A tiENETICO-PHYSIOLOGICAL STITDY OX THE FOIiMATION KTC. 61 



\\;is the dorivatix'C of !ii)iji;eniu jukI rose dove Jiml luiirjeuta from lutoi>liii. Tui' 

 factors are uecessan- to convert the cliroiuogeii duteolin) to mageuta but oulj- 

 one is essentiiil to rose dore. Thus 



UyiiRRl^i 7JIIÜRHU11 White 



YYIIrrU} Ivorj- (apigeuiu) 



YYitriib Yellow (luteoliu) 



YyilRM Orange 



YijiiRrliJ) Crimson 



YijIiRrhl) Kose dore 



YijRRrUn Magenta 



in wliicli / is a dominant ivov}' factor, inliibiting the formation of luteolin. Y 

 is the factor for yellow whicli is due to apigeuiu, R and B are the fsictors 

 vhicli convert the chromc^n to anthocjaniu. 



The case of Liiiaria maroccana, studied by CORREXS (1912)' was as 

 foUo^vs : Ked is dominant over white, and purple over red. At presant his 

 inteq^retation of the above ease is hardly to Ije maintained. He dwelt upon 

 the fact tluit authocyauin is red in acid aud blue in alkali aud tried to inter- 

 pret the factor dillerence of purple and red by that of acidity- in the ceU sap. 

 But such seems to be unlike the usual case. H;VAS (1916)' found that the 

 cell sap containing blue anthocyauin is acid or neutral but rarely alkaline if 

 acidity is determined by the hydrogen gas chain. 



WlLLSTATTER attempted to explain the variation in the colora* of cyanidin 

 from red to blue In- the quinonoid sti'uctxu-e of the molecule. The phelolic 

 character of the benzene i-ing allows the formation of salt with alkali, the red 

 is the acid salt (oxonium salt) the blue is the jOTtassium or metallic salt 

 (alkali pheuoLite) aud the violet is the anhydride of the pigment. But his 

 hypothesis hardly explanis how the deep lilue anthocyauin can exist in the 

 cell sap of the pLant which is acid in reaction and further that an addition 

 of alkali destroys the blue anthocyauin rather than deepening the colour. 



A new explanation of the causes of variation in the colour of flower's has 

 been put forward by K. Shibata, Y. Shib-^ta, aud I. K-AShiwagi (1919)' based 



1. CoiuiEKs, C, Die Neue Vererbungsgesetze. 1912. 



2. Haas, A. E., The AciiUty of Plant Cells .is shown by X.ntur.nl InJic.itors. Jour. Biol. 

 Chcm. 27 : 233, 1916. 



3. Shibata, K., Shtbata, Y., .-»nil Kashiwaci, I.. Loc. cit. 



