DAILY MOVEMENT DUB TO THERMO-CJEOTROPISM ^>i)7 



this new state of geotropic equilibrium, the leaf gave the 

 record of clown-movement during rise, and up-movement 

 during fall of temperature, movements which in reference 

 to the plant are the very opposite to those in a normal 

 position. But seen from an [external point of view, rise 

 of temperature caused in both normal and inverted 

 positions, a down-movement indicative of diminished 

 geotropic curvature ; fall of temperature, on the other hand, 

 brought about an erectile movement, thus exhibiting 

 enhancement of geotropic curvature. 



Experiment 213. — A still more striking result exhibiting 

 the phase of tfan?ition was given by the geotvo])ically 



Pig. 204. — Effect of inversion of the plant on diurnal movement, (a) 

 Normal record, (6) lecoid 24 hours after , inversion and (c) after 48 hoars 

 ( TrojKPul'i tit) . 



curved stem of l^rojtceolum. Its diurnal curve and the subse- 

 quent changes after inversion are given in figure 204. In 



41 



