258 KARL B. KRISTOFFERSON 



We assume: 



A to be the factor for closed pollen-magazine, 



B » » » » » antrorse stigmatic chamber. • 



C » » » » » small labellum (the small labellum was 



dominating, as shown in tables 1 and 2). 



If the assumed factors A and B are called factors for herkogamy 

 and the factor C the factor for autogamy it is not impossible that 

 the autogamy- factor changes the effect of one of the factors for 

 herkogamy, and the plant (formulae AbC or aBC) becomes autoga- 

 mous. When both these herkogamy-factors and the C-factor are 

 present {ABC) the plant becomes herkogamous. This may be the 

 case in Fj. If only one of the factors for herkogamy is present and 

 the C-factor is absent {Abe or aBc) the plant would also become 

 herkogamous. 



The segregation would be: 27 ABC : 9 ABc : 3 Abe : 3 aBc, all 

 herkogamous and 9 AbC : 9 aBC : 3 abC : \ abe, all autogamous. 

 Thus, the ratio becomes 42 herkogamous : 22 autogamous. The 

 theoretical numbers in the above mentioned Fo-generation would be 

 about 64 herkogamous and 33 autogamous plants. The observed 

 numbers were resp. 68 and 29. If the segregation was a monohybrid 

 the theoretical numbers would be 73 : 24. 



I do not think that this statement is quite correct; it is presented 

 only to show how this segregation, which beyond doubts is polyhybrid 

 might give impression of a monohybrid. In Viola the case may pro- 

 bably be still more complicated. The number of individuals, however, 

 is too small to make possible a complete genetical analysis of this 

 segregation. The measurements in addition are very difficult to make, 

 and so it will become a very tedious work to investigate a larger 

 numbers of individuals in F2. It may further be necessary to in- 

 vestigate the Fs-generation. 



An interesting fact was the appearance in F^ of three plants 

 w'hich — probably on account of the construction of their flowers — 

 were almost excluded from pollination even if insects were allowed to 

 visit the flowers. 



Table 3 shows the number of seeds in each capsule of the in- 

 dividuals of the parent lines and of Fi. The number of seeds is a 

 little greater in the arvensis-]\ne (2) than in the /r/ro7or-line (10). The 

 variation, on the contrary, was larger in the latter. This depends 

 very likely on the fact that this latter line w'as herkogamous. The 

 arvensis-line (2), being autogamous, secured automatically a rich 



