64 THE BOTANICAL MAGAZINE. LVoi. xxxiv No. 401. 



as the chromogen for tlie magenta pigment. The latter will be formed 

 by the action of a reducer upon the former. The id, concerned in the 

 formation of this chromogen, was denoted by C and its absence by c. 

 The petals of the individual, which lacks C, i.e. those of cc is 

 white. 



3. There are two kinds of the white-flowered individuals. The 

 one is represented by ccRR, and the other by ccrr. * Here the id R is 

 related to the formation of the reducer, and c denotes the absence of 

 the id C. The Fi plant between the white ccRR and the yellow 

 CCrr has magenta pigment in the petal ; and the plants of F2 genera- 

 tion appear in the ratio 9 magentas : 3 yellows : 4 whites. 



4. The ids C, R, and D are sitiuated in the different chromo- 

 somes. 



Here I wish to express my hearty thanks to Professor K. Fujii, 

 under whose guidance this work has been carried out, and to 

 Professor J. Matsumura and Dr. T. Nakai for the facilities given 

 during the progress of this experiment. 



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