We can obtain a further result from the experiment with the metronome described above, if we change the length of the ascending or descending row of beats. In our diagram each row, A and B, contains sixteen separate beats, or, taking one rise and fall together, eight double beats. If we listen attentively to a row of beats of this length when the metronome is going at a medium rapidity of, say, 1 to 1 1/2 seconds, and then after a short pause repeat a row of exactly the same length, we recognise immediately the identity of the two. In the same way a difference will be immediately noticed, if the second row is only by one beat longer or shorter than the first. It is immaterial whether we beat in ascending or descending rhythm. Now it is obvious that such an immediate recognition of the identity of two successive rows is only possible if each of them is in consciousness as a whole. It is not at all necessary for both of them to be in consciousness at the same time. We can see at once that consciousness must grasp them as wholes, if we consider for one moment an analogous case, e.g. the recognition of a complex visual image. If we look, for example, at a regular hexagon for a short time, and then cast another glance at the same figure, we recognise at once that both images are identical. Such a recognition is impossible if we divide the figure up into several parts and show these parts separately. Just as the two visual images appeared in consciousness as wholes, so must each of our rows of beats appear as a whole, if the second is to call up a similar impression to the first. The difference consists in this, that the hexagon was perceived in all its parts at once, whereas the beats followed each other in succession. Just because they follow in this way, such a row of beats possesses this advantage, that we can thereby determine precisely how far we can extend such a row so that it is still possible to grasp it in consciousness as a whole. It has been proved by such experiments that sixteen successive beats, alternately rising and falling, or so-called 2/8 time, is the maximum for such a row, in order that all the separate elements may still find room in our consciousness. We may therefore consider such a row as a measure for the scope of consciousness under these given conditions. At the same time it appears that this measure is, between certain limits, independent of the rapidity of succession of the beats. A grasping together of the row as a whole becomes, however, impossible, when the beats follow each other so slowly that no rhythm may be heard, or when the rapidity is so great that the 2/8 time is lost, and the mind tries to group the beats together in a more complicated rhythm. The former limit lies at about 2 1/2 seconds, and the latter at 1 second.