124 BOTANICAL GAZETTE [SEPTEMBER 
if the opposite be true, very little if any of the current will pass 
through the organism. It is very evident that, since the conducting 
power of the medium is vastly increased by small amounts of 
electrolytes, the conductivity of the liquid is an ever-changing 
value. It is likewise evident that the same objection applies to 
roots in water through which the current is passing. Furthermore, 
the literature of electro-physiology is filled with references to cur- 
rent strength as weak, medium, strong, or with the mere statement 
of the number of cells used, with no statement of resistance in the 
circuit, so that actual current intensity cannot be determined, and 
difficulty is experienced in even approximating the conditions of 
the experiment. With the materials and methods just described 
these difficulties are avoided. 
Observations 
KILLING EFFECT OF CURRENT 
If a seedling with a root of 15-20 mm. in length and of 0.7-0.9 
sq. mm. in cross-section is exposed in the manner described to a 
current of o.3 milliampere, the following changes take place. In 
about thirty seconds the root begins to lose its normal color and 
' becomes watery in appearance. If the current is continued for 
two minutes or longer, numerous very fine droplets of liquid appear 
over the surface 3-6 mm. from the tip. If the current is now 
stopped and the root tip tested, it will be found to be quite flaccid. 
Furthermore, measurement shows that the root is now from 0.5-1.0 
mm. shorter than before the current was passed. An exposure of 
a longer period than two or three minutes results in the root becom- 
ing more or less translucent, and on testing after such longer 
exposure it is found to have become even more flaccid. In the 
preliminary experiments roots were treated with varying amperage 
and for different time periods, then fixed, sectioned, and stained. 
While the cytological pictures were similar except as to degree of 
intensity of results, they were not comparable with each other; for 
example, it was difficult to produce the same result with a 0.4 milli- 
ampere current and a o.5 milliampere current by varying the time. 
After much experimentation, in an effort to arrive at somewhat 
comparable cytological results, had ended in failure, it was found 
