ANALOGY OF THE LOWEE CrRCULATIONS. 401 



usually happens, they cover a surface of country not every- 

 where alike in its products — when, more especially, there 

 arise considerable classes that are not industrial; some pro- 

 cess of exchange and distribution inevitably arises. Trav- 

 ersing here and there the earth's surface, covered by that 

 vegetation on which human life depends, and in which, a8 

 we say, the units of a society are imbedded, there are 

 formed indefinite paths, along which some of the necessa- 

 ries of life occasionally pass, to be bartered for others 

 which presently come back along the same channels. Note, 

 however, that at first little else but crude commodities are 

 thus transferred — fruits, fish, pigs or cattle, skins, etc. : 

 there are few, if any, manufactured products or articles 

 prepared for consumption. And note further, that such 

 distribution of these unprepared necessaries of life as takes 

 place, is but occasional — goes on with a certain slow, irregu- 

 lar rhythm. 



Further progress in the elaboration and distribution of 

 nutriment, or of commodities, is a necessary accompani- 

 ment of further difiTerentiation of functions in the indivi^ 

 dual body or in the body politic. As fast as each organ of 

 a living animal becomes confined to a special action, it must 

 become dependent on the rest for all those materials which 

 its position and duty do not permit it to obtain for itself; 

 in the same way that, as fast as each particular class of a 

 community becomes exclusively occupied in producing its 

 own commodity, it must become dependent on the rest foi 

 the Other commodities it needs. And, simultaneously, a 

 more perfectly-elaborated blood will result from a highly- 

 specialized group of nutritive organs, severally adapted to 

 prepare its difierent elements ; in the same way that the 

 stream of commodities circulating throughout a society, 

 will be of superior quality in proportion to the greater di- 

 vision of labour among the workers. Observe, also, that 

 in either case the circulating mass of nutritive materials, 



