1908.] Flowers with Special Reference to Genetics. 53 



resulting colour is maroon, purple, or salmon-pink. Hence we find in 

 cultivated genera containing plastid pigments and anthocyanin a colour 

 series brown, crimson, or orange, purple, magenta, or salmon-pink, deep 

 yellow and pale yellow. 



Such is the case in Cheiranthus Cheiri, Chrysanthemum spp., Heli- 

 anthemum spp., Salpiglossis grandijlora, Tagetes signata, Tropceolum majus, and 

 Zinnia spp. 



This series differs from the anthocyanic-xantheic series in one respect;- in 

 the former the type is crimson and the purple or magenta is the derivative, 

 whereas in the latter the purple or magenta is the type, while crimson is 

 a derivative. These two contrasting series cannot be better exemplified than 

 by the two indigenous genera, Antirrhinum and Clieiranthus, and their 

 cultivated varieties. The wild Clieiranthus is deep yellow tinged with 

 brown ; cultivation has produced from the original, a pale yellow type, to 

 which the addition of anthocyanin gives purple. The wild Antirrhinum is. 

 magenta, which, on loss of some constituent, has given a yellow xantheic 

 type, and this gives, further, in presence of the reddening substance, a crimson. 



Stress should be laid, in connection with colour, on the conception of the 

 pigmentation of a plant as a whole. The power to produce colour is the 

 property of every cell of a pigmented plant ; frequently the flowers are 

 white or show but little colour in plants which are really pigmented, as, for 

 example, Solanum nigrum, Geranium Robcrtiamim, var. album. In a plant 

 having red, purple, or blue flowers, anthocyanin may invariably be detected 

 in the vegetative parts, such as cotyledons, under surfaces of leaves, wounded 

 or exposed areas, etc. The diffusion of colour throughout the plant is 

 manifested in the correlation so frequently found between fruit- and seed- 

 colour on the one hand and flower-colour on the other. De Vries (5) gives 

 as examples the green-flowered variety of Atropa Belladonna and the white- 

 flowered variety of Daphne Mezereum with yellow fruits ; also the white- 

 flowered Linum with yellow seeds as contrasted with the brown seeds of the 

 blue variety. The colour and pattern of seed-coat in Matthiola (Bateson and 

 Saunders (1) ) and Pisum (Lock (7) ) is also correlated with flower-colour in 

 the same way. 



Method for Examination of Pigments. 



The material to be examined is ground very finely with powdered glass in 

 a mortar, extracted with methylated spirit and filtered. If from the colour 

 of the residue, or from a microscopic examination, the presence of carotin be 

 suspected, a further extraction is made with benzine or chloroform. The 

 alcohol extract contains the pigments soluble in water and such plastid 



