Among the works belonging to the years before Fra Angelico went to San Marco, and painted the frescoes that stand for his middle period at its best, are the Altar-piece at Cortona, "The Annunciation" and "The Last Judgment," in the Academy of Florence, and the famous "Madonna da Linajuoli," with its twelve angels playing divers musical instruments on the frame round the central panel. These angels have made the Madonna of the Flax-workers the best known of all the painter's works. So long the delight of the public eye they are very harshly criticised to-day, and not without reason, for doubtless they are flat and stiff productions enough. But they have a certain naïve beauty of their own, and because they have done more than work of far greater merit to spread the fame of Fra Angelico, because they have been the source of great delight to countless people despised and rejected of art critics, it has seemed reasonable to present some of them in this little volume, side by side with those more important works of the master to which so many artists of the Renaissance are indebted. We may rest assured that to the painter the angels were very real angels indeed, the best that his art and devotion could express. [Illustration: PLATE IV.--CHRIST AS A PILGRIM MET BY TWO DOMINICANS This is a fresco in the cloister of San Marco at Florence. It will be seen that Christ holds a pilgrim's staff which cuts the picture in half, and the right hand of the foremost Dominican and the left hand of Christ, extended across the staff, form a cross.] Other important works of this first period, which may be taken to range from 1407 to 1435, are the altar-pieces known as the Madonna of Cortona, the Madonna of Perugia, and the Madonna of the Annelena, the last-named being in the Academy at Florence. Critics and artists can divide the painter's life into four or more divisions expressed to them by changes in his style; but a simpler division suffices here.