a, onda 

“ye Tae ae oe 

IE EE OEE Ry Sere tn u u PNT NN ey eae 
VULGARIS L. AND IN PH. MULTIFLORUS WILLD. 101 
coloured (P) one, the proportions in Fa will vary from 2.4:1 to 
3:1, dependant on the presence of a few or more factors in both 
parents (Pa B x pAb for instance will segregate in F, in the pro- 
portion 45 coloured:19 white). White beans lacking the P-factor 
as also the other colourfactors, will show a segregation when 
crossed with coloured ones, between 1.3 coloured: 1 white and 
3 coloured: 1 white (e.g. PA X pa gives in F,9 coloured : 7 white 
plants). And finally the splitting after crossing of a white plant, 
possessing the P-factor but without the other ones, and a coloured 
bean, will show proportions between o:1 and 3:1; these pro- 
portions follow the scheme of polymeric factors 3:1, 15:1, 63:1 
and so on. 
2. The second character, studied first by TSCHERMAK and since 
by other writers also, is that of the marble-pattern. In the re- 
searches, relating to this character, an essential difference between 
two types of marbled patterns was discovered. In crossings be- 
tween beans with marbling as a constant racial character, and self- 
coloured plants, the marble-pattern is dominant, with a segregation 
of 3 marbled: 1 selfcoloured in the F 9-generation (TSCHERMAK 
58:20, EMERSON 331:124, TseBBES and Kooiman 69: 22, 130:51 
a. o.). But besides the action of this dominant racial character, 
marbling was found by TSCHERMAK in his first crosses already to 
appear in another genetic form: some crosses between selfcoloured 
and white plants gave as ,novum” a marbled F‚-generation and 
in these cases the segregation in Fo-families showed to be 1:1, 
for he found in these cultures 284 marbled: 263 selfcoloured, in 
F3-families 218 m:234 s and in Fy’s 91 m:93 s or as totals 593 
marbled plants: 590 selfcoloured ones. In his Fz and F;-cultures 
no one marbled individual gave a uniform posterity: all families 
descended from marbled Fo- and F3-plants segregated according - 
to the proportion 1:1. In crossings, giving whites besides coloured 
descendants, the proportions were 6 marbled: 6 selfcoloured: 4 
white plants. Moreover this eversporting marbling was observed 
in crosses between two selfcoloured individuals, as (TSCHERMAK 
1904, p. 34 of the separate) the uniform black race „Schwarzer 
Neger” crossed with the light yellowish brown „Hundert für Eine”. 
SHaw and Norton (1918, p. 71) have obtained in their crosses 
between Blue Pod Butter, with a yellowish brown seedcoat, and 
