228 



BREEDING 



to exist. In this case the theory is in advance of 

 our knowledge ; it is not yet known whether these 

 three types do exist. But this can be easily deter- 

 mined by mating all the whites which occur in such 

 a second hybrid generation with pure pinks. Let 



US see what will be the result of mating the three 

 types of white with pure pinks the formula of 

 which would be PPbb. 



The single white homozygous for blue with the 

 formula ppBB (No. 11)* will be considered first. The 

 union is of this type. The pink produces only 

 one kind of gamete, Pb, and the white also 

 produces only one kind, pB ; the result of their 



♦ See Table on p. 226 or p. 229. 



