O.T. Oss and O.N. Oeric were pseudonyms of brothers Dennis and Terence McKenna. Their book was the outgrowth of their experiments with Psilocybe cubensis cultivation on sterilized rye berries using James Sinden’s grain spawn methods. As the brothers discovered, this species grew and fruited quite happily from rye, especially when a sterile casing layer à la Falconer was applied atop the colonized grain. In their method, spores were germinated on a sterile agar medium and the resulting mycelium was transferred onto sterilized rye grain in quart canning jars. The casing layer was added directly to the colonized jar cultures, and fruiting would commence several weeks later. The relative simplicity of their method, with its reliance upon the use of more or less readily available ingredients and tools, along with the book’s quirky aesthetics and psychedelic, sci-fi musings, served to give it wide appeal, and spread the mushroom and its message far and wide.