146 CHAP. XIII. DIA-PHOTOTROPISM 



Table XVI. Effect of Unilateral Light on the Root 



OF SiNAPIS. 



O 20' 40' 6O' 



€ 



Time 



Fig. 83. Response of root of Sinapis under continued unilateral 



action of light. 

 The sequence of response is positive, neutralisation, and 



pronounced negative. 



then moves away from it, passing through the stage of 

 neutralisation, 



