1920] 



LANGDON—DIOOM SPIN U LOS UM 



121 



Discussion 







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I 



t 



In his description of the girdling habit, Mettenius (io) finds 

 that "in the developmental stage the traces of the youngest leaves 



Fig. 12. — Detail of organization of cortical foliar strands of three-year-old plant. 

 ht, horizontal strand in transverse section; 1st, longitudinal section of vertical lateral 

 trace near point of union with horizontal strand; x, primary sylem ; x 2 t secondary 

 xylem; ph, prima ry phloem; ph 2 , secondary phloem; X120. 



lie in the region of the vegetative point, and at first ascend in an 

 almost perpendicular direction, but during further growth assume 



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