Numa Pompilius, the second of Rome's legendary kings, is said, as already mentioned, to have instituted the college of the Vestal Virgins and to have formulated the rules of the life to which they were bound. It seems probable, however, that the order was more ancient than even the city itself; reaching back, as has been indicated, to the prehistoric time when the ancestors of the Latin tribes migrated from the common Aryan home. At first the Roman Vestals were four in number, two for each of the original Roman tribes, the Ramnes and the Tities; after the addition of the Luceres, the number was increased to six. Maidens were made Vestals when between six and ten years of age. Whenever a vacancy occurred, the chief pontiff chose twenty girls from the patrician order, care being taken to select only those who were in perfect health, free from the least physical blemish, and showing promise of future beauty. Then the casting of lots was resorted to, in order that the goddess herself might have an opportunity to designate which of the number should be selected as her priestess. The maiden to whom fell this fortune gave her right hand to the pontiff, who said: "I take thee; thou shalt be priestess of Vesta, and shalt perform the sacred rites for the safety of the Roman people." Then the girl was conducted to the house of the sacred virgins, who cut off her hair and clothed her in the white robes of the order. The ceremony in many respects corresponded to that of the modern nun in taking the veil. The term of consecration was thirty years, thus giving the votaries ten years in which to learn their duties, ten for the practice of them as serving members, and ten in which they governed the order and enjoyed the highest honors in its gift. After thirty years, the Vestals were at liberty to return to their families, or to marry, if they so desired; but advantage was rarely taken of this permission, they preferring the service of the goddess to whom they had vowed their virginity.