IT I 



.JOURNAL OF Till-: ROYAL HORTICULTURAL SOCIETY. 



frequent presence of other, often colourless, substances which also react 

 with strong acids, and with alkalis. 



Only two, so fur as I know, havo been isolated, and these because they 

 are easily orystallisable. As they are typical in their reactions of the two 

 subdivisions I have mentioned, I give an account of them here. Courchet 

 obtained, by the action of strong alcohol on the flowers of Linaria vulgaris, 

 a golden-yellow solution which on concentration deposited deep-red needle 

 crystals grouped in spherules. They dissolved in strong sulphuric acid, 

 forming a blood-red solution, and in strong solution of potash to a pale 

 yellow solution. Sulphuric acid on the floral segments gives the same 

 red colour, and on the palate of the flower, where the yellow colour 

 is very intonso, this reagent gives a red so deep as to appear nearly 

 black. 



The same observer also obtained in very small quantity from the 

 flowers of blschscholtz-Ut califomica a pigment which crystallises in yellow 

 needles grouped in spherules, and which dissolves in strong sulphuric acid 

 to a clear yellow solution. I find this samo pigment in very large quantity 

 in (lowers of N&fcissilS Tazetta, 4 Grand Soleil d'Or.' If these flowers are 

 exhausted with strong alcohol and tho solution set to ovaporate spon- 

 taneously, there first separate out rod crystals of carotin, then oily drops 

 of xanthin, and finally tho yellow needle-crystals of tho pigment in ques- 

 tion, and to a very large amount. Thoso crystals may be easily separated 

 from the xantheic pigments by the action of ether, which dissolves the 

 latter, but has no effect on the former. They are slightly soluble in cold 

 water, easily in hot water, and by means of tho lattor, therefore, they may 

 be purified. Their solution gives a greenish colour with ferric chloride, 

 indicating a tannin character, and a yellow precipitate with basic lead 

 acetate, and tho substance does not reduce Fohling's solution on boiling. 

 On long boiling, however, with dilute sulphuric acid, the substance is 

 hydrolysed with the production of a reducing sugar and a red crystalline 

 Compound insoluble in cold water. Tho pigment is, therefore, a glucosido. 

 It is worthy of note that thero are varieties of this very variable Narcissus 

 which contain tho throe pigments named, others with two, others with 

 ono, and the variety called ' Papor-white ' contains none of them. 



Of the flowers which owe their colours to xantheic pigments the fol- 

 lowing may be notod. In all of them the pigment is contained in the 

 epidermal cells of one or both surfaces of tho floral segments. In this 

 respect, therefore, it is like anthocyan. 



The cultivated varieties of Antirrhinum. Tho pigment which gives 

 the (loop yellow colour to tho palate of this flower, even in otherwise white 

 varieties, is of tho same kind, although in groater concentration, as that 

 which colours the potals generally in the yellow form, or which forms 

 tho yellow stripes in some forms. Strong sulphuric acid, as well as 

 alkalis, convert tho yellow to a deep orange or orange-red colour. In 

 some varieties there is a peculiar brick-rod colour which is almost cer- 

 tainly duo to an admixturo of anthocyan and the xantheic pigment in the 

 same cell. Do Vries,* speaking of striped Antirrhinums, says: — "In 

 some tho ground colour of tho flowers is yellow, in others it is white. On 



* IV Yiics. 8p$0i$8 and Varieties: Their Oritjin bij Mutation, OhioagO, 1905, 

 p. BIS. 



