"The theory that I will next examine seems to me decidedly more plausible, from its analogy to the conclusion to which I am brought by the examination of the evidence for phantasms of the living. This theory is that the apparition has no real relation to the external world, but is a hallucination caused in some way by some communication, without the intervention of the senses, between the disembodied spirit and the percipient, its form depending on the mind either of the spirit or of the percipient, or of both. In the case of haunted houses, however, a difficulty meets us that we do not encounter, or at least rarely encounter, in applying a similar hypothesis to explain phantasms of the living, or phantasms of the dead other than fixed local ghosts. In these cases we have generally to suppose a simple _rapport_ between mind and mind, but in a haunted house we have a _rapport_ complicated by its apparent dependence on locality. It seems necessary to make the improbable assumption, that the spirit is interested in an entirely special way in a particular house (though possibly this interest may be of a subconscious kind), and that his interest in it puts him into connection with another mind, occupied with it in the way that that of a living person actually there must consciously or unconsciously be, while he does not get into similar communication with the same, or with other persons elsewhere. "If, notwithstanding these difficulties, it be true that haunting is due in any way to the agency of deceased persons, and conveys a definite idea of them to the percipients through the resemblance to them of the apparition, then, by patiently continuing our investigations, we may expect, sooner or later, to obtain a sufficient amount of evidence to connect clearly the commencement of hauntings with the death of particular persons, and to establish clearly the likeness of the apparition to those persons. The fact that almost everybody is now photographed ought to be of material assistance in obtaining evidence of this latter kind.