The advocates of this theory also point to the instance of the bees. With the bees, the larva of ordinary worker-bees are fed ordinary food, and do not develop sex; while the larva which is intended to produce the queen-bee is fed specially nutritious "royal food," and consequently develops larger size and full female sex powers. If the queen is killed, or dies, the hive of bees proceeds to produce a new queen by means of feeding a selected larva with the "royal food" and thus developing full femaleness in it. It is said by some authorities that in cases in which some other of the larva accidently receive, through mistake, crumbs of the "royal food," they, too, grow to an extraordinary size, and develop fertility. This fact is held by the advocates of the nutrition theory to go toward establishing the fact that abundant nourishment of the embryo, during the neutral stage, tends to produce femaleness in it. They also claim that caterpillars which are very poorly nourished before entering into the chrysalis stage usually develop into male butterflies, while those highly nourished in the said stage tend to become females. Experiments on sheep have shown that when the ewes are particularly well nourished the offspring will show a large proportion of females.

A writer, favoring the theory in question, says: "In general, it is reasonable to infer that the higher sexual organization which constitutes the female is to be attained in the greatest number of cases by embryos which have superior vital conditions during the formative period. Among human beings, some facts of general observation become significant in the light of the foregoing inferences. After epidemics, after wars, after seasons of privation and distress, the tendency is toward a majority of male births. On the other hand, abundant crops, low prices, peace, contentment and prosperity tend to increase the number of females born. Mothers in prosperous families usually have more girls; mothers in families of distress have more boys. Large, well-fed, fully developed, healthy women, who are of contented and passive disposition, generally become mothers of families abounding in girls; while mothers who are small or spare of flesh, who are poorly fed, restless, unhappy, overworked, exhausted by frequent childbearing, or who are reduced by other causes which waste their vital energies, usually give birth to a greater number of boys. As a general proposition, the facts and inferences tend to establish the truth of the doctrine with women, that, the more favorable the vital conditions of the mother during the period in which the sex of her offspring is being determined, the greater the ratio of females she will bear; the less favorable her vital conditions at such times, the greater will be her tendency to bear males. That many apparent exceptions occur does not disprove the general tendency here maintained. Moreover, it is impossible to know in all cases what were the conditions of the mother's organism at the time in which her child was in its delicate balance between predominant femaleness and maleness; else many cases which seemingly disprove the proposition would be found to be forcible illustrations of its truth. Still further, it is probable that other causes besides those here mentioned act with greater or less effect in determining the sex of offspring."

Based upon this general theory of the relation of nutrition to sex-determination, many methods and systems have been devised by as many authorities, and have been followed and promulgated by as many schools. Without going into the almost endless detail which would be necessitated by a synopsis of these various methods and systems, it may be said that they all consist of plans having for their object the decrease of nutrition of the woman in cases in which male children are desired, and the increase of nutrition in cases in which female children are sought for. This increase or decrease in nutrition is enforced for a reasonable period before the time selected for the conception of the child, and also for a reasonable period after the time of conception. The decrease in nutrition does not consist of "starvation," but rather of a "training diet" similar to that followed by athletics, and from which dietary all rich foods, sweets, etc., are absent. In fact, the average dietary advocated by the "Eat and Grow Thin" writers would seem to be almost identical with that of the "male offspring" theorists.

Many persons who have followed the methods and systems based on the nutrition theory above mentioned claim to have been more or less successful in the production of the particular sex desired, but many exceptions to the rule are noted, and some writers on the subject are disposed to regard the reported successes as mere coincidences, and claim that the failures are seldom reported while the successes are widely heralded. The present writer presents the claims of this school to the attention of his readers, but without personally positively endorsing the idea. He is of the opinion that the data obtainable is not as yet sufficient to justify the strong claims made for the theory in some quarters; but, at the same time, he does not hesitate to say that there are many points of interest brought out in the presentation of the theory, and that many thoughtful persons seem to accept the same as reasonably well established and logical.

Another theory which has been heard of frequently of late years is that in which it is held that the ova are expelled in alternating sex, each month. Thus, if a male ovum is expelled in January, the February ovum will be a female one, according to this theory. Under this theory if the date of conception of a child be ascertained, and the sex of the child noted at its birth, it is a simple matter to count forward from the menstrual period following which the child was conceived, and thus determine whether the ovum of any succeeding period is male or female. It should be noted, however, that the periods are regulated by the lunar months, and not the calendar months. The fact that twins of different sexes are sometimes born would seem to disturb this theory—but not more than any other theory of sex-determination voluntarily produced, for that matter. The several schools explain this apparent discrepancy by the familiar saying that "exceptions prove the rule."

Another theory of sex-determination is that which holds that when conception occurs within a few days after the last day of menstruation, the child will be a girl; and that when conception occurs at a later period, the child will be a boy. Methods and systems based upon this theory are also reported as being reasonably successful in producing satisfactory results. But, inasmuch as there appears to be a great difference in individual women in this respect (even according to the claims of this school of sex-determination), it would seem that it would be difficult to proceed with certainty in the matter in most cases. One of the writers advocating this method, says: "Conception within five days after the end of the menstrual period is almost certain to produce a girl child; within five days to ten days, it may be either a boy or a girl; from ten to fifteen days, it is almost sure to be a boy; from eighteen to twenty-five days is the period of probable sterility, in which conception is extremely unlikely to occur."

In conclusion, it may be said that Nature undoubtedly has certain rules of sex-determination which govern in these cases; and that it is possible if not indeed probable that these rules may some day be discovered by man, and turned to account; but that it is very doubtful whether the secret has as yet been solved by the investigators. The writer may be pardoned for suggesting that, in his opinion, if the discovery is ever made it will likely be found to be very simple—so simple that we have probably overlooked it because it was in too plain sight to attract our attention. Nature's methods are usually very simple, when once discovered. She hides her processes from man by making them simple, it would seem.

LESSON X
WHAT BIRTH CONTROL IS, AND IS NOT

The student of the progress of human affairs, or even the average person whose knowledge of the doings of mankind is derived from a hasty and casual reading of the daily newspapers and the popular magazines, cannot plead ignorance of the growing interest in the general subject which is embraced within the content of the term "Birth Control."