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58 Adaptations of Fishes 
mead that leprosy may be so carried. It is further suggested 
that the custom of eating the flesh of fishes raw almost uni- 
versal in Japan, Hawaii, and other regions may be responsible 
for the spread of certain contagious diseases, in which the fish 
acts as an intermediate host, much as certain mosquitoes spread 
the germs of malaria and yellow fever. 
Electric Fishes.—Several species of fishes possess the power 
to inflict electric shocks not unlike those of the Leyden jar. 
This is useful in stunning their prey and especially in confound- 
ing their enemies. In most cases these electric organs are 
evidently developed from muscular substance. Their action, 
which is largely voluntary, is in its nature like muscular action. 
The power is soon exhausted and must be restored by rest and 
food. The effects of artificial stimulation and of poisons are 
parallel with the effect of similar agents on muscles. 
In the electric rays or torpedos (Narcobatide) the electric 
organs are large honeycomb-like structures, ‘‘ vertical hexag- 
lic. 42.—Electrie Catfish, Torpedo electricus (Gmelin). Congo River. 
(After Boulenger.) 
onal prisms,’’ upwards of 400 of them, at the base of the pec- 
toral fins. Each prism is filled ‘‘ with a clear trembling jelly-like 
substance.’’ These fishes give a shock which is communicable 
through a metallic conductor, as an iron spear or the handle of 
a knife. It produces a peculiar and disagreeable sensation not 
at all dangerous. It is said that this living battery shows all 
the known qualities of magnetism, rendering the needle mag- 
netic, decomposing chemical compounds, etc. In the Nile is 
an electric catfish (Torpedo electricus) having similar powers. 
Its electric organ extends over the whole body, being thickest 
below. It consists of rhomboidal cells of a firm gelatinous 
substance. 
The electric eel (Electrophorus electricus), the most powerful 
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