I offer no excuse for multiplying these observations of hallucinatory phenomena, even at the expense of tedious repetition, for such studies give an insight into the mechanism of the hallucinations met with in the insanities and other pathological states. They offer, too, an insight into the basic process involved in dreams as these are a type of hallucinatory phenomena. It is by a study of hallucinations experimentally created, and others where we are in a position to know the causal factors, that we can learn the mechanisms underlying similar phenomena occurring in normal pathological conditions. As a rule in the latter conditions it is difficult to determine beyond question the true causal factors and, therefore, the particular subconscious processes involved. Such phenomena as I have presented justify the conclusion of the “new psychology” that the _hallucinations of the insane_ are not haphazard affairs but the resultant of subconscious processes evoked by antecedent experiences. In conclusion, then, we may say that _in artificial hallucinations as experimentally conducted, and in certain spontaneous hallucinations, we have two known factors; the causal factor (the antecedent experience) and the hallucinatory phenomenon—the effect. Intervening between the two is an inferred subconscious process of considerable complexity which is required to explain the causal connection_. With the exact mechanism of hallucinatory phenomena we are not at present concerned, but only with the evidence of the actuality of a subconscious process, of its character as an intelligence, and with its intrinsic nature. As to the last problem it is plain that further investigations are required and that the methods at present at our disposal for its solution leave much to be desired. All things considered a conservative summing up would be that the subconscious process may be both coconscious and unconscious.