176 Gigantism in Primula sinensis 



the very cordial thanks of the writer are due to Mr Leonard Sutton 

 and to the firm's Primula experts, Messrs Macdonald and Tufnail. 



From what has been said already with respect to the mode of 

 inheritance of gigantism in Pisum sativum it follows that the Fi 

 generation resulting from a cross between a pure giant and any other 

 form consists of giants. A like result is not exhibited by Primula 

 sinensis in the ^i generation derived from a similar cross. 



In some instances (see Table IV) the Fi progeny of a cross between 

 a giant and a normal form are of giant type : this is the case, for 

 example, in the Fi of the crosses Giant Pink x Reading Pink and 

 Duchess X Giant Lavender. In other instances, for example, in the 



TABLE IV. 



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



I. Cases in which Gigantism appears to be more or less completely 



dominant. 



Source of Experi- 



Record ment No. Nature of the Parents F, Results 



U. C. R.i 06—7 31 Giant Pink x Reading Pink (Normal) 12 plants of giant type 



32 A Royal White (Giant) x Pink Stellata 14 plants, flowers like 



(Normal) those of Royal White 



( Giant) but freer in habit 

 . and on longer pedicels 



„ ,, 32 F Pink Stellata (Normal) x RoyalWhite 11 plants, flowers like 



(Giant) those of Royal White 



(Giant) but freer in habit 

 and on longer pedicels 



Sutton 2 II, p. 71 Duchess (Normal) x Giant Lavender Giant 



II. Cases in which the F^ is intermediate with respect to Gigantism 



of flowers. 



Sutton II, p. 20 Giant Royal White x Crimson King Semi-giant 



(Normal) 

 „ II, p. 32 Crimson King x Giant White ... 8 plants, semi-giant 



„ I, p. 22 Royal White x Crimson King ... "Habit of flowers 



spoiled " 



III. Cases in which Gigantism of flower appears to be I'ecessive. 



U. C. R. 80/07 Giant Pink x Lord Roberts Star Petals slightly fimbri- 



(Normal) ated ; flowers not re- 



corded as showing 

 giant habit 

 „ 39/08 Lord Roberts Star x Giant Pink ditto ditto 



^ U. C. R. = record of experiment carried out at University College, Reading. 

 ^ Sutton = record of experiment from the record books of Messrs Sutton and Sons, 

 Reading. 



