rst half of the third century. The original _schola_ was covered by
a wooden roof, and had no facade or door. In the year 258, while
Sixtus II., attended by his deacons Felicissimus and Agapetus, was
presiding over a meeting at this place in spite of the prohibition of
Valerian, a body of men invaded the _schola_, murdered the bishop and
his acolytes, and razed the building nearly to the level of the
ground. Half a century later, in the time of Constantine, it was
restored to its original shape, with the addition of a vaulted roof
and a facade. The line which separates the old foundations of Fabianus
from the restorations of the age of peace is clearly visible. Later
the _schola_ was changed into a church and dedicated to the memory of
Syxtus, who had lost his wife there, and of Caecilia, who was buried in
the crypt below. It became a great place of pilgrimage, and the
itineraries mention it as one of the leading stations on the Appian
Way.

When de Rossi first visited the place, fifty years ago, this famous
_schola_ or church of Syxtus and Caecilia was used as a wine-cellar,
while the crypts of Caecilia and Cornelius were used as vaults. Thanks
to his initiative the monument has again become the property of the
Church of Rome; and after a lapse of ten or twelve centuries divine
service was resumed in it on the twentieth day of April of the present
year. Its walls have been covered with inscriptions found in the
adjoining cemetery.

The theory suggested by modern writers with regard to the _scholae_ is
very much the same as that concerning the _tablinum_ of private
houses. At first the small building was sufficient to meet the wants
of a small congregation; with the increase of the members it became a
_presbiterium_, or place reserved for the bishop or the clergy, while
the audience stood outside, under the shelter of a tent, or a roof
supported by upright beams. Here also we have all the architectural
elements of the Christian basilica.

The name _schola_, in its original meaning, has never died out in
Rome; and as in the Middle Ages we had the _scholae_ of the Saxons, the
Greeks, the Frisians, and the Lombards, so we have in the present
day those of the Jews (_gli scoli degli ebrei_).

[Illustration: PLAN OF SCHOLA ABOVE THE CATACOMBS OF CALLIXTUS
(From Nortet's _Les Catacombes Romaines_)]

III. ORATORIES AND CHURCHES BUILT OVER THE TOMBS OF MARTYRS AND
CONFESSORS. The sacred buildings of this class are, or we