IN THE 1936 edition of that admirable reference volume, The Municipal Yearbook, a new section was begun, entitled Professionalization of the Municipal Service. This section was composed of twenty-four pages and discussed eleven types of professions among municipal employees. Some of these were old professions, which had been organized for many years; others were much newer. School superintendents, city managers, librarians, public works directors, municipal finance officers, recreation directors, public welfare directors, assessors, purchasing agents, fire chiefs, and police chiefs were listed, in that order. That the professionalization of the public service at all levels has proceeded apace, before that date and since, few would question. By 1939, the Yearbook listed nineteen types of professions and spoke of their rocketing membership. There are more and more different professions. Old professions are branching and becoming differentiated. Vocations that might once have been classified in the skilled trade