y changes; and that, possibly, if we include under the formula
hereditarily-transmitted adaptations, all subsequent differentiations
may be similarly determined. Well, we need not long contemplate the
facts to see that some of the predominant social differentiations are
brought about in an analogous way. As the members of an
originally-homogeneous community multiply and spread, the gradual
separation into sections which simultaneously takes place, manifestly
depends on differences of local circumstances. Those who happen to
live near some place chosen, perhaps for its centrality, as one of
periodical assemblage, become traders, and a town springs up; those who
live dispersed, continue to hunt or cultivate the earth; those who
spread to the sea-shore fall into maritime occupations. And each of
these classes undergoes modifications of character fitting to its
function. Later in the process of social evolution these local
adaptations are greatly multiplied. In virtue of differences of soil and
climate, the rural inhabitants in different parts of the kingdom, have
their occupations partially specialized; and are respectively
distinguished as chiefly producing cattle, or sheep, or wheat, or oats,
or hops, or cider. People living where coal-fields are discovered become
colliers; Cornishmen take to mining because Cornwall is metalliferous;
and the iron-manufacture is the dominant industry where ironstone is
plentiful. Liverpool has assumed the office of importing cotton, in
consequence of its proximity to the district where cotton goods are
made; and for analogous reasons Hull has become the chief port at which
foreign wools are brought in. Even in the establishment of breweries, of
dye-works, of slate-quarries, of brick-yards, we may see the same truth.
So that, both in general and in detail, these industrial specializations
of the social organism which characterize separate districts, primarily
depend on local circumstances. Of the originally-similar units making up
the social mass, different groups assume the different functions which
their respective positions entail; and become adapted to their
conditions. Thus, that which we concluded, _a priori_, to be the leading
cause of organic differentiations, we find, _a posteriori_, to be the
leading cause of social differentiations. Nay further, as we inferred
that possibly the embryonic changes which are not thus directly caused,
are caused by hereditarily-transmitted adaptations