In his paper Mr. Wasson summarizes his argument in favor of a mushroom, the fly-agaric called by mycologists Amanita muscaria, as the Soma of the Rig Veda. This mushroom was still being used as an inebriant by the shamans of remote tribes in Siberia only a few years ago. Mr. Wasson quotes from the Rig Veda to show how apposite are the poets' words to the fly-agaric, in most cases illustrating his points with colored plates. The Siberian tribesmen drink the urine of one who has taken the fly-agaric and find it as inebriating as the fly-agaric itself. Mr. Wasson raises the question whether the Vedic priests did not do likewise, marshalling certain evidence in favor of this view. He then explains how he thinks it happened that the identification of Soma has had to wait until now to be achieved, and finally he suggests certain textual cruces in the hymns that may be resolved by his discovery and outlines other channels of inquiry for fruitful research.