$$$ :05::volt ——__——__+ 
PLANTS UNDER MECHANICAL STIMULUS. 283 
torsional vibrator. I then took a record of the responses to 
two successive taps, the intensity of one being nearly double 
that of the other (response-curves a, 6). Having done this, I 
applied to the same stalk two successive torsional vibrations 
of 45° and 67° respectively, and obtained the responses 
Fig. 6a, 
btained by taps (a, 4). 
Responses oblanees vibrations (e, d). 
” ” ” 
Current of Injury 
— 
e and d. These successive response 
are given in fig. 68, and from them i 
two modes of stimulation may be used 
effect. L - 
s to taps and torsions 
t will be seen that these 
indifferently, with equal 
