In the case of the most widely different branches of natural science, and whether the author’s aim be descriptive or experimental, it is a common practice to commence with a glimpse at what has been said by the earliest writers. I shall begin in the same way. I shall, however, not take into consideration what has been at various times mere folk-lore, and is only traditionally known, but shall limit myself to such traditions as have been preserved in writing. I have, besides, already spoken above of suppositions respecting the origin of sex which appear to partake of the nature of myths. To these it was impossible to attach any importance. And the same must be said of other views which belong to the epoch of the Greek or Latin writers on natural science, and are so strange that they can be scarcely brought into any agreement with modern knowledge.
In Ploss’s work ‘Das Weib in der Natur and Völkerkunde’ (Woman in Nature and Popular Tradition), are to be found the various speculations of different races respecting the origin of sex. Much of this folk-lore is of a distinctly surprising character, and calculated to afford the reader considerable amusement. For example, in Servia, if a man has a stye on his eyelid he comes to the conclusion that his aunt is pregnant. If the stye is on the upper eyelid, the child will be a male, if on the lower, a female.
Amongst the Asiatic races religious ceremonies, prayers, and similar expedients are considered efficacious, and capable of influencing the sex.
What question is there of the present day, respecting which we can consult the literature of the ancients, that does not take us back to the writings of Hippocrates, Aristotle, or Galen, or to those of the old authors of those oriental races whom we regard as the earliest cultivated peoples? Hippocrates held that to produce a male, the generative material must be of a stronger quality. The future destiny of the male rendered it necessary that it should be constructed on a stouter foundation. He must be capable of a stronger development, and must, therefore, be a product of stronger elements alike on the father’s and the mother’s side. A second hypothesis was soon added to this primary one, but without any foundation of facts.
According to Aristotle, the woman supplied the primary material for the development of the future individual. It was the function of the man to give the impulse, in consequence of which the future individual came into being. Next followed the purely mythical theory, already mentioned, in which Anaxagoras believed. The much-sought-for origin of the future difference of sex in the various individuals was assigned to the right or left side of the organism. And Galen even concluded that the right side of the body was the warmer, and the left the colder, further claiming for the warmer side the privilege of producing male individuals.
Various notions respecting the origin of sex have been also accommodated to these primitive theories of the ancients, without resting upon any positive foundation. No evidence exists to show from whom they originated, nor how they were disseminated. Nevertheless, the historical connection of these speculations justifies a reference to them, and various hypotheses of this kind will be found in a little publication of Dr. Heinrich Janke’s (Stuttgart, 1896). The older literature on the subject of the generation of the sexes has been collected by His. (Archiv für Anthropologie, Vol. IV. V.) In ‘Das Weib in der Natur and Völkerkunde’ (Leipzig), Ploss has collected ample information concerning both ancient and modern ideas on this subject amongst the different races of mankind. The procreative elements, furnished by the male and female organs, after their mixture, compete with each other, by virtue of their inherent forces, for the mastery. In this conflict, if the male molecules are the more numerous, a male results. On the contrary, if the female molecules are more numerous, the result is a female. Nicholaus Venette ascribes the difference of sex to the earliest phases of the life of the ovule.
The following aspect of the origin of sex is not without interest, although the theory rests on somewhat insufficient foundations, and is applicable, in the first instance, only to those creatures which produce but a single individual at a birth. Many creatures, and especially certain species of birds, present this phenomenon; they lay in a single month two eggs. Of these, one is male, the other female. In this way a provision is made for the equal increase, in each respective month, of both sexes. In the case of man, it would, in accordance with this, be anticipated that naturally an equal number of ova of either sex would be produced by a single individual.
This would lead to the supposition that, in the case of the human female, in one month a male ovule would reach its perfect development, and in the next month, anterior to the occurrence of the menses, a female ovule. Thus the ovary of the human female would contain in one month a male ovum capable of fecundation, and in the following month a similar female ovum. After a woman had once given birth to a child it would then be possible to form a correct idea of the distribution of the ova of the different sexes. The month of birth and the sex of the new-born child would be known, and starting from the datum that it would be the turn of the ovum of the next month to develop the opposite sex, it would be possible to fix the given month in which an individual of the male or female sex should be developed. (Dupuys.)