50 LUTHER BURBAXK 



But unfortunmlely wc are not dealing with an 

 ab«ioItiteIy stonelcss plum, biit only with one in 

 which the tendeDcy to produce a atonr Has been 

 miniraiBcd w partially suppreMcd. And so otir 

 rcUtively atooeleiB plum of the aecond ^'rnem 

 tion still retains traces of the hereditary propen 

 lity to produce the ston\ «n<I. as we 



hare seen, this propensity nuuuicsu itself in the 

 fragnicntary stone, sometimes reduced to a niere 

 speck in sixe, that many of my stondcsi plums 

 exhibit 



Xe^'ertheless there remains not a doi 

 from subsequent generations, from the mcx-. 

 in hand, an ab»nlutely stonelcss plum that 

 retains all the valued qtulities of tlie fruit and 

 in all staes, colors, and flavors desired will b< 

 produced. 



That it has been possible to climm-t*" '^^ v« rr 

 altogether, advancing thus markc 

 gard upon the original partially stoneless form 

 with which the experiment began, suggests the 

 truth of a view now held by some pr< * 

 biologists, notably by Professor Willia... L 

 Castle of Harvard, that a unit character ma\ 

 be modified in successive generations — not 

 merely blended or made into a mosaic with 

 other charac^ - hut actually modified as to 

 its potential ... 



