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M. WHELDALE. The colors and pigments of flowers with spe- 

 cial reference to genetics. - - (Proc. Roy. Soc., Ser. B, 81, 

 1909, No. 3545, pp. 44-60; Abs: E. S. R., XXI, Aug. 1909). 



A series of investigations on the color of flowers has been 

 undertaken with a view to the interpretation of the phenomena in 

 the inheritance of flower color. The author makes an attempt to 

 classify roughly the pigments found in flowering plants and at the 

 same time to determine whether there is any connection between 

 the genetic behavior of the pigments and their chemical reactions. 

 He classifies the pigments into those in solution in the cell sap 

 and those associated with specialized protoplasmic bodies, the chro- 

 moplasts. The first group includes the soluble red, purple, and 

 blue pigments known as anthocyanin and the soluble yellow pig- 

 ments called xanthein. The second group, which is insoluble in 

 water, includes carotin, xanthin, etc. 



About two dozen natural orders of plants were examined, and 

 summarizing his results, the author states that anthocyanin includes 

 several pigments differing as regards their inheritance, the colors 

 to which they give rise in variation, and their behavior toward 

 chemical reagents. The colors of the varieties arising from the 

 anthocyanic type may be regarded as components of the original 

 anthocyanin, and the type may be supposed to lose its components 

 in succession, thus giving rise to color variations. 



Broadly speaking, the author states that there are two series of 

 color variations, one containing a xantheic derivative and the other 

 without any such derivative. Albinism in the first series is due to 

 a lack of anthocyanin and xanthein ; in the second series to a de- 

 ficiency in anthocyanin only. Xanthein includes several different 

 yellow pigments. 



So far as the investigations have proceeded, there appears to 

 be a correlation in genetics between the behavior of pigments and 

 their relation toward chemical reagents. 



In the case of plastid pigments, the type may contain carotin, 

 xanthin, or both, and varieties arise in some cases from loss of 

 power to produce carotin, or in others from loss of some of the 

 constituents of xanthin. Anthocyanin may exist together with plastid 

 pigments, in which case derivative products of both forms of pig- 

 mentation are found among the varieties. 



