Oll the varying diiininanct- of ct-rlain white breeds of the silk-worm, etc. 283 



a) F2 whites paired inter se. 



1 . \Vw X Ww = WW -|- 2 Ww + WW = all white. 



2. Ww X WY = WW + WY + Ww + wY = 3 whites : 1 yellow. 



3. Ww X WW = Ww -\- WW = all white. 



4. W'Y X WY = WW + 2 WY 4- YY = 3 whiles : i yellow. 



5. W Y X WW = Ww -f- wY = one white : one yellow. 



6. WW X WW = WW = all white. 



b) F2 yellow paired inter se. 



I . wY /: wY = WW -|- 2 wY -\- YY = 1 white : 3 yellows. 



Thus some F2 whites will give all white F3 broods, some 3W' : i Y 

 broods and the rest iw : i Y broods, and the F2 yellow only iw : 3y 

 broods. 



The order of inheritance of white and yellow characteristics in 

 this series of matings is: 



Y) 



Now we shall quote here the results of Kellogg who crossed 

 Bagdad white females doubly with Bagdad white and Italian yellow 

 males. 



Of his four matings, one produced all white F^ which has been 

 already discussed in the former pages, two a mixed F^ consisting 

 of white and yellow in various proportions, and the last one all 

 yellow Fl. 



Induktive Abslamnuings- und Vererbungslehre. VJI. 



