ON THE TOMATO 



from the different leaf systems in the course of 

 the journey to the roots of the tree; and that it 

 might very conceivably happen that a sufficient 

 blending would take place so that the modified sap 

 might find its way to the fruit buds of a given cion, 

 and effect the character of the fruit in a way not 

 altogether unlike the effect of hybridizing. 



This would account for the case narrated at 

 length in an earlier chapter, in which a cion of 

 the purple-leaved plum grafted on the stem of a 

 green-leaved Kelsey plum tree, appeared to influ- 

 ence the fruit of a neighboring stem so that the 

 seedlings that grew from that fruit bore purple 

 leaves. 



As before stated, such a striking instance of 

 evident "sap hybridism" is exceedingly rare; but 

 can we be sure that influences of a less tangible 

 character are not constantly exerted by engrafted 

 limbs? 



May it not be possible, even, that the influence 

 of cions from many sources on one another, when 

 they are placed together in large numbers on a 

 single tree, as in the case of my colonies of plums 

 and cherries and apples, may be very notable 

 indeed, even though of such character as not to be 

 demonstrable? Is it not at least possible that the 

 improved quality of the new and splendid varieties 

 that appear on the various cions of these multiple 



[143] 



