62 THE ZOOLOGIST. 
electric organs of fishes. Aristotle seemed to have pondered 
long the peculiar force by which the electric ray numbed the 
fishes that came within its reach, and Darwin after long and 
careful consideration, came to the conclusion, that the electric 
organs offered a special difficulty to his theory of natural 
selection. And although, as the result of numerous investi- 
gations, a considerable increase had recently been made to our 
knowledge of these organs, it was still impossible to account for 
their origin, in some cases to offer an opinion as to their 
function, or even to say whether they were progressive structures, 
or mere useless vestiges. The Torpedo and other electric fishes 
fascinated the Greeks, and to a less extent the Romans, and 
held their ground during the dark ages. One of the most 
noteworthy facts about electric organs was that they were only 
found among fishes, and that’ although there were hundreds 
of different kinds of fishes, there were practically only three 
kinds that were known to have electric batteries sufficiently 
powerful to be of any evident use. These were Malapterurus of 
the Nile and other African rivers, the Gymnotus of South 
America, and the Torpedo found at times in our own waters, 
and in considerable numbers in the Mediterranean and the 
Atlantic. Others, in which electric organs were known to 
exist, were the once sacred Oxyrhynchus of the Nile, and the 
Skates and Rays which abound round the coast of Scotland. 
The Malapterurus was a quaint-looking fish, with a fatty dorsal 
fin like the Salmon, and six long barbules around the snout. It 
was said sometimes to reach a length of four feet. In this fish 
the electric battery was in the form of a continous subcutaneous 
jacket or tunic, which invested the whole body, with the 
exception of the head and fins. It consisted of a countless 
number of minute cells, from which electricity was thrown off at 
will. The Gymnotus was a soft-skinned, sluggish creature, with 
small stupid-looking eyes, flattened back, and long ventral fin. 
It sometimes reached a length of six feet, and as the electric 
batteries occupied nearly two-thirds of the entire fish, one could 
easily understand how much it was dreaded by the natives of 
the Orinico region, and how ordinary fishes gave the Electric Eel 
a wide berth. 
The Gymnotus had four batteries—two large and two 
small—on each side of the body, supplied by about 200 pairs of 
