A similar work was Maeterlinck's, written in 1909 for a German review, and then transformed into a long and interesting chapter of the well-known volume, "L'hote Inconnu" (10).

Then in 1914 was published a book by E. G. Sanford (5) containing some useful comparisons between "thinking" animals and mediumistic psychology.

In Italy there were indications in the same sense, in the work of Stefani (1913), Professor Siciliani (1914), and others. But the subject was but little followed up.

Even psychologists by profession seemed for a time to be willing to accept the hypothesis of some "telepathic" transmission of thought from the investigators to the Elberfeld horses.

Already Claparede (1912) had been forced to refer to this, although he refused, so to speak, to discuss the matter; then G. C. Ferrari, and F. Pulle, in an interesting account (4) relate how the horse taken by them for instruction sometimes guessed the numbers that they were proposing to them, and rapped out the answers before being asked to do so.

Whatever may be the fate of the telepathic hypothesis, it may not be amiss to remind the reader that it undoubtedly is very closely connected with the mediumistic. The distinction between them is not always easy; besides, both may exist together side by side.

"Telepathy," so called, (a term not less unfortunate than that of "medium" and its derivatives), or, better, the transmission of thought, is (shortly put) the hypothesis that at a certain moment an agent transmits, and a receiver perceives, some definite mental image or state of mind. The transmission may be more or less willed (i.e. conscious) on the part of the agent; on the part of the receiver, however, the fact of the transmission always remains unconscious, but the psychical elements perceived bring about a reaction in consciousness and the receiver knows what he is doing, or at any rate may do so, at the moment of the occurrence. Shortly stated, it may be regarded as a kind of suggestion, "à distance," with sometimes immediate and sometimes delayed effect; a kind of posthypnotic performances of a suggestion without the intervention of hypnotism (or, perhaps, with a partial subhypnotic state?), the receiver of the suggestion not receiving it in the form of acoustic vibrations or in any way by means of one of the ordinary senses.

Mediumistic phenomena on the other hand require for their explanation the possibility of a much more direct, more profound and more immediate relationship between the several minds taking part in them. One of these minds—more or less disassociated—might become the instrument of another—even of several others—although still itself in a state of more or less complete disassociation, and always remaining altogether unconscious of its relationship to the other. One of the minds might therefore be an agent, another a recipient, or even several of them simultaneously might join together to produce the phenomena, the subliminal nature of the relationship remaining fixed. The actors would in this way, for ever, all of them without exception, be absolutely unaware that they were the actors. It might also be the case that the recipient through whom the phenomena are produced (i.e. the "medium," or in our case the animal experimented on) would not be conscious at all of the resulting action. With human "mediums" we should find in such cases a more or less advanced state of trance or ecstasy. And with regard to animals, I remember the opinions of Ochorowicz and others—which were preceded, however, long ago by a similar opinion of Cuvier—according to which the consciousness of animals in an awakened state would correspond fairly closely to the consciousness of man in a hypnotic state.

If what has been said above is at all correct, it would seem as if the walls separating various minds one from another all of a sudden are opened wide, and by a partial interpenetration of one mind by the other the several minds join together to produce by mutual determination automatic action. And it is in these special psychical states that "supernormal" phenomena, viz., psychography, clairvoyance, clairaudience, etc., occur.

Now, although all this is to move in a very uncertain ambit, harassed by a multitude of diverse and vain dilettantisms and mysticisms, and only too frequently by fraud, it is not any longer possible nowadays to deny that facts, objectively known, compel the positive scientist to have recourse to some such suppositions. Also without making the "subliminal," with Myers, a kind of "deus ex machina" in the world, it is certain that mediumistic phenomena of the kind mentioned are henceforth to be considered as a subject of study for an open-minded psychology. I may refer in support of this view, among others, to the powerful work of Morselli. And to return to the "thinking" animals, we find that the mediumistic hypothesis, however shifty it may seem, is a better explanation than the telepathic hypothesis—which has already itself become rather more systematized in modern psychology.