Comparative study of the illuminated manuscripts of the same period shows exactly the same changes in progress. So closely do the two arts keep pace with each other that I do not think it can be said that at any time either was leading the other. They must have been in very close touch even if they were not, which it is quite possible they often were, practised by the same artists. The lead, if there was a lead, must have come from sculpture. [Sidenote: Natural plant forms in ornament.] (6) _The use of Natural Plant Forms in Ornament._--This is another manifestation of the same spirit, and divides the work of the fourteenth century most sharply from that both of the preceding and following periods. The Jesse Trees, and the leafy scrolls and borders of the twelfth and thirteenth centuries belong to no genus known to botanists, but in the fourteenth century it seems as if the artist, the inspiration of religion failing him, had sought it in a rather literal study of Nature. Accordingly in the grisaille and borders of this period we find patterns formed of oak leaves and acorns, ivy leaves, maple, vine, and so on. Plate XXVI. is rather an exception in that one cannot name the particular plant; but Plates XXVIII. and XXIX. contain characteristic examples, and Plate XXI. shows a good vine border from York, and some holly leaf grisaille. Yet the feeling for Nature in these patterns does not go very deep. The artist is, for instance, content to make the oak wreath and twine itself as freely as the vine, and I always feel that his practice is the result of theory rather than the spontaneous expression of love of Nature. The earlier worker was really, I believe, more in tune with Nature than his successor of the fourteenth century. He did not copy her forms in ornament but he followed her principles. He did not copy her forms, because she had taught him to design forms for himself. Nature, it may be observed, does not adorn one object with copies of another, hardly even when she gives her creatures protective colouring and markings, but gives to each the patterning which suits it best. In the same way the ornament of the twelfth and thirteenth century artist is always perfectly suited to its purpose without distracting one's attention; and when his subject requires him to represent a tree or a bush,--such as the fig tree under which Nathanael sits, or the thicket in which the ram is caught, at Canterbury,--though the foliage is that of the shamrock, he knows how to make it grow and live better than his fourteenth century successor. The waves, too, of the Flood in Plate IV., conventional though they are, give a real sense of tossing and stormy water. [Sidenote: Change in material.] [Sidenote: Fourteenth century colour schemes.]