128 



Plant Genetics 



Of course complementary 

 factors can exist together in 

 a gametophyte. A gameto- 

 phyte could not contain Aa 

 (allelomorphs), but it could 

 contain both A and B, 

 which may be comple- 

 mentary factors. 



It is evident also that 

 supplementary and inhibi- 

 tory factors are also possible 

 in gametophytes, just as are 

 complementary factors, for 

 they are not segregated by 

 the reduction division. Of 

 course a gametophyte show- 

 ing an entirely new char- 

 acter produced by the 

 interaction of two comple- 

 mentary factors would have 

 to be a gametophyte grown 

 from a hybrid sporophyte 

 in which these two factors 

 had been brought together; 

 and the same is true in 

 reference to supplementary 

 and inhibitory factors. 

 With these facts in mind the 

 validity of our theoretical 

 mechanism could be tested. 



Finally, the case of 

 cumulative factors could be 



