ANIMAL AND VEGETABLE 195 



node above the cut, together with the unipolar cells and 

 receiving instrument, would be in working order, and only 

 that portion of skin in connection with the lower part of 

 the nerve thrown out of gear. If, however, there were no 

 line of resistance at the node above the cut, all the circuits 

 with which the nerve is functionally associated would 

 suffer, the nerve and the cells lose their charge, and the 

 receiving instrument would be left idle. 



It is inconceivable, to my mind, that the resistance of 

 the axis-cylinder is not greater, much greater, at the nodes 

 than in the internodes, but as a matter of possibility this, 

 instead of involving a change of material, may be created 

 by constriction of the axon, as the effect of constriction in 

 the course of a liquid conductor is to materially lower 

 conduction at that point. 



In some works the nodes are called " constrictions," 

 and the suggestion is made that instead of the constriction 

 being due to a tightening of the sarcolemma it is effected 

 by a band (band of Ranvier) which compresses the axon. 

 How this may be I do not know, but I am convinced that 

 in whatever manner it is brought about there is con- 

 denser-action or similar cause of delay at every node. 



