LUTHER BURBANK 



remained as part of its heritage — there would 

 probably have been no very great difficulty in 

 producing through hybridization a stoneless fruit 

 of good qualitj' in the second or third generation. 



All experiments seem to show that the stone 

 condition is, as might be expected, prepotent, or, 

 in the Mendelian phrase, dominant. 



So in crossing an ordinary plum with a stone- 

 less one, it was to be expected that the offspring 

 of the first generation would bear stone-fruit. But 

 the latent or recessive trait of stonelessness may 

 be expected to reappear in a certain proportion of 

 the offspring of the second generation; and the 

 stoneless fruit thus produced may be expected to 

 breed true. 



Such is what might be expected provided one 

 were dealing with an absolutely stoneless plum 

 as one of the progenitors. 



But unfortunately we are not dealing with an 

 absolutely stoneless plum, but only with one in 

 which the tendency to produce a stone has been 

 minimized or partially suppressed. And so our 

 relatively stoneless plum of the second generation 

 still retains traces of the hereditary propensity to 

 produce the stony covering; and, as we have seen, 

 this propensity manifests itself in the fragmentary 

 stone, sometimes reduced to a mere speck in size, 

 that many of my stoneless plums exhibit. 



[122] 



