^272 



KARL B. KRISTOFFERSON 



TABLE 10. The length of the spur-petal in cross 2 X 10. 



TABLE 11. The length of the upper petals in cross 2 X 10. 



The variation runs in a continued series between the limits of 

 the parents. Probably it is also transgressive although the number 

 of individuals is a little too small for definite estabHshing of the be- 

 haviour in this case. 



The arrangement of the elements of the series is rather skew. 

 Most of the individuals had a length of the petals approaching that of 

 y. arvensis; only a few of them had a size of about the same as 

 y. tricolor. It is less evident with regard to the spur-petal of the 

 7^\-generation which depends on the rather inconsiderable differences 

 in the length of the spur-petals of the parents. It is more pronounced in 

 the case of the upper petals. The mean of Fo lies much nearer the mean 

 of y. arvensis than that of V. tricolor, as is seen in table 11, As the 

 number of individuals is small I think it useless to give the values 

 of the skewness; they would be too uncertain. 



The dominance in Fi and, partly, the skewness of the variation 

 in Fa would be explained by the assumption of an inhibiting factor 

 for the length of the petals in V. arvensis. This factor shows (pro- 

 bably) complete dominance, and its effect may be much more im- 

 portant than that of any positive factors for the size of the 

 corolla. 



