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. 



Nature of the Cross 



Sutton II, p. 32 



Sutton I, p. 71 



11. 



U. G. E. 

 U. C. B. 



U. C. E. 



Results in F2 and F3 



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

 F] = Semi-giant Several F3 = plants true to 



giant 



Duchess X Giant Lavender Fo, giant, F3, 18 plants all giant 

 Fi = giant 



Cases in which Giants appear in small numbers. 



120/07 Eoyal White X Pink Stellata F2, 67 plants of which 1 = giant, 

 Fj = flowers in massive heads another F^, 54 plants no giants 



80/07 Giant Pink x Lord Eoberts jP.,, 211 plants of which 9 = giant 

 Star 

 Fi = flowers slight sinensis 

 none recorded as giant 



14/2/1 Eoyal White x Snow King Fo, 13 plants, 11 non-giant, 

 Fi = no flowers recorded as 2 giant 

 g''^"* F3, of tiiant F2 = l plants all 



giant, petals overlapping with 

 very fimbriated edges 

 Fj, of ifiant ^3 = 14 plants all 

 giant, petals overlapping with 

 very fimbriated edges 

 F3, of non-giant F.} = G plants, 



5 non-giant, 1 giant 

 F3, of non-giant ^0=11 plants, 



none giants 

 Fj, of non-giant F-^=7 plants, 

 none giants 



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

 by E.xp. 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 VI. 



Dominance of Stellata over Sinensis Habit of Inflorescence. 



Eoyal White x Pink SteUata 

 Fi = habit freer than Royal White, pedicels longer 

 Fo = 22 stellata habit: 6 sinensis habit 

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



