F. Keeble and C. Pellew 53 



flowering (Table I) that the Fi generation is intermediate with respect 

 to time of flowering between the parents Autocrat and Bountiful. In 

 1909, whereas 23 out of 28 plants of Bountiful blossomed by June 2nd, 

 and whereas Autocrat was beginning to flower by June 30th, 10 of the 

 plants of Fi (of a total of 12) were in flower by June 21st; and the 

 remaining plants were in flower by June 30th. The i^i plants of 

 Autocrat crossed Bountiful and those of the reciprocal cross, grown in 

 1908, confirm this result. From the appearance of such an intermediate 

 form in i^i, it may be supposed, either that there is incomplete dominance 

 of lateness over earliness, or that there are two (or more) factors con- 

 nected with the time of flowering ; the meeting of the two, or more, 

 dominant and antagonistic factors, from either parent in the Fi plant, 

 giving an intermediate time of flovvering. In the former case, the F^ 

 plants, obtained by selfing F^, may be expected to give the 1:2:1 

 ratio ; but, though segregation of early and late occurs in F^, it is not 

 of this simple type. If we tabulate the observations on time of flower- 

 ing, not of the F2 generation as a whole, but of the several categories 

 of that generation, viz. thick long (TL), thick short (Tl), thin long (tL), 

 and thin short (tl), we obtain the results shown in the accompanying 

 Table. 



TABLE I. 



The Accelerating Influence of Long Internodes on Time of Flowering 



of F„ Plants. 



(Times of Flowering of Bountiful, Autocrat and F^ are given for purposes of comparison.) 



Numbers of Plants in Flower 



F; 



beginning 

 to flower) 



These results show that plants with long internodes, of both tliick- 

 and thin-stemmed types, flower, on the whole, earlier than the short 

 internode types. Since long internode is dominant to short internode, 

 Fi plants may be subject to the same accelerating influence with respect 

 to time of flowering as those of the groups, long thick and long thin. 



