choice of the appropriate offering again was a matter of the greatest moment and was dictated by a large number of considerations. The sex of the victim must correspond to the sex of the deity to whom it is offered, white beasts must be given to the gods of the upper world, black victims to the deities below. Mars at his October festival must have his horse, Iuno Caprotina her goat, and Robigus his dog, while in the more rustic festivals such as the Parilia, the offering would be the simpler gift of millet-cakes and bowls of milk: in the case of the Bona Dea we have the curious provision that if wine were used in the ceremonial, it must, as she was in origin a pastoral deity, always be spoken of as 'milk.' The persons who might be present in the various festivals were also rigidly determined: men were excluded from the Matronalia on March 1, from the Vestalia on the 9th of June, and from the night festival of the Bona Dea: the notorious escapade of Clodius in 62 B.C. shows the scandal raised by a breach of this rule even at the period when religious enthusiasm was at its lowest ebb. Slaves were specifically admitted to a share in certain festivals such as the Saturnalia and the Compitalia (the festival of the Lares), whereas at the Matralia (the festival of the matrons) a female slave was brought in with the express purpose of being significantly driven away.