The Middle Pointed passed by a gentle gradation into the Late Pointed style, and it is difficult to say when the one ceased and the other began. Yet there are some characteristics of the Third Pointed which are peculiar to it and render it a distinct epoch. The large churches are nearly all restorations, and no new churches of great size were undertaken. The Scottish churches are usually smaller in size than the English ones, and consist of single compartments without aisles. The east end frequently terminates with a three-sided apse--a feature which owes its origin to the Scottish alliance and intercourse with France. The leading and distinguishing feature is, however, the vaulting--the pointed barrel vault being almost universally employed. The windows of these churches are necessarily low, so as to allow the point of the arch-head to come beneath the spring of the main vault. The buttresses are generally somewhat stunted. The windows are almost always pointed, and contain simple tracery derived from the earlier styles. The doorways are generally of the old round-headed form, with late foliage and enrichments. Porches are occasionally introduced, and coats of arms are commonly carved on shields of the period, and are useful in determining the dates of portions of the buildings. Towers were generally erected or intended, and are somewhat stunted, finished with short spires, having small dormer windows inserted in them. Monuments are of frequent occurrence, and are frequently placed in arched and canopied recesses. Richly carved sacrament-houses are occasionally introduced, and perhaps some of the good carving may be due to the French masons who were numerous in Scotland during the reigns of James IV. and James V. The structures of the period were either parish or collegiate churches.[24] CHAPTER III 1. DIOCESE OF ST. ANDREWS