Of the cult of this day, apart from the extracts from the calendars, we know nothing, except that the heads of Roman families threw into the fire certain small fish with scales, which were to be had from the Tiber fishermen at the ‘area Volcani’[897]. We cannot explain this; but it reminds us of the fish called _maena_, with magical properties, which the old woman offered to Tacita and the ghost-world at the Parentalia[898]. Fish-sacrifices were rare; and if in one rite fish are used to propitiate the inhabitants of the underworld, they seem not inappropriate in another of which the object is apparently to propitiate the fire-god, who in a volcanic country like that of Rome must surely be a chthonic deity. The antiquity of the cult of Volcanus is shown by the fact that there was a Flamen Volcanalis[899], who on May 1 sacrificed to Maia, the equivalent, as we saw, of Bona Dea, Terra, &c. With Volcanus we may remember that Maia was coupled in the old prayer formula preserved by Gellius (13.23)—_Maia Volcani_. From these faint indications Preller[900] conjectured that the original notion of Volcanus was that of a favouring nature-spirit, perhaps of the warmth and fertilizing power of the earth. However this may be, in later times, under influences which can only be guessed at, he became a hostile fire-god, hard to keep under control. Of this aspect of him Wissowa has written concisely at the conclusion of his little treatise _de Feriis_. He suggests that the appearance of the nymphs[901] in the rites of this day indicates the use of water in conflagrations, and that Ops Opifera was perhaps invoked to protect her own storehouses. The name Volcanus became a poetical word for devouring fire as early as the time of Ennius, and is familiar to us in this sense in Virgil[902]. After the great fire at Rome in Nero’s time a new altar was erected to Volcanus by Domitian, at which (and at all Volcanalia) on this day a red calf and a boar were offered for sacrifice[903]. At Ostia the cult became celebrated; there was an ‘aedes’ and a ‘pontifex Volcani’ and a ‘praetor sacris Volcani faciundis.’ In August the storehouses at Ostia would be full of new grain arrived from Sicily, Africa, and Egypt, and in that hot month would be especially in danger from fire; an elaborate cult of Volcanus the fire-god was therefore at this place particularly desirable.