Barely significant growth has been obtained in cultures of Phytophthora parasitica containing d-alanine as the sole source of nitrogen, but abundant growth in those containing l-alanine. Growth was found to increase as the level of l-alanine was elevated from 0.2 to 0.8%, although 0.2% represents a greater quantity than is removed by the fungus. In experiments the growth of Verticillium albo-atrum was shown to be supported by d-alanine, although much less efficiently than by the laevo form.