1907. J Flower Colour in Antirrhinum majus. 299 



Crimson Delila x Yellow : — 



Both parents were breeding true. 



Fi gives the expected result, namely, all crimson delilas. (Table I.) 



F2 has not yet been obtained. 



Crimson x other Types. 



Crimson x Yellow Criinson-strijped : — 



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

 used in previous crosses. 



Fi consisted of crimsons only. (Table I.) 



F 2 — Only one cross-bred gave seed and the offspring were crimsons and 

 yellows. The numbers are too small to be of value. 



If we assume the original parents to be : — 



YYiiLLTT Crimson 



Y Y ii LI Tt Yellow crimson-striped, 



the cross-breds would be : — 



YYiiLl TT Crimson 



YYiiLITt 



YYiiLLTT 



YYiiLITt 



All therefore are crimsons, and of these, one, on selfing, namely, YY ii LI TT, 

 would give crimsons and yellows. 

 Crimson x Yellovj : — 



Fi gave the expected result, namely, all crimsons. (Table I.) 

 F 2 has not yet been obtained. 



EOSE X OTHER TYPES. 



The type rose has ivory lips tinged with magenta and a pale magenta tube. 

 The individuals used in crossing were found to breed true. Crosses were 

 made between this and most of the other types, but sufficient numbers have 

 not been obtained in F 2 to give a reliable indication of the results. A type, 

 where " rose," i.e., a tingeing with magenta, is superposed upon a yellow ground 

 (the case where the factor I is missing), appeared in F 2 , together with delila 

 forms of both types ; this would lead to the supposition that " rose " may be 

 represented by a Mendelian factor. 



An interesting point has arisen in connection with the cross rose x a deep 



crimson delila. The cross-bred is a deep magenta, in which the tube takes 



the same shade as the lips. This fact suggests, as pointed out elsewhere 



(p. 301), that there may be a coupling between the shade of tube- and lip- 



vol. lxxix. — b. z 



