574 Life movements in plants 



i.e., a positive curvature. On the stoppage of light the up- 

 movement continued for one minute and twenty seconds, 

 after which the down-movement of recovery was completed 

 in six minutes and twenty seconds (Fig. 207). The imme- 

 diate after-effect is thus a movement upward, away from the 



Fig. 2(J7. Fui. ■2Ji Fiw. 209. 



Fig. 207. — Light applied at arrow, and stopped at the second arrow within 

 a circle. After-effect of pre-maximum stimulation is continuation of positive 

 curvature followed by recovery. 



Fig. 208. — After-effect at maximum ; recovery towards zero po.sition of equili- 

 brium. 



Fig. 209.— After-effect at post-maximum is a rapid overshooting below the 

 position of equilibrium. Light was applied in all cases on upper half oE palvinua 

 of terminal leaflet of Desinodiuin gyrans. 



zero line of equilibrium. The result is seen to be the same 

 as the electric after-effect of pre-maximum stimulation. 



After-effect at maximum : Experiment 218. — Application 

 of light for 5 minutes and twenty seconds induced a 

 maximum positive curvature. Stoppage of light was followed 

 at once by recovery which was completed in about 10 

 minutes (Fig. 208). 



After-effect at post-maximum : Experiment 219. — As the 

 plant was fatigued by previous experiments, a fresh speci- 

 men was taken and light was applied continuously on the 



