354 



pole and the leg is acted upon by an inverse derived current, and 

 that the thigh is traversed by a direct derived current. Thus 



Fig. 3. 



Hence there ought to be, as there is in fact, and as the Table 

 shows, contraction in the thigh when the current begins to pass, and 

 in the leg when the current ceases to pass. 



A. similar diagram and table will give the case in which a loop of 

 sciatic nerve is acted upon by the inverse primitive current, and show 

 at a glance that the leg ought to contract at the beginning of the 

 current, because the current, acting upon the portion of nerve nearest 



Fig. 4. 



