The sexual life of woman in its physiological, pathological and hygienic aspects

by E. Heinrich Kisch

Düsing, starting from the common belief that all animals have the faculty, when there is a lack of individuals of one sex, of procreating an excess of offspring of the sex which is deficient and thus of restoring the balance between the sexes, maintains that numerous factors, through the co-operation of which the sexual ratio is regulated, act in temporal succession. He shows that the individuality of the mother has an influence upon the sex. But this finds expression through the qualitative constitution of the ovum; hence already before fertilization there must exist a tendency toward the development of one sex or the other—for example, younger ova tend to become females; older ova, on the contrary, to become males. It has further been shown that the individuality of the father, that is to say, the qualitative constitution of the sperm, has an influence in the determination of sex. Thus, by means of the influence of the sperm, the already-mentioned pre-existing tendency of the ovum can in some instances be counteracted and overpowered. The influences in the personality of the father and of the mother, which during fertilization find expression in the qualitative constitution of the sperm and of the ovum, respectively, can thus bring about a resultant tendency, acting in one direction or the other with varying force. Thus, after fertilization, we have this resultant tendency toward the formation of a male or female embryo.

But, Düsing continues, at this time the sex is not definitely determined. The influence of the nutritive condition in which the fertilized ovum finds itself has yet to make itself felt. This influence on the determination of sex through the maternal nutrition, continues (in the human embryo) for as long as three months, but even when the reproductive organs of the embryo have definitely begun to diverge in the direction of the masculine or the feminine type, as the case may be, some nutritive influence, if it is sufficiently powerful, may yet turn the balance in the other direction, so that a partial or complete hermaphrodite results, a being uniting the characteristics of both sexes.

Actual inheritance of sex, of which people used to speak, cannot, in Düsing’s opinion, possibly occur. The mode in which one sex or the other develops is indeed inherited; but the decision which sex shall develop does not depend upon inheritance, but is determined by the co-operation of several outward influences. The qualities by which this is effected are acquired by adaptation to general or special vital conditions.

Wilckens (“A study of the Sexual Ratio and of the Causes of the Determination of Sex in Domestic Animals”) opposes the views of Düsing, on account of the results of his own investigations, relating to the births of 30,000 domestic animals. He formed the following conclusions:

1. Locality (soil and climate) has an influence upon the sexual ratio and upon the determination of sex in domestic animals, but this influence is probably indirect only, being exerted through the intermediation of the nutrition of the embryo in utero.

2. The season in which the domestic animal is conceived affects the sex; the hot season favours the production of males, the cold season that of females; in the hot season, in general, the appetite and nutrition of domestic animals diminish, whereas in the cold season these increase.

3. Regarding the male progenitor, neither his age, nor his sexual energy, nor the demand made upon that energy, nor the age of the semen, has any influence upon the sexual ratio or the determination of the sex of the offspring.

4. The age of the female progenitor influences the sexual ratio and the determination of the sex of the offspring in this way, that in general, primiparæ and young mothers conceive a larger number of female offspring. This influence of age may be referred to the fact that in general young mothers nourish their offspring in utero better than older mothers.

5. The nutrition of the fruit in utero influences the determination of sex, speaking generally, in the following way, that better nutrition favours the determination of the female sex, worse nutrition favours the determination of the male sex.

6. In addition to the influence of nutrition of the fruit upon the determination of sex, other influences, whose nature still remains obscure, must also co-operate, because one and the same progenitor in similar nutritive conditions does not always procreate offspring of the same sex.