624 



Hie tU'tioii of this process becaine evident aftei- a certain period of 

 pi'eliininarj illumination by the disappearance of the possibility of 

 inducing negative curvatures and the exclusive appearance of positive 

 ones. 



§ 5, The f(idliu) phenomenon {"Abklingen"). 



Onmilateral preliminary illuminations render possible the closer 

 study of a |)henonienon, which is generally called fading of 

 an excitation. By omidlateral stimulation of a plant for a longer 

 or shorter time we obtain as response a certain insensitiveness. We 



TABLE VI. 

 Fading of an omnilateral preliminary illumination. 



During 100 sec. omnilateral fore-illumination with an intensity of 25 C. M. 



TABLE VII. 

 Fading of an omnilateral preliminary illumination. 



During 20 minutes omnilateral fore-illumination with an intensity of 25 C. M. 



