CATCHING THE GYMNOTUS. 365 



" The temperature of the water in which the gymnoti ha- 

 bitually live is about 86 degrees of Fahrenheit. Their electric 

 force, it is said, diminishes in colder waters. The gymnotus 

 is the largest of electrical fishes. I measured some that were 

 from four feet to five feet three inches long ; and the Indians 

 assert, that they have seen them still larger. We found that a 

 fish of three feet ten inches long weighed twelve pounds. The 

 transverse diameter of the body was three inches five lines. 

 The gymnoti of Cano de Sera are of a fine olive-green colour. 

 The under part of the head is yellow, mingled with red. Two 

 rows of small yellow spots are placed symmetrically along the 

 back, from the head to the end of the tail. Every spot con- 

 tains an excretory aperture. In consequence the skin of the 

 animal is constantly covered with a mucous matter, which, as 

 Volta has proved, conducts electricity twenty or thirty times 

 better than pure water. It is somewhat remarkable, that no 

 electrical fish yet discovered in the different parts of the world, 

 is covered with scales. 



' ' It would be rashness to expose ourselves to the first shocks 

 of a very large and strongly irritated gymnotus. If by chance 

 you receive a stroke before the fish is wounded, or wearied by 

 a long pursuit, the pain and numbness are so violent, that it 

 is impossible to describe the nature of the feeling they excite. 

 I do not remember having ever received from the discharge of 

 a large Leyden jar, a more dreadful shock than that which I 

 experienced by imprudently placing both my feet on a gym- 

 notus just taken out of the water." 



The Torpedo. It would be difficult to name two fish more 

 dissimilar in outward appearance than the Gymnotus and the 

 Torpedo, and yet they enjoy in common the unique power of 

 communicating electric shocks. The Gymnotus is a long eel- 

 like fish, the Torpedo is round and flat. The Torpedo be- 

 longs to the family of the Rays, and sometimes reaches a large 

 size. It is common in the Mediterranean and is sometimes 

 found on the southern coasts of the British Isles. 



