A laboratory model of the regeneration of the inorganic nutrient salts of phosphorus, nitrogen, and silicon from diatom cells decaying in the dark while subject to bacterial attack was studied. The system was analyzed for phosphate, dissolved and particulate organic phosphorus, ammonia, nitrite, nitrate, dissolved and particulate nitrogen, and orthosilicate concentrations. The observations extended over a period of more than one year, but the significant changes appear to have been restricted to the first five months....