Bozzano at that time was necessarily ignorant of the "thinking" animals, for it was only afterwards that they came to notice. But there were other authors who introduced the possibility (or the necessity) of a supernormal relationship in order to explain the Elberfeld facts, as soon as they were known. Perhaps the first in chronological order was De Vesme, who published in 1912 an interesting article in that sense (3), showing the many analogies between the phenomena of Elberfeld and mediumistic phenomena generally, e.g. the typtological particularities; the wrong orthography ("Firaz" tapped by the horse to express its own name "Zariff," "Dref" instead of "Ferd," etc.); solutions of difficult problems and invincible resistance to simple inquiries; immediate promptitude of correct replies to complicated mathematical problems, etc. 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.