ANIMAL AND VEGETABLE 208 



of the out-flowing nerve-fibres, and in the case of the 

 voluntary muscles this appears to be sufficient. The 

 most striking example of this can be seen in the electrical 

 organ of the malapterurus, where the millions of its sub- 

 divisions on each side of the body are all supplied by the 

 branches of a single axis-cylinder process originating from 

 a single giant nerve-cell in the brain. 



" But in the case of the involuntary muscular tissue 

 there is an additional means of distribution, for each fibre 

 that leaves the central nervous system arborises around a 

 number of cells in the autonomic ganglia, and thus the 

 impulse is transferred to a large number of new axis- 

 cylinder processes. . . . The afferent or sensory fibres are 

 much less numerous than those which are efferent. . . . 

 Thus in the splanchnic and hypogastric nerves about one- 

 tenth of the fibres are found to be sensory, and in the 

 pelvic nerve about one-third of the total fibres are sen- 

 sory." (Halliburton, 1915.) 



UNIPOLAR AND BIPOLAR NERVE CELLS. 



Unipolar cells, as I have stated, are, in my view, storage 

 cells, and appear to be prominently associated with the 

 closed circuits of the sensory nerves. In common with 

 other nerve-cells they contain at least one conducting 

 substance in organically combined iron (Macallum), and 

 non-conducting substances, possibly the deep and super- 

 ficial relicula described by Golgi and regarded by J. Turner 

 as investments derived from neuroglia cells. However 

 that may be, I am constrained to the opinion that in all 

 nerve-cells we have a form or forms of condenser or Leyden 

 jar ; that is to say, they may consist of one or more jars, and 

 that, if more than one, these elements may be connected in 

 series or in parallel, for the regulation, adjustment, and 

 distribution of tension. 



