PATHOLOGY OF SENSIBILITY 35 



peripheral autonomic systems have also a finely organised 

 posterior horn. Hence I believe it is not correct, at the 

 present stage of science, to speak of a higher form of sensi- 

 bility which is conducted in the posterior columns and of a 

 lower form which is conducted in the anterior part of the 

 lateral columns. 



In my opinion the chief difi'erence between these two forms 

 of sensory pathways is the following. The so-called vital 

 sensibility is closely connected with autonomic functions, 

 and, as I mentioned already, much of it is brought to the 

 central nervous system by non-medullated fibres. At all 

 events it is associated in the gray substance with sym- 

 pathetic centres and there causes, amongst other things, 

 reflex movements in the sympathetic area. This form of 

 sensibility causes feelings, which are of significance for the 

 emotional life. 



The other form of sensibility proceeds through the pos- 

 terior columns and avoids the gray substance. It sends 

 collaterals to this part of the spinal cord, but does not ter- 

 minate there. The impulses, conducted in the direction of 

 the cortex, do not originate in the autonomic nervous sys- 

 tem and are not associated with it. They should be called 

 non-autonomic. 



Hence we reach the following conception about the 

 organisation of sensibility in the central nervous system. 

 The sensory stimuli are spread through the spinal cord and 

 the brain in two separate systems. The first is the non- 

 autonomic system. It is composed of long tracts, of simple 

 build and enters the cortex of the brain in a circumscribed 

 area. This organisation bears the stamp of an exact 

 localization. In this system impulses are conducted for 

 gnostic sensory functions, which at a high level of the brain 

 may cause sensory observations but no sensory feelings. 



The second is the vital system, closely connected with the 

 autonomic system. It is composed of some long and of 

 many small tracts, very complex in build, and enters the 



