192 STUDIES IN ELECTRO-PHYSIOLOGY: 



CHAPTER XIV 

 THE NODES OF RANVIER 



IN these the axis -cylinder is invariably shown as passing 

 in an uninterrupted course through the node, but although 

 it is highly speculative and daring to say so, I doubt 

 whether this is the case functionally, although we must 

 believe it to be so anatomically. The following illustration 

 is a typical one : 



Fig. 102. MEDULLATED NERVE-FIBRE SHOWING FIBRILS or Axis 

 CYLINDER (BETHE). The fibrils are seen passing, without interruption, 

 across a node of Ranvier. (After G. N. Stewart.) 



Now, these nodes occur at regular and innumerable 

 intervals along the course of an axis-cylinder, but their 

 function appears, so far as my reading goes, to be im- 

 perfectly understood. If, unlike their prototypes in the 

 bamboo and the sugar-cane, the axis-cylinder is struc- 

 turally continuous throughout its course, they do not seem 

 to serve any useful purpose. If, on the other hand, there is 

 a species of synapse at each node, their purpose and function 



