the human figure has been the subject of drawings since prehistoric times. while the studio practices of the artists of antiquity are largely a matter of conjecture, that they often drew and modeled from nude models is suggested by the anatomical sophistication of their works. an anecdote related by pliny describes how zeuxis reviewed the young women of agrigentum naked before selecting five whose features he would combine in order to paint an ideal image. the use of nude models in the medieval artist's workshop is implied in the writings of cennino cennini, and a manuscript of villard de honnecourt confirms that sketching from life was an established practice in the 13th century. the carracci, who opened their "accademia degli incamminati" in bologna in the 1580s, set the pattern for later art schools by making life drawing the central discipline. the course of training began with the copying of engravings, then proceeded to drawing from plaster casts, after which the students were trained in drawing from the live model.