In the eighteenth century Wargentin showed that, in Sweden more children were born in one month than in another.[155] The same has since been found to be the case in other European countries. According to Wappäus, the number of births in Sardinia, Belgium, Holland, and Sweden is subject to a regular increase twice a year, the maximum of the first increase occurring in February or March, that of the second in September and October.[156] M. Sormani observed that, in the south of Italy, there is an increase only once in the year, but more to the north twice, in spring and in autumn.[157] Dr. Mayr and Dr. Beukemann found in Germany two annual maxima—in February or March, and in September;—[158]and Dr. Haycraft states that, in the eight largest towns of Scotland, more children are born in legitimate wedlock in April than in any other month.[159] As a rule, according to M. Sormani, the first annual augmentation of births has its maximum, in Sweden, in March; in France and Holland, between February and March; in Belgium, Spain, Austria and Italy, in February; in Greece, in January; so that it comes earlier in southern Europe than farther to the north.[160] Again, the second annual increase is found more considerable the more to the north we go. In South Germany it is smaller than the first one, but in North Germany generally larger;[161] and in Sweden, it is decidedly larger.[162] As to non-European countries, Wappäus observed that in Massachusetts, the birth-rate likewise underwent an increase twice a year, the maxima falling in March and September; and that in Chili many more children were born in September and October—_i.e._, at the beginning of spring—than in any other month.[163] Finally, Mr. S. A. Hill, of Allahabad, has proved, by statistical data, that, among the Hindus of that province, the birth-rates exhibit a most distinct annual variation, the minimum falling in June and the maximum in September and October.[164] This unequal distribution of births over the different months of the year is ascribed to various causes by statisticians. It is, however, generally admitted that the maximum in February and March (in Chili, September) is, at least to a great extent, due to the sexual instinct being strongest in May and June (in Chili, December).[165] This is the more likely to be the case as it is especially illegitimate births that are then comparatively numerous. And it appears extremely probable that, in Africa also, the higher birth-rates in the seasons of the early rains owe their origin to the same cause.