Economists and social historians have, of course, fully recognized the existence of economic groups. The fact of differentiation of this and of a more detailed kind is the primary feature of Prof. A. P. Usher’s theory of the development of the undertaker; and it is this fact which in economics is the raison d’être of exchange. Curiously enough, however, the existence of larger communities of interests—groups of groups—constituting classes has usually been denied. In history a very large field of political events has very little explanation that is worthy of the name unless we can assume the influence of some broad social grouping—a class. One evidence of this wider grouping is to be found in social habits and manners of life. Most persons can tell by instinct from his speech and manners and appearance to what social class a man may belong.