Of what kind the means of impulse are, the juices are, which occasion this I do not know. I can only supply the conditions requisite for them; I can see only whether they are present. And so I again come back to this, that we may expect a male individual from the ovum when the juices are developed which serve as a functional means of impulse for the male sex. These juices can come into existence in the organism under the most different circumstances. But they certainly do come into existence, if we can so feed the mother that we cannot find in her urine even the faintest trace of sugar, but instead of it an increased excretion of reducing substances, _accompanied by a relatively high exchange of nitrogenous substances_. These facts can, therefore, serve us only as a symptom of processes taking place in the organism. In consequence our task will be to follow up in the various cases the conditions of this symptom, _in order that we may try so to feed the mother individual that she may attain to giving the effective impulse_; and this we have certainly accomplished by the increased excretion of the reducing substances and the disappearance of the normal urine-sugar. When we have brought a woman into such a condition that she excretes no sugar, and by the continuation of the same diet keep her permanently in that condition, the ovule which is being developed in her organism will develop itself correspondingly. Also with this diet the different qualities of the organism may not be altogether without influence on the course of the ovum’s development. In many cases the quantity of sugar in the urine excreted does not diminish. The most different kinds of diet may be tried, and yet the phenylhydrazin test will always show the presence of sugar. Individuals of this sort exhibit a certain obstinacy in resisting the attempt to procure an alteration of the metabolism. In such cases no influence has been exerted over the development of the ovum. In these experiments which are made with the mother, not only is the ovum influenced which is being developed for fertilization in the maternal organism, but it is also possible for the mother herself, in consequence of the alteration of diet, to experience many changes with regard to the physical peculiarities of the elements which compose her body. The treatment may prove highly beneficial to the mother herself, so that not ovulation alone is subjected to an alteration, but the activity of the processes of the tissues of the other organs of the body may be also simultaneously in some way changed. And here may come into consideration many other factors which may produce a particular fitness for procreation and for the development of the ovum, and, if they once make themselves felt, may be of the greatest advantage to the mother.