The following pages aim at presenting in brief compass a selection of the evidence upon which the hypothesis of thought transference, or telepathy, is based. Contents: experimental transference of simple sensations in the normal state; experimental transference of simple sensations with hypnotized percipients; experimental production of movements and other effects; experimental production of telepathic effects at a distance; general criticism of the evidence for spontaneous thought transference; transference of ideas and emotions; coincident dreams; hallucination in general; induced telepathic hallucinations; spontaneous telepathic hallucinations; collective hallucinations; some less common types of telepathic hallucination; clairvoyance in trance; clairvoyance in the normal state; theories and conclusions.