In the adjoining area, and belonging probably to the same date, is a very curious fresco, much damaged by having been cut through for the sake of making a grave behind it, yet still easily distinguishable in all its main features. The Good Shepherd occupies the centre of the painting. On either side is an apostle, probably SS. Peter and Paul, hastening away from Christ, Who has sent them to go and teach all nations. These are represented by two sheep standing before each of the apostles; and over their heads hangs a rock, whence pour down streams of water, which the apostles are receiving in their hands and turning on the heads of the sheep. We need no special explanation of this; we have already learnt that the Rock is Christ, and that the waters represent all Christian graces and sacraments. But what is worth noticing in this picture is the various attitudes of the sheep, and the corresponding distribution of the water. A perfect torrent is falling on the animal that stands with outstretched neck and head uplifted, drinking in all he hears with simplicity and eagerness; whilst another, which has turned its back upon the apostle, is left without any water at all. Of the other two, one is standing with head downcast, as if in doubt and perplexity, and upon him too grace is still being poured out more abundantly than upon the fourth, which is eating grass, _i.e._, occupied with the affairs of this world. On the right hand side of this _arcosolium_ are two representations of Moses; in the one he is striking the rock, and one of the Jews is catching some of the water which gushes forth; in the other he is taking off his shoes, preparing to obey the summons of God, who is represented by a hand coming forth from the cloud. The painting on the other side of the _arcosolium_ is even more defaced than that in the centre. A large semi-circular recess has been cut through it, and then the smoke of the lamp which burnt in this recess during the fourth and fifth centuries has almost obliterated the little that remained of the figure of our Lord. He stood between two of His apostles, who are offering Him bread and fish, and six baskets of loaves stand on the ground before them. And now we will not linger any more upon the road, but follow our guide, who hurries forward along the intricate passages until he lands us at last in an irregularly shaped space, illuminated by a _luminare_, decorated with paintings, and bearing manifest tokens of having been once a great centre of devotion. There is the pillar to support the usual vessel of oil or more precious unguents to be burnt before the tomb of the martyr; and hard by is a gravestone let into the wall with the words CORNELIUS MARTYR, EP.