58 ELECTRICAL GYMNOTE. 



are equal to the breadths of the septa between 

 which they are situated. There is a regular series 

 of them continued from one end of any two septa 

 to the other. They appear to be so close as even 

 to touch. In an inch in. length there are about two 

 hundred and forty, which multiplies the surface of 

 the whole to a vast extent. 



" The nerves in this animal may be divided into 

 two kinds : the first appropriated to the general pur- 

 poses of life ; the second for the management of this 

 peculiar function, and very probably for its exist- 

 ence. They arise in general from the brain and 

 medulla spinalis, as in other fish ; but those from the 

 medulla are much larger than in fish of equal size ; 

 and larger than is necessary for the common opera- 

 tions of life. The nerve which arises from the brain, 

 and passes down the whole length of the animal 

 (which I believe exists in all fish), is larger in this 

 than in others of the same size, and passes nearer 

 to the spine. In the common eel it runs in the 

 muscles of the back, about midway between the 

 skin and spine. In the cod it passes immedi- 

 ately under the skin. From its being larger in this 

 fish than in others of the same size, one might 

 suspect that it was intended for supplying the organ 

 in some degree ; but this seems not to be the case, 

 as I was not able to trace any nerves going from it 

 to join those of the medulla spinalis, which run to 

 the organ. This nerve is as singular an appearance 

 as any in this class of animals ; for surely it must 

 appear extraordinary, that a nerve should arise from 

 the brain to be lost in common parts, while there is 



