73 7 
1885.] Electric Organ of the Torpedo. 
gymnatus and the torpedo the elearic organs are developed 
in the very directions which fresh water and salt water 
respectively require ; how the eleCtro-motive forces of both 
these fishes are found, on measurement, to be approximately 
what the resistances of fresh water and of salt water require ; 
how the positive polarisibility of the organ is adapted to 
increase the stroke by rapidly succeeding shocks, whilst the 
negative effects by tetanisation, the objeCt that a new dis- 
charge begins again almost from null. I proved the neces- 
sary immunity against eleCtric shocks possessed by these 
fishes and their spawn. Lastly, the remarkable nerve 
tufts discovered by Wagner in the organ of the torpedo 
seemed possibly to have the power of causing all the 
elearic plates innervated by the same primitive nerve fibre 
to come simultaneously into aCtion. In one point only 
we failed to understand the arrangement of the elearic 
organs of the torpedo : the part of the external space 
above the back of the fish, bordering on the sagittal plane, 
though most in need of proteaion, seemed to us, in the 
language of military engineers, a “ dead angle. This evil 
is, to a certain extent, undoubtedly obviated by irreciprocal 
conduaion.” 
“ However this may be, the instance of internal pur- 
posiveness which we have found sui passes in ingenuity, so 
to speak, all the former. It would certainly have required 
the most profound meditation of a gifted thinker to suggest 
the idea of making each column a good conduaor for its 
own current as far as the general properties of animal 
tissues permit, but comparatively a non-conduaoi for the 
current of all other columns. Not the least clever point is 
that since the shock of the elearic fishes is quickly 
transient the organ conducts inecipiocally only, brief 
currents. These would have no use in lendeiing it 
a perfect non-condudftor for permanent heteiodiomous 
currents. 
The distribution of elearic force in the organic world 
is a mystery. We have an elearic plant, an electric 
bug, an elearic slug, and three elearic fishes. . vVhy 
this power should not occur in other forms of life is not 
understood. 
