An intermediate stage between the first and second group is found in the periodical migrations. To this stage belong the migrations of farm laborers at harvest time, of the sugar laborers at the time of the campagne, of the masons of Upper Italy and the Ticino district, common day-laborers, potters, chimney-sweeps, chestnut-roasters, etc., which occur at definite seasons.

In this division the influence of the natural and political insulation of the different countries is, it is true, neglected. It must not, however, be overlooked that in the era of nationalism and protection of national labor political allegiance has a certain importance in connection with the objective point of the migrations. It would, therefore, in our opinion, be more just to make another division, taking as a basis the politico-geographical extent of the migrations. From this point of view migrations would fall into internal and foreign types.

Internal migrations are those whose points of departure and destination lie within the same national limits; foreign, those extending beyond these. The foreign may again be divided into continental and extra-European (generally transmaritime) emigration. One can, however, in a larger sense designate all migrations that do not leave the limits of the Continent as internal, and contrast with them real emigration, or transfer of domicile to other parts of the globe.

Of all these manifold kinds of migration, the transmaritime alone has regularly been the subject of official statistics; and even it has been but imperfectly treated, as every student of this subject knows. The periodic emigrations of labor and the peddling trade have occasionally been also subjected to statistical investigation—mostly with the secondary aim of legislative restriction. Yet these migrations from place to place within the same country are vastly more numerous and in their consequences vastly more important than all other kinds of migration put together.

Of the total population of the kingdom of Belgium there were, according to the results of the census of December 31, 1880, not less than 32.8 per cent who were born outside the municipality in which they had their temporary domicile; of the population of Austria (1890), 34.8 per cent. In Prussia, of 27,279,111 persons, 11,552,033, or 42.4 per cent, were born outside the municipality where they were domiciled. More than two-fifths of the population had changed their municipality at least once.

If we call the total population born in a given place and domiciled anywhere within the borders of the country that locality's native population, then according to the conditions of interchange of population just presented the native population of the country places is greater than their actual population; that of the cities, smaller.

A balancing of the account of the internal migrations in the grand duchy of Oldenburg gives the cities a surplus, and country municipalities a deficit, of 15,162 persons. In the economy of population one is the complement of the other, just as in the case of two brothers of different temperament, one of whom regularly spends what the other has laboriously saved. To this extent, then, we are quite justified from the point of view of population in designating the cities man-consuming and the country municipalities man-producing social organisms.

There is a very natural explanation for this condition of affairs in the country. Where the peasant, on account of the small population of his place of residence, is much restricted in his local choice of help, adjoining communities must supplement one another. In like manner the inhabitants of small places will intermarry more frequently than the inhabitants of larger places where there is a greater choice among the native population. Here we have the occasion for very numerous migrations to places not far removed. Such migrations, however, only mean a local exchange of socially allied elements.

This absorption of the surplus of emigration over immigration is the characteristic of modern cities. If in our consideration of this problem we pay particular attention to this urban characteristic and to a like feature of the factory districts—where the conditions as to internal migrations are almost similar—we shall be amply repaid by the discovery that in such settlements the result of internal shiftings of population receives its clearest expression. Here, where the immigrant elements are most numerous, there develops between them and the native population a social struggle—a struggle for the best conditions of earning a livelihood or, if you will, for existence, which ends with the adaptation of one part to the other, or perhaps with the final subjugation of the one by the other. Thus, according to Schliemann, the city of Smyrna had in the year 1846 a population of 80,000 Turks and 8,000 Greeks; in the year 1881, on the contrary, there were 23,000 Turks and 76,000 Greeks. The Turkish portion of the population had thus in thirty-five years decreased by 71 per cent, while the Greeks had increased ninefold.

Not everywhere, to be sure, do those struggles take the form of such a general process of displacement; but in individual cases it will occur with endless frequency within a country that the stronger and better-equipped element will overcome the weaker and less well-equipped.