154 ANTHOCYANINS AND GENETICS 



of Primula sinensis (Gregory, 557). This variety has apparently the 

 power to form pigment in the flower but colour is prevented from 

 appearing by an inhibiting substance. Hence the case most closely 

 resembles the inhibited types of Anemone, Crataegus, Primula veris, etc., 

 mentioned above, and must, for the present, be included in this class. 



Up to this point we have been solely concerned with variation in 

 flower colour. But it should be borne in mind that the colour-varieties 

 already described may be characteristic of the fruit and seed and also 

 of the vegetative organs ; in fact, the whole plant may either be a total 

 albino, or pigment may be lost from various organs or parts indepen- 

 dently of each other. These phenomena will be dealt with later in 

 greater detail (see p. 180). A few instances of colour-variation in 

 different organs may however be mentioned. Of albinism in fruits 

 we have the white-fruited varieties of Atropa Belladonna, Daphne 

 Mezereum, Fragaria vesca, Ribes rubrum, Rubus Idaeus, Solanum nigrum, 

 Vitis vim/era and many others. De Vries (565) also notes a red-berried 

 variety of Empetrum nigrum. In seeds there are white-seeded varieties 

 of Pisum and Phaseolus. Of coloured roots also, white varieties may 

 occur as in Beta vulgaris. Variation to redness may also affect the 

 vegetative organs as for instance in the red-flowered varieties, rose 

 dore of Antirrhinum and ' Orange King ' of Primula sinensis, in which 

 the leaves, stems and petioles develop red anthocyanin instead of purple. 

 In the tubers, moreover, of the Potato, Solanum tuberosum (Salaman, 

 544), one may have both red and purple varieties (pigment due to 

 anthocyanin) as well as dominant and recessive white tubers. 



Loss of an inhibiting factor which in the case of the flower gives 

 a coloured from a white variety, is quite common in the vegetative 

 organs. This coloration of vegetative organs may be connected with 

 deepening of flower-colour, for example, deep varieties of Antirrhinum 

 and Primula sinensis which have pigment in leaves and petioles. Or 

 it may occur more obviously as a red-leaved variety, as in the following : 

 Atriplex hortensis, Berberis vulgaris, Beta vulgaris, Brassica oleracea, 

 Canna indica, Corylus Avellana, Fagus sylvatica, Lactuca sativa, Perilla 

 nankinensis, Plantago major; de Vries (498) also notes Tetragonia 

 expansa and the brown-leaved Trifolium 1 . Lastly a very interesting 



1 With regard to red-leaved varieties, de Vries (498, 565) notes that they may produce 

 green-leaved branches (red Corylus, Fagus, Betula). Also red bananas have produced 

 a green variety with yellow fruits. Whether this phenomenon is bud variation, or whether 

 it may be in some instances due to the production of the true albino and not the inhibited 

 type, is uncertain. An analogous example in flower-coloration would be Cheiranthus 



