Not in every branch of industry are there large scale enterprises; and, moreover, a very important feature of capitalism in its highest stage of development is the so called combine, that is to say, the grouping in a single enterprise of different branches of industry, which either represent the consecutive stages in the working up of raw materials (for example, the smelting of iron ore into pig iron, the conversion of pig iron into steel, and then, perhaps, the manufacture of steel goods) or are auxiliary to one another (for example, the utilization of waste or of by products, the manufacture of packing materials, etc.