The Formation of the Anthocyan Pigments of Plants. 131 



II. Sap Pigments — 



a. Yellow. Hydroxyflavone glucosides or derivatives 



thereof contain C, H, 



h. Ped, e.g., of wallflower (see p. 117). Products of the 

 action of oxydase on hydroxyflavone glucoside 



derivatives contain C, H, 



[Whether all anthocyan pigments are of this type is 

 unknown.] 



c. Ped and brown, e.g., of plum. Substances produced 



by the oxidation of phenols in the presence of 

 ammo-acids contain C, H, 0, N 



d. As suggested in Section 3, tbe so-called anthocyan 



pigments (red and magenta) of flowers may arise 

 as the result of the oxidation of phenol brought 

 about by an organic oxygen carrier ; contain C, H, 



4. The benzidine-methylquinol-oxydase reaction (p. 128) provides an 

 analogy with the lie/ type of pigment formation, and suggests the hypothesis 

 that the higher members of a flower colour series (see p. 129) owe their origin 

 to the presence with the lower members of specific substances which, acting 

 as receivers of oxygen, reduce the pigments characteristic of the lower 

 members of the colour series, accept oxygen, therefrom, and thereby become 

 oxidised to pigments of specific colour. 



