INHERITANCE OF SEX IN LYCHNIS: 
GEORGE HARRISON SHULL 
(WITH TWO FIGURES) 
Since CorrENs (4) made his brilliant investigations with Bryonia, 
in which he showed that crosses between the monoecious B. alba 
and the two sexes of the dioecious B. dioica do not give equiva- 
lent results in regard to the sex of the offspring, and since Don- 
CASTER and Raynor (6) published their equally interesting studies 
with the currant moth, Abraxas grossulariata, and its variety 
lacticolor, in which it was found that reciprocal crosses were not equal 
with respect to sex, but that the Mendelian color character of the 
variety Jacticolor is sex-limited, the interest of all students of genetics 
has been more or less strongly directed toward the problems of sex 
inheritance, and toward the attempt to describe or explain the heredity 
of sex on the basis of Mendelian inheritance. 
It has been of great interest to find that these two classic cases of 
Bryonia and Abraxas apparently lead to opposite conclusions as 10 
which sex determines the sex of the offspring, but both seem to favor | 
the conception that one sex is homozygous with respect to sex, and 
the other heterozygous. BATESON (1) attempts to make the results 
with Bryonia agree with those in Abraxas, but his interpretation is 
certainly not as simple as that of CorRENS. BATESON’S explanation 
would require that Bryonia alba be gynodioecious, having larger 
numbers of pure females than of monoecists, instead of being 
wholly monoecious as described in the manuals. It does not seem 
likely that so striking a relation as this would have been over 
looked by the taxonomists. Moreover, in the attempt to bring 
harmony between Bryonia and Abraxas, BATESON introduces fully 
as fundamental inharmony between the two species of Bryonia, when 
he assumes that the males of B. dioica are pure males with pollen 
bearing only the male character, while the pollen of B. alba is all 
female. Certainly we are justified in expecting a more complete 
t Read by invitation before the American Society of Naturalists, Boston, Decem 
ber 28, 1909. 
Botanical Gazette, vol. 49] Lrt8 
