At Ladykirk, the unusual form of elliptical windows is introduced, probably in order to admit as much light as possible at the haunches. As above explained, there are generally no aisles, and the windows, being kept down below the springing of the main arch, are, as usual, low, and here leave on the exterior a high space of blank wall above them. The above form of construction does not require or admit of a triforium and clerestory. At Rosslyn, where there are side aisles, the side walls of the choir are carried up so as to permit of clerestory windows. The tracery is almost always set in the centre of the wall, and the same mouldings, usually double chamfers, are repeated in the reveal both on the inside and outside. Where the choir, nave, and transepts have square ends, there is generally a large traceried window carried up in the gable under the barrel vault of the roof, by which the principal light in the church is obtained. The details of the late pointed churches in Scotland have comparatively little connection with the late work either in England or France, but some signs exist of importations from both these countries. At Melrose Abbey, Linlithgow Church and Palace, and a few other places, there are distinct indications of the influence of the perpendicular style of England; while the French influence is traceable in the apsidal terminations of the choir and occasionally of the transepts, and in some approaches to Flamboyant tracery. The latter influence may probably have also led to the crown-like terminations of some of the church towers. On the whole, however, it will be found that the details of the Scottish late pointed period are peculiar to itself, and are principally founded on survivals and revivals of details of the earlier styles. The doorways, for instance, are generally of the old, round-headed form, with late foliage and enrichments. The common English perpendicular doorway, with four-centred arch enclosed in a square frame, is never met with; and although elliptical or three-centred arches occur over doorways and windows, the four-centred arch-head is never used. Fan tracery vaulting is also entirely absent in Scotland. Porches to doorways are occasionally introduced, as at Aberdeen Cathedral and Whitekirk; and smaller porches are formed by arches thrown between buttresses, as at Rosslyn and Trinity College Churches. Coats of arms are very commonly carved on shields at this period, and are often useful in determining the dates of portions of the buildings, monuments, &c.