“Come, come along,” he said, “or we shall lose sight of the rest, and not see which way they turn. That little niche is to hold a lamp; you will find one at each angle. As to ourselves, we know every alley and turn here below, as you do those of the city above.” [Illustration: A Lamp with a representation of the Good Shepherd, found at Ostium prior to the third century. From Roller’s “Catacombes.”] Torquatus was somewhat reassured by this account of the lamps--those little earthen ones, evidently made on purpose for the catacombs, of which so many are there found. But not content, he kept as good count as he could of the turns, as they went; and now with one excuse, and now with another, he constantly stopped, and scrutinized particular spots and corners. But Severus had a lynx’s eye upon him, and allowed nothing to escape his attention. At last they entered a doorway, and found themselves in a square chamber, richly adorned with paintings. “What do you call this?” asked Tiburtius. “It is one of the many crypts, or _cubicula_,[101] which abound in our cemeteries,” answered Diogenes; “sometimes they are merely family sepultures, but generally they contain the tomb of some martyr, on whose anniversary we meet here. See that tomb opposite us, which, though flush with the wall, is arched over. That becomes, on such an occasion, the altar whereon the Divine mysteries are celebrated. You are of course aware of the custom of so performing them.” [Illustration: Cubiculum or Crypt, as found in the Catacombs.] “Perhaps my two friends,” interposed Pancratius, “so recently baptized, may not have heard it; but I know it well. It is surely one of the glorious privileges of martyrdom, to have the Lord’s sacred Body and precious Blood offered upon one’s ashes, and to repose thus under the very feet of God.[102] But let us see well the paintings all over this crypt.” [Illustration: The Last Supper. From a picture in the Cemetery of St. Callistus.] “It is on account of them that I brought you into this chamber, in preference to so many others in the cemetery. It is one of the most ancient, and contains a most complete series of pictures, from the remotest times down to some of my son’s doing.” “Well, then, Diogenes, explain them systematically to my friends,” said Pancratius. “I think I know most of them, but not all; and I shall be glad to hear you describe them.” “I am no scholar,” replied the old man, modestly, “but when one has lived sixty years, man and boy, among things, one gets to know them better than others, because one loves them more. All here have been fully initiated, I suppose?” he added, with a pause. “All,” answered Tiburtius, “though not so fully instructed as converts ordinarily are. Torquatus and myself have received the sacred gift.” [Illustration: A Ceiling in the Catacombs. From De Rossi’s “Roma Sotteranea.”]