ca, either with clearstory
windows, as in S. Demetrius, or without such windows, as in Eski Juma
Jamissi.

[Illustration: PLATE IX.
(1) S. JOHN OF THE STUDION. EAST END.
_E. M. Antoniadi._
(2) S. JOHN OF THE STUDION, NORTH SIDE, EAST END.
_To face page 52._]

The nave terminates in a large apse, semicircular within and showing
three sides on the exterior. Only the lower part is original; the
Turkish superstructure is lower and on a smaller scale than the
Byzantine portion it has replaced. There are no side chapels. Under the
bema the Russian explorers discovered a small cruciform crypt. The large
quantity of mosaic cubes found in the church during the recent Russian
excavations proves that the church was decorated with mosaics, while the
remains of iron plugs in the western wall for holding marble slabs show
that the building had the customary marble revetment. But what is
curious is to find the mortar pressed over the face of the stones, and
broad decorative joints formed by ruled incised lines and colour. Mr. W.
S. George suggests that this was a temporary decoration executed pending
some delay in the covering of the walls with marble. He also thinks that
the importance given to the joint in late Byzantine work and in Turkish
work may be a development from such early treatment of mortar.

The floor of the church was paved with pieces of marble arranged in
beautiful patterns, in which figures of animals and scenes from classic
mythology were inlaid. Gerlach[77] noticed the beauty of the pavement,
and Salzenberg[78] represents a portion of it in his work on S. Sophia.
But the members of the Russian Institute of Constantinople have had the
good fortune to bring the whole pavement to light.

A noticeable feature is the number of doors to the church, as in S.
Irene. Besides the five doors already mentioned, leading into the
interior from the narthex, there is a door at the eastern end of each
aisle, and close to each of these doors is found both in the southern
and northern walls of the building an additional door surmounted by a
window. The latter doors and their windows have been walled up.

The exterior is in two stories, corresponding to the ground floor and
the galleries. It has two ranges of eight large semicircular-headed
windows in the northern and southern walls, some of them modified,
others built up, since the building became a mosque. The five windows in
the gable of the western wall are, like