ter
which indicates their position. The church is cruciform, and the
choir is unusually short and the nave unusually long. The aisled
choir extends only two bays eastwards from the crossing, beyond
which point the presbytery is carried one bay farther, without
aisles, and is lighted by large north and south windows as well as
by the great eastern window.

The shortness of the choir rendered it necessary that part of the
nave should be appropriated for the monks, and the enclosing screen
wall of this portion of the "choir" extended to the fourth pier west
from the crossing, where it was carried across the nave and formed
the rood screen. The screen was wide and contained a gallery, on the
top of which stood the rood.[454] The nave extends to eight bays,
but it has been intended to be longer--the west end being
incomplete. Extending southwards, beyond the south aisle, is a
series of eight chapels, which produced externally, along with the
south aisle, the appearance of a double aisle.[455] The north aisle
is narrower than the south aisle, and the position of the cloister
may have hampered the design.

This difference may have arisen from the plan of the original abbey of
the twelfth century being adhered to in the later construction.[456]

The transepts contain the usual eastern aisle only, in which are
situated four chapels.

The superstructure of the church has severely suffered and the
western part is greatly demolished. The portion eastwards from the
rood screen is in better preservation. The vaulting of the aisles is
well-preserved, but that of the centre aisle is demolished--a
pointed tunnel vault having been constructed in 1618. The eight
chapels are well preserved, but some parts of the three furthest
west ones are damaged and have lost their vaulting. The tracery in
the chapel windows is lovely; the vaulting of the nave, south aisle
and chapels, is supported by a series of flying buttresses, "which
form one of the most prominent and beautiful elements of the
building. No church in Scotland retains such a striking example of
that important feature of Gothic architecture."[457]

The eastern piers of the crossing were demolished probably in Henry
VIII.'s time, and their destruction entailed that of the central
tower, of which the western wall only remains. The transepts have
s