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



as the chromogen for the 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 ; arid 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. Fujn, 

 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. 



Literature cited 



Bateson, W. (1909) Mendel's principles of heredity. Cambridge. 



Baur, E. (1914) Einfiihrung in die experimentelle Vererbungslehre. 



Everest, A. E. (1915) Recent chemical investigations of the anthocyan pigments 



and their bearing upon the production of these pigments in plants. Journ. 



Genetics, vol. 4, p. 361. 

 Ikeno, S. (1918) Zikken-idengaku. Tokyo. 



Leake, H. M. (1911) Studies in Indian Cotton. Journ. Genetics. 1, p. 205. 

 Miyake, K., Imai, Y. (1920) Genetical experiments with Morning Glories. I 



(Japanese) The Bot. Mag. Tokyo, vol. 34, pp. 1-26. 

 Marryat, D. C. E. (1908) Hybridization experiments with Mirabilis Jalapa. 



Eep. Evolut. Commit, p. 32. 

 Saunders, E. R. (1910) Studies in the inheritance of " doubleness " in flowers. 



I. Petunia. Journ. Genetics. 1, p. 57. 



Saunders, E. R. (1911) Further experiments on the inheritance of "doubleness" 



and other characters in Stocks. Journ. Genetics. 1, p. 303. 

 Saunders, E. R. (1917) Studies in the inheritance of "doubleness" in flowers. 



II. Meconopsis, Althaea, and Dianthus. Journ. Genetics. 4, p. 165. 

 Shibata, K. (1915) Untersuchungen iiber das Vorkommen und die physiologische 



Bedeutung der Flavonderivate in den Pflanzen. I. Mitteilung. Bot. Mag. 

 Tokyo, vol. 29, No. 343. p. 118. 

 Shull, G. H. (1917) The significance of latent characters. Science. N. S. 25, p. 

 792. 



