During the past few years the pigments occurring in a number of cultivated American grapes have been investigated in this Laboratory. It has been found that the anthocyans isolated from dark blue grapes such as Concord, Z Xorton and Cliaton, representing Vitis labrusca, V. aestivalis and V. riparia consist principally of monoglucosides of monomethyl delphinidin. The pigment occurring in Seibel grapesI4 a hybrid of Vitis aestivalis, V. rupestris with 17. ...
