In so far as these theories are mere calculations and results which have originated from comparisons of numbers (the numbers themselves being in many cases of no practical value), the conclusions reached may appear to be astonishing, and may be used to support either one view or another, or to contradict them. Only one fact appears to be certainly established, that, on an average, under normal circumstances, the number of male individuals of our population that are born exceeds the number of females. The difference amounts to a small and variable number per cent., but in the case of the new-born, the excess is on the side of the males. (Süssmilch.) * * * * * Thus far we have given such data as statistics have furnished. These, it is true, belong principally to past epochs, and no new results of this sort have been used by statisticians. But it would be equally impossible to deduce from new statistics, or from old, or from both together, any law of nature affecting the question before us. * * * * * I shall proceed next to examine the further theories on this subject with which I have become acquainted from the perusal of the literature treating of it. With some of the works which I am about to mention I am acquainted at first hand. Others I know only from quotations found in various technical publications. I have not attempted to arrange my materials in any other way. 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.