but this is rather unusually polite. More often it would be a telepathized apparition of Elsie herself, perhaps with an added auditory hallucination "I am dying," or "Good-by," or with a sad expression, or with dripping clothes, if the death were by drowning. If it were not possible to manage this as an externalized hallucination, it might appear as an extraordinarily vivid dream.
In the many cases where bits of the circumstances are shown (such as a part of the ship or building where the accident or whatever happened), circumstances which the percipient could not have known, it must be supposed that the two producers have pooled their information through the intercommunicating subconscious.
We are still, however, dealing only with what goes on in one person's mind. There are cases of several normal, fully awake people having the same hallucination. Mr. Tyrrell deals with this significant "collective percipience of apparitions," of which a number of attested cases exist.
They may be telepathic "infection" from one to the other percipient, but in some of the cases quoted by Mr. Tyrrell where several people have seen the same "apparition," they have seen it as it would have looked from their different points of viewing it if it had been "real"; that is, the person in back of the apparition sees its back, the one at the side sees the side, etc., though it also happens that one or two of the persons present either see nothing at all or else get only a confused perception. Or, if the apparition "speaks," they may hear and not see it, or vice versa.
Mr. Tyrrell's theory, backed by much evidence, is that the "producer" levels of the different personalities, who are necessary for the "reality" of the apparition, are all acted upon by the agent and perhaps by the chief percipient. According to the capacity of each, all the producer levels then get to work and produce in each the view of the apparition which that person in fact would have seen if something physically "real" had been there. (Incidentally, Mr. Tyrrell asks, how, if the various aspects of the same apparition seen simultaneously by several people are caused by physical traces in the brain, do the brain traces in the various brains get into a state of exact correlation with each other?)
The cases collected by the English Society over a long period of time (more than sixty years) and from many different localities, so
