are as
follows:

The horse failed in his responses whenever the solution of the problem
that was given him was unknown to any of those present. For instance,
when a written number or the objects to be counted were placed before
the horse, but were invisible to everyone else, and especially to the
questioner, he failed to respond properly. Therefore he can neither
count, nor read, nor solve problems in arithmetic.

The horse failed again whenever he was prevented by means of
sufficiently large blinders from seeing the persons, and especially the
questioner, to whom the solution was known. He therefore required some
sort of visual aid.

These aids need not, however,--and this is the peculiarly interesting
feature in the case,--be given intentionally. The proof for this is
found in the fact that in the absence of Mr. von Osten the horse gave
correct replies to a large number of persons; and to be more specific,
Mr. Schillings and later Mr. Pfungst, after working with the horse for
a short time, regularly received correct answers, without their being in
any way conscious of having given any kind of signal.

So far as I can see, the following explanation is the only one that will
comport with these facts. The horse must have learned, in the course of
the long period of problem-solving, to attend ever more closely, while
tapping, to the slight changes in bodily posture with which the master
unconsciously accompanied the steps in his own thought-processes, and to
use these as closing signals. The motive for this direction and
straining of attention was the regular reward in the form of carrots and
bread, which attended it. This unexpected kind of independent activity
and the certainty and precision of the perception of minimal movements
thus attained, are astounding in the highest degree.

The movements which call forth the horse's reaction, are so extremely
slight in the case of Mr. von Osten, that it is easily comprehensible
how it was possible that they should escape the notice even of practised
observers. Mr. Pfungst, however, whose previous laboratory experience
had made him keen in the perception of visual stimuli of slightest
duration and extent, succeeded in recognizing in Mr. von Osten the
different kinds of movements which were the basis of the various
accomplishments of the horse. Furthermore, he succeeded in controlling
his own movements, (of which he had hitherto been unconscious), in the
presence of the ho