than corresponding visual sensations. Yet the rushing,
roaring sound caused by the circulation of the blood in the ear is,
probably, a not uncommon starting-point in dreams. With respect to
subjective sensations of smell and taste, there is little to be said. On
the other hand, subjective sensations due to varying conditions in the
skin are a very frequent exciting cause of dreams. Variations in the
state of tension of the skin, brought about by alteration of position,
changes in the character of the circulation, the irradiation of heat to
the skin or the loss of the same, chemical changes,--these are known to
give rise to a number of familiar sensations, including those of
tickling, itching, burning, creeping, and so on; and the effects of
these sensations are distinctly traceable in our dreams. For example,
the exposure of a part of the body through a loss of the bed-clothes is
a frequent excitant of distressing dreams. A cold foot suggests that the
sleeper is walking over snow or ice. On the other hand, if the cold foot
happens to touch a warm part of the body, the dream-fancy constructs
images of walking on burning lava, and so on.

These sensations of the skin naturally conduct us to the organic
sensations as a whole; that is to say, the feelings connected with the
varying condition of the bodily organs. These include the feelings which
arise in connection with the processes of digestion, respiration, and
circulation, and the condition of various organs according to their
state of nutrition, etc. During our waking life these organic feelings
coalesce for the most part, forming as the "vital sense" an obscure
background for our clear discriminative consciousness, and only come
forward into this region when very exceptional in character, as when
respiration or digestion is impeded, or when we make a special effort of
attention to single them out.[85] When we are asleep, however, and the
avenues of external perception are closed, they assume greater
prominence and distinctness. The centres, no longer called upon to react
on stimuli coming from without the organism, are free to react on
stimuli coming from its hidden recesses. So important a part, indeed, do
these organic feelings take in the dream-drama, that some writers are
disposed to regard them as the great, if not the exclusive, cause of
dreams. Thus, Schopenhauer held that the excitants of dreams are
impressions received from the internal regions of the organis