In Greece and other hot countries, it is said that the menses appear usually at nine or ten years of age. In the more temperate climates generally, as in Great Britain and our own country, the average age at which menstruation commences is from fourteen to fifteen years. Habits of life, also, have something to do with the evolution of this function. “The early or late appearance of the menses,” says Dr. Denman, “may depend upon the climate, the constitution, the delicacy and hardness of life, and upon the manners of those with whom young women converse.” High living, the use of stimulating food and drinks, living in populous cities, the habit of frequenting balls and theaters, and of being taught early in the habits of civic life, have all, doubtless, a considerable effect in rendering girls precocious as to menstruation. In Paris, girls are occasionally observed to become regular at ten, eleven, and twelve years. Velpeau knew one that menstruated at nine and a half years; another at ten and a half; and one young woman who at fourteen was as tall and robust as the majority of women at twenty, and had been entirely in a state of puberty since she was eight and a half years old. On the other hand, a country life and occupation, simplicity of manners, and frugal regimen, appear to be circumstances which procrastinate, to a greater or less extent, the coming on of the menstrual function. It is said that with the North American Indians this epoch does not commence until from the eighteenth to the twentieth year. A table showing the ages at which the menses appeared in 450 cases, as quoted by Dr. Maunsel, of Dublin, as having been given by Mr. Robertson in the Edinburgh Medical and Surgical Journal, is as follows: 10 first menstruated at 11 years 19 „ 12 „ 53 „ 13 „ 85 „ 14 „ 97 „ 15 „ 76 „ 16 „ 57 „ 17 „ 26 „ 18 „ 23 „ 19 „ 4 „ 20 „ ——— 450 total. According to this table, it will be seen that with the largest number, namely, 97, menstruation commenced at the age of fifteen; and nearly as many at sixteen as fourteen; so that we are to regard the average age in such a climate as Great Britain, Germany, France, and the United States, as being from fourteen to fifteen years. Dr. Meigs, of Philadelphia, gives a table on the authority of Drs. Boismont, of Paris, and Lee, of London, showing the ages at which 1,781 women began to menstruate, in France and England, as follows: