482 
VERTEBRATA. 
the Few York markets : hnt its flesh is nnsavory. It is a vicious animal, snapping at any thing 
near it, wlien captured. 
Genus MURiENA : Murcena, in- 
cludes tlie MuRJiiNA, M. Helena, a 
celebrated species, common in all 
parts of the Mediterranean, and oc- 
casionally met with on the coasts 
of Great Britain. It is four to six 
feet long, and lives in fresh or salt 
water ; its flesh is white, and of good 
flavor. It was greatly esteemed by 
the ancient Romans, who kept large 
supplies of it in their numerous vi- 
varia. Julius Caesar, in one of his 
triumphs, distributed six thousand of these fishes among his friends. 
THE GYMNOTID^. 
Genus GYMNOTUS : Gymnotus, includes the Electrical Eel, G. electricus, Avhich fi-equents 
the ponds and marshy places of South America. This fish possesses a most Avonderful power 
of commimicating an electrical shock to any thing with which it comes in contact ; and this is 
said to he sufficiently strong to knock down a man, and deprive him of the use of a limb for 
some hours. It attains a length of five or six feet, and as the apparatus from which the elec- 
tricity is evolved extends throughout the greater part of its body, it may readily be imagined 
that the discharge of such a battery must be formidable. The apparatus is composed of four 
longitudinal bundles, placed one on each side of the dorsal, and one on each side of the ventral 
region of the body. These bundles are composed of a multitude of horizontal parallel plates, 
which are intersected by transverse vertical plates, the quadrangular canals thus formed being 
filled with a gelatinous matter. The whole apparatus is liberally supplied with nerves, and may 
be considered to represent an exceedingly complicated galvanic battery. So powerful, in fact, is 
the current of electricity evolved by it, that it can decompose chemical compounds, and magnet- 
ize steel needles. It appears that the anterior portion of the apparatus is positive, and the pos- 
terior negative; and that those parts of it only which are in contact with an object are. impli- 
cated in the production of the current. Nevertheless, it is said that the animal can make use 
of it in bennmbing small fishes at some distance from it in the water. The Indians of South 
America, when they wish to capture this fish, commence their operations by driving a number 
of horses and mules into the ponds inhabited by them ; the eels, alarmed at the disturbance, im- 
mediately attack the intruders upon their quiet domain, usually applying their entire length to 
the bellies of the unfortunate quadrupeds, and thus gi\'ing the full eftect of the whole electrical 
apparatus. Some of the horses soon become disabled, and falling down in the water, are 
drowned ; the others, being driven back by the shouts and whips of the Indians, continue the 
conflict until the powers of the gymnoti are, for the time, exhausted. These then endeavor, in 
their turn, to escape from the scene of warfare, and for this purpose approach the shore, where 
another enemy awaits them : the Indians, anned with harpoons attached to long cords, strike at 
all that come within reach, and by jerking them rapidly out of water, so as to keep the cord 
from getting wet, contrive to secure their booty without receiving any shock. 
Several other species of this family are found in the waters of South America, but none of them 
appear to possess electrical properties. Mr. Wallace found ten species in the small streams near 
the sources of the Rio Negro and Orinoco : he says that they are all eaten, but that, owing to the 
number of forked bones which they contain, they are but little esteemed. The Indians informed 
him that a rostrated species, common in the rivers, has a very singular and ingenious manner of 
obtaining its nourishment. They state that its principal food consists of ants and white ants, 
insects which are exceedingly abundant in those regions, and that, to procure them, it approaches 
the shore and lays its tail upon the ground. The ants, attracted by the slimy matter with which 
THK MURiBNA. 
