The painters of the late thirteenth and early fourteenth century, developing the meagre suggestions of Byzantine decoration, incorporating the richer inventions of the bas-reliefs of the Pisan sculptors and of the medallions surrounding the earliest painted effigies of holy personages, produced a complete set of pictorial themes illustrative of Gospel history and of the lives of the principal saints. These illustrative themes--definite conceptions of situations and definite arrangements of figures--became forthwith the whole art's stock, universal and traditional; few variations were made from year to year and from master to master, and those variations resolved themselves continually back into the original type. And thus on, through the changes in artistic means and artistic ends, until the Italian schools disappeared finally before the schools of France and Flanders. Let us take a striking example. The presentation of the Virgin remains unaltered in main sentiment and significance of composition, despite the two centuries and more which separate the Gaddi from Titian and Tintoret, despite the complete change in artistic aims and methods separating still more completely the men of the fourteenth century from the men of the sixteenth. The long flight of steps stretching across the fresco in Santa Croce stretches also across the canvas of the great Venetians; and the little girl climbs up them alike, presenting her profile to the spectator; although at the top of the steps there is in one case a Gothic portal, and in the other a Palladian portico, and at the bottom of the steps in the fresco stand Florentines who might personally have known Dante, and at the bottom of the steps in the pictures the Venetian patrons of Aretino. Yet the presentation of the little maiden to the High Priest is quite equally conceivable in many other ways and from many other points of view. As regards both dramatic conception and pictorial composition, the moment might have been differently chosen; the child might still be with its parents or already with the priest; and the flight of steps might have been replaced by the court of the temple. Any man might have invented his own representation of the occurrence. But the men of the sixteenth century adhered scrupulously or indifferently to the inventions of the men of the fourteenth.