FLORAL C()i,om<s AND PIGMENTS, 



175 



thoso ground colours the red pigment is soon lying in streaks of pure 



cannino, with white intorvalH where the yellow fails, but combined with 

 yollow to make a flery red, and with yellow intervals when that colour is 

 present." Hut, sinco the yellow pigment is always in the epidermal cells 

 when present, it can hardly ho said to form a ground colour to flic red so 

 that the latter lies on it. 



The yellow colour of the Dnhlin i* duo to a xantheic pigment in the 

 epidermal cells. Strong sulphuric acid and alkalis applied to the yellow 



petals produce a brilliant red colour. Hy appropriate treatment a yellow, 



waxy, amorphous substance may ho extracted from the Detail which 

 reacts with strong acids and alkalis as the petals do. 



The flowers of Loins corn irnhi ( ns also owe their yellow colour to a 

 dissolved pigment in their epidermal cells. This hceomes orange with 

 strong sulphuric acid and with alkalis. (!ourchet, who examined this 

 pigment, was unable to obtain it in crystals. The Mower almost always 

 contains anthocyan as woll. 



The Cudogyncs appear all to contain xantheic pigment, which varies 

 in colour from light primrose-yellow through orange to brown, and even 

 a dead black. The epidermal cells of the fringes in the throat of Ccelogytie 

 crista ta contain a yellow pigment in solution, together with a very few 

 solid particles of a yellow and others of a red colour, where the Mora 

 colour inclines to orange. The red particles are apparently carotin ; the 

 yellow particles are of the same nature as that dissolved in the (-(ill sup. 

 In the form C. crista ta Lcmonlaun the carotin is wanting to the colls. 

 In the form 0. niatata <tll><i all the pigment is absent. Strong sulphuric 

 acid turns the yellow tissue first an orange and then a red approaching 

 crimson ; alkalis turn it oranges. The pigment may be extracted with 

 alcohol, but no crystals can bo obtained from the solution. 



In Coslogyne ooellata the orange-brown markings on the flower arc 



due bo orange cell-sap in the epidermis, each coll of which contains also 

 an irregular lump of a bright-red granular substance. Strong sulphuric 

 acid turns the pigment a very deep red colour and dissolves the lumps of 

 pigment, which are composed of the same substance as that dissolved in 

 the sap. Potash gives the same colour reaction. 



The flowers of Coslogyne lonwnlasn have solid brown markings on the 

 lip nnd yollow fringes in the throat. Both are due to dissolved pigment, 

 and apparently the same pigment, for their reactions with strong sulphuric 

 acid are similar. The brown colour is due to a very concentrated solution. 



C&logyne Dayana has stripes and blotches of brown on the lahollum 

 of its flowers. The colour is due to cell -sap which is clear yellow in 

 weak solution. Sulphuric acid produces the flame colour reaction as with 

 the pigment of the other Codogynos. 



The palate of Ca&logync pandurala is of a dead black colour. The 

 pigment, which is present in enormous quantity, is yellow in thin layers, 

 There is every reason to believe that the xantheic pigments of all the 

 Cudogynos are identical. 



The petals of Rhinanthus Crisla-tjalli, which contain also yellow 

 chromoplastids, the yellow Hollyhock, the; yellow Carnation, and the yellow 

 Iceland Poppy an; all coloured by dissolved pigments which belong to 

 that subdivision which gives an orange or red colour with concentrated 



