246 PLANT-BREEDING 



which grows in many forests of Germany. It has brownish 

 flowers and large and shiny black fruit, the color consist- 

 ing of two factors, a yellow and a red one. A variety of this 

 species was discovered by Schiitz in a wood in the neighbor- 

 hood of Calw in Wiirtemberg about the middle of the last 

 century (1851; cf. Hoffman, Sp. et Var., p. 87). It has pale 

 greenish flowers and bright yellow berries. It comes true 

 to its character from seed, and is often cultivated in botani- 

 cal gardens. The red dye or anthocyanin, which darkens 

 the corollas of the species and is concentrated in the fruit 

 to a degree that makes it black, is absent in both organs 

 in the variety, the yellow not being affected by the change. 

 Evidently the red dye is the same color in both organs, 

 and as soon as it became latent by the production of the new 

 form, it disappeared simultaneously from the flowers and 

 from the fruits. 



In many species this anthocyanin is not limited to the 

 flowers and the fruits, but may be displayed in the foliage 

 also. The stem and the branches, the leaves and their 

 stalks, and even the bracts of buds and the coats of a bulb 

 may be imbued with the color. It very often happens in 

 such cases that the white or pale varieties show their marks 

 in the correlated organs. As the first example, I choose the 

 thorn-apples. They are known in a white and in a blue 

 variety, the flowers of the latter being of a pale blue. The 

 colored form (Datura Tatula) has stems and leaves of a 

 brownish color, but the same organs are of a pure green in 

 the white- flowering plants (D. Stramonium). Even the 

 young seedlings may be distinguished by the tinge of color on 

 their stem, and whenever the dark ones are separated from 

 the pale, all of the first will bear blue flowers and all of the 

 latter white. 



It would be easy to give a list of such examples, especially 

 of garden plants, since horticulturists often select their seed- 



