52 Mr Bateson, Note on the Resolution of 



The offspring of self-fertilisation he represents as 



It was found by experiment moreover that F x D gives the 

 red again. Other experiments showed that one of the D plants 

 produced only D, and one of the F plants produced only F off- 

 spring ; that other D plants might give a mixture of D plants and 

 white plants ; and that other F plants might give a mixture of 

 F plants and white plants. Finally some red plants gave reds and 

 F plants, while others gave reds and D plants. 



In de Vries' account it seems to me that great complication is 

 introduced by the attempt to express the unresolved red as F + D ; 

 and the representation of white by W + W is still more open to 

 objection, for here at least there can be no reason to suppose two 

 characters concerned. In fact the white is only represented as 

 W+ W because it is crossed with a compound character. 



These difficulties, and others to which they lead, do not yet 

 seem inevitable, and one is tempted to look for a simple account. 

 Assuming the distribution of offspring to follow the ratio 

 9 R : 3 F : 3 D : 1 W, this result would equally be arrived at on 

 the hypothesis that the hybrid of red x white, R x W, produced 

 equal numbers of gametes of each sex having the characters R, F, 

 D, W, respectively. The fortuitous union of these would give 

 9 R : 3 F : 3 D : 1 Was before. The actual composition of the 

 offspring would be as follows : — 



The 9 R = 1 RR + 2 RF + 2 RD + 2 RW + 2 FD 

 The 3 F =1FF +2 FW 

 The 3D =II)D + 2DW 

 The 1 W = l WW. 



We know from the experiments that R is dominant to both F 

 and D ; that F and D are each dominant to W ; and that F x D 

 gives R. 



On this hypothesis the serious theoretical difficulties inherent 

 in the other view are avoided. Far more than a mere question 

 of notation is involved. On de Vries' view the gametes must 

 have the four forms FD, FW, WD, WW, so that the white 

 character would be present in three out of the four gametes, 



