274 Toyama. 



On comparing the above summaries with Coutagne's we clearly 

 see that both come in the same category. In accordance with our 

 expectation they obtained three kinds of Fj broods, each of them 

 when paired inter se segregated into white and yellow in F2. In the 

 case where white dominates in Fx, there occur in F2 3W : lY, whereas 

 when yellow dominates in Fi the reverse is the case in F2, that is 

 to say, iw : 3Y, whüe Fi white mated with F^ yeUow jdelded a 

 mixed F2 consisting of iw : lY. 



As to the proportion of white and yellow in each mating we 

 found few inconsistent figures. Of Kellogg's 65 F2 matings we enume- 

 rated only four matings which gave such inconsistent figures that some 

 of the average proportions are disturbed. They are marked with au 

 asterisk in tables VII and VIII. 



Thus far our expectation is closely realized by the facts of their 

 experiments and we have now little hesitation in regarding those 

 whites studied by Coutagne and Kellogg as mixed races of dominant 

 and recessive whites. As to the order of inheritance, they are quite 

 regular and Mendelian, dominant white always behaving as epistatic 

 and recessive as hypostatic towards yellow. 



Double mating. 



KeUogg's perturbation in the order of inheritance by double 

 mating seems to us to be the effect of the mixed breed referred to in 

 the preceding pages. 



Before considering his results, let us see what effect would be 

 produced if the mixed white was mated doubly with its own male 

 and another yellow male, or vice versa. 



I. Yellow females doubly mated with white and yellow males. 



As the yellow is homozygous yy and the white is a mixture of 

 wvv, Ww and w^v, we expect to have the following gametic com- 

 binations in Fl- 



2 yellow X c5 (white and yellow). 



1. 2 YY X (5 (W'W 4- YY) = \VY + YY = a mixture of i W : i Y. 



2. 9 YY X d C^'w + YY) = (WY -)- wY) + (YY) = a mixture of i W : 3 Y. 

 3- 9 yy X (5 (ww -|- YY) = wY + yy = all yellow. 



Two kinds of Fi broods are produced, orte being a mixture of 

 white and yellow, another all yellow. 



Of the mixed broods produced by the first and second matings, 

 the proportion of white and yellow would be i : i in the former and 



