For further details, see Lecture VI, p. 169. Footnote 49: Prince: Mechanism and Interpretation of Dreams, _Jour. of Abn. Psych._, October-November, 1910. Footnote 50: If, lacking this knowledge of the data, any one chooses to insist that it was not the conserved residua of previous thoughts, but of the dream itself (the only alternative entertainable explanation) which induced, _after waking_, the hallucinatory phenomena and blindness, we still fall back upon the same principle, namely, that of the subconscious functioning of conserved residua of a conscious experience producing a physiological (and psychological) effect. Footnote 51: According to recent researches of Sidis in conjunction with Kalmus, and later with Nelson (The Nature and Causation of the Galvanic Phenomenon, Psychological Review, March, 1910) similar galvanic phenomena under similar conditions may be caused by the _generation_ of an electric current within the body. Footnote 52: The test word (e. g., boat, stone, hat, etc.) of course represents an idea which may have various associations in the mind of the subject. Footnote 53: Morton Prince and Frederick Peterson: Experiments in Psycho-Galvanic Reactions from Coconscious (Subconscious) Ideas in a Case of Multiple Personality, _Journal of Abnormal Psychology_, April-May, 1908. LECTURE V NEUROGRAMS We have got as far as showing that the phenomena of memory to be intelligible require that ideas which have passed out of mind must be conserved through some sort of residuum left by the original experience. But this as a theory of memory is incomplete; the question remains, _How_, and in what form, manner, or way, are they conserved? In other words, What is the nature of the residuum? Is it psychical or physical?[54] As we have seen, from the fact that something outside of the personal consciousness can manifest memory of a given experience at the very same moment when the personal consciousness has amnesia for that experience, we are compelled to infer that conservation must be by a medium, psychological or physiological, capable of being excited as a specific secondary process. Now this medium must be either an undifferentiated “Psyche” or specific differentiated residua. In the former case we postulate a concept of a transcendental something beyond experience and of which, like the soul after death, we have and can have no knowledge. To this concept of an undifferentiated Psyche we shall return presently.