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seedlings, in conséquence of the lengthy absence of oxygen, 

 are unable to perceive a phototropic stimulus. 



À stimulus in ordinary air, after a long fore-period in 

 nitrogen, is indeed perceived, the plant seems however 

 to hâve lost a part of its power of perception, as is shown 

 by the curvatures being smaller than when the whole 

 process takes place under normal conditions. 



