aisle for a sacristy, and set the respond on the west side of this narrow bay. Their north aisle thus consisted of five bays and a very narrow eastern bay for the sacristy. On the south side no space corresponding to the sacristy was marked out, although the eastern respond was placed in a line with the east side of the opening of the sacristy. The number of bays on the south side had to be five, as there was no room for six. The result is that the pillars of the arcades, with the exception of those of the two bays furthest west, which were left unaltered, are not opposite each other. In the meantime, the old transeptal chapel was left standing between a south aisle and a short south chapel of the chancel. About 1300, the aisle and chapel seem to have been widened to the full length of the transeptal chapel, and thus a broad south aisle was formed. In this plan, the chancel proper projects for some distance east of the aisles; but, for ritual purposes, the eastern part of the nave, corresponding to the eastern bay of the north aisle and the sacristy bay beyond, forms, and has formed since the twelfth century, a western extension of the chancel. Sec. 68. The addition of aisles to chancels was an even more gradual process than the addition of aisles to naves; and, as a rule, the aisles were at first mere chapels. Chancel aisles or chapels of twelfth century date are not very common in smaller churches. But a plan like that at Melbourne, where the apsidal chapels east of the transepts flank the chancel very closely, leads naturally to the provision of chapels communicating directly with the chancel. The logical consequence of such a plan is seen at Oundle, at the close of the twelfth century, where rectangular chapels were built along the north and south walls of the western part of the chancel. The walls were pierced with broad, low arches, and arches were built between the chapels and the transepts. The chapels, in this instance, are at the back of the quire stalls; and a long projecting piece of aisleless chancel was left beyond them, to which, in the fifteenth century, a large northern vestry was added. This plan, where both chancel chapels were added at much the same time and on the same scale, is symmetrical. But, as a rule, chancel chapels were built just when they were needed. At Arksey, near Doncaster, where, as at St Mary's, Shrewsbury, the walls of late twelfth century transepts have been largely preserved inside the church in spite of many alterations, the chancel is a long aisleless twelfth century building east of a central tower. Towards the end of the thirteenth century, the north chancel wall was pierced, and a narrow chapel built, which was one bay shorter than the chancel itself. In the fourteenth and fifteenth centuries the nave was enlarged, and the south aisle was widened to the full length of the south transept. A south chapel was added to the chancel: its outer wall was continued from the south wall of the