Heredity 187 



tribution of the cells containing the colored cell-sap, 

 and also to the combinations of dissolved coloring 

 matter with the yellow, orange, and red chromoplasts 

 and the green chloroplasts. There is occasionally found 

 in the cell-sap a yellow coloring matter known as xan- 

 thein ; it is nearly related to xanthophyll, but soluble in 

 water. 



Thus we see the plant colors are not always unit-charac- 

 ters, such as hairiness, glabrousness, and the like. Certain 

 colors found in plants, purple flowers, for example, are 

 the result of the union of certain other pigments. These 

 pigments are produced by definite units in the gametes. 

 Color inheritance thus becomes very complicated as the 

 results of certain crossings indicate. 



White flowers in F 2 from red X cream. Bateson points 

 out a typical case of the paradoxical appearance of white- 

 flowered individuals in the F 2 from the cross of a sap- 

 colored variety with a variety having cream-colored 

 flowers. For example, in sweet peas or stocks, when a 

 red-flowered type is crossed with a cream, FI is red with- 

 out any cream color. F 2 consists of 9 without cream, 3 

 reds with cream, 3 whites, 1 cream. 



The red-flowered variety consists of red sap color only 

 and the cream variety of yellow plastids only. These 

 are inherited separately in the hybrids. The 9 reds of 

 the Ft hybrids have a much brighter red color than the 

 red-creams. In the latter the red is diluted by the yellow 

 plastids. 



When the allelomorphs are correctly distinguished, the 

 significance of this series is obvious. The operations may 

 be shown in tabular form, thus : 



