ater became
resigned to it as an irremediable evil. Mr. von Osten was also aware
that the questioner ought not move while the horse was approaching a
colored cloth, and cautioned me in regard to it, though I had already
noted as much. And finally, he also knew what influence his calls had
while the horse was selecting the cloth, and he told me that it was of
great assistance to Hans to be admonished frequently, since thus his
attention was brought to bear upon the proper cloth. Yet, when we
requested Mr. von Osten to desist calling, since he was thereby
influencing the horse in the choice of the cloth, he answered: "Why
that's just what I wish to do!"--But though the statement that he was
aware of the nature of these grosser signs is thus seen to be true, it
by no means necessarily implies that he had purposely trained the animal
to respond to them. In these observations of his he had builded better
than he knew--he evidently had no notion of their scientific
significance. But the same thing might happen to those who were supposed
to be somewhat less naive, as is shown by the experience of Mr.
Schillings, who quite unconsciously, for many months had been giving not
only the finer, but also the grosser signs, and never guessed the true
nature of affairs until I explained it to him. Nor was it an easy matter
for me to get at the facts involved in the process, although it now all
appears so very simple.

On the other hand, it is also true that Mr. von Osten knew nothing
whatever of the finer, more minute signals, such as the final jerk, the
head-movement upward, downward, etc., and it is difficult to conceive
how he might have gained any knowledge of them. We might perhaps
conceive of four possible sources. He might have come upon them by
chance. But it is extremely improbable that in the million of possible
forms of signaling he should have hit upon those that at the same time
represent the natural expressive movements. Or he might have derived a
knowledge of them through a study of the pertinent literature. I have
searched diligently for such a source, in both the old and the modern
literature, but in vain. From the sixteenth century on, there is a
series of accounts of horses that were able to spell and to solve
problems in arithmetic, and the reports on learned dogs go back even to
the time of Justinian, in the middle of the sixth century.[107] All of
these animals were kept for purpose of speculation and were exhibite