>» “+4 On oe 
THE ELECTRIC ORGANS OF FISHES. 65 
expressed surprise had it been suggested that there was 
considerable diversity in the form and structure of the electrical 
apparatus of the various members of the Skate family. The 
discovery of the existence of the electric organ of the Skate 
was due to Dr. Stark, of Edinburgh, who read a paper on the 
subject before the Royal Society of Edinburgh in 1844, but 
having been labelled by naturalists ‘‘ pseudo electric,” it had 
been until quite recently neglected alike by physiologists and 
naturalists. But the Skate’s organ was coming to the front 
again on account of the light it threw on the development of 
the powerful battery of the Torpedo. ‘The discharges from the 
Skate’s batteries, though weak, and, as far as had been 
ascertained, useless, behaved exactly like the discharges from the 
Torpedo. The Skate did not keep its electric battery at each 
side of the gill like the Torpedo, but carefully tucked away in 
the tail. 
He described at length the structure of the electric organ of 
the Skate. Instead of consisting of a series of plates, it 
consisted of a series of discs, or cones, fitted into each other 
like thimbles, and forming a long electric spindle. Each disc 
consisted of several distinct layers. The first layer, into which 
all the nerve fibres pass, was not unlike the electric plate of the 
Torpedo. Altogether in the electric organ of the Skate there 
might be 25,000 discs, or 50,000 in the two electric spindles. 
In other Skates, instead of the discs, there were numberless 
cups, each cup having led into it numerous nerve fibres. He 
further showed that in other instances the electric organ was 
composed of muscular cups; and in the young of the Skate 
the process of development of the. muscular tissue into the 
electrical organ was traced. 
In the same way, he said, the electric organ of the Torpedo, 
notwithstanding its extreme complexity and remarkable powers, 
had been formed out of ordinary muscular fibres. For some 
inscrutable reason, the fibres of certain muscles concerned in 
moving the jaws of the ancestral Torpedoes became more and 
more modified, generation after generation, until they entirely 
lost their original function, and were so profoundly altered 
in structure that it was no longer possible to recognise in them 
the remotest resemblance to muscular tissues. But though he 
had been able to show that the Torpedo’s electric organs had 
