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 "&* l^S. ELECTRIC APPARATUS OF TORPEDO. 



partitions into hex- c, brain; me, spinal cord; o, eye and optic nerve; e, 

 afOTial fplls ^ lilrp electric organs ; tip, pneumogastric nerve, supplying 



us, e, like electric or * gans '. f ateral n - Jn d ** 



those of a honey- 

 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 



