1907] Some Curious Facts About Fishes 231 



Electric Fishes. 



There are three kinds of fishes, unrelated to each other, which 

 possess electric functions : that is, they are capable of giving 

 electric shocks. They are the Torpedoes, or Electric Rays ; the 

 Electric Eel ; and the Sheath-fishes, or Electric Cat-fishes. There 

 are others, the names of which need not be mentioned, which 

 possess elementary or pseudo-electric organs. The electric mus- 

 cular substance is differently adjusted in the three kinds enumer- 

 ated. In the Torpedoes the batteries lie on either side of the head; 

 in the Electric Eel they are longitudinal bodies in two pairs, im- 

 mediately below the skin ; and in the Sheath-fishes they extend 

 all over the body, being thickest on the abdomen. 



I had once an opportunity to test the powers to give electric 

 shocks which two of these three kinds of fishes possess. Being 

 invited by the keeper of the aquarium of the Zoological Gardens 

 in London to receive a shock from an Electric Eel, I placed my 

 hands upon the fish and received it, but it was slight, a circum- 

 stance probably due to the fact that the eel was not at home in its 

 changed environment. Shortly afterwards Dr. Forbes, who kindly 

 escorted me through the aquarium of the Liverpool Public Museum 

 asked if I would like a shock from an electric cat-fish. I 

 remembered the slight shock which the eel had given, and there- 

 fore readily placed my hands on the side of the fish, but the shock 

 it gave was so violent that I would not again care to repeat the 

 experiment. 



Fishes which Take Care of their Progeny. 



The vast majority of fishes, of which there are some 13,000 

 known species, take no care whatsoever oi their progeny. The 

 eggs are deposited, and then immediately fecundated, and the 

 parents never see their young, unless they should afterwards 

 encounter them, as they might other fishes, and perhaps devour 

 them. A comparatively few, however, do take care of their young. 

 In some such as the black bass and certain cat-fishes both parents 

 do. In a few only the female does. The females of the cat-fishes 

 of the genus Aspredo, of Guyana, press the eggs into a spongy 



