_Hypnagogic._--_Illusions hypnagogiques_ (Maury) are the vivid illusions of sight or sound--"faces in the dark," etc.--which sometimes accompany the oncoming of sleep. To similar illusions accompanying the _departure_ of sleep, as when a dream-figure persists for a few moments into waking life, I have given the name _*hypnopompic_. _Hypnogenous zones._--Regions by pressure on which hypnosis is induced in some hysterical persons. _*Hypnopompic._--See _Hypnagogic_. _Hysteria._--"A disordered condition of the nervous system, the anatomical seat and nature of which are unknown to medical science, but of which the symptoms consist in well-marked and very varied disturbances of nerve-function" (_Ency. Brit._). Hysterical affections are not dependent on any discoverable lesion. _Hysterogenous zones._--Points or tracts on the skin of a hysterical person, pressure on which will induce a hysterical attack. _Ideational._--Used of impressions which display some distinct notion, but not of sensory nature. _Induced._--Of hallucinations, etc., intentionally produced. _Levitation._--A raising of objects from the ground by supposed supernormal means; especially of living persons. _Medium._--A person through whom communication is deemed to be carried on between living men and spirits of the departed. It is often better replaced by _automatist_ or _sensitive_. _Message._--Used for any communication, not necessarily verbal, from one to another stratum of the automatist's personality, or from an external intelligence to the automatist's mind. _Metallæsthesia._--A form of sensibility alleged to exist which enables some hypnotised or hysterical subjects to discriminate between the contacts of various metals by sensations not derived from their ordinary properties of weight, etc. _Metastasis._--Change of the seat of a bodily function from one place (_e.g._, brain-centre) to another. _*Metetherial._--That which appears to lie after or beyond the ether: the metetherial environment denotes the spiritual or transcendental world in which the soul may be supposed to exist. _*Methectic._--Of communications between one stratum of a man's intelligence and another. _Mirror-writing_ (_écriture renversée, Spiegel-schrift_).--Writing so inverted, or, more exactly, _perverted_, as to resemble writing reflected in a mirror. _Mnemonic chain._--A continuous series of memories, especially when the continuity persists after an interruption. _Motor._--Used of an impulse to action not carrying with it any definite idea or sensory impression. _Negative hallucination_ or _systematised anæthesia_.--Signifies the condition of an entranced subject who, as the result of a suggestion, is unable to perceive some object or to hear some sound, etc. _Number forms._--See _Secondary sensations_. _Objectify._--To externalize a phantom as if it were a material object; to see it as a part of the waking world. _*Panmnesia._--A potential recollection of all impressions.