GENETIC STUDIES IN POLEMONIUM COERULEL'M 2.{ 



Sex-inheritance. 



The female plants witii normal corolla are mentioned al)Ove 

 (p. 20) as having rudimentary stamens, and in some eases llic 

 stamens are more developed than in others, so-ealled intermediate) 

 plants. From this ohservation it seemed already prohable, that 

 the inheritance of sex would be rather complex. The same fact 

 is well known from earlier investigations with other polygamous 

 l)lants (e. g. Corhens with Plantago lanceoUün, Silène Diihjnris, 

 Satureia hortensis, Haunki.kr with Knantia aroensis, Thymus vul- 

 garis, and Miss Pellew with Campanuhi curpatica), and my ex- 

 periments i)()int in the same direction. 



a. The offspring mentioned above under 1 d of 53 individuals 

 with bipinnate leaves consisted of 41 females, 9 females with 

 single more developed stamens and 3 hermaphrodites (thus 50 

 more or less females to 3 hermaphrodites). 



b. In 1917 a white female was crossed with a white hermaphrodite; 

 the offspring (No. 497) consisted of 120 females and 18 herma- 

 phrodites (some with not all stamens well developed). One of the 

 female plants (No. 497 a) was in 1919 crossed with a white 

 hermaphrodite (No. 499 a); the offspring (No. 504) gave only 

 18 females. The same female Fi (No. 497 a) was in 1919 

 also crossed with a blue hermaphrodite (No. 500 a, see also 

 under 3 above); the offspring was 13 females and 9 females 

 with single more developed stamens; thus probably all females. 



c. In 1917 a blue female was crossed with a blue hermaphrodite; 

 the offspring (No. 498) in 1919 contained 39 females', some 

 of which with more developed stamens, and 3 hermaphrodites 

 in which not all the stamens were fully developed. One of the 

 female plants (No. 498 a) was, in 1919, crossed with a blue 

 hermaphrodite (No. 500 a); the offspring (No. 509) contained 23 " 

 females (a few with single more developed stamens) and 4 

 hermaphrodites. Another of the female plants (No. 498 e), one 

 which had some stamens more developed, was in 1919, crossed 

 with the same blue hermaphrodite (No. 500 a); the offspring 

 contained 18 females ' (a few with single more developed sta- 

 mens) and 9 hermaphrodites. 



If we leave the last experiment out as the mother plant was 

 not a »pure» female, we get from these experiments altogether 



^ Two of these were white-flowered and three had bipinnate leaves. 



' Amongst these 11 had bipinnate leaves. ' .\inongst these 8 had bipinnate leaves. 



