781 



growth does not occur rapidly Imt gradually, and concludes: 

 "Neben dieser allnialilichen Verscliicbiuig- der WachstlHunsschnelligkeit 

 scheint durcli einen plötzliclien lieleiiclilLingsweclisel der Regel nacli 

 keine aufTallige transitorisclie Reaktion vcranlassi zii werden". 



Tiiese conceptions, which contrast with the pholo-growtii-reaction 

 now demonstrated in Pkycomijces, are caused by various facts : 

 that very large quantities of light were used, which greatly exceeded 

 the optimum ; that the illumination was very prolonged, so that the 

 plant partly adjusted itself again to the light; that the illumination 

 was frequently intermittent, so that the phenomenon was not analysed, 

 but became more complex ; and because observations were nuide 

 at too great intervals, so that the values for a possibly accentuated 

 reaction were lost in a more average value. 



TABLE IV. 

 From 1.1 '2 p.m. to 1.2' 2 p.m. unilateral. 

 Illumination with 14 metre candle power for 60 sec. 



1.371/2 p.m. 



1.51'/2 



1.581/2 

 2. IV2-2V2 

 2. 5'/2 

 2. 7 

 2. 9 



2. 11 ','2 

 2. 131 2 

 2.151/2 

 2. 171 2 

 2.191/2 



40 



55 

 62 

 Illumination 

 68 

 71 

 75 

 78 

 80 1/2 

 [821/4] 

 [84 } 

 [851/2] 



1.07 

 1.00 



0.85 



2.00 



2.00 



1.20 



1.25 

 [0.88]*) 

 [0.88] 

 [0.75] 



Begin, of pos. curvature. 

 Increasing curvature. 



*) From ttiis time onwards tiie amount of growth is uncertain on 

 account of the occurrence of the curvature. 



