THE TOMATO 185 



it, and makes it over into its own kind of proto- 

 plasm. But we know that the flesh of animals 

 varies in quality with the food given the animal, 

 and we cannot well doubt that the protoplasm 

 of the root of a plant must similarly be modi- 

 fied by the character of its food. 



And this line of thought suggests the further 

 possibility that when more cions than one are 

 grafted on the same branch or on the same trunk, 

 there must be a certain intermingling of the sap 

 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 affect 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 influence the fruit of a neighboring stem 

 so that the seedlings that grew from that 

 fruit bore purple leaves, and smaller crimson 

 fruit. 



As before stated, such a striking instance of 

 evident "sap hybridism" is exceedingly rare; but 



