construct concepts which are allegories, metaphors, symbolisms, personifications of concrete phenomena. Their use tends to fallacious reasoning and to perverted inductions from the facts. Becoming major premises in a syllogism, they lead to erroneous interpretations of the simplest facts, just as fixed ideas or obsessions tend to a perverted interpretation of the environment. We are now in a position to see that the psycho-physiological theory of memory has a far-reaching significance. The facts which have been brought before you in evidence of the theory have been selected largely from those which were capable of verification by experimentation and by other objective testimony. They include a large variety of experiences which occurred in pathological conditions like amnesia and multiple personality, and in artificial conditions like hypnosis and intoxication. Such abnormal conditions enable us to show by testimony, independent of the individual, that these experiences had actually occurred, and, therefore, to show that the reproductions of these experiences were in principle truthful memories. They also enable us to appreciate the enormous variety and quantity of experiences which, although absolutely beyond the power of voluntary recall, may be conserved nevertheless as neurograms, and also to appreciate the minuteness of detail in which the brain records may be preserved. If you will stop a moment to think, and give play to your imagination, you will see that the principle of the neurographic conservation of experiences must be true not only of our outer life, of our experiences with our environment, but of our whole _inner life_, normal as well as abnormal. It is always possible that any thought, any feeling, however trivial and transitory, may leave neurograms in the brain. It is always possible that even a fleeting doubt or scruple, thoughts which flash into the mind and straightway are put out again, all may leave their records and dispositions to function again. Even a passing doubt which any of you may entertain regarding the interpretation of the phenomena I have described, and the correctness of our conclusions, may be recorded. Indeed, it is a matter of some importance for the understanding of abnormal mental conditions that many of those horrid little sneaking thoughts which we do not like to admit to ourselves, the thoughts which for one reason or another we endeavor to repress, to put out of our minds, may leave their indelible traces. In fact, these are the very thoughts, the ones which we try hardest to forget, to push aside, which are most likely to be conserved. The harder we try, the stronger the feelings attached to them, the more likely they are to leave neurograms in the brain though they may never be reproduced. This has been shown by observation of pathological conditions, like hysteria and psychasthenia, and by experimentation. In repressing our thoughts we do not put them