522 WHITE— STUDIES OF INHERITANCE IN PISUM. 



Piebald Greens. 

 Telephone, Telegraph — Lock (54); Telephone — Tschermak ; 

 Telephone, William I, American Wonder, Laxton's Alpha — Bate- 

 son (i) ; Telephone — White (98). 



Results from Crossing. 

 Yellow X yellow always gives yellow in Fj and succeeding 

 generations, except in crosses with the light yellow cotyledon va- 

 riety Goldkonig in which case a certain proportion of green coty- 

 ledon seeds are obtained in F^, yellow being dominant in F^. The 

 ratio of yellows to greens in such crosses either approximates 3 : i 

 or 13:3. The actual results (98) obtained from crosses of Gold- 

 konig with four or five other yellows in F^ were : 



457 distinctly yellow : 23 yellowish green : 86 green. 



Considering the last two groups together, the proportions are 457 

 yellow: 109 green or a ratio of 13:3, the theoretically expected 

 being 459.2 yellow : 106.2 green. These peas were reclassified after 

 mixing several times with the same result. No F. results have been 

 obtained as yet. 



Orange yellozv X light yellow gives dominance in F^ of the for- 

 mer (90). 



Yellozv X green gives all yellow in Fj in all cases except where 

 the variety Goldkonig is used. Where Goldkonig is used as a yel- 

 low, all F/s are green. White (98) has tested out five different 

 varieties with green cotyledons and always secured F^ seeds of 'a 

 distinct green color. Several cases of dominance of green were 

 obtained by Lock (54), Tschermak and Bateson (i), but they are 

 mostly explained by these experimenters themselves as either errors 

 in labeling or in improper maturing. Repetitions of such crosses, 

 using the same varieties, did not give these exceptional results. 



In F2, excluding Goldkonig from consideration, yellow X green 

 gives yellows and greens again in the proportion 3 yellows : i green. 

 In F,, all the greens breed true and give only green progeny. Of 

 the yellows only about one third breed true to yellow, the other two 

 thirds giving rise again to yellows and greens in the proportion of 

 3:1. The true breeding yellows and greens are believed to continue 



