From early antiquity, the forecasting of the sex of the unborn child has been a matter to occupy the minds not only of physicians and biologists, but also of the public. The subject is mentioned as far back as the Jewish Talmud,1 and reference to it crops up through intervening centuries down to the present.
Most of these conjectures, founded as they were on the insufficient data of ignorance, or plainly old wives' tales or traditions, carried no measure of conviction; but as our acquaintance with histology and biology spread and scientific minds lent themselves to the study of the question, somewhat more exact data were brought to light. In 1828, Girou de Buzareingues2 wrote a monograph on this subject. In 1863, Thury3 enunciated his "law," and within the last fifteen years Caullery,4 Kushakewitsch,5 Morgan6 and others have contributed to the literature of the