TH E 
NEW PflYTOIiOGIST 
Vol. IX., Nos. i & 2. Jan. & Feb., 1910. 
[Published March 2nd.] 
RECENT ADVANCES IN THE STUDY OF HEREDITY 
(A Course of Lectures, for the University of London, delivered in the 
Summer Term, 1909). 
By A. D. Darbishire. 
LECTURE VII. 
Cytological and Other Evidence Relating to the 
Inheritance of Sex. 
B EFORE passing to the main subject of this Lecture, i.e., 
to a consideration of those phenomena which point to the 
male as being heterozygous for sex, reference may be made to 
certain theories of sex-inheritance in man. Theories have been 
held, and suggestions made, on the cause of sex since the time of 
Hippocrates, who thought that males resulted from the mixing of 
the products of the right generative glands of the male and female, 
and females from the products of the left. This theory was revived 
by Hencke in 1786 and has been brought forward again recently, 
in a modified form, by Dr. Rumley Dawson. 1 According to Dr. 
Dawson the female determines the sex of a child: the right ovary 
gives rise only to potentially male ova, the left to female ova. 
The evidence advanced in support of this view is very unsatis¬ 
factory : for the data of greatest value bearing upon this hypo¬ 
thesis, viz., the sex of children borne by a female on whom 
unilateral ovariotomy has been performed, is rendered worthless 
from the acknowledged impossibility of being certain whether the 
whole ovary had been removed, and by the known fact that 
fragments of an ovary may liberate ova capable of fertilisation 
and development. Dr. Dawson’s book is, however, interesting, 
1 G. Rumley Dawson. The Causation of Sex. London, 1909. 
[H. K. Lewis]. 
