F Keeble 181 



The first is an undoubted giant, the last is an undoubted non-giant, 

 the two others are of the constitution of the F, parent, namely hetero- 

 zygous for C, and although the parent arising in a family of smaller 

 forms was classified as a doubtful giant, these plants now that they are 

 seen side by side with the more massive (AABBCC) plant are thrown 

 unceremoniously into the category of minor forms. Classified thus the 

 Fi consists of : 



1 giant : 3 non-giant 



in seven plants 1'75 „ : 525 „ expected 



2 „ : o „ found. 



If the ultimate object of Mendelian analysis were merely to fashion 

 constitutions on slender experimental bases, an hypothesis such as 

 that now in course of formulation would be scarcely worth the 

 making ; but it must be remembered that one of the prime objects of 

 Mendelian analysis is to provide classification with more subtle methods 

 than those on which it relies at present ; and, as is shown immediately, 

 the hypothesis now in course of adumbration does lead to a better 

 system of classification of the cultivated forms of P. sinensis than could 

 be obtained by any other method whatsoever. 



The validity of the assumption that well-marked gigantism may 

 only be manifested by plants which, whilst possessing a certain factor 

 C in the homozygous or heterozygous condition, are pure with respect 

 to the presence of the other two factors (AA) and (BB) is borne out by 

 the results of experiment 80/07 (Table V). In this experiment a true 

 breeding giant (AABBCC) Giant Pink was crossed with Lord Roberts 

 Star which by reason of its delicate habit of flower may be regarded as 

 of the constitution aabbcc. 



Giant Pink x Lord Roberts Star, 

 AABBCC X aabbcc 

 = F, : AaBbCc, 

 and such an F^ on self-fertilization yields an F2 composed of : 



giant and r 1 AABBCC 

 approximately J lAABBcC : 61 non -giants 

 giant forms I lAABBCc 

 = in64 plants: 3 : 61 

 = „ 211 „ 9-9: 2011 



actual F, = 9 : 202. 



