B. Asia.
In Palestine puberty most commonly occurs at the age of 13; in Turkey even as early as 10. Rouvier calculated the average of 742 cases observed in Syria to be the age of 12. As regards Persian women, the data vary between the age of 14 for the northern part of the country and the age of 9 or 10 for the southern. According to Joubert’s data in 46.4 per cent. of the indigens of India, menstruation begins at the age of 12 or 13. Similar figures are given for Ceylon and for Siam. In Japan menstruation most frequently begins at the age of 14, sometimes as early as 13; mothers of 15 are by no means rarities in this country, but for menstruation to begin before the age of 12 is considered a very exceptional occurrence. According to a table dealing with 584 women of Tokio menstruation began:
| At the age of: | |
|---|---|
| 11 years in | 2 instances. |
| 12 years in | 2 instances. |
| 13 years in | 26 instances. |
| 14 years in | 78 instances. |
| 15 years in | 224 instances. |
| 16 years in | 228 instances. |
| 17 years in | 68 instances. |
| 18 years in | 44 instances. |
| 19 years in | 10 instances. |
| 20 years in | 2 instances. |
The data available regarding China are so exceedingly variable that little importance can be attached to them.
C. Africa, Oceania, and America.
The average age at which menstruation begins in the negro women of Africa is from 10 to 13. In Algeria puberty occurs at 9 or 10 years. Among the Australian indigens, menstruation commonly begins as early as 8 years, and at the very latest at the age of 12 years. The data available concerning the indigens of the Oceanic Archipelago are extremely variable and inexact, but we cannot go far astray in stating the age of puberty among these to be from 10 to 13. In tropical South America girls begin to menstruate from the age of 9 to 14 years. The Indian women of North America begin to menstruate at the ages of 12, 13, 14, or even as late as 18 or 20. In the Arctic zone of North America and in Greenland the onset of menstruation is delayed till 17 and even till 23 years.
As regards the position in life and the upbringing years it has been shown by numerous observers that among the well-to-do classes, whose mode of living is luxurious, and whose social circumstances allow free play to the imagination, menstruation begins at an earlier age than among the working classes, whose life is one of want and privation. According to the statistical data of Mayer’s regarding 6,000 women, menstruation began:
| In women of the upper classes. | In women of the lower classes. | |
|---|---|---|
| At the age of 13 years | 11.73 per cent. | 7.06 per cent. |
| At the age of 14 years | 23.90 per cent. | 13.33 per cent. |
| At the age of 15 years | 22.83 per cent. | 14.56 per cent. |
| At the age of 16 years | 14.10 per cent. | 16.53 per cent. |
| At the age of 17 years | 9.60 per cent. | 13.33 per cent. |
From this table we learn that in nearly one-fourth of the girls of the upper classes puberty occurs at the age of 14, whilst in girls of the lower classes barely one-sixth begin to menstruate at this age. The average age at the first menstruation in girls belonging to the upper classes is seen to be 14.69 years, but in girls belonging to the lower classes, 16.00 years. According to other observers the average age at the first menstruation is:
| Brierre de Boismont. (Paris.) | Tilt. (London.) | Krieger. (Berlin.) | Ravn. (Copenhagen.) | |
|---|---|---|---|---|
| Amongst gentle folk and the rich | 13y. 8m. | 13y. 5½m. | 14y. 1m. | 14y. 3m. |
| Amongst the well-to-do middle classes | 14y. 5m. | 14y. 3½m. | 15y. 5m. | 15y. 5½m. |
| Amongst the lower classes | 14y. 10m. | 16y. 8m. | 16y. 5½m. |