A Suggested Interpretation of Certain Cases of Anisogeny

Abstract

MANY cases are known in which the results of reciprocal crosses between green and variegated plants fail to agree. In all these cases the progeny reproduce the appearance of the female parent alone. Cases are also known in which a cross made one way between two true breeding green races results in variegation, whereas in the reciprocal cross the appearance of variegation is either deferred to a later generation or is absent. We know that the female contributes all, or the greater part, of the cytoplasm, and it has therefore been supposed that the cytoplasm, or its inclusions, is partly or wholly responsible for this difference in inheritance. Can this difference in the contribution of the male and female account for the dissimilar results of reciprocal crosses in other characters than variegation?