DliEAMS. 271 



Dreams, due to more or less perfect brain activity, are 

 often traceable to nerve impulses brought from the digestive^ 

 tract, from the respiratory organs, from the skin (heat and 

 cold and pressure), from any internal organ, according to the 

 condition of the blood, pressure, sound, etc. It seems to be 

 well settled that dreams seeming to cover long periods of 

 time are really gone through with in a very short space of 

 time, just as sometimes during waking hours thoughts fly 

 through the mind in countless numbers and with incredible 

 swiftness. 



Do we have dreams when we recall none ? Without 

 attempting to answer this question, it is well to note that the 

 brain undoubtedly is constantly receiving nerve currents to 

 which it pays no heed, or at least of which we are not con- 

 scious. For instance, our clothing is touching nearly the 

 whole of the surface of our bodies, and, plainly, the surfaces 

 thus touched are affected. Undoubtedly currents go to the 

 brain ; but, as they are of no significance in ordinary circum- 

 stances, we learn to disregard them. If a savage were sud- 

 denly clothed as fully as we are, he would, for a long time, 

 be continually conscious of the fact. 



We ordinarily disregard many forces that are operating 

 upon us ; many sounds are ignored, many objects we do not 

 see as they really appear to us. For instance, if one sits 

 behind a bald-headed man in a church, in looking over the 

 top of his head at the choir, the top of his head appears 

 peaked, because while the eyes are focused on the more dis- 

 tant object, the images of the man's head, as seen by the two 

 eyes, do not coincide, but overlap each other ; and what is 

 seen is the part where the two images overlap, which forms 

 a pointed arch. We may be sure this is what we always see, 

 but seldom notice. And this is only a sample of the many ap- 

 pearances and sensations that we have learned to ignore. To 



