SEED COAT COLOR IN GARDEN BEANS. 



85 



named color, G, is found in all black wax beans; the second, F, in Burpee 

 Stringless; and the third, C, in Giant Stringless and Golden Eyed Wax. 

 The color H is of a somewhat uncertain nature and our records are doubt- 

 less somewhat confused. It is probable that more than one character has 

 been recorded as H. There is reason to believe that additional determiners 

 of this series may exist, but our data are too fragmentary to afford a basis 

 for any positive assertions. In Table XIII. are shown the results of cross- 



Table XIII. — Crosses of Varieties carrying Yellow-hrown Determiners. 



ing several varieties carrying yellow-brown determiners. Golden Eyed 

 Wax X Giant Stringless yields only yellow beans like the parental vari- 

 eties. In cross 50, a yellow (C) by coffee brown (F), we get apparently a 

 simple monohybrid, the two varieties differing in that only Burpee String- 

 less possesses the determiner F. In all crosses involving Challenge Black 

 Wax the Fi seeds were black. In cross 81 Challenge Black Wax must 

 carry G and F, for coffee brown beans like those of Burpee Stringless were 

 extracted in F2 and later generations. It probably carries also the j^ellow 

 determiner C, for no beans lacking all three determiners appeared. In 

 the F2 generation the proportions should be 12:3:1, assuming that F is 

 epistatic to C and G epistatic to F. The proportions on record are 34:2:16. 

 There is reason to believe that some of the plants recorded as C were really 

 F. The progeny of one C plant were mostly F. Usually it is not difficult 

 to distinguish the two colors, but in this case it is probable that some errors 

 were made. In crosses 43 and 44 we probably have a monohybrid, the 

 Challenge Black Wax carrying the determiner G which is lacking in 

 Burpee Stringless. Both carry the F and C determiners. 



Following the notation used, the formulae for these varieties seem to 

 be as follows : — 



Golden Eyed Wax PtyZMm'OgfC 



Giant Stringless PTyZMm'OgfC 



Burpee Stringless, PTyZMm'OgFC 



Challenge Black Wax, PTyZMm'OGFC 



