Physiological "Polarity" and Electrical Polarity. 347 



not appear to have, any relation to the kind of regeneration that 

 takes place. 



(8) That when, on the other hand, the cut surface is allowed 

 to heal, and when later a new structure has begun to appear, the 

 differences in potential between the new and the old parts {as 

 measured on the surface only) are not such as can be made to ac- 

 count for the difference in the kind of part (head or tail) that is 

 regenerating. Here also many complications enter into the re- 

 sult and make it difficult to draw satisfactory conclusions. 



(9) No definite relation was found between the rate of growth 

 and the fall of potential between an uninjured surface and a cut 

 end. 



