5
There is one puzzling circumstance in the cemetery of S. Domitilla. All the graves in this cemetery are arcosolia, and yet the date of construction is early. The Cavaliere de Rossi suggests that the cemetery was begun at the expense of the Domitilla whose name it bears, the niece of Domitian, previously to her banishment; that her position enabled her to have it laid out from the beginning on a regular plan, and to introduce this more expensive and elaborate form of grave, which was continued for the sake of uniformity in the later excavations.
6
These chapels are generally about ten feet square. Some are larger, and a few smaller than this.
7
Revelations, vi. 9-11. It seems probable that another custom of the Roman Church took its rise in the catacombs,that of burning candles on the altar; a custom simple in its origin, now turned into a form of superstition, and often abused to the profit of priests.