'To the extent that the products created by B, B´, B´´, etc., (I) re-enter in their natural form into their own process, it goes without saying that a corresponding portion of their own surplus-product is transferred directly (without any intervention of circulation) to their productive capital and becomes an element of additional constant capital. To the same extent they do not help to convert any surplus-product of A, A´, A´´ etc., (I) into money. Aside from this, where does the money come from? We know that they have formed their hoard in the same way as A, A´, etc., by the sale of their respective surplus-products. Now they have arrived at the point where their accumulated hoard of virtual money-capital is to enter effectually upon its function as additional money-capital. But this is merely turning around in a circle. The question still remains: Where does the money come from, which the various B's (I) withdrew from the circulation and accumulated?'[120] His prompt reply again seems surprisingly simple: 'Now we know from the analysis of simple reproduction, that the capitalists of I and II must have a certain amount of ready money in their hands, in order to be able to dispose of their surplus-products. In that case, the money which served only for the spending of revenue in articles of consumption returned to the capitalists in the same measure in which they advanced it for the purpose of disposing of their commodities. Here the same money reappears, but in a different function. The A's and B's supply one another alternately with the money for converting their surplus-product into virtual additional capital, and throw the newly formed money-capital alternately into circulation as a medium of purchase.'[121]