22 



TRANSLOCATION IN PLANTS 



sperms. I have found it a simple matter to cause starch 

 deposition in twigs lacking starch by injecting sugar 

 solutions (Curtis, 1918). 



1 2 3 



Fig. 1. — Drawing to indicate methods of treatment to study the effects of 

 rings on upward movement of carbohydrate or of nitrogen when the movement 

 of water through the stems is similar in all cases. R indicates the positions of 

 rings. In some experiments rings were also placed at R' . In all cases ring 

 wounds were protected with melted paraffin and the stems were of course 

 attached to the parent plant. For experiments invoh-ing use of this method of 

 ringing see pp. 30, 50, 200, 239. 



Not only was it found that starch removal from a piece 

 of stem is prevented if that part is isolated by double rings 

 but it was also found that, if the stem lacked starch at the 



