256 Proceedings of the Royal Physical Society. 
and is associated with the great activity of the ovaries at this time. In those 
cases in which the ovarian tissue was not actively functioning or capable 
of functioning, the wartiness was not developed. There is a suggestion. 
here, therefore, that this peculiarly female secondary sexual character is 
expressed in response to the stimulus provided by the ovaries in a certain 
state of physiological activity. 
Case No. I. could function and behave as a female; No. II. could function 7 
as a female possibly, but it is reasonable to wonder if a rutting male would 
have recognised this individual as a female, since the secondary sexual 
characters were of the male pattern. On the other hand, this individual 
could function as a male, yet it is questionable if it was sufficiently male to 
behave as one. The finger-pads are developed in anticipation of the nuptial 
embrace. ta 
The others were equipped in such a way that they must have functioned 
and also have behaved as males, although in their gonads various amounts 
of pathological ovarian tissues still remained. 
The question naturally arises as to whether these individuals are 
chromosomally females which become converted into males, or chromosomally 
males with an initial deficiency of the male-determining substance. The 
existence of sex-chromosomes has not yet been demonstrated in frogs, but 
it may be assumed that in these, as in other animals, sex-determination is 
effected by such a mechanism. Further, it is reasonable to assume, as 
Huxley points out,’ that the frog is of the @XX,fXY type. This being 
the case, then these individuals, XX in composition, instead of developing 
into normal females, became transformed into “somatic” males by the action 
of some factor or combination of factors which over-rides the chromosome 
constitution. They have the chromosome constitution of the female sex, 
but the actual organisation of the male. The mating of such individuals, 
functioning as males, must disturb the sex-ratio of the next generation, and 
this fact may explain the unusual sex-ratios recorded by many authorities. © 
1 Journal of Genetics, vol. x., No. 4, Dec. 1920. 
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