120 



TRANSLOCATION IN PLANTS 



may come from cells injured by the treatment. If the 

 pigments result from injury to the cells, it is highly probable 

 that the sugars and other solutes also may get into the sap 

 for the same reason, and in still greater quantities because 

 the living cells are so rich in them. 



240 



220 



200 



180 



160 



140 



J 120 



CD 



°100 



80 



60 



40 



20 







Feb.10 March April May June July Aug. Sep\ Od. Nov. Dec. Jaa 



i t 



Full Bloom Leaves Shed 



Fig. 7. — Free reducing substances and sucrose in tracheal sap from pear branches. 



(From Anderssen.) 



Anderssen (1929) has determined the concentrations of 

 various constituents of the tracheal sap which had been 

 obtained by gas displacement from the main branches of 

 three-year-old Bartlett pear and Royal apricot trees at 

 various seasons during the year. As can be seen from 

 Fig. 7 (adapted from Fig. 6 of the paper cited), the maxi- 



