The consequences of the conversion of Constantine exhibited themselves not more in the internal character and spirit of the Church than in its outward forms and arrangements.  The period of worldly prosperity succeeded speedily to a period of severest suffering, and many who had been exposed to the persecution of Diocletian now rejoiced in the imperial favor shown to their religion.  Such contrasts in life are not favorable to the growth of the finer spiritual qualities; and the sunshine of state and court is not that which is needed for quickening faith or developing simplicity and purity of heart.  Churches above ground could now be frequented without risk, and were the means by which the wealth and the piety of Christians were to be displayed.  The newly imperialized religion must have its imperial temples, and the little dark chapels of the catacombs were exchanged for the vast and ornamental spaces of the new basilicas.  It was no longer needful that the dead should be laid in the secret paths of the rock, and the luxury of magnificent Christian tombs began to rival that of the sepulchres of the earlier Romans.  The body of St. Peter, which had long, according to popular tradition, rested in the catacombs of the Vatican, was now transferred to the great basilica which Constantine, despoiling for the purpose the tomb of Hadrian of its marbles, erected over the entrance to the underground cemetery.  So, too, the Basilica of St. Paul, on the way to Ostia, was built over his old grave; and the Catacombs of St. Agnes were marked by a beautiful church in honor of the Saint, built in part beneath the soil, that its pavement might be on a level with the upper story of the catacombs and the faithful might enter them from the church.

The older catacombs, whose narrow graves had been filled during the last quarter of the third century with the bodies of many new martyrs, were now less used for the purposes of burial, and more for those of worship.  New chapels were hollowed out in their walls; new paintings adorned the brown rock; the bodies of martyrs were often removed from their original graves to new and more elaborate tombs; the entrances to the cemeteries were no longer concealed, but new and ampler ones were made; new stairways, lined with marble, led down to the streets beneath; luminaria, or passages for light and air, were opened from the surface of the ground to the most frequented places; and at almost every entrance a church or an oratory of more or less size was built, for the shelter of those who might assemble to go down into the catacombs, and for the performance of the sacred services upon ground hallowed by so many sacred memories.  The worship of the saints began to take form, at first, in simple, natural, and pious ways, in the fourth century; and as it grew stronger and stronger with the continually increasing predominance of the material element in the Roman Church, so the catacombs, the burial-places of the saints, were more