Vicinism and mass effect in a historical perspective

The term vicinism, usually ascribed to R. Nordhagen, was probably first coined in 1903 by Hugo de Vries as a genetical term — in the framework of his mutation theory — and only two years later as an ecological concept by F.E. Clements. Since both terms are clearly defined and concern different phenomena it is better to distinguish between genetical and ecological vicinism, while the latter concept can be further subdivided in rhizome and seed vicinism.