ANTHOCYANINS AND GENETICS 155 



case of the occurrence of a red variety in roots is recorded by Wittmack 

 (495), that is the variety of the Carrot, Daucus Carota Boissieri 

 Schweinfurth, which has anthocyanin in the root, in addition to the 

 orange plastid pigment (carotin). 



As to variation in nature, that of albinism is most frequent. It is 

 found in the wild state among the British flora in Armeria vulgaris, 

 Calluna vulgaris, Campanula rotundifolia, Carduus nutans, C. palustris, 

 Digitalis purpurea, Erica cinerea, Lamium purpureum, Lychnis Flos- 

 cuculi, Ononis arvensis, Pedicularis sylvatica, Symphytum qfficinale 

 and Scilla nutans. Bentham & Hooker 1 also mention varieties of 

 Ajuga reptans, Campanula latifolia, Cenlranthus ruber, Delphinium Ajacis, 

 Iris foetidissima and Malva moschata without anthocyanin in the 

 flowers, but it cannot be deduced from the text in each of the above 

 cases whether there is complete absence of the pigment from the plant, 

 or loss from the flower only. As regards variation to redness, among 

 native species Poly gala vulgaris has a red-flowered variety. Bentham 

 & Hooker 2 record in addition red-flowered varieties of Delphinium 

 Ajacis, Veronica spicata, V. officinalis, V. Beccabunga and V. Chamaedrys. 

 Of species in which the flowers are normally white though they may 

 produce red varieties, or red pigmentation under certain conditions, 

 Gillot (457) gives a considerable list. Guinier (456) also notes a variety 

 of strawberry (Fragaria) with purple flowers, and Chabert (461) records 

 red flowers of certain species of Galium which are normally white- 

 flowered. A variation, extremely rare in nature, if not altogether 

 unknown, is that of white from a type with plastid yellow pigment, 

 though as a species differential character it is quite common, for 

 instance in the Ranunculaceae and Compositae. 







DETAILS OF CASES OF MENDELIAN INHERITANCE IN 

 COLOUR-VARIETIES. 



Many of the varieties mentioned in the last section have provided 

 material for cross-breeding work on Mendelian lines. Since most of 

 the species investigated differ more or less in their colour series and 

 behaviour, a separate account will be given of the more important 

 cases in turn. The genera and species which have been employed in 

 these investigations are the following: 



Cheiri ; the type is yellow tinged with anthocyanin : this varies to deep brown and this 

 again gives a yellow (the albino) free from anthocyanin. 



1 Handbook of the British Flora, London, 1896. 



2 Loc. cit. 



