In the previous communications of this series we have recorded the results of observations on the oxydases and chromogens concerned with the production of anthocyan pigments. The study of pigment formation is continued in the present communication, the sections of which deal with the following subjects :— 1. A pigment-producing glucoside of the wallflower (
Cheiranthus Cheiri
). 2. The formation of pigment-producing substances from glucosides. 3. The biochemistry of Mendelian colour characters Section 1.—
A Pigment-producing Glucoside of the Wallflower.
It is customary to divide the sap-pigments of plants into two series, the red, purple, and blue anthocyan pigments, and the yellow xanthein pigments. Miss Wheldale has, however, suggested, on genetical grounds, that the anthocyan and xantheiu pigments are related with one another. This author points out that most plants contain colourless or pale yellow substances which give a canary yellow colour with ammonia. When heated with dilute acid they assume a deep yellow colour and reduce Fehling’s solution. Hence, they are to be regarded as glucosides.
Cryptic self-incompatibility in the wallflower: Cheiranthus cheiri L.
