202 STUDIES IN ELECTRO-PHYSIOLOGY: 



be, taken up by the storage-ganglia to replace the charge 

 given out by them, the process of recovery, as shown by 

 the string galvanometer, is slow. The hypothesis, there- 

 fore, that the ganglion cells receive " charge " and not 

 '' irritations " seems to be tenable. In Thornton's Human 

 Physiology we are told that by a nerve-centre we must 

 understand a ganglion cell, or group of cells, capable of 

 receiving, modifying, and discharging nerve impulses, and 

 thus acting for the performance of some function. As I 

 have explained it, this is intelligible. Reject that explana- 

 tion and no one law remains to account for all the 

 phenomena. There can only be one law, and that law 

 applies with equal force to both the animal and vegetable 

 worlds. Every observed phenomenon must be in harmony 

 with it, if the observer is not in error. 



Turning again to Thornton, the following passage is 

 worth quoting : " Experimental excitation shows that the 

 anterior root " (of a spinal nerve) " contains efferent fibres 

 and the posterior afferent fibres. . . . Other fibres pass 

 by these cells and do not appear to be connected with 

 them. What their nature is cannot yet be stated." All 

 this is consistent with condenser-action, and may be 

 explained by it. What appears to be required is that the 

 specialist physiologist should collaborate with the specialist 

 electrician in the study of the human nervous system, and 

 I think this will have to be done if appreciable progress is 

 to be made during our lifetime. 



" Upon the object of autonomic ganglia I can find nothing 

 which conflicts with the views I hold. ..." Nature has, 

 as it were, before her the problem of supplying with nerves 

 the vast mass of muscles in the body, and the space at her 

 command in the various exits from the cranium and spinal 

 canal does not allow of more than a comparatively small 

 outflow from the central nervous system. 



"The difficulty is met to some extent by the branching 



