Miss Wheldale, On the nature of anthocyanin. 161 



6. Hence we may state that successive oxidation stages of 

 an aromatic chromogen probably give rise to the colour series, 

 pink, purplish-red, and purple of the more commonly occuiTing 

 form of 'anthocyanin.' 



7. An albino results either from the loss of the fundamental 

 chromogen or from the loss of the reddening enzyme from the 

 plant. The blueing enzymes depend for their manifestation on 

 the presence of both the first two factors. 



8. In Antirrhinum and Phlox the albino carrying G, the 

 chromogen, is ivory-white in colour and is distinguishable from 

 the dead-white albino carrying R, the enzyme, not only chemically 

 but also in appearance. In Lathyrus and Matthiola no difference 

 in appearance can be detected between the albino carrying C and 

 the albino carrying R ; in the two latter genera a thorough chemical 

 examination of the albinos has yet to be made. 



9. The less commonly occurring scarlet 'anthocyanin' usually 

 gives no iron reaction; hence the difference in colour is probably 

 connected with a difference in constitution. 



10. The later oxidation stages producing purple 'anthocyanin ' 

 are frequently accompanied b}'^ a change from an iron-greening to 

 an iron-blueing reaction. It is doubtful whether this is due to 

 total oxidation and disappearance of the iron-greening chromogen 

 or to a specific reaction of the 'anthocyanin' itself with iron salts. 



BIBLIOGEAPHY. 



1. CuRTEL, G. "Recherches physiologiques sur la fleur." Ann. des 



Sci. naturelles, Serie viii., T. vi. 



2. Dennert, E. "Anatomie und Chemie des Blumenblatts." Bot. 



Cenfralb., 1889. 



3. Gautier, a. " Sur la coloration rouge eventuelle de certaines 



feuilles et sur la couleur des feuilles d'automne." Compt. Rend. 

 Acad, des Sciences. Paris. T. CXLIII., 1906. 



4. IcHiMURA, T. "On the Formation of Anthocyanin in the Petaloid 



Calyx of the Eed Japanese Hortense." Jour. Coll. of Sc. hnp. 

 Univ. Tokyo, Vol.. xviii., 1903. 



5. MiRANDE, M. "Sur un cas de formation d'anthocyanine sous 



rinfluence d'une morsure d'insecte." Compt. Rend. Acad, des 

 Sciences. Paris. T. cxLiii., 1906. 



"Sur I'origine de ranthocyanine deduite de robservation de 

 quelques insectes parasites des feuilles." Compt. Rend. Acad, 

 des Sciences. Paris. T. CXLV., 1907. 



