78 I. NAGAI: 



and othei-s' have reporbed, the reaction place saems to be chiefly located in 

 the cytoplasm. All the genes must be retained in the nuclear substance of the 

 spjrophytic cell in some latent state, and the reaction done by them iu the 

 cell to produce the pigment must be realized by some sort of substances deiived 

 fi'om the nucleus. The actual relation between the substance of genes in the 

 nucleus and the mechanism iu the cytoplasm conditioned by the former, is 

 known to none of us. It seems therefore altogether premature to speculate, 

 as certain biologists might propose, that the gene itself is the enzyme. Even 

 in the pure chemical field, we do not know as yet the exact chemical nature 

 and the mode of action of enzymes. 



Ill Summary and Conclusion. 



In a number of species of plants examined, two groups of pigments 

 anthocyanins and the reddish brown pigments (phlobaphenes) can be traced 

 to the chromogenic substances, previous to their formation. In certain cases, 

 both of the pigments can be formed from the same chromogenic substance by 

 the action of various complementary pigment-yielding agencies. ^ 



The chi'omogenic substances can be identified to two gi-oups of aUied sub- 

 stances, one of which is designated as the chromogenic substance F which 

 includes the glucoside of certain flavones and flavonols, and the other, the 

 chi'omogenic substance P of which the chemical nature is yet unknown. 



Evidence is given to show that certain brown and reddish bro-\vTi pigments 

 (phlobaphenes) are the oxidation products of the chi-omogenic substance P and 

 F. 



Certain anthocyanins are completely decolorized by the action of oxidizing 

 enzymes. 



Certain flavones, flavonols and their glucosides yield a chai"acteiisti(! oxida- 

 tion colom- by the action of oxidizing enjymes. 



1. Gtjtlliekmont, .\., SvTr la formation de r.mthocyime an siin ilcs mitochondries. Comp. 

 Kcnil. Acad. Sei. Paris. 156 : 1921. 1913. — GriijUEBMONr), ^oiivelles rechercbes oyfologiqnes siir In 

 formation des iiigments anthocyaniques. Ibid, 157:11)00, 1913.— GriLiiERMOND, Quelques obser- 

 vations cytologiques sur la mode de formation des pigments antbocyaniques dans les fleurs. 



Ibid. 101 : 494, 1915 Guilijekmond, Hecberches cytologiques sur la formation des pigments 



antbocyaniques. Kev. Gene. Bot. France. 25:295, 1914. — MonE.U"x, F., Loc. cit.— Mira.sde, M., 

 Observation sur le %'iTnnt de la formation lytologique de 1' anthocyanine. Comp, llend. .\cad. Sei. 

 Paris. 103:368, 1910. 



