_Obs._ _One Visual and_ _One Pair_ _Many Auditory_ _Many Pairs_ A Threshold Mean After Letter (sec.) .005 After Letter .022 After Letter .042 Range (sec.) .021 .024 .039 G Threshold Mean After Letter (sec.) .022 After Letter .009 After Letter .005 Range (sec.) .078 .083 .084 H Threshold Mean Before Letter (sec.) .011 After Letter .006 After Letter .012 Range (sec.) .035 .035 .039 Hy Threshold Mean After Letter (sec.) .034 After Letter .030 After Letter .046 Range (sec.) .089 .074 .072 St Threshold Mean After Letter (sec.) .054 After Letter .037 After Letter .041 Range (sec.) .096 .080 .083 In this experiment, the observers A, H, and Hy, show an increasing distance of the threshold mean after the visual stimulus, with the successive introductions of the auditory series and the combined series. In other words, the second column negative displacement is larger than that of the first, and the third column has a still larger. G and St are again exceptions, as they would be expected to be from the above analysis of their methods. Each did his most accurate work in a case where there was some rhythm present. St said in regard to this work "the one pair abolishes the sound as a standard." The rhythmic factor most missed by these observers, in the case of the single pair, was the sound; for their results are almost the same in the second and third columns. Introduction of the repetition of the visual series does not make any decided difference. A, H, and Hy were able so to adjust their attention as to get the best results in the case of the single pair. The rhythm seemed to introduce for them a subjective rhythm which upset the nice adjustment of attention and so increased the displacement or the time between the threshold mean and the visual stimulus. The negative displacement was increased under these circumstances, probably as a result of the facilitation of the auditory perceptive process. It has an _opened path_. It is a case of pre-perception. Even when both were repeated (many pairs) the auditory dominated, and so did the most at opening its path. But it seems more likely to me that the rhythm, as such, whether auditory or auditory and visual, claimed the attention and so proved a distraction from the work of accurately discriminating the times of the impressions. And this exaggerated the displacement or lack of discrimination in whichever direction it was tending before.