This paper reviews the publications by R. Gordon Wasson on the identification of the ancient Aryan entheogenic piant, soma. Eight major reviews of Wasson's well-known soma: Amanita muscaria theory are also discussed, along with Wasson's responses to two of these; and one serious challenge and fivee alternate proposals to his hypothesis are examined. Revised and enlarged version of a Castilian article (OTT 1994b).