1907.] 



Flower Colour in Antirrhinum majus. 



297 



then the cross-breds would be of one kind only : — 



Yy Ii LI tt Magenta delila 



F 2 has not been obtained yet. 



Crimson Delila x other Types. 



Crimson Delila x Yellow Crimson-striped : — 



The crimson delila parent was breeding true. The other parent was the 

 same individual used in the cross white x yellow crimson-striped. 



Fi consisted of crimsons and crimson delilas. (Table I.) 



F 2 — The cross-breds appeared to be of four kinds, giving respectively, on 

 selfing : — 





Case 1. 

 Crimson x self. 



Case 2. 

 Crimson x self. 



Case 3. 

 Crimson delila x self. 



Case 4. 

 Crimson delila x self. 



Crimson 



„ delila ... 

 Yellow 



56 

 24 

 32 



35 

 17 



20 



8 



23 





Totals 



112 



52 



28 



23 



If we assume the original parents to be : — 



YY ii LL tt Crimson delila 



YYiiLITt Crimson, 



then the cross-breds would be represented by : — 



YY ii LI Tt Crimson (Case 1) 



YYiiLLTt „ (Case 2) 



YY ii LI tt „ delila (Case 3) 



YYiiLLtt „ „ (Case 4), 



whole forms and delilas occurring in equal proportions. 

 From Case 1, on selfing, we should obtain theoretically : — 







Ratios, 



Numbers 

 calculated. 



Numbers 

 observed. 



LT Y 



L Y 





9 or 63 '00 



3 21 -00 



4 28 -00 



56 

 24 

 32 



„ delila... 

 Yellow 



T Y 



Y 









Totals 



16 112 -00 



112 



