children born to the class of casual laborers and unskilled workers is pretty certain to take place as rapidly as the knowledge of methods of birth control is extended; and at present it does not seem that this extension can be stopped by any of the agencies that are opposing it.
If the size of a family becomes more nearly proportional to the income, instead of being inversely proportional to it as at present, and if income is even roughly a measure of the value of a family to the community—an assumption that can hardly be denied altogether, however much one may qualify it in individual cases,—then the problem of taxing family incomes will be easier. The effect of income differences will be, on the whole, eugenic. It would then seem desirable to exempt from taxation all incomes of married people below a certain critical sum, this amount being the point at which change in income may be supposed to not affect size of family. This means exemption of all incomes under $2,000, an additional $2,000 for a wife and an additional $2,000 for each child, and a steeply-graded advance above that amount, as very large incomes act to reduce the size of family by introducing a multiplicity of competing cares and interests. There is also a eugenic advantage in heavy taxes on harmful commodities and unapprovable luxuries.
THE "BACK TO THE FARM" MOVEMENT
One of the striking accompaniments of the development of American civilization, as of all other civilizations, is the growth of the cities. If (following the practice of the U. S. Census) all places with 2,500 or more population be classed as urban, it appears that 36.1% of the population of the United States was urban in 1890, that the percentage had risen to 40.5 in 1900, and that by 1910 not less than 46.3%