which the horse began to react properly, the instructor's tenseness and excitement tended to decrease, and with this decrease of the emotional element in the man's consciousness, the accompanying non-voluntary, expressive movement gradually became less pronounced until it attained that extraordinary refinement which it possesses to-day. We noticed also, that whenever the horse, for any reason, had to be trained anew, Mr. von Osten's movements would, on the whole, become somewhat more gross, as for instance after the tests with the blinders. There is not a shadow of a doubt that this increase in the movement's extent was entirely unintentional, since the horse could not see his master at all on account of the blinders which had been attached to the trappings. [Footnote AL: This natural and close connection between the process of attention and the movement toward the object attended to is clearly expressed in our English and French terms, derived from the Latin "tendere ad--," to reach toward--.] In the same way it is possible to explain the details. Mr. von Osten himself said that at first Hans had tapped at times with his left foot, at times with his right, just as he pleased. But later his master taught him to tap only with the right. Whenever he began with the left, Mr. von Osten would immediately interrupt him, and he was allowed to add only a final tap with his left foot. Thus, this additional tap which was sometimes made with the left foot was but the vestige of an earlier rudimentary habit. The signal for it was the stooping posture in which the master remained after the head-jerk had been made. Whenever Mr. von Osten had given Hans a small number to tap, he would bend forward only a little. But when he expected a larger number he would bend forward somewhat more, owing to the desire to observe the tapping more carefully. From the slight inclination of the master's body the horse would get the cue that he was expected to tap for a short time only, by the greater degree of inclination he would know that he was to tap for a longer period. In the second case he tapped rapidly and did not raise his foot as high from the ground--evincing a regard for the saving of energy, which may well be attributed to a horse. And thus arose the connection between the degree of inclination of the instructor's body and the horse's rate of tapping.