hermaphrodite, a male element being possibly concealed in a neighbouring
organ such as the adrenal or kidney. This hypothesis is not supported by
observation of testicular tissue in any such case, but by the condition
found in a hermaphrodite specimen of the common fowl described in the
paper. This bird presented the fully developed comb and wattles and the
spurs of the cock, but the tail was quite devoid of curved or sickle
feathers, and resembled that of the hen. Internally there were two
oviducts, that of the left side normally developed, that of the right
diminutive and less than half the full length. The gonad of the left side
had the tubular structure of a testis, but showed no signs of active
spermatogenesis, but in its lower part contained two ova. The organ of the
right side was somewhat smaller, it had the same tubular structure, and in
one small part the tubules were larger, showed division of nuclei (mitotic
figures), and one of them showed active spermatogenesis.

In discussing Heredity and Sex in 1909, [Footnote: _Mendel's Principles of
Heredity_. Camb. Univ. Press, 1909.] Bateson referred to the effects of
castration as evidence that in different types sex may be differently
constituted. Castration, he urged, in the male vertebrate on the whole
leads merely to the non-appearance of male features, not to the assumption
of female characters, while injury or disease of the ovaries may lead to
the assumption of male characters by the female. This was supposed to
support the view that the male is homozygous in sex, the female
heterozygous in Vertebrates: that is to say, the female sex-character and
the female secondary sex-characters are entirely wanting in the male. This
argument assumes that the secondary characters are essentially of sexual
nature without inquiring how they came to be connected with sex, and it
ignores the fact that the influence of castration on such characters is a
phenomenon entirely beyond the scope of Mendelian principles altogether.
The fact that castration does affect, in many cases very profoundly,