178 



Gigantism in Primula sinensis 



generations produced from self-fertilized F^ plants may show either 

 a considerable preponderance of giants or an even more marked excess 

 of normal (non-giant) forms. 



TABLE V. 



Crosses between Giant and Normal P. sinensis. Results in F^ and 

 subsequent Generations. 



I. Cases in which Giants appear in large numbers. 



Source 

 of Record 



Experi- 

 ment No. 



Sutton II, p. 32 

 Sutton I, p. 71 



Nature of the Cross Results in F^ and f , 



Crimson King x Giant White F2 = 18 giant : 5 non-giant. 

 Fi = Semi-giant Several F^ = plants true to 



giant 



Duchess X Giant Lavender i^2> giant, F3, 18 plants all giant 

 Fi = giant 



U. C. R. 

 U. C. R. 



U. C. R. 



II. Cases in which Giants appear in small numbers, 

 ... 120/07 



... 80/07 



Royal White x Pink Stellata 

 Fi = flowers in massive heads 



Giant Pink x Lord Roberts 

 Star 



Fi — flowers slight sinensis 

 none recorded as giant 



Royal White x Snow King 

 Fi = no flowers recorded as 

 giant 



F2, 67 plants of which 1 = giant, 

 another F2, 54 plants no giants 



F2, 211 plants of which 9 = giant 



14/2/1 Royal White x Snow King F^, 13 plants, 11 non-giant, 

 ~ " " " 2 giant 



^3 > of giant -F2 = 7 plants all 



giant, petals overlapping with 



very fimbriated edges 

 ■^3) of giant ^3 = 14 plants all 



giant, petals overlapping with 



very fimbriated edges 

 F3, of non-giant F2=& plants, 



5 non -giant, 1 giant 

 F3, of non-giant ^2=11 plants, 



none giants 

 F3, of non-giant F2=l plants, 



none giants 



A clue to the significance of this diversity of behaviour is provided 

 by Exp. 120/07 (Table V). In this experiment a true-breeding giant. 

 Royal White crossed with Normal Pink Stellata yielded an F^ in which 

 the flowers though non-giant were borne in massive heads — owing, as 

 shown in Table VI, to dominance of the stellata habit of free-tiering. 



TABLE VL 



Dominance of Stellata over Sinensis Habit of Inflorescence. 



Royal White x Pink Stellata 

 Fi= habit freer than Royal White, pedicels longer 

 2^2=22 stellata habit: 6 sinensis habit 

 in 3 : 1 ratio = 21 stellata habit : 7 sinensis habit 



