Wakeman—Pigments of Flowering Plants. 
833 
molecules are V , 2', -3', 4', 5', 6', beginning with the carbon atom 
attached to the benzopyron group. 
Flavon group numbered according to 
O 
Richter 
O 
Kostanecki 
Though the chromon grouping occurs in the xanthon mole¬ 
cule, as has been shown above, this fact does not seem to be 
recognized in the outline of cyclic systems as given in Kichter’s 
Kohlenstoff-Verbindugen, for here an entirely different scheme 
of numbering is employed for the xanthon grouping. 
Xanthon group numbered according to 
O 
Richter 
O 
Kostanecki 
While it might appear more rational than either of these sys¬ 
tems to begin with some differentiated carbon atom and number 
each succeeding carbon atom in connection with which sub¬ 
stitution can take place 1, 2, 3,-,8, 9, 10, etc., without re¬ 
sorting to other symbols yet Kostanecki’s method undoubtedly 
53—S. A. L. 
