1. In order to clarify the infinences of the salivary gland hormone on the hematopoietic function of bone marrow, especially on the erythrocyte series, the author studied changes in the erythrocyte count, hemoglobin countent and reticulocyte count in the rabbit fluid medium tissue culture to which Parotin was added directly, and the following results were obtained. As for the influences of Parotin on the erythrocyte count, hemoglobin countent and retieulocyte count in the tissue culture, no significant difference could be observed as compared with the control. 2. When Parotin was added directly to the bone-marrow tissue culture of normal ginea pigs, the megakaryocyte function was accelerated, and likewise in the bone-marrow tissue culture of normal persons, Parotin enhanced the megakaryocyte function.