the excess of nutrition over waste in a living
body. Moreover, in both cases when the functional activity is high and
the nutrition defective, there results not growth but decay. If in an
animal, any organ is worked so hard that the channels which bring blood
cannot furnish enough for repair, the organ dwindles: atrophy is set up.
And if in the body-politic, some part has been stimulated into great
productivity, and cannot afterwards get paid for all its produce,
certain of its members become bankrupt, and it decreases in size.

One more parallelism to be here noted, is that the different parts of a
social organism, like the different parts of an individual organism,
compete for nutriment; and severally obtain more or less of it according
as they are discharging more or less duty. If a man's brain be
overexcited it abstracts blood from his viscera and stops digestion; or
digestion, actively going on, so affects the circulation through the
brain as to cause drowsiness; or great muscular exertion determines such
a quantity of blood to the limbs as to arrest digestion or cerebral
action, as the case may be. So, likewise, in a society, great activity
in some one direction causes partial arrests of activity elsewhere by
abstracting capital, that is commodities: as instance the way in which
the sudden development of our railway-system hampered commercial
operations; or the way in which the raising of a large military force
temporarily stops the growth of leading industries.

* * * * *

The last few paragraphs introduce the next division of our subject.
Almost unawares we have come upon the analogy which exists between the
blood of a living body and the circulating mass of commodities in the
body-politic. We have now to trace out this analogy from its simplest to
its most complex manifestations.

In the lowest animals there exists no blood properly so called. Through
the small assemblage of cells which make up a _Hydra_, permeate the
juices absorbed from the food. There is no apparatus for elaborating a
concentrated and purified nutriment, and distributing it among the
component units; but these component units directly imbibe the
unprepared nutriment, either from the digestive cavity or from one
another. May we not say that this is what takes place in an aboriginal
tribe? All its members severally obtain for themselves the necessaries
of life in their crude states; and severally prepare them