OSSEOUS FISHES. 
533 
times by one, sometimes by the other wand, though their extremities 
are close together. 
The experiments already related in connection with the torpedo were 
repeated here. If we place ourselves upon an isolated support, and 
take hold of a metallic rod, a shock is received; but no shock is 
received, on the other hand, if the fish is touched with a glass-rod, 
or one covered with wax. Humboldt and Bonpland repeated this 
experiment many times, with decisive results. The electric organ 
has been carefully described by these observers. The organs extend 
from under the tail, occupying nearly onc-half of the thickness. It 
is divided into four longitudinal bundles of muscles, the upper ones 
large, the two smaller below, and against the base of the anal fin. 
Each bundle consists of many parallel membranous plates, placed 
closely together and very nearly horizontal. These plates abut in one 
part on the skin, in another, on the mean vertical plane of the fish. 
They are united to each other by an infinity of smaller plates, placed 
either vertically or transversely. The smaller prismatic and trans- 
versal canal, intercepted by these two orders of plates, are filled with 
gelatinous matter. All this organic apparatus receives many nerves, 
and presents, in many respects, an arrangement nearly analogous to 
that of the torpedos. 
The Sea-Eels (Mur&na Helena) are serpent-like fishes, of cylin- 
drical form and delicate proportions, but strong, flexible, and active, 
swimming in waving, undulating movements in the water, just as 
a serpent creeps on dry land. The murmnas have no pectoral fin ; the 
dorsal and anal fin are reunited in the tail fin. A bronchial opening 
is observable on each side of the body. The sea-eels are numerous in 
species. Murasna Helena (Fig. 364), which is an inhabitant of the 
Mediterranean, has only a single row of teeth upon each jaw. It 
attains the length of forty to fifty inches. It loves to bask in the 
hollows of rocks, approaching the coast in spring-time. It feeds on 
crabs and small fishes, seeking eagerly for polypes. The voracity of 
these fishes is such that when other food fails they begin to nibble at 
each others tails. 
The sea-eels are caught with rod and line, or by lines and ground- 
hait, but their instinct is such that they often escape. When they 
have swallowed a hook they often cut the line with their teeth, or 
they turn upon it and try, by winding it round some object, to strain 
