To class human labor-power with pig iron as a commodity, subject to the same laws, may at first seem fantastic to the reader, but a careful survey of the facts will fully justify the classification. The capacity of the worker to labor depends upon his securing certain things; his labor-power has to be reproduced from day to day, for which a certain supply of food, clothing, and other necessities of life is essential. Even with these supplied constantly, the worker sooner or later wears out and dies. If the race is not to be extinguished, a certain supply of the necessities of life must be provided for the children during the years of their development to the point where their labor-power becomes marketable. The average cost of production in the case of labor-power includes, therefore, the necessities for a wife and family as well as for the individual worker. Far from being the iron law Lassalle imagined, this law of wages is one of considerable elasticity. The standard of living itself, far from being a fixed thing, determined only by the necessities of physical existence, varies according to occupational groups; to localities sometimes, as a result of historical development; to nationality and race, as a result of tradition; to the general standard of intelligence, and the degree in which the workers are organized for the promotion of their economic interests. The advance in the culture of the people as a whole, expressing itself in legislation for compulsory education, the abolition of child labor, improvement of housing and general sanitary conditions, and so on, tends to raise the standard of living. Finally, the fluctuations in the price of labor-power due to the operation of the law of supply and demand are much more important than Lassalle imagined.