Precocious menstruation is seen from birth to nine or ten years. Of course, menstruation before the third or fourth year is extremely rare, most of the cases reported before this age being merely accidental sanguineous discharges from the genitals, not regularly periodical, and not true catamenia. However, there are many authentic cases of infantile menstruation on record, which were generally associated with precocious development in other parts as well. Billard says that the source of infantile menstruation is the lining membrane of the uterus; but Camerer explains it as due to ligature of the umbilical cord before the circulation in the pulmonary vessels is thoroughly established. In the consideration of this subject, we must bear in mind the influence of climate and locality on the time of the appearance of menstruation. In the southern countries, girls arrive at maturity at an earlier age than their sisters of the north. Medical reports from India show early puberty of the females of that country. Campbell remarks that girls attain the age of puberty at twelve in Siam, while, on the contrary, some observers report the fact that menstruation does not appear in the Esquimaux women until the age of twenty-three, and then is very scanty, and is only present in the summer months. Cases of menstruation commencing within a few days after birth and exhibiting periodical recurrence are spoken of by Penada, Neues Hannoverisehes Magazin, Drummond, Buxtorf, Arnold, The Lancet, and the British Medical Journal.