fact that the scope of apperception is a relatively limited and constant one, and that the scope of apprehension is not only larger, but also much more variable. And, as we have clearly seen from our comparison of simple and complex rhythmical rows, it varies according to the scope of the psychical complexes that are united together into one whole. Thereby the difference between the merely apprehended and the apperceived parts of such a whole by no means disappears. For it is only a limited part of this latter that lies within the focus of attention, as has been strikingly shown in reading experiments, where we can vary single and merely apprehended parts of a word, without thereby disturbing the comprehension of the total complex. To use a picture which is itself an example of this phenomenon, we may say that that wider darkly apprehended content stands in the same relation here as the chords of the piano accompaniment to the voice of the singer. Slight variations in the former are mostly unobserved, so long as the guiding voice is correct in pitch and rhythm. On the other hand, the impression of the whole would be feeble if the accompaniment was wanting. In this relationship between the apprehended and apperceived content of consciousness another factor appears, which brings to light the great importance of the processes of apperception. We started out from the fact that it was extremely difficult to apprehend with absolute uniformity a row of identical beats, since we are always inclined to accentuate certain beats. This phenomenon is clearly connected with a fundamental characteristic of apperception, which intervenes in all processes of consciousness. We know, from ordinary life, that we are not able to direct our attention perfectly steadily and uniformly to one and the same object. When we attempt to do this, we notice that a continual change takes place in the apperception of the object in question. At times the attention turns towards the object most intensively, and at times its energy flags. Where the conditions remain uniform, this change gradually becomes regular and periodic. The rise of such a process is of course materially assisted, if the outside impressions themselves, to which our attention is directed, possess a regular periodicity. This is the case in a high degree with a row of beats. And so it happens that those oscillations of apperception are directly adjusted to the periodicity of the impressions. Therefore we emphasise an impression that coincides with a rise in the apperception wave, so that the beats which are in fact uniform become rhythmically arranged. The manner of this arrangement depends to a certain degree upon our own choice, and also upon the extent in which we are trying to combine the single impressions into a whole. If the beats follow each other very quickly, our endeavour to combine leads us easily into complicated rhythmical arrangements, as we have in fact noticed above.