166 



Gigantism in Primula sinensis 



abnormally petalled plants was continued only for a few generations 

 the negative results cannot be claimed as decisive. 



TABLE I. 



Selection Experiments tvith White Queen Star {W. Q. S.). 



W. Q. S. from seed 



no abnormality observed. Selfed W. Q. S. 



some plants with occasional 6-petalled flowers 

 selfed a 6-petalled flower 



plants with most flowers normal, a few with 6 or 7 petals 

 selfed a 



7-petalled flower ditto ditto 



5A bB oD 



1903 



1904 



Fi 1905 



Fi 1906 



F, 1907 



^4 1908 



Ffi 1909 



Fe 



F7 

 F» 



1910 

 1911 

 1912 



10 plants 

 petals slightly 

 fimbriated 



8 with 1 or more 

 6-petalled flowers 

 flowers large 

 selfed 



11 plants 

 all giant 

 (see Table 11) 



selfed 



I 

 = 10 plants 

 all giant 

 selfed 

 = giant 



— giant 

 = giant 



12 plants 

 11 normal 

 1 with 1 flower 

 with 6 petals 



selfed 



6 plants 

 all normal 



4 plants some 

 flowers with 

 supernumerary 

 petals 



selfed 2 plants 



selfed 



all normal 



13 plants 

 aU normal 



selfed 



all normal 



selfed 

 = normal 

 = normal 

 = normal 



12 plants 

 5 normal 

 7 with 

 occasional 

 6-petalled flowers 



It may be added that, as shown in Table I, the habit of forming 

 supernumerary petals has not manifested itself in later generations 

 to so marked a degree as it did during the time of the selection- 

 experiment, and that the race of White Queen Star now growing 

 at Reading, which consists of descendants of the 6- or 7-petalled 

 plants, is not distinguished to any marked degree by this abnormality. 



The interest attaching to the series of experiments which has just 

 been described lies, however, in another direction. For it was in the 

 course of these experiments that a Giant variety of White Queen 

 Star was obtained. The mode of origin of the Giant race is set 

 forth in detail in Table II. 



As indicated in Table II, gigantism manifested itself in the Ft 

 generation (1908). That generation, which was composed of 11 plants, 

 consisted of giant forms only. The striking appearance presented by 



