The resources of a country, so far as concerns population, become less as the period of peace-disturbance is prolonged.

Mayo-Smith quotes von Mayr in the following example of the influence of the war of 1870-71 on the birth-rate in Bavaria,--the figures for births are thrown back nine months, so as to show the time of conception: Before the war under normal conception the number of births was about 16,000 per month.
During the war it sank to about 2000 per month.

Immediately on the cessation of hostilities it arose to its former number, while the actual return of the troops brought an increase of 2000 per month.

The maximum was reached in March, 1872, when it was 18,450.

The war of 1866 seems to have passed over Germany without any great influence, the birth-rate in 1865 being 39.2; in 1866, 39.4; in 1867, 38.3; in 1868, 38.4.On the other hand, while the birth-rate in 1870 was 40.1, in 1871 it was only 35.9; in 1872 it recovered to 41.1, and remained above 41 down to 1878.