THE STONELESS PLUM 43 



stoneless plum was a small acid fruit growing on 

 a wild bush. 



The problem was to combine two lines of 

 ancestry that were in many respects directly in 

 conflict. It would have been impossible to do 

 this had it not proved that stonelessness and good 

 quality of fruit, although not originally combined, 

 have the attributes of what may be called unit 

 characters, and hence can be assembled in a single 

 fruit in the later generations of a hybrid progeny. 



THE ORIGIN OF THE STONE FEUITS 



A very natural question arises as to what had 

 originally caused the little French "bullace" as 

 the Sans Noyau is sometimes called to develop 

 the extraordinary tendency to give up the stony 

 seed covering which no other member of the 

 family had ever been known to renounce. 



The question is doubly significant when we 

 recall that some sort of shell or stony covering 

 is almost absolutely essential to the preservation 

 of the seeds of plants in general. The shell is 

 often very thin, as with the seeds of most garden 

 plants. It may be reduced to a mere filament of 

 cellulose, as in the case of a grain of wheat. With 

 pulpy fruits it is usually a very significant cover- 

 ing, of which the seeds of the apple and orange 

 afford typical examples. And with the great 



