THE SYMPATHETIC SYSTEM 263 



system, cerebro spinal axis, and nerves. A vegetative 

 life system, system of ganglia. 



We must show: That these systems have their centres 

 superimposed, in the nervous axis except for a few excep- 

 tions and are themselves controlled by higher centres 

 which are to be found in the anterior portion of the brain 

 in the neighborhood of the higher psychic centres; that 

 the nerves coming from the vegetative axis centres have 

 for particularity to be interrupted, in ganglia outside 

 these centres; finally that the nerves of the vegetative life 

 are throughout the organism, distributed in a series of tissues 

 which have to do with the upkeep of the individual and the 

 species. These are the main facts. Let us now see, how 

 these systems are planned and how they function. 



IL THE ANATOMICAL VEGETATIVE NERVOUS UNITY. 



Before going into the description of these systems, we 

 must analyze the various parts and describe successively, 

 the vegetative nerve cell, the vegetative neuron and the 

 vegetative arc. 



THE VEGETATIVE NERVE CELL AND THE 

 VEGETATIVE NEURONS. 



Do vegetative nerve cells distinguish themselves from 

 the neurons of animal life? Certainly, for one thing the 

 central and ganglionic vegetative cells are slightly different 

 from the nerve cells of animal life and furthermore, the 

 axis cylinder of these cells have an entirely different aspect. 



I don't want to enter here into a histological description 

 of the comparative characters of these two types of 

 neurons; all that I will say is that the vegetative fibres are 

 of two kinds: 



AMYELINIC Fibres without a myelin coat of Remak, or 

 gray fibres and vegetative with myelin fibers whose chief 



