HARDENING AND ADAFfATION 



The problems that arose in this line of work 

 lere among the most difficult he had ever 

 jncountered. Very much had to be taken into 

 iccount, — the past of the tree, not only imme- 

 liate but remote, its failures and successes 

 mder different environment influences, its 

 limitations, its need of new blood by crossing 

 )r the restoration of its depleted veins through 

 selection. For Mr. Burbank had come to look 

 [upon all plant life as being very closely allied 

 to the life of man, open to many similar 

 ittacks, subject to many diseases, needing the 

 :een eye of the physician and the dietarian, 

 responding to heat and cold, light and shadow, 

 lactivity and exercise. He early recognized, 

 too, the importance of transference, the intro- 

 fduction of a fruit from a distant quarter of the 

 globe, engrafting its life upon the life which 

 was not coming up to its opportunities. He 

 recognized that that which holds true in the 

 human race, — that admixture of blood is desir- 

 able, indeed is imperative at intervals, in order 

 to prevent such physical decadence as follows 

 the intermarrying of royal families, — held 

 true sometimes in the vegetable world; there 

 were certain families that needed new blood 



)9a 



