No. 626] FACTOR BELATIONS IN MAIZE 



245 



gradate somewhat into purple and there may be a ten- 

 dency to include reds among purples. If this were the 

 case, however, wrongly classified purple seeds should 

 sometimes give all red progeny or red and white progeny 

 in the next generation. East and Hayes found no cases 

 of this kind. The possibility of linkage between the P 

 and C factors should be kept in mind until this point can 

 be definitely settled. 



Other Factorial Relations 

 Looking over East and Hayes's data for other cases of 

 linkage or independence of factors there seems to be good- 

 evidence that the C aleurone and E aleurone factors are 

 not linked, and also that the factor for sweet endospema 

 is not linked with either the R or P aleurone factors. In 

 a factorial analysis of the characters of an organism with 

 reference to linkage it is just as important to know the 

 cases where no linkage is shown as those cases where it is 

 shown. Collins and Kempton (1913) give data which in- 

 dicate independence between sweet and waxy endosperm 

 factors and in another paper (1917) independence he- 

 tweenthef?n/imfa and ycnunsn fnctt^rs. Kn^t (1910) gives 

 data which indicate that tlu- two f;u'r(»r> U)v yi^llow endo- 

 sperm color are not linked with c.-icli otlirr nii«l it is quite 

 probable that both of them are indfpciidont of the factor 

 for sweet endosperm. 



With this evidence we can attempt a lieiiiiiiiing at an 

 analysis of the factorial relations in maize. Three inde- 

 pendent groups of factors can be tentatively in-oposed as 

 follows : 



Ww Endosperm Ge Chlorophyll Bs Endosperm 



Cc Aleurone LI Chlorophyll Tt Tunicate 



Pp Aleurone (?) Rr Aleurone 



The fact of no linkage between the Cc nleni one and the 

 Rr aleurone color factors separate^ uroii}!- I and II. No 

 linkage between Ww and Ss endo>pt'i iii factor- separates 



