THE INTERACTION OF GENES: THE EFFECTS 



171 



18 R 

 A 



I8R+9B 

 D 



27R + I8B 

 F 



/ 



9R+9B 

 C 



18R+18B 



E 



24R + 27B 

 G 



Fig. 81. Polyploid Hybrids of Radish and Cabbage. — A shows the seedpod 

 of radish, 6 that of cabbage, C the diploid, sterile, hybrid. £ is the tetraploid 

 hybrid, D is a triploid with two sets of radish and one of cabbage chromosomes, 

 F is a pentaploid (three radish, two cabbage) and G a hypoploid hexaploid 

 (three cabbage and rather less than three radish). Note how the character of 

 the pod depends on the proportion of radish and cabbage chromosomes. 



(From Hurst, after Karpechenko.) 



