The details of the ornamental patterns in the MSS. will be dealt with when we come to consider the leading characteristics of the style; all that we need do now, therefore, is to point out the manner in which the patterns are distributed. The treatment of the miniatures of the Evangelists and of the scenes from the Life of Christ and the Life of David is very simple; the picture is enclosed within a rectangular frame divided into panels, each filled in with a separate piece of ornament complete in itself. Sometimes, as in the case of the miniatures of Christ seized by the Jews in the Book of Kells, and David playing the harp in the Vesp. A. i. Psalter, the figures are placed beneath an arch supported by columns at each side. The architectural origin of the design is entirely concealed by converting the columns and the arch into pieces of flat ornament arranged in panels. The pages of Eusebian Canons are also treated architecturally, the tables being placed under arcading so disguised by the incrustations of ornament as to be almost unrecognisable. The initial pages of the Gospels are only partially surrounded by a rectangular frame, so as to allow the tops of the large capital letters to project beyond the frame into the margin. The incomplete portion of the frame on the right side of the page is converted into a zoömorph in a characteristically Celtic manner by adding the head of a monster at the top and a fish-like tail at the bottom. The frame and the larger initials within it are covered with panels of ornament. The pages of ornament are generally arranged in rectangular panels, so as to give the appearance of a cross; or sometimes, as in the Book of Durrow, there is a small equal-armed cross within a circle in the middle of the page, the remainder of which is entirely filled up with ornament. In many cases where the miniatures, etc., are surrounded by a rectangular frame the outer margins are extended and formed into ornamental knots at each of the four corners. After the Celtic style of decorative art of the Christian period had been fully developed in the Irish and Hiberno-Saxon illuminated MSS. of the eighth century, it was afterwards applied to sculptured stonework in the ninth, tenth, and eleventh centuries. There are so few details of pre-Norman Celtic buildings[364] which afford examples of ornamental sculpture that they are hardly worth considering, so that we need only take cognisance of the sepulchral and other monuments. These are of the following different kinds:— (1) Recumbent cross-slabs. (2) Recumbent hog-backed and coped stones. (3) Erect cross-slabs. (4) Erect wheel-crosses. (5) Erect free-standing crosses. (6) Erect pillar crosses, with shafts of round or square cross-section. [364] The sculptured architectural details of the Round Towers and early churches in Ireland and Scotland consist chiefly of crosses or crucifixes over the doorways and terminal heads.