Few ever stop to look at the walls of the nave, and indeed, upon coming out of the sunlight, the darkness and gloom for some minutes is oppressive and but little can be distinguished in the gloom. It was almost by chance that we one day noticed some frescoes, ruined and faded, just outside the Chapel of St. Martin. They are of no beauty as works of art, indeed they are rather ugly, but their interest lies in showing us that from the very beginning artists had endeavoured, however feebly, to depict the legend of St. Francis.[68] On the left wall of the nave, outside the Chapel of St. Martin, is a fresco representing the Sermon to the Birds with the same idea of composition which was adopted later by Giotto; the saint slightly bends towards the birds upon the ground, his companion stands behind, while the single tree adds a certain solemnity to the scene. The figures are large and ungainly, with feet terrible to behold, the lines are hard, and there is little feeling of movement or life; yet we look at it with reverence and hope, for we know that, with all the ugliness and stiffness of workmanship, the artist was vehemently striving in this dark church to shake off the hampering chains of worn-out traditions, and find for himself something nearer to the truth. And as we look at this one and at the next, representing St. Francis receiving the Stigmata, our thoughts are carried to other renderings of these scenes, and we say with light hearts: "After this poor craftsman comes Giotto, King of Tuscan painters." These are the only two frescoes illustrating the life of the saint, though there may have been others which were destroyed when the walls of the nave were broken down in order to form entrances to the chapels, added to the main building about 1300. But on the right side, beginning outside the Chapel of San Stefano, are parts of several scenes from the New Testament; a crowd of women and men standing round the cross, a group of women, the Descent from the Cross, a Pietà, a landscape with houses and a decoration of circular ornaments outside the Capella di Sta. Maria Maddalena, generally attributed to Giunta Pisano, thus giving them too early a date.[69] To us their interest seems rather to lie in that they plainly show how the earliest masters, whilst endeavouring to illustrate the franciscan legend, failed so completely to satisfy their employers that they were bidden to stay their hand and continue to paint the well-worn theme of the history of the world's redemption, which required less invention than the legend of St. Francis, where a new out-look on life had to be acquired. So the franciscans, failing to find a painter who could illustrate their founder's life to their satisfaction, contented themselves with other things, perhaps hoping that in course of time one might arise who could do justice to the theme. Well it was that they waited.