In the surging waves of the sea a grain of sand is carried into a clam by accident. The sensitive clam feels the intrusion immediately and begins to wriggle its soft inine tenderly and excrete fluid constantly. As time passes, nourished by the juice, the tiny grain grows into a glittering and translucent pearl.

The biologist tells us this is the course of the formation of the nucleated sea pearl. But I'm inclined to accept the sociological implication of a grain turning into a pearl. If a child absorbs nutrition incessantly from the beneficial cultural environment, sooner or later he will become a useful person like the grain-turned pearl.