The result of this enlargement is that if the newly acquired means of production are indeed to be used, the quantity of labour power must be increased correspondingly. Maintaining the previous ratio, the new constant capital of 153 requires a new variable capital of 31. This implies the necessity to capitalise a corresponding further amount of the surplus value. Thus the fund for the capitalists' personal consumption in Department II comes to be what remains of the surplus value (285_s_) after deduction of the amounts used for twice enlarging the constant capital (70 + 83) and a commensurate increase in the variable capital (31)--a fund of 101, after deducting a total of 184. Similar operations in the second year of accumulation result for Department II in its surplus value being divided into 158 for capitalisation and 158 for the consumption of its capitalists, and in the third year, the figures become 172 and 170 respectively. We have studied this process so closely, tracing it step by step, because it shows clearly that the accumulation of Department II is completely determined and dominated by the accumulation of Department I. Though this dependence is no longer expressed, as in Marx's first example, by arbitrary changes in the distribution of the surplus value, it does not do away with the fact itself, even if now the surplus value is always neatly halved by each department, one-half for capitalisation and the other for personal consumption. Though there is nothing to choose between the capitalists of the two departments as far as the figures are concerned, it is quite obvious that Department I has taken the initiative and actively carries out the whole process of accumulation, while Department II is merely a passive appendage. This dependence is also expressed in the following precise rule: accumulation must proceed simultaneously in both departments, and it can do so only on condition that the provisions-department increases its constant capital by the precise amount by which the capitalists of the means-of-production-department increase both their variable capital and their fund for personal consumption. This equation (increase II_c_ = increase I_v_ + increase I_s.c_.)[106] is the mathematical cornerstone of Marx's diagram of accumulation, no matter what figures we may choose for its concrete application. But now we must see whether capitalist accumulation does in actual fact conform to this hard and fast rule. Let us first return to simple reproduction. Marx's diagram, it will be remembered, was as follows: I. _4,000c + 1,000v + 1,000s = 6,000_ means of production II. _2,000c + 500v + 500s = 3,000_ means of consumption ----- 9,000 total production Here, too, we established certain equations which form the foundation of simple reproduction; they were: