126 LUTHER BURBANK 



And when we advance from five pairs of unit 

 characters to ten or twelve, as we have already 

 seen that we must do in the case of our cherry, 

 the matter becomes almost infinitely complex. 

 As we increase the number of qualities under 

 consideration, the number of possible combina- 

 tions among them increases at an alarming 

 geometrical ratio. 



It appears that whereas there is an even 

 chance, when only a single pair of qualities was 

 in question, of producing one offspring like each 

 parent in each group of four; and whereas there 

 is the same even chance of producing one off- 

 spring like each parent in every group of 256 

 individuals when four pairs of unit characters 

 are in question when we have to deal with ten 

 pairs of unit characters the possible arrange- 

 ments have become so bewildering and complex 

 that there is even chance of producing a single 

 offspring like each grandparent only in each 

 group of more than a million progeny! 



QUANTITY PRODUCTION NECESSARY 



Such a computation, as made in accordance 

 with the Mendelian formula, in itself serves to 

 supply a ready answer to those Mendelians who 

 have questioned the necessity of making experi- 

 ments on the elaborate scale that I have all along 



