by something not in the content of consciousness,—something we have called a secondary process, of which the individual is unaware. We can conceive of the phenomenon originating in either one of two possible modes. Either the hallucination was a newly fabricated conscious experience; or it was a reproduction of secondary visual images originally belonging to the auditory perception at the time of its occurrence and now thrust into consciousness in an intensely vivid form. In either case, for this to have taken place something must have been left by the original experience and conserved apart from and independent of the content of the personal consciousness at any and all moments—something capable of functioning after an interval of time as a secondary process _outside of the personal consciousness_. The only intelligible explanation of the phenomenon is that the original auditory impression persisted, somehow and somewhere, in a form capable of conservation as a specific and independent residuum during all subsequent changes in the content of consciousness. This residuum either fabricated the hallucination or thrust its secondary images into consciousness to become the hallucination. The phenomenon by itself does not permit a conclusion as to the nature of the residuum, whether it is psychological or neural; i.e., whether an auditory perception, as perception, still persists subconsciously outside the focus of awareness of consciousness, or whether it has left an alteration of some kind in the neurons. Whatever the inner nature of the conserved experience it _obviously must have a very specific and independent existence, somehow and somewhere, outside of the awareness of consciousness, and one capable of secondary functioning in a way that can reproduce the original experience in terms of another sense. In other words, conservation must be in the form of some kind of residuum, psychological or neural_. It must be, therefore, something very different from reproduction or a recurrent phase of consciousness. Further, it must form a stage in the process of memory of which reproduction is the final result.