The next step in the analysis of the complication experiment, bringing it into relation with the simple coördination of two disparate stimuli, is to show, if possible, the influence of the _series_ of _visual_ impressions. This naturally divides into two lines, namely, (1) the _length_ of the series as such, and (2) the relative influence, in case of a given kind of displacement, of the part of the series coming _after_ the auditory stimulus, and the part _preceding_ it. For the first, I used in comparison, a series of twelve letters, a series of three, and a single letter. For the second, the letter, whose coördination with the click was set as the task of the observer, was made successively the first, the last, and the middle member of a series of five letters. During each hour of experimentation, the observer was tested as to his accuracy of localization of the click, (1) in a series of twelve letters at intervals of .083 sec., (2) in a series of three at the same interval, and (3) with reference to a single letter. The method for the first two was exactly as in the preceding experiments. In the case of the single letter, he was asked to localize as accurately as possible in terms of the intervals as he remembered them from the series. This introduced an element of uncertainty. One observer, St, would not give any judgments as to time-differences in the case of the single letter. Another method had to be adopted in order to obtain more comparable results. These results (Table III) are presented as showing, by comparison with the following table, the transition from one method to the other. Clicks were at 2-sec. intervals. Each number in the table is the average result of fifty or more experiments. They are in thousandths of seconds, and the plus and minus signs indicate positive and negative displacements. TABLE III _Observer_ _Twelve Letters_ _Three Letters_ _One Letter._ A +.012 sec. -.029 sec. -.010 sec. G -.022 sec. +.004 sec. -.004 sec. Sh +.028 sec. -.079 sec. -.057 sec. St -.050 sec. -.036 sec. Bo +.029 sec. -.015 sec. -.022 sec.