THE STOXELESS PLUM 51 



Professor Castle instances in support of this 

 view the case of guinea pigs bred by him that 

 developed a full-sized fourth toe on the hind foot 

 from a rudimentary stump of a toe. 



The experiments just cited illustrate the oppo- 

 site condition of causing a rudimentary organ 

 in this case a plum stone to be altogether 

 eliminated. 



It should not be overlooked that both experi- 

 ments are perhaps capable of interpretation in 

 other terms. In each case what actually happens 

 may perhaps be better explained as reversion 

 to a very remote ancestor. Doubtless there were 

 among the ancestors of the guinea pig races with 

 four toes; and doubtless if we go far enough 

 back we should find ancestors of the plum that 

 produced a seed having no stony covering. And 

 we are perhaps not far wrong in assuming that it 

 was the long-subordinated influence of this vastly 

 remote ancestor that, in the case of my plums, 

 sided with me, so to speak, against the forces of 

 the more recent heredity, and made barely pos- 

 sible the ultimate success of my hybridizing 

 experiments. 



THE VALUE OF THE NEW PRODUCT 



We are so accustomed to putting up with the 

 annoyance of the stone in the fruit that we for 



