LIVING TORPEDOS IN BERLIN. 



and relatively negative but absolutely positive when they were 

 heterodromous. After long-continued tetanus of the gymnotus 

 organ Sachs found that the tetanus current was weakened rather 

 than strengthened, as is the case after a single shock (see above, 

 p. 445). But this does not explain the result of my experiment. 

 Unfortunately up to the present I have only been able to make 

 it a few times, with an organ in impaired state of functional 

 activity, so that I cannot altogether trust its result. 



There is still one method of experiment at hand which under 

 certain conditions might lead to the attainment of the object, that 

 is to observe whether with a longer closing time the homodromous 

 current maintains its ascendancy. If this is the case, positive 

 polarisation cannot be identified with the shock, for the latter, 

 when a constant current goes for a long time through the organ, 

 can only add itself to the battery current at the moment of closing. 

 I have in fact seen this ascendancy with a closing time of i", 5", 

 or even 20" (Series 8, 15, 16, 25) but experiments of this kind 

 will not be conclusive until the hypothesis of an irreciprocal re- 

 sistance is completely set aside. 



It is obvious that nothing remains but to set oneself patiently 

 to further investigations, the road to which is, however, clearly 

 indicated. The next consignment of Torpedos will bring us a step 

 nearer to the determination of the present question. 



14. On the electromotive Actions of the Electrical Nerves 

 of the Torpedo. 



The only researches as to the electromotive actions of electrical 

 nerves which had hitherto appeared were those which I had made 

 on the Malapterurus. The nerve showed no current between the 

 longitudinal and transverse section when at rest, and no negative 

 variation in tetanus ; but with two Groves it gave weak but 

 undoubted indications of electrotonus currents 1 . Its functional 

 activity was already considerably diminished ; it would not, how- 

 ever, be surprising if even the perfectly fresh nerve gave neither 

 rest current nor negative deflection, for the transverse section of 

 the single fibre which runs in the axis of the nerve, bears to the 

 total transverse section a relation varying from I : 90 to I : IO4 2 . 

 In consequence of this extraordinary peculiarity in the construction 

 of the electrical nerve of Malapterurus, the result is just as if no 



1 Gesammelte Abhandlungen, ii. p. 645. 



3 Ibid., ii. p. 645. N.B. A misprint here puts 8950 for 89.50. 



