Page:Popular Science Monthly Volume 26.djvu/340

 number of female births, as compared with the number of male births, increases as the birth-rate increases.

At the Cape of Good Hope the Boers are very prolific—six or seven is a small family, and from twelve to twenty children are not unusual; while the badly nourished and overworked Hottentots seldom have more than three children, and many of the women are barren, and Quetelet says that in 1813-'20 the free whites gave birth to 6,604 boys and 6,789 girls, or 97·2 boys to every 100 girls; while during the same time the Hottentot slaves produced 2,936 boys and 2,826 girls, or 103·9 boys to each 100 girls.

The birth-rate is higher in towns than in the country, and more boys are born for each hundred girls in the country than in the towns.

Thus, in Prussia, in 1881, the number of boy-births for each 100 girls was 106·36.

This table shows that in all the towns the ratio of boys was below the average for the whole of Prussia, and that in Berlin it was very much below the average.

Ploss was the first to point out that there is an excess of female births in time of prosperity, and he found that in Saxony the ratio of boy-births rose and fell with the price of food, and that the variation was most marked in the country.

It is well known that the number of conceptions among mankind is greater at some seasons of the year than at others, and from a record of nearly 10,000,000 births During has compiled the following table, which shows that the ratio of boy-births is greatest in three months when the birth-rate is smallest: