Rectilinear patterns are of comparatively rare occurrence in Late-Celtic art, as the designers of the period appear to have had a rooted objection to using straight lines if they could possibly be avoided. There are, however, a few exceptions. The small circular enamelled plaques with which the bronze shield from the Thames, now in the British Museum, is decorated, have a swastika pattern on each. The swastika was probably a foreign importation, as it is used in the decoration of the Gaulish bronze helmet from Gorge-Meillet[338] (Marne), and of the iron lance-head from La Tène,[339] Switzerland. The step-pattern in Late-Celtic art may have had a textile origin, _i.e_. have been copied from a woven belt or other fabric. Instances of it occur on a piece of engraved wood from the Glastonbury[340] Marsh Village; on the bronze mountings of a shield from Grimthorpe,[341] Yorkshire, now in the British Museum; on the bronze ferrule of a spear-shaft from the Crannog at Lisnacroghera,[342] Co. Antrim; and on a sculptured monolith at Turoe, Co. Galway. The step-pattern survived after the Pagan period in the Christian enamels, as in the bowl from Möklebust,[343] Norway, and the fragment at St. Columba’s College,[344] Dublin. The key-pattern, or Greek fret, is unknown in Late-Celtic art. The chequerwork pattern may also have had a textile origin. There is an example of it on the bronze sword-sheath from Embleton,[345] Cumberland, now in the British Museum. The chevron and lozenge patterns are possibly survivals from the preceding Bronze Age. We have instances of the chevron pattern on the bronze mirror from Trelan Bahow,[346] Cornwall, and on a potsherd from the Glastonbury[347] Marsh Village; and of the lozenge on the stave of a bucket[348] from the same site. [338] A. Bertrand’s _Archéologie Celtique et Gauloise_, p. 367. [339] E. Vouga’s _Les Helvètes à La Tène_, pl. 5. [340] _The Antiquary_ for 1895, p. 110. [341] Ll. Jewitt’s _Grave-Mounds and their Contents_, p. 246. [342] _Jour. R. Hist. and Archæol. Assoc. of Ireland_, ser. 4, vol. vi., p. 394. [343] _Mém. de la Soc. Ant. du Nord_, 1890, p. 35. [344] J. B. Waring’s _Manchester Fine Art Treasures Exhibition_. [345] Kemble’s _Horæ Ferales_, pl. 18, fig. 3. [346] _Archæol. Jour._, vol. xxx., p. 267. [347] _Proc. Somersetsh. Archæol. Soc._, vol. xl. [348] _The Antiquary_ for 1895, p. 110. [Illustration: Engraved Step Ornament on piece of wood found at the Glastonbury Lake Village Drawn by Arthur Bulleid, F.S.A.] CHAPTER VI CELTIC ART OF THE CHRISTIAN PERIOD (A.D. 450 to 1066) THE INTRODUCTION OF CHRISTIANITY INTO BRITAIN, AND ITS EFFECT ON NATIVE ART