confronted by the difficulty of proving that this increase of stimulation is objective, which is possible only in a small number of cases. If the dream of flying is a symbolisation of the upward and downward motion of the pulmonary lobes, either this dream, as has already been remarked by Strümpell, would be dreamt much oftener, or an accentuation of the function of breathing during the dream would have to be demonstrable. Still another case is possible—the most probable of all—that now and then special motives directing attention to the visceral sensations which are universally present are active, but this case takes us beyond the range of Scherner's theory.
The value of Scherner's and Volkelt's discussions lies in the fact that they call attention to a number of characteristics of the dream content which are in need of explanation, and which seem to promise new knowledge. It is quite true that symbolisations of organs of the body and of their functions are contained in dreams, that water in a dream often signifies a desire to urinate, that the male genital may often be represented by a staff standing erect or by a pillar, &c. In dreams which show a very animated field of vision and brilliant colours, in contrast to the dimness of other dreams, the interpretation may hardly be dismissed that they are "dreams of visual stimulation," any more than it may be disputed that there is a contribution of illusory formations in dreams which contain noise and confusion of voices. A dream like that of Scherner, of two rows of fair handsome boys standing opposite to each other on a bridge, attacking each other and then taking their places again, until finally the dreamer himself sits down on the bridge and pulls a long tooth out of his jaw; or a similar one of Volkelt's, in which two rows of drawers play a part, and which again ends in the extraction of a tooth; dream formations of this sort, which are related in great numbers by the authors, prevent our discarding Scherner's theory as an idle fabrication without seeking to find its kernel of truth. We are now confronted by the task of giving the supposed symbolisation of the dental stimulus an explanation of a different kind.
Throughout our consideration of the theory of the somatic sources of dreams, I have refrained from urging the argument
