FESSARD: ACTIVITY OF ELECTRIC PLATES 509 



(Cole and Hodgkin^^). Furthermore, electrometric determinations on 

 isolated portions freed from the internal derivations normally present 

 in the intact animal, should reveal much higher resting potentials. This 

 was never observed. 



c. It appears to us that the following question should be resolved 

 first: Do polarized layers really exist in the plate, previous to its state 

 of activity? To prove this, it is necessary to communicate in some 

 way with the interior of the plates. 



1. We have tried piercing slowly a column from the electric organ 

 of Torpedo with a fine metallic electrode and have observed small re- 

 petitive discharges, due to a mechanical excitation, which we have shown 

 to be caused by irritation of the nerve twigs encountered.^ When the 

 electrode is extremely fine, a number of plates may be perforated 

 without being excited and without giving rise to those systematic vari- 

 ations in potential we might expect when passing through one plate to 

 the following. 



2. We also took small groups of columns, one of which we slit lat- 

 erally with the edge of a heated blade. The measurements were started 

 immediately with the ordinary method of opposition, one electrode be- 

 ing placed on the killed region, the other as far as possible from it, on 

 the intact tissue of the same column. The resting potential had to be 

 dissociated from the long-lasting residuals of activity, following the 

 excitation produced by the lesion (cf. Gotch^-). Three methods were 

 tried: first, allowing the residuals to vanish; second, diminishing their 

 disturbing effect by a transverse arrangement of the electrodes; third, 

 using a degenerated preparation. 



The results in these 3 cases are exemplified in figure 1. In figure 

 1 (2), the A electrode, being a little more dorsal than B, is positive 

 at the start, according to the direction of the discharges. However, it 

 rapidly reverts to its steady potential value, which is negative, rela- 

 tively, to B. In (3), no initial discharge is present as expected. 



In all cases, no value higher than 5 mv. has been obtained for this 

 rest potential. This is 20 to 30 times less than the elementary dis- 

 charge. We cannot believe that such a discrepancy can be completely 

 due to a shunt effect. 



The preceding results, incomplete as they are, throw a serious doubt 

 on the value of the first and second hypotheses. The alleged perma- 

 nent polarization may not, therefore, exist, at least not at sufficient 

 strength to play the more important part in the discharge. This sug- 

 gests a third hypothesis that we formulated once,* and according to 



