  Finally, physicians and philosophers created textual lineages and accounts of textual authority. The most important medical works of this kind are the Yellow Emperor’s Classic of Internal Medicine  and the Materia Medica of Shen Nong (Shen Nong bencao), ascribed to the “Divine Husbandmen” Shen Nong, who, according to legend, tested hundred of herbs and plants to ascertain their curative properties. By contrast, the evidence of recently excavated texts indicates that the Huang Di neijing derived from prior textual traditions that were subsequently lost (Harper 1998) and that the extant version is a composite of several earlier texts (Keegan 1988, Unschuld 2003, Unschuld and Tessenow 2011, Yamada 1979).