— 130 — 



In the same way in Position 2 the curvature would be in 

 direction C if the cotyledon is geosensitive, but upwards in direction H, 

 if the hypocotyl is independently geotropic. But in Position 2 there 

 was no such regulär occurrence of curvatures in direction (', the 

 results were irregulär bendings in both directions. 



This difference between Positions 1 and 2 seems to depend 

 on the fact that in Position 2 curvature C (i. e., the movement 

 which should result from the Stimulus of the cotyledon) is in Oppo- 

 sition to the direction of the forced bend in the cotyledon, while 

 in Position 1, curvature C is in the direction of the curve in the 

 cotyledon. 



l 



Fig. 6. Position 3. 



It seemed possible that the artificial curvature in the cotyledon 

 causes a growth-curvature of the hypocotyl in the same direction. 

 We have evidence for this, and there is no inherent unlikelihood, 

 for this is whatWachteP) observed in his repetition of Czapek's 

 glass-boot experiment. 



if this is so, then in position 1 the cotyledonary Stimulus 

 (producing a curve in direction C) acts with the traumatic effect; 

 in Position 2 the traumatic effect acts against curve C. Therefore 

 we should expect curve C to be more uniform in occurrence and 

 greater in amount in position 1, than in position 2 — and this is 

 so far what is found. 



When the cotyledons are forcibly bent, not as above described, 

 but by pushing them into bent glass tubes, the traumatic effect 

 seems to be stronger. Thus, out of 6 experiments in position 2, 



') M. Wachtel, Bot. Zeitung, 1899, p. 223. 



