the middle ages might have chosen for his solitude. The two walked briskly
across it, and at length came to a low, broad yawning opening, branching
out into several passages which, if pursued, would have been found to end
in nothing. Aspar, however, made straight for what appeared a dead wall of
rock, in which, on his making a signal, a door, skilfully hidden, was
opened from within, and was shut behind them by the porter. They now stood
in a gallery running into the mountain. It was very long, and a stream of
cold air came along it. Aspar told him that at the extremity of it they
should find Caecilius.

Agellius was indeed in the vestibule of a remarkable specimen of those
caves which had been used for religious purposes, first by the aborigines
of the country, then by the Phoenician colonists, and in the centuries
which had just passed, for the concealment of the Christians. The passage
along which they were proceeding might itself be fitly called a cave, but
still it was only one of several natural subterraneans, of different
shapes, and opening into each other. Some of them lay along the face of a
ravine, from which they received light and air; and here in one place
there were indications of a fortified front. They were perfectly dry,
though the water had at some remote period filtered through the roof, and
had formed pendants and pillars of semi-transparent stalactite, of great
beauty. It was another and singular advantage that a particular spot in
one of the caverns, which bordered on the ravine, was the focus of an
immense ear or whispering-gallery, such, that whatever took place in the
public road in which the ravine terminated, could be distinctly heard
there, and thus they were always kept on guard against the attack of an
enemy, if expected. Had either Agellius or Aspar been curious about such a
matter, the latter might have pointed out the place where a Punic altar
once had been discovered, with a sort of _tumulus_ of bones of mice near
at hand, that animal coming into the list of victims in the Phoenician
worship.

But the two Christians were engaged, as they first halted, and then walked
along the corridor, in other thoughts, than in asking and answering
questions about the history of the place of refuge in which they found
themselves. We have already remarked on the central position of Sicca for
the purpose of missionary work and of retreat in persecution; such a
dwelling in the rocks did but increase i