SIZE OE THE GTMNOTtTS. 
116 
they have lost.* The mules and horses appear less fright- 
ened; their manes are no longer bristled, and their eves 
express less dread. The gymnoti approach timidly the edge 
of the marsh, where they are taken by means of small 
harpoons fastened to long cords. When the cords are very 
dry the Indians feel no shock in raising the fish into the 
air. In a few minutes we had five large eels, most of which 
were but slightly wounded. Some others were taken, by 
the same means, towards evening. 
The teniDerature of the waters in which the gymnoti 
habitually five, is from 26° to 27°. Their electric force 
diminishes it is said, in colder waters ; and it is remarkable 
that, in general, animals endowed with electromotive organs, 
the effects of which are sensible to man, are not found in 
the air, but in a fluid that is a conductor of electricity. The 
gymnotus is the largest of electrical fishes. I measured 
some that were from five 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, with- 
out reckoning the anal fin, which is elongated in the form 
of a keel, was three inches and a half. The gymnoti of the 
Cano de Bera are of a fine olive-green. The under part of 
the head is yellow mingled with red. Two rows ot small 
yellow spots are placed symmetrically along the back, from 
the head to the end of the tail. Every spot contains an 
excretory aperture. In consequence, the skm 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 in general somewhat remark- 
able, that no electric fish yet discovered in the different 
parts of the world, is covered with scales.t 
* The Indians assumed us that when the horses are made to run two 
days successively into the same pool, none are killed the secoud duv. 
See, on the fishing for gymnoti, “ Views of Nature.” (Bohn’s ed., p. IS.) 
f We yet know with certainty only seven electric fishes ; Torpedo 
narkc, Risso, T. unimaculata, T. marmorata, T. gaivjnii, Silurus elec- 
tricus, Tetraodon electriens, Gymnotus electricus. It appears uncertain 
whether the Trichiurus indicus has electrical properties or not. (S«® 
Cuvier’s Regne Animal, vol. ii.) But the genus Torpedo, very different 
from that of the rays properly so called, has numerous species in the 
equatorial seas; and it is probable that there exist several gymnoti 
