The special tournament shield, the shield à bouche, had a marked influence on subsequent forms. In order that the shield might, during the joust, fit closely to the shaft of the lance a semi-circular opening was made, sometimes at the top but more usually at the side, as in the example (Fig. 22), and from this simple expedient a very great variety of shape resulted, of which the manner of evolution is interesting. In the ornamental forms that were based on the actual ones this embouchure was sometimes plainly indicated, as in the shield from the group of Dürer’s coat of arms (Fig. 23) and in the French wood-carving (Fig. 24); in others the lower point of the opening was merged into one swinging line, as in the shield of the well-known Death’s Head coat of arms. The next step was to duplicate the curve suggested by the bouche, and from the resulting form proceeded an endless variety of similar shapes, the addition of foliated or scroll ornament completing the transition from the practical shield to the ornamental one. An interesting instance of this duplication of form occurs in the shield from a fifteenth century monument in St. Gatien Cathedral (Fig. 25). With the recognition of the purely ornamental character of the shield-form the placing of the spear opening on the naturally correct side, the dexter, ceased to be thought important, and it was placed indifferently on one side or the other, and when such shields occur in pairs, as in those on the Pirckheimer bookplate by Dürer, the bouche-derived curves are placed symmetrically on opposite sides. [Illustration: FIG. 22.--Tournament Shield. Fifteenth Century.] [Illustration: FIG. 23.--Dürer’s Arms. Early Sixteenth Century.] [Illustration: FIG. 24.--French Wood-carving. Fifteenth Century.] [Illustration: FIG. 25.--Fifteenth Century.] [Illustration: FIG. 26.--1530.] Foliated decoration applied to the duplicated tournament form is well exemplified in the shield from the plate of the arms of Herr Kress, who was the friend of Dürer, though the plate is not Dürer’s work (Fig. 26). [Illustration: FIG. 27. FIG. 28. FIG. 29. FIG. 30. Shields by Aldegrever. 1552.] Among the work of Dürer’s school the beautiful plates of his pupil Hans Sebald Beham will well repay study for their excellent composition and for their extreme beauty of draughtsmanship and engraving. Beham’s shields were often scrolled at the edge, but not extravagantly so, and he frequently employed plain shields, which, like most others at the time, however plain in outline, were shown more or less concave in some or all directions: a well-known device to obtain relief for the light side of the charges by means of the adjacent shadow that is formed by the concavity of the shield.