48 ELECTRICAL GYMNOTE. 



ing or shortening his body, he can swim forwards or 

 backwards with apparently equal ease to himself, 

 which is another property of the vermicular tribe. 

 When he swims forwards, the undulations or wavy 

 motions of the fin and carina begin from the upper 

 part, and move downwards; but when he swims 

 backwards, and the tail goes foremost, the undula- 

 tions of the fin begin at the extremity of the tail or 

 fin, and proceed in succession from that backwards to 

 the upper part of the body : in either case he swims 

 equally swift. Every now and then the fish lays 

 himself on one side, as it were, to rest himself, and 

 then the four divisions of the body above mentioned 

 are very distinctly seen, viz. the vermiform appear- 

 ance of the two upper divisions ; the retiform ap- 

 pearance of the carina, and the last or dark-coloured 

 fin, whose rays seem to be exceedingly soft and 

 flexible, and entirely at the command of the strong 

 muscular carina. When he is taken out of the 

 water and laid on his belly, the carina and fin lie 

 on one side, in the same manner as the ventral 

 fin of the Tetraodon does, when he creeps on the 

 ground. I have been the longer and more parti- 

 cular in the description of the external structure of 

 this animal's body, because I think, as it is of a 

 most singular nature, and endowed with some amaz- 

 ing properties, even the most minute circumstance 

 I was able to observe relating to it should be men- 

 tioned. The power it has of giving an electrical 

 shock to any person, or to any number of persons 

 who join hands together, the extreme person on 

 each side touching the fish, is its most singular and 



