2 
I. N AG AI : 
3. An Interpretation of the Results. 
4. Discussion. 
ID'. Summary and Conclusion. 
Explanation of the Plate. 
Postscript. 
Introduction. 
The workers in genetics have established the fact that in certain cases 
the formation of anthocyanin pigments is caused by the interaction of a number 
of definite pigment yielding components which are retained by the separate 
genetic factors. Neither of these components has the power to produce the 
pigment unless the complete system is established by their union. We owe 
much to the labours of Bateson, Punnett, Miss Saunders, Miss Wheldale, 
Bam- and many others on the part of genetics, 1 and Willstätter and his 
collaborators in the field of chemistry who have shown for the first time, the 
exact chemical constitution and the interrelationship of the colouring matters 2 
concerned. 
The present paper deals with the result of an investigation carried out 
in order to discover what relation exists between anthocyanin and brown 
pigments both of which occur widely in the plant kingdom and what obser¬ 
vation can be made with regard to the physiological action of the genes which 
are analysed by the breeding experiments for the characters in which those 
pigments are concerned. 
I. Physiological Study. 
1. The Action oe Oxidizing Enzymes on Anthocyanins. 
If we accept the view that anthocyanins are formed by the oxidation of 
flavone instead of by reduction, and the oxidizing enzymes play an essential 
pari in this change in the living plant cells, it is necessary to offer the direct 
evidence to lend support to the view. 
When an alcoholic or aqueous extract of anthocyanin which is slightly 
1. See Wheldale, M., Anthocyanin Pigments of Plants. 1916. 
2. See Perkin, G. A., and Everest, A. E., The Natural Organic Colouring Matters. 1918. 
