576 



BOTANY OF THE LIVING PLANT 



above (p. 574), we should expect the F x plant from such a cross to be pink- 

 flowered. This is actually the case, and in addition the flowers are all 



Fig. 438. l»J 



" Dihybrid " Segregation. Cross between an Ivory, Normal (1) and a 

 Crimson, Peloric (2) Snapdragon. (3) =F X (Pink, Normal). 4, 5, 6, 7 : 

 four out of the six F 2 phenotypes (in the diagram no distinction is made 

 between pink and crimson flowers — see text). (After E. Baur.) 



zygomorphic, the normal flower-form being fully dominant to the peloric form. 

 In F 2 six phenotypes appear, namely : Iq the ratios of 



Crimson, Normal - 



Pink, Normal ... 



Crimson, Peloric - 



Pink, Peloric - 



Ivory, Normal - 



Ivory, Peloric =. 



i\ths 



rVths 



rVth 



Aths 



i^ths 



} 



3 



J-th 



1^ 



