The responses were as follows: Five said it did more violence to the series to have the alternate varied than the major unit; it was more confusing. Three preferred it, giving as their reason that it made the elements more different from each other than before, hence more easily distinguished. The preponderance of evidence was, therefore, that, although any variation from symmetry in a unit was likely to be detrimental to the repetition, it was more likely to be tolerable in the major unit than in the alternate space. In either case it was demanded that the two units be distinctly different, and it depended on the individual subject, whether in this experiment the variation of one unit or the other brought out this distinction more obviously. Aside from this consideration, however, it appeared that the alternate spaces as such required equilibrium more than the principal unit. Also, variation of symmetry in the major unit, while it made it more prominent in the way of _eccentricity_, also made the symmetrical minor unit more prominent in the way of _interest_. As one subject expressed it, "Since the others vary, the attention requires something which does _not_ vary, and forces prominence on the minor unit, because it remains symmetrical"; and "The minor unit is too small to merit such prominence as it gets by lack of symmetry. It is distorted, and has not enough content to bear it." These introspections from temporal and spatial subject alike, all point to the fact of a certain _value_ attached to the alternating units in a series. (1) The units must not be too much alike in _interest_, or they rival each other. (2) They must not have more prominence given them as regards the whole than they have interest to sustain. (3) There must be a congruity between the two elements so that one shall not be noticeable in one way, and one in another, thus carrying the attention in two different directions. One more thing was suggested by this experiment: (4) The subjects who had invariably _grouped_ their different elements in other series found it very difficult to do so in this, or wholly impossible. None of them did so when taking the series naturally, but moved on from one to the next just as the rhythmic type did. They felt "forced to move on," "no place to rest," while one in whom the rhythmic feeling was weakest was much fatigued by this movement, and insisted on having something stable to rest upon if he was to gain any pleasure at all. Next the series was varied by making both units unsymmetrical; first with the balance tipping the same, and second in opposite ways.