BIOELECTRIC rilENO.MENA 317 



but the problem of the precise nature of the transforma- 

 tion still presents many difficulties. 



The special development of bioelectric currents as a 

 means of attack and defense in the electric fishes is a 

 fortunate circumstance for general physiology, since the 

 structural conditions found in the electric organs are full 

 of suggestion for the general theory of the bioelectric 

 processes. These conditions indicate clearly, lirst, that 

 the powerful effects produced by these organs depend on 

 the summation of the potentials of numerous cellular 

 elements or ''disks" (apparently modified muscle cells) 

 arranged in series; and, second, that the action of each 

 single element depends on the alteration of a special and 

 definitely oriented portion of its protoplasmic surface 

 layer. This area is structurally characterized by the rich 

 branching of the nerve-terminals in contact with it; 

 it forms one face of each element, posteriorly directed 

 in the case of the electric eel, while the opposite or 

 anterior face is free from nerve fibers.^ One face of each 

 element is thus innervated and apparently undergoes 

 alteration or activation during activity, in a manner 

 which may be compared with that of an activated gland 

 cell, while the opposite face presumably remains un- 

 changed. The innervated and non-innervated surface 

 layers of adjacent elements thus alternate in position in 

 a manner comparable with the alternation of positive 

 and negative metallic plates in a battery of galvanic ele- 

 ments in series. A closer comparison would be with the 

 original galvanic ''pile," where each pair of plates, copper 



» Cf. Gotch's article in Schafer's textbook, II, 561, for an account 

 of the essential structure of the electric organ; also Bicdcrmann's 



Electro physiology and Bernstein's Elcklrobiologic. 



