560 WHITE— STUDIES OF INHERITANCE IN PISUM. 



static to Lf. The absence of Lf is epistatic to the absence of Ef, and 

 determines the time of flowering of the early parent, while the 

 absence of Ef causes the early variety to bloom a few days later. 

 Gametic contamination of some sort is believed to be involved, but 

 the factors are distinctly stated not to be " inconstant " in the sense 

 in which Castle (lo) uses the term. Lf ("A") is partially coupled 

 with factor A for flower color, the proportion of non-cross-over to 

 cross-over gametes approximating 7:1. 



II. Number Flowers per Single Peduncle. 



Flowers in Pisum are borne either singly, in twos or in threes on 

 a single axillary peduncle, unless the factor for normal stem is 

 absent. P. elatius is an excellent example of the " flowers per 

 peduncle 2-3 " type, while most of the commonly cultivated varie- 

 ties are two-flowered or 1-2-flowered. Such early forms as Veloc- 

 ity, First of All, and Black Abyssinian are almost totally single 

 flowered. 



According to Hurst (44), the tendency to bear pods (and con- 

 sequently flowers) in pairs is inherited. Vilmorin (90) states 

 I -flowered and 1-2-flowered peduncles to be dominant to 2-3-flow- 

 ered peduncles, these two characters being determined by the pres- 

 ence and absence of a single factor. In the table, this is designated 

 Fn. Strictly one-flowered types and their relation to the 1-2-flow- 

 ered type apparently have not been studied. 



12. Foliage and Stem Color. 



The foliage and stem color of peas is either green or yellowish 

 green, each color generally being associated with unripe pods of the 

 same color, although a few purple and yellow podded varieties of 

 peas are known with green leaves. Green or purple podded yellow- 

 leaved varieties are unknown. Gold von Blocksberg and Goldkonig 

 are typical yellow-leaved varieties. 



The writer obtained from crossing yellow foliage, etc., X green 

 foliage, etc., green foliage, green podded F^ progeny, which in Fo 

 gave 681 with green foliage, green pods and 222 with yellow foliage, 

 yellow pods, the expectation being 677:226. Of 45 green foliage, 



