From this peculiarity there followed many changes in style almost unknown abroad. The use of the depressed arch in the vault soon led to its adoption in the clerestory windows placed under the vault, and from these it spread to the other windows, and ultimately to all the arches of the building. From these features a perpendicular structure is at once recognisable. The panelling of the vaults led, in sympathy, to panelling in the wall surfaces, in the buttresses, and everywhere. A linear system of ornamentation was thus produced, which was developed to an extreme degree--the mouldings were thinned off till they became mere strings, with wide shallow hollows between, and all interruption to the stringy or liney effect thus produced was objected to. Thus the caps of shafts were almost abolished, and the thin arch mouldings carried down the piers without interruption from the arch to the base. The piers were divided up with large shallow hollows or splays, and the subordination of mouldings was lost. When caps were used they were generally small and octagonal in shape, and stood meaningless amidst a cluster of mouldings. Doorways were less deeply recessed than formerly, and the four-centred arch was usually enclosed in a square moulding, the spandrils between the square head and the arch being filled with tracery or sculpture, often of a heraldic nature. In France the two-centred arch was adhered to, and traceried windows were frequently introduced over doorways. Some of the carving, both at home and in France, is executed with great delicacy and spirit, but much of the foliage is of a very conventional form peculiar to the period. In running ornaments the stems frequently become more important than the leaves, thus carrying out the thin linear character of the style. The English architects always showed a fondness for wooden roofs, and at this the latest period of Gothic these open timber constructions became very common. In France, on the contrary, vaulted roofs were preferred till the revival of classic art. THIRD OR LATE POINTED STYLE IN SCOTLAND. During the latter part of the fifteenth and in the sixteenth centuries the erection of cathedrals and monasteries in Scotland was almost entirely superseded by collegiate churches. These structures are generally designed on a cruciform plan, with a central tower over the crossing. They have usually a porch at the south-west and a sacristy at the north-east angle, and occasionally one or more chantry chapels attached. Except in the larger examples of collegiate churches, such as St. Giles’ and Trinity College, Edinburgh, aisles are rarely introduced, and groined vaulting, although used in the above structures, is also uncommon. The churches are generally covered with pointed barrel vaults, for the most part plain, but sometimes ornamented with ribs applied to the barrel surface. The latter style of decoration is sometimes employed in the vaulting over the