ANTHOCYANINS AND GENETICS 167 



to be dominant to the yellow, though the F x may vary in the amount 

 of anthocyanin it produces. The red variety is no doubt formed 

 owing to the loss of an inhibiting factor, and the F a plants would only 

 receive the inhibitor from one parent. When anthocyanin appears 

 in the primrose-coloured variety of Helianthus, the result is purple 

 and not chestnut red. 



Hordeum. BifEen (501) mentions that in Hordeum the paleae may 

 be white, black, brown or purple. The grain also may be white, bluish- 

 grey or purple. Apparently the purple colour is due to authocyanin. 

 According to BifEen, purple paleae as contrasted with white, and dark 

 grain with light grain, form pairs of Mendelian characters. 



Laihyrus odoratus. Bateson & Punnett (487, 496, 500, 516) have 



carried out extensive work on the colour inheritance in the Sweet Pea. 



The original wild type is probably most nearly represented by 



the variety now T known as 'Purple Invincible' with chocolate standard 



and bluish-purple wings. 



Loss of a diluting factor produces a variety with deeper wings, 

 ' Purple- winged Purple Invincible.' Loss of a full-colour factor gives 

 a tinged variety, 'Picotee.' 



When the blueing factor is absent, a series of red varieties appears 

 comparable to the above: 'Painted Lady/ with a deeper variety, 

 'Miss Hunt,' and a tinged variety, 'Tinged White.' 



It was shown early in the experiments with Sweet Peas that two 

 white varieties, indistinguishable except that one has long, the other 

 short pollen, gave a ' Purple Invincible ' hybrid, and from this result the 

 fact was deduced that colour production is dependent on two factors, 

 or that the two factors taking part in its formation can be inherited 

 independently. As in Matthiola, we must suppose that two factors 

 produce the most hypostatic colour, i.e. 'Tinged White,' and that 'Purple 

 Invincible ' resulted in the original cross because the white varieties 

 employed carried both B and a full-colour factor. 



These facts may be represented in tabular form as follows (De == full- 

 colour factor, Di == diluting factor) : 



CRBDeDi Purple Invincible. 



CRBDe Purple- winged P.I. 



CRBDi Picotee (see Bateson & Punnett, 498). 



ORB Picotee. 



CRDeDi Painted Lady. 



CRDe Miss Hunt. 



CRDi Tinged White. 



CR Tinged White. 



