ELECTRICAL GYMNOTE. 



59 



a medulla spinalis giving nerves to the same parts. 

 It must still remain one of the inexplicable circum- 

 stances of the nervous system. The organ is supplied 

 with nerves from the medulla spinalis, from which 

 they come out in pairs between all the vertebrae of 

 the spine. In their passage from the spine they give 

 nerves to the muscles of the back, &c. They bend 

 forwards and outwards upon the spine, between it 

 and the muscles, and send out small nerves to the 

 external surface, which join the skin near to the 

 lateral lines. These ramify upon the skin, but are 

 principally bent forwards between it and the organ, 

 into which they send small branches as they pass 

 along. They seem to be lost in these two parts. 

 The trunks get upon the air-bladder, or rather dip 

 between it and the muscles of the back, and con- 

 tinuing their course forwards upon that bag, they 

 dip in between it and the organ, where they divide 

 into smaller branches: they then get upon the 

 middle partition, on which they continue to divide 

 into still smaller branches ; after which they pass on, 

 and get upon the small bones and muscles, which 

 are the bases for the under fin, and at last they are 

 lost on that fin. After having got between the or- 

 gan and the above-mentioned parts, they are con- 

 stantly sending small nerves into the organs ; first 

 into the great organ, and then into the small one; 

 also into the muscles of the fin, and at last into the 

 fin itself. These branches, which are sent into the 

 organ, as the trunk passes along, are so small that I 

 could not trace their ramifications in the organs. In 

 this fish as well as in the Torpedo, the nerves which 



