DREAMS AND ILLUSIONS. 253 



hemispheres. Owing to the excitement caused by 

 wakefulness, by fatigue, by sunshine, or in some cases 

 by the condition of the nerves of the stomach, the 

 objective projection on psychical space, partly trans- 

 mitted by heredity and gradually formed by associa- 

 tions and local signs,* is arrested by the innate force 

 of the image on the organ, and it appears to be 

 smaller and in proportion with the relative sniallness 

 of the image which is produced by minute vibrations 

 and by the susceptibility of the cellule. This inter- 

 mediate and persistent stage of hypnagogic images 

 serves in every way to explain the physical genesis of 

 involuntary hallucinations. 



As a proof that the image physiologically assumes 

 the form of a real appearance, I may mention the 

 experience of myself and others. When suddenly 

 awakened from a vivid dream I have sometimes, even 

 when I was fully awake, seen for an instant the 

 figures of rny dream still moving, and projected on 

 the wall. This fact shows that even the images of 

 our waking state have, in the physiological conditions 

 of the brain, a tendency to take real forms, so that 

 they may be termed normal, or more properly, 

 inchoate hallucinations, corrected by the conscious 

 efforts of our waking state and external conscious- 

 ness. So that it might be said that dreams are at 

 first the transformation of our waking thoughts into 



* See the theory by Lotze of local signs in the formation of the 

 idea of space, completed and modified by Wundt and others. 



