_Orcagna_ (part of the altar-piece, 569).
One may notice here one of Orcagna's limitations. "He was unable to
draw the nude. On this inability followed a coldness to the value of
flowing lines, and to the power of unity in composition; neither could
he indicate motion or buoyancy in flying or floating figures" (_On the
Old Road_, i. § 78). Compare especially the flying angels in the two
little pictures 571 and 572, with such figures as those by Botticelli
(1034), and it will be seen at once how inferior Orcagna's knowledge
was.