2r)2 KARL B. KRISTOFFERSON 



A colour-character common to all my lines is the colour of the 

 honey-guide. It was bright yellow and the colour was not modified 

 in so high a degree as the other colours. Its size, however, varied 

 with the season, it was much larger in spring and autumn than in 

 summer. This yellow colour is localized to the chromatophors, which 

 became blue-coloured when sulphuric acid was added. Thus, it was 

 due to carotin. 



Table 5 shows the colour of the parent-lines and the hybrids 

 between V. tricolor and V. arvensis. The colour was determined in 

 the spring. The hybrids between different lines of V. arvensis were of the 

 same yellow colour as the parents. 



The Fi-generations of these crossings were uniform and the reci- 

 procal crosses gave the same results. As shown in the table, the 

 heterozygotism of the colour factors in the hybrids between V. tricolor 

 and V. arvensis appears in the fainter colour of the hybrids; in spring 

 and autumn the lower petals of the flowers were not quite coloured, 

 in the height of summer these petals were of the same yellow colour as 

 in this latter species. For the rest, the seasonal modification was 

 the same as in V. tricolor. 



Only the Fo-generation of the crosses 10 X 2, 3 X 10 and 

 10 X 25 was obtained. The latter two were very small, however. 



The cross 10 X 2 shows a segregation in violet, blue, red and 

 light yellow types. Types with the whole of the spur-petal dark 

 yellow appeared further. The (probable) heterozygotes were easy to 

 distinguish from the homozygotes on account of their fainter colour 

 and the incomplete colouration of the three lower petals. 



As is seen in table 6 the segregation corresponded to the ratio 

 9 : 3 : 3 : 1. Thus the blue colour would be due to a factor B and the 

 red to another factor R. When both B and R are present the colour 

 becomes violet; when both are absent it becomes light yellow. 



The deviation from the theoretical value is a little too high in 

 the group of the red ones and the light-yellow ones. This depends 

 no doubt on the great seasonal modification of the colour of the 

 corolla, especially the red one. If a plant, which is heterozygote in 

 the colour-factors, does not begin to flower before the height of sum- 

 mer and dies away before the autumn it will probably be noted as 

 light yellow. Especially the red colour seemed to be modified in a 

 very high degree. In the hybrids between the red V. tricolor ammo- 

 tropha and V. arvensis the red colour is not at all to be seen in the height 

 of summer. Now and then the red colour of the homozygotes is 



