Giorgio Vasari, Lives of the Most Excellent Painters… (1850)
“ But, induced by Nature herself to the arts of design, he was perpetually drawing on the stones, the earth, or the sand, some natural object that came before him, or some fantasy that presented itself to his thoughts. It chanced one day that the affairs of Cimabue took him from Florence to Vespignano, when he perceived the young Giotto, who, while his sheep fed around him, was occupied in drawing one of them from the life, with a stone slightly pointed, upon a smooth clean piece of rock,—and that without any teaching whatever, but such as Nature herself had imparted. ”
