CROSSINGS IN MliLANlUM-VIOLKTS 287 



not be due to one single Mendelian factor only as herkogamy probably 

 depends on three mori^hological characters, viz. the (levi'l()i)nient of the 

 labellum, the direction of the opening of the stigniatic chaini)er, and 

 the nature of the pollen -magazine (more or less closed). All these 

 characters were found to \ary independently in l-.^. Further, the Fi 

 generation of a cross with another herkogamous V. tricolor (40 X 3) 

 was autogamous. 



2. Fl of the cross between the violet flowering V. tricolor (lOj 

 and the light-yellow V. arvensis (2) became violet. F 2 showed dihy- 

 brid segregation in 9 violet : 3 blue : 3 red (red violet) : 1 light-yellow. 

 The blue colour is due to a factor B. the red to another factor R. 

 When both are present [BR\ the petals become ^ iolet, when absent 

 {br) they become light yellow. 



3. The dark-yelloNv honey-guide was of the same appearance in 

 the ])arent lines and in Fi of this cross. In F 2 types appeared with 

 the whole of the spur-petal of the same dark-yellow colour as that of 

 the honey-guide. The ratio was about 15 with small hcmey-guide : 1 

 with the whole of the spur-petal dark yellow. 



4. When types with a dark-green spot on the front of the style 

 were crossed with types without the spot this character was found 

 to be dominant in Fi. F^ -showed monohybrid segregation. Thus, 

 this character was due to one single Mendelian factor (S). 



5. A form with white-spotted leaves of about the same appea- 

 rance as most of the albomaculata forms was found in V. arvensis. 

 It bred true as to this character. Ft became normal green leaved 

 when crossed with normal green and F^ showed mon()hy])rid segrega- 

 tion. The albomaculata-character was due to the absence of one 

 factor (A). 



6. As to the size of the corolla, determined by measuring the 

 upper petals and the spur-petals, two types were noticed; one with 

 very small flowers and another with relatively large. When crossed 

 with a large the small-flowering type was found to be dominant. When 

 a large flowering was crossed witli another large flowering the largest 

 flowers were more or less dominant. F^ of the first mentioned cross 

 showed a continuous variation and most of the plants had a size of 

 petals approaching that of the small-flowering parent. 



7. The variation of the size of the labellum in the crossings was 

 similar to that of the petals. Thus, the Fi -generation had a labellum 

 of about the same size as the smaller parent, and most of the F^-indi- 

 viduals were grouped around the mean of this parent. 



