314 NATURE OF CAPITAL AND INCOME [Cmar. XVI 
In Figure 25 all the teeth below the top layer are rep- 
resented to be interactions. But if any of them should 
be final services, they need only be carried forward by dotted 
lines to the top, as in Figure 26. Or if the capital repre- 
sented by one layer interacts with the capital represented 
by a layer two or more removes above it, the connection 
Q 
  
Fia. 26. 
will be represented by carrying forward the tooth by dotted 
lines to the proper stage. 
As we are at present interested in the general aspects 
of the subject, we need not take into account such complica- 
tions, but may assume, for purposes of exposition, that all 
capital can be arranged in a single definite series, each mem- 
ber of which acts upon the one above it, and so on to the 
end. In the actual world, it is usually possible to arrange 
capital roughly in such an interacting series. 
§ 6 
Two special applications may be made of the foregoing 
representation for the summation of capital curves. The 
first will show the total value of capital property and the 
total value of income possessed by a particular individual, 
and the second will show the same condition as to an entire 
society.