310 



University of California Publications in Agricultural Sciences [Vol. 3 



On May 4, 1916, a large number of ;)pi)areiitly healthy terminal 

 fruits about one-half inch in diameter were selected on six trees at 

 Edison. Lot A was left as a cheek, lot B was treated by clipping off 

 with scissors one-third of the leaves of the current season's growth 

 liehind the fruit. Lot C suffered excision of two-thirds of the leaf area, 

 and lot D had all of the leaves removed, leaving the fruit terminating a 

 bare stem about six inches long. Unfortunately, a few of the limbs 

 in these trees were removed by tree primers. On November 16 the 

 remaining labels were located and a record made of the number of 

 fruits which persisted to maturity. 



TABLE 6 

 Effect of Reduction of Adjacent Leap Area on Abscission 



A. Checlv, not treated 



B. One-third leaf area removed.... 



C. Two-thirds leaf area removed 



D. All leaves removed 



Thus we see that the reduction of adjacent leaf area had no effect 

 on the drop and inasmuch as eosin solution was drawn through oranges 

 in situ to the stem in lot D very nearly as quickly as in lot A, it is 

 evident that the tensions referred to have to do with the tracheal 

 system as a whole, as is to be expected, and do not tend to be localized 

 ill any particular part of the tree. 



TABLE 7 



Presence of Lithium Nitrate in Leaves Behind Fruits Injected with 



Dry Crystals as Shown by the Spectroscope 



Experiment began at 12 m. 



