The square and oval types, as is seen from the table, are far less often used.  The oval, most infrequent of all, appears only among the ‘active’ pictures, with the exception of landscape.  It usually serves to unite a group of people among whom there is no one especially striking—­or the object of whose attention is in the center of the picture, as in the case of the Descent from the Cross.  It imparts a certain amount of movement, but an equable and regular one, as the eye returns in an even sweep from one side to the other.

The square type, although only three per cent. of the whole number of pictures, suggests a point of view which has already been touched on in the section on Primitive Art.  The examples fall into two classes:  in the first, the straight lines across the picture are unrelieved by the suggestion of any other type; in the second, the pyramid or V is suggested in the background with more or less clearness by means of architecture or landscape.  In the first class are found, almost exclusively, early examples of Italian, Dutch and German art; in the second, pictures of a later period.  The rigid square, in short, 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-center—­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 (325), 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.  Compare also the Finding of the Cross, Piero della Francesca (1088), a serial picture in two parts, with their respective backgrounds all on the same level; and most of the frescoes by Giotto at Assisi—­in particular St. Francis before the Sultan (1057), in which the actors are divided into parties, so to speak.

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.  Interesting in connection with this is the observation that, although the more anecdotal the picture the more likely it is to be ‘double-centered,’ the later the picture the less likely it is to be double-centered.  Thus the square and the double-center composition seem often to be found in the same picture and to be, both, characteristic of early composition.  On the other hand, a rigid geometrical symmetry is also characteristic, and these two facts seem to contradict each other.