1. The principle of light inhibition underlying the mechanism of potato formation is discussed in detail on the light of anthocyanin formation. 2. Our investigation of light inhibition is undertaken to determine whether the meristematic power in nuclear substances of bud cells enters inversely into the root system where certain abnormal meristematic activity may take place and protoplasm absorbs the excess quantity of carbohydrate. This is the most important problem in furture in the field of crop physiology. 3. Injection tests often showed that materials taken from root kernel treated by a special methods also control the growth of roots and accelerate the formation of anthocyanin.