PECULIAR SECRETIONS. 371 



drangular pyramid, the height of which is equal to the 

 breadth of the organ, the apex centrad, and the narrow 

 sides dorsad and sternad. These partitions are so close to one 

 another, as even to appear to touch, making the cells ex- 

 ceedingly narrow. In an inch in length, there are about 

 240 partitions. These electrical organs have no peculiar 

 covering, being attached directly to the surrounding parts 

 by cellular substance. The two organs on the side, are 

 separated from each other by a thick membranous partition, 

 reaching from the skin to the centre. The organs are li- 

 berally supplied by bloodvessels. The nerves are nume- 

 rous, and arise from the medulla spinalis coming from it 

 in pairs, between all the vertebrae of the spine. Previous 

 to reaching the organ, they give out filaments to the mus- 

 cles of the back, and afterwards to the skin and air-bag. 

 Dr HUNTER was unable to trace their termination in the 

 organ itself. 



In the electrical organ of the Silurus electricus, according 

 to GEOFFROY, the structure is more simple than in the 

 Torpedo or Gymnotus. It consists of a bed of filaments 

 which cross each other in every direction, and form meshes 

 of very small dimensions. The whole is covered by a li- 

 gamentous membrane, which is itself covered with a layer 

 of fat. The nerves with which the organ is provided, pro- 

 ceed from the eighth pair ; but are not so large in propor- 

 tion as in the torpedo. 



When the hand is applied to the peculiar organs of an 

 electrical fish, the animal is observed to twist its body, as if 

 about to make a vigorous muscular exertion ; and a be- 

 numbing sensation is instantly felt in the fingers, and even 

 as far as the elbows. This sensation, however, is not al- 

 ways felt, as the animal appears to excite it only when ir- 

 ritated, or otherwise disturbed. It is capable of making 



A a 2 



