The two days prior to initiation into the second and third degrees were spent by the candidates in solitary retirement and in strict fasting. It was a "retreat" in the strictest sense of the word. Fasting was practised, not only in imitation of the sufferings of Demeter when searching for Persephone, but because of the danger of the contact of holy things with unholy, the clean with the unclean. This also is one of the reasons why it was held to be impious even to speak of the Mysteries to one who had not been initiated and especially dangerous to allow such unclean and profane persons to take any part, even that of a viewer, in the ceremonies. Hence the punishment meted out by the State was in lieu of, or to avert, the divine wrath which such pollution might bring on the community at large. At the entrance to the temple tablets were placed containing a list of forbidden foods. The list included several kinds of fish--the whistle-fish, gurnet, crab, and mullet. In all probability the whistle-fish is that known as _Sciæna aquila_, a Mediterranean fish that makes a noise under the water which has been compared to bellowing, buzzing, purring, or whistling, the air bladder being the sound-producing organ. The fish was greatly esteemed by the Romans. There is a large _Sciæna_, not _aquila_, though very like it, in the Fish Gallery of the British Museum (Natural History) opposite the entrance from the Zoological Library. The whistle-fish and crab were held to be impure, the first because it laid its eggs through the mouth, and the second because it ate filth which other fish rejected. The gurnet was rejected because of its fecundity as witnessed in its annual triple laying of eggs, but, according to some writers, it was rejected because it ate a fish which was poisonous to mankind. It may well be that other fish were interdicted, but Porphyry was probably exaggerating when he said that all fish were forbidden. Birds bred at home, such as chickens and pigeons, were also on the banned list, as were beans and certain vegetables which were forbidden for a mystical reason which Pausanias said he dare not reveal save to the initiated. The probable reason was that they were connected in some way with the wanderings of Demeter. Pomegranates were, of course, forbidden, from the incident of the eating of the pomegranate seeds by Persephone.