1908.] 



Flowers with Special Reference to Genetics. 



55 



cyanin is absent, a xantheic pigment exists, which gives an orange colour 

 with acids and alkalis and an orange precipitate with basic lead acetate. 



The autumnal cultivated forms of Chrysanthemum resemble the above 

 species, except that the anthocyanin appears to be of the kind which does 

 not give a xantheic derivative. 



Coreopsis Drummondii has a brown patch of anthocyanin-containing cells 

 at the base of the ray-florets. The orange-yellow of the florets is due to 

 plastids containing carotin and xanthin. A xantheic pigment, probably left 

 as the anthocyanin retreats to the base of the florets, is also present in their 

 upper portions ; it turns orange-red with acids and alkalis and is pre- 

 cipitated by basic lead acetate as an orange precipitate. 



Dahlia variabilis shows the anthocyanic-xantheic series. The yellow turns 

 a brilliant orange colour, with acids and alkalis, and is precipitated as a 

 deep orange-red precipitate by basic lead acetate. The ivory gives the 

 yellow colour-reaction. Magentas and purples are anthocyanin on ivory, 

 and crimsons are anthocyanin with xanthein. 



Gaillardia spp. have usually orange-yellow ray-florets, with anthocyanin at 

 the base. The orange-yellow is due to plastids containing carotin and 

 xanthin. There appears to be no xantheic derivative. 



Gazania splcndens has orange-yellow ray-florets with a dark basal patch of 

 anthocyanin cells. Orange-yellow is again due to carotin and xanthin. 



Helianthus annuus has plastids containing xanthin ; a pale yellow variety 

 exists in which the plastids probably contain some derivative product of xanthin. 



Helichrysum bractcatum shows the anthocyanic-xantheic series. The white 

 variety gives the yellow colour-reaction with acids and alkalis. The yellow 

 contains a xantheic pigment, which gives an intense orange colour with 

 acids and alkalis, and a similarly coloured precipitate with basic lead 

 acetate. Magentas and crimsons are due to anthocyanin on white and yellow 

 respectively. 



Eieracium rubrum has anthocyanin in addition to plastids containing 

 carotin and xanthin. 



Picris pauciflorus, Senecio Jacobma, and Taraxacum officinale have only 

 plastids containing carotin and xanthin. 



Tagetes signata shows the anthocyanin-xanthein-plastid series. There is 

 an orange-yellow variety with plastids containing carotin and xanthin, arid 

 a lemon-yellow variety with plastids containing xanthin only ; both yellows 

 have in addition a xantheic pigment derived from anthocyanin ; it is 

 intensiiied in colour by acids and alkalis, and gives an orange precipitate 

 with basic lead acetate. Anthocyanin on the deep yellow gives brown ; on 

 the lemon-yellow maroon. 



