BLAZE-CURRENTS OF VEGETABLE TISSUES. 47 
$30. A sufficiently obvious fallacy may arise from this source. 
Suppose we have a quite young pea on the electrodes, with 
a fresh-cut surface at B, so that the current of injury is positive: 
the resistance is very high, the deflection is small, and we have 
to use a considerable voltage from the compensator in a negative 
direetion in order to bring the spot back upon zero. A strong 
induetion-shoek is now sent through the pea in the negative 
direction, the after-effect of which is a large deflection in that 
same direction. We find that the resistance is greatly diminished, 
and the large deflection to the left may evidently be due to our 
large compensating voltage. While the resistance was high, 
we might easily have over-compensated; so that the over- 
compensation would come into evidence when the resistance 
was reduced. Of course, to do this, the alterations of resistance 
would need to be very great. And they are so,—it is not 
uncommon to see the resistance reduced to yy of its original 
value by a single strong induction-shock. 
$ 31. I have seen the fallacy in another form. A young pea, 
with its base cut, has a current of injury in the positive direction 
which, by reason of the enormous resistance, gives a barely appre- 
ciable deflection. A single induction-shock is sent through the 
pea in the positive or in the negative direction; an apparent 
blaze-current is manifested in the positive direction, which, how- 
ever, I do not consider to be a true blaze-current, but only a 
deflection due to the positive current of injury through a suddenly 
diminished resistance. 
$32. The different behaviour of young peas and old arouse 
many reflections. The old are conductors ; the young are non- 
conductors. Conduction is by electrolytes. Salts—or their 
ions—are electrolytes par excellence. Are there more salts in old 
peas thanin young? And what is the meaning of Loeb’s recent 
investigations into the influeuce of salts upon the development 
of ova? I have no means of reply; so the questions must 
wait. 
$33. The Holly-leaf expertment.—Here is a curious ex- 
periment on resistance, with a holly-leaf. I say curious, because 
it has aroused my euriosity, and I cannot rest satisfied with the 
explanation that offers itself. 
The leaf is placed between the electrodes as usual, in series 
with the galvanometer and secondary coil. I send an induction- 
