"The emperor having employed himself in shooting from above ... descended afterwards to the bottom of the theatre, and there slew some other private beasts, whereof some made toward him, others were brought to him, and others were shut up in dens. Returning after dinner, he used the exercises of a gladiator, with a shield in his right hand, and in his left a wooden sword. After him fought those whom he had chosen in the morning at the bottom of the theatre." Also, in his life of Septimius Severus, he says: "There was a kind of cloister made in the amphitheatre, in the form of a ship, to receive them [the wild beasts]. On a sudden there issued out bears, lions, ostriches, wild asses, and foreign bulls." The walls before us are of very bad construction, evidently repairs of a late date: they are the work of either Lampridius, prefect of Rome under Valentinian III., 425-455, who repaired the steps and renewed the arena; or of Basilius, who restored the podium and arena after their destruction by an earthquake in 486--this we learn from two inscriptions standing at the entrance. Half way, on each side, two large passages have been discovered choked up with mud: they were the aqueducts to bring the water for the _naumachiæ_ from the reservoirs upon the Esquiline and Cælian Hills respectively; from the small openings in the blind arches the water also poured out over the top of the dens, thus forming cascades all round. At the end opposite the present entrance a long passage has been opened, above the level of the area floor; below this passage is the great drain, with the remains of the iron grating[6] to prevent large objects going down: this and the passage were closed by flood-gates on naval representations, which can be clearly seen in the construction. On the right and left of this passage, connected with it, but at a lower level, two dens have been cleared out, 27 yards long by 5 wide, containing six holes in the floor, in the centre of square blocks of stone, and these holes are faced with bronze, evidently the sockets into which metal posts were fixed to which the beasts were chained. On the fragments depicting scenes from the arena, the animals are shown with a long piece of rope or chain dangling from their necks, which seems to bear out our idea that they were attached to posts fixed in these sockets, and that as they were wanted the chain or rope was cut, and they were free to rush upon the arena.