1 7 1 LOCK : STUDIES IN PLANT BREEDING 



similar result was however obtained in F 1 (w x b) ; the whole 

 fit- in with Mendelian expectation, and there does not appear 



i >e any other explanation of equal simplicity. The expla- 

 oation given does not preclude the possibility that the differ- 

 ence between the plants yielding 100 per cent, b and those 

 yielding 80 per cent, b may depend on a definite factor. 



In F 2 , in all three cases, the proportion of wb : w (b) was 

 nearly 2 : 1 on the average. From this it seems likely that in 

 case (1) the products of gametes w x b and b x w is the same. 

 This differs from what took place in F, and is the contrary of 

 what Correns supposes in the case of his cross " alba " x 

 " cyanea." 



According to the present view, among the offspring in F 3 of 

 wb grains, blue was, in the case of most plants, dominant 

 over white in every grain. But in the offspring of w (b) the 

 result was more often like that which appeared in the case of 

 w x b in F,, blue being now dominant in certain cases. It 

 is clear therefore that the degree of dominance (or valency) 

 of blue is inherited to some extent, but the experiments are 

 not precise enough to justify a more definite statement 



In the case of the offspring of the mongrel crosses in which 

 the blue grains were of the flint form, whilst the white grains 

 were derived at first from the same mixed flint strain, and 

 later from a definite strain of dent corn, dominance of blue in 

 all t he grains of a plant was the exception even in the offspring 

 of wl) (or bb) grains. This is in accordance with (Wrens's view 

 that the white character derived from a BUgar strain is 

 "weaker*' in comparison with blue than the same character 

 • h-rived from a flint variety. 



In the preceding case of a definite cross, the difference 

 between the offspring of ww and w (l>) was very distinct. In 

 t lie exam [tie last, described this was not the case, the distinction 

 heiiiL: doubtful in the case of one or two plants; but it is 



Lined thai the two classes are distinct in fact, because in 

 this wray the simplest possible explanation seems to be 



an ived at . 



