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THE AMERICAN NATURALIST. [Vol. XXXVII. 



this to be the case in the Violacere and in Gentiana and in 

 Myosotis versicolor. The sequence of the floral colors has been 



Two Color Erics'. — The colors of flowers may be divided into 



low, and a derivative series composed of red, purple and blue. 

 In the first the pigments are insoluble and are contained in 

 plastids or are absent. In the second they are dissolved in the 

 cell sap. Of the 4020 northern angiosperms 3001 belong to the 

 first series, while 1019 belong to the second. Of the 2972 

 entomophilous species 1968 belong to the first and 1004 to the 

 second series. The flowers of the second series are far more 

 numerous in the Polypetalae and (iamopetake than in the Mon- 

 ocotyledones and Apetalae. The pigments of the first series are 

 most common in primitive families, where the flowers are rotate 

 and but little modified. Very many flowers of the second series 

 have the petals green, whitish, or yellowish in the bud or at the 

 base. In the color changes which takes place in individual 

 flowers green may be succeeded by every color, and red and blue 

 frequently pass through a white or yellow stage. In individual 

 flowers the tendency of green, white, and yellow to change to 

 red and blue is much stronger than the reverse. 



