190 



Even without collectury the results in a table, it is at 

 once seen that a fore-period of 3 hours has as little efFect 

 as in the geotropic experiments. If the fore-period lasts 

 6 hours then the influence is undoubtedly noticeable, 

 because the reaction is considerably weaker, whilst it 

 remains entirely absent when the seedlings before stimula- 

 tion hâve been for 8 hours in a nitrogen atmosphère. 



From ail thèse experiments it follows therefore that 

 the seedlings must be deprived of oxygen for a considérable 

 time in order that a reaction may be completely inhibited. 

 There are clearly two possible explanations of this: 

 1. It is possible that the objects of experiment in 

 conséquence of intramolecular respiration hâve sufficient 

 energy at this disposai to enable them, after a long time, 

 albeit to a lesser degree, to perceive a stimulus and exécute 

 a reaction, when after stimulation they hâve again been 

 supplied with atmospheric air. 



