No. 523] 



INHERITANCE IN POTATOES 



427 



purple tinge could be detected. Even this color, how- 

 ever, may be of the same nature as the purple color, the 

 difference being in the completeness of the reaction 

 forming the blue dye. It will be remembered that lit- 

 mus reacts in this manner. Several cross-pollinated 

 and several self-pollinated fruits were obtained from 

 this variety, but none of the seedlings had flowered in 

 1909, the second year of their growth. 



The seedlings of the potato are very slow to flower in 

 a New England environment, and but few flower records 

 were obtained among several hundred plants. One 

 selfed variety with purple flowers gave progeny all with 

 colored flowers. Three selfed varieties with purple 

 flowers gave both purple and white flowers: the total 

 number of seedlings that flowered was nineteen, of which 

 fourteen were purple-flowered and five were white-flow- 

 ered. Three selfed white-flowered varieties gave noth- 

 ing but white-flowered progeny. 



Since three white-flowered varieties gave nothing but 

 white flowers and three out of four colored varieties 

 showed a hybrid condition with segregation of color, t 

 purple is probably dominant to its absence. Color a~ 

 no color is probably a single Mendelian pair, but t" 

 can not be stated with certainty from such meager dat' 



Potato tubers, when colored, 2 are either purple or red. 

 In both cases the color may extend over the entire tuber 

 or may be limited in extent. No definite mosaic pattern 

 is formed when the color is limited, but the splashes of 

 color are restricted to pretty definite areas. It is prob- 

 ably due to a separate Mendelian factor, for the mosaic 

 varieties and the self-colored varieties are distinct. 

 Tuber color varies quantitatively more than flower color. 



