The plants known under the names of ayahuasca, peyotl and yage have three things in common. When consumed in suitable quantity they evoke visual hallucinations of astonishing clarity and brilliance of colour, and usually of a pleasing nature. Secondly,because of this property they are revered by the Indians of the regions in which they grow, and have a central place in their religious ceremonies. Thirdly,and this is the reason for writing of them here, they are supposed to produce clairvoyant, telepathic and precognitive powers in persons consuming them. The use of peyotl for this purpose in Mexico is mentioned by several early Spanish writers. Similar general statements regarding ayahuasca and yage could be given, but it is difficult of finding detailed accounts of specific instances. There is little or no evidence of the property of inducing paranormal powers that reaches the standard required by the Society for Psychical Research for printing as evidential. The two or three instances quoted below do no more than establish a prima facie case for further investigation.