STRUCTURE OF ELECTRIC APPARATUS. 343 
Fishes which possess them, no definite information can be 
given. It is doubtful to what extent they are employed in 
obtaining food ; since it is known that the Gymnotus eats 
very few of the fishes which it kills by its discharge ; and 
that Torpedos kept 
in captivity do not 
seem disposed to ex- 
ercise their powers 
on small fishes placed 
in the water with 
them. The chief use 
of their electrical 
power appears to be, 
to serve as a means 
of defence against 
_ their enemies. 
422. The electric 
organs of the Torpedo 
(fig. 178) are of flat- 
tened shape, and 
_ occupy the front and 
‘sides of the body, 
“forming two large 
“Masses, which ex- 
tend backwards and 
outwards from each 
side of the head. 
They are composed 
of two layers of mem- 
brane, the space be- 
tween which is di- 
vided by vertical Fig. 178.—Execrric Apparatus oF ToRPEDO. 
partitions into hex- ¢, brain ; me, spinal cord; 0, eye and optic nerve; e, 
agonal ls, Tike Soames apa Se 
comb, the ends of which are directed towards the two sur- 
faces of the body. These cells—which are filled with a whitish 
soft pulp, somewhat resembling the substance of the brain, 
but containing more water—are again subdivided horizontally 
by little membranous partitions ; and all these partitions are 
profusely supplied with vessels and nerves.—The electrical 
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