366 Darwin, and after Darwin. 
of its generating a sufficient amount of electricity 
to yield a discharge that can be felt by the hand 
Nevertheless, that it does discharge under suitable 
stimulation has been proved by Professor Burdon 
Sanderson by means of a telephone; for he found 
that every time he stimulated the animal its electrical 
discharge was rendered audible by the telephone. 
Here, then, the difficulty arises. For of what conceiv- 
able use is such an organ to its possessor? Wecan 
scarcely suppose that any aquatic animal is more 
sensitive to electric shocks than is the human hand ; 
and even if such were the case, a discharge of so feeble 
a kind taking place in water would be short-cir- 
cuited in the immediate vicinity of the skate itself. 
So there can be no doubt that such weak discharges 
as the skate is able to deliver must be wholly imper- 
ceptible alike to prey and to enemies. Yet for the 
delivery of such discharges there is provided an organ 
of such high peculiarity and huge complenity, that, 
regarded as a piece of living mechanism, it deserves to 
rank as at once the most extremely specialized and 
the most highly elaborated structure in the whole 
animal kingdom. Thousands of separately formed 
elements are ranged in row after row, all electrically 
insulatcd one from another, and packed away into the 
smallest possible space, with the obvious end, or 
purpose, of conspiring together for the simultaneous 
delivery of an electric shock. Nevertheless, the shock 
when delivered is, as we have just seen, too slight to 
be of any conceivable use to the skate. Therefore it 
appears impossible to suggest how this astonishing 
structure—much more astonishing, in my opinion, 
than the human eye or the human hand—can ever 
