1) When 0.5 gram per body weight kilogram of homogeneous red bone marrow was embedded to normal rabbits at the inner part of thigh, both the hemoglobin and the number of erythrocyte showed a temporary reduction, followed by a remarkable and comparatively long-lasting increase of them. In this connection, the increase of reticulocyte was, prior to that of erythrocyte, also notably found. 2) The same response was shown also in the case of embedding 0.3 gram per body weight kilogram, but in this case the response was rather slight. 3) In the case of embedding 1.0 gram per body weight kilogram, only the anemia was resulted, no increase of erythrocyte being caused. 4) The same response as in the first imbedding was found in another experiment under the same condition (0.5 gram per body weight kilogrem), but this time the reduction of erythrocyte on early stage was slight and no particular disorder was noted. 5) When 0.5 gram per body weight kilogram of heterogeneous (- of a young dog -) red bone marrow was embedded to normal rabbits, the response was almost the same with the case of embedding homogeneous one, although the respose in slighter degree. 6) In the cases of embedding 0.5 gram per body weight kilogram both of homogeneous and heterogeneous muscles instead of red bone marrow, the blood-picture of embedded body did not show any notable change. 7) Judging from above experiences, the fact has become clear that the imbedding of bone marrow has its peculiar function inpromoting the production of blood, and that the fittest puantity of it is 0.5 gram per body weight kilogram.