The exarnination of possibility that the dairy performance may be predicted by means 6f the induced lactation by the injection with synthetic estr9gen in virgin goats are being carried out. Results on the induced lactation and mammary developnlent in this report are briefy summ.arized as follows. ( 1 ) Sixteen virgin gaoatling were injected subcutaneously with 0.25mg. Diethylstilbestrol in oil daily for 20 days ahd the induced lactation was examined. ( 2 ) The lactation qurves showed various individual differences, but they might be classified generally it) 3 types; the first, daily yield increased rapidly and was followed by slower inprease to the maximum, the, second, it increased moderately with the constant rate to the maximum, and the third, it increased very slowly and the maximum was not so high as the formers. Further, such, results as the coefiicient of regression line at ' rapid increase, maximum yield, maximum period, duration, total yield and average daily yield may be notable. ( 3 ) The mammary d, evelopment was studied histol. ogical]y on 5 of the goats in such various periods as yearling breeding season-at dioestrum, out breeding season in the next year-5 days before the initial of treatment, the 11th day and 40th day after the initial of treatment. Results showed that such induced rrlilk was secreted from the normal like functional site of the gland-alveoli.