The great body of migrants proceed only a short distance.
The process of absorption goes on as follows: The inhabitants of the country immediately surrounding a town of rapid growth flock into it; the gaps thus left in the rural population are filled up by migrants from more remote districts, until the attractive force of one of the rapidly-growing cities makes its influence felt, step by step, to the most remote corner of the land.
Migrants enumerated in a certain centre of absorption will consequently grow less with the distance, proportionately to the native population which furnishes them.
Migrants proceeding long distances generally go by preference to one of the great cities of commerce or industry.
Here, too, breed many species of ducks, the mallard, gadwall, baldpate, three species of teal, shoveler, pintail, hooded mergansers, and Canada geese; other ducks and geese are migrants only.
On the contrary, the effect of the inflow of adult migrants is very marked, as is to be expected, in the returns for the new countries, such as the United States, Canada and Australasia.
Since 1900 a considerable number of Syrians and Lebanese migrants have settled in the country as traders.