PLANTS UNDER MECHANICAL STIMULUS. 289 
with its opposing impulse was received. There is thus a 
diminution of height in the resulting response. The original 
rhythm of one minute was now restored and the succeeding 
curves at once show increased response. 
Fig. 11. 
“ 
a 
Fatigue in Celery. 
Fig, 12. 
Fatigue in Cauliflower-stalk. 
From what has just been said, it would appear that one of 
the main causes for diminution of response or fatigue is the 
residual strain. This is clearly shown in figs. 11 and 12. It 
