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 spe. 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 thetr termination in the 
organ itself. 
In the electrical organ of the Silurus electricus, according 
to Grorrroy, 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 1s provided, pro- 
ceed from the eighth pair ; but are not so large im 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 
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