But towards the end of the third century three lowly wayfarers were journeying from Rome along the great southern road to Paris, charged by the Pope with a mission fraught with greater issues to Gaul than the Cæsars and all their legions. Let us recall somewhat of the appearance of the city which Dionysius, Rusticus and Eleutherius saw as they neared its suburbs and came down what is now known as the Rue St. Jacques. After passing the arches of the aqueduct, two of which exist to this day, that crossed the valley of Arcueil and brought the waters of Rungis,[8] Paray and Montjean to the baths of the imperial palace, they would discern on the hill of Lutetius to their right the Roman camp, garrison and cemetery. Lower down on its eastern slopes they would catch a glimpse of a great amphitheatre, capable of accommodating 10,000 spectators, part of which was laid bare in 1869 by some excavations made for the Campagnie des Omnibus between the Rues Monge and Linné. Unhappily, the public subscription initiated by the Académie des Inscriptions to purchase the property proved inadequate, and the Company retained possession of the land. In 1883, however, other excavations were undertaken in the Rue de Navarre, which resulted in the discovery of the old aqueduct that drained the amphitheatre, and some other remains, which have been preserved and made into a public park. [Illustration: REMAINS OF ROMAN AMPHITHEATRE.] On their left, where now stands the Lycée St. Louis, would be the theatre of Lutetia, and further on the imposing and magnificent palace of the Cæsars, with its gardens sloping down to the Seine. The turbulent little stream of the Bièvre flowed by the foot of Mons Lutetius on the east, entering the main river opposite the eastern limit of the _civitas_ of Lutetia, gleaming white before them and girdled by Aurelian's wall[9] and the waters of the Seine. A narrow eel-shaped island, subsequently known as the Isle de Galilée,[10] lay between the Isle of the Cité and the southern bank; two islands, the Isles de Notre Dame and des Vaches, divided by a narrow channel to the east, and two small islets, the Isles des Juifs and de Bussy, to the west. Another islet, the Isle de Louviers, lay near the northern bank beyond the two eastern islands. Crossing a wooden bridge, where now stands the Petit Pont, they would enter the forum (Place du Parvis Notre Dame) under a triumphal arch. Here would be the very foyer of the city; a little way to the left the governor's palace and the basilica, or hall of justice;[11] to the right the temple of Jupiter. As they crossed the island they would find it linked to the northern bank by another wooden bridge, replaced by the present Pont Notre Dame.[12] In the distance to the north stood Mons Martis (Montmartre) crowned with the temples of Mars and Mercury, four of whose columns are preserved in the church of St. Pierre; and to the west the aqueduct from Passy bringing its waters