This diet should be continued for a considerable time, even although the sugar in the urine may have disappeared. It is best to begin the change of diet a good while (about 2 or 3 months) before impregnation. During the menstruations which fall within this period, the ripened ova will be voided unfertilized, and new ova which have been influenced by the altered conditions of nutrition in the organism will ripen in their place. (If we follow such information as we have concerning the development of sex in man, we thence conclude that the difference in sex appears at the beginning of the third month of pregnancy, and is definitely expressed in the fourth month. From this it would appear not to be superfluous if the recommended alteration of diet was maintained until the beginning of the third month.) When the ovule of a human female, dieted in this way, becomes fertilized, it has been so far ripened by the process of nutrition conducted in the organism of the mother, that when it attains the stage of development, it resolves itself into cells which compose an organism containing male characteristics. After impregnation it is still advantageous that whilst the condition of the urine is examined at intervals of a few days, the corresponding diet should be continued during the advancing stages of the development. Although I do not here take the trouble to illustrate these diet processes by explanations, every one can have regard to these particulars for himself, and conduct the diet even after impregnation has taken place in accordance with the information given above. In a case like that mentioned, where, after marriage, female ova were successively formed and developed, practically a process of physiological combustion was going on in the mother which did not suffice for deriving all the advantage possible from the food, so that the available elements might be all oxidized. In consequence, only female ova were fertilized and only female individuals born. This condition of things remained the same for a number of years. In such a case the question is not alone one of a small residuum of sugar, but in addition to this it is probably not impossible that other substances also were evacuated from the body, to make use of which was not within the power of the process of combustion. With a rational diet, these substances also might be withheld from evacuation and, as well as the sugar, be made available for combustion with a corresponding increase of nourishment. In experiments of this kind metabolic activity will show itself in the organism, as it may be perceived from the nitrogenous constituents of the urine that a greater exchange of nutritive matter is taking place, a thing that happens also with normal individuals. Under these circumstances the specific gravity of the urine is also increased, and it may sometimes become relatively considerable (1030 to 1035).