QUANTITY PRODUCTION 271 



This selected seedling he may nurture and use as 

 part of his equipment for further experiment 

 just as you retained the letter "E" as marking 

 the beginning of your success in spelling the word 

 "evolution." 



And as the plant developer continues his ex- 

 periment with successive crossings and succes- 

 sive selections, he will be able in later generations 

 to find individual seedlings that combine succes- 

 sively more and more of the qualities he is seek- 

 ing. When, finally, he reaches the stage where 

 the parent forms have between them all the de- 

 sired qualities in superlative degree, he is some- 

 what in the position that you were in when only 

 two of your lettered blocks remained in the bag. 

 There is at least an even chance that he will find 

 among his seedlings of the next generation one 

 that will approximate his ideal, even though the 

 number from which he selects is far smaller than 

 the earlier groups. 



Thus by advancing step by step and using 

 the ground gained as a new starting point the 

 experimenter attains his end with comparative 

 celerity, even though there would have been 

 scarcely more chance of attaining that end with 

 a single experiment than you would have had of 

 spelling out the word "evolution" at a single 

 series. 



