These are some of the main divisions of the economic system as it exists at the present time. Each division is a great net-work of economic inter-relations, specialized and subdivided into individual plants, factories, departments and the like. Take, as an example, one group, the manufacturing industries of the United States. When the Census of 1914 was compiled, the manufacturing industries were classed in fourteen groups,--food and food products, textiles, iron and steel and their products, lumber and its remanufactures, etc. There were 496,234 wage-earners working in 59,317 food and food products establishments, 1,498,644 wage-earners in 22,995 textile establishments, 1,061,058 individuals working in 17,719 iron and steel establishments, and so forth. Each of the fourteen subdivisions of the manufacturing industries of the United States employ hundreds of thousands of men and women who are at work in tens of thousands of establishments in thousands of cities and town. The same kind of specialization is to be found throughout the various modern industries, and in the different industrial countries. Each one of the larger establishments--each factory or plant--is in turn composed of departments, divisions, shops and the like. Whether the individual establishment or the individual department be regarded as the unit of economic activity, the outstanding feature of the manufacturing industry is the immense number of units that must be in working order and co-operating harmoniously with the others before the whole can function smoothly. And this is but one of the general divisions of industry. At the time of the Census of 1920 there were in the United States alone, 6,447,998 farms; in 1914 there were 275,791 manufacturing establishments; in 1910 there were 1,127,926 retail dealers and 50,123 wholesale dealers. Literally, there are millions of productive economic units in this one country which are specialized, which are associated in their activities and which must be put on a co-operative basis if effective results are to be obtained from them. 3. _Three Lines of Economic Organization_ So much, then, for the interdependence of the various economic groups under the present forms of society. This interdependence runs throughout the capitalist system. Farms depend on railroads, railroads on mines, mines on factories, factories on farms, and so on. This extreme specialization of the economic system is the product of the past two hundred years, the outcome primarily of the industrial revolution. The experience of society with these specialized economic forms does not, therefore, extend over more than five or six generations. This experience is sufficient, however, to indicate, that there are three general lines along which economic organization may develop: