ELECTRIC SHOCKS BY ANIMALS 181 



and smooth skin. Inhabiting the rivers and lakes 

 of Brazil and the Guianas, and called by the Spanish 

 settlers by the name of ' Tremblador,' the creature 

 sometimes attains to a length of eight feet, and 

 may have a girth equal to that of a man's thigh ; 

 while, moreover, its powers of discharging an electric 

 shock are far greater than those of any other fish 

 thus endowed. The electric organs are situated 

 in the tail, and are composed of numerous cells 

 containing a jelly-like substance. 



The fish are very abundant in certain districts 

 of their habitat, and the natives capture a large 

 number of them for food by a method which, 

 according to Mr. Holder, is called * embarbascar con 

 caballos,' or ' intoxicating by means of horses.' 

 Humboldt, who originally described the proceeding, 

 states that mules and horses are driven into the 

 water wherein the eels are lurking, whereupon the 

 fish proceed to show their displeasure at being 

 disturbed, and possibly trodden on, by discharging 

 their electrical current into the bodies of the unfor- 

 tunate quadrupeds. The latter are forced to 

 remain in the water until the eels have temporarily 

 exhausted their powers by continually delivering 

 electric shocks, when the natives then leap upon 

 the backs of their steeds and proceed to spear 

 and land the fish whilst their means of offence and 

 defence lies dormant. Occasionally, however, a 

 man may happen to alight upon an individual 

 which has not depleted its reserve of current, with 

 the result that he receives a shock, conducted 

 through the wet cord attached to the spear-head, 



