66 



I. XAGAI ; 



practically uo oln-omogeuic substance whereas the rest of them is prominent. 

 This is t) inrlicate that a dominant inhibitor is present in the green and 

 yellow. Let G be the gene for the gi-een colom' and g for the yellow. Fur- 

 ther we assume that C and c are the chromogeus. Tlie amount of chromo- 

 genic substanci produced by c is less than that produced by C. Let be 

 the clu'omopheleiu which converts the chromogenic substance to brown pigment 

 and o to reddish brown. It is assumed that the same chromogenic substance 

 is converted to the purple anthoeyanin by B but not by r. The gene I 

 inhibits the fuU development of the pigment in the seed coat and by i no 

 such effect is done. The iuliibitory action of the gene / seems to extend to 

 the action of C and R. Accordingly the different colour tj-pes may be de- 

 signated as follows : 



The genetic composition of tlie parental plants of the cross between 

 "Haiü-o" and "Tanishi" would be CCOOGGmi and CCOOggRRII re- 

 spectively. Tlie F^ plant is therefore heterozygous to three genes Gg Rr and 

 /(■ but homozygous to C and 0. The different phenotypes appeared in F. are 

 due to the recombination of these genes. Thus : 



