QUANTITY PRODUCTION 275 



Take by way of illustration the case of our 

 stoneless plum. We discover soon that the stone 

 seed is prepotent or dominant, and stonelessness 

 latent or recessive. So we must be prepared to 

 see the progeny of our first generation of hybrids 

 ail produce common stony fruit. But a knowl- 

 edge of the tendency of latent or recessive 

 characters to reappear in successive generations 

 comes to our aid, and we go on with the experi- 

 ment with full confidence, even though for the 

 moment we seem to be going backward rather 

 than forward. 



In due course the second generation of plums 

 appears with a number of stoneless specimens, 

 the latent character having come to the surface. 

 But these lack many of the good qualities that 

 our perfected fruit must have, and in order to 

 breed these qualities into the stock we must make 

 a new cross ; and this will involve the breeding in 

 again of the tendency to bear stone fruit. 



So in three generations we shall find ourselves, 

 as regards the essential quality of the stony seed, 

 somewhat further back than we were in the be- 

 ginning. 



But, on the other hand, our third generation 

 fruit, even though it has a stony seed, has quali- 

 ties of flesh that its stoneless ancestor altogether 

 lacked; and in the fourth generation we shall be 



