Mayo-Smith, in remarking on the influence of war on the marriage-rate, says that in 1866 the Prussian rate fell from 18.2 to 15.6, while the Austrian rate fell from 15.5 to 13.0. In the war of 1870-71 the Prussian rate fell from 17.9 in 1869 to 14.9 in 1870 and 15.9 in 1871; but in the two years after peace was made it rose to 20.6 and 20.2, the highest rates ever recorded. In France the rate fell from 16.5 to 12.1 and 14.4, and then rose to 19.5 and 17.7, the highest rates ever recorded in France. Influence of Rural and Urban Life.--Rural districts are always very prolific, and when we hear the wails of writers on "Social Economy," bemoaning the small birth-rates of their large cities, we need have no fear for urban extinction, as emigration from the country by many ambitious sons and daughters, to avail themselves of the superior advantages that the city offers, will not only keep up but to a certain point increase the population, until the reaction of overcrowding, following the self-regulating law of compensation, starts a return emigration. The effect of climate and race on prolificity, though much spoken of, is not so great a factor as supposed. The inhabitants of Great Britain are surpassed by none in the point of prolificity; yet their location is quite northern. The Swedes have always been noted for their fecundity. Olaf Rudbeck says that from 8 to 12 was the usual family number, and some ran as high as 25 or 30. According to Lord Kames, in Iceland before the plague (about 1710) families of from 15 to 20 were quite common. The old settlers in cold North America were always blessed with large families, and Quebec is still noted for its prolificity. There is little difference in this respect among nations, woman being limited about the same everywhere, and the general average of the range of the productive function remaining nearly identical in all nations. Of course, exception must be made as to the extremes of north or south. Ancient and Modern Prolificity.--Nor is there much difference between ancient and modern times. We read in the writings of Aristotle, Pliny, and Albucasis of the wonderful fertility of the women of Egypt, Arabia, and other warm countries, from 3 to 6 children often being born at once and living to maturity; but from the wonder and surprise shown in the narration of these facts, they were doubtless exceptions, of which parallels may be found in the present day. The ancient Greek and Roman families were no larger than those of to-day, and were smaller in the zenith of Roman affluence, and continued small until the period of decadence.