LUTHER BURBANK 



most of them retain more or less conspicuous 

 flowers proves this beyond question. In the case 

 of the wheat, which might be thought a possible 

 exception, there is the evidence of certain species 

 of wild wheat, growing to this day in Palestine, 

 which have only partially renounced allegiance 

 to the insects, still putting forth flowers that on 

 occasion may be cross-fertilized with their aid 

 or with that of the wind. 



Just why these various plants of different 

 families have departed from the custom that has 

 served their fellows so well, would be interesting 

 matter for conjecture. 



Perhaps the most plausible suggestion is that 

 the ancestors of the plants that now have 

 closed flowers and thus depend exclusively upon 

 cross-fertilization had fallen on evil days in which 

 there was a dearth of insect messengers in the 

 regions they inhabited. 



The story of the starved martins, told in an 

 earlier chapter, furnishes a striking illustration of 

 the fact that insects that ordinarily are abundant 

 may in any given season fail to put in their 

 appearance. 



And even if the insects themselves are abun- 

 dant, the weather conditions, in a given season, 

 may be such as to make it almost impossible for 

 them to carry out their bargain by transferring 



[74] 



