it seemed as if all the conditions necessary for the
formation of number-concepts were supplied. However, the most essential
thing had to be presupposed, viz.: that the horse virtually possessed
the general power of forming concepts,[AK] and that all that had been
lacking was the suitable conditions for its development. Mr. von Osten
held tenaciously to this conviction, and it was this conviction that was
the basis for the infinite patience with which the tests had been
pursued.

[Footnote AJ: The author intends to take up the problem of counting,
so-called, on the part of animals and of the principle involved, in
another work soon to be forthcoming.]

[Footnote AK: There are some who believe they are warranted in
concluding the opposite from the structure of the animal's brain
alone. We may say that the brain of the horse, compared with that of
the ape, or even that of the dog, represents a relatively low type
of development. But owing to the rapid changes in the views, often
contradictory, concerning the nature of the nervous structures and
processes underlying the thought process, any conclusion based on
such views would be premature. For this reason we cannot agree with
the French physiologist who was dissecting the brain of a horse and,
struck by its smallness of size, exclaimed: "When I saw your proud
look and beautiful neck, I hesitated a moment before mounting upon
your back. But now that I have seen how small is your brain, I no
longer have any qualm about using you."[98]]

To come now to the learning process itself;--we may assume that, at
first, whenever the horse began to tap in response to commands, he would
receive a reward for this purely mechanical feat. Wooden pins were then
planted on the ground and designated as: one, one two, etc., and each
time someone would raise the horse's foot as many times as the count
demanded (see Supplement I). Then Mr. von Osten would take his stand at
the horse's side and would command him, let us say, to tap 3. Hans
noting merely (from his master's position) that he was expected to tap,
would begin. The instructor, who had bent forward in order to watch the
horse tapping,[AL] would involuntarily straighten up again at the third
tap, without being conscious of it and quite unaware that he was thus
giving a signal. The horse would be startled, and sometimes he would
immediately cease tapping and sometimes not