M. Wheldalb 127 



10. From recent researches on the pigments of the Cornflower, 

 Willstatter states that the flower contains three pigments ; a purple 

 pigment which is an acid and owes its colour to the presence of a 

 quinone nucleus and which readily passes to a colourless isomer which 

 is a flavone derivative ; a blue pigment which is the potassium salt of 

 the purple ; and a red pigment which is an oxonium salt of the purple 

 with an organic acid. 



11. As a result of recent work, Combes has brought forward the 

 hypothesis that anthocyanin is not an oxidation product but, on the 

 contrary, a reduction product of the flavones. As evidence, he quotes 

 experiments which bring about the formation of anthocyanin from 

 flavones by means of sodium amalgam in acid solution and the forma- 

 tion of flavones from anthocyanin by treatment of the latter with 

 hydrogen peroxide. The evidence, however, cannot be considered con- 

 clusive in the absence of analyses of the products. 



12. A similar formation of artificial anthocyanin has been obtained 

 by Tswett, and by Keeble and Armstrong from plant extracts by treat- 

 ment with aldehyde and strong acid or nascent hydrogen in presence 

 of alcohol and strong acid. The artificial product has some of the 

 properties of natural anthocyanin but differs in its solubilities. Further 

 analyses are required for the determination of its identity. 



BIBLIOGRAPHY. 



1. Abderhalden, E. Biochemisches Handlexikon Berlin, 1911, Vol. vi. 



2. Atkins, W. R. G. "Oxydases and their Inhibitors in Plant Tissues." Sci. 



Proc. R. Soc, Dublin, 191.3, Vol. xiv. (N. S.), p. 144. 



3. . " Oxydases and their Inhibitors in Plant Tissues." Part 2. " The 



Flowers and Leaves of Iris." Sci. Proc. R. Soc, Dublin, 1914, Vol. xiv. 

 (N. S.), p. 157. 



4. Bach, A., und Chodat, R. " Untersuchungen iiber die Rolle der Peroxyde in 



der Chemie der lebenden Zelle." Ber. d. Chem. Ges., Berlin, various papers 

 in years 1902 — 4. 



5. Badr, E. "Einige Ergebnisse der experimentellen Vererbungslehre." Bei- 



kefte zur Med. Klinik, Berlin, 1908, Vol. x. p. 265. 



6. . " Vererbungs- und Bastardierungsversuche mit Antirrhiimm." Zs. 



indukt. Ahstamnnmgslehre, Berlin, 1910, Vol. ill. p. 34. 



7. Clabk, E. D. The Plant O.vidases. Dissertation, New York, 1910. 



9—3 



