LUTHER BURBANK 



pear does not really need so much water as it or- 

 dinarily receives. 



But the effort to give the tree immunity must 

 go even deeper. Induced immunity is valuable, 

 but the ideal condition is that of inherent resist- 

 ance, bred in the tissues. 



Physicians tell us that the all-important thing 

 in warding off bacterial infections in the human 

 subject is the inherent vitality and resistance of 

 the patient himself. In the last analysis, this is 

 the prime essential. A thoroughly rugged organ- 

 ism may be immune to almost every type of bac- 

 terial disease. We are told that almost no one 

 escapes infection with the germs of tuberculosis. 

 The ones who show no evidence of the disease are 

 simply those whose tissues are so resistant that 

 the attacks of the bacilli are thwarted. 



The horticulturist must take a lesson from the 

 experience of the physician, in particular with 

 regard to the malady we are now considering; for, 

 as we have just seen, the analogy between the pear 

 blight and human infections is almost perfect. 

 So the ideal at which the plant experimenter must 

 aim is the development of a tree that will be im- 

 mune to the attacks of the bacillus, however freely 

 the germ finds access to it. 



My new hybrid pear, thanks to its Oriental 

 heritage, seems to fulfil this condition. The same 



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