THE CHERRY 147 



Hybridizing with some wild species, intelli- 

 gently and systematically carried out, might 

 produce varieties of cherry that would show ex- 

 ceptional resistance to insect pests as well as 

 inherent vitality that makes for vigor in the tree. 



It has long been my belief that a solution of 

 the problem of protecting our fruit trees from 

 both insect and fungus pests must eventually be 

 found in the development of the qualities that 

 make for immunity of the trees themselves, 

 rather than in the resort to such expedients as 

 spraying and "gasing." In this regard the plant 

 experimenter may well take a leaf from the note- 

 book of the physician, who has learned that im- 

 taunity to disease often depends more upon the 

 condition of the patient than upon the presence 

 or absence of disease germs. 



It is possible, furthermore, that the cherry may 

 be hybridized even more widely, and that a fruit 

 differing markedly from any cherry hitherto pro- 

 duced may thus be developed. An inkling of the 

 possibilities in this direction is given by some ex- 

 periments made recently by Professor N. E. 

 Hansen, of the South Dakota Experiment Sta- 

 tion, who has cultivated a variety of wild fruit, 

 called the Sand Cherry, Prunus besseyi, which 

 is a dwarfed, compact grower, of heavy form and 

 good foliage, and which had previously been put 



