[Footnote S: In a special series of experiments a subject was instructed to execute rapid head movements as minute and as evenly as possible. These were registered objectively and at the same time I made judgments concerning them. The results showed that my judgments were most exact in the case of the most minute jerks. The thing that made it especially easy to judge the movements of Mr. von Osten under normal conditions, (page 220), was their extraordinary evenness, such as I have not met with in any other individual.] Let us now turn to a discussion of the several figures. Figure 6 (von Allesch) gives a typical view of the great, and at the same time economic concentration of attention characteristic of the subject. Respiration (first curve) is not so profound as usual, yet is changed very little. The head-jerk (fourth curve) is of medium height. It occurs just at the proper moment,--the subject had thought of 2, and had directed his attention economically. This attention was of the kind described as type I on page 93. The lowering of the head, (recorded in the figure by a rise in the curve), immediately following upon the head-jerk upward, is irrelevant. In figure 7 (Chaym) we have a record of a different nature. Respiration was inhibited throughout the test,--(the small waves are due to the pulsating of the heart); immediately after the test deep breathing takes place. Tension steadily increased till 3, the number expected, was reached. The head, accordingly, gradually sank a little forward. The head-jerk ensued during an interval beginning just before the reaching of the goal and ended immediately after. The movement was predominantly backward, its upward direction being only through a distance of 1/4 millimeter. (This subject was not so strongly motor as the preceding one.) The reaction followed promptly as seen in curve 6. It was the decided raising of the head which follows the head-jerk, that prevented the usual back-step with the left foot, when the subject was working with Hans. [Illustration: FIG. 6.] [Illustration: FIG. 7.] Figure 8 (von Manteuffel) is typical of strong and at the same time economical concentration. Respiration, normally deep and very regular, is for a time completely inhibited. Tension rises steadily and the head gradually inclines forward. In the interval between the number before the final one and the final one the subject makes a sudden bend forward and immediately upon reaching the final number gives a violent jerk of the head, upward. The attention here would be characterized as being of type III, described on page 94. (Owing to lack of space it is impossible to give an example of type II, which is only to be found in the case of very large numbers.)