4 Inheritance in the Japanese Convolvulus. Part TI 



The meaning of the factors is as follows : 



G, the factor for green colour in the leaf 



D, that for dark-red flower-colour when the accompanying G is in 

 homozygous condition ; it produces, however, scarlet colour when G is 

 present as Gg, or when it is altogether absent (i.e. gg) and B is also 

 absent. 



B, that for blue colour; in the presence of D its effects are not 

 manifest when G is present as GG ; it produces magenta colour both in 

 homo- and heterozygous condition, when G is in the condition Gg or gg. 



M, that for modifying the tone of flower-colour both iu homo- and 

 heterozygous condition, i.e. the medium grade of magenta, scarlet, or 

 dark-red colour is produced when M is present and the plant is also 

 homozygous for D ; the light grade of each of these colours is produced 

 when M is present and the plant is at the same time heterozygous for D ; 

 and finally the deep grade appears when M is altogether absent. 



The genetic constitution of each F^ plant is naturally GgDdBbMm, 

 and when it is self-fertilised we expect 81 zygotes of different genetic 

 constitutions, as is shewn in Table II. Thus we may acknowledge that 

 my hypotheses above stated will well explain all my results. It is 

 necessary to add here that though the meaning of the factor D is some- 

 what more broadened in this than in my first paper, inasmuch as not 

 only is its action intimately bound with G but also with B, nevertheless 

 my view in respect to the relation between green leaf and dark-red 

 flower-colour remains quite unchanged. 



II. Back-crossing. 



In 1916 the back-crossing of one F^ plant by both of the two 

 parents, A or B was done. 



1. FiX^ (= GgDdBbMm xggddBBMM). 



The results are shewn in Table III. 



TABLE III. 



Light miigenta White Totals 



Green ... 33 48 81 



Yellow ... 45 38 83 



Totals ... 78 86 164 



\ 41 41 



41 41 



Expected 



In this case, as was described in my previous paper, it will be seen 

 that the ratios between green and yellow plants and between light 

 magenta and white are 1 : 1, respectively; and besides, coloured flowers 



