170 



curvatures after 40, then after 90 minutes. Afterwards I 

 compared with one another the results obtained after 50 

 and 80 minutes, and so on. Therefore Table I does not 

 give the séquence in which the experiments were done. 



A. Geotropic experiments with seedlings of Avena. 



TABLE 1. 

 Strength of stimulus 900 mg.-secs. Température 20° C. 



