But what was now wanting was an experiment that could be added to the preceding, and would serve to show that a human female, who, under the influence of our method of dieting, invariably bore sons, would, in the case of paying no attention to diet, bring a female into the world.
The evidence was forthcoming, for the woman in question again became pregnant without any consideration being bestowed on her bodily condition, and without anything being done to remove the traces of sugar from the urine. After having seven times borne males she became this time mother of a female, which, born before the due time, soon died. After that she was not again pregnant. Probably some change supervened in consequence of which she became permanently unfruitful.
This incident shows sufficiently that the ovum in the case of the woman who served for our experiment possessed an inherent tendency to develop into a female, and was also ripe enough to be fertilized. As we had exercised no influence upon it so as to effect any change in the ovum (in the same way as we had previously been able to affect the others by the diet in order to procure the ovum of a male) the result was a female.
The female tendency was therefore already present in the ovum, and indeed the mother supplied convincing evidence of the female constitution of the ovum whilst it was yet unfertilized, because sugar existed in her urine. The previous determination of the sex could also in this case present no difficulty. In the earlier cases, when male individuals followed one another, we always aimed, by means of our support given by means of the nourishment of the mother, not only at the ripening of the ovum which was to be fertilized, but also at the development of a male individual. In the last case the ovum was, without any assistance, capable of being fertilized, but it developed into a female.
A ripe, fertilizable ovum in the ovary of a woman whose urine habitually contains sugar has a tendency, when the proper conditions are supplied, to develop into a female. In consequence, it is in such cases from the outset possible, without exercising any influence over the mother, without adopting any diet, to anticipate after a conception, the birth of a female individual. But if these conditions do not exist, if no sugar can be detected in the urine, the use of the same influence in order to obtain a male individual is still not superfluous. In this case also there is a need of an alteration of diet, although the individual in question accomplishes the process of physiological combustion in a manner which must be called the most favorable possible, seeing that with a mixed diet all the oxidizable materials are completely used up.
Supposing that a mother of this sort wished for female offspring, one would not be in a position to give any advice. In this case one cannot, according to the facts which have been mentioned above, exercise any influence over an alteration in the course of the development of the ovum which would occasion the birth of a female. Such a mother is, up to the present time, beyond the reach of an influence that can affect the development of the future sex.