ABSTRACT
Originally developed by Schuchardt (1868) and perhaps independently, though later, by Schmidt (1872), image used to explain the origin and development of individual languages through gradual linguistic differentiation and not-as in Schleicher’s genetic tree theory-through abrupt branching. A nucleus of innovation is postulated which radiates outwards in the form of waves and spreads linguistic changes and developments, much like waves that are emitted and partly overlap when stones are dropped in water. Language varieties that are spatially and/ or temporally neighboring accordingly usually display a language inventory with correspondences common in many areas.
