1. The theory that Janus was a sun-god has the support of Roman antiquarians[1258], and was probably suggested by them to the moderns. Nigidius Figulus, the Pythagorean mystic, seems to have been the first to broach the idea: we have no evidence that Varro gave his sanction to it. It was Nigidius who first suggested the idea of the relation of Janus to Diana (Dianus, Diana = Janus, Jana), which found much favour with Preller and Schwegler[1259] at a time when neither comparative philology nor comparative mythology were as well understood as now. But the common argument, both in ancient and modern times, has been that which Macrobius quotes from certain speculators whom he does not name: ‘Ianum quidam solem demonstrari volunt, et ideo geminum quasi utriusque ianuae coelestis potentem, qui exoriens aperiat diem, occidens claudat,’ &c. It is obvious that this is pure speculation by a Roman of the cosmopolitan age: it is an attempt to explain the Janus geminus as the representation of one of the great forces of nature. But it has nothing to do with the ideas of the early Italian farmer. 2. The theory that Janus was a god of the ‘vault of heaven’ was also started by the ancients, as may be seen from the chapter of Macrobius quoted above. Recently it has been adopted by Professor Deecke in his Etruscan researches[1260]. He seems to hold that Janus in Etruria, as a god of the arch of heaven, was represented on arches and gates in that country, and came to Rome when the Romans learnt the secret of the arch from the Etruscans. That the Romans were the pupils of the Etruscans in this particular seems to be true; but if Janus only came to Rome with the arch (Deecke says in Numa’s time) it is hard to see how he could have so quickly gained his peculiar place in Roman worship and legend. I cannot think that Deecke has here improved on the conclusions of his predecessor.