48 THE POPULAR SCIENCE MONTHLY 
mally heightened in dreams. Every impression reaches sleeping con- 
sciousness through this emotional atmosphere, in an enlarged form, 
vaguer it may be, but more massive. The sleeping brain is thus not 
dealing with actual impressions—if we are justified in speaking of the 
impressions of waking life as “ actual ”—even when actual impressions 
are being made upon it, but with transformed impressions. The prob- 
lem before it is to find an adequate cause, not for the actual impression 
but for the transformed and enlarged impression. Under these cir- 
cumstances symbolism is quite inevitable. Even when the nature of 
an excitation is rightly perceived its quality can not be rightly perceived. 
The dreamer may be able to perceive that he is being bitten but the 
massive and profound impression of a bite which reaches his dreaming 
consciousness would not be adequately accounted for by the supposition 
of the real mosquito that is the cause of it; the only adequate explana- 
tion of the transformed impression received is to be found (as in a 
dream of my own) in a creature as large as a lobster. This creature is 
the symbol of the real mosquito. We have the same phenomenon 
under somewhat similar conditions in the intoxication of chloroform 
and nitrous oxide. 
The obscuration during sleep of the external sensory channels and 
the checks on false conclusions they furnish is not alone sufficient to 
explain the symbolism of dreams. The dissociation of thought during 
sleep, with the diminished attention and apperception involved, is also 
a factor. The magnification of special isolated sensory impressions in 
dreaming consciousness is associated with a general bluntness, even an 
absolute quiescence, of the external sensory mechanism. One part of 
the organism, and it seems usually a visceral part, is thus apt to mag- 
nify its place in consciousness at the expense of the rest. As Vaschide 
and Piéron say, during sleep “the internal sensations develop at the 
expense of the peripheral sensations.” That is indeed the secret of the 
immense emotional turmoil of our dreams. Yet it is very rare for 
these internal sensations to reach the sleeping brain as what they are. 
They become conscious not as literal messages, but as symbolical trans- 
formations. The excited or laboring heart recalls to the brain no mem- 
ory of itself but some symbolical image of excitement or labor. There 
The magnification we experience in dreams is manifested in their emo- 
tional aspects and in the emotional transformation of actual sensory stimuli, 
from without or from within the organism. The size of objects recalled by 
dreaming memory usually remains unchanged, and if changed it seems to be 
more usually diminished. “ Lilliputian hallucinations,” as they are termed by 
Leroy, who has studied them (Revue de Psychiatrie, 1909, No. 8), in which 
diminutive, and frequently colored, people are observed, may occasionally occur 
in alcoholic and chloral intoxication, in circular insanity and in various other 
morbid mental conditions. They are usually agreeable in character, and con- 
stitute a micropsia which is supposed to be due to some disturbance in the 
eortex of the brain. 
