It must be allowed that these two gods taken together supply parallels to Janus’ most salient characteristics; and even to one or two of the less prominent and more puzzling ones, such as the connexion with springs[1266]. It is not impossible that all three may have grown out of a common root; but in the cases of Cernunnos and Heimdal it does not seem any longer possible to trace this, owing to heavy incrustations of poetical mythology. In the case of the Roman, the chance is a better one, in spite of philosophical speculation, ancient and modern. We return from philosophers and mythologists to early Rome. The one fact on which we must fix our attention is that on the north-east of the forum Romanum was the famous Janus geminus, which from representations on coins[1267] we can see was not a temple, but a gateway, with entrance and exit connected by walls, within which was, we may suppose, the double-headed figure of Janus which is familiar on Roman coins. The same word janus is applied to the gate and to the numen who guarded it, lived in it, and was as inseparable from it as Vesta from the fire on the hearth[1268]. The word does not seem to have been used for the gate of a city, but for the point of passage into a space within a city, such as a market, or a street. At Rome there were several such jani[1269]; probably two or more leading into the forum, as well as the more famous one, which alone appears to have had a strictly religious signification[1270]. The connexion of the god with entrances is thus a certainty, though we are puzzled by his apparent absence from the gates of the city[1271]. The double head would signify nothing transcendental, but simply that the numen of the entrance to house or market was concerned both with entrance and exit. It is not peculiar to Italy, or to Janus, but is found on coins in every part of the Mediterranean (Roscher, _Lex_. 53 foll.): in no case, it is worth noting, does the double head represent any of the great gods of heaven, such as Zeus, Apollo, &c., but Dionysus, Boreas, Argos, unknown female heads[1272], &c. Its history does not seem to have been worked out; but we can be almost sure that it does not represent the sun, and has no relation to the arch of heaven.