Sex-limited inheritance in Lychnis dioica L. 267 



the eggs in the hermaphrodites constitutes no basis for doubting the 

 heterozygous nature of this bisexual form and of its homologous form, 

 the male. 



By the discovery of a unit-character in Lychnis dioica, whose 

 relationship to the sex-characters is the same as that of many sex- 

 limited characters which have been found in animals, it is now possible 

 to completely confirm by a totally new line of evidence, the conclusion 

 that the female in this species is a sex-homozygote, while both the males 

 and the hermaphrodites are sex-heterozygotes, as will be obvious from 

 the data presented below. 



This first sex-limited character of the ordinary sort, to be demon- 

 strated in any plant, is the normal width of the leaves. As in the case 

 of any other unit-character, the existence of the gene B, which, in con- 

 junction with the rest of the Lychnis dioica genotype, XX, produces 

 the broad leaves characteristic of the ordinary strains of this species, 

 could be discovered only when an individual had been found from which 

 this determiner B had disappeared. This important individual was found 

 by BAUE in 1910 in a culture of Melandrium album Garcke (Lychnis 

 dioica L. in part), the parents of which were derived from nature in the 

 vicinity of Sadowa near Berlin, Germany. It is briefly mentioned by BAUE 

 (1911 p. 189) with a photographic illustration in his "Einftihrung in die 

 experimentelle Vererbungslehre". This plant, which was a male, was crossed 

 by BAUE, with broad-leafed females, and the offspring were all broad- 

 leafed, some males and some females. Without knowing that the narrow- 

 leafed character of the mutant had any special significance for the sex- 

 problems, Dr. BAUE generously shared with me his hybridized seeds, so 

 that the Fi was grown simultaneously in 1911 in his garden and in 

 mine, and likewise the F 2 in 1912. This circumstance gave me the 

 pleasure of an independent discovery of the sex-limited nature of the 

 broad-leaf gene, B. BAUE (1912) has published a brief note on his 

 experiences with this form, the further study of which he has, with 

 characteristic generosity, resigned to me. 



I. Description of Lychnis dioica angustifolia. 



From the day on which a seed of this new form germinates it is 

 distinguishable from the broad-leafed type by the longer, narrower coty- 

 ledons (fig. 1). The earlier leaves are linear and nearly grass-like, though 

 the surface, color and texture are not markedly different from those of 

 the typical races of Lychnis dioica. In the adult rosette the leaves of 



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