158 The Botanical Gazette. [May, 
ing off of CO,. 5. Dessication acts in the reverse manner 
and, by diminishing the permeability, decreases the oxygen 
and tends to the storing up of a greater proportion of CO,. 
6. The nitrogen is passive and is carried as a by-product wit 
the others. 7. e general conditions of gaseous interchange 
upon the undoubted fact that there are three different kinds 
of interchange going on simultaneously, each of which is cap- 
able of modification by external or internal conditions. These 
are diffusion, effusion and dialysis. —CONWAY MACMILLAN. 
Effects of electricity on growth.’ 
In this paper Hegler has described the effects of electricity 
on the growth of plants. In it he has shown that certain 
Plants respond to electrical stimuli in a similar manner ay pe 
do to light. In his experiments he used an apparatus like ae 
park. 
“or these experiments Hegler found the rapidly a 
aerial hyphe of Phycomyces nitens particularly well adapt 
as It is well known that they are exceedingly sens! 
external influences. The plants were cultivated on § 
bread : inder to preve 
rac and covered with a black paper Te the hy- 
tains they are negatively electrotropic. The angle o 
however, he found somewhat smaller than that pro 
Intense light. Herr Hegler also experimented with © 
rays, both from a plain and parabolic metal reflec 
which he obtained similar results. 
age 
oe eee "schen 
ER:— Ueber die physiologische Wirkung der Hertz’s¢ 
eipzig. 
Sy Rosert Heo. 
tricitetszellen auf Pflanzen. [, 
