arrangement, which has apses in the aisle and a central apse, the only example is that of the cathedral of Autun. In Rouen cathedral, east of the transept aisles, there are apsidal chapels, which with the three chapels in the chevet make up the usual number. The Cathedral of St. Peter in Poitiers has been referred to as an example of a square east end, but a compromise has been made by the provision of three segmental apses, and there are no windows in the east front; the most remarkable divergence from the usual design is found here in the absence of any triforium or clerestory, because the vault of the aisles is nearly as high as that of the nave, so that it constitutes an example of what in Germany (where there are many) are called Hallenkirchen; the light being obtained through the aisle windows only gives a gloomy effect to the nave. Southern France Another departure from the usual plan is that found in Albi Cathedral (1350), in which there are no aisles, their place being taken by chapels between the buttresses which were required to resist the thrust of the nave vault, the widest in France. The cathedral is built in brick and externally has the appearance of a fortress. At the cathedrals in southwest France, where the naves are covered with a series of domes - as at St. Barthélemy in Saint-Étienne in Cahors, the cathedral of Angoulême and St. Front de Périgueux - the immense piers required to carry them made it necessary to dispense with aisles. The cathedral of Angouléme consists of a nave covered with three domes, a transept of great length with lofty towers over the north and south ends, and an apsidal choir with four chevet chapels. In St. Front de Périgueux (1150), based on St. Mark's at Venice, the plan consists of nave, transept and choir, all of equal dimensions, each of them, as well as the crossing, vaulted over with a dome, while originally there was a simple apsidal choir. Spain The cathedrals in Spain follow the same lines as those in France. The cathedral of Santiago de Compostela is virtually a copy of St Sernin at Toulouse, consisting of nave and aisles, transepts and aisles, and a choir with five chapels; at Leon there is a chevet with five apsidal chapels, and at Toledo an east end with