Xo. 639] INHERITANCE IN NICOTIAN A TABACUM 329 



color of his Giant Bed-flowering tobacco is dominant to 

 pink in a simple mono-hybrid relation, Fj being carmine 

 and F2 3 carmine : 1 pink. He also crossed this carmine- 

 flowering variety with a white-flowering form and ob- 

 tained light carmine in Fj and a distribution which might 

 be taken to conform to the ratio 9 carmine : 3 pink : 4 white. 

 We took these results to indicate that his eaniiiiic. which 

 must be very similar to our red, was ncvci tliclcss uvnet- 

 ically distinct from it. This belicl' was somewhat 

 strengthened by the fact that our red does not fall upon 

 the carmine of the Eidgway* color scale, but lies slightly 

 removed from it between rose red and pomogranatf 

 purple, although a' difference of this kind might conceiv- 

 ably be due to the effect of differences in the residual 

 genotype. We have, however, a variety, f)iirj/nrr<f { V. C. 

 B. G. 25/06), which exhibits a red flowci- eoloi- somewhat 

 darker and more intense than that of jjuicropJii/Ua, and 

 wdiich some preliminary crosses indicated was dominant 

 to pink and white. We accordingly suggested the follow- 

 ing factor formulas for these four colors : 

 WWREPP = carmine 

 TrTF/^/?pi^ = light pink 

 WWrrpp = red 

 7r/r///i';)/> = white 

 In this formulation ll'ir// ///'/', vv\n-r<vnx> tlie 1)a-ie type, 

 carmine in color; ir. the ( 11 ffe fence from it whirh uives 

 white, irrespective of whieh members of the pairs oecnpy 

 the R OT P loci; />. that whieh gives pink: an<l that 

 which changes pink to red. ((hvionsly wliite-tlowering 

 varieties may be of four diffei-ent uein>t \iie<, viz., 

 inrPRPP, H-u-RRpi,, irtvrrPP. and invrrp/K hnt (nir 

 white variety aJha wa> el.'arly h h RHp/k Tiiis fornmla- 

 tion brings onr n-nlts iiitn aeeor.l with thosr of Allan! 

 and accounts for the existence of gen.'tically distinct red- 

 flowering varieties. We have now obtaiiU'd fnrthei- evi- 

 dence in support of the correctness of this formnlation. 



4Rid^ay, E., "Color Standards and Color Xonuiu-hitur,', ' • ntlL'. 



