Offprint from the Dec. 1963 issue of The Journal of Nervous and Mental Disease. First separate printing, one of a small number of copies for the author's use. Detailed early account of Leary's pioneering experiments with hallucinogenic mushrooms at Harvard. The first research where the drug was given in "comfortable home-like surroundings" rather than a clinical setting. One of the most important papers from the Harvard Psilocybin Project---preceding Leary's experimentation with LSD. A very scarce item that laid the groundwork for the Psychedelic Revolution that began a few years later. Fine.