ountries, but
strongly marked in northern countries (in Sweden the absolute maximum of
conceptions is reached in December), and is due, in the opinion of
Wappaeus, solely to social causes. Villerme reached somewhat similar
results. Founding his study on 17,000,000 births, he showed that in France
it was in April, May, and June, or from the spring equinox to the summer
solstice, and nearer to the solstice than the equinox, that the maximum of
fecundations takes place; while the minimum of births is normally in July,
but is retarded by a wet and cold summer in such a manner that in August
there are scarcely more births than in July, and, on the other hand, a
very hot summer, accelerating the minimum of births, causes it to fall in
June instead of in July.[152] He also showed that in Buenos Ayres, where
the seasons are reversed, the conception-rate follows the reversed
seasons, and is also raised by epochs of repose, of plentiful food, and of
increased social life. Sormani studied the periodicity of conception in
Italy, and found that the spring maximum in the southern provinces occurs
in May, and gradually falls later as one proceeds northward, until, in the
extreme north of the peninsula, it occurs in July. In southern Italy there
is only one maximum and one minimum; in the north there are two. The
minimum which follows the spring or summer maximum increases as we
approach the south, while the minimum associated with the winter cold
increases as we approach the north.[153] Beukemann, who studied the matter
in various parts of Germany, found that seasonal influence was specially
marked in the case of illegitimate births. The maximum of conceptions of
illegitimate children takes place in the spring and summer of Europe
generally; in Russia it takes place in the autumn and winter, when the
harvest-working months for the population are over, and the period of
rest, and also of minimum deathrate (September, October, and November),
comes round. In Russia the general conception-rate has been studied by
various investigators. Here the maximum number of conceptions is in
winter, the minimum varying among different elements of the population.
Looked at more closely, there are maxima of conceptions in Russia in
January and in April. (In Russian towns, however, the maximum number of
conceptions occurs in the autumn.) The special characteristics of the
Russian conception-rate are held to be due to the prevalence of marriages
in autumn