ANTHOCYANINS AND GENETICS 175 



Primula sinensis. The bulk of the work on this genus is due to 

 Gregory & Bateson. The following is a summary of the results which 

 have been published by Gregory (557). 



All colour in P sinensis is due to anthocyanin except the yellow 

 of the eye which is plastid pigment. 



Varieties of flower-colour. 



Albinos: The flowers contain no anthocyanin; they are differen- 

 tiated into dominant and recessive whites, but the flowers of both 

 look alike. 



Full colours: 



Salmon-pink. 



True red ' Orange King.' 



Blue reds Light (dilute) and deep shades of magenta and crimson. 

 Crimson is less blue than magenta but is more blue than 'Orange King.' 



Blues various shades. 



Pale colours : Shades of pink, of which ' Reading Pink ' is the deepest ; 

 of these apparently some correspond to magentas, and others to crimsons, 

 but the difference cannot be detected except by crossing. 



Distribution or pattern of colour. 



'Sirdar.' The pigment of the petals occurs in separate minute dots, 

 and the edges of the petals are white. The pigment itself may be either 

 magenta, crimson or blue. 



'Duchess.' The pigment occurs as a flush round the eye of the 

 corolla, and may be either magenta or crimson. 



Colour in the spot external to the eye. 



In certain varieties, there are spots of deep colour on the petals 

 just external to the eye. Deep spots are not fully developed unless 

 the stigma is coloured ; nor even if the stigma is coloured, are they 

 developed in plants which have no yellow (plastid) eye. Spots are 

 deeply coloured only in deeply coloured flowers; on light flowers 

 they are similar to those in the flowers with a green stigma. They 

 also depend on the base colour, since they are not visible in pale 

 coloured flowers, nor in flaked flowers unless the stripe occurs on the 

 area occupied by the spot. 



Colour in the ovary, style and stigma. 



By loss of an inhibiting factor, colour may be formed in these organs. 



