“…Gams 1918, Du Rietz 1921, Phillips 1931, Taylor 1935), but especially from the 1950s until the 1970s. Several theoretical statements were published, as for instance, the ones of Mörzer Bruyns (1950), Tischler (1950), Rabeler (1951), Gisin (1951), Grassé (1951), Quézel & Verdier (1953), Rioux (1958), among many others. An important reference is certainly Whittaker (1962) who produced an impressive synthesis of the question of biological communities, with an massive bibliography.…”