322 THE AMEBIC AX NATURALIST [Vol.L 



flowering time by about three weeks. The early variety 

 was white-flowered, the late variety red-flowered. The F 4 

 hybrids were only a little earlier than the late variety in 

 time of flowering and of course had red flowers, this 

 being a dominant character. The F 2 hybrids varied in 

 time of flowering throughout the range of both parent 

 varieties and all intermediate points, but not beyond the 

 range of the parents. Hoshino divides the F 2 plants into 

 two main groups, an early flowering and a late flowering 

 group, the two being separated naturally by a class of 

 "minimal frequency" usually recognizable. A majority 

 of the plants in the early flowering group had white flow- 

 ers, a majority in the late flowering group had red flowers. 

 This result shows that early and late flowering have a 

 tendency to segregate from each other as Mendelian alle- 

 lomorphs and that time of flowering is coupled with 

 flower color. This fact of coupling, first observed by 

 Lock, alone would suffice to show that time of flowering 

 is inherited as a Mendelian character. The fact that the 

 F 2 individuals apparently fall into two main groups, not 

 into four or eight, indicates that one important Men- 

 delian factor is concerned, not two or three. But Hoshino 

 found that in F 3 four (not two) groups of relative con- 

 stancy were obtained and this has led him to suppose that 

 the inheritance of time of flowering depends upon two 

 independent Mendelian factors, one of which (A, a) de- 

 termines late or early flowering, while the second (B, b) 

 supplements or modifies the action of A. He regards A 

 as the principal factor, with which alone flower color 

 shows coupling. The action of B is regarded as subsidi- 

 ary. A characterizes late-flowering plants ; a, early-flower- 

 ing plants. B makes the flowering time later than it 

 would be otherwise; b of course makes it earlier. The 

 four supposedly homozygous sorts which are recognized 

 are of the following formulae: 



aabb, early; aaBB, intermediate early; AAbb, inter- 

 mediate late; AABB, late. Since red color of flowers is 

 by hypothesis coupled with A, red flowers will predomi- 

 nate in the last two groups, white flowers in the first two 



