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 for their own uses as well as they can. When there arises a decided differentiation between the governing and the governed, some amount of transfer begins between those inferior individuals who, as workers, come directly in contact with the products of the earth, and those superior ones who exercise the higher functions--a transfer parallel to that which accompanies the differentiation of the ectoderm from the endoderm. In the one case, as in the other, however, it is a transfer of products that are little if at all prepared; and takes place directly from the unit which obtains to the unit which consumes, without entering into any general current.