Schenk's Theory: The Determination of Sex

by Samuel Leopold Schenk

The appearance of sugar in the urine does not occur only amongst women of the upper classes, who enjoy a better and varied diet, but also amongst those of the poorer classes, who are obliged to subsist chiefly upon vegetable food.

Indeed, in the case of vegetarians who take concentrated albuminous substances only in the form in which they occur in eggs, and get animal fat and sugar from milk alone, the urine, as regards the occurrence of sugar, is of the same character as that of those who do not adhere to vegetarianism. Women, who, in other climes, are not within the reach of our investigations, might also be included in the same category so far as their diet is concerned.

It follows that the individual does not excrete sugar only in consequence of the character of the diet, but that the processes of combustion manifest themselves in the results derived from the digestion of the different nutriments.

Now, an indispensable condition of the ripening of the ovum in the female organism is that the metabolic process shall be normal. When these changes are being effected as perfectly as possible, sugar is entirely absent from the urine. The female individual may have arranged and chosen her diet from the different groups of food in any conceivable way, and she may belong to this or that class of the community, but the metabolic processes—that is to say, the combustion processes—are, nevertheless, those which deserve most attention in connection with the development of the ovum.

Ovulation is never in any case altogether independent of the influences of diet and metabolism. In those cases where the combustion is of such a kind that unoxidized remains of bodies still capable of producing heat are found in the urine, the ovum in process of development in the human female is never so highly developed as in the cases where no sugar, or at least no recognizable trace of it, can be found in the urine.

In the first case we shall have not only a less ripe ovum, but very likely also a less well-nourished ovum. An ovum of this sort has not so fully attained to all the characteristics and powers inherent in its protoplasm, and, in consequence, seems fitted to develop only a female individual. In such an ovum the several cell-products of the ovum, which have to develop themselves into the future embryo, will be arranged for the growth of a female. Not only will female organs of generation be developed from it, but also all the elements of the future individual will be feminine.

On the contrary, if in the mother-individual all the substances developed in, or taken into, the organism undergo combustion in such a manner that no sugar is found in the urine, not even in the smallest quantities, then an ovum can be developed such as is required to produce a male individual. Out of its protoplasm in the course of evolution elements form themselves, whence male cells are developed, which correspond to the development of tissues and forms of the male individual. Some of the cells—viz.: those which ultimately become the elements for the continuation of the species, are planned for the male sex.

It follows from all this that the result depends to a great extent both upon the diet chosen, and upon whether it has been rightly chosen to suit the organism, whether it is possible to exert such an influence as may so support the ovum in its maturation that in its development it may form itself into a male individual. It must be observed in advance that such an influence as may be effective for the production of sex must not be applied to an already fertilized ovum, but must be applied to an ovum in development before its fertilization.

Indeed, it is even of greater importance to know that the mother individual has been for a considerable period anterior to the fertilization of the ovum provided with the requisite food. Care must also be taken that after conception a similar befitting diet is continued for the mother, which diet should resemble that previously provided.