The rigid square is found only at an early stage in the development of composition. Moreover, all the examples are "story" pictures, for the most part scenes from the lives of the saints, etc. Many of them are double-centre,--square, that is, with a slight break in the middle, the grouping purely logical, to bring out the relations of the characters. Thus, in the "Dream of Saint Martin," Simone Martini, a fresco at Assisi, the saint lies straight across the picture with his head in one corner. Behind him on one side stand the Christ and angels, grouped closely together, their heads on the same level. These are all, of course, in one sense symmetrical,-- in the weight of interest, at least,--but they are completely amorphous from an aesthetic point of view. The forms, that is, do not count at all,--only the meanings. The story is told by a clear separation of the parts, and as, in most stories, there are two principal actors, it merely happens that they fall into the two sides of the picture. On the other hand, a rigid geometrical symmetry is also characteristic of early composition, and these two facts seem to contradict each other. But it is to be noted, first, that the rigid geometrical symmetry belongs only to the "Madonna Enthroned," and general "Adoration" pieces; and secondly, that this very rigidity of symmetry in details can coexist with variations which destroy balance. Thus, in a "Madonna Enthroned" of Giotto, where absolute symmetry in detail is kept, the Child sits far out on the right knee of the Madonna.