We may mention a few other in animals, referring the reader for a fuller account to the works cited. One example in the barred character of the feathers in the breed of fowls called Plymouth Rock. In this the female is heterozygous for sex as in _Abraxas grossulariata_, and the barred character is sex-linked. When a barred hen is crossed with an unbarred cock all the male offspring are barred, all the females plain. On the other hand, if a barred cock is crossed with an unbarred hen, the barred character appears in all the offspring, both and females. The female thus transmits the character only to her sons. If we represent the barred character by _B_, and its absence by _b_, we can represent the heredity as follows:-- BARRED FEMALE WITH UNBARRED MALE B female b male X b male b male Bb male bb female Barred male. Unbarred female. Heterozygous. Homozygous. B male B male X b female b male B male b female b male b male Barred female. Barred male. Heterozygous. Heterozygous.] This case is thus exactly similar to that of _Abraxas grossulariata_ and _A. lacticolor_. The barred character like _grossulariata_ is dominant, the unbarred recessive, and to explain the results it is necessary to assume that the female is not only heterozygous for the barred character, but also for sex, with the female sex-factor dominant. The recessive character in this case is linked to the female sex chromosome, or, as Bateson described it, the dominant character is repelled by the sex-factor. We may make a diagram of the kind given by Morgan if we use a rod of different shape for the female-producing sex-chromosome, and use the black rod for the dominant character:-- BARRED female x unbarred male BX uY uX uX | \/ | | /\ | BX uX uY uX BARRED male unbarred female Heterozygous Homozygous BARRED male x unbarred female BX BX uX uY | \/ | | /\ | BX uX BX uY BARRED male BARRED female Heterozygous Heterozygous