102 



ANIMAL ELECTRICITV. LECTURK V 



The nerve Is facino- you ; and the connections are 

 such that the direction in which the spot moves 

 represents the direction of current through the 

 nerve. Closing- the key, I make a polarising- cur-, 

 rent In the direction p p' ; there Is a considerable 

 deflection to your right, indicating the presence of 

 an extrapolar current in the nerve in the same direc- 

 tion from e to e', or towards the polarised region of 



EiG. 44. — Diagram of experiment to demonstrate A. and K. 



the nerve. This Is an Anelectrotonic current, so- 

 called because it Is on the Anodic side of p p'. 



Turning over the reverser to the left, and again 

 closing the key, I make the polarising current In the 

 opposite direction p' p ; there is now a rather less 

 pronounced deflection to your left, that indicates the 

 presence of an extrapolar current in the nerve to your 



