1908.] 



Flowers with Special Reference to Genetics. 



57 



Zoasacece. 



Bartonia aurea has plastids containing carotin and xanthin. 



Malvacece. 



Althcea rosea shows the anthocyanic-xantheic series. The yellow pigment 

 is intensified in colour by acids and alkalis and is precipitated by basic 

 lead acetate as a brownish-orange precipitate. The ivory gives the yellow 

 colour-reaction. It has not yet been ascertained whether the yellow is 

 recessive to ivory nor whether an albino exists. Anthocyanin gives various 

 purples, mauves, magentas, pinks, crimsons, and orange, according as it is 

 present on an ivory or on a yellow ground. 



Nyctaginacew. 



Mirabilis Jalapa shows the anthocyanic-xantheic series. The yellow 

 pigment becomes paler with acids and alkalis, and is not precipitated by 

 lead acetate. The white variety gives the yellow colour-reaction, but is 

 recessive to yellow. The red pigment, as already stated, differs from most 

 other forms of anthocyanin. 



Onagracece. 



(Enothera Lamarchiana has plastids containing xanthin and, in addition, 

 a pale yellow xantheic pigment intensified to orange-yellow by acids and 

 alkalis. 



Papaveracece. 



Argemone grandijlora exists in three varieties, deep and pale yellow and 

 white. The deep yellow is due to plastids containing carotin and xanthin ; 

 in addition, a crystalline glucoside, similar to that in Eschscholtzia, is present 

 in the sap. The pale yellow appears to contain xanthin and the glucoside, 

 and the white gives the yellow colour-reaction. 



Eschscholtzia californica has plastids containing both carotin and xanthin ; 

 sometimes the margin or outer half of the petals is yellow or the orange 

 petal is striped with yellow. Examined microscopically the yellow colour 

 of the streaks and margin is seen to be due to yellow plastids, containing, 

 undoubtedly, xanthin only. The orange portions contain orange plastids, 

 carotin being present in addition in these. The sap contains a glucoside 

 (the soluble yellow pigment of Courchet (3) ), crystallising in spherules of 

 needles. E. Caniculaia rosea is cream tinged with pink. Plastids are 

 present containing only a little xanthin ; most of the plastid pigment 

 appears to be similar to that in cream Matthiola. The glucoside is also 



